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Biomedical subjects

M C Smith

Publications and source records attributed to M C Smith.

At least 91 records · Page 5Linked to original sources

Effect of binge eating on the prediction of weight loss in obese women.

Factors that may be associated with successful weight loss in the obese are of clinical and theoretical significance. Although perceived behavioral control (PBC) had been shown to predict weight loss in a nonclinical population, it had not been used to predict weight loss in the obese. We studied obese women enrolled in a 15-week structured weight loss program and hypothesized that PBC would predict weight loss for low binge eaters better than for high binge eaters. Results indicated that the ability of PBC to predict weight loss immediately posttreatment and 6 months posttreatment depended on binge eating severity, whereas prediction of group attendance was independent of binge eating status.

Adult↗

A preliminary description of nonschool-based friendship in young high-risk children.

This study explored friendships in a sample of 51 high-risk preschool-aged children. Thirty-eight children were placed in foster care (25 placed with their siblings and 13 separated from their siblings). Thirteen children, receiving preventive services, were living at home with their biological parents and siblings. Chi-square, ANOVA, and paired t-tests were used to test for between-group and within-subject differences in the target children's friendships. The results demonstrated that the majority of the high-risk children had a ''best friend." However, the foster children all had friends who could be described as quasi-siblings. The results suggest that foster care placement and the presence of siblings may influence the nature of a child's interactions with nonrelated peers.

Child↗

The effects of angiotensin II receptor blockade with losartan on systemic blood pressure and renal and extrarenal prostaglandin synthesis in women with essential hypertension.

The major antihypertensive effect of losartan, a nonpeptide angiotensin II antagonist, is thought to be due to inhibition of the pressor effects of angiotensin II. It is possible, however, that losartan alters the synthesis of vasodilator or vasoconstrictor prostaglandins (PG), thus contributing to its antihypertensive effect. Sixteen postmenopausal women with essential hypertension, with a mean age of 59 years and diastolic blood pressures of 95 to 115 mm Hg, were enrolled in a 12-week, single-blind study to determine the effects of losartan on blood pressure, renal and extrarenal PG production, plasma renin activity (PRA), plasma aldosterone, and routine biochemical parameters. The subjects received placebo during weeks 1 to 4, 50 mg losartan daily during weeks 5 to 8, and placebo during weeks 9 to 12. During the 4-week treatment period, there were no significant, sustained changes in renal or extrarenal synthesis of PGE2, PGI2, or thromboxane A2. Losartan significantly reduced systolic blood pressure from 155 +/- 11 mm Hg (mean +/- SD) to 139 +/- 13 mm Hg (P = .001) and diastolic blood pressure from 100 +/- 2 mm Hg to 87 +/- 5 mm Hg (P < .001) despite the fact that the majority of patients had low PRA. Plasma aldosterone concentration decreased from 9.7 +/- 6.5 ng/dL to 5.1 +/- 3.9 ng/dL (P = .002) and serum uric acid declined from 4.6 +/- 0.8 mg/dL to 4.2 +/- 0.8 mg/dL (P = .018) after 4 weeks of treatment with losartan. We conclude that 1) losartan decreases blood pressure in women with essential hypertension and low plasma renin activity; 2) the antihypertensive effect is not associated with sustained changes in renal or extrarenal PG production; and 3) losartan reduces plasma aldosterone and serum uric acid concentrations in patients with essential hypertension.

Aged↗

Significance of unilateral ear extinction on the dichotic listening test.

The association between unilateral ear extinction on the dichotic listening test and the lateralization of epileptogenic foci was examined in a sample of 49 seizure patients undergoing preoperative evaluation for epilepsy surgery. Results from patients who were left hemisphere dominant for speech indicated that right ear impairment was always predictive of a unilateral left hemisphere focus, but left ear extinction was associated with unilateral lesions of either hemisphere. In this patient sample, dichotic listening performance reflected an interaction of both lateralized foci and hemispheric preference of language processing. Implications concerning clinical use of the dichotic listening test are discussed.

Adolescent↗

Landau-Kleffner syndrome. Treatment with subpial intracortical transection.

Landau-Kleffner syndrome (LKS) is an acquired epileptic aphasia occurring in childhood and associated with a generally poor prognosis for recovery of speech. It is thought to be the result of an epileptogenic lesion arising in speech cortex during a critical period of development. Utilizing a new surgical technique designed to eliminate the capacity of cortical tissue to generate seizures while preserving the normal cortical physiological function, we have treated 14 children with aphasia, seizures and a severely abnormal EEG by multiple subpial transection of the epileptogenic cortex. Seven of the 14 patients (50%) have recovered age-appropriate speech, are in regular classes in school and no longer require speech therapy. Four of the 14 (29%) have shown marked improvement, are speaking and understanding verbal instruction but are still receiving speech therapy. Thus, 11 of the 14 (79%), none of whom had used language to communicate for at least 2 years, are now speaking--a rate of sustained improvement considered unusual in this disorder. This study documents the value of a treatment modality not previously used in LKS. Success depends on selection of cases having severe epileptogenic abnormality that can be demonstrated to be unilateral in origin despite a bilateral electrographic manifestation.

Adolescent↗

Control of lytic development in the Streptomyces temperate phage phi C31.

The repressor gene, c, is required for maintenance of lysogeny in the Streptomyces phage phi C31. The c gene expresses three in-frame N-terminally different protein isoforms at least one of which is thought to bind to a 17bp highly conserved inverted repeat (CIR) sequence found at 18 (or more) loci throughout the phi C31 genome. Here we present evidence that one of these loci, CIR6, and its interaction with the products of the repressor gene are critical in the control of the lytic pathway in phi C31. To the right of CIR6, according to the standard map of phi C31, an 'immediate-early' promoter, ap1, was discovered after insertion of a fragment containing CIR6 upstream of a promoterless kanamycin-resistance gene, aphII, to form pCIA2. pCIA2 conferred kanamycin resistance upon Streptomyces coelicolor A3(2) but not upon a phi C31 lysogen of S. coelicolor. Operator-constitutive (Oc) mutants of pCIA2 were isolated and the mutations lay in CIR6, i.e. CIR6:G14T and CIR6:C2A. Primer extension analysis of RNA prepared from an induced, temperature-sensitive lysogen of S. coelicolor localized a mRNA 5' endpoint 21 bp to the right of CIR6. The importance of the ap1/CIR6 region in the regulation of lytic growth was demonstrated by the analysis of a virulent mutant, phi C31 vir1, capable of forming plaques on an S. coelicolor phi C31 lysogen. phi C31vir1 contained a DNA inversion with the breakpoints lying within the integrase gene (which lies approximately 7 kbp to the right of CIR6) and in the essential early region between CIR6 and the -10 sequence for ap1. The separation of ap1 from its operator was thought to be the basis for the virulent phenotype in phi C31 vir1. Band-shift assays and DNase I footprinting experiments using purified 42 kDa repressor isoform confirmed that CIRs 5 and 6 were indeed the targets for binding of this protein. The 42 kDa repressor bound to CIR6 with higher affinity than to CIR5 in spite of their identical core sequences. Repressor bound at CIR6 facilitated binding at CIR5. The high-affinity binding to CIR6 was abolished with the Oc mutant, CIR6:G14T. Hydroxyl radical footprinting and dimethyl sulphate methylation protection of the 42 kDa repressor-CIR6 interaction suggested that the protein bound in the major groove and to one face of the DNA.

Bacteriophages↗

East and west of main street: racism in rural America.

This article describes the presence in three rural communities of racism uncovered during recent community-analysis projects. The roots of racism are viewed and analyzed from three theoretical perspectives. Based upon theoretical concepts, intervention strategies are described, and suggested methods of implementation are offered that can guide the community health nurse in the legitimation and empowerment of the various oppressed groups in the communities served.

Community Health Nursing↗

Growth patterns in selected organs of the miniature swine as determined by gross macromolecular composition.

As part of a larger study designed to characterize the early developmental stages of the Hormel-Hanford strain miniature pig, the brain, kidney, liver, pancreas, and spleen from male animals were examined for changes in RNA, DNA, and protein contents from 1 to 196 d after birth. Distinct patterns were found for changes with age in macromolecular levels. Protein levels increased from d 1 to 56 in all organs except spleen, in which little change was noted. Gel electrophoresis showed little qualitative change in the liver protein profile during this period. A fat-free, non-nucleic acid, protein-containing fraction, insoluble in hot alkali, appeared in the brain after approximately 1 wk following birth. DNA concentrations decreased markedly from d 1 to d 196 for brain, kidney, and spleen but decreased more gradually for liver and pancreas. RNA levels declined slightly or remained the same in all organs except pancreas, where a large increase occurred from d 1 to weaning (56 d). Growth proceeded in all organs by increases in cell number (hyperplasia), as evidenced by increases in total (level or concentration x organ weight) DNA, or by hypertrophy, as evidenced by increases in the ratio of protein to DNA or by a combination of both processes. Hypertrophic growth was attained by d 56 and continued to sexual maturity in all organs except spleen. Hyperplastic growth continued to sexual maturity in all organs except brain.

Aging↗

An integrative review and meta-analysis of oncology nursing research: 1981-1990.

The systematic accumulation of widely scattered research results is essential to developing a scientific basis for clinical practice. The purposes of this study were to describe 10 years of patient-related oncology nursing research in the United States, assess effectiveness of interventions, and test a prototype for research synthesis projects. Using a nursing framework and strategies of integrative research review and meta-analysis, 428 studies were selected for the study. The studies were found to be predominantly descriptive (90%), with convenience samples (79%), and a median sample size of 48. Subjects were predominantly in treatment or rehabilitation (52%), with demographic and stage of disease characteristics largely unreported. Of the 428 studies, 42 met the criteria for meta-analytic treatment. Interventions were found to be significantly effective, with membership in the intervention group improving success rate by 22%. The prototype was judged highly for adherence to standards and usefulness for adaptation to other research syntheses. Because of wide diversity in topics studied, missing information on subjects, and lack of replication, implications for research-based practice are premature at this time. Recommendations for future research include new studies, replications, and new research syntheses with an international scope for nurses studying and providing cancer care.

Nursing Research↗

Coma.

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Coma↗

An operator associated with autoregulation of the repressor gene in actinophage phiC31 is found in highly conserved copies in intergenic regions in the phage genome.

Previous reports have suggested that the repressor gene, c, of phiC31 is autoregulated and that likely operators are conserved inverted repeat sequences (CIRs1&2) located just upstream of the promoters, cp1 and cp2. Evidence is now presented that the CIRs 1&2 are indeed binding sites for one of the three inframe, N-terminally different protein isoforms of 42, 54 and 74 kDa produced by the c gene. A cp1-aphII fusion was repressed in a Streptomyces coelicolor A3(2) phiC31 lysogen and characterisation of an operator-constitutive (Oc) mutant showed a single mutation in CIR-1. CIR-1 containing fragments were retarded in electrophoresis gels by the 42 kDa repressor protein isoform and this retardation was inhibited by the addition of competing DNA fragments containing either CIR-1 or CIR-2. Using a combination of Southern blotting and analysis of available DNA sequence we also show that at least 18 copies of the CIRs are present throughout the phiC31 genome. Alignment of 9 CIR sequences showed that 8 contained a perfectly conserved 17 bp core whilst the exception had a single mismatch. The core includes a 16 bp inverted repeat (IR), and is usually part of a more extensive and less highly conserved palindrome. When superimposed on a previously derived transcription map of the early region, the CIRs lie in intergenic regions associated with transcription initiation and/or termination.

Bacteriophages↗

Effect of corticosteroid therapy on human immunodeficiency virus-associated nephropathy.

PURPOSE: Human immunodeficiency virus-associated nephropathy (HIV-AN) occurs predominantly in blacks and is characterized histologically by focal segmental glomerulosclerosis or mesangial proliferation and a lymphohistiocytic tubulointerstitial infiltrate. Patients manifest heavy proteinuria and, once azotemia occurs, progress rapidly to end-stage renal disease within 2 to 6 months. No treatment has been shown to be useful for HIV-AN. The purpose of this study was to determine the effect of corticosteroid agents on the progression of HIV-AN. PATIENTS AND METHODS: Four consecutive HIV-infected adults with fewer than 200 CD4 cells/microL, moderate to severe renal insufficiency, proteinuria greater than 2 g per 24 hours, and HIV-AN demonstrated by renal biopsy were treated with 60 mg of prednisone daily for 2 to 6 weeks. Patients were followed with respect to serum creatinine level, 24-hour protein excretion, adverse drug reactions, and the occurrence of opportunistic infections. RESULTS: CD4 counts ranged from 30 to 80 cells/microL before therapy with steroids. The mean (+/- SD) pretreatment serum creatine concentration was 9.1 +/- 5.7 mg/dL and decreased to 3.3 +/- 1.8 mg/dL (P < 0.05) after 2 to 6 weeks of corticosteroid therapy. Twenty-four hour protein excretion did not change (5.2 +/- 2.4 g pretreatment versus 4.6 +/- 4.1 g posttreatment). One patient was able to discontinue dialysis after 10 days. Two patients developed Mycobacterium avium-complex infections and steroid-associated psychosis. One of these patients developed a recurrence of genital herpes, and the other developed dermatomal zoster. None of the four required dialysis during a 1.5- to 5.5-month period of follow-up after cessation of steroid treatment. CONCLUSION: In selected patients with HIV-AN, short-term treatment with corticosteroid agents improves renal function and prevents the development of end-stage renal disease during a 1.5- to 5.5-month period of observation, but may be associated with an increased risk of opportunistic infection.

Adult↗