[Correlation between electrically-induced stapedius reflex and discomfort threshold in cochlear implant patients]. Electrically elicited stapedius reflex thresholds are an objective criteria for the fitting of speech processors in very young children. Reflex thresholds generally fit well within the upper third of a subject's individual dynamic range, the difference between electrical threshold of hearing, (T) and maximum comfort (C) levels and can be used to predict ultimate behavioral maximum comfort levels. In acoustically elicited stapedius reflexes a saturation of impedance amplitude can be registered at approximately 110 dB, which is 90% of the dynamic range. Assuming a similar relationship for the electrically elicited stapedius reflex there would be two values within the dynamic range which could be used for extrapolation of the threshold level. In the present study, the electrically elicited stapedius reflex was examined in 16 deaf patients who had received 22-channel Clark/NUCLEUS cochlear implants. Using an apical, a medial and a basal electrode pair, different stimulation positions within the cochlea were tested. The contralateral reflexes could be elicited in 11 patients (69%). A saturation of the reflex amplitude was recordable in 10 subjects, at least in one of the electrode pairs. The reflex saturation in all cases was located close to the uncomfortable loudness level within the subjects' dynamic ranges (at 95% dynamic). This finding is comparable to acoustic matter. As a result, these data together with reflex threshold data suggest a means for predicting to predict the threshold levels.


[Evaluation of frequency selectivity from psychoacoustic tuning curves]. Psychoacoustic tuning curves (PTC) can be regarded as filter curves, whereas their forms represent hair cell activity. Different influences--for example, noise, toxins, pharmacological causes and age--can change the PTC as a consequence of changed frequency selectivity without indication of deterioration in the audiogram. The objective of this investigation was to determine the visually perceivable change in the PTC as a quantifiable result. In so doing, the PTC was transformed into a hyperbola characterized by a parameter Q5. An example demonstrates the temporal change of Q5 under the influence of pharmacological drugs.


[Long-term manifestations of laryngeal sarcoidosis]. We report the medical history of a 19 year old female patient with isolated laryngeal sarcoidosis, who was followed for 12 years. It illustrates the typical course of the disease with remissions and relapses until the inflammation is "burnt out." Although the laryngoscopic findings of pale-red swollen supraglottic structures are pathognomonic, diagnosis is rarely assumed at first sight. Long-term administration of cortisone in low dosage is the treatment of choice. Acute exacerbations with increasing airway obstruction may occur at any time, although in general a tracheotomy can be avoided because high-dose cortisone is highly effective. Over the years, the granulomatous character of the inflammation turns into a chronic non-specific one, while the laryngoscopic aspect hardly changed. Once the sarcoidosis is burnt out, the danger of an acute exacerbation diminishes.


[Cervical lymph node metastasis as a primary manifestation of esthesioneuroblastoma]. A 51-year-old male patient presented with right-sided swelling of the neck and a 2-year history of decreasing olfaction that had culminated in complete anosmia. CT and MRI showed a calcified ethmoid tumor and destruction of the lamina cribrosa extending into the anterior fossa and frontal lobes. Contrast material demonstrated marked enhancement on the CT and MRI. Bilateral angiography of the external and internal carotid arteries failed to show tumor vascularity typical for an esthesioneuroblastoma but rendered an olfactory meningioma unlikely. Histological findings of cervical lymph nodes removed during neck dissection showed infiltration by an esthesioneuroblastoma (Kadish C classification). Tumor calcifications in these neoplasms are generally well seen on CT and--while not specific--may suggest the diagnosis. CT and MRI are the most sensitive methods of demonstrating local tumor growth, metastasis and bone destruction.


[Cicatricial mucous membrane pemphigoid with laryngeal involvement. Case report and review of the literature]. Benign mucous membrane pemphigoid (BMMP) is characterized by immunoglobulin deposits along the basal zone of the skin and mucous membranes, leading to blistering erosions of the involved regions. We report the case history of a 72-year old woman, in whom a cicatricial, supraglottic stenosis caused increasing dyspnea. Through immunohistochemical analysis the diagnosis of BMMP was confirmed. Therapy with cyclophosphamide and steroids led to a remission. Clinical, diagnostic and therapeutic aspects of this laryngologic-dermatologic disease are presented and discussed in the context of the available literature.


[Initial manifestation of localized myasthenia gravis as a differential diagnosis to foramen jugulare syndrome]. The jugular foramen syndrome results in pareses of cranial nerves IX, X and XI and is usually caused by localized pathology of the skull base and/or brainstem through tumors or rheological disorders. As demonstrated in the case reported a systemic neurological illness such as myasthenia gravis should be considered if MRI, CT scan and DSA show no pathology.


Biochemical basis of mupirocin resistance in strains of Staphylococcus aureus. Twenty one strains of Staphylococcus aureus, of varying resistance to mupirocin, were examined in order to determine the mechanism of resistance to this antibiotic; six of these strains were mupirocin sensitive (MIC 0.12-1.0 mg/L) nine moderately resistant strains (MIC 8-256 mg/L) and six highly resistant strains (MIC > 2048 mg/L). Mupirocin showed a time-dependent inhibition of the target enzyme, isoleucyl-tRNA synthetase (IRS); incubation of the antibiotic with this enzyme before adding the substrates markedly increased inhibition in sensitive strains. The IRS I50 values (the antibiotic concentrations which cause a 50% decrease in enzyme activity) correlated well with the MIC values for each strain (P < 0.01). The mean I50 value for sensitive strains was 3.3 x 10(-2) mg/L, in moderately resistant strains it was 1.3 x 10(-1) mg/L and in highly resistant strains it was 7.5 mg/L. No degradation of mupirocin could be detected during extended incubation of the antibiotic with cell free extracts from four resistant S. aureus strains. We conclude that the production of a modified IRS enzyme is the major cause of mupirocin resistance in the strains studied.


The influence of salt concentration on the detection of methicillin resistance in coagulase-negative staphylococci. The detection of methicillin resistance by the breakpoint method was examined using three different media containing varying quantities of added salt and 4 mg/L methicillin or 1 mg/L oxacillin. Three hundred clinical isolates of eight species of coagulase-negative staphylococci were tested. In 68 strains methicillin resistance was expressed only at certain salt concentrations and four distinct susceptibility phenotypes were observed. A correlation between the susceptibility phenotype and the species of the isolate was found. Testing on Columbia agar (CA) containing 4 mg/L methicillin with 0% and 4% added salt was required to detect resistance in all 68 strains. Resistance was detected less frequently using Balanced Sensitivity Test (BST) agar or Diagnostic Sensitivity Test (DST) agar containing methicillin or CA, BST or DST agar containing oxacillin. Increased production of beta-lactamase was shown to be an unlikely cause of MR in these strains. Disc sensitivity tests were performed on the 68 strains using five different media. Columbia agar gave optimum results as the other media gave enhanced zones of inhibition for some isolates. Further tests were performed on CA containing varying salt concentrations using both oxacillin and methicillin discs. A close relationship between the staphylococcal species, and the influence of increasing salt concentration on zone size was found. Discrepancies were noted between results obtained by breakpoint and the results obtained with methicillin discs particularly with Staphylococcus simulans and some Staphylococcus epidermidis strains. Results obtained with oxacillin discs more closely correlated with those obtained by breakpoint, but only when disc tests were performed on media with low and high salt content. To identify methicillin resistance in strains of CNS by disc tests, the use of Columbia agar with 0% and 5% added salt and oxacillin discs is recommended.


2-Heptyl-4-hydroxyquinoline N-oxide, an antistaphylococcal agent produced by Pseudomonas aeruginosa. Clinical isolates of Pseudomonas aeruginosa produce low molecular weight, hydrophobic substances which inhibit the growth of Staphylococcus aureus and other Gram-positive organisms. The active substances have been purified from a culture of P. aeruginosa and characterized as a mixture of 2-heptyl-4-hydroxyquinoline N-oxide and its homologues. The alkyl-hydroxyquinolines (derived through reduction of the N-oxide) were also produced by P. aeruginosa cultures but, in general, were less active against S. aureus. 2-Heptyl-4-hydroxyquinoline was identified in a sample of human bronchial secretions from a patient with cystic fibrosis who was heavily colonized with P. aeruginosa. Production of antibacterial alkyl-hydroxyquinoline N-oxides in human lung may explain the observation that the presence of P. aeruginosa in the sputum of patients with cystic fibrosis is correlated with the absence of S. aureus.


Comparative in-vitro activities of newer cephalosporins cefclidin, cefepime, and cefpirome against ceftazidime- or imipenem-resistant Pseudomonas aeruginosa. Three hundred and thirty-four recent clinical isolates of Pseudomonas aeruginosa were examined for susceptibility to cefclidin, cefepime, and cefpirome. Of these strains, 28.7% were resistant to ceftazidime, and 23.4% were resistant to imipenem. About half of those resistant to ceftazidime were also resistant to imipemem. Although 37.4% and 59.6% of the isolates were resistant to cefepime and cefpirome respectively, and most or all ceftazidime-resistant strains showed resistance to cefepime and cefpirome, only 3.9% were resistant to cefclidin. Ceftazidime-resistant, but cefclidin-susceptible, P. aeruginosa produced high levels of chromosomal cephalosporinases. Of the compounds tested, cefclidin showed the lowest affinity for these enzymes, suggesting that its high activity against P. aeruginosa resistant to several beta-lactams was mainly due to its high resistance to enzymatic hydrolysis. Thirteen strains resistant to cefclidin were also resistant to both cefepime and cefpirome, and eight and three of these strains were resistant to ceftazidime and imipenem, respectively. A penicillinase, which hydrolyzed cefclidin, was detected in the cefclidin-resistant P. aeruginosa, which was similar to the OXA-1 beta-lactamase.


The in-vitro bactericidal activities of combinations of antimicrobial agents against clinical isolates of Mycobacterium avium-intracellulare. The in-vitro activities of five antimicrobial agents (rifabutin, clarithromycin, ethambutol, ciprofloxacin and amikacin), alone and in combination, were evaluated against 21 strains of Mycobacterium avium-intracellulare isolated from patients with AIDS. The combined activities of these agents were studied on solid medium by a full chequerboard method. Synergy was demonstrated most frequently (28-71% of isolates) with those combinations that included ethambutol. In killing curve experiments where double and triple combinations of agents were tested against two of the strains, 99% kill was achieved in seven days at concentrations well below those that are attainable in serum. However, an additive rather than a synergic effect was seen in most instances. Although ciprofloxacin alone had the greatest bactericidal activity against these two strains, its activity was antagonized in the presence of rifabutin; this antagonism became inapparent when a third agent was added. Demonstration of bactericidal activity in broth culture may be more relevant than the results of susceptibility testing on solid medium when choosing antimicrobial therapy for patients with this infection.


High-level aminoglycoside resistance among enterococci and group A streptococci. The occurrence of high-level aminoglycoside resistance (HLAmR) was determined for 73 enterococci and 54 group A streptococci by the high-load disc method, tube macrodilution and the polymerase chain reaction (PCR). The PCR method revealed the presence of genes coding for aminoglycoside-3'-O-phosphoryltransferase-III (APH(3')-III), aminoglycoside-6'-N-acetyltransferase/2''-O-phosphoryltransferase (AAC(6')/APH(2'')), or both, in 20.6%, 9.6% and 4.1% of the enterococci, respectively. The prevalence of HLAmR to at least one aminoglycoside among local enterococci was 37% (27/73). Only one of 54 Streptococcus pyogenes isolates produced APH(3')-III and exhibited high-level resistance to kanamycin and streptomycin. In general, the three methods yielded comparable results, with only three discrepancies among the 127 isolates examined. High-load disc screening and tube macrodilution proved to be practical, reliable and reproducible, and thus suitable for routine screening. Of 20 Enterococcus faecalis strains tested, all were penicillin-tolerant. Only one of seven penicillin-tolerant S. pyogenes strains was HLAmR. No association between the two forms of resistance was found.


Prevalence of resistance to beta-lactam antibiotics in Escherichia coli isolated from blood from 1969-1991. MICs of beta-lactam antibiotics were determined for blood culture isolates of Escherichia coli from patients in St. Thomas' Hospital, London between 1969 and 1991. There was correlation between MICs of carbenicillin and those of amoxycillin (Kendall's coefficient of rank correlation, tau = 0.67), mezlocillin (tau = 0.73), cephaloridine (tau = 0.64) and amoxycillin/clavulanic acid (tau = 0.72), but less correlation between MICs of carbenicillin and cefuroxime (tau = 0.31). During the two decades, the geometric mean MICs increased for carbenicillin (6.6-fold increase in mean MIC), mezlocillin (3.4-fold increase in mean MIC), cephaloridine (two-fold increase in mean MIC) and, to a smaller extent, amoxycillin/clavulanic acid (1.2-fold increase in mean MIC), but not for cefuroxime. These changes were the result of increases in the proportion of isolates that were resistant to carbenicillin and not of changes in the phenotype of carbenicillin-resistant isolates.


Co-trimoxazole impairs colonization resistance in healthy volunteers. The influence of co-trimoxazole on colonization resistance of the bowel was investigated in six healthy volunteers, by measuring the numbers of indigenous aerobic flora and of a co-trimoxazole resistant challenge strain of Klebsiella pneumoniae. Impairment of colonization resistance of the bowel was shown by a significant increase in the numbers of yeasts in the faeces of five of six volunteers, by a significant increase in the numbers of Gram-negative bacilli in the faeces of two of six volunteers, and by facilitation of colonization of the bowel by the challenge strain in all volunteers. Impairment of colonization resistance of the mouth was shown by the development of glossitis caused by Candida albicans in two volunteers, and by a significant increase in the numbers of yeasts in mouth washings from four volunteers. It is concluded that co-trimoxazole impairs colonization resistance of the gastro-intestinal tract.


Ecological effects of short-term ciprofloxacin treatment of travellers' diarrhoea. Forty-two subjects travelling to Mexico for 11 days were enrolled in a randomized, double-blind, placebo-controlled trial comparing ciprofloxacin 250 mg twice daily for three days or placebo for treatment of travellers' diarrhoea. Seventeen (41%) subjects were randomized to treatment. By the last treatment day, all seven evaluable subjects in the ciprofloxacin group, and three of eight evaluable subjects in the placebo group were cured (P = 0.04). The mean time to cure was 26 h for ciprofloxacin and 60 h for placebo-treated patients (P = 0.03). Faecal specimen were collected pre-travel, after four days in Mexico, 48 h post-travel and four weeks post-travel. Potentially pathogenic Escherichia coli strains carrying diarrhoeagenic virulence genes were detected by DNA hybridization tests, during or after travel, in 41% of treated and 31% of asymptomatic travellers. Travel, irrespective of diarrhoea and type of treatment, had a minor impact on the aerobic and anaerobic microflora. In travellers with ongoing diarrhoea, a suppression of the numbers of anaerobic bacteria was found, but the microflora was otherwise virtually unaffected. Significantly increased frequencies of E. coli resistant to ampicillin, doxycycline, chloramphenicol and co-trimoxazole were found during and after travel in all categories of travellers, though more frequently in subjects who experienced diarrhoea. The susceptibility of Bacteroides spp. remained unchanged. The sensitivity of E. coli to ciprofloxacin was not affected by travel, except in four ciprofloxacin-treated subjects who acquired multiresistant E. coli with ciprofloxacin MICs of > or = 0.125 mg/L post-travel. Bacteroides strains with MICs of > or = 64 mg/L were isolated post-travel from four ciprofloxacin-treated patients, and from one of the other 34 travellers not treated with ciprofloxacin.


Randomized prospective study comparing two dosage regimens of ciprofloxacin for the treatment of typhoid fever. Sixty-two patients with blood culture-proven typhoid fever were randomly assigned to receive either 500 or 750 mg of ciprofloxacin orally, twice daily for 7 days or for two days following defervescence, whichever was greater. Thirty-four and 28 patients received 500 mg and 750 mg respectively. Strains of Salmonella typhi resistant to ampicillin, chloramphenicol and co-trimoxazole were isolated from the blood of 27 patients (43.5%). No resistance to ciprofloxacin was encountered. Both regimens were equally effective; fever subsided in mean times of 4.9 +/- 1.7 days in the 500 mg group and 5.2 +/- 2.2 days in the 750 mg group (P = 0.54). All patients were cured, although one patient in the 750 mg group experienced a presumed relapse two months following completion of therapy. Ciprofloxacin administered for 7-10 days was adequate treatment for 57 of the 62 patients (92%); only five patients required therapy for more than 10 days. Patients with pretreatment symptoms of > or = 10 days duration defervesced in a mean of 5.7 +/- 2.3 days compared with 4.5 +/- 1.3 days (P = 0.01) for those with symptoms of shorter duration. We conclude that 500 mg of ciprofloxacin taken orally twice daily is adequate treatment for typhoid fever.


Relationship between cariogenic events and salivary tests in boys and girls: oral examination. For boys and girls several salivary tests have been correlated with the following early cariogenic processes developing simultaneously in dental enamel: initiation, regression, stabilization and progression. These events were observed clinically during three consecutive intervals. Only correlations, significant during at least two random intervals were discussed. The Snyder test determined at 24 hours was significantly positively correlated with most events confined to the enamel surfaces and only the Snyder test determined at 48 hours in stimulated saliva appeared to be significantly positively related with deeper processes such as progression. In addition, the mineral composition of Ca2+, P and Mg2+ in saliva was significantly related to cariogenic events in the enamel surfaces of girls, and its viscosity for boys. Finally, and most interesting from a clinical point of view, was the fact that caries progression was negatively related with P concentrations in both unstimulated and stimulated saliva for girls. For boys a negative correlation was found between caries progression and flow of stimulated saliva.


The effects of NaF, alpha-C12DMEAHF and alpha-C12DMEAHCl on caries development in dentine in situ. Using histological techniques it was possible to demonstrate that during in situ caries development in bovine dentine, the demineralization process preceded the emergence and changes in the organic matrices. In addition, these data demonstrated as that 0.006% F- given either as the quaternary ammonium compound or NaF completely prevented demineralization by acting primarily on the dentine mineral. Inhibition by the quaternary ammonium compound alone was incomplete probably through repression of acid production by micro-organisms normally resident in the saliva.


[The adhesion of Actinobacillus actinomycetemcomitans to oral epithelial cells]. Adherence is a major pathogenicity factor for many bacteria. The aim of this study was to measure the adherence potential of Actinobacillus actinomycetemcomitans (A.a.) for buccal epithelial cells (BEC). In the second part of the study, the inhibitory potential of saliva on adherence between A.a. and BEC was tested. Saliva specimens were obtained from three groups of subjects: a group of normal subjects (NS), a group of subject with localized juvenile periodontitis (LJPS) and a group of subjects with adult periodontitis (APS). Clinical strains of A.a. showed a major adherence potential for BEC (25.5 A.a./BEC). In contrast, reference strains of bacteria appeared to possess a much lower potential for adherence (12.6 A.a./BEC). Saliva samples taken from from the LJPS and APS group had a high inhibitory adherence potential, since in each of these groups a reduction of 60.9% and 66.7% respectively, was observed in the number of bacteria adhering to BEC.


Acid resistance of human enamel by brushing with and without abrasive dentifrice. Daily brushing with and without abrasive dentifrice pieces of was performed on the ground surfaces of human enamel attached to resin plates which were exposed to the oral cavities of 4 subjects for 8 weeks. The difference in acid resistance between a pair of enamel pieces obtained from the same tooth was examined with atomic absorption spectrometry. After etching with a lactate buffer solution at pH 4.5, the amount of Ca dissolved from the enamel in each pair by brushing without dentifrice was significantly lower than that when brushing with an by abrasive paste. Under SEM, the brushing with paste caused prism structures to appear clearly on the enamel surface, while brushing without dentifrice caused a nonbacterial organic film, i.e., salivary pellicle, to cover the surface. These results indicate that the pellicle is protected by mineral deposits when brushing without dentifrice but brushing with an abrasive paste tears off the unmineralized pellicle. Brushing without dentifrice induces a stronger resistance to acid on the enamel surface.


Chromatographic determination of vitamins in foods. Chromatographic methods for the determination of water- and fat-soluble vitamins in foods are reviewed. For each vitamin, sample preparation, detection problems and chromatographic conditions are presented and discussed. High-performance liquid chromatography (HPLC) is becoming a standard method in vitamin assay, especially for routine work. HPLC systems can be automated using in-line solid-phase extraction and column switchings, resulting in very sensitive methods, even when simple UV detection is employed.


Advances in planar chromatography for the separation of food lipids. A survey of the advances in planar chromatography for the separation of food lipids is presented. Techniques of planar chromatography [densitometry, preparative thin-layer chromatography (TLC) and TLC with flame ionization detection, etc.] together with applications from the areas of dairy, marine and plant lipids are discussed. Additives such as lecithins (emulsifying agents) are also considered.


Chromatographic analysis of antibiotic materials in food. The monitoring of food materials for antibiotic residues is an area of increasing concern and importance due to the potential impact on human health. Large-scale screening applications require methods that are rapid, accurate, provide low detection limits and are free from interference. The problem is further complicated by the wide range of chemical functionalities and modes of operation exhibited by the antibiotic materials of physiological significance in use today. As demonstrated, chromatographic methods provide many of the advantages necessary for screening applications. Judicious choice of sample preparation method, separation mode and detection strategy can provide significant immunity from problems associated with the food matrix. Gas chromatography can provide extremely high separation efficiencies, however, only a limited number of antibiotic compounds are inherently volatile enough for direct analysis by gas chromatography. Derivatization to enhance the volatility of the antibiotic is one approach to overcome this limitation. Among the methods available, reversed-phase high-performance liquid chromatography is used extensively for the analysis of many antibiotic systems as it does not require derivatization and it combines relatively high separation efficiencies with low detection limits. The diverse group of properties exhibited by the antibiotic materials in use today suggests that the choice of detection strategy is a key component in the successful development of an analysis technique. Derivatization of the antibiotic material is frequently used to add either a fluorogenic of chromogenic moiety to the antibiotic compound to enhance detection. Derivatization procedures suffer from several limitations which are problematic when making measurements in complicated food matrices. Among the different detection modes utilized for antibiotic analysis, polarimetric detection has the potential to provide extremely selective detection of most antibiotic materials, and this selective response can minimize many of the constraints placed upon the separation system by the sample matrix. Although many of the separation modes used for antibiotic analysis are well developed, separations based on capillary electrophoretic methods have much potential in the field of antibiotic analysis. Future investigations are needed to extend the generality of these techniques and expand their use into the field of food analysis.


Chromatographic methods of analysis for penicillins in food-animal tissues and their significance in regulatory programs for residue reduction and avoidance. Chromatographic methods for penicillin analysis in animal tissues play a significant role in the regulation of the use of these drugs in livestock production. Regulatory agencies rely on data generated from these methods to establish withdrawal times and to determine whether presumptive positive tissue samples from slaughtered animals intended for human consumption contain violative levels of penicillins to necessitate regulatory action. The need to develop sensitive, accurate, and reliable methods to support regulatory programs is examined together with emerging techniques that could be taken advantage of to improve the sensitivity and usefulness of current chromatographic methods for tomorrow's regulatory agency.


Chromatographic methods for tetracycline analysis in foods. The tetracyclines have served for decades as an important class of antibiotics in food animal health and production. As such, they have also been a source of concern for residue monitoring authorities around the world. In response to this concern a number of microbial inhibition, immunoassay and bacterial receptor methods have evolved for the detection of this class of compounds in various foods of animal origin. However, these methods often lack specificity and are subject to false positive and false negative results. For these reasons a number of chromatographic methods for the separation and determination of the tetracyclines isolated from foods have been developed that are capable of identifying and quantifying individual tetracycline drugs. We present here an overview of tetracycline analytical methods, including microbial inhibition, immunoassay and receptor technologies for detection, techniques for isolation from food matrices, and thin-layer chromatographic, high-performance liquid chromatographic, gas chromatographic and mass spectrometric procedures for determination of this class of compounds. A discussion of the variables involved in such methodology and a review of method criteria are offered.


Thin-layer chromatography-flame ionization detection Iatroscan system. The thin-layer chromatography-flame ionization detection (TLC-FID) Iatroscan system is a technique which is still being evolved. Quantification with the TLC-FID system relies heavily on the accurate setting up and calibration of the instrument. An appreciation of the factors that influence the analysis can eliminate significant errors. At least a few of the numerous operating variables need to be fixed to obtain coherent results from different laboratories. Hydrogenation of the sample is recommended in order to improve quantification with the Iatroscan system. The improved reproducibility obtained with automatic sample spotters compared with manual spotting indicates that autosampling is highly advisable.


Chromatographic analysis of cis/trans carotenoid isomers. Cis/trans configurations of carotenoids are known to effect the biochemistry of carotenoids in certain situations. Methodology for separating carotenoid cis/trans isomers is of importance to nutritionists and food scientists because cis isomers of provitamin A carotenoids have lower provitamin A activities than the all-trans form. Traditional food processing and preservation methods, especially thermal treatments, induce the formation of cis isomeric forms. However, many challenges, are apparent for identifying and analyzing cis/trans isomers present in foods and other biological tissues. The development of current chromatographic methods for the separation of carotenoid cis/trans isomers is reviewed. For the separation of beta-carotene isomers, most procedures employ either Ca(OH)2 or Vydac C18 columns. In general, polymeric C18 columns allow for the detection of cis carotenes, while monomeric C18 columns provide for some separation of certain xanthophylls. The main cis isomers detected in foods are the 13-cis and 9-cis forms, although other forms have also been found (mainly 15-cis and various di-cis isomers). More studies involving the metabolism and physiological consequences of cis/trans isomers in the diet are needed. However, due to limitations in current techniques, further method development in the area of separation, detection and quantitation of cis/trans carotenoid isomers will be required.


Chromatographic methods for the analysis of heterocyclic amine food mutagens/carcinogens. A series of potent heterocyclic amines that are mutagenic and carcinogenic have been discovered that are formed in some heated foods, most notably, meats derived from muscle. Determining the heterocyclic amine content in foods and food products is required for toxicological research, industry quality control, and possibly in the future, regulatory control. The contents of food needs to be determined using reliable analytical techniques. Since heterocyclic amines are present in foods at ng/g levels, a variety of liquid-liquid or solid-phase purification techniques are required, followed by gas or high-performance liquid chromatography. Peak detection has been successful using UV, fluorescence, and mass spectrometric detection, and biological activity using the Ames/Salmonella test. The low levels present require that chromatographic efficiency, and both detector sensitivity and selectivity be optimized. The cartridge solid-phase extraction and high-performance liquid chromatography method have been used to measure the known food-derived heterocyclic amines for several types of food, and to the authors knowledge, this is the only method undergoing intralaboratory comparison and validation. Our analysis of the literature shows that chromatographic analysis of the heterocyclic amines by high-performance liquid chromatography or gas chromatography (with derivatization) is satisfactory for heterocyclic amine analysis in foods although the methods are just now being optimized for routine use. The biggest improvements in speed and accuracy will probably come from improved extraction methods as analysis of complex food samples for heterocyclic amines will always be a challenge.


Chromatography of tea constituents.

Chromatography of tea constituents. Modern chromatographic techniques such as high-performance liquid chromatography are currently the most helpful approach to the routine analysis of and research of non-volatile tea constituents. Using these techniques some errors in the more classical analytical techniques could be detected. Unfortunately, some of these methods of analysis are still in widespread use, even as official methods. However, knowledge of especially the polyphenols in tea is still lacking, and for many of the minor polyphenols no chromatographic methods for the determination exist.


Sample preparation for chromatographic analysis of food. Sampling, homogenisation and sample preparation prior to chromatographic injection of food analytes are designed to enhance accuracy and precision. The reduction of inherent errors introduced by these steps requires the analyst's attention as a matter of course. Methods and examples of minimising errors in each step are reviewed.


Analysis of organic micropollutants in the lipid fraction of foodstuffs. An overview is given of current techniques for the analysis of organic micropollutants that accumulate in the fatty fraction of foodstuffs, such as pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polychlorinated dibenzodioxins and polychlorinated dibenzofurans. Isolation and clean-up are considered to be of great importance in the field of residue analysis. In general, problems are related to the low levels of the individual compounds at which they usually occur and the complexity of extraction and clean-up procedures for isolating and separating analytes from matrix components and other contaminants. Therefore, special attention is focused on sample pretreatment and on coupled chromatographic techniques, showing developments towards multi-residue methods, miniaturization and automation of analytical procedures. Coupling of chromatographic techniques with spectroscopic techniques is also considered as an important tool for identification and confirmation purposes.


Determination of aflatoxins in food products by chromatography. Several chromatographic methods for the determination of aflatoxins in agricultural and food products are reviewed. During the past two decades, identification and determination of aflatoxins were done by thin-layer chromatography (TLC) because it was easy, fast and inexpensive. However, high-performance liquid chromatography (HPLC) using fluorescence detection is now the method of choice for determining aflatoxins and is also growing in popularity for their identification. The reasons for selecting HPLC over TLC can be summarized as the ability to analyze for a wide variety of compounds, including compounds that are easily degraded by heat, light or air, the ease of adaptation to confirmatory procedures, the potential for automation and the dramatic improvement in instrumentation, including the development of increasingly sensitive fluorescence and electrochemical detectors and short, high-resolution, reversed-phase columns.


Chromatographic methods for the determination of pesticides in foods. Chromatography is the most important technique available to the analyst dealing with the determination of pesticide residues in food, feed and environmental samples. Numerous methods for pesticide residues in foods have been developed in the past few years, and this paper reviews some of the most important procedures. A great variety of chromatographic methods, such as solid-phase extractions, column chromatographic clean-up methods, thin-layer, gas, high-performance liquid and supercritical fluid chromatography, and their coupling with sensitive and selective detection methods are surveyed.


Chromatographic separation of cholesterol in foods. Based on the current literature and on experience gained in the laboratory, a simplified procedure using direct saponification (0.4 M potassium hydroxide in ethanol and heating at 60 degrees C for 1 h) is the most appropriate method for the determination of total cholesterol in foods. Extraction of the unsaponifiable matter with hexane is efficient and no extra clean-up is required before quantification. An internal standard, 5 alpha-cholestane or epicoprostanol, should be added to the sample prior to saponification and, together with reference standards, carried through the entire procedure to ensure accurate results. A significant improvement in cholesterol methodology has been achieved by decreasing the sample size and performing all the sample preparation steps in a single tube. The method has the advantages of elimination of an initial solvent extraction for total lipids and errors resulting from multiple extractions, transfers, filtration and wash steps after saponification. The resulting hexane extract, which contains a variety of sterols and fat soluble vitamins, requires an efficient capillary column for complete resolution of cholesterol from the other compounds present. The development of fused-silica capillary columns using cross-linked and bonded liquid phases has provided high thermal stability, inertness and separation efficiency and, together with automated cold on-column gas chromatographic injection systems, has resulted in reproducible cholesterol determinations in either underivatized or derivatized form. If free cholesterol and its esters need to be determined separately, they are initially extracted with other lipids with chloroform-methanol followed by their separation by column or thin-layer chromatography and subsequently analysed by gas or liquid chromatography. Although capillary gas chromatography offers superior efficiency in separation, the inherent benefits of liquid chromatography makes it a potential alternative. Isotope dilution mass spectrometry has been widely accepted as a reliable analytical method for highly accurate determination of cholesterol in serum and several definitive methods have been reported. The combination of capillary gas chromatography with mass spectrometry has become an excellent approach for the determination of cholesterol in complex mixtures of sterols and tocopherols, providing high resolution with positive identification. When used to determine cholesterol in multi-component foods, spectrophotometric methods have been documented to overestimate significantly the amount of cholesterol owing to the presence of other interfering substances. A re-evaluation of food products should be undertaken using the more specific chromatographic methods to accumulate data that will more accurately reflect the true cholesterol content.


Gas chromatography of fatty acids.

Gas chromatography of fatty acids. Lipids in foods contain a wide variety of fatty acids differing in chain length, degree of unsaturation, position and configuration of double bonds and the presence of special functional groups. Modern capillary gas chromatography offers excellent separation of fatty acids. Fused-silica capillary columns with stationary phases of medium polarity and non-polar methylsilicone stationary phases successfully separate most of the natural fatty acids. Special applications, such as the separation of complex cis-trans fatty acid mixtures and cyclic fatty acids, required particular chromatographic conditions, including the use of very long capillary columns or more polar stationary phases. The derivatization methods for the preparation of fatty acid esters also need to be optimized to obtain accurate quantitative results. This paper reviews the derivatization techniques, capillary columns and stationary phases commonly used in the gas chromatography of fatty acids in food.


Drug residue analysis using immunoaffinity chromatography. The background and applicability of immunoaffinity chromatographic separations and clean-up to drug residue analysis of agricultural commodities is discussed. The uses of antibody specificity for separation and concentration of drug residues are presented. Examples of immunoaffinity chromatography for the determination of residues of (1) nortestosterone and methyl testosterone in swine muscle, urine and bile; (2) chloramphenicol in swine tissue, eggs and milk; (3) clenbuterol in calf urine; (4) zeranol and beta-zearalanolin in calf urine: (5) diethylstilbestrol, dienestrol and hexestrol in calf urine are presented. Further, examples of the successful coupling of immunoaffinity separations with other chromatographic techniques such as gas chromatography and high-performance liquid chromatography are presented.


High-performance liquid chromatographic methods for the determination of sulfonamides in tissue, milk and eggs. In the last decade, significant research has been done to improve the existing high-performance liquid chromatographic (HPLC) methods and also towards developing simple, reliable and sensitive HPLC methods for sulfonamides in meat, milk and eggs. The replacement of solvent extraction with solid-phase extraction or matrix solid-phase dispersion techniques is a step forward. Significant improvements in sensitivity have been achieved. This review concentrates on HPLC methods for the determination of sulfonamides in foods of animal origin published after 1980. The existing methods are critically evaluated and suggestions for future research are made.


Methods for the determination of sulphonamides in meat. Sulphonamides, due to their important antibacterial effects, are widely used in veterinary practice and animal husbandry. Residues arising from administration without observing withdrawal time sufficiently are normally the parent compounds and the N4-acetyl derivatives, the latter being hydrolyzed to the parent compounds only during extraction under acidic conditions. It is therefore quite conceivable that many authors concentrate on determining these metabolites. In the past decade, we have witnessed a considerable increase in new analytical techniques dealing with the determination of sulphonamides. Among these procedures, especially the so-called multimethods using high-performance liquid chromatography--though sometimes including toilsome clean-up steps--can be mentioned. However, current approaches also utilize gas chromatography, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, supercritical fluid chromatography-mass spectrometry, thin-layer chromatography and immunological methods. For most of these techniques, a strong trend towards lowering the level of detectability (down to the sub-ppb range) and improving accuracy and reproducibility can be established.


Phycotoxins in seafood--toxicological and chromatographic aspects. Two typical clinical types of algae-related seafood poisoning have attracted medical and scientific attention: paralytic shellfish poisoning (PSP) and diarrhetic shellfish poisoning (DSP). Therefore, it became necessary to establish methods for the evaluation of possible hazards caused by contamination of seafood with these phycotoxins. Bioassays with mice or rats are the common methods for the determination of the toxin content of seafood. However, biological tests are not completely satisfactory because of a lack of sensitivity and pronounced variations. Additionally, there is growing opposition against animal testing. Therefore, many efforts have been undertaken to determine phycotoxins by chromatographic methods. PSP determination is mainly based on high-performance liquid chromatographic (HPLC) separation by ion-pair chromatography followed by postcolumn oxidation of the underivatized toxins in alkaline solution and fluorescence detection. HPLC methods for the determination of the DSP toxins okadaic acid (OA) and dinophysistoxin-1 (DTX-1) are characterized by precolumn derivatization with 9-anthryldiazomethane (ADAM) and/or 4-bromomethyl-7-methoxycoumarin (Br-Mmc), followed by chromatographic separation of the DSP esters formed and fluorescence detection. The chromatographic methods discussed in this review allow the rapid, sensitive and non-ambiguous determination of individual species of the two most important phycotoxins in seafood, PSP and DSP.


Application of ion chromatography to the determination of inorganic anions in foodstuffs. A review on the applications of ion chromatography (IC) to the determination of inorganic anions in foodstuffs is presented. The anions were commonly determined in food, i.e., SO3(2-), NO3- and NO2-, and to a lesser extent Cl-, Br-, I-, SO4(2-), IO3-, BrO3- and phosphate, are considered. In comparison with standard methods for the determination of anions in food products, chromatographic methods are rapid, sensitive and precise. They also have the advantage of determining several ions simultaneously. The separation may be achieved by conventional IC, by ion interaction chromatography or by ion exclusion chromatography. IC has also been applied to the determination of Br, I, N and S in foods after oxidation or combustion of samples and conversion into anionic forms.


Electrophoresis and chromatography of wheat proteins: available methods, and procedures for statistical evaluation of the data. Analysis of gluten proteins from the wheat grain endosperm has long challenged the analytical chemist. Several hundred unique polypeptides are present, many in large polymers. This complexity, plus useful relationships of composition to genotype and quality, encouraged development and application of electrophoresis and chromatography for gluten analysis. We review the methods of polyacrylamide gel electrophoresis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, isoelectric focusing and high-performance liquid chromatography available for study of wheat proteins. Singly and in combination, they provide rapid, reproducible, high-resolution separations based on size, charge, or surface hydrophobicity. As challenging and important as the analyses themselves, however, is interpretation of data. Subjective evaluation is sometimes possible, but statistical methods such as similarity scores, clustering, principal components, multiple linear regression, and partial least squares now are increasingly used for data analysis. We review the use of these procedures, and precautions necessary to avoid misinterpretation of data. Optimal evaluation of protein analytical data will enhance the value of such analyses in wheat breeding, marketing, and processing.


Chromatographic and electrophoretic methods used for analysis of milk proteins. Current knowledge of milk proteins and their behavior in dairy foods is based on early applications of chromatography and electrophoresis. Electrophoretic identification of the number and genetic variety of milk proteins inaugurated a research effort in which chromatographic techniques were successfully applied to the isolation of each milk protein, thus facilitating the characterization and further study of milk and dairy products. This review focuses on recent applications of chromatography for separations and analysis and on analytical applications of electrophoresis.


Quaternary and subunit structure of Calliphora arylphorin as deduced from electron microscopy, electrophoresis, and sequence similarities with arthropod hemocyanin. Arylphorin was purified from larvae of the blowfly Calliphora vicina and studied in its oligomeric form and after dissociation at pH 9.6 into native subunits. In accordance with earlier literature, it was electrophoretically shown to be a 500 kDa hexamer (1 x 6) consisting of 78 kDa polypeptides (= subunits). Electron micrographs of negatively stained hexamers show a characteristic curvilinear, equilateral triangle of 12 nm in diameter (top view) and a rectangle measuring 10 x 12 nm (side view). Alternatively, particles in the top view orientation exhibit a roughly circular shape 12 nm in diameter. Crossed immunoelectrophoresis revealed the presence of a major subunit type; the nature of a very minor and a third immunologically separated component remains unclear. A novel 2 x 6 arylphorin particle was detected and isolated. It comprises less than 10% of the total arylphorin material and shows a long, narrow interhexamer bridge in the electron microscope. An arylphorin dissociation intermediate identified as a trimer (1/2 x 6) was isolated; its possible quaternary structure is discussed on the basis of electron micrographs. The epitope of monoclonal antibody Ec-7 directed against tarantula (Eurypelma californicum) hemocyanin subunit d and also reactive to Calliphora arylphorin was traced to a highly conserved peptide of 27 amino acids localized in the center of the protein. The primary structure of Calliphora arylphorin as published in our preceding paper (Naumann and Scheller 1991) is compared in detail to the sequences of spider and spiny lobster hemocyanin. This revealed a basic framework of 103 strictly conserved amino acids. Isofunctional exchanges are proposed for another 76 positions. On the basis of these similarities, and the published three-dimensional model of spiny lobster hemocyanin, a detailed model of the quaternary structure of Calliphora arylphorin is presented. A second larval storage protein previously termed protein II was purified from Calliphora hemolymph. It was demonstrated to be a 500 kDa hexamer of 83 kDa subunits. In the electron microscope it shows a cubic view 9 nm in length with a large central hole and a rectangular view (9 x 10 nm) with a large central cavity. A morphologically very similar hemolymph protein was detected in Drosophila melanogaster larvae. From its structural appearance it is uncertain whether protein II belongs to the hemocyanin superfamily or not.


The effect of teratogens on maternal corticosterone levels and cleft incidence in A/J mice. It is unknown whether orofacial clefting, one consequence of teratogenic exposure, results from a direct interaction between the teratogen and the embryonic palate, or indirectly from maternal alterations caused by the teratogen. In the current study pregnant A/J mice were exposed to one of three cleft-inducing agents in order to examine the relationship between drug-induced clefting and the response of maternal plasma corticosterone to drug administration. The agents used, haloperidol (HAL), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), or phenytoin (PHT), were administered in teratogenic doses between 0800 and 0930 on gestational day 10 (GD 10). For corticosterone determinations, mice were dosed on GD 10, and blood was collected at 1, 4, 24, or 48 hr after dosing. For fetal evaluation of cleft lip and/or cleft palate, mice were dosed on GD 10 and killed on GD 18. Phenytoin was the most potent inducer of cleft lip and palate and induced a sustained elevation of plasma corticosterone in maternal animals. The other treatments, in order of decreasing potency to induce clefting and/or cause an elevation of corticosterone in plasma were 2,4,5-T > HAL > controls. Correlations between maternal corticosterone levels and clefting incidence were very high at all time points examined; total exposure (area under the curve) was also highly correlated. A linear relationship between drug-induced increases in maternal corticosterone levels and the incidence of clefting in A/J mice was evident. Based on these findings, we believe that increased maternal corticosterone levels may play a role in orofacial clefting in A/J mice.


Perspectives on holoprosencephaly: Part II. Central nervous system, craniofacial anatomy, syndrome commentary, diagnostic approach, and experimental studies. This paper presents an updated analytic review of the holoprosencephalic disorders. Central nervous system findings and craniofacial anatomy are discussed in depth. Associated anomalies and syndromes are updated with a syndrome commentary that attempts to separate durable syndromes from associated anomalies and spurious entities. The differential diagnosis of various conditions that may simulate the holoprosencephalic disorders is also discussed. Various experimental approaches to holoprosencephaly are reviewed, indicating that holoprosencephaly appears to be both etiologically and pathogenetically heterogeneous.


H-2 haplotype and heterochronic orofacial morphogenesis in congenic mice: consideration as a possible explanation for differential susceptibility to teratogenesis. For over 40 years it has been known that genetically different inbred strains of mice have different degrees of susceptibility to corticosteroid-induced cleft palate. Gene(s) at or near the H-2 region on chromosome 17 have been implicated. One postulated explanation is that the strain difference in susceptibility is not related to differential corticosteroid action, but to differences in normal developmental pattern. Studies have demonstrated significant quantitative differences between inbred strains for a number of growth variables relative to palatal development. It is also known that there are genes at or near the H-2 complex that influence pre- and post-implantation development. Thus, we sought to determine the relationship in H-2 congenic mice between haplotype differences and variation in normal orofacial development. Morphometric analyses of the palatal region in serially sectioned E13 and E17 B10 and B10.A mice were completed. We were able to find some evidence for H-2 haplotype related phenotypic differences, but these differences are less than compelling as an explanation for haplotype-dependent susceptibility differences. A more likely explanation is GR-mediated differential corticosteroid responsiveness and its consequent effects on palatal shelf growth.


Body temperature and metabolic rate during natural hypothermia in endotherms. During daily torpor and hibernation metabolic rate is reduced to a fraction of the euthermic metabolic rate. This reduction is commonly explained by temperature effects on biochemical reactions, as described by Q10 effects or Arrhenius plots. This study shows that the degree of metabolic suppression during hypothermia can alternatively be explained by active downregulation of metabolic rate and thermoregulatory control of heat production. Heat regulation is fully adequate to predict changes in metabolic rate, and Q10 effects are not required to explain the reduction of energy requirements during hibernation and torpor.


Effects of corticosteroids on short-circuit current across the cecum of the domestic fowl, Gallus domesticus. Both avian corticosteroid hormones, aldosterone and corticosterone, increased short-circuit current across the wall of the ceca of the domestic fowl (Gallus domesticus) in vitro. About 80% of this short-circuit current was inhibited by the Na-channel blocking drug amiloride. Corticosterone was about ten times less potent than aldosterone in increasing short-circuit current and it exerted a similar maximal effect. Cortisol (an endogenous corticosteroid hormone in mammals but not birds) was about ten times less potent than corticosterone and this difference appeared to reflect the presence of the 17 alpha-OH group in cortisol. Carbenoxolene, which inhibits 11 beta-hydroxysteroid dehydrogenase, increased the effect of corticosterone. This effect is consistent with inhibition of the metabolism of corticosterone to 11-dehydrocorticosterone. The latter was found to be about 100 times less potent than corticosterone. The effects of both aldosterone and corticosterone (also dexamethasone) were abolished by the mineralocorticoid receptor antagonist spironolactone. The results suggest that corticosterone has an effect similar to aldosterone but in vivo its action may be depressed by the activity of 11 beta-hydroxysteroid dehydrogenase. The sensitivity of the cecal preparations to corticosterone indicates that this hormone could contribute to the regulation of transcecal Na transport (absorption) in vivo.


Capacitance, short-circuit current and osmotic water flow across different regions of the isolated toad skin. The amphibian antidiuretic hormone, arginine vasotocin, stimulated osmotic water flow across isolated skin from the pelvic but not the pectoral skin of the toad, Bufo woodhouseii. Changes in the apical membrane capacitance were not observed for either region of the skin following treatment with arginine vasotocin when there was an osmotic gradient across the tissue. In the absence of an osmotic pressure gradient, the apical membrane capacitance of the pelvic skin increased from 2.8 +/- 0.5 to 3.3 +/- 0.6 microF.cm-2 after treatment with 5 x 10(-8) M arginine vasotocin. Under these conditions, apical membrane capacitance of the pectoral skin was 1.8 +/- 0.1 microF.cm-2 and did not change significantly after arginine vasotocin treatment. The amiloride-sensitive short-circuit current across the pelvic skin was stimulated by arginine vasotocin as was the density of channels in the apical membrane as determined by fluctuation analysis. Values for channel density in the pelvic skin also correlated with apical membrane capacitance and increased from 90 to 273 channels per micron2 of estimated membrane area following arginine vasotocin treatment. In the pectoral skin the stimulation of short-circuit current following arginine vasotocin treatment was small and an increase in channel density could not be demonstrated. The current through single Na+ channels in both regions of the skin did not different either before or after arginine vasotocin treatment.


Ventilatory accommodation of changing oxygen demand in sciurid rodents. Ventilation was measured across a range of O2 consumption rates in four sciurid rodents: Tamias minimus (47 g), Spermophilus lateralis (189 g), S. beecheyi (531 g), and Marmota flaviventris juveniles (1054 g) and adults (2989 g). Maximum thermogenic oxygen consumption was measured for all but adult M. flaviventris. Aerobic scopes (maximum/minimum O2 consumption rates) were 4.6, 3.8, 5.4, and 4.8 in T. minimus, S. lateralis, S. beecheyi, and juvenile M. flaviventris, respectively. Aerobic scope was at least 4.1 in adult M. flaviventris. Ventilatory accommodation of changing O2 consumption rate was qualitatively similar in the four species, with the bulk of accommodation resulting from changes in minute volume. Nevertheless, there were significant differences in the relative importance of frequency, tidal volume, and O2 extraction in accommodation. In all species, frequency and minute volume were strongly correlated to O2 consumption rate. Tidal volume was significantly correlated to O2 consumption rate in T. minimus and S. beecheyi, but not in the other species. Oxygen extraction was not significantly correlated to O2 consumption rate in any species. Analysis of factorial ventilation changes across a standardized 3.8-fold change in O2 consumption rate revealed significant differences among species in frequency and O2 extraction, but not in tidal or minute volume. When compared to a generalized allometry for mammalian resting ventilation, the four sciurid species had consistently lower respiration frequency and higher O2 extraction than predicted, perhaps because the sciurid measurements were made on unrestrained animals. There was no indication that ventilation constrained maximum O2 consumption rate.


The relative importance of photoperiod and temperature as cues for seasonal acclimation of thermoregulation in pouched mice (Saccostomus campestris: Cricetidae) from southern Africa. The effect of short photoperiod and cold on metabolism and thermoregulation was investigated in pouched mice (Saccostomus campestris: Cricetidae) from three localities in southern Africa which experience contrasting climatic conditions. Mice were initially acclimated to long photoperiod (14L: 10D) at 25 degrees C, followed first by a decline in photoperiod (to 10L: 14D) and then by a fall in temperature (to 10 degrees C). Minimum observed metabolic rate (identical to basal metabolic rate) was unaffected by the decline in photoperiod but increased significantly following cold acclimation. Because minimal thermal conductance remained constant throughout the study the increase in minimum observed metabolic rate caused a decline in lower critical temperature to around 26 degrees C. In contrast to minimum observed metabolic rate, regulatory non-shivering thermogenesis improved significantly following the decline in both photoperiod and temperature. However, pouched mice from the warmest locality were significantly less responsive to photoperiod than those from the other two localities whose survival might depend upon their ability to accurately predict seasonal changes in temperature. Neither photoperiod nor temperature had any effect on body mass, yet pouched mice from the most arid locality, where food supply might be unpredictable, were significantly smaller and had lower total energy requirements than those from areas experiencing higher annual rainfall. These results indicate that S. campestris displays considerable geographical variation in energy requirements together with differences in the use of photoperiod as an anticipatory cue for predicting the onset of winter. These differences appear to be related to the availability of energy and the relative severity of climatic conditions in each locality.


A non-organic and non-enzymatic extraction method gives higher yields of genomic DNA from whole-blood samples than do nine other methods tested. We compared ten methods for extraction of DNA from whole blood. Nine methods require incubation with either enzymes or treatment of organic solvents or both. The 'Rapid Method' (RM) (Method 10) avoids the use of organic solvents (phenol/chloroform) and eliminates completely the use of proteinase K. Thus, the time and cost of DNA extraction are reduced significantly. This is accomplished by salting out and precipitation of the cellular proteins in saturated sodium chloride. This method takes less than an hour to completion, without compromising the yield or the quality of DNA. Using RM, we can make DNA from 0.1 ml of whole blood and as little as 0.5 ml of blood yields DNA sufficient to run a few Southern blots. The RM can also be applied to packed cells. The DNA is free of RNA, protein and degrading enzymes. The uncut DNA runs as a typical slow-migrating, high-molecular-weight and undegraded species in an agarose gel. The DNA is suitable for digestion by various restriction endonucleases. This procedure works equally well with fresh blood samples and with those that are stored at 4 degrees C and -70 degrees C. To our knowledge the RM reported here is the safest, fastest and most quantitative and economical method for preparation of DNA from whole blood and cells.


Measurement of pH to quantify urease activity. The rate of change of pH caused by the hydrolysis of urea was measured for urease solutions of 18 different concentrations. Concentrations were converted into an activity, A (measured in IU/cm3), by using a titrimetric method to assay the urease sample. For activities in the range 0.6-38 IU/cm3, A was related to the initial rate of change of pH, (dpH/dt)0, (measured in s-1) by the empirical relationship: A = 549(dpH/dt)0-1423(dpH/dt)2(0). Values of (dpH/dt)0 were sensitive to changes in the urease activity of about 0.6 IU/cm3.


HPLC analysis of hexosamine phosphates in biological samples. Galactosamine is quickly metabolized to galactosamine 1-phosphate in rats treated with this compound. An HPLC method to quantify hexosamine phosphates in biological samples is described, modified from the o-phthaldialdehyde amino acid analysis procedure. o-Phthaldialdehyde derivatives of hexosamines and hexosamine-phosphates can be eluted from a reverse-phase column at different retention times, with a total analysis time of 30 min and without overlapping with free amino acids at physiological concentrations. The standard curves are linear between 1 and 40 nmol. This simple method is more selective and sensitive than previous enzymatic analyses of hexosamine phosphorylation.


Microdetermination of G6PD isoenzyme activity in human erythrocytes by thin-layer PAG-IEF. An improved method of microdetermination of G6PD isoenzyme activity in human erythrocytes was developed by modification of previously reported procedures. The volume of blood samples was reduced from 2 ml to 20 microliters. After hemolysis in 2% Triton X-100 and 0.1% beta-mercaptoethanol, the samples were subjected to centrifugation and thin-layer isoelectric focusing in polyacrylamide gel (PAG-IEF). By comparison with the original method, excellent resolution was obtained by this more rapid and simple procedure.


Separation of (R)- and (S)-naproxen using micellar chromatography and an alpha 1-acid-glycoprotein column: application for chiral monitoring in human liver microsomes by coupled-column chromatography. A column-switching system for fast determination of (R)- and (S)-naproxen in liver microsomes has been developed. The centrifuged sample was injected directly onto a pre-column with octadecylcoated silica. The retained analytes were then directed to an alpha 1-AGP column using a mobile phase composed of phosphate buffer (pH 6.5), dimethylocytylamine (30 mM) and the nonionic surfactant, Tween 20 (40 g/l). The method gave high absolute recoveries and good repeatabilities: 99.6% (1.7% relative standard deviation) and 94.9% (2.4% R.S.D.) for the (R)- and (S)-naproxen, respectively. The use of a surfactant in combination with an aliphatic amine in the mobile phase involves reduced retention times with retained enantioselectivity. Furthermore, the presence of the surfactant makes it possible to inject biological samples directly into the chromatographic system.


[The ultrastructure of accumulated mitochondria in injuries of demyelinated axons]. The authors ligated the nervus lienalis of the cat, and observed the subsequent accumulation of mitochondria in nonmyelinated axons in close vicinity proximal and distal to the ligature. In enlarged axons they found groups of mostly homogen population of mitochondria with specific morphologic signs. Concerning the mitochondrial ultrastructure authors arranged the mitochondria to three classes and five subclasses. The authors discuss the aim and function of mitochondrial accumulation in the injured nonmyelinated axon. Different directions of mitochondrial group's motion in axons was hypothetically assumed.


Coupling of antibody-binding fragments to solid-phase supports: site-directed binding of F(ab')2 fragments. A method to covalently bind antibody fragments, via their carboxyl termini to solid supports, is presented. The strategy involves: (1) reversibly blocking all the accessible carboxyl groups on the antibody molecule with phenylhydrazine, (2) exposing the carboxyl termini of the fragment by enzymatic digestion with pepsin and (3) subsequently coupling the fragment to an appropriate support. Experiments with an anti-bovine serum albumin monoclonal antibody and C-14 phenylhydrazine revealed that the blocking step was nearly completely reversible with a dilute solution of FeCl3. Radioiodinated blocked F(ab')2 fragments were then coupled to an amino-functionalized Sepharose 4B column, and characterized as to their coupling capacity (mass of protein coupled/ml of bead), and antigen-binding activity. The coupling capacity of the blocked fragments was found to be 12%, half the coupling efficiency of unmodified radioiodinated F(ab')2. The antigen-binding capacity (mol antigen bound per mol antibody coupled) for the blocked F(ab')2, on the other hand, was found to be 1.9, which was approx. 3.5-times greater than for the unmodified F(ab')2. Comparisons with other conventional coupling techniques were also made. These preliminary studies suggest that this technique can provide one with the means to obtain more uniform and active populations of immobilized antibody fragments.


Insulin-like immunoreactivity persists in the spinal cord of streptozotocin-induced diabetic rats. In both saline-injected control and streptozotocin-induced diabetic rats, insulin-like immunoreactivity was localized in the cervical, thoracic, lumbar and sacral segments of the spinal cord. This insulin-like immunoreactivity was consistently localized in the neurons and dendrites from control rats as well as from diabetic rats ranging from 1 month to 12 months after diabetes induction. In the neuronal cell bodies, the reaction product was predominantly localized in the cell nucleus and the proximal and distal dendrites. In the labelled cell nucleus, the reaction product was scattered throughout the cell cytoplasm and nucleoplasm, but not within the nucleolus. The inner and outer nuclear membranes were also labelled. In labelled dendrites, the reaction product was closely associated with the parallel arrays of neurotubules, plasma membranes and synaptic densities. Most of the labelled distal dendrites were postsynaptic to unlabelled axon terminals. A labelled dendrite often formed the central element of a synaptic glomerulus with several unlabelled axon terminals. It is hereby hypothesized that some of the neurons in the spinal cord of the diabetic rat are capable of synthesizing insulin-like substance(s), which appears to be involved in neurotransmission and neuromodulation.


Primary olfactory terminations in the forebrain of amphibia: a comparative study with soybean agglutinin. Ambystoma and Xenopus were used to investigate olfactory terminations in the forebrain by exploiting the selective binding of soybean agglutinin to primary olfactory projections. Lectin binding and tridimensional reconstruction provided new information on the distribution of olfactory glomeruli and on regional and interspecific differences. Ambystoma showed an uniform labelling of all olfactory terminations, which were localized in the rostro-lateral forebrain without obvious segregation of different terminal fields, except at dorsal levels. On the contrary, the binding pattern of Xenopus confirmed the existence of three sets of primary olfactory neurons characterized by clear differences in lectin binding. Selective soybean agglutinin binding and a detailed tridimensional reconstruction provided evidence for the existence of a set of neuronal projections, described for the first time, which terminate in a discrete bilateral region of the forebrain localized below the main olfactory bulb. The presence of three different sets of primary olfactory neurons, the experimental potentials and the possible functional significance of SBA binding sites are discussed.


Axonal and non-axonal immunolocalization of cytosolic aspartate aminotransferase (cAATase), GABA and glutamic acid decarboxylase (GAD) in the rat cochlear nucleus. The localization of both cAATase activity, by histoenzymological method, and the immunoreactivity against cAATase, were investigated in the cochlear nucleus of rats. The immunohistochemical determination of cAATase was carried out using the PAP method, with an antiserum obtained from rabbits immunized with porcine cAATase. It was also studied both the immunolocalization of GABA-like and GAD-like substances. Our observations, with light microscope, revealed weak cAATase activity in the small neurons, and a more intense one in the fibers surrounding neuronal bodies. The large neurons presented a very weakly activity within their neuronal bodies and dendrites, but it was strongly found in granulations that surround the perikaryon and dendrites. cAATase immunoreactivity presents the same distribution as the enzymological activity. In the same way, we have investigated the pattern of distribution of both GABA- and GAD-like substances. Immunolocalization of these substances was similar to that found for cAATase. In the control sections incubated with Gostatin (0.05 mM), cAATase activity was absent. The immunoreactivity was also negative in every immunohistochemical control sections. These facts suggest that aspartate could intervene as a co-neurotransmitter or neuromodulator in the rat cochlear nucleus, and that axonic endings could contain cAATase, GABA and GAD. It was also found immunoreactivity against cAATase, GABA and GAD, in neuronal bodies, dendrites and glial processes, in close association with capillary wall. These observations have led us to suggest the possible co-localization and co-release of both GABA and aspartate from synaptic and non-synaptic sites in the cochlear nucleus.


Ultrastructural and immunocytochemical studies of macrophages in an excitotoxin induced lesion in the rat brain. An epidural application of kainic acid (KA) over the cerebral cortex in rat resulted in an extensive lesion in the ipsilateral cerebral cortex. This procedure elicited an accumulation of a large number of macrophages at the site of lesion covering a period of 4 weeks beginning 4 days after the KA application. The macrophages in the centre of lesion were characterized by abundant cytoplasm containing a variable number of lysosomes and phagosomes. Neurons at the same site were depleted during the period examined. They underwent degeneration following the KA treatment. With the monoclonal antibodies OX-42, OX-18 and OX-6, intense immunoreactivity was observed in these cells at the light and electron microscopic levels. Besides these antibodies, the cells were stained positively with the isolectin Griffonia simplicifolia (GSAI-B4). At the periphery of the lesion, many cells bearing the external morphology of microglia were also intensely stained with the GSAI-B4 and the monoclonal antibodies. It was concluded from this study that neuronal degeneration, caused by the excitotoxin KA, induced the accumulation of macrophages which exhibited CR3 receptors (marked by OX-42), MHC I antigen (marked by OX-18) and MHC Ia (marked by OX-6). The expression of these surface antigens may be related to their active phagocytic activity. The reaction with GSAI-B4 indicates the presence of specific lectin receptors on the macrophages which would serve a similar function. The present lectin histochemistry and immunohistochemical studies suggest that macrophages in the centre of the KA-induced lesion were derived from infiltrated monocytes while those at the periphery originated from the activation of local microglial cells.


Parvalbumin in the medial septum/diagonal band complex of the African green monkey Cercopithecus aethiops. The distribution of the calcium-binding protein Parvalbumin (PV), a marker for a subpopulation of GABAergic neurons, was studied in the septal complex of the African green monkey, Cercopithecus aethiops. PV-immunoreactive neurons were found in relatively small numbers in the medial septum and in large numbers in the nucleus of the diagonal band (BROCA). They were extremely rare in the dorsal and intermediate parts of the lateral septum. PV-immunoreactive neurons in the medial septum and the nucleus of the diagonal band were mostly fusiform when located close to the midline and round to polygonal in more lateral locations. Some perikarya of immunopositive as well as immunonegative cells were covered with immunostained boutons whereas others were not. Our present descriptive data suggest that there are no principal differences in PV-containing neurons in the septal region between non-human primates and rodents which have been analyzed in great detail in previous studies.


[Quantitative analysis of lamina III pyramidal neurons in the parietal cortex of newborns]. The stage of neuronal development in the parietal (postcentral) cortex of human newborns was studied quantitatively in postmortem cases of different gestational (37th or 40th week) and postnatal age (2 hours or 3 weeks). In GOLGI-impregnated tissue obtained by autopsy, layer III pyramidal neurons were investigated. Comparatively, data were collected about dendrite parameters such as dendritic branching, length and spine density. The spine distribution (number and density) at the apical main dendrite, the apical tuft dendrites and in single basal dendritic fields as well, typically for the human layer III pyramidal neuron at the end of the gestational period, is described. Dendritic parameters from basal dendritic fields were compared in the three cases investigated (37th week with 2 hours or with 19 days of survival; 40th week of gestation with 2 days of survival). The large increase in spine number and density, especially in the second and higher orders of dendritic branching was obvious in the 19 days old infant brain. Special pathological aspects of the cases influencing the neuronal development are discussed. By means of a computerized method, quantitative data characterizing the human lamina III pyramidal neuron at the end of gestation are provided.


Development of the visual system of the chick--a review. This article reviews recent and earlier findings that yield the present knowledge about the embryonic development of retina, tectum, and the retinotectal projection in the chick. Data and concepts dealing with cell proliferation, migration, and differentiation, the processes underlying the generation of cytoarchitecture in the nervous system are discussed for the avian visual system. Emphasis is also laid on the presentation of hypotheses and experiments about directed axonal growth along the visual pathway and concerning the mechanisms responsible for the establishment of specific connections between retinal ganglion cells and their central targets. Among the results, the following topics deserve special attention: 1) Investigations of morphogenetic factors in vitro, and the application of recombinant retroviruses in vivo to study cell lineages rendered new insights into the processes of cell determination and differentiation. The evolving picture in this progressing field is discussed. At present, however, the research of retinal and tectal histogenesis is still largely in the state of morphological description. 2) Both systems, retina and optic tectum, develop independently from each other but in corresponding spatio-temporal patterns, which provide that ingrowing retinal axons encounter receptive target tissue at appropriate locations at the time when connections are due to be formed. 3) Possible mechanisms of directed fibre growth are being elucidated by increasing efforts in research devoted to cell surface molecules, neurotrophic, and inhibitory substances, and their receptors. The axons of the primary visual pathway seem to be guided by local cues on glial endfeet and perhaps in the extracellular matrix, but so far, instructive molecules to which functional significance can be assigned have eluded discovery. 4) The question, how the retinotopic projection upon the tectum is created during development, remains still unsolved, although most results point to modified forms of the chemoaffinity hypothesis for its explanation. Sequential maturation and growth, selective fasciculation of orderly entering axons, recognition of positional tectal markers, and functionally controlled refinement may together contribute to the correct retinotectal projection.


Laryngeal papillomatosis.

Laryngeal papillomatosis. The papilloma is one of the most common benign neoplasms of the larynx. Laryngeal papillomatosis is a disease of widespread papilloma formation that most commonly affects the larynx but may involve multiple areas of the aerodigestive tract. Typically, onset of disease during childhood is associated with much more aggressive disease. The etiology of this disease is the human papillomavirus. Diagnosis is often delayed because the symptoms mimic a variety of other diseases. Laryngeal papillomatosis can also be extremely frustrating to treat since the lesions are most often recurrent and aggressive. This article reviews laryngeal papillomatosis, its differential diagnosis, presentation, and classifications as well as its treatment past, present, and future.


Trauma care in Louisiana: problems and possibilities. Trauma is a major national health problem and is the leading cause of death for Americans under the age of 44. Data about the impact of trauma in Louisiana is lacking and there are currently no statewide initiatives for improving trauma care. Louisiana State University Medical Center Hospital in Shreveport (LSUMCH) has recently been licensed and designated by the state as a "primary trauma center." Additionally, the city of Shreveport has enacted a trauma system which preferentially transports major trauma victims to LSUMCH. This is the only such center and system in the state. Based on this experience, it is suggested that development of a network of trauma centers utilizing the resources of the main state teaching hospitals may be a feasible means to upgrade and enhance trauma care in the state.


The use of nonsteroidal anti-inflammatory medications: a therapeutic dilemma. Nonsteroidal anti-inflammatory drugs are the mainstay of therapy for musculoskeletal disorders. Despite being effective for many people they may have serious side effects and their use should be carefully considered in some groups of patients. This article reviews basic information about nonsteroidals including usage, side effects, groups at high risk, and suggestions for decreasing toxicities.


Atraumatic severe streptococcal axillary cellulitis. Axillary streptococcal cellulitis is rare but has been known to clinicians for years. Usually associated with trauma, it may, however, occur in previously healthy individuals who for unknown reasons can be slowly responsive to appropriate antibiotics.


Treatment of urinary incontinence in the elderly. Urinary incontinence affects millions of American men and women. Treatment consists of drug therapy, exercises, mechanical devices, surgery, and injection therapy. This article reviews the advantages and disadvantages of all treatment modalities for this common medical problem.


Raynaud's features in childhood. Clinical, immunological and capillaroscopic study. Raynaud's phenomenon, uncommon in childhood, often heralds connective tissue disorder. Since microvascular abnormalities can be detected at an early stage of the connective tissue disease, especially in scleroderma, a specific diagnosis can be made in patients presenting with Raynaud's phenomenon alone or Raynaud's phenomenon associated with symptoms suggestive of connective tissue disease. Raynaud's phenomenon was studied in 11 consecutive children, 10 girls and 1 boy, ages 6 to 15. One child had a definite diagnosis of cutaneous polyarteritis nodosa. In 6 others connective tissue disease was suspected: 4 had arthritis, 2 has telangiectasia, leg ulcers and antinuclear antibodies. Of the remaining 4, one had hemiplegia and 3 Raynaud's phenomenon only. Oscillometry of the radial artery was reduced in 7 of 9. Decreased capillary resistance was found in 2 of 6, while abrupt thinning in conjunctival vessels was seen in 3 of 7. On nailfold capillaroscopy, reduced vascularity was noted in 5 of 11, dilated capillaries in 4 of 11, tortuousity in 2 of 11, capillary thinning in 1 of 11, capillary spasm in 1 of 11 and normal pattern in 3 of 11. Two patients presenting with Raynaud's phenomenon were found to have "scleroderma-like pattern" on nailfold capillaroscopy. One of them died 2 years later of cardiopulmonary sclerosis, and another developed esophageal stricture and Barrett's esophagus. Neither has sclerodermatous skin. In childhood Raynaud's phenomenon, nailfold capillaroscopy is a non-invasive examination enabling early diagnosis of "systemic scleroderma sine scleroderma".


[Prospective etiologic study of 128 patients with ambulatory dep vein thrombosis]. Etiology of deep vein thrombosis in ambulant patients (DVTA = TVPA in text) varies: cancer, blood disease, infectious focus, dysimmunity syndrome, dysglobulinemia, extrinsic compression, metabolic disorder, anomaly of hemostasis. A prospective study was carried out between June 1988 and September 1989 by angiologists in 5 regions of France to evaluate the diagnostic rentability of an epidemiologic survey and to determine possible distinctive characters of DVTA. The survey was comprised of a questionnaire, a full clinical examination and screening tests: chest x-ray, abdominopelvic ultrasound imaging, a-uro/gynecologic examination, full blood count, serum iron, ferritin, uric acid, triglycerides, cholesterol, protein electrophoresis, antinuclear antibodies, circulating anticoagulant, hemostasis factors and liver function tests. The study included 128 patients, mean age 60 +/- 16 years with a DVTA developing without a previous immobilization. The usual predominance in the left leg was not observed. The etiology was identified in 33 cases, including 20 (15.6%) as a result of the screening tests: anomalies of hemostasis (8), blood diseases (3), dysimmunity syndromes (4), extrinsic compression (3), cancer metastasis (1) and hypertriglyceridemia in a diabetic (1). The screening procedure was of no greater value in the absence of a triggering or predisposing factor, on the contrary. An anomaly of hemostasis was detected more frequently in the presence of local or regional triggering factors in the men (4 out of 4) and in the women on the pill (4 out of 4). The number of cancers discovered following screening (2%) was smaller than that expected according to the literature (10%).(ABSTRACT TRUNCATED AT 250 WORDS)


[Is it possible to cure various disorders of stability or vertigo by surgical correction of tight stenosis of a supra-aortic artery?]. While the efficacy of vertebral arteries revascularisation on the symptoms of vertebrobasilar insufficiency (VBI = IVB in text) is well established, the effect of correction of stenosis of vessels other than the vertebral arteries on stability disorders and vertigo do not appear to have been studied to any extent. Furthermore, vertigo is not considered as specific to VBI. A retrospective study was therefore carried out to determine the outcome in 33 patients with static disorders or vertigo operated upon for a severe stenosis of a brachiocephalic trunk, a carotid artery or a subclavian artery, with or without associated stenosis of a vertebral artery which in all cases had been neglected. Two patients (6%) died during the early stages of this series. Mean duration of follow up was a little longer than 5 years. One month post-operation 61% of the survivors were asymptomatic, all the others reported marked improvement in their symptoms and all had resumed their social life. At a later stage two patients had a clinical relapse associated with new arterial stenosis. Findings in this small series suggest that it is possible to cure or improve patients with stability disorders or vertigo by the surgical correction of a severe stenosis of a supra-aortic artery other than a vertebral artery.


[Ambulatory and hemodynamic treatment of venous insufficiency (CHIVA cure)]. Contrasting with the destructive methods of treating varicose veins, the CHIVA cure (Cure Conservatrice et Hémodynamique de l'Insuffisance Veineuse en Ambulatoire) technique is a conservative and hemodynamic approach of this problem. Based on coherent physiological principles, it proposes rigorous analysis followed by effective correction of the hemodynamic disorders, resulting in lasting benefits on the esthetic, functional and tropic changes associated with varicose veins. The results of the CHIVA technique in several french and european-centers, including over 10,000 procedures performed between 1987 and 1991, confirm the value of the method first described by the author in 1988. They confirm the necessity of respecting the strategic and tactical rules of this new approach and the need for specific theorical and practical training.


[Ambulatory and hemodynamic treatment of varicose veins (CHIVA cure). Revolution or regression]. Ambulatory Hemodynamic Treatment of Varicose veins (CHIVA), owing to duplex scan, is a come back to forgotten method of cutting and ligation of superficial veins which have for a long time given the proof of inefficiency. This method ignores the fundamental problems of venous insufficiency. The long dated superiority of this technic about venous preservation compared with other methods is not demonstrated. The analysis of recurrent varicose veins after surgical treatment shows that the main cause is an inadequate operative technique associated with the evolution of the basic wall failure. CHIVA-cure, starting from the opposite opinion is doing un unbelievable come back to staged ligation expecting better results. The high rate of superficial venous thrombosis and complementary acts on the residual varicose veins, only one year after the primitive surgery, don't augur well of the future.


[Influence of arterial hypertension on diabetic retinopathy]. In the industrialized countries, diabetic retinopathy represents the most frequent cause of blindness during the period of active life. It occurs as two distinct clinical entities: non proliferating retinopathy characterized by dilatation of the retinal capillary bed and alterations in their vascular wall responsible for an increase in permeability, and proliferating retinopathy characterized by the appearance of pre-retinal neovessels secondary to the presence of vast zones of retinal ischemia. Numerous risk factors are implicated in the development of diabetic retinopathy: the primordial factor is the optimal equilibration of blood glucose levels. The primum movens of these diabetic lesions could be intoxication of the pericipets and endothelial cells of the retinal capillaries by an accumulation of sorbitol and fructose in this region. Additionally, the hyperglycemia suppresses the functioning of the retinal blood flow feed back system. An increase in systemic blood pressure will therefore be transmitted directly to the damaged capillary bed. In type II diabetes (NID), worsening of the diabetic retinopathy correlates with elevation of the systolic blood pressure. In type I diabetes (ID), worsening of the diabetic retinopathy correlates with an elevated diastolic blood pressure. A diastolic pressure of less than 74 mm Hg is a statistically significant protective factor against the worsening of type I diabetic retinopathy.


[Arterial hypertension and diabetic nephropathy]. A high incidence of renal lesions is observed in patients with insulin-dependent diabetes. In the early stages of the disease glomerular capillary hemodynamics is altered with, in particular, glomerular hyperfiltration related to several factors: enhanced glomerular capillary flow rate, capillary hypertension and increased filtration area. These hemodynamic changes could affect development of the glomerular microangiopathy: the final outcome of this is the glomerulosclerosis associated with a progressively worsening and ineluctable chronic renal insufficiency. Hypertension, frequent in the early stages, is practically constant when the neuropathy stage has been reached; it is well established that hypertension accelerates the development of glomerular lesions and the progression of the renal impairment. Experimental and clinical studies have clearly demonstrated that antihypertensive treatment slows down the degradation of renal function. All antihypertensive drugs appear to be effective, but converting enzyme inhibitors, by their effects on renal hemodynamics, could play a particular role in the prophylactic treatment of diabetic nephropathy. Determination of urinary excretion of albumin (microalbuminuria), the global evidence of the onset of a nephropathy is useful for the follow up of the renal disease, allows follow up of the renal lesion and evaluation of the efficacy of treatment.


[Compression of the left renal artery by the diaphragm]. Investigation of hypertension in a 21 year old man detected the presence of stenosis of the left renal artery. The arteriographic appearance of this stenosis, associated with the presence of stenosis of the celiac trunk of identical morphology, was suggestive of extrinsic pressure by the diaphragm and excluded endoluminal dilatation. Section of the left diaphragmatic crus released the renal artery and celiac trunk with complete recovery from the hypertension.


[Thrombosis, immunology and drugs].

[Thrombosis, immunology and drugs]. Diagnosis of thrombopenia due to heparin in sometimes false. We present a case with venous thrombosis in whom the suspicion of thrombopenia induced by heparin finally proved to be a quinidine induced lupus. Related to this observation we emphasise the importance of immunological investigation in patient with venous thrombosis.


[Mountain frostbite. A new approach to early prognosis. A study of 1,267 cases]. Regarding an important series of mountain frostbite (1,267 cas), the authors try to explain the physiopathological mechanism. They expose the different methods that make possible nowadays an early prognosis. They set forth the treatment that seems still limited to save what can be spared; and this is valid for severe frostbite, the only ones to put problems. The quick warming up is the keystone of the treatment.


[Lipid balance in an arteritic patient and therapeutic implications]. The pathogenesis of atherosclerosis remains hypothetical, the current vogue of a lipidic origin being now only a working hypothesis. The management of an arteritic patient (for a treating clinician) is that of a case of global atherosclerosis. Screening for lipids: 1) is here of only moderate interest in the close scrutiny of currently recognized risk factors, and 2) should include initially a simple study of total plasma cholesterol (TC) and triglycerides (TG) on two occasions at one month's interval in a reliable laboratory. Therapeutic implications are a function of a global analysis of the patient and not just the values for even sophisticated assays of circulating lipids.


[Theoretical and practical bases of compression]. The pressure applied by rigid or elastic compression of the skin surface of a limb is exerted as a function of two parameters. Pressure applied by an elastic tissue acts according to Laplace's law, varying with the tension of the elastic tissue and the radius of the curve of the area compressed. A rigid dressing acts solely by alternating working and resting pressures. Superficial pressure is transmitted to the extra- and intra-fascial compartments through the intermediary of an increase in tissue pressure. This pressure extension acts on all the compressible structures of the limb. It reduces the caliber of the veins in all compartments, and therefore the total venous blood volume of the limb, and increases the rate of circulatory return. The venous pressure adapts itself to the pressure of the dressing. The action on the vessel wall is seen as an increase in fibrinolytic activity and the proliferation of contractile myocytes. Its principal effect, however, is on vascular-tissue integrity: it diminishes interstitial edema and compacts the connective tissue fibrils, decongests the capillary endothelium and reduces the pericapillary sleeve of mucopolysaccharides. But it increases basal membrane thickness. Too high a pressure provokes collapse of the lymphangions. The rheologic action of the compression results in a decrease in blood viscosity. The effect of the compression is to induce local reabsorption of venous edema, while lymphatic edema is displaced towards the root of the limb to a zone where it may be reabsorbed. All these phenomena are reversible on removal of the compression treatment.


Body mass index and duration of breast feeding: a survival analysis during the first six months of life. The aim was to determine whether excess weight in lactating women is associated with earlier cessation of breastfeeding. The study was to prospective cohort analysis using a community sample of women. Geelong the regional centre of the Barwon Region of Victoria, Australia, in 1984-85. All women who were breast feeding and whose first infant was born between 1 May 1984 and 30 April 1985 were asked to participate. Of these, 739 women participated, a response rate of 81%. Smoking, mother's age and occupation, the time the infant was first put to the breast, and mother's body mass index at one month postpartum all exerted statistically significant independent effects on the duration of breast feeding, assessed using Cox's proportional hazards regression modelling. The strongest effects were for smoking, with an adjusted relative risk for cessation of breast feeding of 2.5 (95% CI 1.9 to 3.1) for 10 cigarettes per day v no smoking, and maternal age, with relative risk of 2.2 (95% CI 1.5 to 3.1) for a 20 year old mother relative to a 30 year old. The relative risk for women with a body mass index above 26 was 1.5 (95% CI 1.1 to 2.0). Excess weight at one month postpartum, as determined by a body mass index above the normal range, was found to be an independent risk factor for early cessation of breast feeding and together with smoking, maternal age, occupation, and the time the infant is first put to the breast can be used to identify, early in the postpartum period, those women most likely to benefit from counselling in order to breast feed their infants successfully.


Leukaemia clusters in Great Britain. 1. Space-time interactions. The aim was to test a large set of childhood leukaemia and lymphoma registrations for the presence of clusters in space and in time. The study was a space-time cluster analysis. England, Wales and Scotland. All registrations for leukaemia and lymphoma between 1966 and 1983 in children aged 0 to 14 years were examined. The records included date and age of registration, sex, diagnosis, and the map reference of the postcode of residence. Of the 9411 registrations, 8888 were suitable for inclusion. There was a statistically significant excess of case pairs occurring jointly within 0.5 km and 60 d of each other: 68 pairs compared with 50.0 expected. The excess was detectable in central England, in the north of England and Scotland, but not in the south west of England. It was concentrated within the age band 4 to 7 years and among the lymphatic leukaemias. Several potential artefacts were considered and excluded, but the possibility remained that clustered detections might be triggered by haematological examinations undertaken for some communicable disease. There was strong evidence of joint spatial-temporal clustering, with an excess of pairs separated by very short time and distance intervals. The causes are probably biological rather than artefactual, but further work will be necessary in order to exclude the latter.