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Biomedical subjects

R S Wilson

Publications and source records attributed to R S Wilson.

At least 325 records · Page 18Linked to original sources
PubMedDate not supplied

Pathological changes in frontal cortex from biopsy to autopsy in Alzheimer's disease.

We evaluated the change in density of total senile plaques, plaque subtypes, and neurofibrillary tangles, from biopsy to autopsy in left frontal cortical sections from four patients with clinically typical Alzheimer's disease (AD). Comparisons were made on sections stained with modified Bielschowsky and Thioflavin S. In two cases, comparisons were also made on tissue stained with a monoclonal Alz-50 antibody and an antiserum to A beta (beta-amyloid protein). Despite a marked decline in mental status over several years of follow-up clinical evaluations, there was no consistent significant change in numerical density of plaques or tangles among the four cases. However, we did find fewer primitive plaques in the autopsy specimens. These results from longitudinally evaluated persons with typical AD suggest that although plaques and tangles may serve as adequate markers of the presence of AD, their numerical density within a single neocortical region may not reflect dementia severity. This conclusion supports the results of recent cross-sectional studies on the progression of pathology among persons with AD.

Alzheimer Disease↗
PubMedDate not supplied

Methadone combined with clonidine versus clonidine alone in opiate detoxification.

The availability and use of a methadone/clonidine combination versus clonidine alone in opiate detoxification were studied. In Phase I of the study, a sequential combination of methadone followed by clonidine was utilized in those patients presenting with a primary diagnosis of opiate dependence. During the Phase II of the study, only clonidine was available. Medications were administered only if the history and clinical findings indicated impending or acute opiate withdrawal syndrome. Overall, there was no difference between the Phase I and Phase II groups when the number of opiate dependent admissions, patients completing detoxification, and the patients completing a follow-up rehabilitation program were compared. However, the patients in Phase I whose clinical symptomatology warranted the use of methadone were more likely to complete the detoxification program when compared to the patients in Phase II who received clonidine only. There was no difference between the two groups in completion of a follow-up rehabilitation. Detoxification with clonidine alone was more likely to be successful if the patient has had prior detoxification experience with methadone or if there was a secondary dependence of alcohol, sedative, or tranquilizer present coexisting with the primary opiate dependence diagnosis.

Adolescent↗
PubMedDate not supplied

MRI-derived entorhinal and hippocampal atrophy in incipient and very mild Alzheimer's disease.

With high resolution, quantitative magnetic resonance imaging (MRI) techniques, it is now possible to examine alterations in brain anatomy in vivo and to identify regions affected in the earliest stages of Alzheimer's disease (AD). In this study, we compared MRI-derived entorhinal and hippocampal volume in healthy elderly controls, patients who presented at the clinic with cognitive complaints, but did not meet criteria for dementia (non-demented), and patients with very mild AD. The two patient groups differed significantly from controls in entorhinal volume, but not from each other; in contrast, they differed from each other, as well as from controls, in hippocampal volume, with the mild AD cases showing the greatest atrophy. Follow-up clinical evaluations available on 23/28 non-demented patients indicated that 12/23 had converted to AD within 12-77 months from the baseline MRI examination. Converters could be best differentiated from non-converters on the basis of entorhinal, but not hippocampal volume. These data suggest that although both the EC and hippocampal formation degenerate before the onset of overt dementia, EC volume is a better predictor of conversion.

Aged↗
PubMedDate not supplied

Alzheimer's disease: in vivo detection of differential vulnerability of brain regions.

The severe cognitive impairment during the later stages of Alzheimer's disease is usually preceded by a selective disturbance in the ability to remember new experiences. With quantitative, high-resolution magnetic resonance imaging techniques, it is now possible to determine, in vivo, differences in the pattern of anatomical changes that might reflect behavioral symptomatology during different stages of the disease. In the present investigation, magnetic resonance imaging examinations were carried out in aged controls and in clinically diagnosed Alzheimer's disease patients who were divided into three groups based upon dementia severity. Atrophy of the hippocampal formation, a region important for memory function, was observed even in Alzheimer's disease patients with the mildest dementia. With more prominent dementia, atrophy extended to the parahippocampal gyrus and the temporal neocortex.

Adult↗
PubMedDate not supplied

Topical antibiotic ointments for staphylococcal nasal carriers: survey of current practices and comparison of bacitracin and vancomycin ointments.

One measure used in the management of staphylococcal disease outbreaks in newborn nurseries is to obtain nasal cultures from nursery personnel and then treat nasal carriers with topical antibiotic ointments. Because recent infection control guide-surveyed current practices in larger hospitals in the U.S.A. Seventy-one percent of respondents indicated that they would obtain nasal cultures from personnel during a staphylococcal disease outbreak, and 40% indicated that they would prescribe topical antibiotic ointments for personnel with positive nasal cultures before the results of bacteriophage typing became known. Because little has been written about the efficacy of topical intranasal antibiotics within the past decade, we compared bacitracin ointment with a vancomycin ointment for treatment of the staphylococcal nasal carrier state. Both ointments reduced nasal carriage in the majority of instances. However, similar reduction was also observed in an untreated control group. The need for different approaches to the problem of nasal carriers is discussed.

Administration, Topical↗
PubMedDate not supplied

Twin growth: initial deficit, recovery, and trends in concordance from birth to nine years.

Height and weight measurements for a large sample of twins from birth to nine years were used to construct growth curves for this period. Compared to singletons, twins were substantially smaller at birth, particularly for weight (30% deficit), but the latter showed a dramatic recovery in the first 3 months, then smaller increments until finally reaching the singleton norms at 8 years. Height, while less depressed at birth (17% deficit), was also slower to recover during the first year, then moved in comparable increments with weight until reaching parity with singletons. Prenatal influences on birth size were largely dissipated as each twin converged on his/her genetic growth curve. Monozygotic twins became progressively more concordant with age (R = 0.94 for height), while dizygotic twins became less concordant (R = 0.49). Ten monozygotic pairs with large birth-weight differences (greater than 750 g) were examined at 6 years; the smaller twin was still significantly lighter (P less than 0.01), marginally shorter (P less than 0.10), but not significantly lower in IQ. The results suggested a high degree of buffering for intelligence against the effects of nutritional deficit in the prenatal period. Some factors in addition to placental anastomosis are suggested as a possible basis for long-term size differences in monozygotic pairs.

Birth Weight↗
PubMedDate not supplied

Socioeconomic characteristics of the community in childhood and cognition in old age.

We examined the relation of early life socioeconomic circumstances to cognition in older residents of a biracial urban community. Participants had brief cognitive testing three times at approximately 3-year intervals. At baseline, information about early life household and county socioeconomic level was collected. In mixed-effects models adjusted for age, sex, race, and education, both early life household and county socioeconomic levels were positively associated with baseline level of cognition but unrelated to cognitive decline. The results suggest that socioeconomic conditions in early life are associated with level of cognitive function in old age but not with rate of cognitive decline.

Black or African American↗
PubMedDate not supplied

Effect of ontogenetic increases in body size on burst swimming performance in tadpoles of the striped marsh frog, Limnodynastes peronii.

The effect of ontogenetic increases in total length on burst swimming performance was investigated in tadpoles of the striped marsh frog (Limnodynastes peronii) over the total-length range of 1. 5-4 cm and Gosner developmental stages 25-38. The burst swimming performance of tadpoles at 10 degrees and 24 degrees C was determined by videotaping startle responses with a high-speed video camera at 200 Hz and analysing the sequences frame by frame. Maximum swimming velocity (Umax) and acceleration (Amax) increased with total length (L) at a rate that was proportionally greater than the increase in total length (i.e., positive allometry; exponents >1) and was described by the allometric equations Umax=0.061L1.34 and Amax=1.15L1.11 at 10 degrees C and Umax=0.114L1.34 and Amax=1.54L1. 11 at 24 degrees C. Stride length increased with a total-length exponent of approximately 1 but was unaffected by temperature. Tail-beat frequency was not affected by total length and increased from 7.8+/-0.2 Hz at 10 degrees C to 21.7+/-0.7 Hz at 24 degrees C. Developmental stage did not significantly influence the relationship between total length and Umax or Amax. Furthermore, temperature and the associated changes in water viscosity did not affect the relationship between total length and burst swimming performance. At their Umax, Reynolds numbers ranged from approximately 1,500 in the smaller tadpoles up to 50,000 for the larger animals at 24 degrees C. We suggest the positive allometry of Umax in larval L. peronii was due in part to the increases in tail width (TW) with total length (TW=-1.36L1.66), possibly reflecting the increasing importance of burst swimming performance to survival during larval development.

Animals↗
PubMedDate not supplied

Epilepsy and verbosity.

Stories were elicited from 29 epileptic patients with generalized, simple partial, and complex partial seizures with bilateral, right, or left foci, and from 32 persons in two control groups. Four older epileptic patients with long histories of left complex partial seizures were verbose. Their stories involved trivial and subjective details, consistent with circumstantiality and suggesting the substrate for a hallucinatory syndrome.

Adolescent↗
PubMedDate not supplied

Effect of mechanical ventilation with end-inspiratory pause on blood-gas exchange.

The effects of end-inspiratory pause (EIP) on gas exchange were measured in 10 adult patients with acute respiratory insufficiency while maintained on mechanical ventilation. Four inspiratory patterns were studied with a constant tidal volume (10 to 15 ml/kg body weight), respiratory rate (9 to 12 breaths/min), FIO2 (0.5) and end-expiratory pressure. Inspiratory flow rate (V insp) and EIP time were varied to produce a control pattern (V insp = 60 L/min, EIP = 0), 2 EIP patterns of 0.6 and 1.2 seconds with a similar V insp and a "slow" flow pattern (V insp = 30 L/min) without EIP. The control pattern was applied before and after each study period. Arterial oxygenation was unchanged with both EIP and "slow" flow patterns when compared to control. Dead-space ventilation (VD/VT) and Paco2 were significantly decreased (p less than 0.01) as EIP was increased from 0 to 1.2 seconds, but remained unchanged with slow inspiratory flow. Thus, EIP improved the efficiency of ventilation with no apparent improvement in oxygenation in patients with acute respiratory insufficiency.

Adult↗
PubMedDate not supplied

Diphenylhydantoin teratogenicity: ocular manifestations and related deformities.

This patient illustrates a classical case of what many pediatricians call the diphenylhydantoin teratogenic syndrome. It suggests the possibility of an additional ocular finding of retinoschisis and optic nerve abnormalities which could conceivably have a teratogenic basis. The effects of epilepsy and diphenylhydantoin on these formations is discussed.

Abnormalities, Drug-Induced↗