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Biomedical subjects

F Stock

Publications and source records attributed to F Stock.

33 records · Page 2Linked to original sources
PubMed1993

Rapid method for presumptive identification of Corynebacterium jeikeium.

Corynebacterium jeikeium causes systemic infections, particularly in immunocompromised hosts. A minitube assay has been developed for the presumptive identification of C. jeikeium. With our rapid sucrose-urea test and conventional biochemical tests, sixty isolates of gram-positive, catalase-positive bacilli were identified in our laboratory. Results indicated that our assay has a sensitivity of 100% and a specificity of 90%.

Algorithms↗
PubMed1992

Pneumocystis carinii and specific fungi have a common epitope, identified by a monoclonal antibody.

Because Pneumocystis carinii may be related to fungi, we evaluated the reactivities of monoclonal antibodies raised against P. carinii with a variety of fungi. Fifty-two fungi and six protozoa were evaluated by immunofluorescence. One of three monoclonal antibodies (MAbs) tested (MAb 7D7) reacted with 15 fungi but no protozoa. Saccharomyces cerevisiae showed the strongest reactivity by immunofluorescence. The reactive antigen was characterized for four fungi by the immunoblot technique. In all cases the antigen that was reactive with MAb 7D7 was larger than the P. carinii antigens that reacted with 7D7. In further studies with P. carinii, Aspergillus species, and S. cerevisiae, we found that MAb 7D7 reacted with a carbohydrate component in all organisms. The presence of an epitope that is common to P. carinii and a number of fungi further supports the fungal nature of P. carinii.

Antibodies, Monoclonal↗
PubMed1992

Diagnosis of Pneumocystis carinii pneumonia by multiple lobe, site-directed bronchoalveolar lavage with immunofluorescent monoclonal antibody staining in human immunodeficiency virus-infected patients receiving aerosolized pentamidine chemoprophylaxis.

The yields of both induced sputum examination and bronchoalveolar lavage (BAL) have been reported to be decreased for breakthrough episodes of Pneumocystis carinii pneumonia in human immunodeficiency virus-infected patients receiving aerosolized pentamidine chemoprophylaxis. This study assessed whether the yield of a single middle or lower lobe BAL could be increased by the utilization of two techniques: (1) indirect immunofluorescent staining with a combination of two murine monoclonal anti-Pneumocystis antibodies in addition to routine toluidine blue O and cytopathologic staining, and (2) the performance of multiple lobe, site-directed BAL (i.e., both upper lobe and middle or lower lobe lavage, including the lobe with the greatest radiographic abnormality). Results of 252 fiberoptic bronchoscopies performed at the National Institutes of Health and the Los Angeles County-University of Southern California Medical Center were analyzed. P. carinii pneumonia was documented in 21 episodes in patients who did not receive prior anti-Pneumocystis chemoprophylaxis and in 41 episodes in patients who received aerosolized pentamidine. Monoclonal antibody staining and multiple lobe, site-directed BAL resulted in similar diagnostic yields for P. carinii in the nonprophylaxis (100%) and aerosolized pentamidine (98%) groups. If BAL had been performed without monoclonal antibody staining and multiple lobe, site-directed lavage, then the yield would have decreased to 95% in the nonprophylaxis group and to 80% in the aerosolized pentamidine group.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Opportunistic Infections↗
PubMed1988

Optimal use of the cytocentrifuge for recovery and diagnosis of Pneumocystis carinii in bronchoalveolar lavage and sputum specimens.

To facilitate the diagnosis of Pneumocystis carinii from bronchoalveolar lavage and sputum specimens, we have defined conditions for optimal use of the cytocentrifuge for this purpose. Centrifugation in the cytocentrifuge at 1,200 rpm for 10 min yielded the best recovery of P. carinii. To reliably ensure complete absorption of the fluid specimen from the cytocentrifuge chamber, it was necessary to use two absorption filters simultaneously. Different methods of treating induced sputum with mucolytic agents to process sputum with the cytocentrifuge were tried. Results of these studies and our current method for treating sputa are discussed. Comparisons of slides prepared by traditional centrifugation and by cytocentrifuge processing showed the latter to be equally effective for detecting P. carinii. The most prominent advantage of the cytocentrifuge was the much smaller area to review and consequently the shortened time required to read the slides.

Animals↗
PubMed1987

Detection of Mycobacterium avium-Mycobacterium intracellulare in blood cultures using concentrated and unconcentrated blood in conjunction with a radiometric detection system.

Studies were performed in order to determine optimal methods for isolating mycobacteria from blood. The combined use of a lysis-centrifugation (Isolator) system and a radiometric-detection system (Bactec) was compared to the use of either unconcentrated blood or centrifuged blood pellet in conjunction with the Bactec mycobacterial system. Results showed that for cultures with greater than 10 colony forming units (CFU) per ml of blood, the use of unconcentrated blood and centrifuged blood pellet was as sensitive as use of the Isolator concentrate. For cultures with lower colony counts (less than 10 CFU/ml), however, Isolator concentrate was consistently better than either centrifuged or unconcentrated blood. Since over half of our positive cultures had low colony counts, the use of Isolator concentrate inoculated into either a Bactec mycobacterial culture vial or onto Middlebrook agar slants is recommended over the use of either centrifuged blood pellet or unconcentrated blood inoculated into a Bactec mycobacterial culture vial.

Bacteriological Techniques↗
PubMed1987

Medium for the simultaneous detection of pyocyanin and fluorescein pigments of Pseudomonas aeruginosa.

To help simplify the identification of Pseudomonas aeruginosa by clinical microbiology laboratories, the authors developed a new medium, pyocyanin-fluorescein agar (PFA), which enhances the production of both Pseudomonas pigments simultaneously. Production of pigments on PFA was equivalent to production on a pyocyanin agar (P agar) and a fluorescein agar (F agar) used in combination and was superior to either P agar or F agar used alone. The medium is simple to prepare and it detected pigment in 94% of P. aeruginosa isolates tested.

Culture Media↗
PubMed1987

Detection of Pneumocystis carinii by fluorescent-antibody stain using a combination of three monoclonal antibodies.

A combination of three monoclonal antibodies, two prepared against human and one against rat Pneumocystis carinii, was used in an indirect fluorescent-antibody stain (IFA) to diagnose P. carinii in both bronchoalveolar lavage and lung biopsy specimens. This combination of monoclonal antibodies was specific for P. carinii and yielded bright fluorescence of both P. carinii cysts and trophozoites. A total of 126 specimens from 93 patients were stained for P. carinii by a toluidine blue O stain and the monoclonal IFA. Forty-five (35.7%) of these were positive for P. carinii by toluidine blue O, and 43 (34.1%) were positive by IFA. There was 98.4% agreement between both methods, with no false-positive and two false-negative occurrences by IFA. An IFA procedure with monoclonal antibodies such as those used in these studies can provide a simple, fast, and sensitive method for diagnosing P. carinii pneumonia by microbiology laboratories.

Acquired Immunodeficiency Syndrome↗
PubMed1986

[Clinical and instrumental evaluation by multiple colonic manometry of tiropramide, trimebutine and octylonium bromide in irritable colon. II. Repeated oral administration].

Sixty out-patients with acute or sub-acute irritable colon were randomly allocated to receive 3 daily doses of 100 mg tiropramide, 150 mg trimebutine maleate or 20 mg octilonium bromide, orally during 5 consecutive days. Before and after treatment, multiple colonic manometry was performed, monitoring tonus, intensity and frequency of sinusoid contraction waves, transitories and vibrations, as well as the voluntary contraction capacity. Before treatment and after 2 and 5 days, the specific symptoms were also monitored, scored and recorded. Significant variations in tonus were not observed with any drug, but while tiropramide left unmodified the voluntary contractile ability, a significant inhibition was observed with trimebutine and, mainly, with octilonium. The overall power of spontaneous colonic contractions did not vary significantly with any drug. However, while with tiropramide a significant redistribution of muscular power was observed so as to increase propulsion waves and to decrease the ineffective transitory and vibrational contractions, with octilonium and trimebutine no clinically relevant redistribution of the power wasted in transient spasms was observed. Based on these observations, tiropramide was considered to be at least as effective an antispasmodic as octilonium and at least as effective a synchronizer as trimebutine, but was different from both reference drugs because it was the only one to act simultanously as both an antispasmodic and a synchronizer. The three drugs produced an improvement in each and all monitored symptoms as well as in the overall symptom intensity. Tiropramide, however, produced an improvement significantly faster, more progressively and to a greater extent than either reference drug.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1986

[Clinical and instrumental evaluation by multiple colonic manometry of tiropramide, trimebutine and octylonium bromide in the irritable colon: I. Administration by single i.v].

Sixty out-patients with acute or sub-acute irritable colon were randomly allocated to receive a single intravenous dose of 50 mg tiropramide, 50 mg trimebutine maleate or 10 mg octilonium bromide. Before and after injection, multiple colonic manometry was performed, monitoring tonus, intensity and frequency of sinusoid contraction waves, transitories and vibrations, as well as the voluntary contraction capacity. Significant variations in tonus were not observed with any drug, but, while tiropramide left unmodified the voluntary contractile ability, a significant inhibition was observed with trimebutine and octilonium. The overall power of spontaneous colonic contractions did not vary significantly with tiropramide, whereas some decrease was observed with trimebutine, and a substantial one with octilonium. Moreover, while with tiropramide and, to a lesser extent, with trimebutine there was a significant redistribution of muscular power so as to increase phasic propulsion waves and to decrease the ineffective transitory and vibrational contractions, with octilonium only a decreased wave amplitude was recorded without alteration of the frequency of transient spasms. Based on these observations, tiropramide was evaluated as being at least as effective an antispasmodic as octilonium and at least as effective a synchronizer as trimebutine, while setting itself aside from both reference drugs as it was the only one to act contemporarily as both an antispasmodic and a synchronizer.

Adult↗
PubMed1985

Use of lysis-centrifugation (isolator) and radiometric (BACTEC) blood culture systems for the detection of mycobacteremia.

Patients with acquired immune deficiency syndrome may develop infection with mycobacteria, particularly Mycobacterium avium-M. intracellulare (MAI). These infections can frequently be associated with demonstrable mycobacteremia with the organism. In this study, we compared the sensitivity of a radiometric (BACTEC system; Johnston Laboratories, Inc., Towson, Md.) liquid medium culture system with that of conventional solid mycobacterial culture media for cultures of blood from these patients. Both systems were inoculated with blood concentrate prepared by lysis-centrifugation (Isolator; Du Pont Co., Wilmington, Del.). Of 46 acquired immune deficiency syndrome patients whose blood was cultured, 28% had cultures positive for MAI. Patients had from less than 1 to more than 100 MAI colonies per ml of blood. Lowenstein-Jensen and Middlebrook 7H11 agars were comparable in recovery of MAI. BACTEC 12A vials containing double the standard volume of medium (4 ml) were more sensitive and were positive slightly earlier than vials containing the standard volume (2 ml). Conventional media detected 98% of positive cultures; BACTEC vials containing double volumes of medium detected 94% of positive cultures, whereas single-volume vials detected 77%. BACTEC vials were positive approximately 5 to 6 days sooner than slants or plates containing conventional media. For a few cultures, the use of unconcentrated blood was compared with the use of Isolator-concentrated blood by using each of these as inocula for BACTEC vials. Results for these cultures suggested that, although the use of Isolator-concentrated blood resulted in greater sensitivity than the use of unconcentrated blood would, the use of unconcentrated blood would still result in the detection of at least 78% of positive cultures.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Comparison of lysis-centrifugation with lysis-filtration and a conventional unvented bottle for blood cultures.

Evaluation of a commercially available lysis-centrifugation blood culture system (Isolator, DuPont Co., Wilmington, Del.) and a lysis-filtration blood culture system for 3,111 cultures showed that both methods had comparable recoveries (73 and 68%, respectively) of significant aerobic and facultatively anaerobic isolates. The unvented conventional blood culture bottle had a recovery rate of 59%. Although the lysis-centrifugation and lysis-filtration systems had comparable recoveries of pathogens, the lysis-centrifugation system had the advantage of having colonies immediately available for further testing. The contamination rate with the lysis-centrifugation system was 3%, compared with 6% with the lysis-filtration system and 0.4% with brain heart infusion.

Bacteria↗
PubMed1983

Long-term management of duodenal ulcer with pirenzepine and cimetidine: a double-blind controlled clinical trial.

The effectiveness of pirenzepine in the prevention of duodenal ulcer relapses was assessed by means of a double-blind controlled trial versus cimetidine. Seventy duodenal ulcer out-patients endoscopically healed after a 6-week treatment with either pirenzepine or cimetidine were admitted to the trial. The former pirenzepine patients were treated again with pirenzepine: 1 tablet at breakfast and 2 tablets at bedtime (75 mg daily). The former cimetidine patients were treated again with cimetidine: 2 tablets at bedtime (400 mg daily). They received one placebo tablet at breakfast. Both treatments lasted 12 months. Tablets of a mild antacid were permitted only if necessary to relieve severe ulcer pain and heartburn. Patients underwent clinical and endoscopic assessments after 4, 8 and 12 months of treatment and whenever ulcer symptoms lasted more than 4-5 consecutive days. Only 47 out of the 70 patients that entered the trial underwent all clinical and endoscopic controls. Sixteen out of 23 patients on pirenzepine (70%) and 17 out of 24 patients on cimetidine (71%) did not relapse after 12 months. The difference is not statistically significant. Both treatments were well tolerated. The results show that pirenzepine was as effective as cimetidine in the prevention of duodenal ulcer relapses when administered at a dosage of 75 mg daily (of which 50 mg at bedtime) for one year.

Adult↗
PubMedDate not supplied

Lysis-centrifugation blood cultures in the detection of tissue-proven invasive candidiasis. Disseminated versus single-organ infection.

Several studies have demonstrated significantly higher frequency and more rapid detection of candidemia with blood culture methods performed by lysis-centrifugation (LC) in comparison with other techniques. Little is known, however, about the ability of LC blood culture methods to detect tissue-proven invasive candidiasis. We therefore investigated the sensitivity of LC blood cultures in the detection of tissue-proven invasive candidiasis. Between 1985 and 1991, invasive candidiasis was detected in 41 (5.1%) of 803 autopsies at the Clinical Center of the National Institutes of Health (Bethesda, MD, USA). Cases were classified as single-organ (SO) candidiasis (n = 20) and as disseminated candidiasis (DI) (n = 21). Patients with DI were more likely than those with SO to have a hematologic malignancy (71% vs 15%, P < 0.001) and to have gastrointestinal mucosal candidiasis (76% vs 25%, P = 0.003). LC detected fungemia in 16 (43%) of all 37 cases with blood cultures. When analyzed by classification, Candida spp. were isolated from blood in 11 (58%) of 19 patients with DI and in five (28%) of 18 patients with SO (P = 0.13). When analyzed by number of organs infected, blood cultures were positive in seven (78%) of nine patients with > 3 organs infected by Candida in comparison to five (28%) of 18 patients with one organ infected (P = 0.024). The mean recovery time for Candida in blood cultures was 2.6 days in DI and 3.2 days in SO (P = 0.017). There was no difference in colonies of organisms per LC tube between patients with DI and those with SO.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗