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Biomedical subjects

J T Wright

Publications and source records attributed to J T Wright.

At least 145 records · Page 8Linked to original sources
PubMed1990

Opioid modulation of LH secretion by pig pituitary cells in vitro.

The effects of naloxone and beta-endorphin on LH secretion by pig pituitary cells were studied in primary cultures. On Day 4 of culture, cells (10(5) seeded/well) were challenged with 10(-9), 10(-8) or 10(-7) M gonadotrophin-releasing hormone (GnRH), 10(-10), 10(-9), 10(-8) or 10(-7) M-beta-endorphin or 10(-6) M-naloxone individually or in combinations. Secreted LH was measured at 4 h and 24 h after treatment and cellular content of LH was measured after 24 h. Basal LH secretion (control) was 23.5 +/- 7.6 and 36.9 +/- 10.3 ng/well at 4 h and 24 h, respectively. Relative to control at 4 h, 10(-9), 10(-8) or 10(-7) M-GnRH stimulated (P less than 0.05) LH secretion 140%, 210% and 250%, respectively. At 24 h, LH secretion was increased (P less than 0.05) by GnRH compared to control, but the dose-response to GnRH was absent. Naloxone increased (P less than 0.01) LH secretion 166 +/- 13% at 4 h and 141 +/- 13% (P less than 0.06) at 24 h. Secretion of LH after simultaneous addition of 10(-8) M-GnRH plus naloxone was greater (P less than 0.01) than after GnRH alone at 4 h but not at 24 h. beta-Endorphin at 10(-10), 10(-9), 10(-8) or 10(-7) M failed to alter basal LH secretion at 4 h but decreased secretion at 24 h, while cellular LH content was similar to control at 24 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Adipose tissue development in the fetal pig examined using monoclonal antibodies.

Two anti-adipocyte monoclonal antibodies (MAbs: AD-1 and AD-2) have been used to study the development of dorsal s.c. adipose tissue in fetuses from 50 to 110 d of gestation. Immunofluorescent staining of cryostat sections with each antibody revealed antigen-positive cells in fetal s.c. mesenchyme prior to lipid deposition. Lipid droplets as well as AD-1 and AD-2 positive cells were detected within the underlying muscle at 50 d. From 70 to 110 d of development, the AD-1 and AD-2 MAbs each detected all adipocytes examined, as well as capillaries associated with fat cell clusters in s.c. tissues. Reactivity toward both antibodies, as well as lipid deposition, also was detectable in the muscle underlying the s.c. mesenchyme from 70 d onward. Each MAb possessed a distinct pattern of reactivity. The AD-2 MAb stained arrector pili muscles and vessels in the s.c. mesenchyme and vessels in the underlying muscles, whereas the AD-1 did not. No reactivity using either MAb was detectable toward any other cell types within s.c. tissues. These results established the presence of cells expressing surface determinants found on mature adipocytes and associated capillaries prior to adipogenesis. A lineage relationship between adipocytes and capillary endothelial cells is suggested.

Adipose Tissue↗
PubMed1990

Monoclonal antibodies against cell surface antigens expressed during porcine adipocyte differentiation.

Two monoclonal antibodies (AD-1 and AD-2) were prepared by fusion of mouse myeloma cells and lymph node cells of mice immunized with porcine adipocyte plasma membranes. Immunoprecipitation of iodinated adipocyte plasma membrane proteins followed by SDS-PAGE and autoradiography yielded protein antigens for each antibody. The AD-1 and AD-2 antigens were detected on mature adipocytes and a proportion of non-lipid-containing cells in stromal-vascular cultures. Adipocytes and associated capillary networks in subcutaneous adipose tissues as well as capillaries between the underlying muscle fiber bundles bound each antibody, whereas the AD-2 monoclonal antibody also reacted with vessels but not capillaries in liver tissues. In stromal-vascular cell cultures prepared from newborn pig subcutaneous tissue, the AD-1 and AD-2 antibodies exhibited reactivity towards 45 percent and 10 percent respectively, of cells 24 hours after seeding. On the other hand, only 4 percent and 1 percent of the cells in cultures prepared from 60 day fetal subcutaneous tissues expressed detectable amounts of the AD-1 and AD-2 antigens, respectively. In conclusion, cells along the adipogenic lineage possess cell surface antigens which may not be unique to adipogenic cells, but do exhibit differential expression among cell populations within adipose tissues. A temporal relationship between adipogenesis and angiogenesis was also demonstrated.

Adipose Tissue↗
PubMed1989

The effect of high-dose short-term ibuprofen on antihypertensive control with hydrochlorothiazide.

The effect of high-dose ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID), on the blood pressure of treated hypertensive patients was evaluated in a randomized, placebo-controlled, double-blind, crossover trial with 24-hour ambulatory blood pressure monitoring. Twelve middle-aged black women with essential hypertension, controlled with 50 mg hydrochlorothiazide per day, randomly received 3200 mg ibuprofen and a placebo for 8 days. Each treatment phase was separated by a 1-week washout period. Ambulatory blood pressure monitoring (ABPM), body weight, and 24-hour urinary excretion of sodium, creatinine, and prostaglandin E2 (PGE2) were determined at the end of each treatment phase. Mean (+/- SEM) 24-hour systolic and diastolic blood pressures were 122/85 (+/- 2.9/1.7) and 125/85 (+/- 3.0/1.1) during the placebo and ibuprofen phases, respectively. Mean ABPM during six consecutive 4-hour periods also revealed no significant differences between placebo and ibuprofen. We conclude that 3200 mg ibuprofen per day for up to 1 week induced little change in blood pressure in hypertensive who are receiving hydrochlorothiazide.

Adult↗
PubMed1989

Alteration of enamel proteins in hypomaturation amelogenesis imperfecta.

Amelogenesis imperfecta (AI) is a diverse group of disorders that affects primarily the enamel of teeth through a number of developmental processes. The purpose of this study was to characterize the enamel proteins in normal enamel and in hypomaturation AI enamel. Impacted teeth, which were at similar stages of development, were obtained for analysis from an individual with AI and from normal healthy controls. Evaluation of the amino acid profile and quantity of organic material collected showed that there was an excess of enamel protein material that had an amelogenin-like amino acid profile in mature hypomaturation AI enamel. The AI enamel protein content was 5%, while the control enamel had 0.1% protein (by weight). These findings indicate that the maturation process had been altered in this type of AI, and that maturation did not progress beyond the initial stages of secondary mineralization. Since this disorder is inherited as an autosomal recessive condition, it seems likely that the primary defect involves an abnormality in the mechanism for protein removal in enamel maturation.

Adolescent↗
PubMed1989

Transforming growth factor type beta (TGF-beta) and adipogenesis in pigs.

The present study was performed on s.c. adipose tissue of fetal pigs at 35 to 110 d of gestation to examine the distribution of TGF-beta-positive cells, to localize TGF-beta immunoreactivity at the cellular level using electron microscopy (EM), and to determine the effect of TGF-beta on primary cultures of pig adipose tissue cells. Tissues for EM were fixed and embedded in LR white resin. Sections then were incubated with a polyclonal antibody specific for TGF-beta and TGF-beta was located using 20 nm colloidal gold conjugated second antibody. Tissues were fixed and embedded in paraffin for localization of TGF-beta at the light microscope (LM) level. Tissues were incubated with anti-TGF-beta followed by localization using biotinylated second antibody. Using LM, only a few cells stained positively for TGF-beta within developing blood vessels at 35 d. By 50 d, more TGF-beta-positive cells were associated with forming capillary networks. Between 70 d and 110 d, positively stained adipocytes usually were clustered around blood vessels. Cells surrounding hair follicles stained positive for TGF-beta between 90 to 110 d. Electron microscopy revealed TGF-beta labeling within fat cells. Fibroblasts and endothelial cells did not exhibit TGF-beta immunoreactivity. The addition of TGF-beta to primary cultures of s.c. adipose tissue cells from newborn pigs prevented lipid filling in fat cells. This effect was dose-dependent, with half-maximal inhibition occurring at 3 pM maximum inhibition occurred at 40 pM. These results indicate that TGF-beta may regulate angiogenic activity and lipid filling in s.c. adipose tissue of fetal pigs. Although TGF-beta was present in adipocytes and in cells associated with developing capillary networks, the physiological role of TGF-beta during early adipose tissue development is not known.

Adipose Tissue↗
PubMed1989

Oral trauma in adolescent athletes: a study of mouth protectors.

The purpose of this study was to determine the extent of mouth protector use, as well as the amount and type of oral trauma associated with and without mouth guard wear in adolescent athletes. Coaches' perceptions and regulations involving the use of mouth protectors also were examined. Interviews were collected from 2470 junior and senior high school football players with all oral trauma being documented, regardless of the sport during which the injury occurred. Nine per cent of all players suffered from some form of oral injury while another 3% reported a loss of consciousness. Seventy-five per cent of the injuries occurred while not wearing mouth guards, and of this total 40% occurred during baseball and basketball. Fifty-six per cent of all concussions were suffered while not wearing mouth guards. Despite the ability of mouth protectors to significantly help reduce oral injuries, trauma related to sports is more prevalent than previously reported. This study supports the recommendation of mandatory mouth guards in baseball and basketball.

Adolescent↗
PubMed1988

Profile of systemic hypertension in black patients.

Hypertension extracts a huge toll from the black community in terms of excess morbidity and mortality. The black hypertensive is more likely to die from the disease and to have stroke, end-stage renal disease or heart failure. Furthermore, contrary to previous beliefs, blacks are at least as likely to have coronary artery disease as whites. Although substantial overlap occurs, the black hypertensive is more likely to be volume-expanded, to have a lower plasma renin level, and to be classified, as salt-sensitive than is the white hypertensive. Decreased dietary potassium and calcium intake, altered intra-cellular handling of sodium and calcium, and psychosocial factors have also been implicated in the pathophysiology of hypertension in blacks.

Black People↗
PubMed1988

Isradipine (PN 200-110) versus hydrochlorothiazide in mild to moderate hypertension. A multicenter study.

The effects of 10 weeks of treatment with isradipine (ISRP), a new dihydropyridine Ca antagonist, was evaluated in a prospective, randomized, double-blind, parallel group, hydrochlorothiazide (HCTZ) controlled study in patients with mild to moderate hypertension. Of 98 patients enrolled, 73 completed the study and were deemed valid for efficacy analyses; 36 in the ISRP group and 37 in the HCTZ group. Monotherapy with ISRP significantly (P less than 0.001) decreased (mean +/- SD) sitting systolic blood pressure (BP) from 146 +/- 11 mm Hg to 128 +/- 11 mm Hg and diastolic BP from 100 +/- 4 mm Hg to 83 +/- 5 mm Hg. Heart rate during the plateau period was not significantly different (76 +/- 11 vs 78 +/- 11 bpm) between the ISRP and HCTZ groups. These reductions in BP were comparable to monotherapy with HCTZ. The mean reduction in diastolic BP with ISRP (17 +/- 6 mm Hg) was significantly (P less than 0.05) greater than that with HCTZ (14 +/- 5 mm Hg). The mean doses for ISRP and HCTZ were 12 mg/day and 60 mg/day, respectively. There was no significant difference in frequency of common side effects (headache, nausea, fatigue, dizziness, palpitations) between the two groups. However, transient or intermittent peripheral edema occurred more frequently in ISRP group. Four patients in ISRP group (two due to edema and two due to palpitations) and two patients in HCTZ group (due to poor BP control) were discontinued from the study. Our results indicate that ISRP in doses of 5 to 10 mg bid is as effective as HCTZ as monotherapy in the treatment of mild to moderate hypertension.

Blood Pressure↗
PubMed1988

The prevalence of smokeless tobacco use among adolescent male athletes.

In assessing the prevalence and perceptions of use of smokeless tobacco among adolescent male athletes, several findings have public health implications. Almost a third of the sample had tried smokeless tobacco and 8% were current users. Racial differences between blacks and whites were remarkable. Differences in income strata and urban/rural settings were not significant. Peer influence was the major factor that initiated smokeless tobacco use. Abnormal mucosal findings were much more prevalent in those who had dipped smokeless tobacco than in those who had not. Most significant was a prevalence of oral leukoplakia in 5.2% of those who had ever dipped, which was 50 times that of nondippers. Using smokeless tobacco for more than 2 years or using more than three tins per week seemed to be of possible predictive value regarding the incidence of oral leukoplakia. Fifteen percent of current users had observable leukoplakia. Components necessary for effective intervention/prevention programs were elucidated with an emphasis on an increased role by dentists and other health professionals.

Adolescent↗
PubMed1988

Treatment of hypercholesterolemia in black patients.

The treatment of hypercholesterolemia in the black patient will be the next public health challenge facing physicians in the black community. Cost-effective care of hypercholesterolemia will be necessary and is possible, but it will require skill in the use of available therapies, extensive patient education, and excellent communication between patients and health care providers.

Black People↗
PubMed1988

Geriatric hypertension therapy: a guide to cost-effectiveness.

The traditional, stepped-care approach to the treatment of hypertension has been challenged by the introduction of new and more expensive medications. Because hypertensive patients include those who can least afford high-priced medication, such prescribing patterns may result in noncompliance and, further, may cause patients to switch to physicians or managed-care systems more considerate of their economic needs. Physicians should therefore consider cost-effectiveness in treatment of hypertensive patients.

Aged↗
PubMed1987

Effect of high-dose ibuprofen on 24-hour blood pressure in healthy women.

The nonsteroidal antiinflammatory drug (NSAID) indomethacin has been shown to increase blood pressure in normotensive individuals. The effect of other NSAID on blood pressure has not been as well studied. We evaluated the effects of ibuprofen, an NSAID currently available without a prescription, on 24-hour ambulatory blood pressure in ten young, healthy, normotensive women. Using a randomized, crossover, double-blind design, subjects received ibuprofen 800 mg and a placebo identical in appearance to ibuprofen three times a day for eight days with a washout period between regimens. Subjects were instructed to follow a no-added salt diet during the study. Twenty-four-hour blood pressure monitoring and 24-hour urine collection for prostaglandin E2, creatinine, and sodium were performed on days 1 and 8 of each study week. Tablet counts and a 40 percent reduction in urinary prostaglandin E2 documented compliance with ibuprofen. Ibuprofen had no significant effect on systolic or diastolic blood pressure at any hour during the 24-hour period. Mean blood pressure for the 24-hour period was 112/73 and 111/73 mm Hg on day 1 and 111/73 and 112/73 mm Hg on day 8 for placebo and ibuprofen, respectively. We conclude that ibuprofen at doses as high as 2400 mg/d for up to seven days has no effect on blood pressure in normotensive women. Further studies are needed in hypertensive subjects.

Adult↗