Tobacco use and other risk behaviors among adolescents in an STD clinic

OBJECTIVE: To test efficacy of murine monoclonal, rabbit polyclonal recombinant equine or human tumor necrosis factor-alpha (rETNF or rHTNF, respectively) antibodies to inhibit native equine tumor necrosis factor (TNF) activity. ANIMALS: 8 and 18 healthy adult horses for parts 1 and 2 of the study, respectively. PROCEDURES: In part 1, supernates from endotoxin-activated peritoneal macrophages were incubated with various dilutions of each rETNF antibody and subsequently tested for TNF activity. Serum was also obtained from a horse 1 hour after infusion with 20 ng of endotoxin/kg of body weight and was incubated with various dilutions of rabbit polyclonal rHTNF antibody. In part 2, 20 ng of endotoxin/kg was infused in horses during a 30-minute period. Fifteen minutes after the endotoxin infusion was initiated, 1 of 3 preparations was infused: 0.1 mg of rabbit polyclonal (rHTNF antibody/kg, 0.1 mg of human IgG/kg, or 500 ml of 5% dextrose. Clinical and hematologic data were collected for 24 hours. RESULTS: Compared with the monoclonal antibody, the rabbit polyclonal rETNF antibody was more effective in inhibiting TNF activity. The 50% effective doses of the murine monoclonal rETNF, rabbit polyclonal rETNF, and rabbit rHTNF antibodies were 1.8, 0.8, and 0.6 micrograms of antibody/ml, respectively. In part 2, endotoxin infusion resulted in significant alternations in all variables; however, differences among treatment groups were not significant. CONCLUSIONS AND CLINICAL RELEVANCE: Although murine monoclonal and rabbit polyclonal rETNF or rHTNF antibodies are capable of inhibiting native equine TNF activity in vitro, when given after initiation of endotoxemia, administration of 0.1 mg of rabbit polyclonal rHTNF/kg does not alter the response to infusion of endotoxin.     

Effect of percutaneous ethanol injection therapy versus suppressive doses of L-thyroxine on benign solitary solid cold thyroid nodules: a randomized trial

The results of studies using suppressive doses of L-T4 on benign solitary solid cold thyroid nodules have been conflicting. Recently, intranodular injection of absolute ethanol has been proposed as an effective treatment, but has been evaluated only in uncontrolled studies. Our objective was to evaluate the effect of two alternative medical treatment modalities, percutaneous ethanol injection therapy and L-T4, on the benign solitary solid cold thyroid nodule. In a prospective randomized clinical trial, 50 euthyroid patients with a single solid colloid thyroid nodule causing local discomfort were assigned to a single intranodular injection of sterile 98% ethanol (n = 25) or suppressive doses of L-T4 (n = 25). We aimed at an ethanol dose of 20-50% of the pretreatment nodular volume. The initial daily dose of L-T4 was 1.5 microg/kg BW and was adjusted monthly during the first 6 months to reduce serum TSH to subnormal levels (<0.40 mU/L). Thyroid nodule volume and total thyroid volume were assessed by ultrasound, and thyroid function was determined by routine assays before and during follow-up. Symptom scores before and at 12 months were evaluated by a questionnaire rating pressure symptoms and cosmetic symptoms. The median ethanol dose given was 21% [95% confidence interval (CI), 18;25] of the pretreatment nodule volume. In this group, the median reduction in nodule volume was 47% (CI, 33;57; P < 0.0001) compared to 9% (CI, -7;22; P = 0.09) in the L-T4 group. The difference between the two treatment regimens was statistically significant (P < 0.0001). The median reduction in perinodular thyroid volume was 20% (CI, 11;31; P = 0.03) in the L-T4 group, whereas no change was seen in the ethanol group (-2.5%; CI, -18;11; P = 0.9). Fourteen of 25 (56%) patients treated with ethanol injection and 8 of 25 (32%) treated with L-T4 had complete relief of symptoms at 12 months of follow-up (P = 0.09). No major side-effects were seen in either group. Percutaneous ethanol injection therapy administered as a single small dose results in a satisfactory clinical response in approximately 50% of patients by halving the nodule volume. The thyroid nodule-reducing effect of L-T4 suppressive therapy is insignificant, but a subjective satisfactory clinical response is seen in a subgroup of patients, probably explained by the concomitant reduction of perinodular thyroid volume.     

Pregnancy rates for embryos transferred from early postpartum beef cows into recipients with normal estrous cycles

Survival rate of embryos from first ovulations of postpartum cows with SHORT (6.9 +/- 0.3 days; n = 35) or NORMAL (17.1 +/- 0.3 days; n = 42) luteal phases and quality of the embryos on Day 6 were compared. At 19 to 23 days postpartum, cows were allotted to receive a norgestomet implant for 9 days (normal luteal phase) or to serve as untreated controls (short luteal phase). Calves were weaned 7 days after initiation of treatment to induce behavioral estrus in cows for mating. In 25 cows, growth of the ovulatory follicle was monitored by ultrasonography. On Day 6 after estrus, embryos were recovered nonsurgically, and live embryos were transferred into recipient cows exhibiting normal estrous cycles. The medium used to flush the embryos from the uterus of each donor cow was assayed for prostaglandin F2 alpha (PGF2 alpha). Days from calf removal to estrus and size of ovulatory follicles at ovulation (4.1 +/- 0.3 days and 16.7 +/- 0.7 mm, respectively) did not differ between NORMAL and SHORT cows. Interval from detection of the ovulatory follicle to ovulation was longer in NORMAL (10 +/- 0.7 days) than in SHORT cows (8 +/- 0.6 days; p < 0.05). Rates of recovery of an embryo or ovum (64%), rates of fertilization (65%), and quality or stage of development of Day 6 embryos did not differ between SHORT and NORMAL cows. Overall pregnancy rate from recovered oocytes was 13% for SHORT and 32% for NORMAL cows (p = 0.06); survival of fertilized oocytes was 23% for SHORT and 47% for NORMAL cows (p = 0.08).(ABSTRACT TRUNCATED AT 250 WORDS)     

Mechanism of catecholamine-induced proliferation of vascular smooth muscle cells

BACKGROUND: Catecholamines have been shown to aggravate atherosclerosis in animals and humans, and abnormal proliferation of vascular smooth muscle cells (VSMC) is a key event in the early stage of atherosclerosis. Catecholamines may be involved in such cell growth. Therefore, a series of experiments using cultured VSMC was performed to elucidate their possible mitogenic effect. METHODS AND RESULTS: We examined the mitogenic effect of catecholamines using rat aortic smooth muscle cells (VSMC) by measuring [3H]thymidine incorporation, checking with flow cytometry, and counting the cell number directly. Furthermore, the catecholamine-activated signal transduction pathway was assessed by measurement of the formation of inositol 1, 4, 5-triphosphate, intracellular Ca2+ concentration, mitogen-activated protein kinase (MAPK) activity, and mitogenic gene expression. Norepinephrine (NE) and phenylephrine stimulated [3H]thymidine incorporation and cell growth. Clonidine and isoproterenol showed little of such effects. Prazosin was more effective than either yohimbine or propranolol in suppressing the mitogenic effect of NE, indicating that catecholamine-induced VSMC proliferation is mediated by alpha 1-adrenoceptors. The alpha 1-adrenoceptor activation was coupled to pertussis toxin-insensitive Gq-protein and triggered phosphoinositide hydrolysis with subsequent activation of protein kinase C and MAPK in VSMC. In response to NE, both 42- and 44-kD MAPK were activated and tyrosine was phosphorylated. alpha 1-Adrenoceptor stimulation with NE also caused accumulation of c-fos, c-jun, and c-myc mRNA. Chloroethylclonidine completely blocked the alpha 1-adrenoceptor-mediated mitogenesis. CONCLUSIONS: The effect of catecholamines appears to be mediated via the activation of the chloroethylclonidine-sensitive alpha 1-adrenoceptors that triggers the phosphoinositide hydrolysis and activates the MAPK pathway, leading to DNA synthesis and cell proliferation.     

Vein harvest ischemia: a peripheral vascular complication of coronary artery bypass grafting

Lower-extremity ischemia can lead to impaired healing of saphenous vein excision sites in patients with significant peripheral vascular disease (PVD). Five patients who required infrainguinal revascularization for wound necrosis of the harvest site after coronary artery bypass grafting are described. The male/female ratio was 2:3 with a mean age of 67 (range 45-87) years. The most commonly associated problems were insulin-dependent diabetes mellitus (80%) and congestive heart failure (60%). The saphenous vein was harvested from the thigh and leg in three patients and exclusively from the leg in the others. Manifestations of ischemia ranged from persistent ulceration to complete wound disruption threatening limb loss. Impaired healing was isolated to infragenicular wounds in all patients. Pedal pulses were not detected in any of the affected extremities. Determination of the ankle/brachial pressure indices (ABI) revealed values of < 0.5 in three affected limbs. Non-compressible vessels resulted in falsely raised ABI of > 1.0 in the remaining two limbs; however, Doppler waveform analysis in these patients demonstrated significant PVD. Aggressive wound care and antibiotic therapy were continued for mean of 9 weeks before operative intervention. Infrainguinal reconstruction included femoropopliteal (two), femorotibial (two) and popliteal-tibial bypass (one). Autologous arm and saphenous veins in addition to expanded polytetrafluoroethylene grafts were used effectively. Limb salvage and wound healing were achieved in 100% of the patients without untoward sequelae. It is concluded that unrecognized PVD in patients undergoing coronary artery bypass grafting can lead to significant morbidity. Patients at risk may be identified with a combination of history, physical examination and non-invasive testing.(ABSTRACT TRUNCATED AT 250 WORDS)     

The laminar organization of the afferent connections of the cortical column in field 17 in the cat

The laminar structure of the cortical column connections in area 17 of the cat was studied using the microiontophoretic injection of the horseradish peroxidase. Following the enzyme injection in one column at different depths below the cortical surface the identification of morphological types of labelled neurons and the estimation of their localization were performed. When enzyme has been delivered in the whole depth of the column pyramidal neurons labelled were found in upper (I/III) and lower (V/VI) layers (ratio II;I). When the depth of enzyme injection exceeded the cortex width the cells in layer IV were labelled as well. The ratio between the quantity of cells labelled in upper and lower layers was preserved. (II; I). After the enzyme injection in the upper part of the column labelled cells were found mainly in the upper layers. It is concluded that the neurons of the column of have extensive (up to 5 mm), predominantly horizontal afferent connections with the cells in upper and lower layers while the connections with neurons in layer IV are local and do not extend beyond 0.5 mm.     

Potential role of TGF-beta in diabetic nephropathy

Renal injury in diabetes mellitus is a major cause of morbidity and mortality. Several manifestations of diabetic nephropathy may be a consequence of altered production and/or response to cytokines or growth factors. Transforming growth factor-beta (TGF-beta) is one such factor because it promotes renal cell hypertrophy and regulates the production of extracellular matrix molecules. In addition, high ambient glucose increases TGF-beta1 mRNA and protein level in cultured proximal tubular cells and glomerular epithelial and mesangial cells. Neutralizing anti-TGF-beta antibodies or antisense TGF-beta1 oligodeoxynucleotides prevents the hypertrophic effects of high glucose and the stimulation of matrix synthesis in renal cells. Several reports have described overexpression of TGF-beta in the glomeruli and tubulointerstitium of experimental and human diabetes mellitus. We recently provided evidence that the kidney in diabetic patients displays net renal production of immunoreactive TGF-beta1, whereas there is net renal extraction in nondiabetic subjects. We also demonstrated that short-term treatment of streptozotocin-diabetic mice with neutralizing monoclonal antibody directed against TGF-beta significantly reduces kidney weight and glomerular hypertrophy, and attenuates the increase in extracellular matrix mRNA levels. The factors that mediate increased renal TGF-beta activity involve hyperglycemia per se and the intermediary action of other potent mediators such as angiotensin II, thromboxane, endothelins, and platelet-derived growth factor.     

Oligomerization is an intrinsic property of calsequestrin in normal and transformed skeletal muscle

In skeletal muscle fibers, the high-capacity medium-affinity Ca(2+)-binding protein calsequestrin functions as the major Ca(2+)-reservoir of the sarcoplasmic reticulum. To determine the oligomeric status of calsequestrin, immunoblotting of microsomal proteins following chemical crosslinking was performed. Diagonal non-reducing/reducing two-dimensional gel electrophoresis was employed to unequivocally differentiate between cross-linked species of 63 kDa calsequestrin and calsequestrin-like proteins of higher relative molecular mass. Since chronic low-frequency stimulation has a profound effect on the expression of many muscle-specific protein isoforms, we investigated normal and conditioned muscle fibers. Calsequestrin was found to exist in a wide range of high-molecular-mass clusters in normal and chronically stimulated skeletal muscle fibers. Hence, oligomerization is an intrinsic property of this important Ca(2+)-binding protein and does not appear to be influenced by the fast-to-slow transformation process. Although fiber-type specific differences exist in the physiology of the skeletal muscle Ca(2+)-regulatory system, oligomerization of calsequestrin seems to be essential for proper functioning.