Biomedical subjects
Publications and source records attributed to M D Wilson.
Pathologic disturbances in breathing in children become clinically apparent in the syndrome of obstructive sleep apnea. The surgical approach to this syndrome is often removal of hypertrophied tonsils and adenoids. The preoperative, operative, and postoperative concerns with special attention to the role of anesthesia are reviewed.
OBJECTIVE: To review the existing data on the use of diuretics or beta-blockers as first-line therapy for the treatment of mild to moderate hypertension, and to examine the issues surrounding the impact of these classes as well as the angiotensin-converting enzyme (ACE) inhibitors, calcium-channel blockers (CCBs), alpha-blockers, and alpha-beta-blockers on cardiovascular risk factors and cardiovascular morbidity and mortality. DATA SOURCES: A MEDLINE search of applicable articles on antihypertensive therapies and their impact on morbidity and mortality. In addition, a MEDLINE search of relevant articles regarding cardiovascular risk factors and the influence of the various antihypertensive therapies on these parameters. DATA SYNTHESIS: The literature was evaluated with regard to outcome. Trials examining the impact of antihypertensive pharmacotherapy, primarily with diuretics and beta-blockers, have shown them to decrease the incidence of stroke by 33-50 percent. However, their effect on coronary heart disease has been disappointing, showing only a 14 +/- 5 (mean +/- SD) percent decrease. Examination of numerous clinical trials assessing the impact of the various antihypertensive therapies on cardiovascular risk factors, including blood pressure, plasma lipids, diabetic control/insulin sensitivity, and left ventricular hypertrophy was done. The classes included beta-blockers, diuretics, alpha-blockers, ACE inhibitors, and CCBs; the results show a diversity of effect. Diuretics and beta-blockers tend to worsen cardiovascular risk status, whereas the alpha-blockers, ACE inhibitors, and CCBs all show a beneficial effect. CONCLUSIONS: Diuretics and beta-blockers can effectively reduce cerebrovascular morbidity and mortality, but have a limited effect on reducing cardiovascular disease, especially myocardial infarction. This may be explained, at least in part, by the negative, or lack of positive, effect on individual patients' overall cardiovascular risk status.
Mutation and allelic loss of the p53 gene have been demonstrated in a variety of human cancers. In this study, DNA was extracted from formalin-fixed paraffin sections of ovarian carcinoma from 33 patients informative for a restriction fragment length polymorphism (RFLP) for BstU 1 within the 4th exon of the p53 gene. Allelic loss of p53 as indicated by loss of heterozygosity for this RFLP was demonstrated in 16/33 cases (48%). Because immunoreactivity for p53 correlates closely with the presence of mutation in the p53 gene, we performed immunohistochemical staining with the monoclonal antibody PAb1801. Diffuse nuclear p53 immunoreactivity was observed in 16 of the 33 (48%) informative cases used for loss of heterozygosity analysis (37/80 (46%) cases of ovarian carcinoma overall). A significant correlation (Fisher's exact test, P = 0.04) was observed between p53 overexpression and allelic loss. We found no evidence of association of p53 allelic loss or overexpression with advanced stage or other clinical or pathologic prognostic parameters. We conclude that mutation and allelic loss of p53 are common and probably related events in the development of ovarian carcinoma. This study demonstrates the use of paraffin sections in the analysis of p53 alterations in neoplasia.
This study was conducted to determine male adolescent behavior, attitudes, and knowledge concerning the use of condoms. Subjects were 241 sexually active black adolescent males attending an inner-city adolescent medicine clinic who were surveyed using a structured interview technique. Factors associated with condom use included higher grade level, > or = 2 sexual partners in the past six months, communication about contraception with sexual partner(s), desire for sexually transmitted disease (STD) prevention when contracepting, and parental suggestion to use condoms. Variables not associated with condom use included older age, minimal level of knowledge about condom use, history of having impregnated a partner or of having contracted an STD, desire for pregnancy prevention, suggestion by friends to use condoms, or partner dissatisfaction with condoms. Using multivariate logistic regression analysis, the following variables in combination were able to correctly classify respondents as condom users or nonusers in 74% of cases: higher knowledge score, reported communication about contraception with one's partner(s), > or = 2 partners in the past six months, and higher socioeconomic status. These findings suggest that, for the study population, interventions directed toward improving knowledge about condoms, school achievement, and communication with parents and partners may be effective in increasing condom use.
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Adult female Simulium damnosum s.l. flies obtained in nine countries of the Onchocerciasis Control Programme were examined for 14 morphological characters with the aim of selecting specific characters to identify the main species that form the complex. Two approaches were used, the first involved discriminant function analysis of the species groups using all the characters which were both qualitative (the colour of the fore coxa, the antennae, the wing tuft, the arculus, the ninth abdominal tergite setae and the scutellar setae) and quantitative (the lengths of thorax, antenna, and femur, tibia and first basitarsus of both the fore and hind legs) in nature. The second sought colour characters unique to the S. damnosum subcomplex and to S. yahense, to separate them from the rest, and progressively applied discriminant analyses in the dichotomous stepwise manner to within the subcomplex level. The combination of pale arculus and pale antennae with pale or dark fore coxae were unique to the S. damnosum subcomplex, whilst those of black arculus together with wholly dark or mixed ninth abdominal tergite setae and scutellar setae were unique to S. yahense. Further discrimination was achieved between subcomplexes and species by entering the qualitative and quantitative characters into discriminant function analysis. The two schemes were both successful at separating the main species subcomplexes of the S. damnosum complex, with 90-100% correct classification. Within the subcomplex level, correct identification of sibling species was 85-100% successful.(ABSTRACT TRUNCATED AT 250 WORDS)
Head injuries in children are frequently preventable. These injuries are usually the result of bicycle or motor vehicle accidents, abuse, or gun shot wounds. Maintenance of airway, breathing, and circulation immediately after the initial event may protect against ongoing cerebral damage. Despite these best efforts, brain injury often worsens after the initial insult (so called secondary brain injury). The pathophysiology of head injury has been more clearly delineated as a result of clinical and basic science research. It is still impossible to accurately predict, at the time of presentation, who will have a good and who will have a bad outcome. The focus of initial treatment is based on a sound understanding of cerebral pathophysiology, which is reviewed in this article. Maintenance of adequate cerebral blood flow and metabolism can be monitored by intracranial pressure monitors, jugular bulb catheter data, as well as noninvasive blood flow measurements. In the future, more specific pharmacologic agents will be available to prevent the sequence of events leading to secondary brain injury. A multidisciplinary approach to the treatment of the patients throughout their hospital and posthospital course is described. The hope is that early intervention and aggressive treatment will lead to improved outcome for children suffering head injury.
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Previous studies on the morphological identification of adult female Simulium damnosum s.l. have involved use of colour characters. To determine the degree to which these qualitative characters are influenced by the physical environment, a portable rearing system was constructed. Wild-caught female flies and flies emerging from pupae maintained at ambient temperatures or above showed entirely pale antennae, fore-coxae, wing-tufts and hairs on the scutellum and ninth abdominal tergite, as is normal for S. sirbanum. Adults reared from larvae at below ambient temperatures were also pale, except for the antennae which were dark in all specimens. Adult females emerging from pupae maintained at below ambient temperatures were entirely pale up to the fourth day of emergence and mostly with dark antennae. The biological significance and the implications to the morphological identification of the savannah species of the S. damnosum complex in West Africa are discussed.
This report describes the case of a 32-year-old female with chronic pelvic pain who was otherwise in good health. Endocervical curettings contained rare cells with intranuclear and cytoplasmic inclusions characteristic of cytomegalovirus (CMV) infection. Endometrial curettings demonstrated a stromal lymphocytic and plasmacytic infiltrate as well as numerous small, non-necrotizing granulomas, but no CMV by microscopic examination. However, CMV was identified by the polymerase chain reaction in DNA extracted from a paraffin section of the endometrial tissue. In conjunction with previous reports, the clinical and pathologic features of this case suggest that CMV can cause chronic endometritis in nonimmunocompromised patients. Furthermore, CMV infection should be considered in the differential diagnosis of granulomatous endometritis. This case demonstrates the usefulness of using the polymerase chain reaction to detect CMV in paraffin-embedded material.
Using a simplified procedure, we have extracted DNA from unstained paraffin sections of needle biopsies of kidney and liver transplants and identified the presence of CMV using the polymerase chain reaction. This method utilizes oligonucleotide primers for two genes shown to be specific for cytomegalovirus (CMV) as well as an internal control gene (hemoglobin) in a single reaction. Utilizing nested PCR amplification with agarose gel electrophoresis, CMV can be detected without radioisotopes to a level of sensitivity equivalent to one one-hundredth of a cytomegalic virocyte per cm2 of a 3-microM paraffin section. This method is applicable to situations where only scarce paraffin-embedded tissue is available.
This study examines attitudes and factors affecting the decisions of pediatrics residents of both sexes toward having children during their residencies. In 1987, the authors surveyed by mail all 742 pediatricians who had trained at eight university-based residencies from 1981 to 1987; 417 responded. Of these, the men were significantly more likely than the women to have had children during their residencies (p less than .001). At the time of their residencies, 265 of these pediatricians were married. Of those who were married but did not have children during their residencies (175), the women were significantly more likely than the men to believe that having a child during residency would have had a negative influence on their careers (p less than .001) and would have been associated with difficulties in arranging child care (p less than .001). By contrast, among those pediatricians who were married and did have children during their residencies (90), their perceptions concerning the impacts on their careers of having children and the difficulty in arranging child care did not differ significantly by gender. The authors suggest that programs might explore the possibilities of greater flexibility in scheduling and of making child care more available so that residents could more easily combine their careers with having children.
Hypertension and renal disease are major causes of morbidity and mortality in the diabetic population, with the presence of microalbuminuria established as a predictor of excess mortality. Numerous attempts, both pharmacologic and nonpharmacologic, have been made to intervene in the disease process. Experimental and clinical evidence suggests that the converting enzyme inhibitors and, more recently, certain calcium antagonists have beneficial effects on renal function above and beyond those simply due to blood pressure control. These effects are likely attributable to favorable systemic and renal hemodynamic changes as well as to direct cellular effects. However, intervention with these agents in various rat models of diabetes or hypertension is initiated very early. Hence, some of the beneficial renal effects may not be as dramatic in clinical practice because of the more commonly advanced stage seen at the time of intervention. We present an overview of the histologic, renal hemodynamic, and antiproteinuric effects of these agents in the experimental setting, as well as the clinical evidence supporting the use of angiotensin-converting enzyme inhibitors and certain classes of calcium antagonists in diabetic renal disease.
Since vector control began in 1975, waves of Simulium sirbanum and S. damnosum s.str., the principal vectors of severe blinding onchocerciasis in the West African savannas, have reinvaded treated rivers inside the original boundaries of the Onchocerciasis Control Programme in West Africa. Larviciding of potential source breeding sites has shown that these 'savanna' species are capable of travelling and carrying Onchocerca infection for at least 500 km northeastwards with the monsoon winds in the early rainy season. Vector control has, therefore, been extended progressively westwards. In 1984 the Programme embarked on a major western extension into Guinea, Sierra Leone, western Mali, Senegal and Guinea-Bissau. The transmission resulting from the reinvasion of northern Côte d'Ivoire and Burkina Faso has been reduced by over 95%, but eastern Mali has proved more difficult to protect because of sources in both Guinea and Sierra Leone. Rivers in Sierra Leone were treated for the first time in 1989 and biting and transmission rates in Sierra Leone and Guinea fell by over 90%. Because of treatment problems in some complex rapids and mountainous areas, flies still reinvaded Mali, though biting rates were approximately 70% lower than those recorded before anti-reinvasion treatments started. It was concluded that transmission in eastern Mali has now been reduced to the levels required to control onchocerciasis.
This study defines the variables that predict rehospitalization of infants born to teen mothers. Rehospitalization was defined as hospital admission during the first year of life subsequent to hospitalization at birth. Normal birth weight (NBW), but not low birth weight (LBW), infants of adolescent mothers had higher rehospitalization rates than infants of older mothers. NBW infants of young vs. older mothers had significantly higher rehospitalization rates for gastroenteritis. Among infants of adolescent mothers, the variables associated with increased risk of rehospitalization were unemployed household head, presence of a congenital anomaly or developmental delay, and an unusually high or low number of well child care visits. Although individual variables were significant at the bivariate level, in combination, these variables were poor predictors of which infants would be rehospitalized. Our study suggests that all teen mothers of NBW infants may require additional education to prevent excess rehospitalization of their infants.
Three dietary studies using male Sprague-Dawley rats conditioned to meal-eat a high glucose, fat-free diet and one in vitro study with isolated rat hepatocytes were designed to examine the hypothesis that polyunsaturated fats (i.e., safflower oil or linoleate) are more potent acute inhibitors of liver fatty acid synthesis than are saturated fats (i.e., beef tallow or palmitate). Fat in the first in vivo study was administered via intubation (1500 mg/rat) whereas in the second and third in vivo studies fat was added to the meal in amounts of 50, 100, 250 or 500 mg/g fat-free diet. When the rats were in a postprandial condition, significant suppression of hepatic lipogenesis required the meal to contain 38% of its energy as fat (i.e., 250 mg/g fat-free diet). At this level of fat, safflower oil was more inhibitory than beef tallow (p less than 0.05). The inhibition constant (Ki) for palmitate inhibition of fatty acid synthesis by isolated hepatocytes was fourfold greater than linoleate's Ki (fatty acid/albumin ratio of 1.4/1). When fat constituted 50% of the ingested energy, beef tallow was equivalent to safflower oil as an inhibitor of lipogenesis. Although a single meal containing 50 mg safflower oil/g fat-free diet did not decrease fatty acid synthesis, it effectively delayed the induction of lipogenesis during the first 30 min of the adaptive decrease in lipogenic enzymes attributed to polyunsaturated fats extends to short-term regulatory mechanisms.
African green monkeys were fed diets containing either 11% (by weight) fish oil or lard for 2.5 yr. To test the hypothesis that fish oil decreases hepatic secretion of triglyceride (TG) and apoB, livers from these animals were perfused with a fatty acid mixture [85% (w/w) oleate containing [14C]oleate and 15% n-3 containing [3H]eicosapentaenoic acid (EPA)] at a rate of 0.1 mumol fatty acid/min per g liver. Liver perfusate was sampled every 30 min during 4 h of recirculating perfusion. The concentration of triglyceride was similar for livers of animals of both groups and there was no difference between groups in the extent of incorporation of [3H]EPA or [14C]oleate into hepatic TG. While the secretion rate for the mass of TG was less in the fish oil-fed group (8.3 +/- 2.5 vs 18.3 +/- 4.4 mg/h per 100 g liver, P less than 0.05), the apoB secretion rate was similar (0.92 +/- 0.15 vs 1.01 +/- 0.13 mg/h per 100 g liver). Significantly less [3H]EPA was incorporated into secreted TG in the fish oil group (0.4 +/- 0.1 vs 1.0 +/- 0.1% infused dose/h; P less than 0.01). The rate of secretion of [14C]TG was similar for both groups (1.3 +/- 0.3 vs 1.4 +/- 0.1% infused dose/h for fish oil and lard groups, respectively). No significant diet-related differences in [3H]TG or [14C]TG fatty acid specific activity were observed for perfusate TG or hepatic TG. After perfusion, livers from fish oil-fed monkeys contained significantly more [3H]EPA in hepatic phospholipid than livers from lard-fed monkeys (19.5 +/- 1.8 vs 11.4 +/- 1.7% infused dose; P less than 0.01) although hepatic phospholipid mass concentrations were similar. The liver phospholipids of the fish oil group were enriched in n-3 fatty acid mass and were relatively depleted of oleate and linoleate. We conclude that although apoB secretion was unaffected, dietary fish oil significantly decreased hepatic TG secretion through relatively poor utilization of EPA for the synthesis of TG destined for secretion in VLDL; at the same time, increased incorporation of [3H]EPA into hepatic phospholipid accompanied the decreased incorporation into secreted TG and these events may be coupled.(ABSTRACT TRUNCATED AT 400 WORDS)