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Biomedical subjects

D Shore

Publications and source records attributed to D Shore.

108 records · Page 6Linked to original sources
PubMed1983

Effect of a comprehensive nutritional program on the growth and ponderosity of infants.

One hundred eighty-two consecutive newborns from a university-based private practice were enrolled in a comprehensive nutritional program in an attempt to lower the incidence of ponderosity in the group. The program emphasized an individualized approach in which the feeding instructions given to parents varied with the growth pattern of their child. Whereas specific modalities of feeding, such as breast vs. bottle and early vs. late addition of baby foods, appeared not to modify growth, the group as a whole exhibited a trend to lower weight-for-length index (WLI) and less ponderosity than in previous published reports. We propose that the individualized nutritional program may have resulted in this improvement, and that such attention to detail will likely be more rewarding than an approach which emphasizes only general nutritional information to the group as a whole.

Adult↗
PubMed1983

Improving accuracy in the diagnosis of Alzheimer's disease.

During a longitudinal study of outpatients with early Alzheimer's disease, several patients were found to have been incorrectly diagnosed as having a progressive dementia; case histories of three such patients are presented. Certain objective tests of dementia (The Extended Scale for Dementia, Mini-Mental Status, etc.) and language functions (The Porch Index of Communicative Ability), as well as The London Psychogeriatric Rating Scale (completed by a family member), have been found useful and are described briefly. The importance of reevaluating demented patients to document the course of their illness is emphasized to improve the accuracy of diagnosis in suspected cases of Alzheimer's disease.

Alzheimer Disease↗
PubMed1982

Cerebrospinal fluid zinc concentrations in ex-heroin addicts and patients with schizophrenia: some preliminary observations.

Mean CSF zinc concentration was lower in a group of ex-heroin addicts than in groups of normal controls and neuroleptic-treated schizophrenic patients, but values were generally within the normal range of CSF zinc concentrations. There were no significant differences in mean CSF zinc concentrations between groups of drug-free schizophrenic patients, schizophrenic patients on neuroleptics, and normal controls. CSF zinc concentration may be influenced by differences in racial composition and related dietary and other habits of the groups studied.

Adult↗
PubMed1982

Research design issues: antialuminum drug studies in Alzheimer's disease.

Alzheimer's disease is a common dementia of later life for which no effective treatments are yet available. Aluminum has been implicated in the pathophysiology of Alzheimer's disease, and interventions aimed at preventing aluminum neurotoxicity and clinical deterioration have been proposed. Carefully designed protocols are needed to test the efficacy of antialuminum drugs. Such protocols will need to be quite different from those used to test symptomatic treatments for Alzheimer's disease patients. A number of research design problems are discussed with regard to testing antialuminum drugs in humans.

Aged↗
PubMed1981

DNA flexibility studied by covalent closure of short fragments into circles.

The ring closure probability, or j factor, has been measured for DNA restriction fragments of defined sequence bearing EcoRI cohesive ends and ranging in size from 126 to 4361 base pairs (bp). The j factor is defined as the ratio of the equilibrium constants for cyclization and for bimolecular association via the cohesive ends. The end-joining reactions are fast compared to covalent closure of the cohesive ends by T4 DNA ligase. The rate of ligase closure is shown to be proportional to the equilibrium fraction of DNA molecules with joined cohesive ends, both in cyclization and in bimolecular association reactions. The j factor changes by less than 10-fold between 242 and 4361 bp, whereas it decreases by more than 100-fold between 242 and 126 bp as the DNA reaches the size range of the persistence length (150 bp). As regards ring closure, short DNA fragments are surprisingly flexible. These data are in good agreement with predictions by others for the ring closure probability of a wormlike chain.

DNA Ligases↗
PubMed1981

Mechanisms of mitral valve motion during diastole.

To examine the mechanisms of mitral valve motion in mid diastole and at closure, we simultaneously measured mitral flow (electromagnetic), valve motion (echo), and atrioventricular pressures (micromanometer). Peak valve excursion (E point) occurs early 46 +/- 7 ms) after opening and always precedes peak flow; therefore, mid-diastolic closing motion (EF slope) is not due to flow deceleration or vortex formation. Large variations in peak flow are accompanied by small variations in valve excursion (coefficient of variation 41 vs. 12%, respectively). We conclude that the valve overshoots its equilibrium position and that the chordae produce tension on the valve during diastole. This approach is supported by data from papillary muscle rupture, prolonged P-R interval, and mathematical modeling. We offer a valve-closure theory unifying chordal tension, flow deceleration, and vortices, with chordal tension as a necessary condition for the proper function of the other two. Nevertheless, prolonged periods of diastasis and ventricular premature contractions indicate that competent valve closure may occur in the absence of vortices and flow deceleration.

Animals↗
PubMed1980

Increased renal neuroleptic binding in spontaneously hypertensive rats.

The present experiments demonstrate high affinity stereospecific binding of the dopaminergic ligand [3H]spiroperidol to rat renal membranes. The binding was saturable, regionally distributed, and showed the same specificity as the caudate [3H]spiroperidol site for displacement by dopaminergic antagonists. Since there is an association between hypertension and abnormalities of renal blood flow, which appears to be regulated in part by dopamine, [3H]spiroperidol binding was measured in kidneys of spontaneously hypertensive rats. In two independent experiments renal cortical [3H]spiroperidol stereospecific binding was increased in spontaneously hypertensive rats.

Animals↗
PubMed1980

Serum parathyroid hormone concentrations in senile dementia (Alzheimer's disease).

The accumulation of aluminum in the cerebral cortex has been implicated as a factor in the pathogenesis of Alzheimer type senile dementia (SD) and in the dialysis dementia found in patients with chronic renal failure on long-term intermittent hemodialysis treatment. In animal studies, parathyroid hormone (PTH) produces increased absorption of aluminum from the gastrointestinal tract and elevations of aluminum in the cerebral cortex. It has been proposed that PTH elevations may increase tissue aluminum loads in patients with senile dementia. The present study was undertaken to investigate the status of circulating PTH in patients with SD and age/sex matched controls. No significant differences were found between these groups. Elevated PTH (when it did occur) seemed to be related to the degree of renal impairment rather than dementia. Differences in the distribution of aluminum in patients with dialysis dementia and SD are discussed.

Aged↗
PubMed1978

Determination of capsid size by satellite bacteriophage P4.

Satellite bacteriophage P4 requires all morphogenic gene products provided by a helper phage, such as coliphage P2, to assemble its own capsid, which is one-third the volume of the larger helper capsid. We have isolated a satellite phage P4 sid (size determination) mutant that is unable to direct the assembly of the small wild-type-size P4 capsid. Instead, this mutant produces P4 plaque-forming units with large P2-size capsids which contain two or three copies of the P4 sid1 genome. P4 sid1 is evidently mutated in a protein that is specifically responsible for determining the precise size and symmetry of the structure into which the helper P2 gene products will assemble. In addition, we have found that the physical size of the genome does not appear to play an essential role in the proper assembly of the icosahedral capsid, since the majority of the P4 sid1 plaque-forming units do not contain a complete capsidful of DNA.

Coliphages↗
PubMedDate not supplied

Perforation of the right aortic valve cusp: complication of ventricular septal defect closure with a modified Rashkind umbrella.

An 18-month-old boy with a perimembranous ventricular septal defect (VSD) had undergone transcatheter closure of the defect with a modified 17 mm Rashkind umbrella device at age 4 months (weight 3.8 kg). The clinical signs of a VSD persisted, and he developed aortic incompetence, first detected 5 months after the procedure, which progressed from mild to moderate. A three-dimensional echocardiographic study demonstrated that one of the four arms holding the umbrella was protruding into the aortic valve and had perforated the right aortic valve cusp. This diagnosis was confirmed at subsequent surgery. Surgical repair of the perforated right aortic valve leaflet was necessary. The umbrella was adherent to the tricuspid valve and could not be removed. Instead it was left in situ, but three of the stainless steel arms were cut off. When umbrella closure of a perimembranous VSD is undertaken, the close proximity of part of the distal umbrella to the aortic valve can lead to aortic regurgitation.

Aortic Valve↗