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Biomedical subjects

L B Williams

Publications and source records attributed to L B Williams.

At least 19 recordsLinked to original sources
PubMed2000

Hexosamines regulate leptin production in human subcutaneous adipocytes.

The hexosamine biosynthetic pathway has recently been proposed as a mechanism through which cells "sense" nutrient flux to regulate leptin release. This study was undertaken to examine the regulation of leptin production by hexosamines in human adipocytes. Adipose tissue UDP-N-acetylglucosamine, an end product of hexosamine biosynthesis, was elevated 3.2-fold, and ob messenger ribonucleic acid was elevated 2-fold in the sc adipose tissue of 17 obese [body mass index (BMI), 41.3+/-12.0 kg/m2; age, 31+/-5 yr] subjects compared to 14 lean (BMI, 23.4+/-1.6 kg/m2; age, 33+/-11 yr) subjects. Serum leptin was increased 2.7-fold in the obese subjects. A significant positive relationship was found between adipose tissue UDP-N-acetylglucosamine and BMI (Spearman correlation = 0.576; P = 0.0007) and between UDP-N-acetylglucosamine and serum leptin (Spearman correlation = 0.4650; P = 0.0145). Treatment of isolated sc adipocytes with 1 mmol/L glucosamine, an intermediate product in UDP-N-acetylglucosamine biosynthesis, increased leptin release 21.4+/-17.6% (mean +/- SD) over control (P = 0.0365) and 74.5+/-82.8% over control (P = 0.0271) in adipocytes from lean (BMI, 23.2+/-1.6 kg/m2; n = 6) and obese (BMI, 55.4+/-13.0 kg/m2,; n = 9) subjects, respectively, by 48 h of culture. Inhibition of UDP-N-acetylglucosamine biosynthesis with 6-diazo-5-oxo-norleucine reduced glucose-stimulated leptin release from cultured adipocytes 21.8+/-32.4% (P = 0.0395; n = 12) and ob gene expression 19.9+/-18.9% (P = 0.0208; n = 8) by 48 h of treatment. These findings suggest that hexosamine biosynthesis regulates leptin production in human adipose tissue.

Adipocytes↗
PubMed2000

Tumor necrosis factor-alpha inhibits leptin production in subcutaneous and omental adipocytes from morbidly obese humans.

This study was undertaken to examine the regulation of leptin production from human adipocytes by tumor necrosis factor-alpha (TNFalpha). Adipocytes were isolated from adipose tissue obtained during bariatric surgical procedures (17 women and 3 men; body mass index, 52.5 +/- 2.4 kg/m2; age, 40 +/- 3 yr) and cultured in suspension. Leptin release from sc adipocytes was inhibited 17.7 +/- 5.2% (P < 0.01), 21.6 +/- 4.3% (P < 0.005), and 37.1 +/- 7.2% (P < 0.05) by 1, 10, and 100 ng/mL TNFalpha, respectively, after 48 h in culture. At 100 ng/mL, significant inhibition of leptin release (25.8 +/- 9.7%; P < 0.05) was detected by 24 h. TNFalpha (10 ng/mL) had no effect on dexamethasone (0.1 micromol/L)-stimulated leptin production in sc adipocytes. In omental adipocytes TNFalpha inhibited leptin release 21.0 +/- 9.6% and 40.8 +/- 6.3% at 10 and 100 ng/mL by 48 h (P < 0.05). Significant inhibition ofleptin release from omental adipocytes was observed at 24 h with 100 ng/mL TNFalpha (P < 0.05). Anti-TNFalpha antibody completely blocked TNFalpha inhibition of leptin release. The ob messenger ribonucleic acid was significantly reduced (23.6 +/- 5.9%) after 48 h of TNFalpha (100 ng/mL) treatment (P < 0.025). TNFalpha had no effect on glucose uptake or lactate production in sc and omental adipocytes. The data suggest that the direct paracrine effect of adipose-derived TNFalpha is inhibition of leptin production.

Adipocytes↗
PubMed2000

Leptin production in adipocytes from morbidly obese subjects: stimulation by dexamethasone, inhibition with troglitazone, and influence of gender.

This study examined the regulation of leptin production by dexamethasone and troglitazone. Subcutaneous and omental adipose tissue was obtained during bariatric surgical procedures (30 women and 16 men; body mass index, 52.5 +/- 1.7 kg/m2, age, 39 +/- 2 yr), and adipocytes were cultured in suspension. Subcutaneous adipocytes from females released significantly more leptin than did omental cells from the same subject (P < 0.05), but basal leptin release was not different in adipocytes from these depots in males. Dexamethasone (0.1 micromol/L) significantly increased leptin release within 24 h from sc (135 +/- 13% of control) and omental (227 +/- 53%) adipocytes of females, but not males. Dexamethasone-stimulated leptin production at 48 h was significantly greater in the omental adipocytes of females (398 +/- 64% of control) than in sc adipocytes of females (207 +/- 21%) or the omental (211 +/- 33%) and sc (180 +/- 23%) adipocytes of males. Troglitazone (10 micromol/L; 48 h) significantly inhibited dexamethasone-stimulated leptin release in sc (57 +/- 10.7% inhibition) and omental adipocytes (134 +/- 26% inhibition). There was no gender-related difference in the effect of troglitazone to inhibit dexamethasone-stimulated leptin release. Troglitazone significantly inhibited basal leptin production from omental adipocytes by 15.0 +/- 5.2%. The effect of dexamethasone and troglitazone to regulate leptin release was mediated through changes in ob gene expression, but did not involve changes in glucose uptake or metabolism to lactate. The data suggest that adipocytes from females are more responsive to the stimulatory effect of dexamethasone in vitro than are adipocytes from males. If adipocytes from females are more responsive to relevant in vivo stimuli for leptin secretion such as insulin or glucose, this could contribute to the gender difference in serum leptin. The data also suggest that leptin release from omental adipocytes may be more responsive to hormonal and nutrient regulation in vivo than are sc adipocytes.

Adipocytes↗
PubMed1997

Study of mechanical versus manual/mechanical compression following various interventional cardiology procedures.

Knowledge and technology for cardiovascular disease are growing at a rapid rate. Interventional cardiology offers patients several options of therapy, including percutaneous transluminal coronary angioplasty, directional coronary atherectomy, and percutaneous transluminal coronary rotoblator angioplasty procedures. Patients with these procedures require femoral intra-arterial sheath insertion and postprocedure management of these sheaths. The best practice for sheath removal is a controversial issue. This article describes a study conducted at Presbyterian Hospital in Charlotte, North Carolina, comparing the use of manual/mechanical versus mechanical compression technique for sheath removal. Subjects included patients who had one of the previous procedures performed. Subjects were randomly assigned to one of two study groups: manual/ mechanical or mechanical compression. Variables such as size of sheath, anticoagulants, antiplatelets, and flat time after sheath removal were examined. The outcome measure reported was the development of a groin complication. Results indicated no significant difference in groin complication. As a result, practice at Presbyterian Hospital changed to mechanical compression for removing sheaths.

Angioplasty, Balloon, Coronary↗
PubMed1995

High-dose folinic acid and 5-fluorouracil bolus and continuous infusion in advanced colorectal cancer: poor response rate in unselected patients.

We have conducted a retrospective study of high-dose folinic acid and 5-fluorouracil in 96 patients with advanced colorectal cancer. Patients received 200 mg m-2 (maximum 300-350 mg) folinic acid by infusion over 2 h followed by an i.v. bolus of 5-fluorouracil 400 mg m-2 then an infusion of 5-fluorouracil 600 mg m-2 over 22 h. This was repeated over the next 24 h. The schedule was given every 2 weeks for four cycles; thereafter patients with objective response continued to a maximum of eight cycles. The overall response rate was 10.6% in 85 evaluable patients. The median duration of response was 11 months. The median survival was 6 months. Toxicity was low, only one patient experiencing toxicity greater than WHO grade II (grade IV platelet toxicity). Diarrhoea, nausea, vomiting and mucositis also occurred but were mild and infrequent. Our low response rate may be related to factors such as patient characteristics or duration of treatment.

Adult↗
PubMed1992

Silent maladie de Roger.

A patient with no cardiac murmur was found to have a ventricular septal defect by Doppler echocardiography yet no evidence of pulmonary or right ventricular hypertension. This array of findings is distinctly unusual and appears to be at odds with the clinical teachings concerning small ventricular septal defects.

Adult↗
PubMed1992

Religion and fertility in the United States: new patterns.

In the United States, the baby boom-era pattern of high Catholic and low Protestant fertility has ended. Among non-Hispanic whites in the 1980s, Catholic total fertility rates (TFRs) were about one-quarter of a child lower than Protestant rates (1.64 vs. 1.91). Most of the Protestant-Catholic difference is related to later and less frequent marriage among Catholics. Future research on the demography of religious groups should focus on explaining the delayed marriage pattern of Catholics, the high fertility of Mormons and frequently attending Protestants, and the very low fertility of those with no religious affiliation.

Birth Rate↗
PubMed1988

Digenetic trematodes of marine fishes of Okinawa, Japan.

Between May and September 1985, 348 fishes representing 50 families, 107 genera, and 152 species from the coastal waters of Okinawa were examined for digenetic flukes. Ten families (Lepocreadiidae, Opistholebetidae, Gyliauchenidae, Fellodistomidae, Acanthocolpidae, Opecoelidae, Bucephalidae, Cryptogonimidae, Syncoeliidae, and Hemiuridae), representing 29 genera and 34 species of digenetic flukes were recorded. Seven new geographic locality records and 25 new host records were established. Possibly 2 new species, one being a species of the genus Metadena from Meiacanthus grammistes and the other a species of the genus Mesolecitha from Plectorhynchus chaetodontoides, were detected. Most infections were of a single species, and although prevalence and intensity were low, host specificity was high. Only 3 of the 34 species identified transgressed family bounds in their definitive hosts.

Animals↗
PubMed1987

Intractable complex partial seizures: the "initial motionless stare" and surgical outcome following temporal lobectomy.

Complex partial seizures (CPSs) beginning with an initial motionless stare (IMS) have been reported to respond well to temporal lobectomy. CPSs without the IMS or with early lateralizing motor phenomena often persisted after temporal lobectomy. We have studied video-EEG-recorded seizures of 18 patients with depth electrodes who then underwent temporal lobectomy. The IMS did not correlate with success or failure of surgery. However, initial head and/or eye deviation was correlated with poor surgical outcome.

Adolescent↗
PubMed1985

A clinical nurse specialist in a line management position.

The authors describe their experiences utilizing a clinical nurse specialist in a middle management role in an organizational framework to support primary nursing. They describe the original design and planning of the organizational model 12 years ago, the administrative supports that have been added in the intervening years, and how professional and administrative authority are integrated by the clinical nurse specialist in a line position.

Administrative Personnel↗
PubMed1976

Six years of experience with a summer program for minority students.

This artical summarizes six years of experience of the University of Texas Medical Branch at Galveston (UTMB) with a summer program for the recruitment of minority students. During the six years, UTMB conducted six summer experiences for 112 Mexican-American and black premedical students and made numerous contacts with undergraduate college faculty and administrative staff for the purpose of increasing minority student enrollment in medical schools in general and in UTMB in particular. The program, which emphasized experiences which would increase the potential student's motivations, information, and academic skills, has resulted in numerous minority students entering medical school; but the impact on UTMB enrollments has been disappointing. Implications of the results of the program on future efforts to recruit minority students are discussed.

Curriculum↗