Expulsion of Nippostrongylus brasiliensis from mice lacking antibody production potential. Expulsion of the intestinal nematode of rodents, Nippostrongylus brasiliensis, was assessed in mice experiencing the immunosuppressive effects of anti-micron antibodies. Anti-micron treatment resulted in complete elimination of IgM and severe reduction of IgG1, IgG2 and IgA serum immunoglobulin levels. Specific antibody responses to sheep erythrocytes were virtually eliminated in anti-micron-treated mice as determined by direct and indirect plaque-forming-cell responses, haemagglutination and haemolytic assays. Using passive cutaneous anaphylaxis (PCA) and indirect haemagglutination (IHA) assays, antibodies against N. brasiliensis were not detectable in sera of anti-micron-treated mice; control mice, however, generated strong PCA and IHA responses. The kinetics of worm egg production coupled with adult worm recoveries at necropsy indicate that anti-micron treatment of mice had little or no effect on the capacity of mice to expel N. brasiliensis even though antibody production potential had been eliminated in these mice. Thus, anti-worm antibodies may not be requisite in the mechanism of N. brasiliensis expulsion from mice.


Presence and production of migration inhibitory activity in the peritoneal cavity. The presence of migration inhibitory (MI) activity was investigated in the delayed hypersensitivity (DH) reaction induced by i.p. injection of PPD into FCA-sensitized guinea-pigs. Peritoneal exudates were studied at several times before and after the induction of the DH reaction and a non-immune control inflammation. Lymphokine (LK) fractions were prepared from individual exudates and tested in a conventional macrophage migration inhibition assay at concentrations determined to occur in vivo. The results suggest a continuous local production of MI activity and an augmented production during development of a DH reaction.


Characterization of the direct effects of cyclophosphamide on cell-mediated immunological responses. The direct immunosuppressive effects of cyclophosphamide were examined by incubating normal guinea-pig mononuclear cells with activated cyclophosphamide prepared from the serum of separate animals which were treated with cyclophosphamide in vivo. Treated cells were subsequently assayed in a panel of tests of cell-mediated immunity either immediately or following recovery during variable periods of incubation. It was found that cyclophosphamide (1) induces changes in lymphocyte functions which are not due simply to cell death; (2) is markedly antiproliferative in mitogen-induced blastogenesis; (3) depresses migration inhibitory factor production only after a delay of several hours and (4) depresses certain cytotoxicity reactions immediately following treatment, such responses are subsequently normalized when the cells are allowed to recover in culture.


Immunoglobulin class and subclass levels in the serum of CBA mice throughout life. The levels of IgA, IgM, and the four subclasses of IgG in the serum of CBA mice of different ages were measured by the Sepharose bead immunofluorescence assay. The developmental curves of the CBA serum levels indicate three periods in the life of the mice during which changes occur. The respective adult levels of the different Ig's are reached during the first 6 months. Between 6 and 24 months of age, individual class and subclass levels do not show much change, except for the IgG1 and IgG2b subclasses, which clearly increase. The last period, from 24 months on, is characterized by great variation among the Ig levels of individual animals, while the mean levels do not show distinct trends. Although some differences between the levels of Ig's of female and male mice were observed at certain ages and for certain Ig's, no systematic trend was clear. The generally recognized age-related decline in immunocompetence is thus not accompanied by decreasing levels of serum immunoglobulins.


Complement activation by the alternative pathway and macrophage enzyme secretion in the pathogenesis of chronic inflammation. A number of stimuli known to induce acid hydrolase secretion from cultured macrophages were examined for their ability to activate C3 via the alternative pathway of the complement system. Loss of haemolytically active C3 was checked in normal and C4-deficient guinea-pig serum. For comparison the interactions of cultured macrophages with other agents well known as potent activators of the alternative pathway of the complement system have been investigated. As judged by their activity in these assays, group A streptococcal cell walls, different carrageenan preparations, dental plaque and Actinomyces viscosus were all capable of initiating the alternative pathway but differed with respect to their potency and their ability to inhibit C3 turnover at high concentrations. Zymosan, some carrageenans, polyanethol sulphonate, and Corynebacterium parvum all induce the release of hydrolytic enzymes from macrophages in culture, even in the absence of serum in the medium. The release is time- and dose-dependent and is not associated with loss of the cytoplasmic enzyme lactate dehydrogenase or any other sign of cell death. The parallelism between the capacity of several agents to activate the complement system via the alternative pathway and to induce inflammatory responses in vivo and selective lysosoma enzyme secretion from cultures of macrophages is discussed.


The role of Fc and C3b receptors in phagocytosis by inflammatory polymorphonuclear leucocytes in man. Polymorphonuclear leucocytes from the gingival crevice (CREV-PMN) in man have a defective capacity to phagocytose Candida albicans blastospores. Phagocytosis of zymosan particles, which detect C3b receptors, is also impaired but ingestion of latex beads coated with heat-aggregated IgG, which detects Fc receptors, is normal compared to peripheral blood polymorphonuclear leucocytes (PB-PMN). If phagocytosis is inhibited by Cytochalasin B, fewer CREV-PMN bind Candida and zymosan but the binding of IgG-coated latex beads remains unchanged. CREV-PMN have IgG (88%), IgM (45%) and C3 (48%) on their cell membrane, whilst less than 5% of PB-PMN have any of these components. Incubation of PB-PMN in fluid from the gingival crevice confers surface IgG and C3 to the cells. Such treatment also inhibits the subsequent binding of IgG coated latex beads. The results suggest that the deficiency of phagocytosis by CREV-PMN is due to decreased binding of particles to the C3b receptor of PMN, whilst the Fc receptor system remains intact.


Dextran sulphate: an adjuvant for cell-mediated immune responses. The effect of high mol. wt dextran sulphate (DS) on cell-mediated immune responses was studied. Three criteria were used to assess cell-mediated delayed-type hypersensitivity: footpad swelling, i.d. skin tests and macrophage migration inhibitory factor (MIF) production. Guinea-pigs sensitized with egg albumin (EA) and treated with DS showed strong positive delayed skin tests. Control animals given only EA showed negative skin tests. Lymphocytes from mice sensitized s.c. with EA and treated with DS showed an increase in MIF production. Delayed footpad swelling responses in mice sensitized s.c. with sheep red blood cells (SRBC) and treated with DS were increased when the mice were challenged 8 days after sensitization. Doses of DS which were effective in increasing delayed footpad swelling ranged from 50-200 mg DS/kg body weight. DS was only capable of increasing delayed footpad swelling responses when both SRBC and DS were injected s.c. at the same site. Intraperitoneal injection of both SRBC and DS obeebction of both s.c. but at different sites did not result in increased delayed footpad swelling. DS was capable of augmenting footpad swelling responses when given s.c. as much as 6 days before SRBC. The optimal time for administration of DS was 2 days before SRBC. Injection of DS 2 days or more after SRBC resulted in no increase in delayed footpad swelling responses. The results of this study indicate that dextran sulphate is a potent adjuvant for cell-mediated delayed-type hypersensitivity immune responses in both mice and guinea-pigs.


Nocardia water-soluble mitogen and lipopolysaccharide. Comparative study of two adjuvants and B-cell mitogens in mice. The activity of Nocardia water-soluble mitogen (NWSM) and LPS were compared in several experimental systems, since both compounds are B-cell mitogens and polyclonal activators in vitro. The results reported here demonstrated that NWSM like LPS also has a strong adjuvant activity in vivo if administered in saline with a strong antigen (heterologous red blood cells) or even with a weak immunogen such as theta alloantigen. However, in contrast to LPS, NWSM administered to mice failed to induce in vivo proliferation of lymphocytes, polyclonal activation and PFC against syngeneic bromelain-treated erythrocytes and thymocytes. It is possible therefore, that different mechanisms may be responsible for adjuvant activity of NWSM and LPS.


Vascular changes in flexor tendons after injury and repair: an experimental study. Two groups of experiments were carried out on the profundus tendons of New Zealand rabbits: 1. Simple closed tenotomies at various levels along the digit. 2. Open tendon division followed by repair with a Bunnell criss-cross suture. At intervals after the operation injection studies were performed to outline the vascular pattern within the tendons. The results indicate that the circulation through the intratendinous vessels is precarious and it may be impaired both by tenotomy and by the presence of sutures. It is suggested that this may be an important factor in the pathogenesis of adhesions. The clinical implications are discussed.


Patterns of loss of enterotoxigenicity by Escherichia coli isolated from adults with diarrhea: suggestive evidence for an interrelationship with serotype. Enterotoxigenic Escherichia coli isolates obtained in Mexico from adult subjects with diarrhea and from healthy controls were examined for the production of heat-stable enterotoxin (ST) and heat-labile enterotoxin (LT) after serial passage in the laboratory. Isolates were found to be either stable for the production of ST and LT or unstable with respect to ST, LT, or both. Unilateral loss of either ST or LT production allowed classification of E. coli isolates into four groups according to stability/instability of enterotoxin production. Fewer serotypes, with more representative isolates, were in group I (stable) than in group IV (completely unstable). Isolates from Dacca, Bangladesh, could be similarly classified into stability groups. There is an apparent relationship between serotype, stability of enterotoxin production, particularly LT, and isolation from diarrhea cases as opposed to isolation from healthy controls.


Experimental Candida albicans endocarditis: characterization of the disease and response to therapy. Endocarditis caused by Candida albicans was induced in rabbits after insertion of a catheter across the aortic valve. The mean survival time of 34 rabbits was 26 days. Only 7% of temperature recordings taken were elevated. Candida was recovered from only 9% of blood cultures taken. Precipitating and agglutinating serum antibody was detected after 12 days of infection. Antibody titers rose progressively until death in rabbits with endocarditis, whereas titers peaked early and subsequently decreased in animals that received an intravenous injection of C. albicans without precatheterization. Three groups of rabbits were treated for 6 days with amphotericin B, 5-fluorocytosine, or the two durgs in combination. Amphotericin B alone reduced the mean titer of organisms from log10 8.79 +/- 1.46 to log 10 3.1 +/- 1.9 colony-forming units/g. 5-Fluorocytosine was less effective (mean titer after 6 days of therapy was log10 7.4 +/- 0.33 colony-forming units/g). The addition of 5-fluorocytosine to amphotericin B did not increase the rate at which Candida cells were eradicated from the vegetations. These in vivo results corrleated with the failure to demonstrate an increased rate of fungicidal activity in vitro with the two drugs.


Parasitism by virulent Treponema pallidum of host cell surfaces. The interaction between virulent Treponema pallidum extracted from infected rabbit testes and animal cells in culture was examined. The extent of treponemal attachment to monolayers of normal rabbit testicular and HEp-2 cells was dependent upon the incubation temperature and retained motility of the spirochetes. The specific orientation of treponemes to host cell surfaces was demonstrated by dark-field microscopic examination of wet-mount preparations and scanning and transmission electron microscopy. Once attached, T. pallidum organisms remained actively motile yet anchored in place by their terminal tapered structures. After several hours of co-incubation, maximal attachment was attained, and the degree of parasitism seemed regulated not only by available surface sites on individual host cells but also by the proposed membrane response of parasitized cells to continued exposure to treponemes. The avirulent strain, Treponema phagedenis biotype Reiter, did not adhere to monolayer cultures. Characterization of host cell determinants that permitted surface colonization by T. pallidum was attempted. Also, properties of virulent treponemes that enabled surface parasitism were monitored by measuring the effects of enzymes, detergents, and metabolic inhibitors on the host-parasite interaction. Results reinforced the specific nature of the treponemal attachment mechanism. Furthermore, the ability of convalescent rabbit sera to reduce attachment of treponemes to host cells suggested that surface structures on T. pallidum could be masked or inactivated by host components, thus providing a potentially effective research approach for investigating the pathogenesis of syphilis and screening appropriate vaccine candidates.


Immunogenic cross-reactivity between human tissues and the enterobacterial common antigen. Sterile tissues of human subjects free from infection and malignancy were assessed for an antigen that cross-reacts with the enterobacterial common antigen (ECA). Extracts of heated homogenates (HE) and ethanol-soluble (ES) fractions of liver, kidney, muscle, and heart tissues were examined for their capacities to react with ECA antibodies, as measured by hemagglutination procedures, and to elicit ECA humoral antibodies in rabbits. Both HE and ES extracts of human liver and kidney tissues specifically inhibited ECA hemagglutination. However, ES fractions of HE preparations demonstrated significantly greater inhibiton than their HE sources. In addition, both liver and kidney ES fractions primed rabbits for a rapid and specific secondary ECA humoral response to a single administration of ECA. The cross-reactivity noted between human tissue and ECA cannot be attributed to indigenous microorganisms present in the tissues, as subcultures of tissue homogenates were always sterile. Moreover, preliminary experiments with human fetal subjects, devoid of microbial flora, yielded similar results.


Rough mutant of Shigella flexneri 2a that penetrates tissue culture cells but does not evoke keratoconjunctivitis in guinea pigs. A rough mutant, designated 5503-01, has been isolated from a virulent strain of Shigella flexneri 2a 5503. Strain 5503-01 produced smooth opaque colonies, whereas its parent strain produced characteristic green-gold translucent ones. Characterization of 5503-01 by agglutination tests, rhamnose content, and sensitivity spectra to "rough-specific" phages revealed that it had lost the specific somatic antigens. When 5503-01 was used to infect HeLa or L cells, it penetrated the cells and multiplied within the cytoplasm. On the other hand, it could not evoke keratoconjunctivitis in guinea pigs. The properties of this strain were remarkably stable against serial passages and preservation for a long period. The presence of a rough mutant with the ability to penetrate tissue culture cells suggest that specific O antigen is not of significance in the early step of the invasive process of shigellosis.


Diarrhea caused by Escherichia coli that produce only heat-stable enterotoxin. To determine the role of Escherichia coli heat-stable enterotoxin (ST) as a virulence factor in human diarrhea, a strain that elaborates only ST (E. coli 214-4) was fed to free-living volunteers in doses of 10(6), 10(8), and 10(10) organisms. Short-lived (1 day) mild illness consisting of abdominal cramps with vomiting or diarrhea occurred in three of five individuals fed 10(8). Typical travelers' diarrhea (loose stools, abdominal cramps, and low-grade fever for 2 to 3 days) was seen in four of five volunteers given 10(10); two had brief cholera-like purging of rice-water stools. Despite fever, there was no evidence of mucosal invasion. E. coli 214-4 became the predominant coliform in stools; coproculture isolates were uniformly negative for heat-labile enterotoxin (LT), whereas most produced ST. Ten of 13 individuals developed rises in antibody to somatic E. coli antigen, and none had rises in LT antitoxin. E. coli that elaborate only ST can cause diarrheal disease in adults.


Effect of neonatal gastrointestinal colonization with cross reacting Escherichia coli on anticapsular antibody production and bacteremia in experimental Haemophilus influenzae type b disease of rats. Neonatal gastrointestinal colonization of newborn rats with Escherichia coli 075:K100:H5, cross-reactive with the capsular polysaccharide of Haemophilus influenzae type b, was harmless but failed to stimulated detectable ( greater than 200 ng/ml) serum anticapsular antibodies. Neonatally colonized rats, when challenged at age 13 weeks by intraperitoneal inoculation of H. influenzae b, showed no difference in the frequency, magnitude, or duration of bacteremia or in the postinfection anticapsular antibody response when compared with saline-fed controls. However, neonatally colonized rats challenged at age 4 weeks had a significantly decreased incidence of sustained bacteremia and/or endophthalmitis when compared with controls. This decreased frequency of disease correlated with a significant increase in postinfection serum anticapsular antibodies. Neonatal gastrointestinal colonization with cross-reacting E. coli appears to "prime" the young host to respond to infection with H. influenzae b with an anticapsular antibody response that protects against sustained H. influenzae b bacteremia and its complications.


Role of endotoxin contamination in ribiosomal vaccines prepared from Salmonella typhimurium. Ribosomal vaccines prepared from Salmonella typhimurium SR-11 and 6707 an Re mutant bacterium of strain LT2, were effective immunogens in A/J and C3H/HeDub inbred mice. Only SR-11 ribosomes were able to induce significant protection in C3H/HeJ mice. C57BL/6J mice were not protected by either ribosomal preparation. A/J mice were protected against salmonella infection by purified SR-11 endotoxin preparations. Neither the C3H/HeDub, the C3H/HeJ, nor the C57BL/6J mice were protected by the endotoxin preparation. Passive hemagglutination studies showed that C3H/HeJ mice had no antibodies to O antigen but were significantly protected by SR-11 ribosomes. In contrast, C57BL/6J mice, which had the highest titers of O antibodies of the four inbred mouse strains, were not protected by SR-11 ribosomes. Endotoxin cannot totally  account for the effectiveness fo ribosomal account for the effectiveness of ribosomal vaccines prepared from S. typhimurium.


Isolation of mycoplasma species from infertile patients: an epidemiological contribution. In this study the presence of Mycoplasma species in patients suffering from infertility was examined. 41 women and 37 men were examined, including 31 couples, and ten single women and six single men. Samples of vaginal and cervical mucus were taken from each woman, and samples of seminal fluid from each man. Identification and typing of the organisms were performed on the basis of microscopic and cultural characteristics and inhibition of growth by specific antibodies. Out of the 78 patients examined, 35 harboured Mycoplasma, either as Ureaplasma urealyticum or Mycoplasma hominis. Further investigation is needed to determine the clinical significance of these findings.


Controlled clinical trials in periodontal disease by general practitioners. The general practitioner with loyal and regular patients is in a good position to undertake long-term clinical trials of periodontal treatment. Ethically, these should be comparisons of agents or procedures acknowledged to be beneficial but lacking confirmation of the long-term effects. Standardized bite-wing radiographs can represent a valuable record in this type of study.


Critical discussion of previous experience and new approaches in the development of composite filling materials. Following the 1975 report in Chicago, an attempt is made to discover the present position with regard to the development of composite filling materials, and to determine whether further development is necessary or even possible. The reasons for considering clinical trials important are given, and the problem of the chemical bond to hard dental tissues is discussed. The influence of the thermal coefficient of expansion on the marginal seal is discussed in relation to border discolouration, and a critical assessment given of acid etching and remineralization. The significance of wear for the maintenance of contours is pointed out, in particular in connection with occlusal surface fillings in the cheek teeth, as well as the problem of contact-point characterization and fracture strength after repair of an old filling. Improvements in UV light polymerization are described. A critical discussion of the different opinions on the significance of histological findings in relation to pulp tolerance is presented, and finally the significance of water uptake and radiological opacity is discussed. In conclusion indications in relation to the present state of development are listed.


Surgery of the alveolar process as related to prosthesis. The healing of an extraction wound is taken as starting-point, and complications and their avoidance are discussed insofar as they affect the shape of the alveolar process. Surgical methods of treating cysts and other tumours are reviewed, and it is shown how these may be carried out with little damage to the form of the denture-base. Every dentist should bear in mind subsequent prosthetic care whenever undertaking surgery of the oral cavity.


The impression tray--an important factor in impression precision. The flow behaviour of impression materials during impression taking was first investigated, and reference made to the pressure which occurs in the compound. Individual trays of plastic and shellac-bases which could be softened by heating, and a cold-curing tray material were then also examined: (1) for their distortion by slight loads upon the tray walls; (2) for their ability to retain their shape when stored, and (3) their distortion when temporarily warmed to body temperature. It was found that no tray materials, although graded according to type and thickness, can be considered rigid under experimental conditions, since distortions which were in some cases considerable could be measured. In laboratory experiments, the behaviour of the tray was then measured while taking impressions of models and the precision of the impression was examined at the same time. This confirmed the suspicion that the precision of an impression is to a considerable extent related to the tray material used. The smallest alterations were found when using cold-curing plastic material of a sufficient thickness (greater than 2 mm).


Expermental glomerulonephritis in the rat induced by antibodies directed against tubular antigens. III. In vitro evaluation of cell-mediated immune responses against immune complexes influenced by immunosuppressive therapy. In this paper, cell-mediated immunity (CMI) as evaluated by in vitro migration inhibition assays an in vivo delayed type skin reactions in experimental immune complex glomerulonephritis (ECGN) was studied as well as the effect of treatment with immunosuppressive drugs on these immune responses. In glomerulonephritic rats MIF production as well as delayed type skin reactions could be demonstrated directed against tubular brushborder antigen (Fx1A) containing immune complexes or to their constituents (FX1A or rabbit IgG). Treatment of the animals with immunosuppressive drugs during settled disease state (autologous phase) abolished these cellular immune reactions. However, neither the glomerular depositions of rat IgG associated with the autologous phase, nor the urinary excretion was influenced. When treatment of the animals was started simultaneously with the induction of the ECGN both cellular and humoral immune responses as well as proteinuria were affected. It was concluded that although in this glomerulonephritis model specific MIF response after specific stimulation in vitro as well as DTH reactions could be detected against immune complexes or their constituents, these immune reactions seem not to play important role in this ECGN in particular with respect to the proteinuria.


Suppression of cell-mediated immunity by metronidazole. Metronidazole administered orally in doses of 20 and 200 mg/kg daily suppressed granuloma formation around Schistosoma mansoni eggs which were injected intravenously and lodged in the pulmonary microvasculature of mice. The same doses did not suppress granuloma formation in animals which had previously been sensitized to the eggs. Nonspecific granulomatous inflammation around divinyl benzene copolymer beads was unaffected by the drug. In a daily dose of 20 mg/kg, metronidazole inhibited delayed footpad reactions to soluble schistosome egg antigen, but 200 mg/kg on alternate days failed to suppress skin allograft rejection. The drug appears to suppress selectively some aspects of cell-mediated immunity.


Cell-bound IgE on human mast cells and basophilic granulocytes in atopic and nonatopic subjects. In previous studies basophil-bound IgE was measured by means of quantitative immunofluorescence miscroscopy. But mast cells are of particular importance in local atopic reactions, we thought it necessary to investigate the IgE-load on both cell types. The amount of mast cell-bound IgE can be estimated in a semiquantitative way by end point titration with a fluoresceinated sheep antihuman IgE (FlaIgE). The amount of mast cell-bound IgE was estimated this way in tonsils, adenoids, bronchial and tracheal tissues, and was compared with the amount of IgE on the basophils. A correlation was found between the IgE-load on mast cells and on basophils. Atopic patients had a higher mast cell fluorescence titer (MCFT) than nonatopic controls. It was demonstrated that, as on basophils, the IgE level of the serum contributes to this difference.


Observations on rosette formation by thymocytes and T lymphocytes in guinea pigs. Effect of neonatal thymectomy, irradiation, thymosin, albumin and the influence of cell viability. Irradiation (300 rad) of guinea pigs and subsequent transfer of bone marrow cells was followed by a decreased frequency of rabbit erythrocyte rosettes (a T lymphocyte marker) in peripheral lymphoid organs. Neonatal thymectomy did not potentiate this effect. A reduced amount of rosette-forming cells was also found in the thymus of irradiated animals. This was not affected by treatment with thymosin in vivo or in vitro, and was probably due to a reduced viability of the cells after irradiation since it was demonstrated that rosette formation among dead thymus cells was significantly less than among living cells. Incubation of normal thymocytes in non-supplemented medium for 2--4 h at 37 degrees C was also followed by a diminished rosette-forming capacity. The addition of thymosin or bovine serum albumin prevented both the decrease of rosette-forming cells and the reduction of viable cells during incubation. Thus, a diminished rosette formation may have been caused by reduced viability after incubation as well as after irradiation. The rosette-forming ability of only some dead thymocytes may reflect different subpopulations.


Electron microscopic studies on human basophils from atopic and nonatopic subjects, using horse radish peroxidase labelled anti-IgE. In previous studies, quantitative differences in cell-bound IgE on the basophils from various donors were measured by means of a quantitative immunofluorescence technique. In this study, cell-bound IgE was demonstrated on basophilic granulocytes by immunoelectron microscopy, using horse radish peroxidase labelled anti-IgE. The distribution of IgE on the basophils was studied in both atopic and nonatopic subjects. The intensity of the peroxidase staining on the basophils varied and appeared to correlate with the amount of cell-bound IgE, as estimated by quantitative immunofluorescence.


Computer simulation of medical reasoning in the assessment of kidney disease. A system for the simulation of clinical reasoning was applied to the evaluation of patient data in nephrological diseases. The system allows the physician to computerise the medical logic in his area of specialisation, to prepare suitable protocols for recording clinical observations, to analyse the patient data for assessing his present clinical status and to plan appropriate diagnostic and therapeutic interventions. The medical logic is expressed in modular form as a series of inferences to be confirmed or rejected on the basis of Boolean combinations of clinical findings and previous inferences. The acceptable Boolean combinations are formulated in terms of threshold logic. The computer programs produce alphabetical lists of the clinical findings appearing in the medical logic, which are organised by the physician into data acquisition protocols appropriate to each phase of clinical activity. The system was run on a series of 22 patients hospitalised in the Department of Nephrology. The patient status reports produced by the computer were in substantial agreement with the assessment of a senior nephrologist. The protocols assured a more complete and accurate recording of patient data than that appearing in the routine patient chart. The program was of value in standardising patient examinations and in the training of new medical staff.


The medical "brain drain" and health priorities in Latin America. This analysis of the medical brain drain places the problem in the context of the health care infrastructure in the developing world. It emphasizes Latin American social realities as a corrective to the self-interest which characterizes much of the current debate in the United States. It is argued that the same factors constituting emigration "push" factors in Latin America simultaneously underscore the relative unimportance of medical manpower migration compared to other obstacles to health progress. That conclusion is supported by a comparison of the relative damage caused by the brain drain by itself and the damage caused by factors which the brain drain concomitantly symbolizes and flows from: elitist objectives, misdirected priorities, unrealistic policies, and inadequate planning on the part of most Latin American nations. In the absence of urgently needed change in traditional structures, merely closing the gates on foreign medical graduates will not serve to ameliorate health conditions in the region. Those who seek real health improvements for developing nations must address greater challenges than the brain drain.


The effect of alternate-day prednisone therapy on cortisol secretion rate in corticosteroid-dependent asthmatics. The effect of alternate-day prednisone regimen (nine-patients) on cortisol secretion rate was compared with daily therapeutic regimen (ten patients) in corticosteroid-dependent asthmatics. Only the alternate-day regimen did  not suppress the adrenal function. The therapeutic efficacy of both regimens was equal. The advantages of alternate-day corticosteroid therapy are presented and the optimal way of starting this therapy discussed.


Influence of a uvrD mutation on survival and repair of X-irradiated Escherichia coli K-12 cells. The presence of a uvrD mutation increased the X-ray sensitivities of E. coli wild-type and polA strains, but had no effect on the sensitivities of recA and recB strains, and little effect on a lexA strain. Incubation of irradiated cells in medium containing 2,4-dinitrophenol or chloramphenicol decreased the survival of wild-type and uvrD cells, but had no effect on the survival of recA, recB and lexA strains. Alkaline sucrose gradient sedimentation studies indicated that the uvrD strain is deficient in the growth-medium-dependent (Type III) repair of DNA single-strand breaks. These results indicate that the uvrD mutation inhibits certain rec+lex+-dependent repair processes, including the growth-medium-dependent (Type III) repair of X-ray-induced DNA single-strand breaks, but does not inhibit other rec+lex+-dependent processes that are sensitive to 2,4-dinitrophenol and chloramphenicol.


Some mechanisms involved in the radiosensitization of E. coli B/r by paracetamol. Paracetamol, a widely-used analgestic and antipyretic drug, sensitized E. coli B/r to 60Co gamma-rays under hypoxic conditions. Part of the sensitizing effect has been shown to be due to an electron adduct of the drug. Paracetamol inhibited both post-irradiation DNA and protein syntheses. The targets involved in the inhibition of post-irradiation DNA synthesis have been shown to be different in the presence of the sensitizer. Increased DNA degradation after irradiation was also observed when E. coli B/r were irradiated in the presence of the drug. The presence of paracetamol during hypoxic irradiation of E. coli B/r resulted in the enhancement of DNA single-strand scissions with no apparent effect on their rejoining.


Split-dose and liquid-holding recovery after X-irradiation in diploid yeast Saccharomyces cerevisiae. II. Dependence of the recovery process on cellular protein metabolism. In diploid yeast, split-dose recovery (SDR) after X-irradiation was affected, if incubation between split doses was performed in the presence of the protein-synthesis inhibitor, cycloheximide. In exponentially-growing cell-cultures, early SDR was undisturbed but complete recovery was not achieved. Concomitantly the cells show a decresing ability to perform subsequent liquid-holding recovery (LHR). In stationary-phase cell-cultures, SDR was completely suppressed. The cells show, however, recovery from potentially lethal damage in the presence of cycloheximide during incubation between the dose-fractions. The experimental results suggest that in diploid yeast SDR after X-irradiation is an enzymatic process dependent on a functioning protein metabolism.


Specific detection of mycobacteria by the immunofluorescent technique. Using an indirect immunofluorescent technique, M. bovis var. BCG can be differentiated from M. avium in pure culture. The test involves using an unlabeled antiserum prepared against B-24, a type specific antigen of M. bovis var. BCG. In the same system M. bovis could be differentiated from other pathogenic my cobacteria in tissue sections of naturally and experimentally infected animals.


Ultrasonic diagnosis of renal and retroperitoneal lesions. The unique ability of ultrasound to detect soft tissue interfaces makes it a prime tool for at least one major diagnostic approach to soft tissue lesions. Systematic ultrasonic examination of suspected masses in the abdomen should be performed early in the course of investigation. It will help direct additional studies and often result in cost savings by making the diagnostic process more efficient. The method is painless, to the best of our knowledge harmless and can be repeated at will for early study or late follow-up. The ultrasonic look into the body has provided us with a major tool for obtaining far more information on internal structures than was possible even a few years ago. Ultrasonic scans, radioisotope examinations and computerized x-ray tomography are leading us into an era of much increased anatomic knowledge about lesions which heretofore were obscure and difficult to evaluate.


Aortosonography.

Aortosonography. Ultrasound should be considered as the primary procedure of choice in the evaluation of the abdominal aorta. It is noninvasive and does not require injection of contrast material. Both normal and abnormal ultrasonic aortic patterns are usually so typical that independent confirmation is not needed unless surgery is anticipated. In emergency situations involving rupture or dissection, the detection of an aneurysm by ultrasound often dramatically shortens the time interval between the emergency admission and actual surgery. The established uses for aortosonography are as follows: 1. Detection of a normal aorta. 2. Demonstration of an aneurysm (diffuse or localized). 3. Determination of its size, including both internal and external diameters. 4. Evaluation of internal echo patterns (clot or dissection). 5. Detection of lumen narrowing or occlusion. 6. Determination of aneurysm extension into the iliacs or thoracic aorta. 7. Evaluation of the major branches of the aorta. 8. Demonstration of other vessels such as the vena cava and portal vein as well as their branches. 9. Detection and differentiation of masses misdiagnosed as aneurysms. 10. Serial evaluation of aneurysms not having surgery to detect any change in size or internal pattern.


Echocardiography in congenital heart disease. An aid to surgical diagnosis. Echocardiography is an important noninvasive method for accurately diagnosing many congenital cardiac defects. This method provides significant information so that cardiac surgery, when necessary, can be planned with greater facility. The value of the sonar method rests not only on its ability to diagnose specific cardiac defects but also to exclude heart disease, especially in infants with shock or cyanosis from noncardiac causes. Development of two-dimensional real-time scanning systems should provide greater understanding of anatomic spatial relationships and ease of diagnosis.


In vitro specular microscope perfusion of M-K- and moist chamber-stored human corneas. Human donor corneas were stored in McCarey-Kaufman (M-K) medium for 3 to 6 days; then they were mounted in the specular microscope, and the endothelial surface perfused with a glutathione-bicarbonate-Ringer solution. During storage, the corneal thickness increased 37% above an assumed normal of 0.520 mm. The corneas did not have sufficient active thinning to be accepted as viable when tested by the temperature-reversal phenomenon. Since comparable donor corneas have been used in successful penetrating keratoplasties, there must be a discrepancy between the cell viability as tested by the temperature-reversal phenomenon and clinical application.


A comparison of antinuclear antibodies and DNA-binding antibodies in chronic open-angle glaucoma. Antinuclear antibodies (ANA) were examined in the sera of 28 patients with chronic open angle glaucoma (COAG) and 24 normal volunteers by an immunoperoxidase technique. Unlike the results of a previous report, no significant difference in titers was found between the two groups. A highly objective radioimmunoassay for DNA antibody was also employed, giving similar results. The increased incidence of ANA at low dilutions in both COAG and normal groups in this study and its absence when measured by radioimmunoassay suggest that positive ANA reactions at such low dilutions are the result of nonspecific binding. The lack of demonstrable differences from normal in ANA- or DNA-binding antibody does not support the results of earlier studies suggesting a humoral immune or autoimmune mechanism in COAG.


Rapid detection of specific treponemal antibodies by counterimmunoelectrophoresis using an extract of Treponema pallidum. Specific treponemal antibodies were detected in small amounts by counterimmunoelectrophoresis (CIE) in agar gel, using an extract of Treponema pallidum. The T. pallidum-CIE test was compared with the fluorescent treponemal antibody-absorption (FTA-ABS) test and with the Reiter protein complement fixation (RPCF) test. The results of the T. pallidum-CIE and FTA-ABS tests agreed in 96% of cases. There was no agreement between the T. pallidum-CIE and RPCF tests in 14% of cases. The three tests were compared in 56 sera--17 from cases of untreated syphilis and 39 from biologically false positive (BFP) reactors. RPCF was positive in 10 (59%) of the 17 specimens from cases of untreated syphilis; all 17 sera were FTA-ABS positive. The T. pallidum-CIE test was positive in 14 (82%) of the 17 specimens. All of the 39 BFP reactors, positive by the RPCF test, were shown to be negative by the FTA-ABS and T. pallidum-CIE tests. These results suggest that the T. pallidum-CIE test is more specific than the RPCF test and slightly less specific than the FTA-ABS test. The advantages of the T. pallidum-CIE test as a convenient method are speed of performance, simplicity and economy.


Studies on the immune response to fixed antigens. II. Optimal conditions for inducing and eliciting helper function by fixed antigens and the mechanism responsible for this effect. Heavily trinitrophenylated sheep red blood cells (RBC) (TNP128SRBC) and glutaraldehyde-treated SRBC (G-SRBC) induced helper function. This helper function could accelerate anti-SRBC and anti-TNP secondary responses to subsequent challenge with TNP0.14SRBC in different strains of mouse. Preferential induction of helper function over primary antibody response was obtained with fixed antigens only. High doses of fixed RBC (4 X 10(7) or 4 x 10(8)/mouse) could induce optimal helper function and high doses of the challenger TNP0.14SRBC (4 X 10(7) or 4 x 10(8)/mouse) could optimally recall this function and stimulate secondary responses. G-SRBC was a better inducer of helper function than low doses of nonmodified SRBC. TNP128SRBC-primed mice produced a significant anti-SRBC response after subsequent challenge with TNP0.14 mouse RBC. Reverse help was suggested as one of the possible mechanisms of this response. Early helper function which developed four days after priming with TNP128SRBC or G-SRBC could be transferred to irradiated recipients with T, but not B, cells. Late immunologic memory which appeared 18 days after priming with TNP128SRBC could be transferred to irradiated recipients only with a mixture of T and B cells.


Computer study of thyroid diseases. III. Statistical models. A binary-variable multiple-regression model is proposed for the computer diagnosis of thyroid disease. The procedure employs a multiple-regression technique in which each variable is assigned a value of either unity or zero. Unlike other current approaches, the proposed model uses only information about the patients themselves; no prior knowledge of the incidence of the disease in the population under study is required. The model was applied to data on 906 patients with suspected thyroid disorders referred to endocrine clinics in Israel. On the basis of simple physical findings and clinical signs and symptoms, the correct diagnosis was obtained in 95% of the cases for males and in 85% for females.


[Cryomacroglobulinemic purpura with liver cirrhosis and hepatic porphyria]. Hepatic porphoria and histologically verified cirrhosis, teleangiectasia, purpose, papular skin lesions existing for eight years, as well as cryomacroglobulin were found in a 49 year old man. Pathogenetically the liver disease is considered to be the primary event, which was accompanied by secondary cryoglobulinemia. IgG and IgM type of thrombus in the vessels and of small granular deposits corresponding to the type of cryoprotein in the blood, were detected in the vessel walls of the upper part in the dermis and along these vessels of both purpuri and papular skin lesions. Immunoprecipitates could be revealed by FTC-labelled antihuman complement. In the skin lesions porphyrin could not be demonstrated. The investigation of cryoglobulin and of porphyrin disorders is reasonable in every patient with purpura accompanying pathological liver processes.


Ribosome maturation in E. coli.

Ribosome maturation in E. coli. In vivo and in vitro experiments have shown that processing of ribosomal RNA is a late event in ribosome biogenesis. The precursor form of RNA is probably necessary to speed up the assembly of ribomal proteins. Newly formed ribosomal particles which have already entered polyribosomes differ from mature ribosomes not only in their RNA content but also in their susceptibility to unfolding in low Mg concentration and to RNase attack. Final maturation of new ribosomes is probably dependent on their functioning in protein synthesis. Thus only those ribosomes which have proven to be functional may be converted into stable cellular structures.


Communicating cancer control to the public. A fifty-year historical review of public communications research, an analysis of factors influencing communication effectiveness, descriptions of fifteen cancer public communication programs, and recommendations for future cancer communications programs are presented. The programs described were specific to five cancer sites, were targeted to six types of audiences and included several types of educational objectives and communication modes. Recommendations include greater use of social science literature and evaluative designs in program planning; cooperative research to provide data suitable for educational diagnosis; and standardization of evaluation results to document effectiveness of techniques and strategies.


Bactericidal studies of penicillin-gentamicin combinations against group B streptococci. The bactericidal activity of penicillin-aminoglycoside combinations was studied in 16 strains of Group B streptococci. Minimal inhibitory concentrations (MIC) against kanamycin or gentamicin were greater than 50 microgram/ml, whereas ampicillin or penicillin inhibitory concentrations were uniformly less than 0.1 microgram/ml. Although all strains had bactericidal concentrations (MBC) less than 0.1 microgram penicillin/ml, penicillin at a concentration equal to each strains respective MBC reduced inoculum colony forming units (CFU) 2 logs in only 6 of 16 strains in bactericidal kinetic studies. However, the addition of gentamicin in concentrations of 5.0 or 10.0 microgram/ml to penicillin markedly enhanced bactericidal activity in all strains tested. The addition of lower concentrations of gentamicin (1.0 microgram/ml) had minimal advantage over penicillin alone. No distinct advantage was noted for combinations including either ampicillin or kanamycin. The theoretical advantage of penicillin-aminoglycoside combinations in experimental conditions, suggests that the use of antibiotic combinations in clinical infections due to Group B streptococci, may result in a more rapid eradication of these organisms.


Total body water and lean body mass estimated by ethanol dilution. Total body water (TBW) was determined on 35 subjects with a tritium (HTO) and an ethanol (ETH) dilution method, the latter using breath analyses for blood ethanol content. Lean body mass (LBM) was estimated by hydrostatic weighing. Mean values for water fraction (TBW/wt) were 0.618 +/- 0.05 with HTO and 0.603 +/- 0.06 with ETH. The difference was not significant. The correlation between the two methods was highly significant (r = 0.90, SEE = 3.5 liters, P less than 0.0001). High correlations were also found between TBW and LBM with either method for TBW (r = 0.94 with HTO, r = 0.91 with ETH). Mean values for TBW/LBM were 0.735 with HTO and 0.717 with ETH. The ETH method compares favorably with the HTO, it has the advantage that it is nonradioactive and can be repeated daily if necessary.


Mutations of temperature sensitivity in R plasmid pSC101. Temperature-sensitive (Ts) mutant plasmids isolated from tetracycline resistance R plasmid pSC101 were investigated for their segregation kinetics and deoxyribonucleic acid (DNA) replication. The results fit well with the hypothesis that multiple copies of a plasmid are distributed to daughter cells in a random fashion and are thus diluted out when a new round of plasmid DNA replication is blocked. When cells harboring type I mutant plasmids were grown at 43 degrees C in the absence of tetracycline, antibiotic-sensitive cells were segregated after a certain lag time. This lag most likely corresponds to a dilution of plasmids existing prior to the temperature shift. The synthesis of plasmid DNA in cells harboring type I mutant plasmids was almost completely blocked at 43 degrees C. It seems that these plasmids have mutations in the gene(s) necessary for plasmid DNA replication. Cells haboring a type II mutant plasmid exhibited neither segregation due to antibiotic sensitivity nor inhibition of plasmid DNA replication throughout cultivation at high temperature. It is likely that the type II mutant plasmid has a temperature-sensitive mutation in the tetracycline resistance gene. Antibiotic-sensitive cells haboring type III mutant plasmids appeared at high frequency after a certain lag time, and the plasmid DNA synthesis was partially suppressed at the nonpermissive temperature. They exhibited also a pleiotrophic phenotype, such as an increase of drug resistance level at 30 degrees C and a decrease in the number of plasmid genomes in a cell.


Further characterization of the F fertility inhibition systems of "unusual" Fin+ plasmids. Flac mutants insensitive to transfer inhibition by R factors. JR66a and R485 were isolated and characterized. Representative mutations were cis dominant and are therefore presumed to be at the sites of action, fisU and fisV, respectively, of the FinU and FinV transfer inhibition systems encoded by JR66a and R485. The mutants were used to confirm that the FinU and FinV fertility inhibition systems are different from each other and from the FinOP, FinQ, and FinW systems of R100, R62, and R455, respectively. Together with traO and fisQ mutants of Flac, the new mutants were also used to investigate the nature of the F fertility inhibition systems encoded by a further group of "unusual" Fin+ plasmids. Of these, two incompatibility group X plasmids were found to carry finO+ genes, and of five incompatibility group I plasmids, three encoded FinQ systems, one the FinU system, and one a new system (FinR). Transfer of a variety of derepressed F-like plasmids was inhibited by the FinQ, FinU, and FinV systems, but a quantitatively very different levels; this emphasizes the differences as well as the similarities between the conjugation systems of F-like plasmids.


Suppression of an Escherichia coli dnaA mutation by the integrated R factor R100.1: origin of chromosome replication during exponential growth. We have investigated the behavior, during exponential growth, of strains of Escherichia coli carrying a dnaA(Ts) mutation that has been suppressed by the integration of the F-like R plasmid R100.1. We present evidence showing that replication in these strains proceeds largely from the normal chromosome origin at 30 degrees C, a permissive temperature for the dnaA(Ts) gene product, whereas, at 42 degrees C, replication proceeds largely from the integrated plasmid. These conclusions are based on measurements made by deoxyribonucleic acid:deoxyribonucleic acid hybridization of the relative frequencies of the prophages Mu-1 and lambdaind- and R100.1 integrated at known locations on the E. coli chromosome in these Hfr strains.


Induction of alkaline phosphatase in Escherichia coli: effect of procaine hydrochloride. The effect of procaine hydrochloride, an anesthetic known to alter membrane structure, on the induced formation of alkaline phosphatase, a periplasmic enzyme, in Escherichia coli was investigated. Procaine hydrochloride specifically arrested the appearance of active alkaline phosphatase while permitting the induction of another enzyme, beta-galactosidase, which is internally localized. Evidence has been obtained to show that procaine hydrochloride does not arrest synthesis of inactive monomer subunits of the enzyme, indicating that the drug interferes in the conversion of monomer subunits to an active dimer enzyme.


Chromosome structure of Escherichia coli mutants temperature sensitive for deoxyribonucleic acid replication. Folded chromosomes were isolated from Eschericia coli thermosensitive dnaA initiation mutants incubated at the nonpermissive temperature and were analyzed by neutral sucrose density gradient centrifugation. A chromosomal structure that sedimented at approximately 1,500S accumulated when the dnaA gene product was inactive. When the cells were returned to a permissive temperature, the folded chromosomes exhibited a decrease in sedimentation velocity to 1,300S but still retained their uniform structure. Very little deoxyribonucleic acid synthesis occurred during the period in which the chromosomes exhibited the reduction in sedimentation velocity. A dnaG elongation mutant showed no unique chromosome structure when the dnaG gene product was inactive.


Two systems for the uptake of phosphate in Escherichia coli. Mutants of Escherichia coli K-12 were constructed such that each possessed one single major system for phosphate transport. A comparison of these strains showed that one of the systems (PIT) was fully constitutive, required no binding protein, and operated in spheroplasts. It permitted the complete exchange of intracellular phosphate with extracellular phosphate (or arsenate) and was completely inhibited by uncouplers. The other system, PST, was repressible by phosphate concentrations above 1 mM, required the phosphate-binding protein for full activity, and did not operate in spheroplasts. It catalyzed very little exchange between internal and external phosphate and was resistant to uncouplers. The maximal velocities attained by the two systems were approximately the same, but the affinity for phosphate in the PST system was greater by two orders of magnitude. In strains in which both systems were fully operative, the initial rates of uptake was nearly additive, and the systems appeared to interact with a common intracellular phosphate pool.


Restoration of phosphate transport by the phosphate-binding protein in spheroplasts of Escherichia coli. Reconstitution of phosphate transport in Escherichia coli was demonstrated. Conversion of E. coli K10 cells to spheroplasts decreased phosphate transport to about 2%. Addition of purified phosphate-binding protein at physiological levels to these spheroplasts caused a mean 14-fold increase in phosphate transport rate. Crude shock fluid fractions were also stimulatory but not if the shock fluid was obtained from mutants lacking phosphate-binding protein. The effect of the binding protein was abolished by its specific antibody. The phosphate was shown to have entered the cell, where it became esterified. Reconstitution was not possible with cold-shocked or osmotically shocked cells.


Characterization of lexB mutations in Escherichia coli K-12. Two mutations have been located at the recA locus and phenotypically characterized along with a third one, previously called rec-34. The three mutants behaved similarly to lexA mutants. They were sensitive to ultraviolet (UV) light and X rays, and lambdaFec- phages were able to plate on them. The three mutations were called lexB because they could be distinguished from recA mutations by the last property. lexB mutants were less sensitive to UV and X irradiations than were recA mutants and were, to various degrees, recombination proficient. UV light failed to induce prophage lambda in all three lexB lysogens. In contrast, thymine starvation induced lexB31 and lexB34 lysogens. In lexB34 mutants, but not in lexB30 and lexB31 mutants, UV reactivation occurred at a low level. In Escherichia coli K-12, the recA gene has basic functions in the repair of deoxyribonucleic acid lesions, deoxyribonucleic acid recombination, and prophage induction. The three lexB mutations alter unequally and independently the three functions. This suggests that the recA and lexB mutations affect the same gene.


Two modes of metabolic regulation of lysyl-transfer ribonucleic acid synthetase in Escherichia coli K-12. Lysyl-transfer ribonucleic acid (tRNA) synthetase activity was compared in three independently isolated Escherichia coli K-12 mutants of the enzyme S-adenosyl-L-methionine synthetase (metK mutants) and their isogenic parents. In all three cases the activity of the lysyl-tRNA synthetase was elevated two- to fourfold in the mutant strains. Glycyl-L-leucine (3 mM) usually enhanced lysyl-tRNA synthetase activity two- to threefold in wild-type cells but did not further stimulate the synthetase activity in metK mutants. By two other criteria, the lysyl-tRNA synthetase from wild-type cells grown with the peptide and from the metK mutant RG62, grown in minimal medium, were similar. These criteria are enhanced resistance to thermal inactivation and altered susceptibility to endogenous proteases when compared with the synthetase from wild-type cells grown in minimal medium. In a separate set of experiments, the activities of the lysyl-, arginyl-, seryl-, and valyl-tRNA synthetases were measured in an isogenic pair of relt and rel strains of E. coli grown in a relatively poor growth medium (acetate) and in enriched medium. In the rel+ strain the level of all four synthetases was higher (two- to fourfold) in the enriched medium as expected. In the rel strain the difference in the activities of the synthetases between the two media were diminished. In all four cases the activities of the synthetases were higher in acetate medium in the rel strain. Evidence is presented that these two modes of metabolic regulation act independently.


Outer membrane proteins of Escherichia coli. V. Evidence that protein 1 and bacteriophage-directed protein 2 are different polypeptides. Protein 1 from the outer membrane of Escherichia coli K-12 and protein 2 from a phage PA-2 lysogen of the same strain were isolated by differential sodium dodecyl sulfate extraction and purified by ion-exchange and gel filtration chromatography. Rabbit antisera were prepared against these proteins and showed no cross-reaction between proteins 1 and 2. The proteins have the same N-terminal amino acid but show small yet significant differences in amino acid composition. The proteins were cleaved with cyanogenbromide in solvents containing both formic acid and trifluoroacetic acid. By comparing the cleavage in these solvents, it was established that protein 1 yielded 5 cyanogen bromide peptides, and the sum of the molecular weights of these was equivalent to the molecular weight of the uncleaved protein. Protein 2 yielded 4 cyanogen bromide peptides, none of which was identical to those of protein 1, and the sum of these peptides was also equivalent to the apparent molecular weight of the uncleaved protein. Significant differences were also observed when tryptic peptides from the two proteins were compared. These results indicate that protein 1 and the phage-directed protein 2 are distinct, different, and apparently homogeneous proteins.


Outer membrane proteins of Escherichia coli. VI. Protein alteration in bacteriophage-resistant mutants. Protein 1 was shown to be the receptor for phage PA-2 by the observations that the purified protein inactivates the phage, mutants lacking the protein are resistant to the phage, and mutants selected for PA-2 resistance have altered protein. Protein 1 appears as two bands (1a and 1b) on high-resolution polyacrylamide gels. The most abundant classes of mutants (ParI and ParII) selected for PA-2 resistance were found to lack band 1b. The mutations responsible for the ParI and ParII phenotypes were mapped at a locus termed par, which is near nalA on the Escherichia coli chromosome. The cyanogen bromide peptides of proteins 1a and 1b are similar, suggesting that these bands represent modified forms of the same polypeptide. Strains carrying the tolF mutation produce only band 1b. When a par tolF double mutant was constructed, this strain produced only band 1a. These results suggest that genes at the par and tolF loci are involved in modification of protein 1, or regulation of such modification, and are not structural genes for protein 1.


Influence of osmolarity of the growth medium on the outer membrane protein pattern of Escherichia coli. Supplementation of the growth medium with high concentrations of NaCl, KCl, or sucrose caused a drastic change in the ratio of the two peptidoglycan-associated major outer membrane proteins of Escherichia coli K-12 in that the amounts of proteins b and c present in cell envelope preparations decreased and increased, respectively. Kinetic studies showed that, after the osmolarity of the medium was changed, one protein was hardly incorporated into the membrane, whereas the other was incorporated with an increased rate. After about 1.5 to 2 generations, the cell envelopes obtained the b/c ratio characteristic for the new medium, and both proteins were subsequently incorporated in the cell ensured this new ratio. Once proteins b and c were incorporated in the cell envelope, they were not converted into each other by changes in osmolarity of the growth medium.


Role of a major outer membrane protein in Escherichia coli. Mutants of Escherichia coli B/r lacking a major outer membrane protein, protein b, were obtained by selecting for resistance to copper. These mutants showed a decreased ability to utilize a variety of metabolites when the metabolites were present at low concentrations. Also, mutants of E. coli K-12 lacking proteins b and c from the outer membrane were shown to have an identical defect in the uptake of various metabolites. These results are discussed with regard to their implications as to the role of these proteins in permeability of the outer membrane,


Localization of acid phosphatase in Saccharomyces cerevisiae: a clue to cell wall formation. Acid phosphatase is present in two layers of the cell envelope of Saccharomyces cerevisiae. These are separated by another layer, which is free of acid phosphatase. We have evidence that the cell wall is built up in two stages, which are independent. In the first stage, the cell wall is built up during the formation of the bud. Glucanase vesicles are involved in this process. In the second stage, a thick layer is deposited at the inside against the new cell wall. This results in the thick, rigid wall of the mature yeast cell. This latter layer is probably assembled on the outer surface of the plasmalemma.


Secondary promoter of the guanine operon of Escherichia coli K-12. Evidence of a secondary promoter for the guaA gene within the guaB gene was obtained by using lambdapguaA transducing phage. The technique is generally applicable to distinguish a promoter present within a bacterial deoxyribonucleic acid segment, which has replaced the lambda b2 region of transducing phage, from the phage pI promoter.


Influence of rec and pol genes on the maintenance of a Proteus plasmid (P-lac) in Escherichia coli. The maintenance requirements of a Proteus plasmid, P-lac, in Escherichia coli have been investigated. P-lac could not be inherited by recB and polA1 mutants, and it requires a functional recC gene for maintenance. P-lac replication was inhibited by chloramphenicol.


Phosphoenolpyruvate:sugar phosphotransferase system in Ancalomicrobium adetum. Ancalomicrobium adetum possesses a membrane-associated phosphoenolpyruvate:sugar phosphotransferase system, the components of which exhibited enzymatic cross-reactivity with those from Salmonella typhimurium.


Effects of detergents on the conformation of Escherichia coli tRNA as measured by circular dichroism. The effect of a cationic detergent, lauryl pyridiniumchloride (LPC), and an anionic one, sodium n-octylbenzenesulfonate (SOBS), on the conformation of unfractionated Escherichia coli tRNA was investigated at various molar ratios of detergent to tRNA (D/R) in the presence and absence of Mg2+ and Na+ ions by measuring the circular dichroism (CD) at 265 nm and 340 nm, which reflects conformational change involving base pairs and/or base stacking, and the disymmetry in the vicinity of 4-thiouridylate (4-TU), respectively. In the presence of Mg2+ and Na+ ions, the tRNA retains its native structure even in the presence of high molar ratios of detergent to tRNA (D/R congruent to 40 at 265 nm and D/R congruent to 20 at 340 nm). However, in the absence of these metal ions, the ellipticity at 340 nm was very sensitive to LPC concentration and decreased from 5,600 to nearly--1,600 at 25 degrees C with the increase of D/R ratios up to 20, and a similar decrease in the ellipticity at 340 nm was observed on thermal denaturation. This result suggests that the local environment involving the 4-TU region might be readily influenced by LPC, reflecting a large conformational change. However, no effect was observed in the case of the SOBS: tRNA system. On the other hand, secondary base pairing and/or base stacking structure was virtually invariant on adding both LPC and SOBS even at high D/R ratios in the absence of Mg2+ and Na+ ions.


Fluorescent probes for antibody active sites. II. Further studies on two groups of anti-MANS antibodies with significantly different effects on MANSamide fluorescence produced by a single rabbit. As described previously, a single rabbit (No. 13) produced two groups of anti-MANS antibodies with significantly different effects on MANSamide fluorescence. These groups, anti-MANS antibody (415 nm) and anti-MANS antibody (465 nm), had emission maxima at 415 nm and 465 nm, respectively. This paper deals with the immunochemical properties of the two groups of antibodies (1) The results of fluorometric titration of these groups with MANSamide indicated that anti-MANS antibody (465 nm) had a higher affinity for MANSamide than did anti-MANS antibody (415 nm). (2) More than 70% of anti-MANS antibody (415 nm) was adsorbed on Sepharose covalently coupled with bovine serum albumin, which was used as a carrier during immunization, while a hlaf of anti-MANS antibody (465 nm) was adsorbed. (3) Only one of the groups, anti-MANS antibody (465 nm), had precipitating activity toward MANS-rabbit serum albumin used as a test antigen.


Escherichia coli ribosomal protein S1 recognizes two sites in bacteriophage Qbeta RNA. As a component of bacteriophage Qbeta replicase, S1 is required both for initiation of Qbeta minus strand RNA synthesis and for translational repression, which has been traced to the ability of the enzyme to bind to an internal site in the Qbeta RNA molecule. Previously, Senear and Steitz (Senear, A. W., and Steitz, J. A. (1976) J. Biol. Chem. 251, 1902-1912) found that isolated S1 protein binds specifically to an oligonucleotide spanning residues -38 to -63 from the 3' terminus of Qbeta RNA. Here we report that S1 also interacts strongly with a second oligonucleotide in Qbeta RNA, which is derived from the region recognized by replicase just 5' to the Qbeta coat protein cistron. Both sequences exhibit pyrimidine-rich regions.


Threonine-sensitive homoserine dehydrogenase and aspartokinase activities of Escherichia coli K12. Kinetic and spectroscopic effects upon binding of serine and threonine. The two threonine-sensitive activities aspartokinase and homoserine dehydrogenase are inhibited by L-serine. The inhibition of the aspartokinase by L-serine displays homotropic cooperative effects and is competitive versus aspartate. The inhibition by L-serine of the homoserine dehydrogenase displays Michaelis-Menten kinetics which are of a competitive nature versus homoserine. Characteristic effects of L-serine on the protein include a perturbation of its absorption and fluorescence spectra, with an increase in the fluorescence of the protein-NADPH complex. L-serine shifts the allosteric equilibrium of the protein to a "T-like" conformation to which L-threonine binds noncooperatively. L-Serine, a threonine analog, is not capable, as the physiological effector, of inducing a complete R to T transition of the enzyme; the aspartokinase globules show a cooperative conformation change upon serine binding, but this conformation change is not found in the homoserine dehydrogenase globules.


Binding of Escherichia coli RNA polymerase to T7 DNA. Displacement of holoenzyme from promoter complexes by heparin. Escherichia coli RNA polymerase holoenzyme bound to promoter sites on T7 DNA is attacked and inactivated by the polyanion heparin. The highly stable RNA polymerase-T7 DNA complex formed at the major T7 A1 promoter can be completely inactivated by treatment with heparin, as shown by monitoring the loss of activity of such complexes, and by gel electrophoresis of the RNA products transcribed. The rate of this inactivation is much faster than the rate of dissociation of RNA polymerase from promoter complexes, and thus represents a direct attack of heparin on the polymerase molecule bound at promoter A1. Experiments employing the nitrocellulose filter binding technique suggest that heparin inactivates E. coli RNA polymerase when bound to T7 DNA by directly displacing the enzyme from the DNA. RNA polymerase bound at a minor T7 promoter (promoter C) is much less sensitive to heparin attack than enzyme bound at promoter A1. Thus, the rate of inactivation of RNA polymerase-T7 DNA complexes by heparin is dependent upon the structure of the promoter involved even though the inhibitor binds to a site on the enzyme molecule.


Mechanism of the apparent regulation of Escherichia coli unsaturated fatty acid synthesis by exogenous oleic acid. Starvation of strains of Escherichia coli which are glycerol auxotrophs and are also defective in beta oxidation results in the accumulation of large amounts of free fatty acid (Cronan, J. E., Jr., Weisberg, L. W., and Allen, R. G. (1975) J. Biol. Chem. 250, 5835-5840). We now report that addition of exogenous oleic acid to these cultures results in no decrease in the synthesis of the unsaturated acids of the free fatty acid fraction although a 40 to 60% decrease of [14C]acetate incorporation into phospholipid unsaturated acyl moieties occurs under these conditions. This result indicates that the decreased synthesis of phospholipid unsaturated acyl moieties observed by others during oleic acid supplementation can be attributed to competition between exogenous and endogenously synthesized unsaturated fatty acids rather than a curtailment of unsaturated fatty acid synthesis per se.


Purification and some properties of Escherichia coli tRNA nucleotidyltransferase. Adenylyl (cytidylyl)-tRNA nucleotidyltransferase (ATP (CTP): tRNA adenylyl (cytidylyl)transferase, EC2.7.7.25) has been purified 11,800-fold from a crude extract of Escherichia coli B in an overall yield of 23%. The key step in this purification is the use of a tRNA-Sepharose affinity column. The purified enzyme has a specific activity of approximately 280 mumol of AMP incorporated/min/mg of protein at 37 degrees and has a molecular weight of 52,000 as determined by sodium dodecyl sulfate gel electrophoresis of Sephadex chromatography. The turnover number of the pure enzyme, under optimal assay conditions, is estimated as 21,000, and we believe it constitutes only o.oo6% of the total cellular protein. Both AMP- and CMP-incorporating activities have an identical isoelectric point of 5.85. The AMP-incorporating activity of the enzyme is inhibitied by some transition metal chelating agents but not by others.


Synthesis of RNA from cellulose-bound complementary DNA. Radioactively labeled RNAs were synthesized from cellulose-bound cDNA templates using Escherichia coli RNA polymerase. Hybridization of this RNA to excess unlabeled cDNA approached 100%, indicating the complementarity of product and template. The average length of the RNA product, as determined by formamide gels, was approximately 40% of the template length. Hybridization of unlabeled globin RNA produced by this technique to labeled globin cDNA indicated the population of RNA sequences represented at least 80% of the template sequences. Approximately 30% of the RNA product by mass contains poly(A) tails as determined by binding to oligo(dT)-cellulose. The template can be reused for several cycles of synthesis with little loss of synthetic capability and therefore, can amplify the amount of mRNA initially used to produce the template.


Base-unpaired regions in supercoiled replicative form DNA of coliphage M13. Superhelical covalently closed circular replicative form DNA (RF I) of coliphage M13 appears as a relaxed molecule that has a base-unpaired region in the form of a bubble (100 to 200 base pairs long) seen in electron micrographs when spread in the presence of formaldehyde and formamide or after pretreatment with glyoxal. S1 endonuclease, specific for single-stranded DNA, converts superhelical M13 RF I DNA, but not nonsuperhelical M13 RF I to a significant extent, into unit-length linear molecules by sequential nicking of two strands. The locations of S1 nuclease-susceptible sites and glyoxal-fixed base-unpaired regions were both related to the five A-T-rich regions in M13 RF DNA. While S1 nuclease does not show preference for any of these sites, glyoxal-fixed bubbles occur predominantly at the major A-T-rich region in M13 RF DNA.


Possible use of the oxygen uptake rate in the evaluation of BCG vaccines. Two existing methods suitable for the determination of the oxygen uptake rate (OUR) in BCG suspensions (Warburg and Gilson Oxygraph) are described and compared. With the former method the oxygen uptake rates of the 10 samples of the BCG collaborative assay of the BCG Steering Committee of the International Association of Biological Standardization were determined. When the results are compared with those of colony count and skin reactivity from the collaborative assay, there is a better correlation between OUR and skin reactivity than between OUR and colony count. From the results of our study there is a strong indication that the OUR is a good parameter for quality, and most probably better suited for interlaboratory comparisons than the colony count.


Evaluation of BCG vaccines in children, the effect of strain and dose. This paper presents results from a number of studies where different BCG products and BCG strains were compared and evaluated by the immediate effect after vaccination. It was shown that BCG strains differ in terms of allergenic potency. However, two products prepared from the same strain in different laboratories may differ more than two products prepared from different strains in one laboratory. Thus for products prepared from different strains in different laboratories the allergenic potency may differ as a result of differences between strains, production methods and concentrations. Any difference in allergenic potency observed between products from different laboratories, therefore, cannot give conclusive information on a single characteristic.


Report on results of a collaborative assay of BCG vaccines organized by the International Associaton of Biological Standardization. In a collaborative assay initiated by the International Association of Biological Standardization 13 laboratories investigated the properties of 10 freeze-dried BCG vaccines made in different ways by different producers which met the requirements of the World Health Organization. The in vitro tests with respect to the dry weight of the bacteria, the number of culturable particles and the stability during storage at 37 degrees C gave results which showed statistically significant differences between vaccines as well as between laboratories. The use of a reference vaccine in the tests for the number of culturable particles did not improve the precision of the results. These tests are useful as in-process tests to assure the producer that his vaccine will consist of the required amount of bacteria of which a high percentage is living. It was found that all vaccines had a survival of more than 25% after 1 month at 37 degrees C with the exception of two vaccines in rubber-stoppered vials. The two in vivo tests, determining skin reactivity in guinea-pigs and multiplication of BCG in spleens of mice, resulted in nearly the same ranking of the vaccines with respect to their virulence, differing from that of the in vitro tests. In the skin reactivity test the simultaneous injection of both the reference vaccine and a test vaccine into the same animal achieved the elimination of the inter-laboratory variation of the results.


Physiological regulation of total tubulin and polymerized tubulin in tissues. Polymerized and depolymerized forms of tubulin were measured in rat and mouse liver, rat islets, human lymphocytes, and platelets. The percent of the total tubulin present in the polymerized form varied from 30.3 +/- 1.5% in the liver of the fed rat to 89.2 +/- 0.2% in human platelets. Fasting decreased the total tubulin and to a greater extent the polymerized form of tubulin in both rat and mouse liver. Glucose feeding increased the polymerized tubulin without affecting the total tubulin content in rat liver. Phytohemagglutinin-stimulated lymphocytes exhibited at least a three-fold increase in total tubulin (expressed in terms of DNA content), which during the initial 48 h of incubation was accounted for in toto by an increase in polymerized tubulin. It is suggested that the lectin not only accelerates tubulin synthesis but also stimulated the polymerization process. Storage of platelets at 4 degrees C for 6 days resulted in a marked decrease in total tubulin and an even greater reduction in the polymerized form. It is concluded that both the total tubulin content and its degree of polymerization can be modulated independently by a wide variety of physiological factors.


Changes in the distribution of a major fibroblast protein, fibronectin, during mitosis and interphase. The distribution of a major fibroblast protein, fibronectin, was studied by immunofluorescence and immunoscanning electron microscopy in cultures of human and chicken fibroblasts during different phases of the cell cycle. The main findings were: (a) In interphase cells, the intensity of surface-associated fibronectin fluorescence correlated with that of intracellular fibronectin fluorescence. (b) The intensity of the fluorescence of both surface-associated and intracellular fibronectins was not changed in cells that were synthesizing DNA. (c) Mitotic cells had reduced amounts of surface-associated but not of intracellular fibronectin. The surface fibronectin that remained on meta-, ana-, or telophase cells had a distinct punctate distribution and was also localized to strands attaching the cells to the substratum. Fibronectin strands first reappeared on the surface of flattening cytoplasmic parts of telophase cells. (d) Fibronectin was also detected in extracellular fibrillar material on the growth substratum, particularly around dividing cells. Thus, surface-associated fibrillar fibronectin was present during G(1), S, and G(2) but in cells undergoing mitosis the distribution was altered and the amount appeared to be reduced. The observations on the distribution of surface-associated fibronectin suggest that rather than being involved in growth control this fibronectin plays a structural role in interactions of cells with the environment.


Studies on proinsulin and proglucagon biosynthesis and conversion at the subcellular level. I. Fractionation procedure and characterization of the subcellular fractions. Anglerfish islets were homogenized in 0.25 M sucrose and separated into seven separate subcellular fractions by differential and discontinuous density gradient centrifugation. The objective was to isolate microsomes and secretory granules in a highly purified state. The fractions were characterized by electron microscopy and chemical analyses. Each fraction was assayed for its content of protein, RNA, DNA, immunoreactive insulin (IRI), and immunoreactive glucagon (IRG). Ultrastructural examination showed that two of the seven subcellular fractions contain primarily mitochondria, and that two others consist almost exclusively of secretory granules. A fifth fraction contains rough and smooth microsomal vesicles. The remaining two fractions are the cell supernate and the nuclei and cell debris. The content of DNA and RNA in all fractions is consistent with the observed ultrastructure. More than 82 percent of the total cellular IRI and 89(percent) of the total cellular IRG are found in the fractions of secretory granules. The combined fractions of secretory granules and microsomes consistently yield >93 percent of the total IRG. These results indicate that the fractionation procedure employed yields fractions of microsomes and secretory granules that contain nearly all the immunoassayable insulin and glucagons found in whole islet tissue. These fractions are thus considered suitable for study of proinsulin and proglucagon biosynthesis and their metabolic conversion at the subcellular level.


Time dependent modifications in arterial flow in a transplanted pulmonary lobe. Study of pulmonary arterial flow in the transplanted lung by means of an implanted ultrasonic flowmeter enables us: 1. To confirm results obtained by other methods (De Bono,8 Strider14 and Strandberg18): without specific treatment, rejection of graft causes increased peripheral resistances and the pulmonary arterial flow decreases progressively. 2. To prove by direct observation the existence in the treated animal of authentic precapillary shunts whose importance can cause the animal's death through functional disorder alone.


Studies on proinsulin and problucagon biosynthesis and conversion at the subcellular level. II. Distribution of radioactive peptide hormones and hormone precursors in subcellular fractions after pulse and pulse-chase incubation of islet tissue. Anglerfish proinsulin and insulin were selectively labeled with [(14)C]isoleucine, while proglucagon, conversion intermediate(s), and glucagon were selectively labeled with[(3)H]tryptophan. After various periods of continuous or pulse-chase incubation, islet tissue was subjected to subcellular fractionation. Fraction extracts were analyzed by gel filtration for their content of precursor, conversion intermediate(s), and product peptides. Of the seven subcellular fractions prepared after each incubation, only the microsome and secretory granule fractions yielded significant amounts of labeled insulin-related and glucagon-related peptides. After short-pulse incubations, levels of both [(14)C]proinsulin and [(3)H]proglucagon (mol wt approximately 12,000) were highest in the microsome fraction. This fraction is therefore identified as the site of synthesis. With increasing duration of continuous incubation or during chase incubation in the absence of isotopes, proinsulin, proglucagon, and conversion intermediate(s) are transported to secretory granules. Conversion of proinsulin to insulin and proglucagon to a approximately 4,900 mol wt conversion intermediate and 3,500 mol wt glucagon occurs in the secretory granules. Converting activity also was observed in the microsome fraction. The recovery of most of the incorporated radioactivity in microsome and secretory granule fractions indicates that the newly synthesized islet peptides are relegated to a membrane-bound state soon after synthesis at the RER is completed. This finding supports the concept of intracisternal sequestration and intragranular maintenance of peptides synthesized for export from the cell of origin.


Quantitation of a transformation-sensitive, adhesive cell surface glycoprotein. Decrease of several untransformed permanent cell lines. We have quantitated the transformation-sensitive, cell surface LETS glycoprotein on many untransformed cell types. By SDS-polyacrylamide gel electrophoresis, this trypsin-sensitive iodinatable glycoprotein comprises 1-3% of total cellular protein of the seven early passage cell types tested. In contrast, it constitutes less than 0.15% of the protein in four of six continuous cell lines. This decrease is reflected in alterations both in [14C]glucosamine labeling and in the immunofluorescent staining of early passage vs. these four permanent cell lines. These results help to clarify previous experiments in which CSP, a purified LETS protein, partially restored a fibroblastic phenotype to cells transformed by tumor viruses. These findings also indicate that a major decrease in this cell surface glycoprotein can occur in the establishment of a continuous cell line without resulting in cellular transformation.


[Endométriosis of the small intestine. Report of 4 new cases of stenosis of the small intestine (author's transl)]. The authors report 4 new cases of stenosis of the small intestine of endometrial origin. They emphasize the rareness of these stenosing forms which in most recent series intervened in 1 case of endometriosis out of 1,000 (Martinbeau). They consider the various clinical presentations encountered, asymptomatic forms discovered by chance, forms associated with suggestive gynecological disorders, chronic stenosis of the small intestine or presentation with intestinal obstruction. They consider the diagnostic difficulty in the isolated forms (2 cases) in the absence of pelvi-genital lesions. Among the positive factors, they consider the recrudescence during theperiods of the digestive signs, the macroscopic appearance of the lesions and, above all, the mucosal integrity noted on opening the specimen after intestinal resection. Finally, they consider certain special problems, that of bi-polar intestinal involvement with double localisation, involving the ileum and the recto-sigmoid areas.


[Hemorrhage complications of acute pancreatitis (author's transl)]. The authors report 11 cases of hemorrhage due to vascular ulcerations arising early or late in the course of acute pancreatitis. The seriousness of these hemorrhages, the difficulties of their therapy are pointed out. In all cases, bleeding should be controlled by surgery. Therefore, attention is drawn to the need for prompt laparotomy in all the shocked patients who failed to respond to conservative measures, for in such cases, a fatal outcome may rapidly occur. The respective advantages and inconveniences of the 2 main surgical treatments, ligation of bleeding vessels or pancreatectomy removing the source of bleeding, are discussed, basing on the presently reported cases and the data of the literature.


[The removal of gastrin secreting tissue in the treatment of Zollinger-Ellison syndrome (author's transl)]. In the light of 24 cases, routine total gastrectomy in the treatment of Zollinger-Ellison's syndrome should be abandoned in favour of the removal of gastrin-secreting tissue. This treatment which gives just as good results on the ulcer disease, also has the advantage of removal of the tumour tissue malignant in almost 2/3 of cases. Removal of the gastrin secreting tissue thus becomes the operation of choice. Total gastrectomy remains a last resort operation if it proves impossible to find or remove the gastrinoma, or, if after removal of the original tumour, there occurs a relapse of the ulcers or spread of the neoplasm.


Rapid micro-method for the measurement of diazepam and desmethyldiazepam in blood plasma by gas-liquid chromatography. A rapid gas-liquid chromatographic technique has been developed for use in the simultaneous measurement of both diazepam and its major metabolite, desmethyldiazepam, in blood plasma. Neither solvent transfer nor evaporation steps are required in this procedure. Extremely small plasma volumes (20 to 100 microleter) are used and this has proved advantageous, especially when analysing samples from neonates. A linear response to amounts from 1-10(-12) to 1-10(-9) g/sec of both diazepam and desmethyldiazepam has been obtained and thus the direct analyses of these compounds both during therapy and after overdosage has been possible. Interference from either endogenous or exogenous sources has been found to be minimal.


Recovery of anaerobic, facultative, and aerobic bacteria from clinical specimens in three anaerobic transport systems. With aspirated specimens from clinical infections, we evaluated the recovery of anaerobic, aerobic, and facultative bacteria in three widely used transport systems: (i) aspirated fluid in a gassed-out tube (FGT), (ii) swab in modified Cary and Blair transport medium (SCB), and (iii) swab in a gassed-out tube (SGT). Transport tubes were held at 25 degrees C and semiquantitatively sampled at 0, 2, 24, and 48 h. Twenty-five clinical specimens yielded 75 anaerobic strains and 43 isolates of facultative and 3 of aerobic bacteria. Only one anaerobic isolate was not recovered in the first 24 h, and then, only in the SGT. At 48 h, 73 anaerobic strains (97%) were recovered in the FGT, 69 (92%) in the SCB, and 64 (85%) in the SGT. Two problems hindered the recovery of anaerobes in the SCB and SGT systems: first die-off of organisms, as evidenced by a decrease in colony-forming units of 20 strains (27%) in the SCB and 25 strains (33%) in the SGT, as compared with 7 strains (9%) in the FGT, over 48 h; and second, overgrowth of facultative bacteria, more frequent with SCB and SGT. The FGT method was clearly superior at 48 h to the SCB and SGT systems in this study and is recommended as the preferred method for transporting specimens for anaerobic culture.


Clinical trial with "R-75" strain live, attenuated, serum inhibitor-resistant intranasal influenza B vaccine. The "R-75" strain live, attenuated, serum inhibitor-resistant influenza B vaccine was administered intranasally by drops in two doses 14 days apart to 21 volunteers. Each vaccinee was paired with a close associate (roommate or workmate) who similarly received two doses of a placebo solution. Although about 50% of both vaccine and placebo recipients complained of symptoms after dosage, the severity of symptoms was greater in vaccine recipients. Fourfold serum hemagglutination-inhibiting antibody titer rises occurred in 38% of vaccine recipients, and four vaccines had fourfold titer rises of nasal hemagglutination-inhibiting antibody. Vaccine virus was isolated from three asymptomatic vaccine recipients. There was no virological or serological evidence of the vaccine virus spreading to placebo recipients.


Precipitating antibodies in mycoplasma infection. The effectiveness of counterimmunoelectrophoresis (CIEP) for detecting human precipitating antibodies to mcyoplasma antigen was compared with the conventional complement fixation (CF) method in a double-blind experiment. Fifty-one sera from patients suspected of having acute mycoplasma infection were tested by both techniques. Dense precipitin lines to mycoplasma antigen developed in 28 sera with CIEP. Twenty-six of 28 had elevated CF titers to this antigen. No precipitin bands were observed in sera with low antibody titers to mycoplasma. These findings indicate that the CIEP test is a specific method for reliably detecting elevated serum CF antibody levels in patients with acute or recent mycoplasma infection.


Isolation of Francisella tularensis from infected frozen human blood. Francisella tularensis was isolated from human blood that was frozen for 3 months before it was examined. Before he became ill, the patient operated a "bush-hog" in an area thickly populated with rabbits. His illness was undiagnosed and untreated before his death. Portions of blood and tissue homogenates from necropsy were injected intraperitoneally into mice and inoculated onto glucose-cysteine-blood agar plates. F. tularensis did not grow from the culture plates, but mice inoculated with the blood died in 48 to 72 h. Fluorescent-antibody stains of mouse liver and spleen impression smears showed clumps of cells or amorphous masses of brightly staining envelope material around the cells. Tissue impressions of liver, spleen, and heart blood inoculated onto glucose-cysteine-blood agar yielded pure cultures of F. tularensis.


Selective and enhanced recovery of group A and B streptococci from throat cultures with sheep blood agar containing sulfamethoxazole and trimethoprim. Sheep blood agar containing 23.75 microgram of sulfamethoxazole and 1.25 microgram of trimethoprim (SXT-BA) per ml was compared with conventional sheep blood agar (SBA) for isolating group A and B streptococci from throat cultures. This selective medium allowed much better recovery of group A and B streptococci and suppressed the growth of the normal flora, including "viridans" streptococci. In an initial study of 700 throat cultures, SXT-BA recovered 42% more group A and 49% more group B streptococci than did SBA. When SXT-BA was introduced into the routine microbiology laboratory and used by a number of medical technologists. SXT-BA recovered 28% more group A and 37% more group B streptococci than did SBA. In addition, the selective medium inhibited 83% of the non-group A and B streptococci that were recovered by SBA.


Rapid urease test for mycobacteria: preliminary observations. A rapid and sensitive urease test for mycobacteria utilizing a cumulative radiometric technique is described. Definitive results were obtained within a 30-min incubation period. The procedure is simple and economical. Technical time involved is no greater than in conventional procedures.


An inexpensive device for evacuating and gassing anaerobic systems with in-house vacuum. An inexpensive, compact device to aid in establishing an anaerobic environment for bacterial cultures is described. This device is designed for use with an in-house vacuum system and can replace the vacuum pump, "U" utbe manometer system commonly used for this purpose.


Biochemical characterization of anaerobic bacteria by an impregnated disk method. An impregnated disk method was used to characterize 20 clinical isolates of anaerobic bacteria by utilization of substrate. The procedure was easy to perform, reliable, and economical.


Laboratory evaluation of a rapid four-hour serological grouping of groups A,B,C, and G beta-streptococci by the Phadebact streptococcus test. Grouping of beta-hemolytic streptococcal isolates by staphylococcal coagglutination was performed with the Phadebact Streptococcus Test to determine whether such isolates could be accurately grouped serologically with 4 h after examination of the primary isolation plates. Of 132 clinical isolates, 131 were correctly grouped by the Phadebact method using the Lancefield precipitation method as the accepted standard. Of the correctly grouped streptococci, 119 were definitively grouped within 4 h after examination of the primary plates, and the remaining 12 isolates were grouped within 24 h. Since the Phadebact Streptococcus Test contains coagglutination reagents for groups A, B, C, and G, those isolates that failed to react were considered as positive for groups other than the four included in the test system. There were 23 such isolates in this study. Lancefield grouping of these isolates indicated that nine were group F, five were group D, and the remaining nine were not groupable with the Lancefield reagents employed in this study. The one Phadebact "failure" involved an isolate that produced a 4 + reaction with the Phadebact group A reagent and a 4 + reaction with Lancefield group F reagent.


CAMP-disk test for presumptive identification of group B streptococci. The modification of the CAMP test for goup B streptococci involved substituting a paper disk impregnated with partially purified beta-hemolysin for the staphylococcal culture that was the source of beta-hemolysin in the original test. The disk is placed onto a sheep blood agar plate beside the streak of Streptococcus being tested. The plate is then incubated aerobically at 35 degrees C. A positive reaction consists of a lunar-shaped clear zone that appears within 24 h in the dark beta-hemolysin zone surrounding the disk. A double-blind study of 135 randomly coded streptococcal isolates showed complete agreement between the CAMP-disk test and the standard Lancefield precipitin test. All group B streptococci tested had positive reactions, and all strains tested from streptococcal groups A, C, D, and G were negative. The CAMP-disk test is a simple and convenient way to identify presumptively group B streptococci.


Comparison of coagulase, deoxyribonuclease (DNase), and heat-stable nuclease tests for identification of Staphylococcus aureus. One thousand and thirty-five clinical isolates of the genus staphylococcus were used to compare the coagulase test with the deoxyribonuclease (DNase) and heat-stable nuclease tests as methods for identifying Staphylococcus aureus. Conflicting results were obtained with 65 isolates when the coagulase test was compared with the DNase test but with only one isolate when the coagulase test was compared with the heat-stable nuclease test. The heat-stable nuclease test produced reliable results after four hours' incubation and was considered a satisfactory substitute for the coagulase test in the clinical laboratory.


Recovery of anaerobic bacteria from small inocula: a model for blood culture studies. The recovery of anaerobic, facultative anaerobic, and aerobic pathogens from very small inocula was studied under conditions that could be related to routine blood culture procedures. Results with Brain Heart Infusion broth were unsatisfactory. Freshly prepared Brewer thioglycollate medium gave apparently good results, but there are disadvantages when this medium is used for blood culture. Results with Difco Thiol broth were disappointing. A modification of Robertson's cooked-meat broth supplemented with Brain Heart Infusion gave good recovery and sustained viability with a wide range of test organisms including exacting strains. The findings raise points of practical importance.


Multiplication of contaminant bacteria in urine and interpretation of delayed culture. A prospective study of the bacterial populations of non-infected urine was mounted in an attempt to define the length of delay between voiding and analysis during which culture would not give false positive results due to the multiplication of contaminant bacteria present at the time of voiding. The findings suggest that culture of urine within four hours of voiding is likely to give a true indication of the presence or absence of infection. With further delay the interpretation of a heavy growth of bacteria in urine becomes progressively more unreliable, even if that growth is in pure culture.