Evaluation of pharmacological profile of meloxicam as an anti-inflammatory agent, with particular reference to its relative selectivity for cyclooxygenase-2 over cyclooxygenase-1

We studied the anti-inflammatory activity of meloxicam on rat carrageenin-induced pleurisy and its toxicity for rat gastric mucosa, relative to its in vitro inhibitory potency against partially purified cyclooxygenase (COX)-1 and COX-2 preparations in order to clarify the pharmacological profile of the compound as an anti-inflammatory agent. In rat carrageenin-induced pleurisy, the plasma exudation rate peaked at 5 h, at which time COX-2 was detectable in cells from the pleural exudate. Meloxicam and piroxicam (1 and 3 mg/kg) and NS-398 (3 mg/kg) showed almost equal anti-inflammatory potency against 5-hour pleurisy. A single oral administration of the compounds caused a dose-dependent increase in the number of rats with gastric mucosal erosion. The ED50 value for meloxicam (5.92 mg/kg) was significantly higher than that for piroxicam (1.76 mg/kg), indicating that meloxicam is safer. Indometacin showed intermediate safety (2.59 mg/kg). In in vitro experiments, indometacin inhibited COX-1 about 1.7 times more potently than COX-2. NS-398 inhibited COX-2 with an IC50 of 0.32 microM, but never affected COX-1 activity, even at 100 microM. In the same assay system, meloxicam inhibited COX-2 about 12 times more selectively than COX-1. Piroxicam, however, inhibited both isoforms almost equally. These results indicate that meloxicam is a potent anti-inflammatory agent with low gastric toxicity. One reason for its in vivo pharmacological profile may be related to its relative selectivity for COX-2 over COX-1. Thus, meloxicam may belong to a group of COX-2 selective anti-inflammatory agents with a better safety profile than conventional COX-1 and COX-2 nonselective anti-inflammatory agents.

Impaired cytosolic Ca2+ response to glucose and gastric inhibitory polypeptide in pancreatic beta-cells from triphenyltin-induced diabetic hamster

Oral administration of a single dose of triphenyltin compounds induces diabetes with decreased insulin secretion in rabbits and hamsters after 2-3 days without any morphological changes in pancreatic islets. In the present study, to test the possibility that the impaired insulin secretion induced by triphenyltin compounds could result from an impaired Ca2+ response in pancreatic beta-cells, we investigated the effect of triphenyltin-chloride (TPTCl) administration on the changes in the cytoplasmic Ca2+ concentration ([Ca2+]i) induced by secretagogues, such as glucose, high K+, gastric inhibitory polypeptide (GIP), and acetylcholine (ACh) in hamster pancreatic beta-cells. TPTCl administration caused partial suppression in 10 mM K+-induced rise in [Ca2+]i without suppressing the increase in [Ca2+]i evoked by 20-50 mM K+. Administration of TPTCl strongly inhibited the rises in [Ca2+]i induced by 27.8 mM glucose, 100 microM ACh in the presence of 5.5 mM glucose, and by 100 nM GIP in the presence of 5.5 mM glucose. In the ACh-induced response, TPTCl administration strongly suppressed the late sustained phase, while weakly suppressing the initial rise in [Ca2+]i. TPTCl administration significantly suppressed the rise of cAMP content in islet cells induced by 100 nM GIP with 1 mM 3-isobutyl-1-methylxanthine in the presence of 5.5 mM glucose (P < 0.01, N = 5-11). TPTCl administration also impaired the insulin secretion in islet cells induced by 27.8 mM glucose, 100 nM GIP in the presence of 5.5 mM glucose, and 100 microM ACh in the presence of 5.5 mM glucose (P < 0.05, N = 9-16). We conclude that the pathology of triphenyltin-induced diabetes in hamsters involves a defect in cellular Ca2+ response due to a reduced Ca2+-influx through voltage-gated Ca2+ channels.

Involvement of central neurotensin in thermoregulatory and neuroimmune function in pregnant rats exposed to heat

To examine a functional relationship among pregnancy and central neurotensin and thermoregulatory and neuroimmune systems during heat stress, we monitored colonic temperature in six virgin female rats and six pregnant rats (9 to 11 days gestation) exposed to a microwave source. We also assayed splenic natural killer cell activity (NKCA), blood corticosterone (CS), and ACTH as indicators of the hypothalamic-pituitary-adrenal axis, beta-endorphin (beta-EP), and neurotensin (NT) in discrete brain regions. Additionally, we clarified the effects of intracerebroventricular (icv) administration of NT antiserum on these same responses in pregnant rats exposed to heat stress. Repeated-measures analysis of variance showed significant main effects of heat and pregnancy and a significant interactive effect on colonic temperature. Significant elevation in blood CS, ACTH, beta-EP, and NT in the hypothalamus and significant reductions in splenic NKCA and NT in the nucleus accumbens were produced by heat. In the experiment examining the effect of icv administration of NT antiserum, significant main effects of heat and administration and a significant interactive effect on colonic temperature were observed. Icv administration of NT antiserum increased splenic NKCA and decreased blood beta-EP. These results show that pregnancy enhances thermal homeostasis, suggesting central thermoregulatory mechanisms through NT in nucleus accumbens and hypothalamus in which placental or pituitary beta-EP may be involved. NT and beta-EP seem to play central roles simultaneously in heat-induced immunosuppression during pregnancy. Clarification for the effects of NT antiserum on beta-EP in virgin rats or manipulation of agents related to opioid system should be the focus of future work.

Inhibitory effect of pregnancy on stress-induced immunosuppression through corticotropin releasing hormone (CRH) and dopaminergic systems

To clarify the involvement of pregnancy in the response of the neuroendocrine-immune system to stress, we examined splenic natural killer-cell-activity-(NKCA) and its relevant central and blood parameters in female virgin and pregnant rats (10 to 11 days gestation) exposed to forced water-immersion stress with durations of 90 min and 180 min. Decreases in splenic NKCA, corticotropin releasing hormone (CRH) in the hypothalamus, and increases in progesterone (P), beta-endorphin (beta EP), and dopamine (DA) metabolic ratios in the frontal cortex and nucleus accumbens produced by stress were recognized in the virgin rats, but not in the pregnant rats. Pregnancy reduced splenic NKCA in rats without stress, but elevated it in the rats exposed to stress with a duration of 180 min. These findings suggest inhibitory effects of pregnancy on stress-induced immunosuppression and neuroendocrine changes, thereby promoting homeostasis in the neuroendocrine-immune system against stress. Such enhanced homeostasis associated with pregnancy seemed to be mediated by the activation of placental P and placental or pituitary beta EP in cooperation with mesocortical and mesolimbic DA systems and hypothalamic CRH.

Responses of plasma catecholamines, renin-angiotensin-aldosterone system, and atrial natriuretic peptide to exercise in patients with essential hypertension

Neurohormonal responses to exercise have not been studied fully in patients with essential hypertension (HT). This study determined if neurohormonal responses to exercise are altered between three subgroups of HT categorized by basal plasma renin activity (PRA). Plasma norepinephrine, epinephrine, atrial natriuretic peptide (ANP), PRA, angiotensin II (AII), and aldosterone were measured at rest and after submaximal treadmill exercise in 39 patients with essential HT (WHO classes I-II) and 13 controls. Patients with HT were divided into three subgroups based on the PRA level [low-renin (< 0.5) HT (n = 14), normal-renin (0.5-2.0) HT (n = 13), and high-renin (> 2.0) HT (n = 12)]. Patients with HT had higher blood pressure during exercise compared to controls, but blood pressure responses were similar among low-, normal-, and high-renin HT. Neurohormonal factors were comparable between all hypertensives and controls, except for higher plasma AII at rest in patients with HT. When neurohormones were compared among three subgroups of HT, plasma norepinephrine and epinephrine responses were similar. Patients with high-renin HT had higher PRA and AII, and lower ANP levels at rest and after exercise. In all hypertensives, negative correlations were observed between resting PRA and resting ANP (r = -0.41, p < 0.01), as well as peak PRA and peak ANP (r = -0.33, p < 0.05). Thus, neurohormonal responses to exercise varied with similar cardiac responses among subgroups of essential HT stratified according to renin levels. Patients with high-renin HT had augmented renin-angiotensin system activity with a decrease in ANP levels both at rest and after exercise. A reciprocal relationship between renin-angiotensin system activity and ANP was observed both at rest and after exercise in HT.

Responses of catecholamines, renin-angiotensin system, and atrial natriuretic peptide to exercise in untrained men and women

1. Plasma norepinephrine (NE), epinephrine (E), renin activity (PRA), angiotensin II (ATII), aldosterone (ALD), and atrial natriuretic peptide (ANP) were measured in 20 male and 15 female subjects during submaximal treadmill test. 2. Exercise duration was not different between the two groups (male vs. female: 13.4 +/- 0.8 min vs. 11.6 +/- 0.7 min, ns). Female subjects had higher heart rate during exercise, while systolic blood pressure at peak exercise was higher in male subjects. 3. Plasma NE, E, ANP, and ATII responses were comparable between male and female subjects, but PRA both at rest and during exercise and ALD at rest were significantly higher in male subjects. 4. Cardiac responses to submaximal exercise were different between male and female subjects, but neurohormonal responses were comparable between the two groups except for the high PRA at rest and during exercise and high plasma ALD at rest in male subjects.

Effects of enalapril on the exercise capacity and neurohumoral factors during exercise in patients with chronic heart failure

The effects of enalapril on exercise capacity and neurohumoral factors during exercise were evaluated in 10 patients with heart failure. Echocardiograms and exercise testing with expired gas analysis were performed before and after enalapril. Blood samples were obtained before and after exercise. Both ejection fraction and percent fractional shortening increased with enalapril (p < 0.05). The anaerobic threshold and peak VO2 did not change with enalapril. Epinephrine and norepinephrine levels at peak exercise decreased with enalapril (p < 0.1). Plasma renin both at rest and at peak exercise increased with enalapril (p < 0.1). Angiotensin II was lower after enalapril both at rest and at peak exercise (p < 0.1 and p < 0.05, respectively). Aldosterone was lower after enalapril both at rest and at peak exercise (p < 0.05). Atrial natriuretic peptide (ANP) was lower after enalapril both at rest and at peak exercise. There was no significant correlations between peak VO2 and changes in neurohumoral factors before and after enalapril during exercise. In conclusion, neurohumoral changes with enalapril occurred during exercise even if exercise capacity did not improve. Moreover, the improvement of cardiac function at rest and neurohumoral factors with enalapril did not lead to a change of exercise capacity.

Augmented response in plasma atrial natriuretic peptide to dynamic exercise in patients with congestive heart failure

Neurohormonal activation is present and neurohormonal responses to dynamic exercise are altered in patients with congestive heart failure (CHF). The aim of this study was to determine if the responses of atrial natriuretic peptide (ANP) normalized for peak oxygen consumption (peak VO2) to exercise are augmented in patients with CHF. Ventilatory and ANP responses were assessed in 28 patients with CHF (NYHA classes II: 16, III: 12), 17 patients in NYHA class I, and 14 normal subjects during symptom-limited cardiopulmonary exercise testing. Plasma ANP was measured at rest and immediately after peak exercise. The increase in ANP was divided by peak VO2 and this ratio [ANP-Exercise Ratio: (peak ANP-rest ANP)/peak VO2] was compared among the 3 groups. Peak VO2 (Normal, NYHA I, CHF: 29.9 +/- 1.7, 24.0 +/- 1.3, 17.4 +/- 0.8 ml/min per kg), anaerobic threshold and peak work rate were lower in patients with CHF. The resting ANP level was significantly higher in patients with CHF (Normal, NYHA I, CHF: 35.4 +/- 4.6, 42.9 +/- 5.8, 80.8 +/- 12.9 pg/ml). The ANP level increased during exercise in all 3 groups, and patients with CHF had a significantly higher ANP level than normal subjects and NYHA class I patients (Normal, NYHA I, CHF: 65.3 +/- 10.7, 75.9 +/- 14.4, 141.6 +/- 20.1 pg/ml). The ANP-Exercise Ratio in patients with CHF was significantly higher than those in normal subjects and NYHA class I patients (Normal, NYHA I, CHF: 0.96 +/- 0.26, 1.32 +/- 0.38, 3.59 +/- 0.72). These data suggest that patients with CHF but not those in NYHA class I have an augmented ANP response, as reflected by both absolute ANP levels and by the exercise ratio, which was normalized by the peak exercise level.

Family history-related risk of gastric cancer in Japan: a hospital-based case-control study

In Japan, there have been a few reports on the familiar factors of gastric cancer (GC) and on the GC risk related to family history (FH) at other cancer sites. We analyzed the association between GC occurrence and a positive FH of cancer of the stomach and of other sites in a hospital-based case-control study. The subjects included cases histologically confirmed as incident cancer of the stomach (n = 136; 86 male and 50 female patients) and sex and age (+/- 1 year)-matched controls. GC risk was high when a subject had a parental history of GC [Mantel-Haenszel odds ratio adjusted for sex and age (OR)=2.3; 95% confidence interval (95% CI):1.1-5.0]. GC risk was almost unity for a cancer FH of any other cancer site, even among closer relatives, suggesting little or no contribution to GC occurrence. The familial occurrence of GC found in this study suggests the existence of a genetic susceptibility to cancer of the stomach. Further, females tended to show higher GC risks than males, when reporting an affected mother (OR=6.0; 95% CI:1.1-31.4 and OR= 1.4; 95% CI:0.4-4.8, respectively), whereas males showed a slightly higher risk than females when reporting an affected father (OR=2.4; 95% CI:0.8-7.5 and OR=2.3; 95% CI:0.4-15.6, respectively). This suggests a possible gender difference in how environmental factors influence GC occurrence. The development of gastric tumors seems to be due to a complex and unknown interaction between environmental and genetic factors.

Catecholamines, renin-angiotensin-aldosterone system, and atrial natriuretic peptide at rest and during submaximal exercise in patients with congestive heart failure

The aim of this study was to determine the responses of plasma catecholamines, renin-angiotensin-aldosterone (RAA) activity, and plasma atrial natriuretic peptide (ANP) to exercise in patients with congestive heart failure (CHF). Cardiac and neurohormonal responses were assessed during submaximal treadmill exercise testing in 23 patients with CHF (New York Heart Association classes I-III) and 13 control subjects (without CHF). Plasma norepinephrine, epinephrine, renin activity (PRA), angiotensin II (ATII), aldosterone, and ANP were measured at rest and immediately after exercise. Exercise duration was shorter in patients with CHF (control, 10.4 +/- 0.9 minute; CHF, 6.2 +/- 0.7 minute; P < 0.01). Heart rate and blood pressure responses were similar except for the smaller peak heart rate (control, 145 +/- 5 beats per minute; CHF, 129 +/- 4 beats per minute; P < 0.05) and higher systolic blood pressure at recovery stage (control, 122 +/- 4 mm Hg; CHF, 142 +/- 4 mm Hg; P < 0.01) in patients with CHF. At rest, plasma norepinephrine levels were insignificantly higher in patients with CHF (control, 110 +/- 10 pg/mL; CHF, 170 +/- 26 pg/mL; P = 0.09), and ANP levels (control, 40 +/- 5 pg/mL; CHF, 94 +/- 17 pg/mL; P < 0.05) and PRA levels (control, 0.77 +/- 0.11 ng/mL/hr; CHF, 4.33 +/- 1.25 ng/mL/hr; P < 0.05) were significantly higher. There were no differences in peak norepinephrine, epinephrine, or ANP between the two groups. Angiotensin II and aldosterone levels were similar between the two groups, although, in patients with CHF, there was a trend toward higher levels of ATII while at rest (control, 12.4 +/- 1.4 pg/mL; CHF, 20.3 +/- 3.3 pg/mL; P = 0.08) and at peak (control, 20.5 +/- 1.8 pg/mL; CHF, 41.0 +/- 9.4 pg/mL; P = 0.10). Peak values of PRA, ATII, and aldosterone positively correlated with respective resting values of PRA (r = 0.88 ng/mL/hr, P < 0.01), ATII (r = 0.63 pg/mL, P < 0.01), and aldosterone (r = 0.99, P < 0.01). Peak norepinephrine and peak ANP also positively correlated with respective resting values of norepinephrine (r = 0.58 pg/mL, P < 0.05) and ANP (r = 0.94, P < 0.01). Analysis of these results showed that patients with CHF had significantly higher levels of PRA and ANP at rest, and a trend toward augmentation in RAA system activity during exercise with less exercise workload. Basal level of neurohormones seemed to be an important determinant for the degree of exercise-induced neurohormonal activation in patients with CHF.

Length-dependent activation in intact ferret hearts: study of steady-state Ca(2+)-stress-strain interrelations

We examined the steady-state stress-strain relationships and the steady-state stress-intracellular calcium concentration ([Ca2+]i) relationship in intact ferret hearts and compared these to previously published analogous relationships in skinned and intact muscle. Langendorff-perfused ferret hearts were treated with ryanodine and tetanized by rapid stimulation to create steady-state conditions. [Ca2+]i was measured concurrently by macroinjected aequorin. Over a range of volumes corresponding to strains between 1.0 and 0.75, steady-state stress decreased by 33% when saturating levels of perfusate calcium were used, indicating the degree to which physical factors contribute to the Frank-Starling relationship. The steady-state stress-[Ca2+]i relationship was sigmoidal with a mean Hill coefficient (nH) of 4.91 +/- 0.29 at a strain of 1.0, and the [Ca2+]i required for half-maximal activation (K1/2) was 0.41 +/- 0.03 microM. K1/2 increased and nH decreased with decreasing strains. These results are similar to those observed in intact muscle but differ quantitatively from results obtained in isolated, skinned preparations. Based on these results, we suggest that whole heart function can be related to average sarcomere function without the need for complex models of ventricular structure.

Responses of plasma norepinephrine and renin-angiotensin-aldosterone system to dynamic exercise in patients with congestive heart failure

BACKGROUND

Neurohormonal activation is present and neurohormonal responses to dynamic exercise are altered in congestive heart failure (CHF). Responses of plasma norepinephrine in various degrees of heart failure have been investigated, but the responses of the renin-angiotensin-aldosterone system have not been studied in relation to the severity of CHF. The aim of this study was to determine if the responses of the renin-angiotensin-aldosterone system to exercise are augmented according to the severity of CHF.

METHODS AND RESULTS

Ventilatory and neurohormonal responses were assessed in 38 patients with CHF (New York Heart Association class: I, 13 patients; II, 14 patients; III, 11 patients) and 11 normal subjects during symptom-limited cardiopulmonary exercise testing. Plasma norepinephrine, renin activity, angiotensin II, and aldosterone were measured at rest and at peak exercise. The increments in neurohormones were divided by peak oxygen consumption, and these ratios (norepinephrine exercise ratio, plasma renin activity-exercise ratio, angiotensin II-exercise ratio, aldosterone-exercise ratio) were compared among groups. Peak oxygen consumption and anaerobic threshold decreased progressively with the severity of CHF. Neurohormonal profiles at rest showed that plasma norepinephrine levels were significantly higher, and the renin-angiotensin-aldosterone system was augmented only in patients with class III CHF. Neurohormones increased during exercise both in patients with CHF and in normal subjects, but patients with class III CHF had significantly higher plasma renin activity (10.11 +/- 2.32 ng/mL/h), angiotensin II (73.9 +/- 14.2 pg/mL), and aldosterone (265.2 +/- 61.1 pg/mL) than did normal subjects. Plasma renin activity-exercise ratio, angiotensin II-exercise ratio, and aldosterone-exercise ratio in patients with class III CHF were significantly higher compared to normal subjects. This augmentation of the renin-angiotensin-aldosterone system was not observed in class I or II patients. Peak plasma norepinephrine levels were not different among normal subjects and subgroups of CHF patients, but the norepinephrine-exercise ratio was significantly higher in classes II and III CHF compared to normal subjects.

CONCLUSIONS

These data suggest that neurohormonal excitation during exercise increases along with the severity of CHF when normalized for peak exercise level.

Changes in activity of superoxide dismutase in the human endometrium throughout the menstrual cycle and in early pregnancy

To investigate the possible role of the superoxide radical and its scavenging system in the human endometrium, the immunohistochemical distribution of superoxide dismutase (SOD), activities of SOD and lipid peroxide concentrations were studied in the human endometrium throughout the menstrual cycle and in early pregnancy. The endometrial epithelium showed a positive immunostaining for Cu, Zn-SOD and Mn-SOD throughout the entire menstrual cycle and in early pregnancy. In the stroma, weak immunostaining for Cu,Zn-SOD and moderate immunostaining for Mn-SOD were observed in the predecidual cells in the late secretory phase. Decidual cells in early pregnancy showed strong immunostaining for Cu,Zn-SOD and Mn-SOD. Total SOD activity in the endometrium increased from early proliferative phase to mid-late proliferative phase and further increased in the mid-secretory phase, and decreased in the late secretory phase. The total SOD activity in the endometrium of of early pregnancy was the same level as that in the mid-secretory phase. Cu,Zn-SOD and Mn-SOD activities changed in a similar manner to total SOD activity throughout the menstrual cycle and in early pregnancy. Lipid peroxide concentration in the endometrium increased from early proliferative phase to mid-late proliferative phase and further increased in the late secretory phase. However, lipid peroxide concentration in the endometrium of early pregnancy was the same as that in the mid-secretory phase. These results suggested that the superoxide radical and its scavenging system may play an important role in the regulation of human endometrial function.

[Vitrectomy in Coats' disease]

Four eyes of four patients with Coats' disease underwent vitrectomy because of exudative or tractional detachments involving the macula or premacular fibrosis. All cases had gelatinous vitreous and had no complete posterior vitreous detachment. The exudates decreased and the retina reattached after removing vitreous traction and coagulating abnormal vessels with endodiathermy and not removing subretinal fluid in 3 eyes with retinal detachment. In one eye with tractional detachment, retinal breaks were found beneath the proliferative membrane during the initial vitrectomy procedure. This eye needed multiple operations because of recurrent traction by the remaining peripheral vitreous. Exudation into the vitreous and vitreous traction may cause mutual progression in these eyes, and vitrectomy is an effective treatment, although there are difficulties in removing vitreous traction completely.

Ammonia response to exercise in patients with congestive heart failure

OBJECTIVE

To assess energy depletion in skeletal muscle in patients with congestive heart failure by measuring blood purine metabolites during exercise and, at the same time, determine the implications of the ammonia response to exercise in these patients.

SETTING

Tottori University Hospital, Yonago, Japan.

PATIENTS

49 heart failure patients (New York Heart Association (NYHA) grades I-III) and 16 normal subjects.

MAIN OUTCOME MEASURES

Blood lactate, ammonia, and hypoxanthine levels were measured during exercise with expired gas analysis.

RESULTS

In normal exercising subjects as well as in each heart failure subgroup, the ammonia threshold was significantly higher than both the lactate threshold [control: 21.8 (SD 5.3) v 17.4 (3.3) ml/kg/min; NYHA class I: 18.9 (3.8) v 15.5 (2.6); class II: 14.8 (2.5) v 12.7 (2.4); class III: 13.5 (2.6) v 11.8 (2.5)] and the ventilatory threshold (P < 0.01). The difference between the ammonia and lactate thresholds was noted in all normal subjects and in all heart failure patients. The ammonia threshold, however, was significantly lower in heart failure patients than in normal subjects and it decreased with increasing NYHA class (P < 0.01). Maximum ammonia levels were lower in the heart failure group and decreased further with higher NYHA classifications [control: 198 (52) mg/dl; NYHA class I: 170 (74); class II: 134 (58); class III: 72 (15); P < 0.01]. There were significant correlations between maximum ammonia values and maximum lactate, oxygen consumption, and hypoxanthine levels (r = 0.74, 0.48, and 0.87, respectively; P < 0.001).

CONCLUSIONS

The ammonia threshold may reflect the onset of ATP depletion in exercising skeletal muscles, as opposed to the onset of anaerobic respiration. It seems therefore that energy depletion in skeletal muscles during exercise occurs after attaining the anaerobic threshold. Both aerobic and anaerobic capacities of skeletal muscle are reduced in patients with congestive heart failure.

Progesterone inhibits superoxide radical production by mononuclear phagocytes in pseudopregnant rats

This study investigated the changes in superoxide radical production by mononuclear phagocytes in the corpus luteum (CL) during pseudopregnancy in rats. Activity of superoxide radical production was determined by the conversion of nitro blue tetrazolium (NBT) to blue formazan deposit. Rats received 10 mg NBT via the abdominal aorta on day 3, 7, or 13 of pseudopregnancy and were autopsied 1 min later to prepare the histological sections. The cells with blue formazan deposits (NBT-positive cells) in the CL were scarce on days 3 and 7 of pseudopregnancy and significantly increased on day 13 of pseudo-pregnancy. On the other hand, simultaneous administration of 100 micrograms phorbol 12-myristate 13-acetate, which activates mononuclear phagocytes to produce superoxide radical, significantly increased the numbers of NBT-positive cells in the CL on day 7 of pseudopregnancy, but not in the CL on day 3 or 13 of pseudopregnancy. To study the possibility that superoxide radical production by mononuclear phagocytes is inhibited by progesterone on day 7 of pseudopregnancy, peritoneal mononuclear phagocytes prepared on day 7 or 13 of pseudopregnancy were preincubated with 10, 50, or 100 ng/ml progesterone for 6 h and then stimulated with phorbol 12-myristate 13-acetate. Superoxide radical production was measured by the cytochrome c reduction method. One hundred nanograms per ml progesterone significantly inhibited superoxide radical production by mononuclear phagocytes, and this inhibitory effect of progesterone was significantly blocked by the simultaneous addition of RU486 (10(-7) M). These results suggested that progesterone inhibited superoxide radical production by the mononuclear phagocytes in the CL during midpseudopregnancy in rats.

Role of prostaglandin H synthase-2 in prostaglandin E2 formation in rat carrageenin-induced pleurisy

Rat carrageenin-induced pleurisy was used to clarify the role of prostaglandin H synthase (PGHS)-2 in acute inflammation. Intrapleural injection of 0.2 ml of 2% lambda-carrageenin induced accumulation of exudate and infiltration of leukocytes into the pleural cavity. When PGHS-1 and -2 proteins in the pleural exudate cells were analyzed by Western blot analysis, PGHS-2 was detectable from 1 hr after carrageenin injection. Its level rose sharply, remained high from 3 to 7 hr after injection, and then fell to near the detection limit. PGHS-1 was also detected, but kept almost the same level throughout the course of the pleurisy. Levels of prostaglandin (PG) E2 and thromboxane (TX) B2 in the exudate increased from hour 3 to hour 7, and then declined. Thus, the changes of the level of PGE2 were closely paralleled those of PGHS-2. The selective PGHS-2 inhibitors NS-398, nimesulide and SC-58125 suppressed the inflammatory reaction and caused a marked decrease in the level of PGE2 but not in those of TXB2 and 6-keto-PGF 1 alpha. These results suggest that the PGHS-2 expressed in the pleural exudate cells may be involved in PGE2 formation at the site of inflammation.

Changes in lipid peroxide and antioxidant enzyme activities in corpora lutea during pseudopregnancy in rats

This study investigated the involvement of lipid peroxidation and antioxidant enzymes in the regulation of luteal function in pseudopregnant rats. The activities of superoxide dismutase (SOD), a specific scavenger of superoxide radicals, and glutathione peroxidase, a scavenger of hydrogen peroxide, and lipid peroxide concentrations were measured in the corpus luteum on days 1, 3, 5, 7, 9, 11 and 13 of pseudopregnancy. The activity of SOD in the corpus luteum gradually increased until day 9 of pseudopregnancy and decreased thereafter, in a similar manner to serum progesterone concentration. Glutathione peroxidase activity significantly increased from day 1 to day 3 and remained high until day 11 of pseudopregnancy. The concentrations of lipid peroxides in the corpus luteum increased from day 3 to day 13 of pseudopregnancy. The involvement of prostaglandin F2 alpha (PGF2 alpha) in the production of lipid peroxides in regression of the corpus luteum was investigated by administering PGF2 alpha (3 mg kg-1, s.c.) or saline on days 7, 9 and 12 of pseudopregnancy. Each group of rats was autopsied 2 h later, and SOD activity, glutathione peroxidase activity and the concentration of lipid peroxides in the corpus luteum were determined. PGF2 alpha significantly increased lipid peroxide concentrations in the corpus luteum on days 7, 9 and 12 of pseudopregnancy (approximately twofold increases on days 7 and 9, and a fivefold increase on day 12, compared with the control that received saline). The activity of SOD in the corpus luteum was significantly increased by PGF2 alpha on days 7 and 9, but not on day 12, of pseudopregnancy. PGF2 alpha did not cause any significant changes in glutathione peroxidase activity in the corpus luteum on days 7, 9 and 12 of pseudopregnancy. It is concluded that lipid peroxides play an important role in regulating luteal function in pseudopregnant rats.

Proliferation of hepatocytes and attenuation from carbon tetrachloride hepatotoxicity by gadolinium chloride in rats

Intravenous injection of gadolinium chloride (GdCl3) at a dose of 10 mg/kg caused an increase in proliferating cell nuclear antigen labeling index and the grade of pyronin positivity (RNA level) in rat liver. In CCl4-exposed rats, pretreatment with GdCl3 also showed a preventive effect of the liver injury both biochemically and histologically. Moreover, the proliferative action preceded the attenuative effect of the liver injury. Results suggest that GdCl3 induces hepatocyte proliferation, and this action of GdCl3 may modify the development of CCl4-induced liver injury.

The hemodynamic basis for the cardiac effects of parathyroid hormone (PTH) and PTH-related protein

PTH and PTH-related protein (PTHrP) have been regarded to have positive inotropic effects on the heart as well as positive chronotropic and vasodilator effects. However, inotropy due to a direct effect of these peptides has not heretofore been distinguished from an indirect inotropic effect as a result of altered heart rate or coronary flow. The aim of this study was to determine whether PTH and PTHrP have direct inotropic effects in isolated perfused rat hearts. Three groups of hearts were studied; in all groups, hearts contracted isovolumically and were perfused with a constant coronary pressure. In the control group, heart rate, coronary flow, peak pressure (LVPmax), peak rate of rise of LV pressure (dP/dtmax), and peak intracellular calcium (measured by aequorin) all increased with PTH and PTHrP in a dose-dependent manner. When heart rate was fixed by pacing in a second group of rats, PTH and PTHrP increased coronary flow, LVPmax, and dP/dtmax significantly, indicating that inotropic actions were not mediated solely by chronotropic effects. However, when heart rate was fixed by pacing and, additionally, coronary flow was held constant (by maximal prevasodilation with nitroprusside) in a third group of rats, there was no significant effect of either PTH or PTHrP on LVPmax, dP/dtmax, or peak intracellular calcium. To demonstrate the responsiveness of this latter preparation to inotropic stimulation, the beta-adrenergic agonist, isoproterenol, increased LVPmax, dP/dtmax, and peak calcium even when heart rate was fixed and vasodilation was maximal. Thus, PTH and PTHrP are inotropic agents by virtue of their influence on coronary flow and heart rate, but not by any direct effect on contractile elements in the heart.

Nicorandil suppressed myocardial purine metabolism during exercise in patients with angina pectoris

To elucidate the effect of Nicorandil on myocardial energy metabolism and myocardial sympathetic activity, we administered Nicorandil orally to eight patients with angina pectoris prior to exercise testing. Arterial and coronary sinus levels of lactate, ammonia, hypoxanthine (HX), adrenaline and noradrenaline were measured during exercise in order to determine the irrespective myocardial extraction ratios (MER). Compared to placebo, Nicorandil increased the time to development of significant ST depression (322 vs 390 s) while decreasing the maximum amplitude of ST depression (0.244 vs 0.216 mV). Heart rate, systolic blood pressure, and the rate pressure product during exercise were not significantly affected. The MER of lactate, measured during exercise, was significantly higher after Nicorandil than placebo (13.6 vs 27.9). Similarly, the MERs of ammonia and HX were significantly higher after Nicorandil (-46.0 vs 7.4% and -47.0 vs 9.9% respectively). Nicorandil, had no apparent effect on myocardial sympathetic activity as the MERs of adrenaline and noradrenaline were essentially unaffected. We conclude that Nicorandil decreased myocardial ischaemia and suppressed myocardial accelerated purine metabolism (a marker of cellular energy metabolism) during exercise in patients with angina pectoris. This effect appears not to be related to myocardial sympathetic activity.

The determination of nitrite and nitrate in human blood plasma by capillary zone electrophoresis

The determination of nitrite and nitrate in human blood plasma by capillary zone electrophoresis (CZE) is described. Electrophoresis was carried out in a 65 cm long, 75 microns wide silica capillary, using 750 mM sodium chloride containing 5% NICE-Pak OFM Anion-BT (an additive reversing the electroosmotic flow) as running buffer, at a potential of 20 kV, with on-column UV detection at 214 nm. Under these conditions, the two anions migrated in the order of nitrite and nitrate, completely resolved from each other. Forty-one samples of ultrafiltered blood plasma of healthy volunteers were analyzed. The concentrations of nitrite and nitrate were 0.15 +/- 0.07 mg/L and 3.2 +/- 1.6 mg/L (mean +/- SD), respectively, with a linear correlation in the range of 0.1-50 mg/L. The within-day and between-day coefficients of variation (CVs) for nitrite and nitrate were lower than 5% and 8%, respectively. The recovery was 97-114%. The estimated plasma volume needed for each determination was 108 nL.

Role of Kupffer cells in rat liver injury induced by diethyldithiocarbamate

The hepatotoxicity of diethyldithiocarbamate was examined using an in vitro rat liver slice system. Concentration- and time-dependent losses of intracellular K+ and adenosine triphosphate (ATP) levels were observed in rat liver slices incubated with diethyldithiocarbamate at concentrations between 1 and 10 mM over a 4-h period. Histological study revealed perivenous hepatocyte damage. To examine the involvement of Kupffer cells in diethyldithiocarbamate-induced cytotoxicity, rats were injected intravenously with 10 mg/kg of gadolinium chloride (GdCl3) which diminishes Kupffer cell function. Incubation of liver slice preparations from the GdCl3-treated rats with diethyldithiocarbamate showed marked inhibition of the cytotoxicity induced by diethyldithiocarbamate. Moreover, in vitro addition of manganese-superoxide dismutase, a superoxide anion scavenger, or dimethyl sulfoxide (DMSO), a hydroxyl radical scavenger, also showed potent inhibition. However, dexamethasone, an inhibitor of tumor necrosis factor, and N,N'-diphenyl-p-phenylenediamine (DPPD), an antioxidant, showed partial prevention of cytotoxicity. Formazan deposits formed as a result of nitro blue tetrazolium reduction were found in Kupffer cells at an early stage after diethyldithiocarbamate treatment, while lipid peroxidation occurred after 3 h. Both pretreatment with GdCl3 in vivo and addition of DMSO in vitro prevented the increase in lipid peroxidation within the liver slice preparations induced by diethyldithiocarbamate. These findings suggest that Kupffer cell function may be involved in the pathogenesis of diethyldithiocarbamate hepatotoxicity.

Effects of zinc on production of active oxygen species by rat neutrophils

The effects of zinc on the production of active oxygen species were investigated in rat neutrophils by chemiluminescence and spectrophotometric assays. The luminol-dependent chemiluminescence in unstimulated neutrophils showed a single peak. Zinc at concentrations lower than 0.1 mM augmented the intensity of chemiluminescence and showed a bimodal pattern, the first peak of which was inhibited by superoxide dismutase and catalase, while the second peak disappeared in the presence of catalase, but was unaffected by superoxide dismutase. At the same concentrations of zinc, O2- and H2O2 production increased, but secretion and activity of myeloperoxidase were not affected. Zinc at 0.1 mM enhanced the second peak of luminol-dependent chemiluminescence, and concomitantly O2- and H2O2 production of neutrophils stimulated with formyl-methionyl-leucyl-phenylalanine. Homogenized neutrophils showed a bimodal pattern on induction by zinc, the second peak of which was inhibited slightly by catalase and completely by sodium azide, but was not inhibited by superoxide dismutase. Zinc-induced O2- production was inhibited by pertussis toxin, but was not significantly inhibited by a protein kinase C inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7), or a calmodulin antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7). These results suggest that zinc can augment luminol-dependent chemiluminescence by increasing O2- production through the classical signal transduction pathway, and by increasing H2O2 not via O2-.

An approach for an immunoaffinity AIDS sensor using the conservative region of the HIV envelope protein (gp41) and its monoclonal antibody

A monoclonal antibody for the conservative region of gp41, which is one of the HIV envelope proteins, was produced. The antigen determining site of gp41 was examined using the epitope mapping technique, followed by an enzyme linked immunosorbent assay. Some peptides had comparable affinities for the monoclonal antibody, but the peptide EGIEE, having a slightly weaker immunoaffinity than gp41, was the most preferable for the construction of an immunoaffinity AIDS sensor. For the detection of gp41, EGIEE was labelled with catalase and used as a mimic antigen; it was bound to the antibody present on an immuno-membrane and, due to the replacement reaction of the mimic antigen by gp41, indirect quantitative measurement of gp41 was possible using an oxygen electrode. Anti-gp41 antibody was also detected using a mimic antibody, which was chemically modified with polyethylene glycol. An immunoaffinity AIDS sensor was constructed using the mimic molecules which were tailored to have a suitable immunoaffinity for HIV antigen and/or antibody.

Mechanisms of the Frank-Starling phenomena studied in intact hearts

The impact of ventricular volume on the relationship between intracellular calcium and ventricular pressure under steady-state conditions was determined in intact ferret hearts. The results reveal major quantitative differences and minor qualitative differences between these relations and those previously measured in isolated intact and skinned cardiac muscle. The importance of these differences is discussed within the context of developing a comprehensive mechanistic theory to describe load-dependence of the intact ventricle.

Changes of QRS axis in transient myocardial ischaemia induced by percutaneous transluminal coronary angioplasty

The QRS axis of 130 consecutive patients with coronary artery disease undergoing percutaneous transluminal coronary angioplasty (PTCA) were measured before balloon inflation and just before balloon deflation. Patients were divided into two groups. Group A (103) had angina pectoris and/or non-transmural old myocardial infarction with no abnormal Q waves; group B (27) had an old transmural myocardial infarction with abnormal Q waves. In group A, the QRS axis had significantly shifted to the left in patients with left anterior descending artery (LAD) occlusion (from 68.0 +/- 42.7 degrees to 40.2 +/- 44.6 degrees, P < 0.001); however in those patients without involvement of the major septal branch, significant axis changes were not observed (from 53.6 +/- 34.1 degrees to 49.8 +/- 33.1 degrees). When the right coronary artery (RCA) was occluded in group A, the QRS axis shifted to the right significantly (from 63.2 +/- 40.0 degrees to 89.8 +/- 30.1 degrees. P < 0.01); during left circumflex artery (LCX) occlusion, no significant axis shift was observed. In group B, no significant axis shift was observed either in patients with occlusion of the LAD or the RCA. It is concluded that transient left axis deviation reflects an obstructive lesion of the proximal portion of the LAD with involvement of the major septal branch, and transient right axis deviation reflects an obstructive lesion of the RCA.

Identification of EGF as an angiogenic factor present in conditioned medium from human salivary gland adenocarcinoma cell clones with varying degrees of metastatic potential

We have previously shown that conditioned medium (CM) from metastasizing human salivary gland adenocarcinoma cell clones contains factor(s) that stimulate the proliferation and migration of bovine aortic endothelial (BAE) cells, and inhibit the production of collagenases by BAE cells (Azuma M. et al. (1993) Cancer Lett., 73, 85-93). To further characterize this, we evaluated the expression level of epidermal growth factor (EGF) secreted by a non-metastasizing cell clone (HSGc) and its metastasizing cell clones, and analysed the effect of EGF on the biologic behaviors of BAE cells. When the secretion of EGF by cell clones was estimated by enzyme-linked immunosorbent assay, metastasizing cell clones released a large amount of EGF as compared with HSGc. However, the number of EGF receptor was detected consistently at a level that was similar in all cell clones. With regard to the effect of EGF on the malignant potential of cell clones such as proteolytic aggressiveness, EGF did not affect the secretion of both collagenases and their inhibitor from cell clones. Alternatively, exogenous EGF stimulated the proliferation and migration of BAE cells, and inhibited the secretion of collagenases from BAE cells. Neutralization with a neutralizing antibody of EGF released into CM abolished the inhibitory effect of CM on the secretion of collagenases from BAE cells. Thus, the CM-contained factor, which is responsible for the induction of biologic behaviors of BAE cells, can be attributed to EGF.

Effects of diethyldithiocarbamate on activating mechanisms of neutrophils

The effects of diethyldithiocarbamate on superoxide release by rat neutrophils were investigated in a chemiluminescence study. Diethyldithiocarbamate augmented lucigenin-dependent chemiluminescence in a concentration-dependent manner and inhibited luminol-dependent chemiluminescence at concentrations of 0.1-1 microM. In contrast, after the addition of 0.1 mM diethyldithiocarbamate, the chemiluminescence was markedly enhanced. Diethyldithiocarbamate inhibited both the myeloperoxidase activity of neutrophils and the chemiluminescence generated in a cell-free horseradish peroxidase/H2O2 and H2O2/HOCl system. The increase in lucigenin-dependent chemiluminescence brought about by diethyldithiocarbamate was inhibited by H-7, ML-7, W-7, EGTA and pertussis toxin. These results suggest that diethyldithiocarbamate may stimulate O2- production by a guanosine 5'-triphosphate protein-mediated and Ca(2+)-dependent process and that the increase in O2- release by neutrophils may be dependent not only on the direct stimulation of the signal transduction pathway but also on the increase in O2- by reducing the effect of the hydroperoxide (H2O2)-myeloperoxidase system.

[Response to a questionnaire on DNR-order from 307 trustee members of Japanese Medical Societies]

A questionnaire on the use of DNR-order was conducted on 427 trustee members of Japan Society of Reanimatology, Intensive Care Medicine and Anesthesiology with responses from 307 or 71.9%. The results of the questionnaire are as follows: DNR-order is unnecessary, 2.9%. Necessary depending on the situation, 96.7%. Here dying in dignity was the main reason for necessity of DNR-order and ethical, legal and technical problems were the reasons cited for objection. Patients' will is indispensable for DNR-order, 11.4%. Patients' will is not indispensable, 84.9%. Quality and quantity of treatment after the decision of DNR-order should not be limited or withdrawn, 21.2%. Should be withdrawn except for respirator, 60.6%. The percentage of those who had carried out a DNR-order was 69.1% (most of them more than once), but half of them did not describe the order on the chart. A guideline for a DNR-order by scientific societies and/or governmental policy for a DNR-order should be made and publicized not only for the benefit of the patients and their families but also for physicians themselves.

Zinc hydroxide induced respiratory burst in rat neutrophils

The effects of zinc hydroxide on the respiratory burst and phagocytosis by rat neutrophils were examined. Zinc hydroxide induced an increase in oxygen consumption and O2- production. Electronmicroscopy showed that neutrophils engulfed zinc hydroxide particles by phagocytosis. Pertussis toxin (0.25, 0.5, 1.0 micrograms/ml) and EGTA (1, 2, 5 mM) inhibited zinc hydroxide-induced O2- production in a dose-dependent manner. The inhibitors of protein kinase C, 1-(5-isoquinolinesulfonyl)-2-methyl-piperazine and N-[2-(methylamino)ethyl]-5-isoquinolinesulfonamide inhibited zinc hydroxide-induced O2- production with IC50 values ranging between 10 microM and 25 microM. The inhibitory study using an inhibitor of myosin light chain kinase, 1-(5-iodo-naphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazepine, showed IC50 values ranging from 5 microM to 10 microM. These findings indicate that zinc hydroxide induces respiratory burst and phagocytosis by rat neutrophils.

Perfusion reserve of coronary collateral circulation and its significance in the development of exercise-induced ischemia in patients with multivessel disease

To assess the perfusion reserve of coronary collateral circulation, we analyzed exercise-stress tomographic thallium-201 myocardial images in 12 patients who had total occlusion in the right coronary artery (RCA) or left circumflex coronary artery (LCX) with well-developed collateral circulation and 90% stenosis in the left anterior descending coronary artery (LAD). In 6 of the 12 patients, the collateral circulation was non-jeopardized (group A). In the remaining 6 patients, the collateral circulation was jeopardized (group B). All 6 of the patients in group A had an exercise-induced decrease in thallium uptake in the segments supplied by the occluded RCA or LCX with collateral circulation, and 3 (50%) of these 6 also showed a decrease in thallium uptake in the segments supplied by the LAD. All 6 of the patients in group B also had an exercise-induced decrease in thallium uptake in the segments supplied by the occluded RCA or LCX with collateral circulation, but none showed a decrease in thallium uptake in the segments supplied by the LAD. In conclusion, the perfusion reserve of collateral circulation is equal to or less than 90% stenosis and myocardial ischemia occurs first in the collateralized segments during exercise in patients with jeopardized collateral circulation.

[Damage to cultured corneal endothelium caused by ultrasound during phacoemulsification]

An experimental study was performed to estimate the degree of corneal endothelial damage caused by ultrasound during phacoemulsification. Cultured corneal endothelium prepared from bovine eyes was exposed to ultrasound. Dead cell rates were determined by counting the number of cells positively stained by trypan blue under various conditions of ultrasonic radiation. Dead cell rate increased from 13 +/- 2% to 39 +/- 4% (n = 5, Mean +/- S.D.) as ultrasonic duration was prolonged from 15 seconds to 45 seconds. Dead cell rate increased from 6 +/- 1% to 39 +/- 4% as ultrasonic power increased from 60% to 100%. Dead cell rate increased from 8 +/- 1% to 44 +/- 11% as the distance of the phaco tip decreased from 7 mm to 4 mm. Dead cell rate increased from 4 +/- 2% to 35 +/- 7% as the angle of the phaco tip increased from 30 degrees to 90 degrees. We confirmed that endothelial damage depended on ultrasonic duration, ultrasonic power, the distance of the phaco tip, and the angle of the phaco tip. We suggest that the endothelium is damaged mainly by shock waves emanating from the phaco tip.

Effects of media conditioned by a non-metastasizing human salivary gland adenocarcinoma cell clone and metastasizing clones from salivary gland and various other tissues on the proliferation, migration and protease production of bovine aortic endothelial cells in vitro

We demonstrate the role in tumor-associated angiogenesis of factors released into conditioned medium (CM) from in vitro human salivary gland cell clones with biological phenotypes ranging from non-metastasizing to metastasizing. A non-metastasizing human salivary gland adenocarcinoma cell clone HSGc and its subclone with metastatic potential (Gc2-100 cl-1) were employed. We also used metastasizing cell clones obtained by explant cultures of organs of Gc2-100 cl-1 tumor-bearing nude mouse. The proliferation and migration of bovine aortic endothelial (BAE) cells were significantly stimulated by the addition of CM obtained from Gc2-100 cl-1 and metastasizing cell clones, while CM from HSGc was ineffective. When the effect on protease secretion by BAE cells was examined, CM from Gc2-100 cl-1 and metastasizing cell clones inhibited the secretion of type IV collagenases by BAE cells much more than did CM from HSGc. These findings, therefore, may imply that Gc2-100 cl-1 and metastasizing cell clones secrete angiogenic factors that stimulate not only the proliferation and migration of endothelial cells but also the formation of basement membrane components necessary for the reconstruction of new blood vessels at migrated sites of endothelial cells by preventing the degradation of basement membrane component, type IV collagen.

Acute hemodynamic effects of bunazosin in congestive heart failure--differing responses according to degree of cardiac dysfunction

1. Hemodynamic responses to Bunazosin (BZN) in congestive heart failure (CHF) were evaluated for 6 hours (hr) in 30 patients (A, normal cardiac function; B, mild cardiac dysfunction; C, severe cardiac dysfunction). 2. For 6 hr after BZN, the increments of cardiac index (delta CI) and stroke volume index (delta SVI) with BZN were higher in groups A and B than in group C. 3. A significant positive correlation was observed between ejection fraction and maximum delta CI and SVI, and between % fractional shortening and maximum delta CI and SVI. 4. These data showed that BZN improved the hemodynamics of CHF patients and that patients in groups A and B responded well to this vasodilator, however, patients in group C did not.

Role of plasminogen activators, metalloproteinases and the tissue inhibitor of metalloproteinase-1 in the metastatic process of human salivary-gland adenocarcinoma cells

An in vitro system has been established in which conversion from non-metastasizing to metastasizing adenocarcinoma cells can be induced, and subsequently subjected to analysis of the expression of proteases and tissue inhibitor of metalloproteinases-1 (TIMP-1). A human salivary-gland adenocarcinoma cell clone HSGc, with no metastatic ability, was exposed to N-methyl-N-nitrosourea (MNU). Following exposure to MNU, cells with altered morphology were cloned. Upon s.c. inoculation into nude mice, MNU-treated HSGc clones formed metastatic foci in various organs, and then 5 metastasizing clones were isolated. Evaluation of expression of tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA), metalloproteinases and TIMP-1 was performed by means of enzyme immunoassay, zymogram, or immunoblot. MNU-treated HSGc and metastasizing clones were found to secrete high levels of tPA, while HSGc produced undetectable levels of this enzyme. Expression of uPA was not observed in any of the cell clones. When the secretion of gelatinolytic enzymes was examined, metastasizing clones produced higher levels of 57- and 32-kDa, but not of 92- or 72-kDa gelatinases, as compared to HSGc cells. Although TIMP-1 was detected in all cell clones, metastasizing clones secreted less TIMP-1 than HSGc cells; in addition, one metastasizing clone produced TIMP-1 with a molecular weight distinct from that of 28-kDa TIMP-1. Our results suggest that the acquisition of metastatic ability by human salivary-gland tumor cells is closely associated with increased secretion of several metalloproteinases as well as decreased or altered TIMP-1 expression.

Effects of volume and pressure overloads and myocardial hypertrophy on exercise-induced changes in electrocardiographic QRS amplitude

To investigate the effects of volume and pressure overloads and myocardial hypertrophy on exercise-induced changes in QRS amplitude, we reviewed treadmill exercise electrocardiograms. In 10 normal young men, Rv5 amplitude decreased and Sv1 amplitude increased at peak exercise, and returned to the resting value in the recovery period. In 10 patients with aortic regurgitation, Rv5 and Sv1 amplitudes increased after 5 min of recovery. In 12 patients with essential hypertension and 10 with idiopathic hypertrophic non-obstructive cardiomyopathy, Rv5 amplitude remained unchanged or higher at peak exercise compared with the resting value, but patterns of serial changes were similar to that of normal subjects. In 9 patients with atrial septal defect, R'v1 amplitude increased with exercise, whereas it remained unchanged in 12 with isolated complete right bundle branch block. In 5 patients with mitral stenosis, Sv1 amplitude decreased at peak exercise. In conclusion, changes in QRS amplitude with exercise are influenced by hemodynamic abnormality and myocardial hypertrophy, and a major determinant of these serial changes seems to be the change in ventricular volume.

[Effects of typhoon-caused power failure on medical care facilities]

In the evening of September 27, Typhoon 19 passed Yamaguchi prefecture. The wind velocity exceeded anything that the local meteorological observatory has ever recorded so far in this area. When the typhoon was off shore near Yamaguchi prefecture, the gale brought down many electric-light poles around Hofu city with power failure in Hofu city continuing for more than a week. At the same time the total number of emergency patients in Hofu area was the most in the prefecture. Because the power failure continued for many days, there was more indirect damage attributable to this power failure than the damage related directly to the typhoon. The capacity of the emergency electric power generator equipment installed in the Central prefectural hospital in Hofu city is the largest in Yamaguchi prefecture. Even while electric power failed completely in the Hofu city area, treatment of most of the emergency patients at this hospital was possible. There is no hospital that has as large an electric generator as the Central hospital has. Had this typhoon hit in another area, the ensuring confusion which might have occurred at hospitals in that area would have put many patients in danger with the power failure in many hospitals. Power consumption needs in hospitals have increased over that expected on the time the hospital was built. Therefore, the electric power generators installed in hospitals are of the times very small and unable to cope with massive electrical outage.

Renal hypouricemia with both drug-insensitive secretion and defective reabsorption of urate: a novel type of renal hypouricemia

Renal handling of urate in the hypouricemic patient with increase in both urate clearance (Cur) and Cur/creatinine clearance (Ccr) and normal urinary excretion of urate was studied according to the pharmacological evaluation. In the present case there was no response of urate excretion to either pyrazinamide or probenecid. Both furosemide and prednisolone could not alter Cur and Cur/Ccr. Administration of inosine could have increased Cur, which was greater than Ccr. These results suggest that the present case had the defect of both pre- and postsecretory reabsorption of urate, accompanied by the existence of drug-insensitive secretion of urate, which is different from hitherto known types of renal hypouricemia, i.e. a novel type of renal hypouricemia.

Plasma catecholamine responses to dynamic exercise in patients with coronary artery disease--the relationship between sympathetic activity and systolic blood pressure and exercise-induced ventricular arrhythmias

In order to investigate the relationship between sympathetic activity and postexercise systolic blood pressure (SBP) and exercise-induced ventricular arrhythmias in patients with coronary artery disease (CAD), we studied 38 patients and 9 normal subjects who underwent treadmill testing. Peak pressure-rate product was similar in the 2 groups. The plasma concentrations of norepinephrine and epinephrine at rest and immediately after exercise were significantly higher in patients with CAD compared with normal subjects (norepinephrine at rest, p < 0.01; norepinephrine immediately after exercise, p < 0.05; epinephrine at rest, p < 0.05; epinephrine immediately after exercise, p < 0.05). The level of norepinephrine immediately after exercise was significantly higher in 15 patients with a postexercise SBP increase than in 23 patients without that SBP change (p < 0.05), whereas the level of epinephrine was similar in the 2 groups. The level of epinephrine immediately after exercise was significantly higher in 10 patients with exercise-induced premature ventricular contractions than in 28 patients without those arrhythmias (p < 0.05), whereas the level of norepinephrine was similar in the 2 groups. We conclude that a postexercise SBP increase is related to the augmentation of sympathoneural activity and that exercise-induced ventricular arrhythmias are related to the augmentation of sympathoadrenal activity.

Hemodynamic changes during dynamic exercise in patients after mitral valve replacement for chronic mitral regurgitation

To evaluate hemodynamic changes during dynamic exercise, we investigated 13 patients after mitral valve replacement (MVR) for chronic mitral regurgitation (MR) and 5 control subjects by right heart catheterisation during supine bicycle exercise. According to the sizes of the St. Jude Medical (SJM) prosthesis during MVR, patients were divided into group A (n = 8) with SJM 31mm and group B (n = 5) with SJM 29mm. Significant rise in cardiac index (CI) was noted during exercise in both groups A and B (from 3.3 +/- 0.8 to 5.5 +/- 0.9 l/min/m2, p < 0.01 and from 3.0 +/- 0.6 to 5.6 +/- 0.6 l/min/m2, p < 0.01 respectively) and also in control subjects (from 3.4 +/- 0.7 to 6.2 +/- 0.6 l/min/m2, p < 0.01). Mean pulmonary artery and pulmonary capillary wedge pressure were significantly higher during exercise in patients of both groups A and B than control subjects (p < 0.05 and p < 0.01 respectively). Total pulmonary vascular resistance was significantly higher during exercise in both groups A and B than control subjects (p < 0.05 and p < 0.01 respectively). No difference in hemodynamics were noted between the patients of group A and B during exercise. It is concluded that response of CI to exercise in patients after MVR for chronic MR was adequate in comparison to control subjects irrespective of two different valve sizes.

Effect of alacepril on blood pressure and neurohumoral factors at rest and during dynamic exercise in patients with essential hypertension

We assessed blood pressure and neurohumoral factors at rest and during exercise in 10 patients with essential hypertension before and after treatment with the new angiotensin converting enzyme inhibitor, alacepril (25-50 mg day-1). Alacepril significantly lowered mean blood pressure at rest and at the same exercise load as before treatment without affecting heart rate response. The response of plasma renin activity, plasma aldosterone, and plasma adrenaline were not changed by alacepril, but increase of plasma angiotensin II and plasma noradrenaline during exercise were significantly attenuated after alacepril treatment (ANOVA, P = 0.04, both). The change in mean blood pressure during exercise was positively correlated with the decrease in plasma angiotensin II (r = 0.65, P < 0.05). These results demonstrated that alacepril was effective in essential hypertension both at rest and during exercise, suggesting that the antihypertensive effect during exercise might be related to the decrease in pressor hormones, especially in plasma angiotensin II.

Zinc hydroxide stimulates superoxide production by rat alveolar macrophages

The effect of zinc hydroxide on superoxide (O2-) production by rat alveolar macrophages was determined by chemiluminescence and by cytochrome c reduction. Zinc ions had no effect on the chemiluminescence of unstimulated alveolar macrophages. By contrast, zinc hydroxide (ZnOH2), a neutralized form of zinc ions, increased the chemiluminescence level and O2- release. Increased O2- release was inhibited by pertussis toxin, isoquinoline sulfonamide and pretreatment with EGTA. These findings indicate that zinc hydroxide formation from zinc compounds can stimulate the O2- production by alveolar macrophages by receptor-mediated and Ca(2+)-dependent process.