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Biomedical subjects

B Schwartz

Publications and source records attributed to B Schwartz.

At least 451 records · Page 25Linked to original sources
PubMedDate not supplied

Glaucoma screening in the health care setting.

Glaucoma surveys are an important means of detecting early cases of glaucoma. Traditionally, most such surveys have been conducted in the community, while the health care setting has been underutilized as a screening location. We reviewed studies on surveys conducted in community and health care settings, using tonometry and ophthalmoscopy, and presented data from a study we carried out in the outpatient department of a hospital. Results of our review indicate that over 11 times as many people were screened in the community studies as in the health care studies, but the latter had the higher percentage of referrals. Data from the literature review, as well as from our own study, suggest that the high number of referrals is related to the characteristics of the population available for screening in a health care facility. In such a population there is a higher percentage of individuals at risk for development of glaucoma. Risk factors for the disease include age, sex (males more at risk than females), race, (blacks more at risk than whites), family history of glaucoma, and presence of diabetes and vascular diseases. It was also found that ophthalmoscopy is an effective, but underutilized, method of screening. We recommend an increase in use of health care facilities as sites of glaucoma screening surveys. We also suggest that physicians employ ophthalmoscopy to screen for glaucoma as part of the routine funduscopic examination.

Adult↗
PubMedDate not supplied

Glaucoma screening. A cost-effectiveness analysis.

We designed an intricate model of the process of glaucoma screening, diagnosis, and treatment in order to evaluate the medical care costs of such efforts in relation to the benefits in terms of quality-adjusted years of vision saved, utilizing the economic principles of cost-effectiveness analysis. Although a relatively limited data base and numerous assumptions concerning the accuracy of diagnostic tests, the natural history of ocular hypertension and glaucoma, and the effectiveness of available treatment modalities, limit our ability to draw definitive conclusions concerning the cost-effectiveness of various glaucoma screening options, our analysis indicates that glaucoma screening is probably cost-effective when targeted at certain subgroups of the population. Our analysis suggests that changes in several aspects of existing screening policies may be appropriate if cost-effectiveness is to be used as one of the criteria for the efficient allocation of resources to and within screening programs. Specifically, combinations of screening tests and screening targeted at high risk populations such as blacks, diabetics, and relatives of glaucoma patients are probably more cost-effective than screening of the general population with a single test. In younger populations, the importance of detecting ocular hypertension argues for the use of tonometry. Ophthalmoscopy may be more cost-effective in older age groups in whom the higher prevalence of glaucoma outweighs the need for identifying ocular hypertensives. In the very elderly, automated perimetry becomes cost-effective since the detection of established field loss will have greater yield. In addition, it is evident that diversion of resources away from actual screening efforts and towards efforts aimed at improving follow-up and compliance would be an additional cost-effective strategy.

Adult↗
PubMedDate not supplied

Patients' satisfaction when denied authorization for emergency department care by their managed care plan.

We conducted a survey of managed care plan (MCP) patients who presented to the emergency department (ED) but were denied insurance authorization during a 3-month period. Patients were identified by triage or registration records, contacted by telephone after their visit, and surveyed regarding their satisfaction with the ED and MCP, follow-up care, and future behavior. We surveyed 72 (73.4%) of 98 subjects who were denied authorization. Forty-nine (68.1%) were redirected to a clinic or primary physician, 14 (19.4%) to an urgent care or other ED, and 9 (12.5%) were given no follow-up. Fifty-five respondents (76.4%) stated they had followed-up as directed, but 34 (47.2%) felt the delay had a negative impact. Thirty-nine (54.2%) were dissatisfied with their MCP. If their problems were to recur, 27 (37.5%) stated they would go to a clinic or call their MCP, but 34 (47.2%) would return to the ED. Many patients who are denied authorization are dissatisfied with their MCP and will return to the ED in the future, despite previous denials.

California↗
PubMedDate not supplied

Active surveillance for toxic shock syndrome in the United States, 1986.

Active surveillance for toxic shock syndrome (TSS) was established in 1986 in Los Angeles County and in the states of Missouri, New Jersey, Oklahoma, Tennessee, and Washington. Case reports were solicited through biweekly contact with all acute-care hospitals. One hundred sixteen definite and 63 probable cases were reported; 85% of the cases occurred in female patients and 15% in male patients. Among cases in females, 83 (55%) were menstrual; the mean age of the patients with menstrual cases was 23 years (range, 12-46 years). The overall incidence of TSS was 0.53/100,000. The cumulative incidence varied significantly by region, ranging from 1.23/100,000 in Oklahoma to 0.22/100,000 in New Jersey (P = .0001); the incidence in all other areas ranged from 0.39/100,000 to 0.70/100,000. The incidence of menstrual TSS was 1.05/100,000 women 15-44 years of age and peaked in women between the ages of 15 and 19 years at 1.52/100,000. The incidence was higher in whites than in nonwhites for both menstrual TSS (1.21/100,000 vs. 0.34/100,000, P = .002) and nonmenstrual TSS (0.30/100,000 vs. 0.14/100,000, P = .031). Our data indicate that TSS continues to be a cause of morbidity. Although there is underreporting in national passive surveillance, the proportion of menstrual cases reported through active surveillance was similar to that reported to the passive system in 1986.

Adolescent↗
PubMedDate not supplied

Nonmenstrual toxic shock syndrome associated with barrier contraceptives: report of a case-control study.

Use of barrier contraceptives has been hypothesized to be a risk factor for nonmenstrual toxic shock syndrome (TSS). This association was evaluated in a case-control study of nonmenstrual TSS; cases were identified through an active surveillance system for TSS during 1986 and 1987. Potential risk factors for nonmenstrual TSS were compared for 28 patients and 100 age-matched controls. Use of barrier contraceptives was associated with a significantly increased risk of nonmenstrual TSS, with matched odds ratios of 10.5 and 11.7 for contraceptive sponge and diaphragm use, respectively. Use of nonbarrier contraceptive methods was unrelated to nonmenstrual TSS. Despite the elevated odds ratio, the incidence of nonmenstrual TSS in barrier contraceptives users and the risk of nonmenstrual TSS attributable to barrier contraceptive use are low. Clinicians and women who use barrier contraceptives should be aware of this rare but potentially fatal complication; however, other considerations, such as efficacy and complications associated with other types of contraception, may be more important in the choice of a contraceptive method.

Adolescent↗
PubMedDate not supplied

Chemoprophylaxis for bacterial infections: principles of and application to meningococcal infections.

Chemoprophylaxis with antibiotics is both feasible and desirable for prevention of a potentially serious disease when specific groups at risk can be defined and when a safe, effective, and affordable prophylactic agent is available. Although the Advisory Committee on Immunization Practices recommends rifampin for prophylaxis of meningococcal disease, there are failures of treatment and adverse reactions associated with the administration of this drug, and it cannot be used during pregnancy. In 1987, during an outbreak of group A meningococcal disease in Saudi Arabia, the efficacy of a single intramuscular dose of ceftriaxone was compared with the standard regimen of rifampin for eradication of pharyngeal carriage of Neisseria meningitidis among persons at risk. Follow-up cultures indicated successful eradication for 97% of those who received ceftriaxone and 75% of those who received rifampin. Thus, although ceftriaxone exceeds rifampin in fulfilling the criteria for an effective prophylactic agent, recommendations regarding its use still must be made with caution because of limited clinical experience.

Carrier State↗
PubMedDate not supplied

Calculated neutron dose rates and flux densities from implantable californium-252 point and line sources.

The results of neutron-transport flux-density and dose rate calculations for implantable Californium-252 point and line sources in essentially infinite tissue-equivalent material are presented. The point-source flux densities were obtained from a discrete ordinates calculation, and the point dose rates were established by multiplying the flux densities by their appropriate kerma factors. Line-source dose rates were evaluated by integrating the point dose rates over the length of the line source. Dose-rate data are given within a 20 X 20-cm region from the source center for source lengths of 1.5, 2, and 3 cm. The dose rates established by these calculations showed good agreement with an independent Monte Carlo calculation. Detailed point-source flux-density data as a function of energy and position are also given.

Californium↗
PubMedDate not supplied

Mecillinam activity compared to ampicillin, trimethoprim/sulfamethoxazole, ciprofloxacin and nitrofurantoin against urinary tract isolates of gram-negative bacilli.

Recent Canadian, American and European studies have reported increased ampicillin and trimethoprim/sulfamethoxazole resistance among urinary tract isolates of Escherichia coli. This trend suggests that a reevaluation of first- and second-line therapies for the treatment of community-acquired urinary tract infections is necessary. Mecillinam, a beta-lactam with preferential activity against gram-negative penicillin binding protein 2 (unlike other beta-lactams which preferentially bind gram-negative penicillin binding proteins 1a, 1b or 3), may offer clinically significant activity against ampicillin-resistant and trimethoprim/sulfamethoxazole-resistant E. coli. To test this assertion, the activity of mecillinam was compared with ampicillin, trimethoprim/sulfamethoxazole, nitrofurantoin and ciprofloxacin against 258 consecutive gram-negative urinary tract isolates collected at a Canadian tertiary care hospital. Mecillinam demonstrated significantly better activity than ampicillin and trimethoprim/sulfamethoxazole and significantly less activity than ciprofloxacin and nitrofurantoin against the 258 isolates tested. Against E. coli isolates specifically, mecillinam was significantly more active than ampicillin and trimethoprim/sulfamethoxazole (p < 0. 001) and as active as ciprofloxacin and nitrofurantoin. Mecillinam was active against 91.9% of ampicillin-resistant E. coli and 95.9% of trimethoprim/sulfamethoxazole-resistant E. coli. We conclude that mecillinam should be reevaluated for potential use in the treatment of community-acquired urinary tract infections.

Amdinocillin↗
PubMedDate not supplied

Evaluation of the circulation in the retina, peripapillary choroid and optic disk in normal-tension glaucoma.

Computerized image analysis, including fluorescein angiography, was used to evaluate the retinal, choroidal and optic disk blood flow in 16 patients with normal-tension glaucoma (NTG) and to correlate this measurement with visual fields, retinal vessel width, optic disk pallor and blood pressure (BP). The angle of the ascending slope of the fluorescein dye curve was measured as an index of blood flow from the densitometric and time curves of the fluorescein angiograms in the optic disk, peripapillary choroid, retinal artery and vein for each quadrant. While the ascending slope as well as the retinal vessel width were most reduced in the inferior and nasal regions, the mean threshold was lowest in the superior and nasal quadrants. There were positive significant correlations between artery width and threshold value, between angles of slopes and pallor. In addition, systolic BP had a negative correlation with pallor, and diastolic BP had a positive one with slope in the choroid. These results indicated the probable association of a decrease in retinal, choroidal and optic disk blood flow in the inferior and nasal quadrants as well as vessel width in the inferior nasal quadrant with visual field loss in the superior quadrant, and also demonstrated an increasing blood flow for enlargement of pallor. A decrease in BP was found to be related to reduced blood flow in choroid and optic disk impairment.

Blood Circulation↗
PubMedDate not supplied

Utility of the in situ detection of HPV in Pap smears diagnosed as within normal limits.

OBJECTIVE: To determine the clinical significance in normal Pap smears of HPV detection as determined by Hybrid Capture (HC) and in situ hybridization analyses. STUDY DESIGN: We studied 135 consecutive Pap smears as well as 46 other smears from high-risk patients each initially diagnosed as within normal limits. RESULTS: The 135 "normal" Pap smears were rescreened, and 6 (4%) where found to be either ASCUS or SIL. In the remaining 129 cases, HPV DNA was detected in 0% and 9%, respectively, using in situ hybridization and HC I. Upon rescreening the high-risk patients, nine (20%) were reclassified as having SIL/ASCUS; each was in situ hybridization positive, and eight were HC positive; six (67%) of these women developed SIL on follow-up. In the 37 Pap smears in high-risk women still within normal limits after manual rescreening, HPV was detected in 2% by in situ hybridization and 46% by HC; 6% of the HC-positive women developed SIL on follow-up. CONCLUSION: In situ hybridization rarely detects HPV in Pap smears diagnosed as within normal limits after manual rescreening. In situ hybridization is very effective in detecting rare, atypical cells in Pap smears diagnosed as within normal limits and, in a high-risk population, is predictive of SIL on clinical follow-up.

Adolescent↗
PubMedDate not supplied

emm typing and validation of provisional M types for group A streptococci.

This report discusses the following issues related to typing of group A streptococci (GAS): The development and use of the 5' emm variable region sequencing (emm typing) in relation to the existing serologic typing system; the designation of emm types in relation to M types; a system for validation of new emm types; criteria for validation of provisional M types to new M-types; a list of reference type cultures for each of the M-type or emm-type strains of GAS; the results of the first culture exchange program for a quality control testing system among the national and World Health Organization collaborating centers for streptococci; and dissemination of new approaches to typing of GAS to the international streptococcal community.

Antigens, Bacterial↗
PubMedDate not supplied

Improving community support for HIV and AIDS prevention through national partnerships.

If the transmission of human immunodeficiency virus (HIV) is to be prevented, the environment in which people live should predispose them to engage in and sustain safe behaviors. Too often in public health, the range of organizations that make up that environment are overlooked, and prevention strategies are limited to familiar medical and public health institutions. Improvement in public health does not occur in isolation, apart from the other institutions of society--and so it is with the HIV-AIDS epidemic. Education; business and labor; religion; government; voluntary, civic, and social organizations; and the media can all serve as facilitators or as barriers to creating the environment--at the national, regional, State, or local level--that will prevent and control the spread of HIV infection and AIDS and support the needs of those already infected. Collectively, they become a comprehensive HIV prevention network with access to and influence on the total public. One of the most significant benefits of this network is the multiplier effect on the limited resources of public health. Therefore, as part of its HIV and AIDS prevention strategy, the Centers for Disease Control (CDC) has developed national partnerships to involve the leadership of business, labor and industry, religious institutions and organizations, and voluntary organizations in HIV and AIDS prevention and service. Some of these partnerships are federally funded, others are not. The national partnership program described in this paper has produced increased resources for HIV education and services and has demonstrated the synergistic benefits resulting from public and private cooperation in addressing the HIV epidemic.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Characterization of tyrosine protein kinase associated with subcellular components of human colonic epithelium.

Tyrosine protein kinase (TPK) co-isolated with subcellular components derived from human colonic epithelium. The highest TPK activity, measured in the Triton X-100-insoluble cytoskeletal pellet, was directly related to the degree of malignancy of colonic tissue. TPK activity was assayed by measuring the incorporation of [gamma-32P] from [gamma-32]ATP into the synthetic polymer [Glu80Tyr20]n substrate. Lineweaver-Burk plots yielded an apparent Km of 167 micrograms/ml for [Glu80Tyr20]n and of 19 microM for ATP: Vmax for the phosphate donor was 0.9 nmol/min/mg protein. TPK activity was markedly stimulated by the metal ions Mg2+ and Mn2+ and significantly suppressed by tyrphostins, potent specific TPK inhibitors, shown to interfere with TPK-dependent growth processes. This is first report to present evidence for TPK activity associated with cytoskeleton-enriched subcellular preparations harvested from human colonic epithelium.

Benzylidene Compounds↗
PubMedDate not supplied

Growth-related enzyme activities in crypt compartments during rat colon carcinogenesis.

The activities of the growth-related enzymes ornithine decarboxylase (ODC) and casein kinase II (CK-II) were assayed along the colon crypt axis in a precise temporal sequence following administration of 1,2-dimethylhydrazine (DMH) to male rats. The time course of events monitored in colonic cell populations sequentially harvested by a scraping procedure shows that the potent carcinogenic insult induces an early and late ODC activity peak: the distinct biphasic response of the decarboxylase was observed in all colonic crypt compartments. The activity gradient of CK-II was markedly altered in DMH-treated cell populations: brisk activity of the kinase was observed in the upper crypt zone, the preserve of the mature, non-dividing colonocyte. The enhanced responses of ODC and of CK-II to DMH proceeded the actual polyp and tumor formation. The polycations spermine and spermidine, bioactive molecules formed in the ODC-controlled polyamine pathway, were shown to markedly activate colonic CK-II. This observation suggests that ODC and CK-II, enzymes with different catalytic purposes, crosstalk within the colonic crypt continuum. The present findings indicate that the differentiation arrest of colonic cells and their misplacement in forbidden zones of the crypt axis during DMH-induced carcinogenesis is accompanied by early alterations in the activity and topology of disparate enzymes which are part of the orderly growth program of the normal colonic cell.

1,2-Dimethylhydrazine↗
PubMedDate not supplied

Construction of a modified murine interferon alpha with increased stability.

The mutant [Ser86] murine interferon alpha A was constructed by oligodeoxyribonucleotide-directed site-specific mutagenesis and expressed under the control of lambda phage PL promoter in Escherichia coli. The effect of the substitution of serine for the cysteine residue at position 86 in the murine interferon alpha A was studied. It was observed that the mutant Ser86 murine interferon alpha A which does not contain the free cysteine residue in the peptide was inactivated more slowly than its parent with a free cysteine residue at position 86. Heat-inactivated murine interferon alpha A cannot be reactivated, but the heat-inactivated Ser86 derivative can be reactivated significantly to about 27.5 per cent of the original activity in the presence of sodium dodecylsulfate. These results suggest that the free cysteine in the peptide is a factor contributing to the instability of the protein.

Bacteriophage lambda↗