Host-parasite relationships in experimental airborne tuberculosis. VII. Fate of Mycobacterium tuberculosis in primary lung lesions and in primary lesion-free lung tissue infected as a result of bacillemia.

Evidence suggests that in humans tuberculous disease usually arises at apical or subapical sites in the lungs seeded as a consequence of an early bacillemic phase of the infection. This study examined the fate of bacilli transported via the bloodstream to metastatic sites in the lungs of guinea pigs after aerosol infection with approximately two viable virulent Mycobacterium tuberculosis. The results revealed that, even after logarithmic-phase multiplication of bacilli in primary lesions had been terminated, bacilli seeded via the bloodstream to metastatic sites in the lung were able to multiply.

Towards optimum blurring in spiral tomography.

Attempts to increase the degree of blurring of nonfocused layers in tomography are inevitably associated with a worsening in the amount of artefactual detail introduced. A mathematical optimization technique has been employed to indicate how these conflicting characteristics may best be reconciled. The technique uses plausible definitions, based on the transfer function, of the effectiveness and the fidelity of the blurring, and generates a sequence of spread functions in which these two aspects are optimally combined.

Anaerobic and aerobic urethral flora in healthy females.

We characterized the aerobic and anaerobic urethral flora of five healthy females by performing urethral and midstream urine cultures once weekly for 8 weeks. Aerobic cultures were performed monthly for an additional 3 months. Lactobacillus spp.

Mechanism of steroid binding to serum proteins.

Association and dissociation rate constants of steroid complexes with progesterone-binding globulin (PBG) and with corticosteroid-binding globulin have been determined, utilizing the fluorescence quenching phenomenon observed on steroid binding to protein. Stopped-flow techniques were used in most cases. The dissociation rates of the complexes with steroid-binding proteins of serum are much greater than those of steroid-receptor complexes, in accordance with the biological functions of these two types of proteins.

Prospective comparison of cefoxitin and cefazolin in infections caused by aerobic bacteria.

Intravenous cefazolin and cefoxitin were compared in a prospective randomized trial in infections where the suspected pathogen was expected to be susceptible to both antibiotics. In the cefazolin group (12 patients) the diagnosis was pneumonia in 4, including 2 with pneumococcal bacteremia, soft tissue infection in 5, Staphylococcus aureus bacteremia in 1, acute pyelonephritis in 1, and disseminated gonococcal infection in 1. In the cefoxitin group (10 patients) the diagnosis was pneumonia in 4, including 2 with pneumococcal bacteremia, soft tissue infection in 4, acute pyelonephritis in 1, and disseminated gonococcal infection in 1.

Kinetic and equilibrium studies on steroid interaction with human corticosteroid-binding globulin.

Kinetic and equilibrium studies on the interaction of steroids with human corticosteroid-binding globulin (CBG, transcortin) were performed with pH, temperature, and steroid structure as variables. Dissociation rate constants were determined fluorometrically; the values for cortisol, corticosterone, deoxycorticosterone, and progesterone are 0.031, 0.

Granulocytopenia in hospitalized patients. II. A prospective comparison of two antibiotic regimens in the empiric therapy of febrile patients.

The results of empiric antibiotic therapy in 126 hospitalized patients with fever during 192 episodes of granulocytopenia were studied. Febrile granulocytopenic patients were randomly allocated to receive either carbenicillin, methicillin and gentamicin, or carbenicillin and cephalothin. The response rate for the two antibiotic regimens was similar, 49 (60 per cent) of 81 responded to the former and 42 (54 per cent) of 78 to the latter.

Granulocytopenia in hospitalized patients: I. Prognostic factors and etiology of fever.

The clinical course of 126 hospitalized patients during 192 episodes of granulocytopenia and fever was studied. Fever was a regular accompaniment of granulocytopenia, occurring in 94 per cent of granulocytopenic episodes. The mean duration of granulocytopenia (less than 1,000/mm3) was 18 days, with fever (temperature greater than 38 degrees C) being present during 44 per cent of those days.

Stimulus intensity effects in electrodermal habituation.

Experiment 1 presented human subjects with 25 shocks of the same (.5, 1.5, or 2.

Host-parasite relationships in experimental airborne tuberculosis. VI. Influence of vaccination with Bacille Calmette-Guérin on the onset and/or extent of hematogenous dissemination of virulent Mycobacterium tuberculosis to the lungs.

Guinea pigs vaccinated with bacille Calmette-Guérin (BCG) and unvaccinated guinea pigs were challenged by the respiratory route six weeks or six months after vaccination and sacrificed at various intervals after challenge. The six lobes of the lung were cultured separately, and the percentage of culture-positive lobes was calculated, as well as the log10 number of virulent bacilli recovered. The latter was subjected to an analysis of variance, which compared the fate of bacilli in the four largest lobes with the fate of those in the two smallest lobes.

Optimum spread functions in linear tomography.

Recent attempts to reduce artefacts in tomographic blurring, using a transfer function approach, have so far taken little explicit account of the lessening in the degree of blurring which accompanies transfer function correction. A simple comparative measure R of the blurring effect of a linear tomographic movement is proposed. The parameter R is related to the ratio of the area of the point spread function (PSF) to its peak height.

Amoxicillin therapy of acute urinary infections in adults.

Fifty-two patients, 48 females and 4 males, with suspected urinary infection were treated with amoxicillin. Twenty-two females with presumed bladder infection were treated with amoxicillin, 250 mg three times a day for 7 days; 26 females and 4 males with presumed renal infection were treated with amoxicillin, 500 mg three times a day for 14 days. Five patients were immediate treatment failures, with positive urine cultures during therapy.

Bacteremia due to Bacteroidacceae: a review of 92 cases.

The clinical courses of 92 patients who had bacteremia due to Bacteroidaceae were reviewed. The overall mortality rate was 21% (19 patients). There was no significant difference between mortality rates when patients were grouped by anticipated clinical course of underlying disease (nonfatal, ultimately fatal, and rapidly fatal) and when they were grouped by type of antibacterial therapy (appropriate, including clindamycin, chloramphenicol, lincomycin, and carbenicillin; or inappropriate, signifying no antibiotic treatment or treatment with antibiotics other than the four listed above).

Approaches to the validation of animal test systems for assay of protective potency of BCG vaccines.

Three animal test systems, two in guinea-pigs and one in mice, have been examined to differentiate the ability of three BCG vaccines with respect to their ability to protect the animals against infection when challenged with virulent bacilli. One test system showed great promise and was examined in greater detail in order to explain the mechanism of protection. These studies are continuing in order to test a series of BCG vaccines that will be given to groups of children and their protective effect observed.

Blurring quality in spiral tomography.

In view of the close relationship which exists between image aberrations and the form of the transfer function, the transfer functions of some different types of spiral tomographic movements have been calculated numerically. The results allow prediction of a type of spiral movement which yields blurring of favourable quality. The validity of this approach has been demonstrated experimentally, by comparing the blurring characteristics of tomographs with single and multiple circular movements.

Characterization of bacteroides melaninogenicus.

Fifty-eight human isolates of Bacteroides melaninogenicus, 42 from a variety of clinical infections and the rest from normal flora, were studied for pigment production and ultraviolet light fluorescence and by forty biochemical and other tests, including end-product analysis by gas-liquid chromatography. In a number of instances, tests were repeated several times and the results were reproducible. Agar plate dilution susceptibility tests were also performed to 12 antimicrobial agents.

Host-parasite relationships in experimental airborne tuberculosis. V. Lack of hematogenous dissemination of Mycobacterium tuberculosis to the lungs in animals vaccinated with Bacille Calmette-Guérin.

The influence of bacille Calmette-Guérin (BCG) on the pathogenesis of experimental airborne tuberculosis was studied. In a model that approximates the conditions under which man is vaccinated and infected, BCG-vaccinated and unvaccinated guinea pigs were infected by the respiratory route with an inoculum that resulted in the inhalation and retention (by each animal) of approximately three virulent tubercle bacilli (Mycobacterium tuberculosis strain H37Rv). Hematogenous seeding of the lungs occurred in unvaccinated animals about three weeks after aerosol infection but did not occur in BCG-vaccinated animals.