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Biomedical subjects

J Froehlich

Publications and source records attributed to J Froehlich.

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

Coronary artery calcification: assessment with electron beam CT and histomorphometric correlation.

PURPOSE: To assess the reliability of electron beam computed tomography (CT) in the detection of calcific deposits in coronary arteries. MATERIALS AND METHODS: The authors quantitatively evaluated a total of 4,298 segments of coronary arteries with electron beam CT and histomorphometry. RESULTS: Regression analysis of the electron beam CT calcium score versus histomorphometric calcium area produced an r2 value of .92 (r = .96; P < .0001). Ninety-three percent (78 of 84) of all coronary arteries with stenosis of 76%-100% contained calcific deposits, and 20% (17 of 83) of all coronary arteries with stenosis of 0%-50% contained calcific deposits. CONCLUSION: The amount of calcific deposits detected with electron beam CT correlates highly with histomorphometric measurements. Also, the amount of calcific deposits correlates well with the degree of coronary artery stenosis. Electron beam CT, therefore, is a promising noninvasive technique that can help depict the presence and extent of atherosclerotic plaques.

Adult↗
PubMed1994

Coronary artery disease: prediction with in vitro electron beam CT.

PURPOSE: To investigate the potential to predict coronary artery disease with electron beam computed tomography (CT). MATERIALS AND METHODS: Fifty heart specimens were examined with electron beam CT and histomorphometric techniques to measure calcific deposits as a percentage of blockage. RESULTS: In group A specimens (from cadavers of patients with symptomatic coronary artery disease), calcific deposits were identified at electron beam CT in 41% (584 of 1,426) of all segments of coronary arteries; in group B specimens (with asymptomatic coronary artery disease), in 24% (369 of 1,535) of all segments; and in the normal control specimens, in 4% (47 of 1,337) of all segments; segments (group A vs control specimens, P < .0001; group B vs control specimens, P = .02). On the basis of logistic regression analysis, coronary artery disease would be predicted if the average electron beam CT calcium score exceeds 0.32. The sensitivity and specificity of electron beam CT in the detection of calcific deposits per coronary artery was 94% and 76%, respectively. CONCLUSION: The electron beam CT calcium score appears to be an effective predictor of coronary artery disease.

Adult↗
PubMed1994

Receptor binding and signal transduction are dissociable functions requiring different sites on follicle-stimulating hormone.

Separate sites for glycoprotein hormone receptor binding and signal transduction have yet to be elucidated. In general, certain peptide regions are thought to be critical for receptor binding, whereas the oligosacharides are thought to be important for signal transduction. Using site-directed mutagenesis of FSH, we made selective amino acid substitutions and oligosaccharide alterations to try and identify specific sites mediating receptor binding distinct from signal transduction and vice versa. We substituted Lys or Asp for beta Arg35 in the purported receptor binding loop between cysteine-32 and -51, and we substituted Gln for alpha Asn52, alpha Asn78, beta Asn7, or beta Asn24, the attachment sites for each of the oligosaccharide side-chains. We determined the binding and signal-transducing activity of wild-type and mutant human FSH at the human FSH receptor, as recent data suggest that glycoprotein hormone-receptor interactions are species specific. The binding activities of FSH with Lys or Asp substituted for beta Arg35 were reduced 71% and 98%, respectively, but their signal transduction, at equivalent levels of binding activity, was unaffected. The binding activity of FSH lacking the oligosaccharide at alpha Asn52 was enhanced 2- to 3-fold, but its signal-transducing activity, at equivalent levels of receptor binding, was decreased 72%. In contrast, the binding and signal-transducing activities of FSH lacking the alpha Asn78, or alpha Asn7, or beta Asn24 oligosaccharide were unaffected. Thus, a specific amino acid (beta Arg35) is important for high affinity binding, but is not involved in signal transduction, whereas a specific oligosaccharide (alpha Asn52) is important for signal transduction, but is not required for high affinity binding. Therefore, receptor binding and signal transduction are dissociable functions involving different sites on the FSH glycoprotein.

Follicle Stimulating Hormone↗
PubMed1994

Increased biological activity due to basic isoforms in recombinant human follicle-stimulating hormone produced in a human cell line.

FSH has four asparagine-linked oligosaccharides with variable sialic acid contents, so that FSH is not a single molecule, but a heterogeneous group of isoforms. These isoforms differ in their biological properties and their distribution changes in various physiological states, allowing the modulation of FSH activity. Recombinant human (h) FSH has been produced in Chinese hamster ovary cells and has an isoform profile similar to those of both pituitary FSH standard and purified urinary FSH. These FSH preparations, however, do not contain the full spectrum of FSH isoforms found in the circulation. Production of recombinant hFSH in a cell line with a different pattern of glycosylation could broaden its isoform profile and potentially alter its biological activity. Thus, we transfected human embryonal kidney cells (293) with the human alpha and FSH beta genes to produce recombinant hFSH (hFSH-293) and determined its biological activity in a rat granulosa cell bioassay. Although hFSH-293 was immunologically indistinguishable from pituitary FSH standard, its biological potency was 3- to 6-fold higher than those of two different pituitary FSH standards. To investigate this increased potency, we separated the isoforms of hFSH-293 by chromatofocusing and determined their biological potencies in the rat granulosa cell bioassay. The isoform profile of hFSH-293 demonstrated a greater number of basic isoforms than that of pituitary FSH standard. Several of these basic isoforms exhibited enhanced in vitro biological potency, accounting for the increased biological potency of hFSH-293. This pattern of high in vitro biological activity and more basic isoforms is analogous to the FSH circulating during GnRH stimulation, pubertal induction, and ovulation.

Animals↗
PubMed1994

[Lipid peroxidation, antioxidant enzyme activity and trace element concentration in II and III trimester of pregnancy in pregnant women with diabetes].

UNLABELLED: The aim of the study was to evaluate the concentration of malondialdehyde (MDA)--end product of lipid peroxidation, activity of antioxidant enzymes: superoxide dismutase (CuZn-SOD), glutathione peroxidase (GSH-Px), and catalase (Cat) as well as selenium (Se), zinc (Zn) and copper (Cu) concentration in erythrocytes in 63 patients divided into the three groups: I--control group, II--normal pregnancy, III--pregnant type I diabetics. All parameters were investigated in hemolysate of erythrocytes. MDA concentration increased significantly in pregnant women when compared with control group, as well as in pregnant diabetics when compared with healthy pregnant women. The activity of GSH-Px decreased significantly in pregnant diabetics in comparison with groups I and II. The activity of CuZn-SOD and Cat was significantly lower in III group than in control group. The concentration of Se and Zn decreased, and the concentration of Cu increased significantly in pregnant diabetics in comparison with the other groups. No differences in concentration of MDA, Se, Zn, Cu and activity of GSH-Px were found between particular trimesters in studied patients. The activity of CuZn-SOD and Cat were significantly higher in III trimester than in II one in pregnant diabetics while the activity of GSH-Px remained unchanged during pregnancy. CONCLUSIONS: Increased lipid peroxidation and the lack of compensatory mechanisms--an increase in antioxidant enzymes activity as well as disorder of trace elements concentration are found in pregnant type I diabetics.

Adolescent↗
PubMed1993

Women's mental health: implications for occupational therapy.

This article describes issues of sexism in the mental health profession. Theoretical bias in psychiatry and the sociopolitical status of women are both linked to the inappropriate mental health treatment of women. A relational model of women's psychological development is offered as an alternative theoretical perspective for understanding the mental health needs of women. Ways to integrate this perspective in occupational therapy practice are included.

Activities of Daily Living↗
PubMed1991

Effect of decreased retinal illumination on simultaneously recorded pattern electroretinograms and visual-evoked potentials.

Sixteen normal subjects and three patients with optic neuritis were studied to determine the effect of decreased retinal illumination on simultaneously recorded pattern electroretinograms (PERG) and visual-evoked potentials (VEP). Using neutral-density filters (NDF), it was found that linear modeling is an excellent fit for VEP/PERG amplitudes and latencies as log functions of retinal illumination, both for individual eyes and averages of pooled data. Within narrow statistical limits, regression slopes show that mean PERG B-wave and VEP P100 latencies are affected almost identically by decreased illumination, leaving the mean retinocortical time (RCT) virtually unchanged. However, mean B-wave amplitude was greatly reduced at retinal illuminations at which P100 amplitude was unaffected. Of clinical significance was that these latency and amplitude effects were found in each eye tested, whether normal or pathologic. In particular, the RCT in normal subjects was never found to be statistically abnormal due to decreased retinal illumination, and it faithfully represented the optic nerve lesion in the patients with optic neuritis. This result was applied to a population of eight patients with uncomplicated cataracts. The significance of these results is discussed.

Adolescent↗
PubMed1990

Diarrhea and intestinal invasiveness of Aeromonas strains in the removable intestinal tie rabbit model.

Twelve Aeromonas strains were tested for virulence by using the removable intestinal tie adult rabbit diarrhea model. Mortality was 50% or greater for 7 of 12 strains; 23 of 37 rabbits that died developed diarrhea before death, and 11 of 27 surviving rabbits developed diarrhea. Aeromonas bacteremia was detected in 36 of 37 (97%) animals that died, but only in 2 of 27 (7%) survivors. Death, diarrhea, and bacteremia were all strongly strain dependent. Gastrointestinal lesions varied from moderate focal enteritis to severe multifocal necrosis and hemorrhage of the ileal mucosa, often accompanied by hepatic and splenic lesions. Intestinal colonization assays performed after infection indicated that the ileum was the most heavily colonized portion of the gut and the probable site of invasion. The application of the removable intestinal tie adult rabbit diarrhea model for intestinal challenge with Aeromonas strains has shown that some isolates are capable of invading the mucosa of rabbits, causing diarrhea and bacteremia. These data suggest that such strains may be important in causing human invasive diarrhea.

Aeromonas↗
PubMed1990

Use of the Role Checklist with the patient with multiple personality disorder.

A paucity of occupational therapy evaluation tools exists for use with patients with multiple personality disorder. The Model of Human Occupation (Kielhofner & Burke, 1980), particularly the volition and habituation subsystems within this model, proved useful for the identification of the many facets of patients with multiple personality disorder on a short-term treatment unit. The Role Checklist (Oakley, Kielhofner, Barris, & Richler, 1986), a tool derived from the Model of Human Occupation, was adapted for use with this population and was found to be beneficial in the identification of common goals held by most of the personalities of each patient with multiple personality disorder. The use of the Role Checklist is illustrated with a case example.

Acting Out↗
PubMed1986

Affective meanings of life review through activities and discussion.

Life review is often incorporated into therapy with the elderly in the form of verbal or activity groups. This study compares the affective meanings of life review through activities with life review through discussion. Twenty-two women between 60 and 85 years of age participated in one of two activity groups or in one of two discussion groups. Individuals in the activity groups expressed a positive event or accomplishment of their past by drawing and making collages. Then they discussed their finished products. In the discussion groups, subjects took turns describing a positive life event to other group members. Afterward, all subjects rated how they felt about themselves during the group using Osgood's semantic differential scale. Analyses of variance for nested designs were completed on the scale's evaluation, power, and action factors of affective meaning. They revealed significant differences between the groups within the activity and discussion conditions. However, differences between the activity and discussion conditions were not significant. In terms of clinical practice, life review was perceived as good, powerful, and active by this sample, and practitioners are urged to consider the importance of group-to-group differences in responses to activities.

Aged↗
PubMed1981

Biweekly prophylactic doxycycline for travelers' diarrhea.

A double-blind study to determine the efficacy of biweekly oral doxycycline in the prevention of travelers' diarrhea was conducted among 46 Peace Corps volunteers during their first six weeks in Honduras. The volunteers took either 100 mg of doxycycline per dose or a placebo for three weeks and were observed for an additional three weeks. There was no significant difference in the number of persons with travelers' diarrhea in the two groups (eight of 24 in the doxycycline group and 10 of 22 in the placebo group) in the three weeks when the drug was taken. However, significantly fewer episodes (P less than 0.05) of travelers' diarrhea occurred in the doxycycline group than in the placebo group at the end of the second, third, and fourth weeks. Enterotoxigenic Escherichia coli (ETEC) was the most common pathogen identified. ETEC from 13 (62%) of 21 stool samples were resistant to doxycycline. Biweekly doxycycline was only marginally effective in preventing travelers' diarrhea and did not prevent diarrhea secondary to doxycycline-resistant ETEC.

Adult↗