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Biomedical subjects

S Herman

Publications and source records attributed to S Herman.

At least 37 records · Page 2Linked to original sources
PubMed1999

Efficiencies of four versions of the AMPLICOR HIV-1 MONITOR test for quantification of different subtypes of human immunodeficiency virus type 1.

Three versions of a commercial human immunodeficiency virus (HIV) type 1 (HIV-1) load test (the AMPLICOR HIV-1 MONITOR Test versions 1. 0, 1.0+, and 1.5; Roche Diagnostics, Branchburg, N.J.) were evaluated for their ability to detect and quantify HIV-1 RNA of different genetic subtypes. Plasma samples from 96 patients infected with various subtypes of HIV-1 (55 patients infected with subtype A, 9 with subtype B, 21 with subtype C, 2 with subtype D, 7 with subtype E, and 2 with subtype G) and cultured virus from 29 HIV-1 reference strains (3 of subtype A, 6 of subtype B, 5 of subtype C, 3 of subtype D, 8 of subtype E, 3 of subtype F, and 1 of subtype G) were tested. Detection of subtypes A and E was significantly improved with versions 1.0+ and 1.5 compared to that with version 1. 0, whereas detection of subtypes B, C, D, and G was equivalent with the three versions. Versions 1.0, 1.0+, and 1.5 detected 65, 98, and 100% of the subtype A-infected samples from patients, respectively, and 71, 100, and 100% of the subtype E-infected samples from patients, respectively. Version 1.5 yielded a significant increase in viral load for samples infected with subtypes A and E (greater than 1 log10 HIV RNA copies/ml). For samples infected with subtype B, C, and D and tested with version 1.5, only a slight increase in viral load was observed (<0.5 log10). We also evaluated a prototype automated version of the test that uses the same PCR primers as version 1.5. The results with the prototype automated test were highly correlated with those of the version 1.5 test for all subtypes, but were lower overall. The AMPLICOR HIV-1 MONITOR Test, version 1.5, yielded accurate measurement of the HIV load for all HIV-1 subtypes tested, which should allow the test to be used to assess disease prognosis and response to antiretroviral treatment in patients infected with a group M HIV-1 subtype.

Evaluation Studies as Topic↗
PubMed1999

Use of PCR in detection of Mycobacterium avium complex (MAC) bacteremia: sensitivity of the assay and effect of treatment for MAC infection on concentrations of human immunodeficiency virus in plasma.

We evaluated the sensitivity and specificity of a PCR-based qualitative test for the rapid diagnosis of Mycobacterium avium-M. intracellulare complex (MAC) bacteremia in patients with AIDS disease. Eleven subjects with newly culture-proven MAC bacteremia had the following tests performed at biweekly intervals during the first 8 weeks of therapy: blood culture, Mycobacterium-specific PCR, and quantitative human immunodeficiency virus (HIV) viral-load testing. Mycobacterium genus-specific biotinylated primers were used to amplify a sequence of approximately 582 nucleotides within the 16S rRNA genes of M. avium and M. intracellulare. Detection of the amplified product was performed with an oligonucleotide probe-coated microwell plate combined with an avidin-horseradish peroxidase-tetramethylbenzidine conjugate-substrate system. While not as sensitive as BACTEC culture, PCR detected 17 of 18 specimens which grew >/=40 organisms/ml (94.4% sensitivity) and 9 of 16 specimens which grew </=40 organisms/ml (56.3% sensitivity). No clear change in HIV viremia occurred in response to successful treatment of patients' MAC bacteremia. Use of the PCR test allowed detection of MAC bacteremia in 1 day, with a sensitivity similar to those of quantitative blood culture techniques, and it may prove useful for rapid screening of suspected cases. HIV viremia was unaffected by 8 weeks of MAC therapy.

AIDS-Related Opportunistic Infections↗
PubMed1998

A study of the workforce in emergency medicine.

STUDY OBJECTIVE: Emergency medicine has progressed significantly since its initial recognition as a medical specialty. Relatively little factual information is known, however, regarding who or how many physicians practice emergency medicine. The purpose of this study is to determine the total number of physicians practicing clinical emergency medicine during a specified period, to describe certain characteristics of those individuals, and to estimate the total number of full-time equivalents (FTEs), as well as the total number of individuals needed to staff those FTEs. METHODS: Data were gathered from a survey of a random sample of 2,062 hospitals drawn from a population of 5,220 hospitals reported by the American Hospital Association as having, or potentially having, an emergency department. The survey instrument addressed items such as descriptive data on the institution, enumeration of physicians in the ED, as well as the total number working during the period June 1, 1997, through June 14, 1997. Demographic data on the individuals were also collected. RESULTS: A total of 942 hospitals responded (a 45.7% return rate). These hospitals reported a total of 5,872 physicians were working during the specified period, or an average of 7.48 persons scheduled per institution. The physicians were scheduled for a total of 297,062 hours. The average standard for FTE was 40 clinical hours per week. This equates to 3,713 FTEs or 4.96 FTEs per institution. The ratio of persons to FTEs was 1.51:1. With regard to demographics, 83% of the physicians were men and 81% were white. Their average age was 42 years. As to professional credentials, 58% were emergency medicine-residency trained and 53% were board certified in emergency medicine; 46% were certified by the American Board of Emergency Medicine. CONCLUSION: Given that there are 4,945 hospitals with EDs and given that the data indicate there are 4.96 FTEs per ED, the total number of FTEs is projected to be 24,548 (standard error = 437). Given further that the data indicate a physician/FTE ratio of 1.51:1, we conclude that there are 36,990 persons (standard error = 683) needed to staff those FTEs. When adjusted for persons working at more than one ED, that number is reduced to 32,026.

Adult↗
PubMed1998

Absolute copy number and relative change in determinations of human immunodeficiency virus type 1 RNA in plasma: effect of an external standard on kit comparisons.

Use of a common set of human immunodeficiency virus type 1 (HIV-1) RNA standards eliminated differences among absolute HIV-1 RNA copy number estimates made with three commercially available assays. The relative changes in the viral RNA levels determined by the commercial assays were similar and were unaffected by the use of a common set of standards.

Female↗
PubMed1998

Ultrasensitive reverse transcription-PCR assay for quantitation of human immunodeficiency virus type 1 RNA in plasma.

With the recent introduction of combination therapy, human immunodeficiency virus type 1 (HIV-1) RNA levels in plasma have been dramatically reduced, frequently to below the limit of quantitation (400 copies/ml of plasma) of the AMPLICOR HIV-1 MONITOR Test (Roche Diagnostic Systems). To achieve enhanced sensitivity of the AMPLICOR HIV-1 MONITOR Test, a modified specimen preparation procedure that allows input of RNA from 10-fold more plasma per amplification reaction was developed. This "ultrasensitive" method allows the accurate quantitation of plasma HIV-1 RNA levels as low as 50 copies/ml. A precision study yielded average within-run and between-run coefficients of variation (CV) of 24.8 and 9.6%, respectively. A multicenter reproducibility study demonstrated that the laboratory-to-laboratory reproducibility of this assay is good, with an average CV of 32%. The linear range of this test is between 50 and 50,000 copies/ml of plasma. RNA concentrations measured by the ultrasensitive and standard HIV-1 MONITOR tests exhibited good agreement within the shared linear range of the two methods. The two measurements were within a factor of 2 for 91% of the specimens tested, with the concentration measured by the ultrasensitive method being only slightly lower (median, 22% lower). Preliminary studies suggest that this assay will prove to be useful for predicting the stability of viral suppression in patients whose RNA levels drop below 400 copies/ml in response to highly active antiretroviral therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Pulmonary arteriography for the assessment of technical feasibility of sleeve resection in lung cancer.

BACKGROUND: Pulmonary arteriography has been reported to be useful in the preoperative assessment of patients with lung cancer to determine the technical resectability and feasibility of pneumonectomy by imaging the main right and left pulmonary arteries. In this report, we describe the use of selective pulmonary arteriography in the assessment of lobar resectability. METHODS: Selective pulmonary arteriography provides a detailed anatomic view of the lobar branches and has been used at our institution for the past 30 years to preoperatively investigate patients who are candidates for a sleeve lobectomy. RESULTS: Three cases are described that demonstrate the usefulness of selective pulmonary arteriography in the assessment of the technical feasibility of sleeve resection in patients with lung cancer. CONCLUSIONS: Arteriographic findings may accurately show whether a sleeve lobectomy is technically possible, that only a pneumonectomy is possible, or that the only safe way to ensure clearance of the pulmonary artery is to perform arterioplasty. This information may obviate an unnecessary thoracotomy in patients who are judged on the basis of a physiologic assessment to be unable to tolerate a pneumonectomy.

Aged↗
PubMed1997

Angiogenesis and dynamic MR imaging gadolinium enhancement of malignant and benign breast lesions.

PURPOSE: To determine whether dynamic magnetic resonance (MR) imaging enhancement parameters are associated with vessel density of malignant and benign breast lesions. MATERIALS AND METHODS: Forty-five patients with 48 breast lesions underwent gadolinium-enhanced spoiled gradient-recalled echo (SPGR) MR imaging followed by excisional biopsy and Factor VIII staining and vessel density measurement in the lesions. RESULTS: The vessel densities were not significantly different in 25 malignant breast lesions as compared to 23 benign breast lesions. Among all 48 lesions, greater MR enhancement showed an association with increased vessel density. Seventy-four percent of all lesions with MRI enhancement amplitude greater or equal to three times post-precontrast ratio had vessel densities greater than the median of 172 as compared to 34% of lesions with enhancement amplitude less than three times, p = 0.02. The rate and washout of MR enhancement showed no significant association with vessel density. CONCLUSION: Although there is an overall significant association between greater MRI enhancement amplitude and vessel density, MRI gadolinium enhancement of breast lesions is not an accurate predictor of vessel density.

Adult↗
PubMed1997

Comparison of palmtop-computer-assisted brief cognitive-behavioral treatment to cognitive-behavioral treatment for panic disorder.

In the present study, the authors sought to determine whether the efficiency and cost-effectiveness of cognitive-behavioral treatment (CBT) for panic disorder could be improved by adjunctive computer-assisted therapy. Eighteen participants who met Diagnostic and Statistical Manual of Mental Disorders (3rd ed., revised; American Psychiatric Association, 1987) criteria for panic disorder were randomly assigned to a 12-session CBT (CBT 12) condition (D. H. Barlow & M. G. Craske, 1989) or to a 4-session computer-assisted CBT (CBT4-CA) condition. Palmtop computers, with a program developed to incorporate basic principles of CBT, were used by CBT4-CA clients whenever they felt anxious or wanted to practice the therapy techniques and were used by all participants as a momentary assessment tool. CBT4-CA clients carried the computer at all times and continued to use it for 8 weeks after termination of therapy. Analyses of clinically significant changes showed superiority of CBT12 at posttest on some measures; however, there were no differences at follow-up.

Adult↗
PubMed1997

A rapid and simple method for extracting human immunodeficiency virus type 1 RNA from plasma: enhanced sensitivity.

We present here a rapid and simple technique for processing human immunodeficiency virus (HIV)-infected plasma by high-speed centrifugation. HIV type 1 virions are pelleted from up to 1 ml of plasma, gently lysed with a nonionic detergent, and directly amplified. The procedure has few manipulations and requires approximately 1.5 h for the processing of 24 samples. Viral recovery ranges from 80 to 90%, with an analytical sensitivity approaching 20 copies/ml.

HIV Infections↗
PubMed1997

Cathepsin D and dynamic magnetic resonance imaging gadolinium enhancement in malignant and benign breast lesions.

Our purpose was to determine whether the expression of cathepsin D, a proteolytic enzyme implicated in basement membrane degradation, is associated with dynamic magnetic resonance imaging (MRI) enhancement of breast lesions. Forty-five patients with 48 breast lesions underwent gadolinium-enhanced spoiled gradient recalled echo MRI followed by excisional biopsy and cathepsin D staining and semiquantitative measurement in the lesions. There was no significant difference in cathepsin D staining of 25 malignant and 23 benign breast lesions. A significant association was seen between high cathepsin D staining and positive axillary lymph nodes in invasive carcinomas. Nine of nine (100%) node-positive carcinomas had high cathepsin D, as compared to three of seven (43%) node-negative carcinomas (P = 0.02). No significant associations were observed between cathepsin D staining and MRI enhancement amplitude, rate, or washout. Cathepsin D has no effect upon MRI gadolinium enhancement of malignant and benign breast lesions but is associated with positive axillary lymph nodes in invasive carcinomas.

Biopsy↗
PubMed1996

Invasive breast carcinoma: analysis of dynamic magnetic resonance imaging enhancement features and cell proliferative activity determined by DNA S-phase percentage.

BACKGROUND: There is little information regarding associations between magnetic resonance imaging (MRI) enhancement and biologic parameters of breast carcinoma. A prospective study was undertaken to correlate MRI dynamic contrast enhancement features with cell proliferative activity, as determined by DNA S-phase percentage. METHODS: Seventeen patients with invasive breast cancer underwent MRI at 1.5 tesla using a dynamic gadolinium-enhanced spoiled gradient recall echo technique. DNA analysis of samples of the excised lesions was then performed using flow cytometry. RESULTS: Invasive carcinomas with high DNA S-phase percentages (> or = 6.9%, the median value in this study), a measure of increased cell proliferation, were associated with a peripheral MRI enhancement pattern in 4 of 6 (67%) lesions compared with 0 of 11 carcinomas with lower DNA S-phase percentages (< or = 6.9%) (P = 0.006). There was no significant association between a high DNA S-phase percentage and greater MRI enhancement amplitude, rate, or washout. There was no significant association between aneuploid DNA content and any MRI enhancement feature. CONCLUSIONS: Increased cell proliferation in invasive breast carcinoma, as determined by high DNA S-phase percentage, is significantly associated with a peripheral MRI enhancement pattern but unrelated to greater MRI enhancement amplitude, rate, or washout.

Adult↗