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Biomedical subjects

L W Roberts

Publications and source records attributed to L W Roberts.

At least 55 records · Page 3Linked to original sources
PubMed1978

Stylostome formation by Leptotrombidium mites (Acari: Trombiculidae).

The modes of stylostome formation by larvae (chiggers) of Leptotrombidium intermedium, L. fletcheri, L. arenicola, and L. deliense in parasitized mouse skin were studied histologically in relation to their capacity to transmit Rickettsia tsutsugamushi. Three types of stylostome formation were recognized among the different species: the epidermal stylostome formed by the larva of L. intermedium; the mesenchymal stylostome formed by the larva of L. fletcheri; and, the mixed stylostome formed by the larva of both L. arenicola and L. deliense. Dermal inflammations related to the three types of stylostomes were histologically defined. The possible importance of stylostome characteristics to the transmission of rickettsial organisms is discussed.

Animals↗
PubMed1977

Pharmacy-assisted burn unit skin bank program.

Assistance by pharmacy services in the development and production of a sterile fluid for the preservation of homograft skin after "harvesting" from cadavers is described. Discussion includes the need for skin banking; sterile skin bank fluid formulation, production, storage use; physiological effects of homograft skin; indications for homograft usage; and acceptable cadaver donors.

Burns↗
PubMed1977

Numbers of Leptotrombidium (Leptotrombidium) deliense (Acarina: trombiculidae) and prevalence of Rickettsia tsutsugamushi in adjacent habitats of peninsular Malaysia.

Numbers of L. (L.) deliense larvae were determined in adjacent habitats over a 16 month period. Both R. argentiventer and R. tiomanicus were highly efficient hosts for L. (L.) deliense. R. argentiventer was host to significantly greater numbers of chiggers per rat than was R. tiomanicus. The 2 habitats were similar in numbers of chiggers collected. No consistent correlation was apparent between numbers of chiggers and any single weather factor, but the chigger population seemed to be adversely affected by a 2 month period during which total evaporation greatly exceeded total rainfall. Direct fluorescent antibody examination of tissues from unfed L. (L.) deliense showed that 2 of 420 larvae (0.5%) contained organisms morphologically resembling R. tsutsugamushi. Considering the vector load and numbers of chiggers being returned to the ground by a given host, a rate of 0.5% appeared adequate to account for the prevalence rate of R. tsutsugamushi observed in the 2 host species.

Animals↗
PubMed1977

Virulence and antigenic properties of Rickettsia tsutsugamushi in a naturally infectei laboratory colony of Leptotrombidium (leptotrombidium) arenicola.

Over 1,200 isolations of R. tsutsugamushi were obtained over 7 generations of L. (L.) arenicola and no reproducible differences in virulence or antigenic markers could be detected among these isolations. The F8 generation yielded rickettsia with the same antigenic makeup and virulence properties as the original female parent mite. When these isolates were inoculated into mice they elicited the same predominant antibody specificities, i.e. they all produced antibody which reacted with the TA 763 and Karp strains. These were the same as the major antigens detected by direct fluorescent antibody staining of the isolates.

Animals↗
PubMed1976

The effect of amitrole (3-amino-1H-1,2-4-triazole) on cytokinin activity and sexual reproduction in the yeast Schizosaccharomyces octosporus.

Cytokinin activity in extracts from actively growing cultures of Schizosaccharomyces octosporus was greatly reduced by exposure to amitrole (5 X 10--3M). Amitrole treatment, at the same concentration, stimulated cell enlargment and ascus production in this organism. These data suggest that a relationship may exist between low levels of endogenous cytokinins, cell expansion in preference to cell division, and ascus formation.

Amitrole↗
PubMed1976

Pharmacy-based special infant formula service.

The preparation of infant formulas by a hospital pharmacy for a 280-bed department of pediatrics is discussed. A formulary of acceptable special therapeutic formulas was developed in conjunction with the pediatricians. Space and equipment originally intended for intravenous admixture and total parenteral nutrition services were supplemented to include special infant formula services. The personnel and equipment requirements, and quality control procedures, of the service are discussed.

Formularies, Hospital as Topic↗
PubMedDate not supplied

The ethical basis of psychiatric research: conceptual issues and empirical findings.

The study objective was to clarify the ethical basis of psychiatric research by outlining conceptual issues and empirical findings related to the ethics of human experimentation. A systematic review of scholarly and empirical literature covering three decades was performed. The ethics of human research has come to be understood in relation to the principles of respect for persons, beneficence, justice, and the ideal of informed consent. Subjects who cannot fully participate in informed-consent processes are especially vulnerable to exploitation. Current dilemmas stem from insufficient attention to the vulnerabilities of mentally ill research participants, problems in applying ethical concepts and guidelines to psychiatric research, and claims of research misconduct. Empirical studies indicate that (1) psychiatric symptoms significantly affect informed consent, (2) psychiatric patients may possess certain strengths with respect to research involvement, (3) proxy decision-making is problematic, (4) informed consent is also difficult to attain with the medically ill and others, (5) patients are motivated to participate in research by the hope of personal benefit, (6) ethical aspects of research are poorly documented, and (7) institutional review processes may not be adequate to protect vulnerable subjects. Psychiatric research can be performed ethically, according to standards set throughout the biomedical and behavioral sciences, so long as researchers and institutions are respectful of special ethical issues in human experimentation and strive to include vulnerable study participants fully in research decisions. However, many gaps in the empirical literature exist regarding the specific nature and implementation of ethics principles in psychiatric research. Efforts to advance both science and ethics, including the study of ethical dimensions of human research itself, are essential for the future of psychiatry.

Attitude to Health↗
PubMedDate not supplied

Attitudes of consultation-liaison psychiatrists toward physician-assisted death practices.

The objective of this study was to investigate the views of consultation-liaison (C-L) psychiatrists on assisted-death practices. A 33-question anonymous survey was distributed at the Academy of Psychosomatic Medicine Annual Meeting in November 1995. The instrument explored perceptions of acceptability of assisted death in six hypothetical patient situations as performed by four possible agents. The response rate was 48% (184 conference attendees participated, i.e., completed and returned the surveys). With little variability, the respondents were unwilling to perform assisted death personally and also did not support assisted death as performed by nonphysicians. The respondents were somewhat more accepting of referral or other physicians' involvement in such practices. Assisted death was viewed differently than withdrawal of life support. Several variables were analyzed for their influences on the views expressed. The C-L psychiatrists in this study expressed opposition to assisted death practices. Their views varied somewhat depending on the patient vignette and the agent of death assistance. The authors conclude that C-L psychiatrists may wish to develop their present therapeutic and evaluative role in patient care to alleviate suffering, without hastening patient death.

Adult↗
PubMedDate not supplied

Medical students' evolving perspectives on their personal health care: clinical and educational implications of a longitudinal study.

The mental and physical health care issues of medical students are increasingly recognized as both prevalent and complex. Emotional distress, symptoms of mental illness, and maladaptive substance use are widespread and may often be driven by training-related stressors. The data suggest that nearly all medical students identify physical health concerns as well. The care of medical students as patients is complex because of problems associated with the stigma of various illnesses and the dual role of trainee and patient in medical school. A written confidential survey assessed students longitudinally near the end of their first and third years of training regarding their perceived health care needs, health concerns, attitudes toward care, access to services, and care-seeking practices (161 items). A subset of students (n = 33) were reassessed 1 month after the second survey to measure reliability. McNemar's chi-square (chi2) tests, repeated-measures multivariate analysis of variance (MANOVA), and K and Pearson correlations were used to evaluate outcomes. Almost all students reported health care needs during both training phases, and their mental and physical health concerns were stable over time. However, the preference for obtaining health care at a site other than their training institution and concerns about confidentiality increased, although students were marginally more likely to obtain care at their medical school during clinical versus preclinical training. The students' tendency to seek informal care from colleagues remained consistent, as did their high level of concern about professional jeopardy relating to personal health issues. Their tendency to accept the dual patient-student role depended on the particular health care issue; they expressed a strong tendency to protect other students' confidentiality, even in cases of potential significant impairment. Responses were reliable across a 1-month retest interval. We conclude that medical students' perspectives on their mental and physical health care across the transition from preclinical to clinical training reveal the importance of pursuing, not neglecting, a number of clinical and educational initiatives. Through their specialized expertise, psychiatrists may help to ensure sound mental and physical health care for the more than 69,000 medical students in training in this country.

Adult↗
PubMedDate not supplied

Perceptions of academic vulnerability associated with personal illness: a study of 1,027 students at nine medical schools. Collaborative Research Group on Medical Student Health.

About one quarter of the more than 69,000 medical students in this country suffer symptoms of mental illness, including 7% to 18% with substance use disorders. Subjective distress and physical health needs of medical students are also common and have been linked to training stresses. This first large-scale study of medical student health care examined students' physical and mental health concerns and their perceptions of academic vulnerability associated with personal illness. A 7-page, confidential written survey was given to 1,964 students at nine US medical schools in 1996 and 1997. A total of 1,027 students participated (52% response rate). Nearly all (90%) reported needing care for various health concerns, including 47% having at least one mental health or substance-related health issue. A majority of students expressed a preference for health care outside their training institution, largely due to confidentiality concerns, and 90% preferred health insurance allowing off-site care. Students expressed varying levels of concern about academic jeopardy in association with personal illness, with physical health problems such as arthritis causing the least concern and alcohol and drug abuse triggering the most concern. Consistent differences were detected in these views based on respondent's gender, training level, and institution. Most medical students perceive the need for personal health care. Nevertheless, fear of academic reprisal may prevent medical students from seeking necessary care for their health problems during training. This phenomenon may be linked in important but poorly recognized ways to emerging illness and to impairment among medical students and physicians. Women, minority, and clinical students appear more sensitive to the connection between health and academic vulnerability. Constructive implications for medical school curricula, policies, and health care services are discussed.

Adult↗
PubMedDate not supplied

A framework for considering the ethical aspects of psychiatric research protocols.

The ethics of psychiatric research has emerged as a topic of national importance. Attention to this topic has been stimulated by a number of factors, including heightened awareness of the distinct moral problems arising in the care of mental illness, the rapid development of new psychopharmaceutical agents, the emergence of evidence-based approaches in psychiatry, the expansion of clinical trials within the private mental health sector, and recent recommendations offered by the President's National Bioethics Advisory Commission (NBAC). Consequently, clinical practitioners and investigators alike will increasingly be called upon to evaluate the ethical acceptability of psychiatric research protocols encountered in their professional work. In light of this, we present a framework for considering ethical aspects of psychiatric research protocols. This framework gives emphasis to nine elements: (1) scientific issues; (2) research team issues; (3) risk and benefit in protocol design; (4) confidentiality; (5) selection, exclusion, and recruitment considerations; (6) informed consent and decisional capacity; (7) incentives; (8) institutional and peer/professional review issues; and (9) data presentation issues. Case illustrations are provided. It is hoped that enhanced knowledge of the considerations presented in this framework will ultimately improve our ability to help people with mental illness.

Clinical Trials as Topic↗