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Biomedical subjects

S Ross

Publications and source records attributed to S Ross.

At least 163 records · Page 9Linked to original sources
PubMed1993

Genetic risk factors in diabetic retinopathy.

Diabetic retinopathy is the leading cause of blindness in adults aged 30 to 65 years. However, 20% of the diabetic population does not develop significant retinopathy. To examine the influence of immune-related genetic factors on the development of diabetic retinopathy, we studied immunoglobulin allotypes in 102 subjects aged 8 to 20 years, who had had Type 1 (insulin-dependent) diabetes mellitus for 4.5 to 11 years (mean 7.3 years). HLA had been previously typed on 59 of these subjects. Retinopathy was assessed by expert review of retinal photographs. Among the 44 patients who had evidence of retinopathy, 33(75%) were G2m(23+), while among the 58 patients without retinopathy but with similar duration of disease, only 28(48%) were G2m(23+) (p = 0.006). The HLA-DR types of patients with and without retinopathy were not significantly different. We conclude that there is significant evidence of an association between G2m(23) at the locus encoding IgG2 subclass heavy chains and susceptibility to the development of diabetic retinopathy early in the clinical course of the disease. Our findings provide important independent confirmation of a previous report of association between Gm allotypes and predisposition to diabetic retinopathy. We are unable to determine if the Gm effect on development of retinopathy is due to the G2m(23) allotype itself, or due to genes that are closely linked to, and in linkage disequilibrium with, the locus encoding the G2m(23) allotype.

Adolescent↗
PubMed1993

Empyema due to Bacteroides gracilis: case report and in vitro susceptibilities to eight antimicrobial agents.

We describe a patient with empyema due to Bacteroides gracilis and a viridans streptococcus. Therapy with both cefoxitin and imipenem failed, and the patient remained symptomatic even after thoracotomy was performed. Clinical response occurred after initiation of clindamycin therapy. The susceptibilities of the patient's isolate, other clinical strains, and the reference strain were determined by an agar dilution method. The isolates were generally susceptible to all the agents tested; however, some strains were resistant to clindamycin (MIC, 8 micrograms/mL), penicillin G (MIC90, 16 micrograms/mL), and metronidazole (MIC90, 64 micrograms/mL). The B. gracilis isolate from our patient was susceptible to all agents tested, including cefoxitin and imipenem.

Adult↗
PubMed1993

Adoptive immunotherapy of hormone-refractory, stage D2 prostate cancer using ex vivo activated autologous T cells (autolymphocyte therapy): results from a pilot study.

There is no effective therapy available for stage D2 prostate cancer once patients become refractory to hormonal therapy. In a pilot study, we treated 17 patients with hormone-refractory stage D2 prostate cancer using autolymphocyte therapy, an outpatient form of adoptive immunotherapy in which patients are treated with autologous T cells that have been activated ex vivo. Feasibility and safety were documented. Transient PSA reductions up to 66% were noted, suggesting biological activity. Further studies to test the safety and efficacy of autolymphocyte therapy in the treatment of prostate cancer are warranted.

Aged↗
PubMed1993

Epidemiological study of tinea capitis in Puerto Rico.

Two separate studies were carried out to determine the dermatophytes responsible for tinea capitis in Puerto Rico. A retrospective study to determine those agents during the period between 1979 and 1989 revealed a total of 36 mycologically positive cases. The causative organisms consisted of the following species: M. canis, 14 cases (38.9%); T. mentagrophytes, 7 cases (19.4%); T. rubrum, 7 cases (19.4%); M. gypseum, 5 cases (13.9%); and T. tonsurans, T. verrucosum, unclassified Microsporum species, 1 case each (2.8% each). In a prospective study, fungal cultures were obtained from the scalps of 95 randomly selected children (45 males, 50 females) seen at the outpatient dermatology clinics of the Medical Sciences Campus of the University of Puerto Rico for a variety of skin problems but with no symptoms or signs of disease. One culture was positive for M. canis. All other cultures were negative. The significance of these findings is discussed as well as their relation to the incidence of T. tonsurans scalp infections in the Unites States.

Adolescent↗
PubMed1992

Social effects of wheeze in childhood: a 25 year follow up.

OBJECTIVES: To determine the outcome of childhood wheeze in terms of education, employment, housing, and social class. DESIGN: 25 year follow up study. SETTING: Community study based at the department of thoracic medicine, Aberdeen Royal Infirmary. PARTICIPANTS: Three groups of subjects who had been identified in a random community survey in 1964: those who had had asthma in childhood (n = 97), those who had wheezed only in the presence of upper respiratory tract infections (n = 132), and a comparison group who had had no respiratory symptoms as children (n = 131). Subjects were aged 34 to 40 years at the time of the current study. MAIN OUTCOME MEASURES: Interview and questionnaire data on education, employment, housing and social class, ventilatory function, and peak flow rate. RESULTS: Pulmonary function testing showed that only the "asthmatic" group had airways obstruction; this group showed greater peak flow variation than the "wheezy" group, which did not differ from the comparison group. The asthmatic subjects were more likely to have experienced respiratory problems during their school years and associated with their work. Despite these problems, educational attainment, employment, housing, and eventual social class were similar for all three groups. CONCLUSION: Childhood wheeze did not adversely affect education, employment, housing, or social class in this population.

Asthma↗
PubMed1991

Analysis of the genes involved in the insulin transmembrane mitogenic signal in Chinese hamster ovary cells, CHO-K1, utilizing insulin-independent mutants.

CHO-K1 cells, wild type (WT), grow in a defined medium with insulin as the only essential hormone. When starved for insulin, these cells accumulate in G0/G1 stage. Insulin binding to its receptor stimulates DNA synthesis and cell division and induces an increase in abundance of mRNA for c-fos, c-jun, Krox-20, Krox-24 (zif/268), fra-1, jun-B, c-myc, and JE. The kinetics of induction of these genes are similar to that shown with serum induction of 3T3. These genes show maximum stimulation at insulin concentrations of 20, 160, or 320 ng/ml and their expression is inhibited at higher concentrations. The addition of cycloheximide results in superinduction. The WT and insulin-independent mutants show no detectable signal for KC, fos-b, or nur77 and no increase over the basal level of pI-15, probably eliminating these genes as participants in the insulin mitogenic signal. These mutants synthesize DNA in the absence of insulin at rates that vary from 4 to 12 times that of the quiescent (insulin unstimulated) WT and are further inducible by insulin. The mutants have "constitutive" levels of Krox-24 (zif/268), fra-1, jun-B, c-myc, and JE (INS-type 2 genes) mRNAs that vary from mutant to mutant, reaching a maximum of an 8-fold increase for fra-1 and JE over the quiescent WT levels. There were no detectable levels of mRNA for genes c-fos and Krox-20 and no increase in level of mRNA for c-jun (INS-type 1 genes) as compared to the quiescent WT. Thus, although these INS-type 1 and type 2 genes may be involved in the full insulin mitogenic signal, the constitutive up-regulation of only genes in INS-type 2 is sufficient for insulin-independent DNA synthesis and cell division. Analysis of hybrids constructed between WT and mutant 27 indicate that the mutant phenotype is recessive, pointing to the existence of a regulatory gene producing a negative regulator.

Animals↗
PubMed1991

Medical students' perceptions of children: modifying a childhood cancer stereotype.

To assess whether an educationally based intervention could mitigate the negative effects of a childhood cancer stereotype, 168 first-year and fourth-year medical students were randomly assigned to view a healthy child described with either a healthy label (HL) or an in remission from leukemia label (RLL). One half of the 1st-year students also were given information summarizing the psychosocial sequelae of child survivors of cancer and one half were not given information. MANOVAs revealed that medical students in the information condition did not evidence any biases toward RLL children. However, RLL children were rated more negatively than HL children on several dimensions by 1st- and 4th-year students who did not participate in the intervention. The results suggest that a childhood cancer stereotype can be eliminated; however, standard medical training does not reduce the negative expectations health care providers hold toward children diagnosed with cancer.

Adult↗