Enhanced neutrophil superoxide anion production and its modification by beraprost sodium in spontaneously hypertensive rats.

To clarify the function of polymorphonuclear leukocytes (PMN) in spontaneously hypertensive rats (SHR) and the effect of beraprost sodium (BS) on these functions, we examined superoxide anion (O2-) production and adherent activity by PMN, as well as modification of these functions by BS ex vivo and in vitro. In study 1, we measured PMN functions in 4-week-old SHR and Wistar-Kyoto (WKY) rats. In study 2 (ex vivo), 14-week-old SHR received vehicle (n = 6) and BS (30 microg/kg/day [n = 6] and 100 microg/kg/day [n = 7]) once daily for 4 weeks. In study 3 (in vitro), PMN from 18-week-old SHR were incubated with BS (0.1 and 1 micromol/L) and theophylline (200 micromol/L), which is reported to inhibit the PMN O2- production. Systolic blood pressure, platelet counts, and PMN O2- production stimulated by phorbol ester myristate acetate were significantly elevated in 4-week-old SHR compared with WKY (P < .05). Beraprost sodium decreased the ex vivo PMN O2- production, serum superoxide dismutase activity, and platelet counts (P < .05); however, BS did not reduce the in vitro PMN O2- production. These data support our hypothesis that the enhanced PMN function contributes to the cardiovascular damages during the early phase of SHR, and that BS has merit for preventing the O2- related organ damages in this model.

Furosemide-probenecid interaction as a laboratory exercise for undergraduate education in clinical pharmacology.

OBJECTIVE: The aim of this study was to determine the easiness, reproducibility, and safety of a laboratory exercise for a drug interaction between furosemide and probenecid. METHODS: From 1995 to 1999 approximately 100 medical students participated in the exercise each year after they gave written informed consent. The students were randomly assigned to one of the three groups in a double-blind fashion: group 1, placebo plus 20 mg of furosemide; group 2, 250 mg of probenecid plus 20 mg of furosemide; and group 3, 1000 mg of probenecid plus 20 mg of furosemide. The students took probenecid or its placebo 1 hour before furosemide. Urine volume and urinary sodium excretion were measured for 3 hours after furosemide. At the end of the exercise in 1999, students responded to several questionnaires concerning the utility of furosemide. RESULTS: The entire course of the exercise was completed within half a day. The following findings were obtained every year. (1) Probenecid dose dependently blunted the diuretic effects of furosemide. (2) Time courses of the diuretic effects were altered by probenecid. Ten to twenty percent of the students had slight complaints but completed the exercise without any medications. Finally, more than 80% of the students considered the exercise to be useful. CONCLUSIONS: The data suggest that the exercise of the drug interaction between furosemide and probenecid is easy to perform, reproducible, and safe. Through the experience of the laboratory exercise, students will develop an attitude to assess and estimate potential drug interactions before they prescribe drugs.

[Day surgery for treatment of varicose veins in the leg].

We had surgically treated varicose veins in 554 legs of 386 patients as of June 30, 2000. Varicose veins of the stem or segment type without skin changes were treated with sclerotherapy combined with high ligation, while a part of secondary varicose veins and the reticular or web type were treated with sclerotherapy alone. This paper describes our methods for day surgery for this condition. The most important therapeutic consideration in the surgical procedure is achieving sufficient venous collapse to prevent the occurrence of intravenous thrombus. In our 386 patients, a massive intravenous thrombus that was resected occurred in one limb (0.1%). Postoperative bleeding also occurred in one limb (0.1%) of a patient with severe liver cirrhosis.

Failure of probucol to prolong survival in salt-loaded stroke-prone spontaneously hypertensive rats.

We examined the effect of probucol, a lipid-lowering agent with strong antioxidant properties, on neurological events and survival in stroke-prone spontaneously hypertensive rats (SHRSP). Rapid onset of stroke was induced by maintaining the animals on 1% NaCl solution in place of drinking water. Probucol (10 or 30 mg/kg/day), both of which doses are therapeutic in humans was given by gastric gavage once daily to salt-loaded SHRSP. Animals receiving vehicle were used as controls. Probucol did not influence the elevation of blood pressure. Although probucol did not improve the survival rate of salt-loaded SHRSP, 30 mg/ kg/day of probucol slightly but significantly delayed the development of neurological events (p=0.0235 by generalized Wilcoxon test). However, a high dose of probucol (100 mg/kg/day) did not change the survival or neurological events of salt-loaded SHRSP. These results suggest that probucol may be protective against the development of neurological events, but is not preventive for the progression of stroke in SHRSP.

Polymorphonuclear leukocytes (PMNs) functions in SHR, L-NAME- and DOCA/salt-induced hypertensive rats.

OBJECTIVES: To clarify ex-vivo polymorphonuclear leukocytes (PMNs) functions, we examined superoxide anion (O2-) production and adhesion to a plastic plate of isolated PMNs obtained from spontaneously hypertensive rats (SHR/lzm), NG-nitro-L-arginine methyl ester (L-NAME)- and deoxycorticosterone acetate (DOCA)/salt-induced hypertensive rats. DESIGN: Sixteen week-old male SHR/Izm and Wistar-Kyoto rats (WKY/Izm) were used as a model of hypertension and its control, respectively. L-NAME-hypertension was induced by oral administration of 100 mg/kg per day of L-NAME twice daily for 4 weeks using 4-week-old male Wistar rats. DOCA/salt-hypertension was induced by once daily subcutaneous injection of 1 mg DOCA with 1% NaCl drinking water for 2 weeks using 8-week-old male Wistar rats with heminephrectomy. METHODS: Heparinized whole blood was obtained from abdominal aorta. PMNs were isolated by density gradient following dextran sedimentation. A production of superoxide anion (O2-) by PMNs stimulated with phorbol ester myristate acetate (PMA, 100 ng/ml) was determined by a superoxide dismutase (SOD)-inhibitable cytochrome-C reduction method. Adhesion of PMNs was evaluated by their protein content on a plastic plate measured by Lowry method. RESULTS: SHR/Izm showed a significant enhancement of O2- production by isolated PMNs compared with WKY/Izm. Rats treated with L-NAME showed a lower O2- production by PMNs compared to control animals. In DOCA/salt hypertensive rats, O2- production was not different from that in the control rats. Adherent function of isolated PMNs did not differ significantly among these hypertensive animal models. CONCLUSIONS: These results suggest that O2- production by circulatory PMNs is augmented in SHR, but not in L-NAME and DOCA/salt hypertensive rats. This enhanced function, which is also observed in human essential hypertension, might contribute to the development of cardiovascular damage in genetically determined hypertension.

The functions of circulatory polymorphonuclear leukocytes in diabetic patients with and without diabetic triopathy.

We determined circulatory polymorphonuclear leukocytes (PMN) functions of superoxide anion production, adhesion and aggregation in 38 type 2 diabetic patients with and without diabetic triopathy. Tumor necrosis factor (TNF)-alpha-stimulated superoxide production and N-formyl-methionyl-leucyl-phenylalanine (FMLP)-stimulated aggregation in diabetic patients with triopathy were significantly greater than those in diabetics without triopathy. The more diabetic complications existed, the more TNF-alpha-stimulated superoxide was produced by PMN. These results suggest that the activated PMN contributes to a progression of diabetic triopathy in type 2 diabetic patients.

Enhanced responsiveness of circulatory neutrophils after cardiopulmonary bypass: increased aggregability and superoxide producing capacity.

Cardiac surgery with cardiopulmonary bypass (CPB) induces a whole body inflammatory response that sometimes leads to postoperative organ dysfunction, and neutrophil activation plays an important role in this reaction. Neutrophil priming has been described as a change in neutrophil status such that neutrophils show enhanced responsiveness to a second activating stimulus. We hypothesized that neutrophil priming occurs by cardiac surgery with CPB and is temporally related to the neutrophilia after surgery. To evaluate primed circulatory neutrophil status, we measured aggregation activity stimulated by N-formyl-methyl-leucyl-phenyl-alanine (FMLP) and free radical producing activity by tumor necrosing factor (TNF) alpha in peripheral blood samples. Eleven adult patients undergoing elective cardiac surgery with CPB were studied. Blood samples were taken before surgery, at the end of bypass, 12 h after surgery, and 7 days after surgery. Aggregation activity and superoxide generation were significantly elevated 12 h after surgery when compared to presurgery values, indicating that cardiac surgery is associated with circulatory neutrophil priming. The number of neutrophils markedly increased at the end of cardiopulmonary bypass and reached a peak 12 h after surgery. The circulatory neutrophils of cardiac surgical patients become primed after surgery, coincident with the peak neutrophil count. These results suggest that circulatory neutrophils after cardiac surgery with CPB have enhanced responsiveness and are predisposed to systemic inflammation.

Experimental small bowel transplantation using newborn intestine in rats: II. Revascularization of newborn intestine is independent of vascular endothelial growth factor.

BACKGROUND: Fetal and newborn intestine often are revascularized after subcutaneous transplantation without surgical vascular anastomosis. However, the mechanism of this ability remains unclear. METHODS: First, the ability of natural revascularization in newborn organs was tested. Newborn organs in whole (liver, kidney, heart, intestine, spleen, and pancreas) were grafted i nto the subcuta neous tissue of the adult rat and evaluated histopathologically 2 weeks after transplantation. Second, expression of vascular endothelial growth factor (VEGF) mRNA in the intestinal graft was determined before and after transplantation. Finally, we tested whether the free graft survival of newborn intestine was interrupted by TNP-470, an antiangiogenic agent. RESULTS: Spleen and intestine were revascularized at a higher rate (91.6%, 75%, respectively), and kidney and heart grafts survived at a lower rate (41.7%, 25%, respectively). But all of liver and pancreas grafts failed to be revascularized. VEGF mRNA was not induced in the course of revascularizing. Furthermore, TNP-470 did not interfere with neovascularization of the newborn intestinal graft in vivo. CONCLUSIONS: Each organ had an organ-specific angiogenic activity. Neovascularization of intestinal graft was not dependent on VEGF expression.

A comparison of the antagonistic activities of tamsulosin and terazosin against human vascular alpha1-adrenoceptors.

Tamsulosin, a selective alpha1A-adrenoceptor antagonist, and terazosin, a non-selective one, are effective for the treatment of urinary disturbance due to benign prostatic hypertrophy. In the present study, their alpha1-adrenoceptor-blocking effects on blood vessels, which may cause orthostatic hypotension, were investigated in 10 healthy males. After the subjects took orally 0.2 mg of tamsulosin, 1 mg of terazosin or a lactate capsule as the control in a randomized cross-over fashion, their finger tip vasoconstrictor response to cold stimulation and vasoconstrictor response of the dorsal hand vein to increasing doses of phenylephrine were examined. The finger tip vasoconstrictor response was significantly reduced and the infusion rate of phenylephrine producing a half-maximal constriction was significantly increased by terazosin, but tamsulosin had no significant effect on these parameters. These data suggest that the usual dose of tamsulosin exerts little alpha1-adrenoceptor-blocking activity on blood vessels, and orthostatic episodes might be mild, if any, during the treatment with tamsulosin.

Combination effects of tamoxifen plus 5-fluorouracil on gastric cancer cell lines in vitro.

We tested the effect of tamoxifen alone and tamoxifen plus 5-fluorouracil (5-FU) on proliferation of two different types of gastric cancer cell lines using the WST-1 method. A high dose of tamoxifen suppressed the proliferation of KATOIII cells (poorly differentiated adenocarcinoma), but MKN28 cells (well-differentiated adenocarcinoma) were not affected. The combination of the two drugs resulted in a synergistic anti-proliferative activity on KATOIII cells. On the other hand, in the combination therapy, tamoxifen stimulated MKN28 cells to proliferate in a dose-dependent manner. TGF-beta1 secretion was not changed in KATOIII cells by tamoxifen plus 5-FU treatment but was down-regulated in MKN28 cells. Both cancer cell lines were judged as intracellular estrogen receptor (ER) negative. These data suggest that the anti-proliferative effects of tamoxifen plus 5-FU on KATOIII cells were not dependent on ER expression or TGF-beta1 secretion. On the other hand, their proliferative effects on MKN28 cells might be, in part, caused by the reduced secretion of TGF-beta1.

Impaired beta-adrenoceptor mediated venodilation in patients with diabetes mellitus.

AIMS: We investigated whether venoconstriction by alpha-adrenoceptor stimulation, and venodilation by beta-adrenoceptor stimulation and nitroglycerin are altered in patients with diabetes mellitus (DM). METHODS: Eight male patients with non insulin-dependent DM and eight age-matched control subjects were included. The patients had neither hypertension nor hyperlipidaemia. Noradrenaline (1 to 512 ng min-1 ), isoprenaline (1 to 256 ng min-1 ) and nitroglycerin (0.5 to 128 ng min-1 ) were infused into a dorsal hand vein and its diameter was measured using a linear variable differential transformer. RESULTS: The venoconstricting response to noradrenaline and the venodilating response to nitroglycerin in DM patients were similar to those in control subjects, while the venodilation by isoprenaline was significantly (P<0.05) smaller in DM patients than in control subjects at the dose of 32 ng min-1 or more [32 ng min-1: 11.5% vs 29.8% (DM vs control subjects), 64 ng min-1: 19.0% vs 40.1%, 128 ng min-1: 25.2% vs 49.0%, 256 ng min-1: 34.3% vs 56.7%]. CONCLUSIONS: These data suggested that venoconstriction by alpha-adrenoceptor stimulation and venodilation by nitroglycerin are not altered, whereas venodilation by beta-adrenoceptor stimulation might be impaired in patients with DM.

Angiotensin II in human veins: development of rapid desensitization and effect of indomethacin.

1. The present study investigated whether rapid desensitization (tachyphylaxis) develops after exposure of human hand veins to angiotensin (Ang)II and whether pretreatment with indomethacin affects its development. 2. Venoconstrictor responses to increasing (2-256 ng/min) and constant (50 ng/min) doses of AngII and noradrenaline (NA) infusion were obtained in six healthy male subjects using the dorsal hand vein technique. After pretreatment with indomethacin and placebo, venoconstrictor responses to 50 ng/min AngII infusion were obtained in eight healthy male subjects. 3. The maximal mean (+/- SD) venoconstrictor response to NA (obtained with 256 ng/min NA) was 93.1 +/- 4.7%, whereas that to AngII (obtained with doses between 16 and 128 ng/min) was 43.8 +/- 12.2%. Continuous infusion of NA induced constant venoconstriction, whereas the venoconstrictor response to AngII peaked 3 min after the beginning of infusion and, thereafter, was attenuated. 4. Venoconstriction in response to constant AngII infusion after indomethacin pretreatment was significantly larger than that after placebo from 6 to 18 min after the initiation of infusion. 5. These findings show that rapid desensitization to AngII develops in human hand veins and this is compatible with the hypothesis that vasodilator prostaglandins are involved in the development of this desensitization.

Effect of pretreatment with FTY720 and cyclosporin on ischaemia-reperfusion injury of the liver in rats.

The effect of pretreatment with FTY720 (2-amino-2-[2-(4-octylphenyl)ethyl]-1,3-propanediol hydrochloride) or cyclosporin, or both, on neutrophil-mediated injury has been examined by use of a rat model of transient clamping of hepatic flow. Pretreatment with FTY720 alone or with cyclosporin induced a marked reduction of circulatory lymphocytes, whereas the use of these drugs in combination was very effective at suppressing the elevation of the number of peripheral polymorphonuclear neutrophils (PMN) after reperfusion. Pretreatment with cyclosporin, with or without FTY720, significantly reduced hepatic damage, whereas FTY720 alone tended to prolong hepatic damage. Pretreatment of cyclosporin alone, but not in combination with FTY720, significantly reduced the accumulation of PMN and led to lower myeloperoxidase levels in the damaged liver. In conclusion, pretreatment with cyclosporin, with or without FTY720, reduced hepatic damage after warm ischaemia-reperfusion, whereas pretreatment with FTY720 alone tended to prolong this damage.

[A case report of total removal of infected pacemaker leads with cardiopulmonary bypass through right thoracotomy].

A 61-year-old man with septicemia had four infected pacemaker leads, which were impossible to remove using simple traction method. He received CABG previously, and SVG anastomosed to LAD was patent. Redo median sternotomy had a possibility to make damage to SVG. Total removal of infected pacemaker was performed successfully with cardiopulmonary bypass through right thoracotomy.

Huge aneurysm of the sinus of Valsalva following infective endocarditis in Behçet's disease.

A huge aneurysm of the sinus of Valsalva with conduction disturbance as a consequence of infective endocarditis in Behçet's disease is reported. The aneurysm extended not only into the ventricular septum but also to the right atrium and ventricle, with a complicated cavity formation. We speculate that complete atrioventricular block occurred due to an enlargement of the aneurysm into the ventricular septum, leading to a direct conduction system injury. Preoperative echocardiography and aortography were insufficient to recognize the extent of the lesion; subsequent operative examination revealed the true size. At operation, it is important to understand the lesion dimensions fully in order that appropriate surgical procedures be performed.