Expression level of P2X7 receptor is a determinant of ATP-induced death of mouse cultured neurons.

Activation of P2X7 receptor (P2X7R), a purinergic receptor, expressed by neurons is well-known to induce their death, but whether or not their sensitivity to ATP depends on its expression levels remains unclear. Here, we examined the effect of the expression level of P2X7Rs on cell viability using pure neuron cultures, co-cultures with astrocytes derived from SJL- and ddY-strain mice, and mouse P2X7R-expressing HEK293T cell systems. Treatment of pure neuron cultures with 5mM ATP for 2h, followed by 3-h incubation in fresh medium, resulted in death of both types of neurons, and their death was prevented by administration of P2X7R-specific antagonists. In both SJL- and ddY-neurons, ATP-induced neuronal death was inhibited by a mitochondrial permeability transition pore inhibitor cyclosporine A, mitochondrial dysfunction being involved in their death. The ATP-induced neuronal death was greater for SJL-neurons than for ddY-ones, this being correlated with the expression level of P2X7R in them, and the same results were obtained for the HEK293T cell systems. Co-culture of neurons with astrocytes increased the ATP-induced neuronal death compared to the case of pure neuron cultures. Overall, we reveal that neuronal vulnerability to ATP depends on the expression level of P2X7R, and co-existence of astrocytes exacerbates ATP-induced neuronal death.

Different effects of low and high doses of endothelin on haemodynamics and hormones in the normotensive conscious dog.

The effects of low-dose endothelin on systemic haemodynamics and vasoactive hormones were examined in conscious dogs. In addition, we examined the effects of endothelin on pressor responses to noradrenaline and angiotensin II and the baroreflex regulation of heart rate in conscious dogs. Continuous infusion of 40 fmol/kg per min endothelin for 40 min induced a mild but significant reduction in mean arterial pressure from 89.1 +/- 1.7 to 82.7 +/- 2.0 mmHg (P less than 0.05), associated with decreases in total peripheral resistance 20 min later. A 400 fmol/kg per min dose of endothelin, on the other hand, induced a gradual elevation of mean arterial pressure from 89.2 +/- 2.3 to 96.8 +/- 2.0 mmHg (P less than 0.05), associated with increases in total peripheral resistance over 30 min. The 40 fmol/kg per min dose of endothelin infusion induced a significant reduction in plasma arginine vasopressin (AVP; P less than 0.05) and elevations of plasma atrial natriuretic peptide (ANP; P less than 0.05), plasma prostaglandin E2 (PGE2; P less than 0.05) and plasma 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha; P less than 0.05). The 400 fmol/kg per min dose produced elevations of AVP, ANP, PGE2 and 6-keto-PGF1 alpha (P less than 0.05). Pressor responses to noradrenaline and angiotensin II were significantly attenuated during continuous infusion of 40 fmol/kg per min endothelin, whereas 400 fmol/kg per min endothelin did not induce any significant changes compared with the control. Furthermore, baroreflex sensitivity was attenuated with 40 fmol/kg per min endothelin but did not show any significant changes at 400 fmol/kg per min.(ABSTRACT TRUNCATED AT 250 WORDS)

Depressor systems contribute to hypertension induced by glucocorticoid excess in dogs.

OBJECTIVE: The aim of this study was to investigate the role of depressor systems in glucocorticoid-induced hypertension. METHODS: The serial changes in cardiorenal hemodynamics, urinary excretions of kallikrein and prostaglandins (PGE2 and the prostacyclin derivative 6-keto-PGF1 alpha) before, and during the administration of both low and high doses of dexamethasone (9 alpha-fluoro-16 alpha-methylprednisolone) and after the cessation of dexamethasone were examined in conscious trained dogs. In addition, pressor responses to prostaglandin, bradykinin, bradykinin antagonist and indomethacin were studied during the administration of dexamethasone. RESULTS: High-dose dexamethasone induced a significant elevation in mean arterial pressure (MAP) that was accompanied by a significant reduction in the urinary excretion of kallikrein, PGE2 and 6-keto-PGF1 alpha. In contrast, low-dose dexamethasone treatment had no significant effect upon MAP but induced a transient elevation in the urinary excretion of kallikrein, PGE2 and 6-keto-PGF1 alpha. Furthermore, additional oral administration of indomethacin produced a significant elevation in MAP in dogs treated with low-dose dexamethasone; but did not affect the hemodynamics of animals with high-dose dexamethasone. Whilst i.v. administration of either bradykinin or prostacyclin induced a significant reduction in MAP in high-dose but not low-dose dexamethasone-treated dogs, administration of a competitive bradykinin antagonist, D-Arg-[Hyp3, Thi5,8, D-Phe7]-bradykinin induced a significant elevation in MAP in low-dose but not high-dose dexamethasone-treated dogs. CONCLUSION: Depressor systems play an important role in regulation of blood pressure in glucocorticoid-treated dogs.

Clinical economics in clinical trials: the measurement of cost and outcomes in the assessment of clinical services through clinical trials.

As the population ages and more expensive high-technology services become available, health care costs continue to spiral upward. Because the financial resources for health care are limited, economic analysis can help to evaluate expenditures and set priorities. Economic analysis of medical technology or medical care evaluates a medical service by comparing its dollar cost with its dollar benefit (cost-benefit), by measuring its dollar cost in relation to its outcomes (cost-effectiveness) as well as in relation to its utility or quality-adjusted outcomes (cost-utility), or simply by tabulating the costs involved (cost-identification). Direct costs are generated as services are provided. In addition, patients' productivity is affected, and these costs can be considered, especially in determining the benefit of a service that decreases morbidity or mortality. Intangible costs are those of pain, suffering, and grief. The point of view, or perspective, of the study determines the costs and benefits that will be measured in the analysis. Sensitivity analysis, which can evaluate the stability of the conclusions to the data used, is an important assessment within economic analysis. Economic analysis of new pharmaceutical therapies is increasingly being incorporated into clinical trials. Although there are some limitations of pharmacoeconomic information in clinical studies of drug safety and efficacy, these trials are often the only opportunity for economic data collection before adoption and reimbursement decisions are made. Validation after the drug has been introduced should complement economic information developed from clinical trials.

Angiotensin-converting enzyme inhibitors and probucol suppress the time-dependent increase in urinary Type IV collagen excretion of Type II diabetes mellitus patients with early diabetic nephropathy.

BACKGROUND: A multicenter prospective clinical trial was carried out in 9 National Hospitals in Japan to elucidate the time-dependent change in urinary Type IV collagen excretion rate of Type II diabetes mellitus (DM) patients, and to investigate whether an angiotensin-converting enzyme inhibitor (ACE-I) or probucol is effective in preventing progression of renal involvement of diabetics by evaluating urinary Type IV collagen excretion. METHODS: Normo- and microalbuminuric patients with Type II DM were recruited. Patients were assigned to either the control (n = 88), ACE-I (n = 43) or probucol (n = 37) group and treated for 24 months. Besides albumin excretion rate (AER), urinary Type IV collagen excretion rate was also measured. RESULTS: Although, AER, urinary N-acetyl-beta-D-glucosaminidase and beta2-microglobulin excretion rates in the control group did not vary over 24 months, urinary Type IV collagen excretion rate in the control group increased time-dependently (p < 0.01 vs baseline at 18 months and p < 0.005 vs baseline at 24 months). In the ACE-I and probucol groups, time-dependent increases in urinary Type IV collagen excretion rates were not observed. In the ACE-I group, the urinary Type IV collagen excretion rate was significantly lower than that in the control group at 24 months (p < 0.05). In the probucol group, the urinary Type IV collagen excretion rate was significantly lower than that in the control group at 6 months (p < 0.05). In the ACE-I group, AER decreased significantly compared with baseline at 18 months (p < 0.05) and at 24 months (p < 0.005). CONCLUSIONS: ACE-I has a beneficial effect and probucol may have a beneficial effect in preventing the progression of early diabetic nephropathy. Measurement of the urinary Type IV collagen excretion rate in combination with AER would be useful for the management of early renal involvement in Type II DM.

Adult T-cell leukemia with hypercalcemia-induced metastatic calcification in the lungs due to production of parathyroid hormone-related protein.

A 60-year-old man was diagnosed as adult T-cell leukemia with severe hypercalcemia because of production of parathyroid hormone-related protein. After admission, the patient had respiratory insufficiency with an infiltrative shadow in his lungs suggestive of pneumonia. However, neither improvement in respiratory function nor disappearance of the abnormal chest shadow was observed with administration of various antibiotics. An autopsy demonstrated the chest shadow had been caused by metastatic calcification associated with hypercalcemia due to production of parathyroid hormone-related protein. The possibility of metastatic calcification should be considered in patients with adult T-cell leukemia and hypercalcemia who have an abnormal chest shadow.

IgA nephropathy associated with portal hypertension in liver cirrhosis due to non-alcoholic and non-A, non-B, non-C hepatitis.

A 69-year-old female was admitted to our hospital because of leg edema, proteinuria (2.1 g/day), and gross hematuria. She had non-alcoholic liver cirrhosis of unknown etiology. Esophageal varices also were found. Examination of the renal biopsy specimen revealed mesangial proliferative glomerulonephritis with IgA deposits. Propranolol was administered orally to reduce portal hypertension, resulting in a progressive decrease in urinary microalbumin excretion. This case suggests that portal hypertension is involved in the pathogenesis of IgA nephropathy in liver cirrhosis.

Effects of methyl-group acceptors on the regulation of plasma cholesterol level in rats fed high cholesterol diets.

The effects of methyl-group acceptors such as glycine, guanidinoacetic acid, and nicotinamide on cholesterol metabolism and phosphatidylcholine(PC) biosynthesis were investigated with rats fed a 25% casein diet containing cholesterol with or without methionine supplement. The effect of ethanolamine, an indirect methyl-group acceptor via phosphatidylethanolamine(PE) formation, was also compared with those of methyl-group acceptors. The methyl-group acceptors and ethanolamine decreased or tended to decrease plasma total cholesterol level when added to the 25% casein diet. These compounds also significantly depressed the methionine-induced enhancement of plasma cholesterol level. The activity of PE N-methyltransferase was decreased by the addition of glycine, guanidinoacetic acid, and nicotinamide, but not ethanolamine, to the reaction mixture when assayed using the postmitochondrial fraction of liver homogenate, suggesting that PE N-methyltransferase activity can be depressed by glycine N-methyltransferase, guanidinoacetic acid N-methyltransferase, and nicotinamide N-methyltransferase systems. The PE N-methyltransferase activity in liver microsomes, however, did not decrease in response to the dietary addition of methyl-group acceptors. The in vitro incorporation of [CH3-14C]methionine into PC of liver slices was also significantly inhibited by the addition of glycine and nicotinamide, but not guanidinoacetic acid and ethanolamine, to the incubation medium. It is suggested that methyl-group acceptors can decrease plasma cholesterol level at least in part through the depression of PC biosynthesis via PE N-methylation pathway, and that the mechanism for the plasma cholesterol-lowering effect of ethanolamine is different from that of methyl-group acceptors.

[Transfer of cefmenoxime to lung tissue and thoracic muscle in thoracic surgery].

Twenty patients who were performed pulmonary resection for the disease of the lung were administered 2 g of cefmenoxime (CMX) intravenously during the operation. The CMX levels in serum, lung tissue and thoracic muscle were measured by agar-well technique. The CMX levels in lung tissue and thoracic muscle were higher than the MIC80 of CMX for Klebsiella pneumoniae, Haemophilus influenzae and Streptococcus pneumoniae which were commonly as isolated causative organisms from the patients with pulmonary infection. These results indicate that CMX will be useful agent for the prevention and treatment of pulmonary infection.

Clinicopathologic features of local and metastatic recurrences in primary lung adenocarcinoma.

We attempted to construct the contour of recurrence in primary lung adenocarcinoma with clinicopathologic variables based on data of 131 patients with completely resected primary lung adenocarcinoma. In univariate analysis, tumor size (more or less 3 cm in diameter), p-T, p-N, pathological stage, differentiation, ly factor and v factor were chosen for prognostic predictors. In multivariate analysis, v factor and p-N were independent variables of local recurrence and metastatic recurrence, respectively. The examination of significant correlation among clinicopathologic variables in terms of 5-year survival rates of patients showed that tumor size, p-T, ly factor and v factor were profoundly related to local recurrence, whereas ly factor, differentiation and p-N were linked to distant metastasis. We therefore examined an additive effect of tumor size, differentiation and vascular invasion on recurrence. The results demonstrated that neither local nor metastatic recurrences were found in patients with well differentiated adenocarcinoma less than 3 cm in diameter if vascular invasion was negative. We conclude that vascular (ly factor and v factor) is central to lung adenocarcinoma recurrence. The vascular invasion is a powerful predictor of recurrence in less than 3 cm diameter, well differentiated adenocarcinoma of the lung.

[Rhabdomyolysis related-acute renal failure in a patient with hyperosmolar nonketotic diabetic coma (HNKC): demonstration of myoglobin casts after normalization of renal function].

We report a patient with rhabdomyolysis secondary to hyperosmolar nonketotic diabetic coma (HNKC), who progressed to acute renal failure. A 43-year-old male with diabetes mellitus for three years was admitted to our hospital because of loss of consciousness. The laboratory findings at admission were as follows: serum glucose 1792 mg/dl, serum Na 129 mEq/1, BUN 71 mg/d1, serum creatinine 3.3 mg/d1, CPK 715 IU/1, plasma osmolality 370 mOsm/1, and negative urine ketone bodies. A diagnosis of HNKC was made. On the 2nd day, he had oliguria and the serum creatinine increased despite adequate treatment of HNKC by the administration of intravenous fluid and insulin. On the 4th day, CPK reached 47,300 IU/1, and serum myoglobin was also increased, indicating rhabdomyolysis. His renal function improved gradually and was almost normalized on the 20th day. Renal biopsy on the 23rd day showed myoglobin at the distal renal tubules, which appeared to be involved in the pathogenesis of renal failure by rhabdomyolysis. However, we found little abnormality association with diabetic nephropathy in the renal tissue. Since HNKC is known to induce acute renal failure rarely without diabetic nephropathy, these findings suggested that the acute renal failure was caused mainly by the rhabdomyolysis. Acute renal failure induced by rhabdomyolysis in patients with HNKC is rare, but fatal. The present study showed that the measurement of serum CPK and urine myoglobin was helpful for early diagnosis. Only 12 cases have been reported to have developed renal failure due to rhabdomyolysis among patients with HNKC. To our knowledge, we demonstrated for the first time that myoglobin at the distal renal tubules after renal function was normalized.

[Reduced operation for rectal cancer].

The effectiveness of extended dissection of higher-ranked lymph nodes in patients with rectal cancer has been well recognized recently. However, to prevent postoperative bladder and sexual dysfunction, reduced lymphadenectomy and autonomic nerve preservation are necessary. By definition a reduced operation for rectal cancer attempts to preserve the autonomic nerve and the levator ani muscles without hampering recovery. To clarify the indication of reduced operation for rectal cancer, 219 patients with rectal cancer who underwent resections at our hospital between 1980 and 1986 were analyzed. The relationship of the depth of tumor invasion through the bowel wall to lymph node metastasis in rectal cancer was examined. In cases of rectal cancer limited to submucosa or muscularis propria, the degree of metastatic spread was n0 or n1 (+). In the cases of rectal cancer invading subserosa, serosa or contiguous structures, the degree of metastatic spread was n3(+) or n4(+). Concerning the relationship of the histopathological type and 5-year survival rate, the corrected 5-year survival rate was 72.46% in cases of well and moderately differentiated adenocarcinoma, and 48.84% in cases of poorly differentiated adenocarcinoma and undifferentiated carcinoma. From these results, reduced lymph node dissection and autonomic nerve preservation are possible in patients with well and moderately differentiated adenocarcinoma with invasion into the mucosa, submucosa and muscularis propria.

[Evaluation of chemotherapy with docetaxel and cisplatin in advanced non-small cell lung cancer].

Clinical study has been conducted to evaluate the efficacy of chemotherapy with docetaxel and cisplatin in six patients with advanced non-small cell lung cancer. Treatment schedule consisted of docetaxel 60 mg/m2 and cisplatin 80 mg/m2 on day 1 and repeated every 4 weeks. Eligible patients had histologically proven locally advanced or metastatic non-small cell lung cancer, PS < or = 2, age < or = 74, normal hematological, hepatic and renal functions and informed consent in writing. Six patients have been included; all were males, median age 64 (range 47-74), histology; adenocarcinoma 4, squamous cell carcinoma 2, stage III B 4, stage IV 2. Among these 6 patients, 3 PR (50%) were observed. Neutropenia was the most common adverse event (83%). The lowest granulocyte counts were most frequently seen on day 9.4 (range: 6-14). Non hematologic adverse events included alopecia (6 cases), general fatigue (5 cases), anorexia (5 cases) and emesis (3 cases). These events were recovered rapidly with no therapy. The results suggest that combination chemotherapy of docetaxel and cisplatin will be effective and safe under careful observation.

[A study of the right ventricular load at the unilateral pulmonary artery occlusion test after pneumonectomy].

After pneumonectomy, it is recognized that the absolute reduction of the pulmonary vascular bed makes the right ventricular afterload increase and can cause right heart failure in patients with low cardiopulmonary reserve. Therefore, we investigated how the right ventricular load was predicted by UPAO test, comparing hemodynamics at the time of the test with those after pneumonectomy in patients with lung cancer. At the test, the absolute reduction of the pulmonary vascular bed made the right ventricular afterload increase but the right ventricular pump function was maintained at the preoperative level by the increase of the right ventricular work load, namely, by the contraction of the right ventricle. After pneumonectomy, the absolute reduction of the vascular bed did not always make the afterload increase and in spite of the decreased preload the pump function was maintained at the preoperative level by increased heart rate. Additionally, the increase of the right ventricular work load improved during early postoperative days. It was concluded that UPAO test was apt to overestimate the right ventricular load of the postoperative day because it was done under the condition of the different compensatory function from the postoperative hypovolemic change.

Early vitamin K deficiency bleeding in a neonate associated with maternal Crohn's disease.

We report herein a case of early vitamin K deficiency bleeding (VKDB) in a neonate associated with maternal Crohn's disease. A female neonate was born at 37 weeks' gestation and weighed 2778 g. She developed broad purpura on her back on day 1. Laboratory data showed anemia, prolonged coagulation time and elevated protein induced by vitamin K absence or antagonist-II. Early VKDB has not been reported in a neonate born from mother with active Crohn's disease. It is essential to give vitamin K selectively as soon as possible after birth to prevent early VKDB in neonates.

Primary erythrocytosis in a Japanese black calf: a case report.

An 8-month-old Japanese Black heifer with severe erythropoietic symptoms was subjected to clinical, histological and cytological examinations. During the 1 month clinical observation period, severe increases in RBC count, packed cell volume and haemoglobin concentration were observed. The plasma erythropoietin (Epo) concentration of the heifer (20.7 mIU/ml) was similar to that observed in normal control heifers. Blood gas examinations of the arterial and venous blood revealed low levels of partial pressure O(2) (PaO(2)), partial pressure CO(2) (PaCO(2)) and O(2) saturation (SaO(2)), while the blood pH was within the normal range. Gross lesions could not be detected. However, microscopic observation revealed severe proliferation of erythroblasts in the bone marrow and in the spleen without evidence of neoplastic changes. Based on these clinical and pathological examinations, we diagnosed the heifer as being the first case of primary erythrocytosis in Japanese Black cattle.

The influence of dietary protein on the synthesis of vasoactive substances in subtotally nephrectomized spontaneously hypertensive rats.

The effects of dietary protein alterations on the synthesis of prostaglandins and kallikrein were examined in subtotally nephrectomized spontaneously hypertensive rats. Three diets containing 40, 24 and 8% protein were prepared. After subtotal nephrectomy, rats were given one of the three diets for the next 12 weeks. During the study, systolic blood pressure, urinary excretions of protein, 6-keto-prostaglandin F1 alpha, thromboxane B2 and kallikrein were measured every 2 weeks. Although the diets did not prevent the further elevation of systolic blood pressure, the rats on the low protein diet displayed lower serum creatinine levels and urinary protein levels. The urinary excretion of thromboxane B2 was unaffected by the amount of dietary protein, but the urinary excretion of 6-keto-prostaglandin F1 alpha was lower in the low protein diet group. Furthermore, the urinary excretion of kallikrein increased significantly in rats on high protein diet. These results suggest that manipulation of dietary protein may alter the natural course of renal failure induced by subtotal nephrectomy in spontaneously hypertensive rats.

Differences in the effects of angiotensin converting enzyme inhibitors with or without a thiol group in chronic renal failure in rats.

1. We have investigated the effects of the non-renin-mediated actions of angiotensin converting enzyme inhibitors on the progression of chronic renal failure accelerated by hypertension. For this purpose, we studied the effects of captopril (a thiol-containing angiotensin converting enzyme inhibitor), enalapril (an angiotensin converting enzyme inhibitor without a thiol group) and cysteine (a thiol-containing amino acid which has no angiotensin converting enzyme-inhibitory action) in adriamycin-treated rats with deoxycorticosterone acetate-salt hypertension, in which the renin-angiotensin system was suppressed. 2. There were no significant differences in blood pressure between these groups and the control group [adriamycin-treated group with deoxycorticosterone acetate-salt loading, 206 +/- 7 mmHg (27.4 +/- 0.9 kPa) at week 10]. 3. Massive proteinuria occurred in all groups. At the end of the experiment (at week 10), urinary protein excretion was significantly reduced in the captopril and cysteine groups compared with the control group. No manifest improvements appeared in the enalapril group. 4. Levels of serum creatinine and blood urea nitrogen increased progressively. At week 10, the increases in the serum levels of creatinine were less in the captopril (87 +/- 16 mmol/l) and cysteine (80 +/- 19 mmol/l) groups than in the control group (124 +/- 27 mmol/l) (P less than 0.01). No marked differences were found between the control and enalapril groups. 5. Captopril and cysteine caused more than a three-fold reduction in the focal glomerulosclerosis score when compared with that in the control group, but enalapril did not decrease the score. The extent of tubulointerstitial change was parallel with the focal glomerulosclerosis score. 6. We conclude that the thiol group is possibly involved in the mechanism of the beneficial effects of some angiotensin converting enzyme inhibitors on the progression of chronic renal failure exacerbated by hypertension.