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Biomedical subjects

D J Sharp

Publications and source records attributed to D J Sharp.

54 records · Page 3Linked to original sources
PubMed1995

Lung cancer in nonsmoking women. Histology and survival patterns.

BACKGROUND: Despite the widespread view that important clinical and etiologic differences exist between histologic categories of lung cancer, few studies have examined the accuracy of hospital-reported pathologic diagnoses of lung cancer. METHODS: A review of pathologic material and an assessment of survival patterns were conducted in conjunction with a recently completed case-control study of lung cancer among nonsmoking women in Missouri. Using established protocols, tissue slides from tumors of 482 patients were reviewed by 3 pathologists. RESULTS: Adenocarcinoma was the most common histologic type among former smokers and lifetime nonsmokers. The overall agreement rate between the original and review diagnoses was 65.6%. The positive predictive value ranged from 0.33 for bronchioalveolar carcinomas to 0.84 for adenocarcinomas. Agreement rates for small, medium, and large hospitals were 63.1, 66.6, and 66.2%, respectively. Survival rates were highest for bronchioalveolar carcinoma and lowest for small cell carcinoma. CONCLUSION: Given the importance of lung cancer to public health and the need to examine risk by histologic type, these data indicate that pathologic review of registry-reported lung cancer cases may be an important component of large scale studies of etiology.

Adenocarcinoma↗
PubMed1995

Transport of dendritic microtubules establishes their nonuniform polarity orientation.

The immature processes that give rise to both axons and dendrites contain microtubules (MTs) that are uniformly oriented with their plus-ends distal to the cell body, and this pattern is preserved in the developing axon. In contrast, developing dendrites gradually acquire nonuniform MT polarity orientation due to the addition of a subpopulation of oppositely oriented MTs (Baas, P. W., M. M. Black, and G. A. Banker. 1989. J. Cell Biol. 109:3085-3094). In theory, these minus-end-distal MTs could be locally nucleated and assembled within the dendrite itself, or could be transported into the dendrite after their nucleation within the cell body. To distinguish between these possibilities, we exposed cultured hippocampal neurons to nanomolar levels of vinblastine after one of the immature processes had developed into the axon but before the others had become dendrites. At these levels, vinblastine acts as a kinetic stabilizer of MTs, inhibiting further assembly while not substantially depolymerizing existing MTs. This treatment did not abolish dendritic differentiation, which occurred in timely fashion over the next two to three days. The resulting dendrites were flatter and shorter than controls, but were identifiable by their ultrastructure, chemical composition, and thickened tapering morphology. The growth of these dendrites was accompanied by a diminution of MTs from the cell body, indicating a net transfer of MTs from one compartment into the other. During this time, minus-end-distal microtubules arose in the experimental dendrites, indicating that new MT assembly is not required for the acquisition of nonuniform MT polarity orientation in the dendrite. Minus-end-distal microtubules predominated in the more proximal region of experimental dendrites, indicating that most of the MTs at this stage of development are transported into the dendrite with their minus-ends leading. These observations indicate that transport of MTs from the cell body is an essential feature of dendritic development, and that this transport establishes the nonuniform polarity orientation of MTs in the dendrite.

Animals↗
PubMed1994

Relationship between sleep patterns and human colonic motor patterns.

BACKGROUND/AIMS: The precise relationships among colonic motor patterns, depth of sleep, and awakening are incompletely understood. The aim of this study was to correlate human colonic motor patterns with sleep stage, nocturnal arousals, and waking. METHODS: We monitored sleep and correlated sleep stage, arousals, and waking with pressures (area under curve and propagating contractions) recorded from the entire colon in 11 healthy volunteers. RESULTS: Propagating contraction frequency (P = 0.01) and area under the curve (P = 0.001) were significantly reduced at night. There was a highly significant correlation between depth of sleep and suppression of area under curve (P = 0.001) and propagating contraction frequency (P = 0.0001). Propagating contractions were eliminated during slow-wave sleep. During rapid eye movement sleep, colonic pressure and propagating contraction frequency increased sharply to levels comparable with those found in stage 2 sleep. Transient arousal from stable sleep, with or without waking, was a potent and immediate stimulus for colonic propagating contractions. CONCLUSIONS: Sleep per se has a profound inhibitory effect on propagating and nonpropagating activity and is the major determinant of diurnal variation of colonic motility. Propagating contractions are eliminated in slow-wave sleep. Rapid eye movement sleep, arousals, and waking have immediate stimulatory effects on colonic motility.

Adolescent↗
PubMed1994

Diabetes-related end-stage renal disease in Missouri: trends and variations by age and race.

Diabetes-related end-stage renal disease (ESRD-DM) is a major source of morbidity and medical costs. The authors studied patterns of ESRD-DM in Missouri during the period 1985-1992. The incidence of ESRD-DM increased during this period, with the largest increase in older age groups. ESRD-DM is substantially more common among blacks than among whites. Enhanced efforts are needed to improve detection and control of diabetes and its complications, especially in high-risk populations.

Adult↗
PubMed1993

Exposure to environmental tobacco smoke among Missouri children.

Childhood exposure to environmental tobacco smoke (ETS) increases the risk of lower respiratory infections (e.g., bronchitis and pneumonia), exacerbates childhood asthma, and increases the prevalence of fluid in the middle ear. Using self-reported telephone survey data, we examined the attitudes and practices of Missouri residents related to ETS exposure of children. Ninety-five percent of all respondents believed that ETS exposure is harmful to children and the percentage was similar for households with children (96%) and without children (94%). ETS was present in 42% of households and the percentage was similar for households with children (41%) and without children (44%). Childhood exposure to ETS remains a problem in Missouri, despite widespread awareness of the hazards. More active intervention is needed to reduce ETS exposure in the home.

Adult↗
PubMed1993

Preventable mortality in Missouri: excess deaths from nine chronic diseases, 1979-1991.

For the period 1979-1991, 54% of the 644,045 deaths in Missouri were attributed to nine chronic diseases--cancers of the breast, uterine cervix, lung, colon/rectum; coronary heart disease; stroke; diabetes; chronic obstructive pulmonary disease; hepatic diseases/cirrhosis. Elimination of risk factors and screening have been shown to reduce the mortality caused by these diseases. To evaluate the range in excess mortality in the state, we calculated excess mortality by county and correlated these rates with three sociodemographic variables. Based on these analyses, an estimated 100,000 deaths may have been prevented through prevention and early detection activities.

Adult↗
PubMed1993

Patterns of obesity in Missouri.

Obesity is a major preventable health problem in Missouri and in the nation. Using survey data, we examined the prevalence of obesity in population subgroups and the overall trend. Prevalence of obesity was higher among blacks, middle-aged persons, and persons with less education or lower family income. Without additional attention, Missouri is unlikely to achieve the year 2000 objective of < or = 20% prevalence of obesity.

Adult↗
PubMed1991

Heterotopic bone formation after hip replacement. The influence of the type of osteoarthritis.

The relationship between heterotopic bone formation and the morphological type of osteoarthritis was examined after 43 hip replacements. Of the 43 hips studied, nine were atrophic, 19 were normotrophic, and 15 were hypertrophic. The incidence of heterotopic bone formation in the atrophic type was 11%, in the normotrophic type 32%, and in the hypertrophic type 87%. The difference between each type was statistically significant (p less than 0.001).

Aged↗
PubMed1990

Measurement of the density of trabecular bone.

Methods of assessing real and apparent trabecular bone density are discussed. A method of defatting trabecular bone using trichlorethylene in an ultrasound bath for 4 h followed by rehydration in distilled water under vacuum is described, and its effectiveness discussed.

Bone Density↗
PubMed1989

Adolescents and alcohol--a review of the recent British research.

There is evidence of increased alcohol consumption by young people. This review concentrates on the British epidemiological and psychological studies of adolescent drinking behaviour, with special reference to the cultural and developmental aspects. It is clear that drinking alcohol may be considered a normal part of adolescence and many young people are introduced to it by their parents. However, one area of concern is the amount of drunkenness reported. The way forward is to gain new insights into what drinking means to adolescents and how such meanings are propagated.

Adolescent↗
PubMed1988

Validation of the 30-item General Health Questionnaire in early pregnancy.

One-hundred-and-seventy-nine women attending their first antenatal clinic at two general practices in South London were asked to complete the 30-item General Health Questionnaire (GHQ-30) as part of a larger prospective longitudinal study into childbirth-related affective disorders. The women were later interviewed at home and a standardized psychiatric interview administered. Relative operating characteristic (ROC) curves were used to determine the optimum cut-off point on the GHQ-30. Thirty-five per cent of the women were high scores on the GHQ-30 (greater than or equal to 6) and 29% were found to be 'cases' at interview (CIS Overall Severity Rating greater than or equal to 2).

Adolescent↗
PubMed1986

The effects of posture on obstructive sleep apnea.

To determine whether the adoption of a more upright sleep posture would improve breathing and gas exchange in patients with obstructive sleep apnea syndrome (OSAS), 13 male patients with OSAS were studied during an all-night polysomnographic study while lying supine or sitting at a 60-degree angle. In the upright posture, the frequency of obstructive apnea was decreased (lying, 48.9 +/- 5.4/h; sitting, 19.6 +/- 6.9/h; p less than 0.0005) and arterial oxyhemoglobulin saturation (Sao2) was increased (nREM; mean lying, 90.6 +/- 0.8%; mean sitting, 92.1 +/- 0.5%, p less than 0.005; minimum lying, 64.8 +/- 3.2%, minimum sitting, 80.8 +/- 2.1%, p less than 0.005). In approximately half the patients studied, obstructive sleep apnea was essentially abolished by the postural intervention. These patients were more obese and had lower Pao2 and higher Paco2 values awake than the remaining patients in whom the response was either incomplete or absent. Arousal from sleep was less frequent in the upright posture, but sleep efficiency and overall sleep architecture were unchanged. This simple maneuver may be useful for treating some patients with OSAS.

Adult↗
PubMed1985

The Charnley total hip arthroplasty in patients under age 40.

Considering the high morbidity in young individuals, the authors reviewed 73 Charnley total hip arthroplasties in patients under age 40. The average follow-up period was 6.6 years. A total of 22 hips failed. Thirty-one hip arthroplasties were performed in normally ambulatory patients, with nine failures. Forty-two were performed in patients with limited locomotion, with 13 failures. The main cause of failure was loosening requiring revision (ten hips). There was radiologic evidence of progressive loosening in four other hips. Loss of trochanteric fixation required revision of six hips. Activity and rheumatoid disease were major contributing factors. Alternative methods of treatment should be considered in the young patient. When the operation is indicated, the greater trochanter must not be removed. It is hoped that cementless methods of fixation may produce a lower incidence of failure.

Adolescent↗
PubMed1984

The resolution of protrusio acetabuli treated with Ring's hip prosthesis.

Seven hips with protrusio acetabuli which showed complete or partial resolution of the protrusion after replacement with Ring's prosthesis are reported. It is suggested that this prosthesis offers a simple and effective method of treating painful protrusion into the pelvis; it allows healing of the medial wall of the acetabulum while avoiding many of the hazards of other methods of treatment.

Acetabulum↗