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Biomedical subjects

B Hoffman

Publications and source records attributed to B Hoffman.

At least 91 records · Page 5Linked to original sources
PubMed1992

Analysis of effects of ultraviolet B radiation on induction of primary allergic reactions.

Acute, low-dose exposure to UVB light reveals a genetic polymorphism in humans with respect to the ability of irradiated skin to support the induction of contact hypersensitivity (CH) to dinitrochlorobenzene (DNCB). In healthy adult caucasians, as well as in humans with deeply pigmented skin, approximately 45% fail to develop CH when DNCB is painted on UVB-irradiated skin; these individuals are termed "UVB susceptible" (UVB-S), whereas those who develop CH at the challenge site are termed "UVB resistant" (UVB-R). The UVB-S trait is characteristic of virtually all patients with biopsy-proved basal/squamous cell cancer, and may therefore be a risk factor for this disease. We have investigated the effects of UVB on expression of primary allergic reactions (PAR) in healthy caucasian and black-skinned adults, as well as patients with skin cancer. Among UVB-R caucasians, very few (less than 25%) developed PAR at site exposed to UVB, whereas among black-skinned UVB-R subjects, all displayed a PAR at the UVB irradiated site. To determine whether the lack of PAR in UVB-R caucasian subjects was systemic or local in origin, DNCB was applied to UVB-exposed buttock skin, and each individual was then challenged with dilute DNCB on forearm skin twice: 11 and 30 d thereafter. When inflammatory responses were evaluated at the original hapten application site, as well as both challenge sites, complete concordance was observed between positive challenge reactions at 30 d (UVB-R) and positive challenge reactions at 11 d, whereas only one caucasian subject displayed a PAR at 12 d. Thus, UVB-R caucasians can display CH as early as 11 d following hapten application to UVB-treated skin, indicating that their failure to display PAR is a local, rather than a systemic, effect of UVB. Because UVB-induced phototoxicity was significantly greater in caucasian than in deeply pigmented skin, it is anticipated that phototoxicity leads to rapid hapten "washout" from UVB-exposed caucasian skin. We propose that PAR usually do not occur in UVB-treated caucasian skin because insufficient hapten remains at the site to trigger a spontaneous inflammation when systemic hapten-specific immunity emerges.

Adult↗
PubMed1992

Evidence for intracellular down-regulation of the epidermal growth factor (EGF) receptor during adenovirus infection by an EGF-independent mechanism.

We have reported previously that human group C adenoviruses down-regulate the epidermal growth factor (EGF) receptor (EGF-R) (C. R. Carlin, A. E. Tollefson, H. A. Brady, B. L. Hoffman, and W. S. M. Wold, Cell 57:135-144, 1989). Expression of a 13.7-kDa protein encoded by a gene in the E3 transcription unit is necessary and sufficient for this effect (Carlin et al., Cell, 1989; B. L. Hoffman, A. Ullrich, W. S. M. Wold, and C. R. Carlin, Mol. Cell. Biol. 10:5521-5524, 1990). We show here that EGF-R down-regulation is accelerated in cells which overexpress the receptor when these cells are infected with virus mutants that overproduce the 13.7-kDa protein compared with wild-type virus. This is in contrast to EGF stimulation, for which others have shown that high concentrations of ligand are associated with low rates of receptor internalization in EGF-R-overexpressing cells (D. Kuppuswamy and L. J. Pike, J. Biol. Chem. 264:3357-3363, 1989; H. S. Wiley, J. Cell Biol. 107:801-810, 1988). We also show that the E3 protein is not present in media conditioned by infected cells and that it does not induce secretion of an EGF-like autocrine factor. Moreover, while mature membrane-bound EGF-R is down-regulated, the precursor of the membrane-bound form is not. Adenovirus infection also does not affect receptor-related molecules expressed in the secretory pathway. Interestingly, adenovirus-induced down-regulation is not regulated by concentrations of EGF associated with a slow rate of internalization in A431 cells. This suggests that 13.7-kDa protein expression triggers receptor entry by a novel ligand-independent pathway or, alternatively, that it compensates for a cellular factor that may be rate limiting during EGF-mediated endocytosis.

Adenoviruses, Human↗
PubMed1991

Comparison of the effects of atenolol and nifedipine on glucose, insulin, and lipid metabolism in patients with hypertension.

Various aspects of carbohydrate and lipid metabolism have been studied in two groups of patients with mild hypertension before and after four months of treatment with either nifedipine (n = 12) or atenolol (n = 12). Mean (+/- SEM) blood pressure fell to the same degree following treatment with either nifedipine (147 +/- 3/98 +/- 2 to 134 +/- 2/85 +/- 2 mm Hg) or atenolol (149 +/- 3/99 +/- 2 to 135 +/- 2/86 +/- 3 mm Hg). Circulating plasma glucose, insulin, and triglyceride concentrations were measured at hourly intervals from 8:00 AM to 4:00 PM, before and after breakfast (8:00 AM), and at lunch time (noon). The response to treatment was different in the two groups. Specifically, plasma glucose concentration were unchanged and insulin concentrations were higher in association with atenolol treatment. In contrast, nifedipine-treated patients had similar plasma insulin, but lower plasma glucose and triglyceride concentrations after four months of therapy. The changes in day-long plasma glucose and insulin responses suggested that resistance to insulin-stimulated glucose uptake had increased in association with atenolol treatment and decreased following nifedipine. This conclusion was supported in that measurement of insulin-stimulated glucose disposal showed a decrease in atenolol-treated patients and an increase in nifedipine-treated patients. Finally, plasma lipoprotein cholesterol concentrations did not change following atenolol therapy, whereas plasma high density lipoprotein cholesterol increased in association with nifedipine administration. These data show that changes in carbohydrate and lipid metabolism observed with treatment of mild hypertension can vary significantly as a function of the drug used, despite similar beneficial effects on blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Atenolol↗
PubMed1991

Employment discrimination: another hurdle for cancer survivors.

Approximately 25% of the six million persons in the United States with a cancer history experience disparate treatment in employment solely because of their medical histories. Many employers do not realize that more than half of the people diagnosed with cancer in 1991 in the United States will overcome their illness, that cancer is not contagious, and that cancer survivors have relatively the same productivity rates as other workers. Decisions to deny employment opportunities to a cancer survivor that are based on misconceptions about cancer, instead of the individual's ability to perform the job, may violate the survivor's legal rights. Employment discrimination against individuals who are qualified for jobs, but are treated differently solely because of their cancer histories, violates most federal and state laws that prohibit employment discrimination based on actual or perceived disabilities. Health professionals, as well as survivors themselves, must take action on three fronts to combat cancer-based discrimination: public and professional education, individual and group advocacy, and appropriate use of legal remedies.

Attitude to Health↗
PubMed1990

Teaching physicians about teaching: an experiential workshop.

Teaching improvement workshops are most effective when they engage teachers actively in practice teaching, particularly when the teaching situation is similar to the actual one to which the teachers will return. Teachers, however, often find such involvement threatening. In this paper we describe a 3 h workshop which succeeds in overcoming teachers' reluctance to participate in situations that are relevant to their real teaching problems, students, and subject matter. The most exciting outcome, in our view, was teachers' increased sensitivity to the limitations of their teaching approach and their increased awareness of the role of their concept of teaching in shaping their teaching strategies. Weaknesses of the workshop include its dependence on the skills of a group director, the tendency of the group to seek a single right answer instead of exploring alternatives and the usual danger of role rigidity which troubles all role enactment procedures.

Ontario↗
PubMed1989

Surviving adult cancers. Part 2: Psychosocial implications.

PURPOSE: To address the psychosocial implications of surviving adult cancers by a comprehensive review of the literature. DATA IDENTIFICATION: An English-language literature search using MEDLINE (1970 to 1988). Index Medicus (1970 to 1988), and bibliographic reviews of textbooks and review articles. STUDY SELECTION: Of 103 originally identified articles, 58 that specifically addressed the stated purpose were selected. DATA EXTRACTION: Four authors reviewed and critiqued the literature extrapolating the major themes on this topic. RESULTS OF DATA SYNTHESIS: There is little information on the many psychosocial variables that affect an adult's long-term cancer survival trajectory. Collation of data identified the following significant psychosocial themes: fear of recurrence and death, relationships with the health care team, adjustment to physical compromise, alterations in customary social support, isolationism, psychosocial reorientation, and employment and insurance problems. CONCLUSIONS: The continuation of a rehabilitation effort begun around the initial diagnosis of cancer would be instrumental in providing post-therapy evaluation and guidance needed by adult long-term survivors of cancer. Education, research, and support interventions need to be mobilized for this population of adults with a history of cancer.

Adaptation, Psychological↗
PubMed1989

Surviving adult cancers. Part 1: Physiologic effects.

PURPOSE: To provide an overview of the physiologic long-term and late effects of adult cancers and cancer treatments by a review of the medical and nursing literature. DATA IDENTIFICATION: Primarily from an English-language literature search using MEDLINE (1980 to 1988) and Index Medicus (1980 to 1988). STUDY SELECTION: After a consensus review by four observers, 285 articles were selected that addressed the stated purpose. DATA EXTRACTION: Four observers assessed the literature using predetermined criteria for eliciting information about long-term and late effects. RESULTS AND DATA SYNTHESIS: Much has been written about the acute phases of cancer and cancer treatments. In comparison, relatively few data are available that define physiologic long-term: and late effects of cancer treatments in adult survivors. Review of the existing data showed that these sequelae may affect virtually any body system months or years after treatment ends. In addition, few prospective studies dealing with physiologic survivorship issues have been done. CONCLUSIONS: Health care providers need to be aware of long-term or late complications that may affect the increasing number of adult cancer survivors. Attention to treatment regimens in the acute cancer phase and careful follow-up once the disease is eradicated may help to prevent or manage these complications. More prospective research should be done in this area.

Adult↗
PubMed1989

Coexistence of Dandy-Walker syndrome and Down's syndrome.

A newborn with Dandy-Walker syndrome was found to have a trisomy 21 karyotype. This is the first reported case of coexisting Dandy-Walker and Down's syndromes. The pathogenetic alternatives for the development of Dandy-Walker syndrome and the implications of the case are discussed.

Cerebrospinal Fluid Shunts↗
PubMed1989

Employment discrimination against cancer survivors: multidisciplinary interventions.

Approximately 25% of the five million cancer survivors in the United States encounter barriers to employment solely because of their cancer histories. This discrimination is primarily rooted in erroneous stereotypes about cancer. Because cancer-based employment discrimination has legal, social, emotional, and economic impact on survivors, interventions must encompass legal and psychosocial resources. While state and federal laws prohibit certain actions that deprive survivors of job opportunities and health insurance, legal and psychosocial resources must be developed and made available to cancer survivors to help them overcome barriers to equal employment opportunities.

Civil Rights↗
PubMed1989

Current issues of cancer survivorship.

"We've cured you, what more could you want?" This query is sometimes posed to cancer survivors by those health professionals who view cancer exclusively as a medical problem. Although this perspective may be the natural consequence of modern medical training, the very training necessary to build upon significant gains in the prevention and treatment of cancer, the clinician's view of the "patient" is often too restricted to recognize the holistic impact of cancer. This article will focus on the medical/physical, psychosocial, and economic/legal issues of concern to cancer survivors.

Adaptation, Psychological↗
PubMed1988

Unexplained neonatal jaundice as an early diagnostic sign of septicemia in the newborn.

This prospective study was performed to determine the frequency of unexplained unconjugated hyperbilirubinemia associated with bacterial infection during the first week of life. Of 5805 infants delivered between September 1984 and December 1986, 93 jaundiced newborns without evidence of septicemia fulfilled the following criteria to be enrolled in the study: weight greater than 2500 g, gestational age greater than 38 weeks, age less than 7 days, and unexplained unconjugated bilirubin greater than 170 mumol/L (greater than 10 mg/dL) during the first 48 hours of life and/or greater than 255 mumol/L (greater than 15 mg/dL) thereafter. Evaluation for septicemia included blood and urine cultures, and white cell and thrombocyte counts. The study disclosed three (3.2%) infants who developed septicemia before any clinical suspicion had been aroused. It is concluded that bacterial infections should be considered a possible cause of neonatal unconjugated hyperbilirubinemia during the first week of life, regardless of the clinical condition of the infant.

Female↗
PubMed1987

Prolonged bradycardia and hypotension after neostigmine administration in a patient receiving atenolol.

A 78-year-old woman admitted for an elective hip operation was maintained on atenolol for control of her hypertension. She received neostigmine and atropine for reversal of muscle relaxation at the end of general anaesthesia. She then developed prolonged bradycardia and hypotension which necessitated the use of adrenaline and isoprenaline. Such an adverse reaction with atenolol has not been described previously.

Aged↗