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Biomedical subjects

J Hewett

Publications and source records attributed to J Hewett.

31 records · Page 2Linked to original sources
PubMed1994

The DYT1 gene on 9q34 is responsible for most cases of early limb-onset idiopathic torsion dystonia in non-Jews.

Idiopathic torsion dystonia (ITD) is characterized by involuntary twisting movements and postures. A gene for this disorder, DYT1, was mapped to chromosome 9q34 in 12 Ashkenazi Jewish (AJ) families and one large non-Jewish kindred. In the AJ population, strong linkage disequilibrium exists between DYT1 and adjacent markers within a 2-cM region. The associated haplotype occurs in > 90% of early limb-onset AJ cases. We examined seven non-Jewish ITD families of northern European and French Canadian descent to determine the extent to which early-onset ITD in non-Jews maps to DYT1. Results are consistent with linkage to the DYT1 region. Affected individuals in these families are clinically similar to the AJ cases; i.e., the site of onset is predominantly in the limbs and at least one individual in each pedigree had onset before age 12 years. None carries the AJ haplotype; therefore, they probably represent different mutations in the DYT1 gene. The two French Canadian families, however, display the same haplotype. Estimates of penetrance in non-Jewish families range from .40 to .75. We identified disease gene carriers and, with adjustments for age at onset, obtained a direct estimate of penetrance of .46. This is consistent with estimates of 30%-40% in the AJ population. Two other non-Jewish families with atypical ITD (later onset and/or cranial or cervical involvement) are not linked to DYT1, which indicates involvement of other genes in dystonia.

Adolescent↗
PubMed1992

A randomized, double-blind, placebo-controlled trial to evaluate the effect of enalapril in patients with clinical diabetic nephropathy.

It is unknown if the antiproteinuric effect of angiotensin-converting enzyme (ACE) inhibitors reflects attenuation in the rate of progression of diabetic nephropathy. We report the results of a randomized, double-blind clinical trial designed to evaluate the longitudinal (18-month) effect of the ACE inhibitor, enalapril (5 to 40 mg/d), versus a placebo on 24-hour urinary protein excretion and on the rate of progression of renal disease in 33 patients with clinical diabetic nephropathy. Systemic blood pressure was controlled throughout the trial with conventional antihypertensive drugs. Glomerular filtration rate (GFR), determined by Tc99mDTPA renal clearance, and urinary protein excretion were monitored at 3-month intervals. Enalapril, in contrast to placebo therapy, was associated with an initial (40%) and sustained (33%) decrease in urinary protein excretion. Patients randomized to both enalapril or placebo experienced mean decreases in GFR, from 1.01 mL/s/1.73 m2 (61 mL/min/1.73 m2) to 0.85 mL/s/1.73 m2 (51 mL/min/1.73 m2), and from 1.06 mL/s/1.73 m2 (64 mL/min/1.73 m2) to 0.97 mL/s/1.73 m2 (58 mL/min/1.73 m2), respectively. Eleven of 18 patients (61%) randomized to enalapril, and 10 of 15 (66%) patients randomized to placebo, had a decrease in GFR; their rates of progression were -1.18 mL/min/1.73 m2/mo and -1.00 mL/min/1.73 m2/mo, respectively. In the absence of changes in blood pressure, the addition of an ACE inhibitor to patients with clinical diabetic nephropathy could not be shown to confer a unique renal protective effect. A prolonged decrease in 24-hour protein excretion could not be shown to predict attenuation in the progression of established clinical diabetic nephropathy.

Adult↗
PubMed1992

Relationship of changes in helplessness and depression to disease activity in rheumatoid arthritis.

We investigated the relationship between changes in helplessness and depression to disease activity in rheumatoid arthritis (RA). Sixty-three men with RA were examined at baseline, 3 months, and 6 months. Joint counts, immunophenotypic analyses of peripheral blood lymphocytes, and measures of psychological status were obtained at each examination. Zero-order correlations between psychological change and disease activity change from baseline to 6 months were not significant, but hierarchical multiple regression analyses revealed that changes in affective state were significantly related to joint counts at 6 months. Additionally, changes in absolute numbers of HLA-DR+ (human leukocyte antigen DR type) cells were significantly related to joint counts at 6 months. When absolute numbers of HLA-DR+ cells were entered prior to affective state in a hierarchical multiple regression, affective state was only marginally statistically significant. The study shows that longitudinal relationships between affective changes and disease activity are moderated by intervening variables such as immunologic activation.

Aged↗
PubMed1991

Adjustment to spinal cord injury: stage theory revisited.

To better understand adjustment following spinal cord injury (SCI), 106 subjects from two samples (N = 53 each) were administered the SCL-90-R, a symptom checklist, and the Multidimensional Health Locus of Control scales. Sample 1 subjects were admitted for rehabilitation during 1981 to 1982 and sample 2 subjects were admitted during 1984 to 1986. Sample 2 subjects entered rehabilitation programs more quickly after injury and reported more anxiety, phobic anxiety, and hostility than sample 1 subjects. Within each sample, there was no evidence for a relationship between age or time since injury and health beliefs or psychological distress. This study does not support stage theory for adjustment after catastrophic injury, but does suggest the importance of understanding the impact of social policy changes in adjustment following spinal cord injury.

Adaptation, Psychological↗
PubMed1991

Assessment of physician perceptions on the fatality of cancer.

A questionnaire was developed to evaluate internists' perceptions about patients' survival of cancer as compared with other diseases. The questionnaire consisted of four pairs of survival-matched cancer and non-cancer diseases. The questionnaire was administered to 42 faculty members and 37 resident physicians in the Department of Medicine at the University of Missouri-Columbia. Physicians rated patients' survival of cancer to be significantly lower than patients' survival of comparable non-cancer diseases (p less than 0.001). Resident physicians estimated patients' survival of breast cancer to be significantly lower (p less than 0.007) and estimated the survival of lung cancer to be significantly higher than the faculty members' estimate (p less than 0.003). These physicians' perceptions could adversely affect the quality of care and the degree of consideration given to both cancer and non-cancer patients. The differences observed in faculty members' and resident physicians' responses were attributed to the greater knowledge and clinical experience of faculty rather than differences in attitudes toward cancer.

Health Knowledge, Attitudes, Practice↗
PubMed1989

Reduction of spiral ganglion neurons in the aging canine with hearing loss.

The middle and inner ears of 16 dogs, from 1.5 to 17 years of age, with differing degrees of suspected hearing loss were examined. Auditory function was assessed subjectively, and electrophysiologically by recording brainstem auditory-evoked responses (BAER) to click stimuli. Ossicular chains and stapediovestibular articulations were evaluated macroscopically and by light microscopy for evidence of bony ankylosis; no abnormalities were found. A determination of spiral ganglion packing density revealed a loss of spiral ganglion cells in all areas of the cochlea in dogs of the deaf group and in the upper and lower basal region of dogs from the hearing impaired group. The largest losses of spiral ganglion cells in the deaf group were located in the upper and lower basal region. The deaf group's density was reduced to 44% (upper basal) 15% (lower basal) of the normal hearing group. The largest spiral ganglion cell loss for dogs in the hearing impaired group occurred in the lower basal region where the density was reduced to 40% of the normal hearing group. These morphological findings in the aging canine are consistent with a peripheral nerve hearing loss.

Aging↗
PubMed1987

Electrophysiologic testing in patients with unexplained syncope: clinical and noninvasive predictors of outcome.

To assess whether the level of risk of having significant electrophysiologic abnormalities can be determined, 29 clinical variables were analyzed in 104 patients with unexplained syncope who underwent electrophysiologic testing. A positive electrophysiologic study was defined as: a sinus node recovery time greater than or equal to 3 seconds; HV interval greater than or equal to 100 ms; infranodal block during atrial pacing; unimorphic ventricular tachycardia; and supraventricular tachycardia associated with hypotension. Thirty-one patients had a positive study, with inducible ventricular tachycardia being the most common finding (71% of positive studies). A left ventricular ejection fraction less than or equal to 0.40 was the most powerful predictor of a positive electrophysiologic study (p less than 0.00001), followed by the presence of bundle branch block (p less than 0.00003), coronary artery disease (p less than 0.0003), remote myocardial infarction (p less than 0.00006), use of type 1 antiarrhythmic drugs (p less than 0.00003), injury related to loss of consciousness (p less than 0.01) and male sex (p less than 0.01). A negative electrophysiologic study was associated with an ejection fraction greater than 0.40 (p less than 0.00001), the absence of structural heart disease (p less than 0.00001), a normal electrocardiogram (ECG) (p less than 0.0001) and normal ambulatory ECG monitoring (p less than 0.0001). The probability of a negative study increased as the number and duration of syncopal episodes increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Purification of prealbumin from human serum.

A method is presented by which prealbumin (thyroxine-binding prealbumin; tryptophan-rich prealbumin) may be purified to homogeneity from human serum. The method involves precipitation of contaminating proteins with dilute aqueous phenol, ion-exchange chromatography on DEAE-Sephacel, and gel permeation chromatography on Sephadex G-100. The yield is 25-30%, and the prealbumin is homogeneous by polyacrylamide gel electrophoresis at pH 8.9 and pH 3.6.

Chemical Precipitation↗
PubMed1980

Quantitative ultrastructural analysis of the human parietal cell during acid inhibition and increase of gastric potential difference by glucagon.

Glucagon inhibits gastric acid secretion and increases the negativity of gastric mucosal potential difference (PD) in man. To test the hypothesis that the increased negativity of PD after glucagon in man could be due to decreased parietal cell canalicular membrane area, a quantitative ultrastructural analysis was carried out. Four healthy volunteers with normal gastric mucosa were submitted to biopsy before and 20 minutes after intravenous injection of 2 mg glucagon (G). This time corresponded with the maximal change in PD and a decrease in gastric acid secretion. Canalicular and tubulovesicular membrane area of 80 parietal cells (40 cells before glucagon and 40 cells after glucagon) were quantified by the Loud morphometric method. After glucagon, the oxyntic cell canalicular membrane area was reduced by one-fourth (P less than 0.05), while tubulovesicular membrane area showed an increase (P less than 0.05) at the same time. The decrease in the area of parietal cell canalicular membrane caused by glucagon may in part be responsible for increased negativity of the gastric PD caused by this hormone.

Adult↗
PubMed1980

Human upper esophageal sphincter pressure profile.

The pressure profile of the upper esophageal sphincter was characterized in nine normal subjects. Directionally oriented intraluminal pressures were recorded, at 0.5-cm intervals over a 6-cm segment that encompassed the sphincter, by a high-fidelity low-compliance recording system. The peak resting pressure was directed posteriorly, and the lowest pressures were recorded from the lateral orientations. Significant axial asymmetry was observed with peak posterior pressure 0.55 cm more distal than the anterior pressure. Calculations of variability of pressures recorded at each interval showed the peak pressure to be the most reproducible measurement for each subject. Isotonic saline and acid infusions into the esophagus distal to the sphincter resulted in increased sphincteric peak resting pressure (acid greater than saline). There was axial lengthening of the sphincteric pressure zone with infusion of acid and saline, but this observed increase in length was not significant except at the 50 mmHg level. Pressure profiles recorded during 0.5-cm station pull-throughs were virtually identical to those obtained by a rapid continuous pull-through technique.

Adult↗
PubMed1979

Incidence of gastric lesions in patients with rheumatic disease on chronic aspirin therapy.

Endoscopy was done in 82 patients with rheumatic disease who were receiving chronic aspirin therapy. Fifty-eight patients were taking at least eight aspirin tablets daily for 3 or more months; 24 patients were taking, in addition to the aspirin, a maximum of one other antiinflammatory, nonsteroidal medication. Endoscopy in 45 normal subjects not taking aspirin showed no ulcers or erosions and a 4% incidence of gastric erythema. In the 82 patients with rheumatic disease, 14 (17%) had gastric ulcers, 33 (40%) had gastric erosions, and 62 (76%) had gastric erythema. Regular aspirin and buffered aspirin users had an ulcer incidence of 23% and 31% respectively, compared with a 6% incidence in enteric-coated aspirin users (P less than 0.05). One third of all patients with gastric ulcer had no gastrointestinal symptoms. Patients taking chronic aspirin therapy for rheumatic diseases have a higher than suspected incidence of gastric ulcer and erosions. Gastric ulcer may exist without symptoms in such patients.

Adult↗