Overregularization in language acquisition. Children extend regular grammatical patterns to irregular words, resulting in overregularizations like comed, often after a period of correct performance ("U-shaped development"). The errors seem paradigmatic of rule use, hence bear on central issues in the psychology of rules: how creative rule application interacts with memorized exceptions in development, how overgeneral rules are unlearned in the absence of parental feedback, and whether cognitive processes involve explicit rules or parallel distributed processing (connectionist) networks. We remedy the lack of quantitative data on overregularization by analyzing 11,521 irregular past tense utterances in the spontaneous speech of 83 children. Our findings are as follows. (1) Overregularization errors are relatively rare (median 2.5% of irregular past tense forms), suggesting that there is no qualitative defect in children's grammars that must be unlearned. (2) Overregularization occurs at a roughly constant low rate from the 2s into the school-age years, affecting most irregular verbs. (3) Although overregularization errors never predominate, one aspect of their purported U-shaped development was confirmed quantitatively: an extended period of correct performance precedes the first error. (4) Overregularization does not correlate with increases in the number or proportion of regular verbs in parental speech, children's speech, or children's vocabularies. Thus, the traditional account in which memory operates before rules cannot be replaced by a connectionist alternative in which a single network displays rotelike or rulelike behavior in response to changes in input statistics. (5) Overregularizations first appear when children begin to mark regular verbs for tense reliably (i.e., when they stop saying Yesterday I walk). (6) The more often a parent uses an irregular form, the less often the child overregularizes it. (7) Verbs are protected from overregularization by similar-sounding irregulars, but they are not attracted to overregularization by similar-sounding regulars, suggesting that irregular patterns are stored in an associative memory with connectionist properties, but that regulars are not. We propose a simple explanation. Children, like adults, mark tense using memory (for irregulars) and an affixation rule that can generate a regular past tense form for any verb. Retrieval of an irregular blocks the rule, but children's memory traces are not strong enough to guarantee perfect retrieval. When retrieval fails, the rule is applied, and overregularization results.


Active muscle length reduction progressively damages soleus in hindlimb-suspended rabbits. This study describes the morphologic changes in rabbit soleus muscle following hindlimb suspension (HS) for 1 to 4 weeks (group A); or following HS with hindfeet passively dorsiflexed, by means of an elastic band, for 1 to 2 weeks (group B). In the latter, elastic band use allowed phasic contractions of foot extensor muscles against resistance and prevented 35% chronic soleus shortening, which occurred in group A animals. In group A, the soleus revealed progressive muscle atrophy and myofibrillar damage. Myofibrils underwent dissolution, muscle regeneration was ineffective, and adipose tissue developed from about 2-week suspension onward. Conversely, passive dorsiflexion of unloaded hindfeet was essential in maintaining mass and structural muscle integrity in the soleus of group B. It is hereby demonstrated that HS-induced soleus damage in the rabbit is progressive, and can be prevented, avoiding long-term shortening of soleus and its phasic unloaded contractions. Soleus sensitivity to unloading conditions, such as HS, tenotomy, and hypogravity, may depend on the particular physiology of this tonic antigravity muscle, engaged mainly in developing long-lasting isometric contractions in a stretched length.


Perioral reflexes in orofacial dyskinesia and spasmodic dysphonia. In order to assess the clinical utility of trigemino-facial reflexes in lower facial muscles, we studied perioral reflexes to mechanical and electrical stimulation in 13 patients with spasmodic dysphonia and orofacial dyskinesia and in 7 healthy subjects. Mechanical stimulation of the upper lip of all patients and electrical stimulation of the infraorbital nerve of patients with orofacial dyskinesia elicited larger perioral reflexes than in controls. In the majority of patients, hyperexcitable perioral reflexes were accompanied by increased gain of the blink reflex. In 4 patients, however, trigemino-facial reflexes were enhanced selectively in either the perioral muscles or orbicularis oculi. Our findings suggest that the quantitative assessment of perioral reflexes may provide information about the excitability of brainstem interneurons in cranial dystonia that is complementary to blink reflex studies.


Immunocytochemical localization of the multicatalytic proteinase (proteasome) in crustacean striated muscles. Multicatalytic proteinase (MCP) is thought to play a central role in the processing and turnover of intracellular proteins in eukaryotic cells. Immunocytochemistry was used to determine the intracellular distribution of the MCP in the claw muscles of the land crab, Gecarcinus lateralis, and the claw and abdominal muscles of the American lobster, Homarus americanus. Cryosections were stained with an affinity-purified polyclonal antibody to lobster MCP that cross-reacted with the land crab enzyme. Two types of staining were observed: a diffuse cytoplasmic staining, and a dense aggregate staining primarily associated with invaginations of the cell membrane. The cytoplasmic staining appeared reticulated in favorable transverse sections due to a preferential localization of MCP to the intermyofibrillar space. The aggregate staining was associated with neither nuclei nor mitochondria, since stains specific for these organelles (Hoechst stain and nicotinamide adenine dinucleotide diaphorase histochemistry, respectively) did not colocalize with the aggregates. Trypsinlike peptidase activities of isolated microsomal and postmicrosomal fractions indicated that less than 1% of the total MCP was associated with the microsomal fraction. Immunoprecipitation of the same fractions confirmed the presence of MCP in the microsomes as well as in the cytosol. These results suggest that the MCP is primarily associated with cytoplasmic components; the aggregate staining may result from the association of the MCP with cellular membrane systems.


Dermatomal somatosensory evoked potentials in the diagnosis of lumbosacral spinal stenosis: comparison with imaging studies. Dermatomal somatosensory evoked potentials (DSEPs) and computerized tomography/magnetic resonance (CT and/or MR) images were retrospectively analyzed to evaluate their relationship in the diagnosis of lumbosacral spinal stenosis (SS). Of 155 patients referred for DSEPs with a clinical suspicion of lumbosacral SS, 58 met the inclusion criteria. DSEP abnormality was defined as: (1) N1 latency absent or greater than 2.5 SD; (2) side-to-side latency difference greater than 2 SD; (3) amplitudes greater than 2 SD below the mean; or (4) amplitude ratio greater than 2 SD. Involvement of two or more DSEP levels by any of the above criteria was labeled multiple root disease (MRD). Involvement of one level was labeled single root disease (SRD). Images were reviewed independently by a neuroradiologist. Results revealed 54 subjects with SS by imaging; 42 had MRD and 8 had SRD by DSEPs. Sensitivity for MRD and SS was 78%, and for MRD plus SRD and SS was 93%.


Treatment of hemifacial spasm with botulinum toxin. The effectiveness of botulinum toxin injections in 11 patients with hemifacial spasm was investigated in a prospective placebo-controlled blinded study. The patients were treated with four sets of injections to various facial muscles, selected by clinical evaluation. Three injections were with graded doses of toxin and one was with placebo. The order of injections was random and unknown to the patients. Results were scored both subjectively by patient assessment of symptoms and objectively by blinded review of videotapes made one month after each injection. Subjective improvement occurred after 79% of injections with botulinum toxin, regardless of dose of toxin. Only 1 patient improved after placebo. Objective improvement was seen after 84% of injections with botulinum toxin. No patient showed objective improvement after placebo injection. The most frequent side effect was facial weakness, seen after 97% of injections of botulinum toxin. Facial bruising (20%), diplopia (13%), ptosis (7%), and various other mild side effects were seen less frequently. Botulinum toxin appears to be an effective and safe method of therapy for hemifacial spasm.


Short segment incremental studies in the evaluation of ulnar neuropathy at the elbow. Conventional electrodiagnosis may localize an ulnar neuropathy to the general region of the elbow. Separating retroepicondylar compression from compression by the humeroulnar aponeurotic arcade from compression by the deep flexorpronator aponeurosis is more difficult. In 35 patients, we compared localization by conventional inching (stimulating stepwise around the elbow searching for focal conduction block or differential slowing) to localization by a more quantitative short segment incremental stimulation (SSIS) technique assessing latency change over consecutive 1 cm segments. Results of percutaneous studies were compared with findings of intraoperative electroneurography. We conclude that SSIS identifies compression levels more accurately than standard inching, and that SSIS and intraoperative electroneurography correlate highly, but not perfectly. Studies confined to a search for conduction block or differential slowing are limited by the low incidence of conduction block in chronic compression neuropathies.


AAEM case report #25: anterior interosseous nerve syndrome. A case study is reported regarding a 57-year-old woman, chose chief complaint was weakness in her thumb that she had noted while gardening. The patient described difficulty pulling weeds out because of an inability to get a firm grip when using the thumb. Physical examination showed weakness of the flexor pollicis longus and flexor digitorum profundus to the index finger. There was no other weakness and no clinical sensory deficit. Electrodiagnostic studies revealed normal median motor and sensory nerve conduction studies with needle examination abnormalities noted only in the flexor pollicis longus, flexor digitorum profundus, and pronator quadratus. The literature on anterior interosseous nerve syndrome (AINS) is reviewed. It is important to differentiate those with idiopathic AINS as part of a neuralgic amyotrophy picture from those with an anatomic cause such as a fibrous band or anomalous muscle. Electrodiagnostic examination can be useful to help make this distinction.


Development of calcitonin-gene-related peptide, chromogranin A, and synaptic vesicle markers in rat motor endplates, studied using immunofluorescence and confocal laser scanning. The presence of calcitonin-gene-related peptide (CGRP) and chromogranin A was investigated in the developing rat (E18-adult) motor system, using immunofluorescence and confocal laser scanning, and compared with synaptic vesicle markers, synaptophysin and synapsin I. In lumbar motor perikarya CGRP-LI and Chr A-LI were present in high intensities in E18 and P1 perikarya in the anterior horn. With increasing age immunoreactivity decreased. Chr A-LI was sparse in the adult. In peroneal endplates, p38-LI and SYN I-LI were present in all stages, including E18. Peptide-LI was very weak or absent in early stages (E18 and P1), but abundant in P8 and P18, especially CGRP-LI, and decreased again in P32 and adult animals. These observations indicate that the peptides have precise functions during certain developmental stages, possibly related to synapse maturation, receptor concentration, and reduction of supernumerary endplates. Both peptides are rapidly transported anterogradely in adult motor axons, and may serve physiological functions also in the adult.


SEPs and CNS magnetic stimulation in syringomyelia. Somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) to transcranial and spinal stimulation from upper and lower limb muscles were elicited in 13 patients with syringomyelia. Seven had an associated Chiari type I anomaly. Diagnosis was confirmed by MRI. In 5 cases, SEPs and MEPs were performed before and after surgical treatment. Prolonged central motor conduction times or absent motor responses in upper or lower limbs were found in most patients. The greatest number of abnormalities was disclosed by measurement of CMCT followed by SEPs after tibial nerve stimulation. Two of 5 cases undergoing surgery improved clinically and showed reduction in CMCT after surgical treatment. Our study shows that MEPs were useful in the evaluation of neurophysiological status in syringomyelia patients, helping to estimate anterolateral spinal cord function.


Binding of malarial circumsporozoite protein to sulfatides [Gal(3-SO4)beta 1-Cer] and cholesterol-3-sulfate and its dependence on disulfide bond formation between cysteines in region II. Region II of the malaria circumsporozoite (CS) protein is highly conserved between the CS proteins of different species of malaria. Amino acid sequences homologous to that of region II are found in thrombospondin, properdin, von Willebrand factor and a few other proteins. We show here that the native CS protein from the rodent parasite Plasmodium berghei, and recombinant Plasmodium vivax and Plasmodium falciparum CS proteins containing region II, but not recombinant proteins lacking region II, specifically bind to sulfatides and cholesterol-3-sulfate. The binding is abolished following reduction and alkylation of the proteins. Region II contains 2 cysteines separated by only 3 amino acids, S(N), V, T, and these are the only cysteines present in our recombinant proteins. Therefore, our findings strongly suggest that the region II cysteines are linked by a disulfide bond forming a small peptide loop. We also present evidence that the recognition of sulfatides, cholesterol-3-sulfate, or other cross-reactive sulfated macromolecules by region II may be required during sporozoite invasion of liver cells. Antibodies to a peptide representing region II react with live sporozoites and with sporozoites fixed with glutaraldehyde, indicating that this region is exposed on the surface of the parasites. Furthermore, we have found that the sulfatide and cholesterol-3-sulfate recognition by the CS proteins, and the invasion of hepatocytes by P. berghei sporozoites, are specifically inhibited by dextran sulfate.


Pyruvate kinase from Trichomonas vaginalis, an allosteric enzyme stimulated by ribose 5-phosphate and glycerate 3-phosphate. Trichomonas vaginalis pyruvate kinase was purified over 1750 fold to a specific activity greater than 100 mumol min-1 (mg protein)-1. The enzyme is a tetramer of M(r) 266,000, consisting of subunits of M(r) 53,000 and 56,000 in equivalent amounts. Its activity was dependent on the presence of magnesium but was not stimulated by potassium or ammonium. The enzyme exhibited positive cooperativity towards phosphoenolpyruvate and was inhibited by inorganic phosphate, which increased the sigmoidicity of the saturation curve for phosphoenolpyruvate without affecting maximal activity. It was heterotropically stimulated by ribose 5-phosphate and glycerate 3-phosphate, not previously known to act on eukaryotic pyruvate kinases, but was unaffected by known effectors of most pyruvate kinases, including fructose 1,6-bisphosphate and fructose 2,6-bisphosphate.


Purification and characterization of a novel sialidase found in procyclic culture forms of Trypanosoma brucei. A membrane-bound sialidase (EC 3.2.1.18) was found in procyclic trypomastigotes of Trypanosoma brucei. The mammalian stage bloodstream form, however, displayed no sialidase activity. This sialidase is an integral surface protein, linked to the membrane via a glycosylphosphatidylinositol anchor. After osmotic lysis and solubilization with Triton CF-54, the enzyme was purified 1900-fold by gel filtration and ion exchange chromatography. Its size, as determined by conventional and high-performance liquid gel chromatography, is 67 kDa. The sialidase is active over a broad pH and temperature range with optima at pH 6.9 and 35 degrees C, respectively. No loss of activity is observed after 4 freeze-thaw cycles. T. brucei sialidase activity is inhibited by N-(4-nitrophenyl)oxamic acid and 2-deoxy-2,3-didehydro-N-acetylneuraminic acid, the latter, however, being less effective. N-Acetylneuraminic acid shows no inhibitory effect, whereas a variety of metal ions are potent inhibitors. The sialidase is activated by di- and tricarboxylic acids, but inhibited by chloride. Relative hydrolysis rates of various sialic acid-containing compounds reveal that de-O-acetylated bovine submandibular gland mucin is the preferred substrate and that alpha(2-3)-linkages are hydrolyzed faster than alpha(2-6)-linkages.


Succinate-dependent metabolism in Trypanosoma cruzi epimastigotes. Trypanosoma cruzi epimastigotes permeabilized with digitonin (65 micrograms (mg protein)-1) to measure mitochondrial respiration were exposed to different substrates. Although none of the NADH-dependent substrates stimulated respiration, succinate supported not only oxygen consumption but also oxidative phosphorylation (respiratory control ratio of 1.9 +/- 0.3) indicating that the mitochondria were coupled. The rate of NADH-dependent oxygen consumption by membrane fractions (9.4 +/- 0.7 nmol min-1 (mg protein)-1) was reduced by 50% upon addition of catalase indicating that the electrons from NADH oxidation reduced oxygen to H2O2. NADH-dependent H2O2 production (16 +/- 1 nmol min-1 (mg protein)-1) was confirmed using cytochrome c peroxidase. This activity was inhibited by fumarate by 70%, suggesting a competition between fumarate and oxygen for the electrons from NADH, probably at the fumarate reductase level. The respiratory chain inhibitor antimycin blocked both respiration by intact cells and succinate-dependent cytochrome c by isolated membranes. No inhibition by antimycin was observed when NADH replaced succinate as an electron donor, indicating that the electrons from NADH oxidation reduced cytochrome c through a different route. Malonate blocked not only succinate-cytochrome c reductase and fumarate reductase, but also intact cell motility. These results suggest that succinate has a central role in the intermediate metabolism of i. cruzi, as it may be used for respiration or excreted to the extracellular space under anaerobic conditions. In addition, 2 potential sources of H2O2 were tentatively identified as: (a) the enzyme fumarate reductase; and (b) a succinate-dependent site, which may be the semiquinone form of Coenzyme Q9, as in mammalian mitochondria.


Molecular characterization of a Dirofilaria immitis cDNA encoding a highly immunoreactive antigen. Dirofilaria immitis, a filarial nematode, is the causative agent of canine and feline heartworm disease. Previous research has demonstrated that immunity to D. immitis can be induced in dogs by repeated chemical abbreviation of infections while the parasite is a fourth-stage larva. Sera obtained from dogs immunized in this manner has been effective in passively transferring larval killing and stunting. These immune sera, by comparison to nonimmune sera from infected cohorts, recognize a number of unique D. immitis antigens, some of which are larval specific. In this study immune dog sera were used to screen a D. immitis larval cDNA expression library. Three overlapping cDNA clones, Di22, Di18 and Di16, were obtained that encode a portion of a large molecule, greater than 150 kDa, that is composed of multiples of a 399-bp repeat. This protein when immunoblotted with antibody against a recombinant expressed Di22 fusion protein is found in larval as well as adult extracts and excretory-secretory products, and is seen as a series of ascending subunits, each approximately 15 kDa larger than the previous one. This antigen is highly immunogenic, as evidenced by the strong reactivity of the recombinant expressed Di22 fusion protein with sera from immune dogs, microfilaremic dogs and infected amicrofilaremic dogs. While the function of this antigen is unknown it has significant sequence similarity with an allergen found in Ascaris.


Inter-species variation of schistosome 28-kDa glutathione S-transferases. The 28-kDa glutathione S-transferase from Schistosoma mansoni (Sm28GST) is a candidate vaccine antigen. To evaluate the antigenic and phylogenetic variations between the 28-kDa GSTs from 4 species of schistosome, we have cloned and sequenced the 28-kDa GSTs from Schistosoma haematobium (Sh28GST) and Schistosoma bovis (Sb28GST). Sb28GST and Sh28GST are more similar to each other (97%) than to Sm28GST (90%) and particularly to the 28-kDa GST from Schistosoma japonicum (Sj28GST, 77%). Antisera directed against the major Sm28GST epitopes revealed differences in the recognition of the 28-kDa GSTs from the other schistosome species suggesting that these regions have been subjected to evolutionary pressure. The consequences of such species-specific epitopes on the development of a multi-species anti-schistosome vaccine are discussed.


Classification of subgroups of Giardia lamblia based upon ribosomal RNA gene sequence using the polymerase chain reaction. A sensitive and specific polymerase chain reaction-based assay has been developed to detect and analyze polymorphism in the Giardia lamblia 18S ribosomal RNA gene. Efficient amplification required the inclusion of cosolvents (glycerol and dimethyl sulfoxide) in the reaction. Following the optimization of conditions for amplification and subsequent hybridization of amplified product with radiolabeled oligonucleotide probe, a detection limit of less than one organism's worth of DNA was achieved. Thirty-five different G. lamblia strains obtained from various human and animal host types and geographic locations were analyzed by this method. The strains could be divided into 3 groups on the basis of defined nucleotide substitutions within the 183-bp amplified DNA fragment of the 18S ribosomal RNA gene. The groupings based upon the 18S ribosomal RNA gene sequence correlated with groupings previously assigned based upon patterns of surface antigens and restriction enzyme analysis. Analysis of the G. lamblia 18S ribosomal RNA gene sequences present in fecal specimens obtained from giardiasis patients revealed the presence of the different sequence types in these specimens. Some specimens contained more than one sequence type. The identification of subgroups of G. lamblia may facilitate studies of virulence, infectivity, and the epidemiology of giardia infection.


Ribosomal DNA sequence comparison of Babesia and Theileria. Previous studies on the taxonomy of Babesia spp. (phylum Apicomplexa) using morphological and life cycle characteristics have resulted in their classification into 3 subgenera, with the genus Theileria being most closely related to them. Using a strategy based on the direct sequence analysis of products derived by asymmetric PCR to determine the nucleotide sequences, we have tested the validity of this classification by sequencing the small subunit ribosomal RNA genes amplified from 2 Babesia species, namely Babesia bovis and Babesia rodhaini, and comparing these with previously published sequences of Theileria annulata and Babesia bigemina using Plasmodium falciparum as an outgroup. The results of this phylogenetic analysis support the recognition of at least 2 genera in Babesia--one to include B. bigemina and B. bovis, the other to include B. rodhaini.


Clinical determinants of the racial disparity in very low birth weight. Although the risk of very low birth weight (less than 1500 g) is more than twice as high among blacks as among whites in the United States, the clinical conditions associated with this disparity remain poorly explored. We reviewed the medical records of over 98 percent of all infants weighing 500 to 1499 g who were born in Boston during the period 1980 through 1985 (687 infants), in St. Louis in 1985 and 1986 (397 infants), and in two health districts in Mississippi in 1984 and 1985 (215 infants). The medical records of the infants' mothers were also reviewed. These data were linked to birth-certificate files. During the study periods, there were 49,196 live births in Boston, 16,232 in St. Louis, and 16,332 in the Mississippi districts. The relative risk of very low birth weight among black infants as compared with white infants ranged from 2.3 to 3.2 in the three areas. The higher proportion of black infants with very low birth weights was related to an elevated risk in their mothers of major conditions associated with very low birth weight, primarily chorioamnionitis or premature rupture of the amniotic membrane (associated with 38.0 percent of the excess proportion of black infants with very low birth weights [95 percent confidence interval, 31.3 to 45.4 percent]); idiopathic preterm labor (20.9 percent of the excess [95 percent confidence interval, 16.0 to 26.4 percent]); hypertensive disorders (12.3 percent [95 percent confidence interval, 8.6 to 16.6]); and hemorrhage (9.8 percent [95 percent confidence interval, 5.5 to 13.5]). The higher proportion of black infants with very low birth weights is associated with a greater frequency of all major maternal conditions precipitating delivery among black women. Reductions in the disparity in birth weight between blacks and whites are not likely to result from any single clinical intervention but, rather, from comprehensive preventive strategies.


Mechanism of dialysis-induced hypotension. Dialysis-induced hypotension, the sharp decrease in blood pressure occurring during hemodialysis, remains one of the most difficult problems associated with hemodialysis even today. However, there is yet no established theory to explain the mechanism triggering dialysis-induced hypotension. This review attempts to offer a consistent and cohesive source of information on the hemodynamics during dialysis-induced hypotension, and then analyzes etiologic factors in such hypotension reported by various investigators. Finally, three hypotheses concerning the mechanism of dialysis-induced hypotension including our own are introduced.


Regulatory role of heat shock protein-specific T cells in host defense. During infection with L.monocytogenes, a facultative intracellular bacteria, TcR gamma/delta T cells specific for 65 kd hsp precede TcR alpha/beta T cells specific for the listerial antigens in appearance. The gamma/delta T cells provide a first line of defense against the infection by recognizing exogenous and endogenous 65 kd hsp on infected cells and producing cytokines such as gamma IFN. The hsp-specific T cells respond quickly to antigenically diverse pathogens before antigen-specific T cells expand clonally, and they play a role in covering the gap between the phagocytic system and highly evolved immune response. 65 kd hsp-specific T cells play important roles not only in host defense mechanism against infection with various pathogens but also in induction of auto-immune disease. Both 65 kd hsp-specific gamma delta T cells and 65 kd hsp-specific alpha beta T cells abrogate the unresponsiveness of the self-reactive alpha beta T cells and/or B cells by producing IL-2 and contribute to induction of autoimmune disease.


Progression of avascular necrosis of femoral head and choice of treatment. Observations of the disease course mainly by X-ray were made in 52 patients (85 joints) with avascular necrosis of the femoral head to determine the prognosis and to decide on treatment. The progression of the necrotic area is related to the activity of the original disease, to the size of the necrotic area in the early stages of the disease, and to whether or not the patient received steroid treatment. On the basis of the size and location of the necrotic area, the disease process is divided into four stages, I to IV. The affected heads are also classified into six types according to their site and extent, the degree of flatness of their weightbearing surface, and the presence of cystic lesion. Preventive treatment and conservative observation or transtrochanteric anterior rotational osteotomy and vascularized pedicle bone graft are applicable to cases in Stages I and II. Total hip joint arthroplasties and salvage procedures are performed in Stages III and IV. The usefulness of 99mTc bone scintigraphy was unexpectedly disappointing for diagnosis of the stages of the disease. However, MRI was sensitive for the diagnosis in the early stages of the disease.


Isolation and some biochemical properties of porcine pancreas mitochondria. Morphologically and functionally intact mitochondria were isolated from the porcine pancreas using a conventional, differential centrifugation method. The homogenate of the porcine pancreas made in a medium containing 0.25 M sucrose, 10 mM Tris-Cl, pH 7.4, 0.5% bovine serum albumin and 1 mM EDTA, in the presence or in the absence of dibucaine and trypsin inhibitor, was centrifuged for 10 min at 700xg. The supernatant was centrifuged for 10 min at 7000xg, and the pellet was washed three times. Trypsin activity of mitochondria isolated in the absence of dibucaine and trypsin inhibitor was as low as that of mitochondria isolated in the presence of dibucaine and trypsin inhibitor, and a major part of the activity remained inactivated. Phospholipase A2 activity of the former mitochondria was as low as that of the latter, and remained unchanged up to 8-10 hr at 4 degrees C. The presence of bovine serum albumin and EDTA in the respiration medium was absolutely required to obtain good respiratory controls of those mitochondria. These data suggest that well-coupled mitochondria can be obtained from the pancreas by a conventional isolation procedure without activating the major part of trypsin.


Esophageal stenting with a self-expandable metallic device: a preliminary study. This study was designed to investigate the potential of the Gianturco-Rosch Z stent in the alimentary canal, using the rabbit esophagus as the animal model. Single stents were implanted in four animals, which were followed up for predetermined periods, lasting from 48 hours to 6 weeks. All the stents remained in place. A florid tissue reaction was noticed, initially manifesting primarily as submucosal cellular infiltration, and mucosal erosion. Over the ensuing six weeks, the acute changes gave way to mucosal regeneration, and the appearance of granulation tissue in the submucosa. The stented segments remained patent, and feeding difficulties were limited to the immediate post-procedure period. These preliminary results suggest that peristaltic activity is no contraindication to the use of Z stents, though measures to limit the tissue response need to be identified.


The effect of hypophysectomy on proluminal movement of 3H-androgens across the epididymal epithelium in the rat. The effect of hypophysectomy on transepithelial movement of 3H-androgen in the rat epididymis was examined by using in vivo microperifusion of 3H-testosterone followed by in vivo micropuncture to obtain peritubular and intraluminal fluids. Experiments were performed on animals without hypophysectomy or on animals 5-6 days after hypophysectomy and 9-10 days after hypophysectomy. Tubules were perifused with Minimum Essential Medium containing 3H-testosterone. 14C-polyethyleneglycol was included in the perifusion fluid as a marker for contamination of the intraluminal fluid by peritubular fluid. Radioactivity of isotopes in the interstitial and intraluminal fluid was determined at 1 and 2 hours after perifusion and the percentage of peritubular isotopes appearing in the intraluminal fluid was determined. A sperm concentration microassay was performed on micropuncture samples from the epididymal tubules to assess testicular contribution to the lumen content. Proluminal movement of 3H-androgen and intratubular sperm concentrations in the caput epididymal tubules of rats 9-10 days after hypophysectomy were significantly decreased. Proluminal movement of 3H-androgen and intratubular sperm concentrations in the cauda epididymal tubules of rats 9-10 days after hypophysectomy were significantly increased. These results suggest that proluminal androgen movement is controlled by the presence of some testicular product in the epididymal lumen.


Remarkable hepatic vein-to-vein anastomoses in giant cavernous hemangioma of the liver: a case report. Intrahepatic venous collaterals develop in Budd-Chiari syndrome, hepatomas, and other tumors if the hepatic veins are obstructed. In portal hypertension hepatic vein-to-vein anastomoses develop without obstruction of the hepatic veins. In a 53-year-old woman with giant cavernous hemangioma of the liver, hepatic venography demonstrated remarkable hepatic vein-to-vein anastomoses in the periphery of the hepatic veins without venous obstruction, accompanied with low wedged hepatic vein pressure. The hemodynamic change of the liver may cause this abnormality because of the large blood space of the hemangioma. Pathological examination of the resected liver apart from the tumor confirmed numerous deformations and dilatations of the central veins not found in the normal liver, in the area of hepatic vein-to-vein anastomoses shown by venography. Clinically, atypical hepatic resection is possible by maintaining a drainage vein to preserve as much of the normal liver as possible. Hepatic venography, as well as hepatic angiography, gives important information about the liver.


Movement study following anterior cervical decompression without fusion. Movement studies of the neck have shown that certain patients with cervical spondylotic myelopathy (CSM) demonstrate instability in the vertebral joint immediately above the posterior osteophytic bar. While Cloward's anterior cervical decompression with fusion eliminates the cord or root compressive element, it adds to the hypermobility of the adjoining vertebral segment. In an attempt to reduce the hypermobility or subluxation, anterior cervical decompression without fusion was carried out on a selected group of twenty-three patients with spondylotic cervical myelopathy in whom the cord compression was mainly at a single level. Follow-up cineradiographic studies of these cases demonstrated the continued preservation of the range of movement of the adjoining vertebral segments and in 30%, a return of normal functional mobility to the affected cervical intervertebral joint. The findings and results of anterior cervical decompression surgery to a single level are reported.


Inhibitory effects of okadaic acid on thyrotropin and prolactin secretion from rat anterior pituitaries. The present study was undertaken to elucidate the effects of okadaic acid, a potent inhibitor of protein phosphatases, on thyrotropin (TSH) and prolactin (PRL) secretion, and on the hydrolysis of inositol phospholipids in rat anterior pituitaries. Preincubation of anterior pituitaries with okadaic acid caused a dose dependent decrease in TRH- and K(+)-induced TSH secretion, whereas basal secretion of TSH was not affected by pretreatment with okadaic acid. In contrast, okadaic acid resulted in a marked inhibition in both basal, and TRH- and K(+)-stimulated PRL release from anterior pituitaries. In addition, pretreatment with okadaic acid caused a slight, but significant decrease in the formation of [3H]inositol phosphate ([3H]IP) in rat anterior pituitaries. The present study suggests that okadaic acid blocks the release of TSH and PRL by inhibiting Ca2+ influx and that inhibitory effects of okadaic acid on PRL release are, at least in part, due to the inhibition of inositol phospholipid hydrolysis.


The effect of C-terminus and N-terminus iodination on avian pancreatic polypeptide (APP) binding to its chicken brain receptor. In previous studies, membranes from chicken gastrointestinal tissues failed to bind appreciable levels of 125I-APP labeled at the C-terminus. In order to address the suggestion that this was due to steric hindrance of the critical C-terminus, N-terminally labeled 125I-APP was utilized in in vitro membrane binding assays. Membranes from chicken cerebellum and spleen specifically bound N-terminally iodinated APP, while those from gastrointestinal tissues including pancreas, mucosal and muscle layers of duodenum and proventriculus did not. Cerebral cortex membranes also failed to specifically bind Bolton-Hunter labeled 125I-APP. Liver membranes, which previously were shown to bind C-terminally iodinated APP with low affinity, also did not specifically bind N-terminally labeled preparations. It is concluded that the inability of membranes from gastrointestinal tissues and brain regions other than cerebellum to bind 125I-APP is not an artifact of location of iodine placement on the molecule and that both the N- and C-termini may be important for receptor binding. It is also concluded that liver APP binding sites may be structurally distinct from those in the cerebellum, and that gastrointestinal tissues may not be direct targets for APP action.


Sites of synthesis of chromogranins A and B in the human brain. The sites of synthesis of the chromogranins A and B, and their potential processed peptides, were examined by quantitating the levels of chromogranin A and B mRNA in various regions of the human brain by Northern blot analysis. Chromogranin A and B mRNA expression in the brain is region-specific and confined to grey matter. In situ hybridization histochemistry detected chromogranin A and B mRNA in pyramidal neurons of human cerebral cortex. Cell-specific expression in subpopulations of cerebrocortical neurons suggest that chromogranin A and B gene products may play a role in central neuronal function.


Glycosylation variants of endopeptidase-24.11 ('enkephalinase'). Anion exchange chromatography resolves two charge variants of rat kidney endopeptidase-24.11 (designated NEP 1 and NEP 2); each was purified to homogeneity using immunoaffinity chromatography. In addition to charge differences the subunit molecular weights of NEP 1 and NEP 2 differ and are 89 and 96 kDa, respectively. Isoelectric focusing resolved 8-10 pl species in the pH range of 5.95-6.20 for NEP 1 and 5.46-6.06 for NEP 2. Removal of sialic acid residues converted the multiple pl species to one form with a pl of 6.32 for NEP 2, and two forms with pls of 6.27 and 6.32 for NEP 1. Endoglycosidase H or F, capable of removing high-mannose and biantennary branched N-linked oligosaccharides, produced a 2-3 kDa decrease in the molecular weight of both NEP 1 and NEP 2. Peptide-N-glycosidase F, capable of removing all classes of N-linked oligosaccharides, produced 8 and 11 kDa decreases in NEP 1 and NEP 2, respectively. Removal of all N-linked and O-linked oligosaccharides with trifluoromethanesulfonic acid resulted in 10 and 15 kDa decreases in NEP 1 and NEP 2, respectively. Tryptic epitope maps demonstrated that NEP 2 was cleaved at a slower rate than NEP 1. These analyses demonstrate that rat kidney NEP exhibits sialic acid microheterogeneity resulting in two distinct change variants. The data also indicate that NEP 2 contains more N- and O-linked carbohydrate mass than NEP 1 and may contain a larger polypeptide backbone giving rise to molecular weight differences between these enzyme forms.


Decision making. Stability of clinical decisions. Clinical decisions of 101 medical-surgical nurses were examined for stability. Results indicate that slightly more than 50% of the subjects made stable clinical decisions or decisions not likely to be reversed with minor changes in the clinical data. The findings also reveal that stability was related to hospital setting and country in which the nurses received their education. The authors provide possible explanations for these observations, and recommendations for nursing education and practice.


An approach to publishing an edited book. This article outlines the steps taken by the authors to publish a co-edited nursing research book to assist nurses interested in editing a book or writing a book chapter. The authors' experiences are used to help illustrate the preparation and editing of manuscripts. Collaboration among co-editors, chapter authors (contributors), and the staff of the publishing company is vital when publishing an edited book.


Client satisfaction with student care in a nurse-managed center. Nursing faculty across the country are developing nurse-managed centers to provide students with community health experiences. Although students deliver much of the care provided within nursing centers, the literature offers little data on the quality of student-rendered care. This study evaluated client satisfaction with care received from student nurses. Results have direct implications for faculty supervising students in community health nursing agencies.


Strategies to enhance problem solving.

Strategies to enhance problem solving. The ability to make high-level decisions based on a strong knowledge base and effective problem-solving strategies is an expected behavior of the professional nurse. The author discusses current knowledge of problem-solving components and teaching strategies as well as promising new computer strategies that are applicable to nursing education and practice.


The optimal environment for socialization of the nurse-scientist. Tangible elements or factors that contribute to the successful socialization of student scholars seeking the PhD degree in nursing are generally well known. Included among these are the university itself-its faculty, its resources, such as laboratories and libraries, and its research productivity. Less well known are some intangibles in the learning environment that make the difference between an acceptable learning environment and an optimal one, such as, the frequency and quality of informal interaction between faculty and students. The author identifies several characteristics of the pre-doctoral learning environment for nurse PhD students that faculty and administrators should seek to provide if they wish to support truly successful socialization of the scholar/scientist.


A classroom activity to introduce cultural diversity. The authors describe an activity designed to introduce cultural diversity to an undergraduate developmental psychology course in a nursing baccalaureate program. The students' responses to the activity served as the basis for a discussion of stereotypes and their effects on culturally diverse populations. The student responses are described and the importance of introducing cultural diversity into mainstream education is discussed.


Linking community needs with student research experiences. The authors describe the activities of the Action Research program, designed to link academic projects and requirements for student research activities with the information needs of community service agencies. While interdisciplinary in focus, this program has been especially helpful in allowing community health nursing students to gain practical experience with real-life research questions and processes. An added benefit is to instill in the student an attitude of service while expanding their orientation to the community and the everyday needs of its agencies.


Bronchitis mimicking opportunistic lung infection in patients with human immunodeficiency virus infection/AIDS. Purulent bronchitis was identified in 19 of 422 patients undergoing fiberoptic bronchoscopy during a 32-month period because of suspicion of an opportunistic lung infection complicating acquired immunodeficiency syndrome or human immunodeficiency virus infection. Five patients had Pneumocystis carinii pneumonia, but other opportunistic lung infections were excluded in the remaining 14 patients. Characteristics of these 14 patients included fever (greater than 38.3 degrees C), cough, and dyspnea in 14 of 14 patients; purulence of expectorated sputum (11/14); and widened alveolar-arterial oxygen gradient (13/14). Rapid (2 +/- 1.4 days) clinical response (defervescence and resolution of pulmonary symptoms) occurred with antibiotic therapy in 10 of 14 patients. In three patients, there was no improvement, and adult respiratory distress syndrome developed. Bacterial isolates from bronchoalveolar lavage included Streptococcus viridans (n = 12), Haemophilus influenzae (n = 7), Staphylococcus aureus (n = 3). Roentgenographic features of bronchiectasis were present in seven patients. Differential cell counts revealed greater than 50% neutrophils in the bronchial washings of all patients with purulent bronchitis. Neutrophil percentages in bronchoalveolar lavage were as follows: patient with purulent bronchitis without P carinii pneumonia (n = 14), 54.53% +/- 29.18%; patients with purulent bronchitis and concomitant P carinii pneumonia (n = 5), 62% +/- 31.9%. In a control group of 17 patients with P carinii pneumonia who did not have purulent bronchitis, the neutrophil percentage was 6.8% +/- 6.17% (p = less than 0.00001, t-test). Purulent bronchitis appears to be a distinct, treatable entity in patients with HIV infection and may accompany bacterial pneumonia, bronchiectasis, and P carinii pneumonia.


Developing case studies.

Developing case studies. The case method stimulates critical thinking through problem analysis of real or hypothetical cases. Developing clear, concise, fact-filling cases that promote problem solving in the classroom is not easy. The author presents a systematic, seven-step process for case construction.


A retrospective study of patients with cluster headaches. Referred pain in the midface and teeth is a common clinical feature of the cluster headache and cluster headache-like disorders. It is not unusual therefore for patients with cluster headaches to go to the dentist. In this report, 33 cases of cluster headache, which met the International Headache Society classification criteria, and which were seen by us during a 2-year period, are reviewed. Fourteen (42%) of 33 patients who were seen by dental practitioners and who received some form of ineffective dental or pharmacologic treatment are described here. Since almost 50% of the cluster headache patients described here received inappropriate dental treatment, it is hoped that this review and retrospective assessment will make the dental practitioner aware of this disorder and provide a broader perspective in the treatment of pain in the orofacial region. Clinical presentation, pathogenesis, and treatment of cluster headaches are discussed.


Lateral canthotomy transconjunctival approach to the orbit. Multiple surgical approaches to the orbits with the use of the eyelids have been used. The orbital rim incision fell into disfavor because of esthetic considerations. A subciliary approach supplemented by the lateral brow incision is currently the most popular method of approach to the orbital rim. It provides adequate access to the orbit, but it is not without inherent complications, such as unfavorable scarring, ectropion, and entropion. This article describes an alternate approach to the orbit by means of a transconjunctival incision with lateral canthotomy.


Rehabilitation of the temporomandibular joint after arthroscopic surgery. Arthroscopy of the temporomandibular joint (TMJ) is a new, relatively noninvasive surgical procedure for treating patients with TMJ dysfunctions beyond management by nonsurgical means. Ninety-two patients who underwent diagnostic and operative TMJ arthroscopy completed a staged physical therapy regimen, which resulted in functional mobility and mandibular use with little or no pain at 24-month follow-up. This report introduces TMJ arthroscopic diagnostic and surgical procedures and their respective rehabilitative protocols currently used to provide beneficial outcomes in postoperative treatment.


Pulpal anesthesia dependent on epinephrine dose in 2% lidocaine. A randomized controlled double-blind crossover study. We studied the discrepancy in the results published on the dependence of the duration of pulpal nerve anesthesia on the concentration of epinephrine in 2% lidocaine. The increase in pain threshold of the pulpal nerve was measured before and after injection of lidocaine alone and lidocaine with epinephrine concentrations of 1:200,000, 1:100,000, or 1:50,000 into the mucobuccal aspect adjacent to the apex of the maxillary right incisor. The study was done in a random manner with a double-blind crossover design. The pulpal nerve was stimulated with negative rectangular electrical pulses of up to -167 V with 100 Hz and a pulse width of 0.6 msec. The results show a relationship between the 1:200,000 and 1:100,000 epinephrine concentrations and the success and duration of anesthesia. The onset of anesthesia was independent of the catecholamine content of the solution.


Replacement of freeze-dried allogeneic cartilage chin graft with host bone. A case report. Facial contour and augmentation procedures are frequently performed by oral and maxillofacial surgeons either as a primary surgery or in conjunction with corrective jaw surgery. The success of these procedures depends on the stability of the material used. This case demonstrates the stability and eventual osseous replacement of allogeneic freeze-dried cartilage as an augmentation material.


Two natal maxillary molars. Report of a case. A 20-day-old black male infant with two rare posterior natal teeth was referred for examination and care. Oral radiographs suggested that the teeth were the right and left maxillary primary molars. The hypermobile teeth and associated suspicious soft tissue masses were removed. Histologic examination revealed irregular tooth structures and infiltrate consistent with inflamed dental follicles.


Postscaling bacteremia in HIV-associated gingivitis and periodontitis. Aseptic venipuncture was used to obtain samples of blood from 22 patients seropositive for human immunodeficiency virus (HIV) with gingivitis (HIV-G) and 19 HIV-seropositive patients with periodontitis (HIV-P), 15 and 30 minutes after the initiation of routine dental scaling and root planing. The presence of colony forming units in 1.2 ml aliquots of blood collected with the Isostate system (DuPont Isostat System, Doraville, Ga.) was assayed on trypticase soy blood agar. Six of the samples from HIV-G subjects were positive for colony forming units 15 minutes after scaling but not at 30 minutes. Similar evidence of bacteremia was found in seven of the HIV-P patients 15 minutes after scaling was initiated in this group, with no microbial growth detectable in samples obtained at 30 minutes. In two HIV-G and three HIV-P patients with demonstrable bacteremias a postoperative fever developed. For both HIV-G and HIV-P groups no significant difference was found between the absolute CD4 T-cell counts of nonbacteremic versus bacteremic patients (p greater than 0.05). These observations suggest that special provisions for antibiotic prophylaxis in this patient group may be unnecessary.


Retrospective findings of the clinical benefits of podophyllum resin 25% sol on hairy leukoplakia. Clinical results in nine patients. Hairy leukoplakia was first described as an oral marker of human immunodeficiency virus infection in 1984. The clinical significance of this lesion in an otherwise healthy, high-risk symptom-free person is that it can be an early manifestation of human immunodeficiency virus infection. Because of its benign nature and the lack of clinical evidence that treatment of the lesion improves the prognosis of human immunodeficiency virus-infected patients, systemic therapy with antiviral drugs does not seem warranted at this time. Topical retinoids (Retin-A sol) and systemic antivirals such as acyclovir have been previously tried; however, lesions tend to recur a few days after treatment is discontinued. Nine patients with oral hairy leukoplakia seen at the Oral Medicine Clinic, University of California San Francisco were offered treatment with podophyllum resin 25% sol. All patients had a complete remission of their condition within 1 week (5 patients) or after the second application a week later (4 patients). Side effects were transient and reversible. These remissions of oral hairy leukoplakia lasted from 2 to 28 weeks, which suggests that podophyllum may be a relatively safe and cost-effective treatment of this otherwise symptom-free lesion.


Candida species and Candida albicans morphotypes in erythematous candidiasis. A group of full-denture-wearing patients with erythematous candidiasis was matched by age and sex with a group of healthy, full-denture-wearing persons who served as controls. In the group with erythematous candidiasis, clinical symptoms and signs of the disease were recorded. Denture hygiene and tobacco use were noted in both groups. Epithelial smears and imprint cultures were obtained from both groups from specified sites. Cultures were grown and subjected to species identification and C. albicans strain differentiation by a morphotyping technique. Denture-wearing subjects who smoked tobacco had a significantly greater incidence of erythematous candidiasis than the controls. Five species of Candida were isolated from both groups, with C. albicans as the dominant species. Twenty different morphotypes of C. albicans as well as strains involved in erythematous candidiasis were also isolated from the oral cavities of healthy, full-denture-wearing control subjects.


An unusual case of hemifacial atrophy.

An unusual case of hemifacial atrophy. A case of hemifacial atrophy in a 10-year-old boy is described. The presentation in this patient is unusual because the lesion is extremely localized, and the abnormalities of teeth in the affected region are more severe than previously recorded. Alternative diagnoses are considered, and the results of a computed tomographic scan with three-dimensional reformatting are presented.


Chronic ulcerative stomatitis associated with stratified epithelial specific antinuclear antibodies. A case report of a newly described disease entity. A case of erosive oral lesions associated with an unusual direct and indirect immunofluorescent pattern is presented. Rather than a submucosal band or intramucosal intercellular deposition, the pattern is that of an antinuclear antibody that reacts only with stratified epithelium. The clinical similarity of this case to erosive lichen planus is discussed. The usefulness of direct and indirect immunofluorescence techniques in the diagnosis of erosive oral lesions is stressed.


Production of microliths and sialadenitis in rats by a short combined course of isoprenaline and calcium gluconate. The relationship between microliths and sialadenitis in man is unclear, so an attempt was made to investigate it experimentally in rats with the use of isoprenaline and calcium gluconate either alone or combined. The acini of the submandibular and parotid glands of rats that were given isoprenaline were enlarged, and degenerate acinar cells were seen, with extravasated secretions in the submandibular gland. Similar changes were seen in the submandibular and parotid glands of rats that were given isoprenaline combined with calcium gluconate; in addition, ductal microliths with regions of atrophic sialadenitis were observed. The results suggest that there is temporary obstruction to the salivary flow after isoprenaline is injected, and in the rats that were also given calcium gluconate some of the stagnant saliva calcified to form microliths, which produced a lasting obstruction and obstructive sialadenitis. This supports the possibility that microliths, which are present in normal salivary glands of man, are a primary etiologic factor in sialadenitis.


Low-grade papillary adenocarcinoma of minor salivary glands. Case report and literature review. Low-grade papillary adenocarcinoma of minor salivary glands is rare and tends to occur in the palate. This tumor has distinct but rather deceptive histomorphologic features, which may cause erroneous diagnosis. An extensive English-language literature review revealed reports of 22 well-documented low-grade papillary adenocarcinomas. Six of these tumors (27%) recurred locally between 12 months and 19 years after initial treatment. Low-grade papillary adenocarcinoma appears to have more aggressive biologic behavior compared with other low-grade adenocarcinomas in this region. Four of the reported cases (17%) had cervical lymph node metastases at the time of presentation. We report an additional case and discuss the literature.


Intraoral infantile hemangiopericytoma: literature review and addition of a case. A rapidly growing neoplasm in the buccal mucosa of a 4-month-old baby was excised. By light and electron microscopy the neoplasm had features that were similar to those described in infantile hemangiopericytoma, a rare neoplasm of vascular origin. By light microscopy the neoplasm was multilobular with highly proliferating round to spindle-shaped cells interspersed with numerous vascular spaces. Ultrastructurally, round to elongated cells with short processes, pinocytotic vesicles, reduplicated basal lamina, and basal lamina-like material were identified. Immunohistochemically the cells were weakly positive with antibodies to vimentin, focally positive with HHF-35, a smooth-muscle cell antibody, negative with antibodies to S-100 protein, T-200, neuron-specific enolase, neurofilaments, desmin, and cytokeratins 35BH11 and 34BE12. Blood vessels were positive with Ulexeuropaeuslectin, but tumor cells were negative. Reticulin stain decorated a delicate network of fibrils surrounding tumor cells and vascular spaces. Clinically the neoplasm did not recur and the baby has been disease free for more than 26 months. The difficulty of the histologic diagnosis of this neoplasm is discussed and the literature is reviewed, with special emphasis on lesions occurring in the oral cavity.


Unusual oral presentation of non-Hodgkin's lymphoma in association with HIV infection. In 4.4% of human immunodeficiency virus-associated non-Hodgkin's lymphoma the presenting lesion is seen in the mouth. Often the lesion may clinically resemble a less sinister process, and a definitive diagnosis of lymphoma may be delayed. We describe three unusual cases of non-Hodgkin's lymphoma, appearing intraorally in association with other oral lesions, in HIV-positive homosexual men. The three patients reported here were all diagnosed as having diffuse, large-cell malignant non-Hodgkin's lymphoma. We performed Epstein-Barr virus DNA in-situ hybridization on our cases and Epstein-Barr virus DNA sequences were not seen. We review the pertinent literature and stress the importance of including non-Hodgkin's lymphoma in the differential diagnosis of oral lesions in patients at risk of HIV infection.


Efficacy of removing glass ionomer cement, zinc oxide eugenol, and epoxy resin sealers from retreated root canals. Removal of gutta-percha and various sealers was assessed during retreatment of the root canal system. Sixty root canals were prepared and obturated with gutta-percha and Ketac-endo, Roth's 801 cement, or AH26. After 14 days, the canals were retreated by hand or ultrasonic technique and the retreatment time was recorded. The roots were split and the amount of debris that remained on the canal walls in three separate levels was recorded by use of a dissecting microscope. The mean scores were compared by one-way and two-way ANOVA. The total score was significantly the highest for Ketac-endo (p less than 0.04), followed by AH26 and Roth's 801 cement. The largest amount of debris was consistently found in the apical third, and generally it was comparable for both retreatment techniques. The ultrasonic technique was significantly faster than the hand technique for all sealers tested (p less than 0.0004, p less than 0.0003, p less than 0.02, respectively). Hand retreatment of Ketac-endo was the slowest, whereas ultrasonic retreatment of Roth's 801 cement was the fastest. The results indicated that Ketac-endo endodontic sealer can be effectively removed from the root canal by ultrasonic instrumentation.


In vivo comparison of the biocompatibility of two root canal sealers implanted into the mandibular bone of rabbits. The purpose of this study was to evaluate the in vivo biocompatibility of two zinc oxide-eugenol-based sealers, Sealite and Pulp Canal Sealer, after implantation into the mandibular bone of rabbits. Thirty female New-Zealand rabbits were randomly divided into three groups on the basis of the material to be implanted in each side of the mandible: six rabbits received a positive control implant (silicone tubes filled with asbestos) in both sides of the mandible; 12 rabbits received a Sealite implant in the left side and a negative control implant (silicone tubes filled with silicone adhesive) in the right side of the mandible; and 12 rabbits received a silicone tube filled with Pulp Canal Sealer in the left side and a negative control implant in the right side of the mandible. The sealers were implanted in a freshly mixed, unset state. The rabbits were killed 4 or 12 weeks after implantation and the implants and surrounding bone were sectioned and treated in accord with standard histologic procedures. The tissue reactions were scored and rated as none, very slight, slight, moderate, severe, and very severe. The statistical analysis of the data showed that the two sealers had similar, good biocompatibility, and that the reactions observed at the 12-week period were better than those observed at the 4-week period. Both sealers may be used indifferently in routine endodontic practice.


Preliminary evaluation of a digital system for rotational panoramic radiography. A prototype system for direct digital panoramic radiography has been evaluated with respect to density, contrast, magnification, distortion, resolution, and overall image quality. Density and contrast depend on detector calibration and may be modified by the display system or by digital processing of the captured image. Variation of magnification in the horizontal and vertical dimensions gives rise to distortion phenomena that are identical to those encountered in film-based systems. Resolution in the vertical dimension is determined by the pitch of the detector elements. In the horizontal dimension, resolution is limited by the effective width of the detector elements. To evaluate the clinical acceptability of the images, radiologists and general practice residents were asked to assess the perceptibility of important radiographic landmarks in film-based and digital images of both a radiographic phantom and a patient. The digital system performed on a par with film in the representation of normal morphologic structures of the clinical human subject whereas more differences were apparent in the phantom images. The general practice residents consistently rated the digital images higher than their radiologist counterparts did. No consistent trends were found to indicate any inherent deficiencies of the digital system in the depiction of any one area. The results indicate the promise of direct digital acquisition as a method of panoramic imaging.


A radiologic study of pulmonary metastases originating from oral and maxillofacial tumors. A retrospective clinical and radiologic study was carried out on 103 consecutive cases of oral and maxillofacial malignant conditions in which pulmonary metastasis occurred. The most frequent primary site was the palate. The neoplasm most commonly involved was the adenoid cystic carcinoma. Pulmonary metastases were classified into five types: solitary, multiple nodular, multiple "massy," diffuse, and miliary.


Dosimetry of absorbed radiation in radiographic cephalometry. Absorbed radiation was measured in various craniofacial tissues on an adult phantom (Alderson Rando) when conventional cephalometric radiographic techniques were used. The views examined were lateral, 45 degrees oblique, posteroanterior, lateral temporomandibular joint tomograph, and basilar (submental-vertex). Absorbed radiation was expressed in micrograys for the individual views and for combinations of views as customarily used in orthodontics and oral surgery. These data are compared with findings of contemporary investigators and the magnitude of the doses is compared with those in the literature for periapical and panoramic surveys.


Calmodulin binding sites in the endolymphatic sac and stria vascularis of the human fetus and the guinea pig. Calmodulin (CaM) binding sites, which are available and unoccupied by CaM at the time of fixation, were analyzed in the guinea pig endolymphatic sac and stria vascularis using CaM conjugated tetramethyl rhodamine isothiocyanate. The endolymphatic sac epithelium and stria vascularis both showed strong fluorescence. Weak CaM binding sites were seen in the endolymphatic sac in the 12-week-old human fetus. In contrast, the fluorescent reaction in the stria vascularis and endolymphatic sac in 14- and 15-week-old human fetuses was strong. These results suggest that CaM may play an important role for the maintenance of ionic stability in the endolymph.


The length of isolated outer hair cells is temperature dependent. In the mammalian cochlea, motile properties of outer hair cells may contribute to sharp tuning and amplification. Length changes of isolated outer hair cells in response to various physical and chemical stimuli have therefore been investigated by many laboratories. The present study shows that alteration of temperature changes the length of outer hair cells of the guinea pig cochlea as much as 0.22 micron/degrees C. Thus, length changes in response to alterations of temperature are similar to length changes in response to other physical and chemical stimuli.


Histochemical localization of glycoconjugates in the developing endolymphatic sac and vestibular end organs of the mouse. The distribution of glycoconjugates in the endolymphatic sac (ES) and vestibular end organs from the 12th gestational day (GD) in the developing mouse to the 6th day after birth was analyzed using six biotinylated lectins: wheat germ agglutinin (WGA), Abrus precatorius agglutinin (APA), Ulex europaeus agglutinin I (UEA-I), Ricinus communis agglutinin 120 (RCA120), Helix pomatia agglutinin (HPA), concanavalin A (conA). In the 13th and 15th GD sections, the luminal contents in the fetal ES were strongly labelled with lectins, while only a small amount of substance in the ES was labelled with lectins after the 17th GD. In the 13th GD sections, before the cupula and otoconia were formed, the fetal ES started to produce glycoconjugates labelled with WGA, APA, RCA120 and ConA. In the 17th GD sections, the immature cupula and otoconia were strongly labelled with WGA, APA and RCA120. Sugar residues stained by lectins detected in the substance of the fetal ES were the same as those found in the immature cupula and otoconia. HPA only stained the ES epithelium around the 13th and 15th GD. The fetal ES may interact with the formation of the cupula and otoconia, especially in the early stage during evolution and that HPA-reactive glycoconjugates may be related to the intracellular elements of the ES epithelium only during a well-defined phase of development.


Effect of ambroxol on rabbit eustachian tube surfactant. The effect of ambroxol administration on phospholipid and phosphatidyl-choline contents of rabbit eustachian tube and lung washings and on [14C]-choline incorporation by rabbit eustachian tube and lung tissue has been studied. Despite minor differences, the drug exerts the same activating effect in both locations. The results add a further piece of evidence to the several similarities existing between the lung surfactant and the surface-active substances present on the eustachian tube.


Evaluation of the galvanic vestibulo-ocular response recorded with a modified electronystagmographic technique. Previously, a simple method for recording galvanic nystagmus (GN) using conventional electronystagmography (ENG) was demonstrated. The present study reports on investigations made to examine the applicability of that technique. During a standard stimulus over 20 s, amplitudes and rate of saccades show no tendency to diminish. In a series of 10 repeated standard stimuli over 16 min, a parabolic relationship is observed between time on one side and on the other, the mean amplitude, the mean rate of saccades and the sum of amplitudes per stimulus duration. The threshold of GN was 1.29 mA and that of induced tilting sensation 3.64 mA. In a series of 8 repeated threshold stimuli, thresholds of GN and tilting sensation linearly increase (p less than 0.001). During the slow increase of the current, the amplitudes and frequency of saccades and the slow-phase velocity linearly increase (p less than 0.01). The direction of per- and poststimulatory galvanic nystagmus and tilting sensation were investigated. Several autonomic reactions and psychophysical sensations during stimulation were noted. In conclusion, it is thought that the modified ENG technique is a valid method for further clinical use and basic research and its applicability has proven to be good.


Diagnosis of cerebellopontine angle tumors. Between 1980 and 1990, 9,176 patients suffering from otoneurological disorders were investigated in our clinic. Sixty-six (0.72%) internal auditory canal or other cerebellopontine angle tumors (CPAT) were diagnosed. Brainstem auditory evoked potentials (BAEP), interaural time discrimination, and magnetic resonance imaging (MRI) revealed to be the most sensitive and efficient tests for the detection of CPAT. However, the investigation of otoneurological symptoms cannot be limited to BAEP and MRI on the a priori of a hypothetical CPAT. Electrophysiologic tests such as impedancemetry, and electronystagmographic testing are also needed to elucidate the many causes of otoneurological symptoms.


Middle ear inflation with a gas mixture. We studied the middle ear (ME) pressure in 13 atelectatic ears to evaluate the effect of politzerization or ME inflation by a catheter using both room air and a gas mixture. The gas contained 12% O2, 6% CO2 and 82% N2. Tympanometry was performed before and after the treatment. The elevated ME pressure induced by the treatments, whether with room air or the gas mixture, declined rapidly within the first 30 min. However, at 35 and 45 min after the treatment with room air, the mean decrease in pressure was significantly greater than with the gas mixture, which might be due to slow oxygen absorption through the ME mucosa.


Cochlear function after stapedectomy.

Cochlear function after stapedectomy. The short-term and long-term results of stapedectomy for eliminating the conductive element and improving the hearing in patients with otosclerosis are highly satisfactory all over the world. The delayed sensorineural hearing loss which continues after successful stapedectomy may be due to the operation itself or due to the natural history of the disease. The study was conducted on 80 patients with unilateral stapedectomy with a minimal follow-up period of 1 year. We found that bone conduction values at each frequency in operated ears were stable with marked improvement at 2,000 Hz, on the other hand, the bone conduction thresholds in non-operated ears significantly deteriorated (p less than 0.001). The speech discrimination score was significantly improved in the operated group (p less than 0.001). An explanation for the cochlear changes in operated and non-operated ears is presented.


Effect of H2-blockers, cimetidine and famotidine, on histamine nasal provocative test. The H2-receptor is considered to mediate the stabilization of the membrane of mast cells by enhancing cAMP synthesis. In the present study, we investigated the effect of H2-receptor antagonists, i.e. H2-blockers, on nasal hypersensitivity using a histamine nasal provocative test. A 7-day administration of cimetidine tended to lower the histamine threshold. Famotidine administered in the same way caused no significant decrease in the histamine threshold. Based on the above results, we postulate that famotidine should be preferred to cimetidine as an H2-blocker in patients with gastric and/or duodenal ulcers.


Direct observation of living laryngeal carcinoma cells during invasion of healthy cell formation. After cloning of laryngeal carcinoma cells from tumor fragments obtained during surgery, the behavior of pure tumor cells was investigated under the inverted microscope. In tissue culture flasks, separately grown tumor cell layers and fibroblast layers were cocultured to visualize the invasion of malignant cells into healthy tissue. Using a time-lapse camera, the cells were recorded. The tumor cells often penetrated the healthy cell formation in a wedge-shaped cell formation. Near the tumor front, an elevated cell motility was found accompanied by continuous changes in the cell shape. Intercellular gaps were broader in the front line than in the more posterior parts of the tumor cell formation. The profound motility of the carcinoma cell enabled selected cells to leave the tumor cell formation completely and to migrate as single cells through healthy tissue. Eventually, some of the single tumor cells migrating through the fibroblast layer moved back to the tumor cell formation. Thus they left healthy appearing tissue behind which was earlier infiltrated by a malignant cell.


Ventricular fibrillation following local application of cocaine and epinephrine for nasal surgery. We report the case of a 17-year-old female patient, scheduled for septoplasty under general anesthesia, who developed ventricular fibrillation after intranasal application of cocaine (350 mg) and submucosal injection of lidocaine (20 mg) with epinephrine (100 micrograms). Resuscitation by external chest compression was successful, and normal sinus rhythm was reestablished after lidocaine injection (50 mg, i.v.). The cardiac risk of the combined administration of cocaine and epinephrine during general anesthesia are discussed.


Laryngeal paraganglioma and pregnancy.

Laryngeal paraganglioma and pregnancy. Paraganglioma is an uncommon tumor of the larynx. We present a 30-year-old woman with a paraganglioma which took a heretofore not described clinical course. The first clinical sign was persistent hoarseness, when she was 26 weeks pregnant. A histological examination of a piece of the reddish, racemose tumor removed during microlaryngoscopy revealed only some slight nonspecific inflammatory changes. The patient remained free of symptoms following this operative procedure until 3 years later when she presented with a recurrence of hoarseness and a laryngeal tumor and was 25 weeks pregnant. Histology showed a laryngeal paraganglioma in the same supraglottic localization as before. Histological studies failed to confirm the obvious suspicion that the episodic growth of the paraganglioma may have been induced by estrogen or gestagen. To date, 6 years after the removal of the tumor, there has been no recurrence.


Parenting enhancement among Egyptian mothers in a tertiary care setting. This study tested the efficacy and effectiveness of systematically planned parenting enhancement program aimed toward breaking the cycle of high-risk mothers producing high-risk babies in Egypt. The assumption is that self-esteem and self-care are requisites to effective parenting, which can be enhanced or impeded by human and environmental forces. Given that parenting is a learned behavior, it can be repatterned by modifying human-environmental processes.


Comparison of preparation and narcotic-sedative premedication in children undergoing surgery. A psychological preparation program was developed for use prior to emergency surgery in children. The purpose of this study was to test the hypothesis that provision of specific information prior to an emergency operation would reduce the need for premedication to control anxiety and stress. Children were randomly assigned to either a verbally prepared group given narcotic-sedative premedication (control) or to a psychologically prepared group given only atropine as premedication. The child and parent rated their own anxiety on a Visual Analogue Scale (VAS). The children and parents were also assessed by a nurse preoperatively and postoperatively using a similar scale. The children's pulse, blood pressure, and cortisol were also measured. The results showed no significant difference between the psychologically prepared group and the premedicated group, suggesting that psychological preparation compares favorably with narcotic-sedative premedication.


The reactions of Chinese children who have cancer. While many studies have explored the impact of childhood cancer on children and their families, few articles have examined the effects of this disease on selected cultural groups. Reactions of children and families in a select group from the People's Republic of China are described.


Factors influencing visits to school nurses by pregnant adolescents. The influence of five factors on the first visit to school nurses by pregnant adolescents and adequacy of prenatal care was analyzed. Only one factor, age of baby's father, was found to be associated with adequacy of prenatal care.


The 'acting-out' adolescent: identification and management. The 'acting-out' adolescent presents both challenges and problems to the pediatric nurse who may not have the psychiatric skills necessary for managing negative behaviors that can interfere with both the adolescent's treatment and the overall functioning of the unit. Basic information is presented that will assist the pediatric nurse in the assessment and intervention of adolescents who present with problems manifested by behaviors related to anxiety, anger, hostility, and aggression.


Measles: again an epidemic.

Measles: again an epidemic. With the incidence of measles again on the rise in the United States, nurses have important roles in health promotion and education. Nurses and other health care providers need to be well informed about the potential severity of measles and the importance of immunization in preventing measles.


An overnight retreat to facilitate coping with stress. Stress is an ever-present part of nurses' work and personal lives. In an effort to facilitate coping with this stress, a diverse group of staff came together to plan what ended up being a unique and thoroughly beneficial experience.


Prevention of childhood injuries. Part I: Motor vehicle injuries. Unintentional (accidental) injuries are the leading cause of death in childhood and adolescence. In this article, interventions to reduce death and disability among children from motor vehicle injuries are identified. The major categories of injury are listed, the magnitude of the problem is defined, the risk factors are described, and selected interventions of the National Committee for Injury Prevention and Control are summarized. Recommendations for practice are discussed.


Cigarette, alcohol, and other drug use by school-age pregnant adolescents: prevalence, detection, and associated risk factors. Use of cigarettes, alcohol, and other drugs among pregnant adolescents is just beginning to be documented. This study sought to determine the prevalence and associated risk factors of cigarette, alcohol, and other drug use among school-age adolescents attending a comprehensive teenage pregnancy program. All enrollees completed a self-administered questionnaire and provided a breath sample for carbon monoxide analysis. Urine was obtained for quantitative determination of drug metabolites at the initial and one third-trimester visit. A chart review determined medical provider recognition of cigarette, alcohol, and other drug use. Results were analyzed for 93% of 229 eligible patients. Seventeen percent were positive for alcohol or other drug use by questionnaire self-report, provider report, or initial urine screen. Eleven percent were positive by urine screen alone at either the initial or third-trimester visit. Medical providers were successful in identifying nearly all of the cigarette smokers, but fewer than half of the alcohol drinkers and few of the other drug users. Forward stepwise multiple regression determined the most efficient model for predicting alcohol and other drug use. A report of having been high at school and personal or friends' use of cigarettes were the most significant risk factors. Results indicate a high prevalence of alcohol and other drug use and suggest a need for changes in current practice related to the detection and management of such drug use in pregnant adolescents.


Relationship between apnea and GER: what nurses need to know. Apnea and gastroesophageal reflux (GER) are both common occurrences in newborns and infants as well as in older children. There is a strong relationship between them. The correlation between GER as a cause of apnea has become increasingly clear over time. The extent to which they occur is an important subject for nurses in terms of recognition and intervention.


Parents' views of adolescent health issues. To determine how important the parents of teenagers consider adolescent health issues to be and the kind of involvement they would like from their schools and physicians, a questionnaire was sent to 1090 families with children attending two public high schools in a suburban community. The 438 parents who completed the questionnaire (40% response rate) indicated that their adolescents had a mean age of 16.2 years, 52% were male, 54% were in grades 11 and 12, and 70% received regular care from a pediatrician. Most parents considered substance use, sexuality, mental health issues, nutritional concerns, and general medical issues to be issues requiring attention nationally; many considered these issues to require attention locally; fewer considered these issues to require attention for their teenager's friends; and only some indicated these issues require attention for their own teenagers. More than 95% of respondents said parents should discuss these topics with their teenagers, more than 80% said they themselves did, and more than 85% said they wanted these issues discussed with their adolescents in school. Approximately three quarters of parents said that they would bring their adolescent to their regular doctor for management of these issues, expected that their physician would be comfortable with such care, and wanted their doctor to discuss these issues with their teenagers.(ABSTRACT TRUNCATED AT 250 WORDS)


Parent and infant attachment: review of nursing research 1981-1990. To determine what research information on attachment and bonding is available to nurses. A critical review was conducted for 26 studies on attachment and bonding published between 1981-1990. Studies had strength in their consideration of multiple factors hypothesized to influence attachment and bonding. However, methodological concerns are raised about validity of designs and tools. Nurses involved in clinical practice and research would benefit by clarifying their conceptions of attachment and bonding. Nurses can broaden their assessment base, including fathers' as well as mothers' perspectives, verbal and nonverbal behaviors, cultural differences, and interchange in the parent-infant relationship.


Maternal smoking and behavior problems of children. Numerous health consequences of children's exposure to maternal smoking have been demonstrated, including increased rates of low birth weight, infant mortality, respiratory infections, asthma, and modest impairments of cognitive development. There is little evidence, however, linking maternal smoking and increased rates of children's behavior problems. Data from the population-based National Longitudinal Survey of Youth were used to investigate the possible association of maternal smoking and behavior problems among 2256 children aged 4 through 11 years. In multiple regression analyses the authors controlled for child's race, age, sex, birth weight, and chronic asthma; family structure, income, and divorce or separation in the prior 2 years; mother's education, intelligence, self-esteem, employment status, chronic disabling health conditions, and use of alcohol during pregnancy; and the quality of the home environment as assessed by the Home Observation for Measurement of the Environment-Short Form to investigate the relationship between maternal smoking and children's behavior problems. The measure of maternal smoking status reflected two levels of smoking intensity (less than a pack per day and a pack or more per day) for each of three different categories of children's exposure: prenatal only (mother smoked only during pregnancy), passive only (mother smoked only after pregnancy), and prenatal plus passive exposure (mother smoked both during and after pregnancy). Measures of children's behavior problems included the overall score on a 32-item parent-reported child Behavior Problem Index (PBI), scores on the BPI's subscales, and rates of extreme scores on the BPI.(ABSTRACT TRUNCATED AT 250 WORDS)


Chest pain in otherwise healthy children and adolescents is frequently caused by exercise-induced asthma. Chest pain in children and adolescents, unlike in adults, is rarely of cardiac origin and its etiology is frequently unknown. In this age group, chest pain can limit normal activity and sports participation. The reported incidence of exercise-induced asthma in children with chest pain is less than 20%. For this study, 88 otherwise healthy children and adolescents with chest pain followed a treadmill protocol without a warm-up period designed to obtain a target heart rate of 180 or greater during the first several minutes of exercise. Patients maintained this workload for 6 to 8 minutes. Pulmonary function tests performed prior to exercise and at 2, 5, 10, 15, 20, and 25 minutes revealed a decrease in forced expiratory volume in 1 second or peak expiratory flow rate of greater than or equal to 15% in 64 (72.7%) children. Inhaled albuterol resulted in subjective improvement in 97% (35/36) and objective improvement in 70% (25/36) of patients. In otherwise healthy children and adolescents with chest pain, the incidence of exercise-induced asthma seems greater than previously reported. Treatment with bronchodilators may help these patients lead a more active life-style.


Acetaminophen and ibuprofen: fever control and overdose. Fever has been recognized as a sign of disease for centuries. Health care professionals and parents frequently search for new methods of pediatric fever control. Current research suggests that prostaglandins play an important role in fever production. As antipyretics, both acetaminophen and ibuprofen are effective in fever reduction by inhibiting prostaglandin synthesis. In this article, the pathophysiology of fever is discussed as a foundation for understanding fever management. The metabolic pathways of both agents are compared as they relate to fever control; the common side effects and nursing management for acute overdoses are discussed.


Correlates of children's bicycle helmet use and short-term failure of school-level interventions. To test the utility of school-level interventions for child bicycle safety and to identify social and behavioral factors associated with children's bicycle helmet use, a two-level intervention was conducted in two suburban elementary schools. Children (N = 209) and parents (N = 125) in school 1 and in school 2 (children, N = 470; parents, N = 364) were surveyed regarding bicycle injuries and helmet use. Children and parents in schools 1 and 2 received literature about bicycle safety and discount coupons for helmet purchase. School 1 was then the target of an intensive safety campaign, including meetings with the school safety committee and the PTA and a classroom presentation to children emphasizing helmet use. Ten months later the same survey was again administered. Children in school 1 were more likely at posttest to believe that helmets were protective (P = .003) but did not differ on other variables. Logistic regression showed that sibling helmet ownership, parental helmet use, and lower parental perceived social barriers to helmet use were independently associated with children's reported helmet use and with parental intent for the child to use a helmet at posttest.


Above and below the threshold: severity of psychiatric symptoms and functional impairment in a pediatric sample. Pediatricians are sufficiently concerned about the importance of "subthreshold" mental health problems to have joined in the movement to create a Diagnostic and Statistical Manual of Mental Disorders for the primary care setting (DSM-PC), with the aim of establishing a set of criteria for disorders that do not meet the severity requirements of the American Psychiatric Association's current DSM. An element in the argument for a DSM-PC is that there is a high level of functional impairment and need for treatment in children with mental health problems below the DSM threshold. This was examined in 789 children aged 7 through 11 recruited sequentially from the pediatric clinics of a health maintenance organization, compared with 134 age-matched children seen in a psychiatric clinic. Of the pediatric patients, 22% had one or more clinical-level DSM-III diagnoses, and 42% had a threshold-level disorder, compared with 65% and 34%, respectively, of psychiatric patients. In the pediatric sample, most threshold, and all clinical-level disruptive behavior disorders were associated with significant levels of functional impairment. There was little evidence that emotional disorders (anxiety and depression), even at the clinical level, were associated with significant impairment. One implication of these results is that pediatricians can expect one child in five to have a clinical-level DSM disorder. A second is that intervention at low levels of disruptive behavioral symptomatology may be needed if significant functional impairment is to be avoided.


Mother-to-child transmission of human immunodeficiency virus type 1: risk of infection and correlates of transmission. One thousand eight hundred eighty-seven children born to human immunodeficiency virus type 1 (HIV-1) seropositive mothers, including 1045 infants prospectively followed up from birth, were studied. Intravenous drug use was the most frequent maternal risk factor, although the percentage of women infected by sexual contact increased from 5.8% in 1985 to 28.5% in 1990. Of the 551 first children followed up from birth and older than 15 months of age, 101 (18.3%) acquired infection and seroconverted to HIV-1. Another 31 (5.6%) asymptomatic seronegative children showed the presence of viral markers, for an apparent mother-to-offspring transmission rate of 23.9%. Overlapping results were seen in 22 second-born children followed up from birth. Of 59 sibships with definite infection status, when the first child was infected, 14 (40%) of 35 second children were infected, whereas when the first child was not infected, only 2 of 24 (8.3%) second children were infected. Discordance in HIV-1 transmission was found in 1 of 18 pairs of twins. Univariate and multivariate analyses of possible risk factors for HIV-1 transmission performed on the entire population of children and in the cohort of those followed up from birth were basically in agreement in indicating that the development of symptoms in the mother before delivery and breast-feeding (indeed adopted in only 22 infants in whom HIV-1 infection was identified at birth) were significantly and independently associated with a higher transmission rate. In addition, girls were more frequently infected than boys.(ABSTRACT TRUNCATED AT 250 WORDS)


Iron status in exclusively breast-fed infants. The aim of this study is to evaluate the iron nutritional status of infants breast-fed exclusively and for a prolonged period in relation to their growth rate and dietary changes. Forty subjects (25 breast-fed; 15 formula-fed) were studied from 0 to 9 months of age. Milk (human or formula) was the only source of food during the first 6 months. From the sixth month onward mothers were instructed to use iron- and ascorbic acid-rich foods to supplement breast-feeding. At the ninth month, prevalence of anemia was 27.8% in the breast-fed group and 7.1% in the formula-fed group. Storage iron was absent in 27.8% of the breast-fed infants vs none of the formula-fed infants. These findings reinforce the recommendation that breast-fed infants be given supplemental iron from the fourth month of life.


Oxygen desaturation complicates feeding in infants with bronchopulmonary dysplasia after discharge. Recurrent episodes of hypoxemia may affect the growth, cardiac function, neurologic outcome, and survival of infants with bronchopulmonary dysplasia (BPD). As oral feeding might stress these infants by compromising pulmonary function even after hospital discharge, we measured oxygen saturation (SaO2) via pulse oximetry before, during the initial 10 minutes of, and immediately after oral feeding in 11 patients with BPD, 12 very low birth weight infants, and 23 healthy full-term infants. All infants with BPD had been previously discharged from the hospital after weaning from supplemental oxygen. Studies were done at a mean postconceptional age of 43 weeks while the infants were fed at home by one of their parents. Levels of SaO2 for the three groups were comparable before and during feeds. After feeding, the infants with BPD had significantly lower mean levels of SaO2 (84 +/- 8% [SD] vs 93 +/- 4% and 93 +/- 3%, respectively; P less than .01). They also spent more time after feeding with an SaO2 less than 90% (64 +/- 34% of time vs 27 +/- 33% for the very low birth weight and 22 +/- 20% for the term group; P less than .01) and greater time with an SaO2 less than 80% (37 +/- 28% vs 4 +/- 10% and 4 +/- 8%, respectively; P less than .01). Desaturation in infants with BPD was related to larger volume and faster oral intake during feeding. Thus, the data indicate that desaturation after feeding remains a recurrent problem for survivors of BPD after discharge.(ABSTRACT TRUNCATED AT 250 WORDS)


Potential role of intrapulmonary shunting in the genesis of hypoxemic episodes in infants and young children. A number of physiologic phenomena during some apneic/cyanotic episodes in infants and young children cannot be explained sufficiently on the basis of a cessation or reduction in alveolar ventilation alone. These include (1) the extremely rapid development of hypoxemia during some episodes, (2) the occurrence of hypoxemic episodes despite continuous ventilation, (3) differences in the speed of desaturation between different forms of apneic episodes, (4) the presence of continued breathing efforts and yet absent airflow despite bypass of the upper airway, and (5) evidence that apnea and hypoxemia may begin simultaneously. Potential mechanisms to explain these phenomena include the sudden development of an unevenness in the matching between ventilation and lung perfusion, the flow of blood through unventilated areas of lung, and a sudden impairment in gas diffusion. Evidence from physiological and morphological studies suggests that all of these mechanisms, although to a different extent, may be involved in apneic/cyanotic episodes. The recognition that nonapneic mechanisms can cause sudden profound hypoxemia may alter our approach to the identification, treatment, and prevention of these episodes.


Hearing and neurodevelopmental outcome in survivors of persistent pulmonary hypertension of the newborn. Thirty-four infants who had a diagnosis of severe persistent pulmonary hypertension of the newborn at birth (alveolar-arterial oxygen difference greater than 600) were treated without paralysis or hyperventilation to induce alkalosis. All survived. Twenty-seven of these 34 eligible infants (79%) underwent neurologic, intelligence, and audiologic testing between 10 months and 6 years of age. Children who were younger than 1 year of age at the initial hearing test were retested after they reached 2 years of age. The average IQ was within the normal range (mean = 96.23). None had sensorineural hearing loss. Severe neurologic abnormalities were seen in 4 children, 3 of whom had been severely asphyxiated at birth (determined by biochemical criteria). Mild neurologic abnormalities were observed in 5 children. Two infants had bronchopulmonary dysplasia because they required supplemental oxygen for 29 and 66 days, respectively, and had abnormal chest roentgenograms; 1 patient takes intermittent doses of albuterol (Ventolin) and neither currently requires supplemental oxygen. This study of 27 infants with severe persistent pulmonary hypertension of the newborn suggests that conservative management without induced alkalosis or respiratory paralysis is accompanied by no sensorineural hearing loss and a good neurologic outcome.


Clinical diagnosis and management of respiratory distress in preterm neonates: effect of participation in a controlled trial. The ability to generalize the results of a clinical trial depends on the ability to compare a population of patients with the population described in the trial, emphasizing the importance of objective diagnostic criteria in study design and clinical medicine. However, clinical decisions are often based on subjective interpretations of data. There is concern that bias that an experimental therapy is beneficial might lead to alterations in clinical diagnosis and management. To evaluate this concern, the authors reviewed a preexisting database comprising information obtained by trained personnel by chart review to investigate prospectively the frequency of the diagnosis of hyaline membrane disease and the use of mechanical ventilation before and during participation in a clinical trial of surfactant therapy during which such therapy was available exclusively through clinical trials. Major eligibility criteria for a randomized trial at the Medical University of South Carolina included mechanical ventilation and the diagnosis of hyaline membrane disease. Both the diagnosis of hyaline membrane disease and the use of mechanical ventilation increased between pre-surfactant and randomized trial periods (hyaline: 47.2% to 55.9%, P less than .05; ventilation: 55.6% to 66.3%, P less than .01). The possibility that enthusiasm for surfactant influenced clinical diagnosis and management of respiratory distress during this period cannot be dismissed.