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Biomedical subjects

T W Huber

Publications and source records attributed to T W Huber.

At least 19 recordsLinked to original sources
PubMed1994

Detection of resistance due to inducible beta-lactamase in Enterobacter aerogenes and Enterobacter cloacae.

Thirty-six of 36 strains of Enterobacter cloacae and E. aerogenes with inducible beta-lactamase developed resistance when cefoxitin (inducer) was added to cefuroxime disks. Constitutive beta-lactamase producers (n = 23) were all resistant to cefuroxime. Cefuroxime resistance correlated with the amount of induced or constitutive beta-lactamase. Cefuroxime was a better indicator of induced resistance than cefamandole, cefazolin, cephalothin, ceftriaxone, cefotaxime, ticarcillin with or without clavulanic acid, or cefotetan. Induction by addition of cefoxitin to disks occasionally reduced zone sizes but not enough to change interpretations for ceftazidime, ceftizoxime, aztreonam, cefoperazone with or without sulbactam, and piperacillin with or without tazobactam. Most enterobacters were resistant to cefmetazole. The cefoxitin inducer-cefuroxime indicator method can be used in routine clinical laboratories to detect latent resistance due to chromosomally mediated inducible beta-lactamase in enterobacters.

Cefuroxime↗
PubMed1994

Antimicrobial resistance of bacterial pathogens at two tertiary-care centers, in Riyadh and Texas.

Antimicrobial resistance of bacterial pathogens usually varies from one geographic location to another. During the last 20 years, outbreaks of disease caused by multiresistant bacteria have occurred with higher frequency in developing countries. We investigated the antimicrobial resistance patterns of bacteria isolated in 1992 from two tertiary-care centers, in Riyadh and Texas. Of the 8841 strains used, 5318 were isolated from clinical specimens of patients at King Faisal Specialist Hospital and Research Centre, Riyadh, and 3523 were from Olin E. Teague Veterans Medical Center, Temple, Tex. Members of Enterobacteriaceae at the King Faisal hospital were significantly more resistant to frequently prescribed antimicrobials than were those at the Olin Teague center. Susceptibility to less frequently used agents like ciprofloxacin and ceftazidime was similar at both hospitals. Resistance patterns of Pseudomonas aeruginosa, Haemophilus influenzae, and coagulase-negative staphylococci were similar at both medical centers. The Olin Teague center encountered significantly more methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci.

Developing Countries↗
PubMed1987

Evaluation of an immunochemical test for faecal occult blood in screening for colorectal neoplasia in a high risk group.

A group of 1615 asymptomatic individuals presumed to be at increased risk of colorectal neoplasia were selected as the study group. All were tested by an immunochemical test for faecal occult blood. In the second half of the study, individuals who were occult blood negative were offered colonoscopy. Ninety-nine individuals (6.1%) returned stools which were occult blood positive. Investigation by full colonoscopy was possible in 90 cases, revealing nine patients (10%) with invasive cancers, four patients (4.4%) with carcinomata in situ, and 36 patients (40%) with adenomata. Non-neoplastic pathology capable of producing occult blood positive stools was found in 31 individuals (34.4%). No pathology was found in 10 instances (11.1%). Of the 53 occult blood negative subjects who underwent colonoscopy, eight were found to have adenomata. Only one of these was larger than 5 mm in diameter (18 mm). No carcinomata were found. The site within the large bowel of the tumour did not appear to significantly affect the occult blood status of the faeces but the size of the tumours detected suggests that the presence of blood within the stool is more likely to be associated with larger lesions. The frequency of detection of both carcinomata and adenomata was greatest in individuals who had a past history of colorectal neoplasia. The individual cost of this immunochemical test is nominal. The high diagnostic yield and low false positive and negative rates suggest that case follow-up, surveillance, or screening utilizing this test is justified.

Adult↗
PubMed1985

A case of coccidioidomycosis diagnosed by exoantigen testing.

A case of coccidioidomycosis is described which was caused by a pigmented fungus that failed to produce arthroconidia. Exoantigen testing showed that the isolate produced an antigen that gave a line of identity with Coccidioides (C.) immitis. The formation of spherules in a guinea pig testis confirmed the identity of the isolate as C. immitis. The patient's serum was found to have antibodies that reacted in complement fixation and immunodiffusion tests to C. immitis antigens. The exoantigen test results were responsible for the diagnosis of coccidioidomycosis in this case.

Aged↗
PubMed1985

The automicrobic system for detection of bacteriuria. Efficacy of revised urine identification cards.

The results of clinical urine specimens tested in the Vitek AutoMicrobic System (AMS) using two different urine identification (UID) cards were compared with the results obtained by a quantitative culture method. AMS injector UID card results were evaluated with the use of 1,136 consecutive clinical specimens collected March 4 to May 23, 1983. Revised AMS UID cards were used to test 1,634 clinical specimens from November 8, 1983, to March 2, 1984. The revised UID card was less sensitive, more specific, had a greater predictive value for positive results, and had greater accuracy than the injector UID card in detecting organisms in urine. The revised urine card accurately quantified organisms in 90.1% of specimens versus 85.1% in injector cards. The revised card was superior in the predictive value of positive identification of urinary pathogens. Ninety percent of all organisms were identified within nine hours with either card. Improved accuracy of the revised cards makes it practical to electronically report automated urine screening results (detection, quantitation, and preliminary identification of urinary pathogens) by interfacing the AMS with hospital information systems.

Autoanalysis↗
PubMed1985

An assessment of an immunochemical test for human haemoglobin in the detection of colonic polyps.

It is now widely accepted that malignant tumours of the colon and rectum almost invariably arise from pre-existing adenomatous polyps. If such polyps could be detected and removed colonoscopically before they become malignant, theoretically the incidence of invasive colorectal cancer could be dramatically reduced. The purpose of this study was to determine whether an immunochemical test for faecal occult blood would identify patients with benign colonic polyps. The faecal samples from 121 patients scheduled to undergo colonoscopy were tested by our immunochemical method and the Hemoccult II test. There were nine patients who had malignant colorectal tumours. These were excluded from this study. Twenty-nine were found to have colonic polyps. Fifteen of these had one or more faecal samples which were positive by the immunochemical test. In contrast, there was only one patient who had a positive Hemoccult II test. Fourteen of the remaining 83 patients had positive immunochemical tests. The findings on colonoscopy provided satisfactory explanations in all these cases. Polyps of all sizes and histological type were associated with positive immunochemical tests. It is concluded that the immunochemical test has sufficiently high sensitivity for colonic polyps to make feasible the screening of patients at high risk of developing colonic cancer.

Colonic Polyps↗
PubMed1983

Comparison of an enzyme-linked immunosorbent assay with indirect hemagglutination and hemagglutination inhibition for determination of rubella virus antibody: evaluation of immune status with commercial reagents in a clinical laboratory.

Comparative evaluations of immune status for rubella virus are described for enzyme-linked immunosorbent assay, hemagglutination inhibition, and indirect hemagglutination. A 92.1% agreement between enzyme-linked immunosorbent assay and indirect hemagglutination assay was demonstrated for rubella immune status. Enzyme-linked immunosorbent assay and hemagglutination inhibition demonstrated a 92.6% agreement and were compared in an attempt to define the quantitative usefulness of comparisons of single sera for determining immune status. These data support the relative lack of correlation between single enzyme-linked immunosorbent assay and hemagglutination inhibition quantitative values. Enzyme immunoassay was, however, an acceptable alternative to hemagglutination inhibition for the determination of immune status to rubella virus.

Antibodies, Viral↗
PubMed1983

Reactivity of microhemagglutination, fluorescent treponemal antibody absorption, Venereal Disease Research Laboratory, and rapid plasma reagin tests in primary syphilis.

Seroreactivity of sera from 109 patients with first-infection primary syphilis was 98.2% in the fluorescent treponemal antibody absorption test, 92.7% in the rapid plasma reagin 18-mm circle card test, 72.5% in the microhemagglutination test (MHA-TP), and 72.5% in the Venereal Disease Research Laboratory test. Seroreactivity of sera from 18 patients with primary syphilis with documented previous infection(s) was 100% in the fluorescent treponemal antibody absorption test, the rapid plasma reagin 18-mm circle card test, and the MHA-TP test and 88.9% in the Venereal Disease Research Laboratory test. The MHA-TP test failed to confirm reactivity in 13 of 79 sera which were reactive in the Venereal Disease Research Laboratory test and in 24 of 101 sera which were reactive in the rapid plasma reagin 18-mm circle card test. Testing another production lot of MHA-TP reagents resulted in even poorer correlation. The reactivity of the MHA-TP test in primary syphilis appeared to vary with the sensitivity of the production lot of reagents.

Fluorescent Antibody Technique↗
PubMed1980

Reactivity of microhemagglutination, fluorescent treponemal antibody absorption, and venereal disease research laboratory tests in primary syphilis.

Seroreactivity in 130 cases of primary syphilis was 91.5% by fluorescent treponemal antibody absorption test, 82.3% by microhemagglutination (MHA-TP test), and 68.5% by the Venereal Disease Reseach Laboratory (VDRL) test. The MHA TP test generally became reactive earlier than the VDRL test and confirmed all reactive and most weakly reactive VDRL results.

Antibodies, Bacterial↗
PubMed1979

Diagnosis of toxoplasmosis by electron microscopic fine-structural analysis.

The analysis of fine structures by electron microscopic examination of ultrathin tissue sections permitted a diagnosis of toxoplasmosis in a fatal human case that would have gone undiagnosed by conventional methods. Examination of histologically prepared sections revealed organisms that were morphologically nondiagnostic. Fine-structural analysis showed the organisms to be 3 x 2 micrometer in size, to contain few micronemes, to contain as many as nine rhoptries, to possess an apical conoid, and to multiply by endodyogeny. The features corresponded to those observed in fine-structural analyses of Toxoplasma gondii grown in animals by Scholtyseck and Mehlhorn. Fine-structural analysis can be a valuable adjunct in the diagnosis of toxoplasmosis.

Cell Division↗
PubMed1978

Method for evaluating broth culture media: application to Haemophilus.

A method was devised to test the growth-promoting ability of a broth medium. The "dilute to extinction" method determines the inoculum required to develop heavy turbidity in a broth with overnight incubation. A statistical method using Poisson distribution was used to show that a single Haemophilus cell can develop heavy turbidity in an optimal broth. The dilute to extinction method was used to evaluate the shelf life of stored media, to titrate the growth factor requirements of Haemophilus, and to evaluate the use of purified hemin and nicotinamide adenine dinucleotide in a broth medium for the growth of Haemophilus. Of the media tested, the most suitable formulation was Mueller-Hinton broth supplemented with 10 microgram of hemin and 10 microgram of nicotinamide adenine dinucleotide per ml. The dilute to extinction method appears to be especially useful in the development of broth media for fastidious organisms. The method could also be used to assure the quality of other broth media which are required to support the growth of small inocula in the clinical or research laboratory.

Culture Media↗
PubMed1978

Mycobacterium terrae synovitis and osteomyelitis.

An immunocompromised patient with Mycobacterium terrae synovitis and osteomyelitis is presented. Therapeutic recommendations are made based upon existing knowledge of the pathogenesis, course, and outcome of similar infections with nontuberculous mycobacteria.

Adult↗
PubMed1977

Feasibility of screening for penicillinase-producing Neisseria gonorrhoeae from primary culture plates by using a rapid microacidometric test.

We have shown that it is possible to screen for penicillinase-producing Neisseria gonorrhoeae directly from primary culture plates. Experiments involving the cocultivation of four genera of beta-lactamase-positive (beta-lac(+)) bacteria and a beta-lactamase-negative (beta-lac(-)) N. gonorrhoeae on modified Thayer-Martin medium indicated that suppressed or inhibited beta-lac(+) bacteria did not give false-positive results when isolated beta-lac(-) colonies of gonococci were tested. Colonies were assayed for beta-lac production by an adaptation of a microacidometric method in which bacteria could be tested before or after the addition of oxidase reagent.

Bacteriological Techniques↗
PubMed1977

Growth of cell wall-defective variants of Escherichia coli: comparison of aerobic and anaerobic induction frequencies.

A method for quantitating the conversion of Escherichia coli to colony-forming, cell wall-defective (CWD) bacteria has been developed. The induction frequency, i.e., the percentage of the population recovered as CWD colonies was determined for 20 randomly selected clinical isolates of E. coli under aerobic and anaerobic incubation conditions. Penicillin (1,000 U/ML) was the inducing agent. The 20 strains segregated into three groups. Group I organisms produced CWD colonies with high frequency both aerobically and anaerobically. Grout II organisms showed a much higher induction frequency anaerobically than aerobically. Group III organisms were poor inducers. Thirty percent of the strains were group I, 50% were group II, and 20% were group III organisms. These data indicate that anaerobic conditions enhance the induction and growth of CWD E. coli in the research laboratory and suggest that anaerobic incubation may be important in recovery of medically significant CWD bacteria.

Aerobiosis↗
PubMed1976

The isolation of Vibrio parahaemolyticus and related vibrios from moribund aquarium lobsters.

Vibrios were isolated in pure culture from the hemolymph of 7 out of 28 dead or dying aquarium lobsters which had been acclimated to 20-22 degrees C. One isolate was identified as Vibrio parahaemolyticus, one as a related marine Vibrio (probably V. marinus), and five as Vibrio alginolyticus. No isolates of halophilic Vibrio species were made from healthy lobsters using thiosulfate citrate bile salts sucrose agar (TCBS).

Animals↗