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Biomedical subjects

B D Weiss

Publications and source records attributed to B D Weiss.

At least 37 records · Page 2Linked to original sources
PubMed1994

Isolation and characterization of a generalized transducing phage for Xanthomonas campestris pv. campestris.

We have isolated and characterized a lytic double-stranded DNA Xanthomonas campestris pv. campestris bacteriophage (XTP1) capable of mediating generalized transduction. The phage transduces chromosomal markers at frequencies of 10(-5) to 10(-6) transductants per PFU. We demonstrated its genetic utility by the isolation and cotransduction of linked transposon insertions to a nonselectable locus, xgl, required for the cleavage of 5-bromo-3-chloro-indoyl-beta-D-galactoside and showed that rif and str alleles in X. campestris are 75% linked. One-step growth experiments showed that the latent and rise periods were each 2 h and the average burst size was 35. The DNA genome is approximately 180 kb, presumably modified in a sequence-specific manner, and may be covalently attached to protein(s). Electron micrographs show the phage particle to have an icosahedral head and contractile tail with tail fibers uniquely attached to a location 40 nm proximal from the end of the tail.

Bacteriophages↗
PubMed1994

Illiteracy among Medicaid recipients and its relationship to health care costs.

Poor literacy is associated with poor health status, but whether illiteracy is also linked to higher medical care costs is unclear. We characterized the literacy skills of 402 randomly selected adult Medicaid enrollees to determine if there was an association between literacy skills and health care costs. Each subject's literacy skills were measured with a bilingual (English/Spanish) reading-assessment instrument. We also reviewed each subject's health care costs over the same one-year period. The mean reading level of this Medicaid population was at grade 5.6. Mean annual health care costs were $4,574 per person. There was no significant relationship between literacy and health care costs. While there are compelling reasons to improve poor reading skills among Medicaid enrollees, illiteracy in this population does not appear to contribute to the high cost of providing government-sponsored care.

Adolescent↗
PubMed1994

Clinical syndromes associated with bicycle seats.

Symptoms related to the bicycle seat are common among cyclists. Skin problems, such as chafing, ischial tuberosity pain, folliculitis, and ulceration are particularly common. Although rarely serious, these problems may cause significant discomfort and interfere with a cyclist's ability to ride. Numerous preventive measures have been recommended to prevent these problems, mostly related to seat position, seat construction, and bicycling pants. Little research is available, however, to support any of these recommendations. Research does indicate that use of skin creams is not effective for prevention of bicycle-related skin problems.

Bicycling↗
PubMed1994

Bicycle-related head injuries.

Bicycle-related head injuries are an important cause of injury and death in the United States, especially among children. There is evidence that widespread use of protective bicycle helmets could markedly decrease the rate of serious head trauma among injured bicyclists, but most cyclists do not wear helmets. Efforts to increase the rate of helmet use have been undertaken in physicians' offices, schools, community-wide programs, and through legislative initiatives. Although some of these interventions have increased helmet use, none has been shown to result in helmet use by the majority of bicyclists.

Bicycling↗
PubMed1993

RU 486. The progesterone antagonist.

The objective of this report is to review the current and potential therapeutic uses of the progesterone antagonist drug RU 486 (mifepristone). Publications cited in peer-reviewed journals were identified through a search of the Index Medicus from 1987 through 1992. A wide range of research reports was reviewed, including human, animal, and tissue culture experiments. Data from published reports were included in this report if they addressed the mechanism of action, clinical indications, and potential uses for RU 486. The review disclosed that as a progesterone antagonist, RU 486 is clinically effective for inducing first-trimester abortions, for ripening and dilating the cervix to facilitate intrauterine surgical procedures, and as a postcoital contragestational agent. As a glucocorticoid antagonist, RU 486 is useful for treating inoperable cases of nonpituitary Cushing's syndrome. RU 486 is under investigation for use as an antineoplastic agent; it has shown promise as a treatment of meningioma, breast cancer, prostate cancer, and hepatoma. RU 486 may also have a role in the treatment of endocrinologic conditions such as endometriosis and premenstrual syndrome. I conclude that RU 486 is effective and in current clinical use for a number of reproductive indications and for treatment of Cushing's syndrome. The drug also has potential as therapy for certain neoplasms and endocrinologic conditions.

Abortion, Induced↗
PubMed1992

Inhibition of tumor implantation at sites of trauma by Arg-Gly-Asp containing proteins and peptides.

We report on the inhibition of wound implantation by TA3Ha mammary carcinoma cells by Arg-Gly-Asp containing proteins and peptides using a hepatic wedge resection model. Intravenously injected TA3Ha cells rarely form tumor in the liver of syngeneic mice, but after hepatic wedge resection, 45% (107/240) of the mice develop tumors in the hepatic wound. Hepatic wound implantation is significantly (P = 0.01) inhibited by pretreating the cells with whole mouse plasma, but not with fibrinogen-depleted plasma or serum. Tumor inhibition is also achieved by pretreatment of cells with fibrinogen (P = 0.05-0.0004), fibronectin (P = 0.007) and laminin, but not by albumin. The active domain appears to be the RGDS sequence since the deca- and tetrapeptides containing RGDS inhibit wound implantation (P less than 0.05). However, the tetrapeptide Arg-Gly-Glu-Ser has no such activity. None of these agents affects ascites tumor formation by the intraperitoneally injected cells, suggesting that anchorage independent growth of cells is not affected. We propose that proteins and peptides containing RGD occupy the binding sites and prevent the cells from interacting with cell adhesion proteins in healing wounds. Proteins and/or peptides containing RGD may be useful for preventing local recurrence in postsurgical cancer patients.

Animals↗
PubMed1992

Trends in bicycle helmet use by children: 1985 to 1990.

Research has demonstrated that helmets protect against head injury during bicycle crashes. Several investigators have shown that large-scale, community-wide programs can increase the rate of helmet use by children. The objective of this research was to determine whether helmet use had changed over a 5-year period in a community with no formal programs designed to increase the use of helmets. In 1985 and again in 1990, project staff observed student bicyclists arriving at four elementary schools, three middle schools, three high schools, and one university campus. The same schools were used both years. There was no significant increase in the percentage of students who used helmets at the middle schools (0 both years), the high schools (1.85% vs 1.45%), or the university (10.0% vs 4.0%). At the four elementary schools, helmet use increased from 1.85% in 1985 to 17.1% in 1990. Much of this increase was attributable to one school at which helmet use increased from 4.4% to 21.4%. This school, and no others, had begun teaching about helmet use in the classroom. The results suggest that (1) helmet use will not increase at the middle school level or higher without specific interventions and (2) simple, low-cost, classroom interventions can increase helmet use by elementary school children.

Adolescent↗
PubMed1991

The relationship between literacy and health.

In non-industrialized countries, populations with the lowest literacy rates have the poorest health status. In the United States, however, there is no published research on whether illiteracy, independently of other sociodemographic factors, is related to health status. There are numerous plausible mechanisms by which such a relationship could occur. For example, published reports indicate that most information handouts, consent forms, and other materials for patients are written at reading levels too difficult for most American adults. These and other findings may have important implications in the health care of underserved populations. Research is needed to determine the health effects of impaired literacy skills among Americans, and to develop non-literacy-dependent methods for providing patient education, obtaining informed consent, and administering diagnostic tests.

Educational Status↗
PubMed1991

Nonpharmacologic treatment of urinary incontinence.

Standard therapy for urinary incontinence often includes pharmaceutical agents that carry a risk of side effects or interactions with other drugs. As an alternative, several nonpharmacologic management approaches are available. Scheduled voiding regimens are effective for patients who have uninhibited detrusor contractions, even when cognitive impairment is present. In motivated patients, pelvic muscle exercise is effective for stress incontinence. These methods are safe and inexpensive, and studies indicate that they can be as effective as or more effective than pharmaceutical agents. Other nonpharmacologic approaches to management include biofeedback techniques and electrical stimulation therapy.

Behavior Therapy↗
PubMed1991

The cervical cap.

The cervical cap is a barrier contraceptive method with an efficacy similar to that of the diaphragm. It has several advantages over other barrier contraceptives. In particular, it can be left in place for up to 48 hours, and repeated applications of spermicide are not necessary, even if sexual intercourse occurs more than once. In addition, the side effects seen with other barrier methods do not occur with the cervical cap. In some women, Papanicolaou tests may become abnormal, especially during the first three months of cap use. Therefore, careful monitoring of cervical cap users is essential.

Contraceptive Devices, Female↗