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S So

Publications and source records attributed to S So.

At least 37 records · Page 2Linked to original sources
PubMed1995

Effects of calcium channel antagonists on the induction of nitric oxide synthase in cultured cells by immunostimulants.

We investigated whether calcium channel antagonists would alter the induction of nitric oxide (NO) synthesis by bacterial lipopolysaccharide (LPS) alone or in combination with interferon-gamma (IFN gamma) in cultured J774 macrophages, rat vascular smooth muscle cells, rat renal mesangial cells, and rat cardiac myocytes. The induction of NO synthesis was determined by measuring nitrite, the stable end-product. The dihydropyridine calcium channel antagonists, nifedipine, manidipine, nitrendipine, benidipine, barnidipine, perdipine, and nilvadipine all reduced the LPS-induced nitrite production in a dose-dependent manner, each with a differing half-maximal inhibitory concentration, in cultured J774 macrophages. Nifedipine also inhibited nitrite production in vascular smooth muscle cells, mesangial cells, and cardiac myocytes. The half-maximal inhibitory concentrations of nifedipine were ranked as follows: smooth muscle cells < mesangial cells < cardiac myocytes. Diltiazem, at nontoxic concentrations, had no effect on the nitrite formation in the three cell types. Verapamil markedly increased the formation of nitrite in cardiac myocytes in response to LPS and IFN gamma, but not in vascular smooth muscle or mesangial cells. Exposure of cardiac myocytes to LPS and IFN gamma caused the expression of NO synthase mRNA that was significantly increased by verapamil. Thus, certain calcium channel antagonists modulate NO synthesis by altering the induction of NO synthase.

Adjuvants, Immunologic↗
PubMed1995

Long-term airway considerations after treatment of severe pediatric laryngotracheal stenosis in five children.

After initial treatment of severe laryngotracheal stenosis (LTS), we evaluated subsequent airway function. Five children between 2 and 11 years were treated previously for severe LTS by T-tube stenting. One case underwent subsequent laryngotracheal reconstruction. All patients demonstrated dyspnea, the severity of which increased with age and duration of time after completion of stenosis treatment. In the most severe cases, magnetic resonance imaging and endoscopy revealed secondary subglottic stenosis. Ventilatory function tests disclosed obstruction of both extrathoracic and pulmonary origin. These findings raise questions regarding the treatment of the initial stenosing tissue and of the secondary stenoses.

Airway Obstruction↗
PubMed1995

Different growth control of the two human thyroid cell lines of adenomatous goiter and papillary carcinoma.

To study the growth control of human thyroid cells in different stages of differentiation, we established two human thyroid cell lines of adenomatous goiter and papillary carcinoma. A 59-year-old female patient with adenomatous goiter was operated in September 1991, and a 27-year-old female patient with papillary carcinoma in May 1990. The thyroid cell lines were established by successive passage without cellular or genetic manipulations such as fusing other cell lines or oncogenic viral infection. These cell lines, human adenomatous goiter cells (hAG) and human papillary thyroid carcinoma cells (hPTC), exhibited a flattened polygonal shape and proliferated as a monolayer in cell culture. The doubling time of the hAG cells was 60 h in Ham's F12 medium supplemented with 10% fetal bovine serum, and that of the hPTC cells, 18 h in the same medium. Both cell lines expressed mRNA for TSH receptor and secreted cAMP into the medium during incubation with thyrotropin (TSH) at concentrations as low as 0.01 mU/mL. The effects of activators of protein kinase A (PKA), protein kinase C (PKC), tyrosine kinase (TK), and estradiol (E2) on proliferation of the hAG cells and the hPTC cells were assessed by measuring cellular DNA content in 24-well plates with diaminobenzoic acid. TSH stimulated proliferation of the hAG cells, but it inhibited proliferation of the hPTC cells. Since TSH activates two signaling pathways, the adenyl cyclase-PKA system and phospholipase C-PKC system, we tested effects of dibutylyl cAMP (dBC) and phorbol myristate 13-acetate (PMA), separately. dBC stimulated proliferation of the hAG cells, but it inhibited that of the hPTC cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1995

Vesnarinone inhibits induction of nitric oxide synthase in J774 macrophages and rat cardiac myocytes in culture.

OBJECTIVE: We investigated whether vesnarinone alters the induction of nitric oxide (NO) synthesis by bacterial lipopolysaccharide (LPS) or in combination with interferon-gamma in cultured J774 macrophages and rat cardiac myocytes. METHODS: The induction of NO synthesis was determined by measuring the stable end-product nitrite. The cytotoxic effect of vesnarinone was assessed by measuring cell respiration. Any change in mRNA levels for NO synthase (NOS) was determined by RT-PCR. RESULTS: Stimulation by LPS or in combination with interferon-gamma increased the accumulation of nitrite in the supernatant of J774 macrophages or cardiac myocytes. NOS induction accounted for this accumulation of nitrite, as dexamethasone, NG-methyl-L-arginine, and cycloheximide each reduced the production of nitrite in both types of cells. Vesnarinone produced a significant decline in the cumulative production of nitrite in both types of cells without evidence of cytotoxicity. However, the addition of vesnarinone after induction of NOS did not inhibit nitrite production. Treatment with LPS or in combination with interferon-gamma led to a significant expression of NOS mRNA in both types of cells that was significantly reduced by vesnarinone. CONCLUSIONS: Vesnarinone inhibited NO synthesis by inhibiting the induction of NOS in J774 macrophages and cardiac myocytes. This drug may exert a beneficial effect in patients with heart failure, in part, by attenuating the production of NO.

Animals↗
PubMed1994

Prevention of rejection and graft loss with an aggressive quadruple immunosuppressive therapy regimen in children and adolescents.

During the two-year period May 1991 to April 1993, 36 kidney transplants were performed in children less than 18 years of age at California Pacific Medical Center using an aggressive quadruple-therapy regimen of immunosuppression. The regimen consisted of induction with an antilymphocyte preparation (MALG in 21, OKT3 in 2, ATGAM in 12, none in 1), initial moderate-dose steroid therapy, early intravenous cyclosporine therapy, and azathioprine. Twenty living-related graft recipients were pretreated with donor-specific transfusions. Long-term cyclosporine was dosed by levels to keep through whole-blood levels (RIA) at 200-300 ng/ml. Twenty-five grafts were from living-related donors, two from living unrelated donors, and nine from cadaveric donors. Eleven (30%) recipients were five years old or under at the time of transplantation. Of these recipients 44% had complex congenital urologic disease and required urologic surgery prior to or at the time of transplantation. Patients have been followed for a mean of one year, with actual patient and graft survivals of 100% and 97%, respectively. Only one graft has been lost, to severe, early recurrent focal segmental glomerulosclerosis. Four of the 36 patients have had one rejection episode each, all reversed completely. Graft function is stable, with serum creatinine proportionate to age--mean serum creatinine in the children under two years old being 0.4 mg/dl, and in the adolescents 1.3 mg/dl, with two adolescent boys having the highest creatinine levels at 1.8 mg/dl. We conclude that an aggressive approach to immunosuppressive therapy in the early posttransplant period with MALG/OKT3/ATGAM induction and rapid achievement of therapeutic cyclosporine levels prevents rejection and results in excellent patient and graft survival with subsequent stable good graft function.

Adolescent↗
PubMed1994

Growth regulation of the human papillary thyroid cancer cell line by protein tyrosine kinase and cAMP-dependent protein kinase.

We established a cell line (hPTC) from the tissue of papillary thyroid cancer surgically excised from a 27-year-old female patient. Synthesis of cAMP by the hPTC cells was stimulated by TSH. This cell line has continued to divide as a monolayer in a tissue culture for three years. We assessed growth regulation of the hPTC cells by protein tyrosine kinase and cAMP-dependent protein kinase by measuring the DNA content of the hPTC cells in 24-well plates with 3,5-diaminobenzoic acid after incubation in various growth factors. Basic fibroblast growth factor (FGF), epidermal growth factor (EGF), and insulin-like growth factor-1 (IGF-1), all of which bind to their respective receptors with tyrosine kinase activity, stimulated DNA synthesis in the hPTC cells. Neutralizing antibodies to basic FGF and EGF suppressed the growth stimulation by basic FGF and EGF, respectively. Genistein, a specific protein tyrosine kinase inhibitor, inhibited proliferation of the hPTC cells. On the other hand, thyrotropin, dibutyryl cAMP (dBC) and forskolin inhibited proliferation. KT5720, a specific cAMP-dependent protein kinase inhibitor, restored the growth of the hPTC cells even in the presence of dBC. This study shows that stimulation of the protein tyrosine kinase activity by basic FGF, EGF, and IGF-1 promoted DNA replication by the human thyroid cancer cell line. However, activation of the cAMP-dependent protein kinase inhibited proliferation of this cell line.

Adult↗
PubMed1993

[An experience with a continent appendix stoma].

The submucosally embedded in situ appendix guarantees an ideal continence mechanism in patients with ileocecal urinary reservoirs. To date this modification of the Mainz pouch technique was performed successfully in 10 patients between September 1990 and October 1992. Pouch capacity ranged from 350 ml to 900 ml (mean: 565 ml), frequency of intermittent self-catheterization ranged from 3 to 7 times per day (mean: 4.4-5.4 times) and complete urinary continence without difficulty of self-catheterization was obtained in eight patients. Two patients with stomal stenosis needed to indwell a catheter. The follow up periods ranged from 3 to 24 months (mean: 14.7 months). The main advantages of appendix stoma technique are shorter operation time, a short ileal segment, no risk of nipple gliding or prolapse, no need for staples, thereby decreasing significantly the risk of stone formation, and facilitating easy catheterization. This method seemed to be valuable for continent urinary reservoir assuring patients of high quality of life.

Adenocarcinoma↗
PubMed1993

[Congenital hypoplasia of the left pulmonary artery and exertion hypoxemia].

The reported case concerns a 12-year-old boy with a congenital hypoplasia of the left pulmonary artery without associated cardiac malformation. At rest, pulmonary function tests were within the normal range, while the patient demonstrated an abnormal dyspnea and hypoxemia during exercise. These symptoms disappeared after left pneumonectomy. Unilateral pulmonary artery hypoplasia can be responsible for exercise hypoxemia due to an intermittent right-to-left shunt or a ventilation-to-perfusion mismatching.

Child↗