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Biomedical subjects

M Nishikawa

Publications and source records attributed to M Nishikawa.

At least 541 records · Page 30Linked to original sources
PubMed1992

[Involvement of lymph nodes and neural plexus in carcinoma of the pancreas].

We studied 428 lymph nodes attached to the head of the pancreas (13,14,17) in 18 patients with ductal carcinoma of the pancreatic head. These were classified into the small size of the lymph nodes less than 5mm (group S), the moderate size of the lymph nodes (group M) and the large size of the lymph nodes more than 10 mm (group L). The metastases were seen in 76 nodes, which consisted of 49 with group S, 14 with group M and 13 with group L. The lymph node involvement in group (14) S was found in 7 of 18 patients (38.9%), that in group (14) M was in 4 (22.2%) and that in group (14) L was in 2 (11.1%). In these involved cases, the primary tumors tended to be locate in the portion near the superior mesenteric artery, such as in the uncinate process. Invasion of extrapancreatic neural plexus was noted in 9 of 18 patients (50%). There was no significant correlation between nerve plexus invasion and lymphatic invasion by Spearman's rank correlation. In addition, any close relationship between plexus invasion and primary tumor location could not be indicated. These results suggested that neural invasion in pancreatic carcinoma is independent of lymphatic invasion, and the routes of cancer spread via the neural plexus are different from those via the lymphatic vessels. Those without liver metastases survived longer than those with liver metastases, which were characteristically multiple.

Humans↗
PubMed1992

Targeted delivery of human recombinant superoxide dismutase by chemical modification with mono- and polysaccharide derivatives.

Four types of superoxide dismutase (SOD) derivatives such as SOD-carboxymethyl dextran conjugate, SOD-diethylaminoethyl dextran conjugate, galactosylated SOD and mannosylated SOD were synthesized and their potential for selective targeting to organs or cells was evaluated in mice by pharmacokinetic analysis. All SOD derivatives retained 50 to 80% of the original enzymatic activity and were stable during incubation with mouse serum retaining enzymatic activity greater than 80% for 3 hr. After intravenous injection, native SOD was rapidly excreted into urine and no significant accumulation was observed in the organs except the kidney. SOD-carboxymethyl dextran conjugate gave a long plasma half-life because of impaired glomerular filtration and tissue interaction. By contrast, galactosylated-SOD and mannosylated-SOD were very rapidly eliminated from the circulation and taken up by parenchymal and nonparenchymal cells of the liver, respectively, via receptor-mediated endocytosis. These uptake processes were nonlinear and hepatic uptake clearance decreased as the dose increased, although almost complete extraction was obtained at a dose of 0.1 mg/kg. Furthermore, the accumulation in kidney of both glycosylated SODs was drastically decreased due to reduced renal proximal tubular reabsorption and also enhanced hepatic clearance. SOD-diethylaminoethyl dextran conjugate also rapidly disappeared from plasma and distributed into liver, but its accumulation occurred due to electrostatic interaction and was nonspecific in cellular distribution. These results suggest the possibility of controlling the in vivo fate of SOD at a cellular level by chemical modification utilizing sugar moieties with varied physicochemical and/or biological characteristics.

Animals↗
PubMed1992

Drug control policies in some parts of Asia.

The Asian region has experienced drug problems ever since opium was exported to China in the eighteenth century. Today, in some parts of the region, high priority is placed on drug control policies relating, for example, to the eradication of opium poppy cultivation, criminal sanctions against drug trafficking, and treatment programmes for drug-dependent persons. Some good results have been achieved in recent years: according to estimates, opium cultivation in at least one country in the region has decreased; the number of new cases involving drug-dependent persons is falling in a number of countries; and major drug trafficking syndicates have been disbanded.

Asia↗
PubMed1992

[Study on fibrinolysis and platelet function].

The aim of this study is to evaluate the relationship between tissue plasminogen activator (tPA)/PA inhibitor (PAI) complex and PAI, and platelet in the circulating blood. tPA/PAI complex and active PAI (act PAI; Teijin Co., Japan), and PAI antigen (PAI ant; Biopool AB, Sweden) were assayed by enzyme immunoassay (EIA). The mean concentrations (ng/10(9) platelets) in supernatant from lysate of platelet rich plasma (PRP) and washed platelets were 27.1 +/- 9.2, 1.5 +/- 1.2 in tPA/PAI complex, 188.7 +/- 46.1, 83.3 +/- 7.5 in act PAI and 236.2 +/- 41.6, 191.9 +/- 45.1 in PAI ant, respectively. PRP was mixed with ADP (10(-5), 10(-4), 10(-3) M), for 3 min and the supernatant after centrifugation then was provided for assay of PAI and tPA/PAI complex. Concentrations of act PAI, PAI ant and tPA/PAI complex dose-dependently increased with ADP. Almost the same results were obtained, when collagen and other agents were used instead of ADP. This study revealed that platelets contained quantities PAI (as free PAI) and released PAI during aggregation, and that a part of the PAI immediately formed a complex with tPA. Those findings suggested that platelets may play an important role on the formation of thrombus, in the way of anti-fibrinolysis, in addition to novel platelet functions, such as aggregation.

Adult↗
PubMed1992

Purification of rat megakaryocyte colony-forming cells using a monoclonal antibody against rat platelet glycoprotein IIb/IIIa.

We recently reported the production and characterization of four monoclonal antibodies (MoAbs) against rat platelet glycoprotein IIb/IIIa (GPIIb/IIIa). In this study we developed a simple and efficient three-step procedure, based on positive selection by immunoadsorption (panning) using one MoAb, P55, to purify rat megakaryocyte colony-forming cells (megakaryocyte colony-forming units, CFU-MK) from normal bone marrow. Cells obtained after each step were assayed for their ability to form megakaryocyte colonies in the presence of Concanavalin A (Con A)-stimulated rat spleen cell-conditioned medium in soft agar cultures. Marrow cells were first separated on discontinuous Percoll gradients. Cells sedimented at densities between 1.063 and 1.082 g/ml were depleted of cells adherent to plastic tissue culture dishes. The nonadherent cells were further incubated on dishes coated with P55 MoAb. CFU-MK were enriched about 50-fold in the adsorbed cell fraction. This sequential fractionation procedure resulted in a 345-fold (range 276 to 412-fold) enrichment of rat CFU-MK over whole bone marrow cells. The average cloning efficiency of CFU-MK in the final fraction was about 7% (range 5%-9.2%) of the nucleated cells. The overall recovery of CFU-MK averaged 20% (range 9%-29%). The panning step provided a 46-fold enrichment of megakaryocyte burst-forming cells (megakaryocyte burst-forming units, BFU-MK), whose average cloning efficiency in the post-panning fraction was 0.14% (range 0.07%-0.2%). In addition, erythroid burst-forming cells (erythroid burst-forming units, BFU-E) were also significantly enriched by panning, but to a lesser degree than BFU-MK and CFU-MK. By contrast, granulocyte-macrophage colony-forming cells (granulocyte-macrophage colony-forming units, CFU-GM) and erythroid colony-forming cells (erythroid colony-forming units, CFU-E) were not enriched by panning. CFU-MK obtained after panning formed megakaryocyte colonies in the presence of recombinant rat interleukin 3 (rIL-3), mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF), or human erythropoietin (hEPO), as has been reported for murine CFU-MK in whole marrow cells. The highly enriched populations of rat CFU-MK should thus provide a basis for the further study of the regulation of megakaryocytopoiesis.

Animals↗
PubMed1991

Anti-aldosteronergic effect of torasemide.

The diuretic actions of torasemide and furosemide were studied in normotensive rats and in deoxycorticosterone acetate (DOCA)-saline-loaded hypertensive rats. Torasemide (0.3-3 mg/kg) and furosemide (3-30 mg/kg) had a dose-dependent and significant diuretic action in normotensive rats. Potassium retention was only observed in the case of torasemide. Torasemide also had a dose-dependent and significant diuretic action in DOCA-saline-loaded hypertensive rats, whereas furosemide did not. Higher doses of torasemide (10 mg/kg) and furosemide (100 mg/kg) increased both plasma renin activity and aldosterone concentration in normotensive rats in a similar manner. In vivo aldosterone receptor binding was determined to test the possible anti-aldosteronergic effect of torasemide. Torasemide inhibited the binding of aldosterone to its receptor in the cytoplasmic fraction of rat kidney in a dose-dependent manner, while furosemide produced no effect. These results suggest strongly that an anti-aldosteronergic action of torasemide contributes to producing less kaliuresis.

Administration, Oral↗
PubMed1991

Expression of three major protein kinase C isozymes in various types of human leukemic cells.

We examined the levels of protein kinase C (PKC) activity and the expressions of its three major isozymes, designated types I (gamma), II (beta), and III (alpha), in the cytosol and particulate fractions of cells from patients with acute myelogenous leukemia (AML), acute lymphocytic leukemia (ALL), and chronic lymphocytic leukemia (CLL), in an attempt to elucidate the cell type- or lineage-specific expression of these isozymes. The levels of PKC activities in the cytosol and particulate fractions from AML cells were higher than those from ALL or CLL cells. The average PKC activities of AML cells, ALL cells, and CLL cells were 18.7, 12.2, and 11.3 pmol/min/10(8) cells, respectively, in the cytosol fractions and 4.4, 3.1, and 2.6 pmol/min/10(8) cells, respectively, in their particulate fractions. M1 cells (French-American-British classification) and AML cells with T-lymphocyte-associated surface antigens, such as CD2 and CD7, had significantly lower PKC activities among AML cells. Immunoblot analyses using monoclonal antibodies against each isozyme revealed that all three isozymes were broadly distributed on leukemic cells with considerable variability in the level of expression. All lymphoid leukemic cells expressed PKC-gamma in the cytosol fractions, albeit a minor component; however, this type was observed in cells from only half the number of AML patients. Those AML cells with cytosolic PKC-gamma usually expressed lymphoid surface antigens, such as CD2, CD7, and CD19. On the other hand, cytosolic PKC-beta and PKC-alpha were commonly observed in all types of leukemic cells. AML cells expressed these two types at almost equal levels, but in lymphoid cells, expressions of PKC-beta were usually more abundant than those of PKC-alpha. These data suggest that AML cells with lymphoid antigens might have a lower PKC activity but more predominant expression of cytosolic PKC-gamma than the usual AML cells.

Adult↗
PubMed1991

Effects of actinomycin D on airway constriction induced by tachykinins and capsaicin in guinea-pigs.

The effects of actinomycin D on airway constriction induced by tachykinins was studied in guinea-pigs in vitro and in vivo. Actinomycin D significantly inhibited the constriction of isolated guinea-pig trachea induced by neurokinin A (NKA) and eledoisin. Conversely, substance P (SP)- and physalaemine-induced constrictions were not affected by actinomycin D. The same selectivity in the inhibitory action of actinomycin D against tachykinins was also observed in in vivo. Actinomycin D given i.v. specifically inhibited the increase in airway resistance induced by NKA. I.v. injection of NKA caused not only airway constriction but also transient systemic hypotension. Interestingly, actinomycin D injected i.v. inhibited only airway constriction and the systemic hypotension induced by NKA was not affected. These results clearly suggest that actinomycin D specifically inhibits NKA-induced airway constriction in guinea-pigs. Actinomycin D also had an inhibitory action on the airway constriction induced by capsaicin. In the case of capsaicin-induced constriction, actinomycin D was more effective on the later phase of constriction than on the acute phase. The airway constriction induced by capsaicin is thought to be mediated by the release of SP and NKA from sensory nerve endings, and the persistent increase in airway resistance induced by capsaicin is thought to be due mainly to NKA.

Airway Resistance↗
PubMed1991

[Dynamic MRI of hepatocellular carcinoma with portal vein tumor thrombus].

Dynamic MRI with injection of Gd-DTPA was performed in 7 patients with hepatocellular carcinoma associated with portal vein tumor thrombus. A portal vein tumor thrombus was clearly visualized as a low intense structure. The segment supplied with this portal vein shows high intensity, probably due to the decrease in portal blood flow and compensated arterial blood flow. A tumor itself, located in this segment, was shown as a low intense area. Thus dynamic MRI is a useful method for differentiating the tumor from the surrounding nontumorous tissue with decrease in portal flow.

Aged↗
PubMed1991

Dynamic fluctuations in blood of thrombin/antithrombin III complex (TAT).

The dynamic fluctuation of thrombin-antithrombin III complex (TAT) was studied in blood obtained during the daytime (at 9 AM, noon, 3 PM), during extracorporeal circulation and during the course of disseminated intravascular coagulation (DIC), to certify whether the level of TAT in blood can reflect the generation of thrombin. In 10 healthy male volunteers, the mean values of TAT (micrograms/liter) were 1.74 (+/- 1.36) at 9 AM, 1.22 (+/- 0.47) at noon, and 1.25 (+/- 0.68) at 3 PM. TAT did not show a daytime fluctuation, unlike fibrinolytic factors. The mean values of TAT in 38 hemodialyzed patients were 4.83 (+/- 2.8) before the initiation, 6.59 (+/- 4.39) in the first hour, and 13.42 (+/- 10.96) at the end of a dialysis session. In 20 patients undergoing open heart surgery, the mean value of TAT was increased during cardiopulmonary bypass (CPB) and decreased with time after the end of surgery. The fibrinopeptide A (FPA) value was increased with TAT during CPB but achieved a maximum level immediately after heparin neutralization by protamine. In 20 patients with DIC, the values of TAT varied from 5.8 to 297 micrograms/liter in the blood at the onset of DIC. In seven of eight patients treated with low-molecular-weight heparin (LMW-H), the values of TAT and FPA were lower 24 hr after LMW-H than before the treatment. These results suggest that the level of TAT in blood reflected the formation of thrombin and could serve as a sensitive parameter of activated coagulation in circulating blood.

Adult↗
PubMed1991

The prevalence at birth of cogenital malformations at a maternity hospital in Osaka City, 1948-1990.

The frequencies of congenital malformations at St. Barnabas' Hospital, Osaka were studied during the period 1948-1990. There were 1,418 malformed infants diagnosed during the first week of life among a total number of 131,996 births during the period. Of the 1.07% of malformed children, 0.90% had single and 0.17% had multiple malformations. The birth prevalence was 1.07% in singletons and 1.20% in twins. There was significant difference in prevalence between males (1.15%) and females (0.97%). The prevalence was 0.88% for the period 1948-1958 and increased with each year cohort up to the recent period when the value was 1.38%. Varus deformities of feet was the most common defect (23.4 per 10,000 births), followed by polydactyly (finger) (7.8), anencephaly (7.1), cleft lip and palate (6.5), syndactyly (toe) (6.5), cleft lip (6.3), and Down's syndrome (6.1). The prevalence of conjoined twins was 1 in 65,551 deliveries. Significant differences occurred between males and females for cleft palate, cleft lip and palate, syndactyly (finger), oligodactyly (finger), and hypoplastic auricle. The prevalences for valgus deformities of feet, syndactyly (toe) and atresia ani increased significantly with the year cohort, whereas the prevalence of cleft palate decreased significantly with the year cohort. Overall prevalence was significantly higher in 1970-1990 (1.28% than in 1948-1969 (0.88%). Similar results were examined for cleft lip and palate, syndactyly (finger), syndactyly (toe), hypospadias, hydrocele testis, and Down's syndrome.

Congenital Abnormalities↗
PubMed1991

Possibility of ideal blood glucose control by a new oral hypoglycemic agent, N-[(trans-4-isopropylcyclohexyl)-carbonyl]-D-phenylalanine (A-4166), and its stimulatory effect on insulin secretion in animals.

N-[(trans-4-isopropylcyclohexyl)-carbonyl]-D-phenylalanine (A-4166) revealed a new mode of hypoglycemic action with a more rapid onset and a shorter duration of action than the sulfonylureas (SUs). Hypoglycemic mechanisms and glycemic control benefits were demonstrated in laboratory animals. The stimulatory effect of A-4166 on insulin release, in fasting dogs with a cannula into the portal vein, was more rapid than that of tolbutamide after oral administration. A-4166 stopped the stimulation of insulin secretion very quickly, whereas tolbutamide maintained an elevation in plasma insulin levels for at least 6 hours. In the case of A-4166, a counter-regulatory glucagon response was observed during recovery from hypoglycemia, but it was significantly inhibited by tolbutamide. Hyperglycemia induced by glucose loading was rapidly inhibited by A-4166 in normal rats, in genetically diabetic KK mice and in STZ-induced non-insulin-dependent diabetes mellitus (NIDDM) rats. Also, repeated administration of A-4166 for 2 weeks enhanced insulin secretion in the same manner as a single administration in normal rats. In conclusion, A-4166 is a new type of oral hypoglycemic agent, having a rapid and short-term insulin secretory effect and no suppressive effect on the hypoglycemia-induced glucagon response. Oral therapy with A-4166 would be beneficial in supplementing endogenous insulin secretion and would exert ideal glycemic control in NIDDM patients.

Animals↗
PubMed1991

Analysis of methylbenactyzium bromide in human urine by thin-layer chromatography and pyrolysis gas chromatography.

A rapid and simple method of utilizing thin-layer chromatography (TLC) and pyrolysis gas chromatography (PyGC) for the identification and determination of methylbenactyzium bromide in human urine was studied in this report. Methylbenactyzium bromide was extracted from urine with ODS-cartridge (Sep-Pak C18), then spotted onto a silica gel 60 F254 TLC plate. After development, the separated spot of methylbenactyzium bromide was scraped and wrapped with a ferromagnetic foil without extraction by any organic solvents. The sample was applied into PyGC analysis. The optimum temperature for pyrolysis was 590 degrees C. The main degradation product of methylbenactyzium bromide was identified as diphenylmethane in this procedure by gas chromatography/mass spectrometry (GC/MS). A calibration graph prepared by absolute calibration method showed a good linearity over the concentration range of 1-75 micrograms/spot for methylbenactyzium bromide. The coefficient of variation obtained for eleven replicate analyses of the 3 micrograms/spot of standard methylbenactyzium bromide was 3.8%. The detection limit of this compound by this procedure was 0.1 micrograms/spot.

Calibration↗
PubMed1991

Plasma gastrin and cholecystokinin response after pylorus-preserving pancreatoduodenectomy with Billroth-I type of reconstruction.

Plasma gastrin and cholecystokinin (CCK) responses were measured after a pancreatoduodenectomy (PD) using the Billroth-I type reconstruction combined with distal partial gastrectomy (standard PD) and combined with preservation of the pylorus and the duodenal bulb (PPPD). Six unoperated patients, 4 men and 2 women, were studied as control subjects. Basal plasma levels of gastrin were significantly higher in controls than in patients who had a standard PD (p less than 0.05) and gastrin responses to a meal were also blunted in these patients. In contrast basal and postprandial levels of gastrin after PPPD were significantly higher than these found in patients with standard PD (p less than 0.05). Postprandial gastrin response after PPPD were similar in pattern to these found in controls. Integrated gastrin release after PPPD was less than that of the control but was significantly greater than that in patients with standard PD. Basal plasma levels of CCK in the patients after the standard PD were significantly lower than in controls and significantly higher postprandial levels of CCK were found after PPPD compared to standard PD (p less than 0.05). However integrated CCK from 0 to 120 minutes were not significantly different between PPPD and standard PD groups. Based on these observations concerning hormonal release of gastrin and CCK, preservation of the stomach and the duodenal bulb appears to be a more physiologic reconstructive procedure than the standard PD. In addition the operation probably has more beneficial effect on the injured pancreas in time.

Adolescent↗
PubMed1991

Therapeutic trial of hematological disorders with intermittent administration of high-dose 1-alpha-hydroxyvitamin D3.

Aplastic anemia and myelodysplastic syndrome were successfully treated with an intermittent administration of high-dose 1 alpha-hydroxy-vitamin D3, an active analogue of 1,25-dihydroxyvitamin D3. This effect was considered to be through the differentiation-inducing and immunomodulatory actions of 1,25-dihydroxyvitamin D3. The only adverse effect was hypercalciuria which was controllable by decreasing the dose.

Adult↗
PubMed1991

Iodothyronine 5'-deiodinase activity in cultured rat myocardial cells: characteristics and effects of triiodothyronine and angiotensin II.

Using a primary culture of neonatal rat heart, we investigated the properties of iodothyronine 5'-deiodinating activity in the heart. 125I- release from [125I] reverse T3 incubated with cell homogenates depended on the concentrations of protein and dithiothreitol, pH, incubation time, and temperature of the incubation mixture. The activity was almost completely inhibited by 10(-3)-10(-5) M propylthiouracil and had the higher affinity for reverse T3 than T4. These findings indicate that type I iodothyronine 5'-deiodinase(I-5'-D) exists in cultured neonatal rat myocardial cells. Then, we studied the direct effects of T3, insulin, glucocorticoid, and angiotensin II (AII) on myocardial I-5'-D. The addition of 10(-9)-10(-7) M T3 or 10(-9)-10(-6) M AII to the culture medium increased I-5'-D activity in a dose-dependent manner. Insulin and dexamethasone, however, had no significant effects. Kinetic studies revealed that maximum velocities in T3- and AII-treated cells were 2.1- and 1.8-fold above the control value, respectively, whereas the apparent Michaelis-Menten constant did not alter significantly both in T3- and AII-treated cells. Moreover, the treatment of cyclohexamide combined with T3 or AII completely abolished the stimulating effect of these agents on I-5'-D activity. From these data, it is suggested that both T3 and AII increase the activity of myocardial I-5'-D by their direct actions to the heart, probably through the new synthesis of I-5'-D.

Angiotensin II↗