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Y Hatano

Publications and source records attributed to Y Hatano.

At least 109 records · Page 6Linked to original sources
PubMed1994

Barbiturates inhibit endothelium-dependent and independent relaxations mediated by cyclic GMP.

The inhibitory effects of volatile and local, but not intravenous, anesthetics on endothelium-dependent relaxations of blood vessels have been demonstrated in vitro by several investigators. The aim of this study was to determine the effects of barbiturates on endothelium-dependent arterial relaxation and elucidate the mechanism(s) responsible. Canine mesenteric arteries and rat aortae were isolated, and tension changes in helical strips were recorded. Endothelium-dependent relaxations elicited by acetylcholine and bradykinin in canine mesenteric arteries, and those by acetylcholine in rat aortae, were significantly attenuated by thiopental (3 x 10(-4) M) pretreatment. Sodium nitroprusside (SNP)-induced, endothelium-independent relaxations were significantly attenuated by thiopental (10(-4)-3 x 10(-4) M). The effects of pentobarbital were less marked than those of thiopental. Acetylcholine (10(-5) M)-stimulated levels of 3',5'-cyclic guanosine monophosphate (cGMP) in rat aortae were reduced significantly by thiopental and pentobarbital (both 10(-3) M), and SNP (3 x 10(-7) M)-stimulated levels were reduced by thiopental (3 x 10(-4)-10(-3) M) and pentobarbital (10(-3) M). We conclude that barbiturates inhibit cGMP-mediated endothelium-dependent and independent arterial relaxations. Inhibition of endothelium-dependent relaxation by barbiturates may be mediated by their effects on vascular smooth muscle itself and not on endothelium.

Acetylcholine↗
PubMed1994

[A study of prostatic tissue levels of cefodizime (CDZM)].

Twenty-four patients suffering from prostate hyperplasia were given venous injections of CDZM of either 1 or 2 g at specific intervals (30 min, 1, 2 and 4 hr) before surgery. Blood samples from the injected vein and tissue samples from the prostate were subsequently taken. In this study, the concentrations of CDZM in the prostate tissue (P) and in serum (S), as well as the ratio of the tissue to serum concentrations (P/S) were determined. In patients given 1 g injections, P ranged from 5.26-48.10 micrograms/g, while S ranged from 25.40-130.00 micrograms/ml and P/S ranged from 12.6-37.0%. In the patients given 2 g injections, P ranged from 9.40-49.20 micrograms/g, S ranged from 62.30-234.00 micrograms/ml and P/S ranged from 9.3-29.1%. CDZM exhibited excellent transmigration to the prostate tissue. Inflammatory bacteria present in prostatitis and urinary tract infections are generally those of E. coli, Proteus sp., but because the P range was much higher than the ratio of MIC, CDZM is expected to be useful against infections in the field of urology.

Aged↗
PubMed1994

[A study on evaluation of CBF measurement based on microsphere model with N-isopropyl-p-[123I]iodoamphetamine (IMP) and SPECT--its correction with the value of PaCO2].

To evaluate the regional cerebral blood flow measurement with N-isopropyl-p-[123I]iodoamphetamine (IMP), we performed 123I-IMP SPECT and 133Xe inhalation method on 9 patients with mild cerebrovascular diseases and so on. A tracer dose of 123I-IMP (111 MBq) was injected i.v. and the data were obtained 15 min later. Regional CBF was measured by the microsphere model and arterial blood sampling method. However, mean cerebral blood flow values was not in agreement with both methods. We supposed the reason of the disagreement was due to the difference of PaCO2 when the studies were performed. Hence, CBF measurement with 123I-IMP was performed on the other patient's population with loading of hyperventilation before the IMP injection. Comparing with the control state with normal breathing, we calculated the rate of change of mean CBF between the state with normal breathing and the state with hyperventilation that was 1.02 ml/100 g/min/mmHg PaCO2. After the correction with the rate, we observed a much significant relation between the mean CBF measured with 123I-IMP SPECT and 133Xe inhalation method. When compared CBF values with loading studies or certain therapies, the correction of CBF with the rate of change of PaCO2 is one of the very important factors to be considered. Moreover, 133Xe inhalation method without the correction of PaCO2 can not be a golden standard method for rCBF measurement.

Adult↗
PubMed1993

Protein phosphatase 1 gamma 2 is associated with nuclei of meiotic cells in rat testis.

We have shown that there are at least 4 isotypes of the catalytic subunit of type 1 protein phosphatase (PP1), PP1 alpha, PP1 gamma 1, PP1 gamma 2 and PP1 delta by rat cDNA cloning. Among these, PP1 gamma 2 mRNA was found to be abundant in rat testis. To study the roles of PP1 gamma 2 in rat spermatogenesis, we raised an antibody against a synthetic 21 mer peptide corresponding to the predicted amino acid sequence of the C-terminal region of the PP1 gamma 2. The antibody interacted with a testicular protein of 39-kDa prepared from rats after puberty (25 days after birth). However, the antibody did not interact with proteins extracted from the immature testes or from other tissues examined. Indirect immunofluorescent staining of PP1 gamma 2 of the seminiferous tubules from rats of various ages and costaining with DNA showed that the protein is located in the nuclei of late spermatocytes and of early spermatids. We suggest that PP1 gamma 2 plays some role in meiotic division during spermatogenesis.

Amino Acid Sequence↗
PubMed1993

Expression of PP2A B regulatory subunit beta isotype in rat testis.

We isolated a rat cDNA encoding part of the beta-isotype of the B regulatory subunit (BR beta) of protein phosphatase 2A (PP2A). The isolated cDNA encoded the region corresponding to amino acids positions 8(R) to 177(N) of human BR beta. The identities of the nucleotide and amino acid sequences of the rat and human BR beta s were 95.7% and 100%, respectively. The BR beta mRNA was specifically expressed in rat brain and testis, the lengths of mRNAs in these two organs being different. In the testis, the BR beta mRNA was first detected 40 days after birth, increasing gradually thereafter, and was expressed specifically in elongated spermatids, while mRNA of the alpha-isotype (BR alpha) was expressed equally in all spermatogenic cells. After meiosis, round spermatids change morphologically to elongated spermatids. BR beta may regulate the activity of the PP2A catalytic subunit in spermatids, and be involved in spermatogenic maturation, especially spermatid elongation.

Aging↗
PubMed1993

Identification of PP1 catalytic subunit isotypes PP1 gamma 1, PP1 delta and PP1 alpha in various rat tissues.

cDNA clones for 4 rat protein phosphatase 1 (PP1) catalytic subunit isotypes, PP1 alpha, PP1 gamma 1, PP1 gamma 2 and PP1 delta, were isolated (K. Sasaki et al., Jpn. J. Cancer Res. 81, 1272-1280, 1990). Antibodies were raised to determine the physiological functions of 4 isotypes. Among these isotypes, the PP1 gamma 2 protein was detected specifically in rat testis (H. Shima et al., Adv. Prot. Phosphatases, vol. 7, in press). On the other hand, PP1 gamma 1, PP1 delta and PP1 alpha were detected as 36kDa, 37kDa and 38kDa proteins in several rat organs by immunoblot analysis. All three isotypes were found in both soluble and particulate fractions. PP1 gamma 1 was predominant in the brain and PP1 delta in the brain, lung and small intestine, but the levels of both were low in the liver and muscle. It became evident that PP1 alpha was not a predominant isotype in any tissue examined.

Amino Acid Sequence↗
PubMed1993

Severe respiratory depression after epidural morphine in a patient with myotonic dystrophy.

We describe a patient with myotonic dystrophy who underwent cholecystectomy, and developed severe respiratory depression following epidural administration of morphine to provide postoperative analgesia. At preoperative assessment, he demonstrated near normal vital capacity and maximal voluntary ventilation, but the presence of chronic ventilatory failure with a resting value of PaCO2 51 mmHg. Anaesthesia was produced by a combination of epidural and light general anaesthesia without intravenous anaesthetics, narcotics or neuromuscular relaxants. Five hours after epidural administration of 2 mg morphine, the patient developed severe respiratory depression with a PaCO2 of 93 mmHg. Intravenous naloxone resulted in transient improvement in minute volume, suggesting that epidural morphine was responsible for the depression. Epidural morphine can cause unexpected respiratory depression, even at a small dose, because of the sensitivity of the respiratory centre to morphine in patients with myotonic dystrophy.

Analgesia, Epidural↗
PubMed1993

Comparison of the direct effects of sevoflurane, isoflurane and halothane on isolated canine coronary arteries.

We have demonstrated previously, using dog epicardial arteries of different sizes, that isoflurane, like adenosine, is preferentially a small coronary artery dilator, whereas halothane, like nitroglycerin, is a large artery dilator. The present study was designed to compare the direct effects of sevoflurane with those of isoflurane and halothane. Proximal large coronary arteries with an outer diameter (o.d.) of 2.5-3.2 mm and distal small arteries of 0.6-0.9 mm o.d. were isolated from dogs and then cut into vascular rings. They were precontracted with KCl (20 mM), and their relaxant responses to anaesthetics were compared relative to the maximal responses induced by papaverine. Sevoflurane, halothane and isoflurane (1-3 human MAC) induced dose-dependent relaxation of these arteries. The relaxant response to sevoflurane did not differ between large and small arteries. However, the relaxant response of the large arteries to halothane (1.5-2.3%) was greater than that of small arteries (P < 0.01) and the response of small arteries to isoflurane (3.5%) was greater than that of large arteries (P < 0.05). In large arteries, the potency of the relaxant effect at equivalent human MAC could be ranked as halothane > or = sevoflurane > isoflurane, and, in small epicardial arteries as isoflurane > sevoflurane >> halothane. We conclude that, unlike isoflurane, sevoflurane is not a preferential dilator of small coronary arteries.

Anesthetics↗
PubMed1993

Direct vascular effect of ropivacaine in femoral artery and vein of the dog.

A study was conducted to examine the direct vascular effect of ropivacaine, in comparison with the effect of bupivacaine and lidocaine. Changes in tension induced by ropivacaine (10(-5)-3 x 10(-3) mol l-1) and lidocaine (10(-5)-10(-2) mol l-1) were examined cumulatively in vascular rings of dog femoral artery and vein under basal tension, or in those which had been precontracted with phenylephrine submaximally in Krebs' bicarbonate solution at 37 degrees C aerated with 95% O2 and 5% CO2 (pH 7.4). The change in tension induced by 10(-2) mol l-1 ropivacaine was tested under basal tension in vascular rings bathed in HEPES buffer (pH 6.8). Ropivacaine induced greater constriction than bupivacaine at concentrations over 10(-3) mol l-1 in vascular rings under basal tension (P < 0.01). The maximal contraction was induced by ropivacaine at 10(-3) mol l-1, averaging 51.5 +/- 2.8% (n = 11) and 27.0 +/- 3.7% (n = 12) of the maximal contraction induced by epinephrine in the artery and vein, respectively, and the contractions induced by ropivacaine at 10(-2) mol l-1 were 16.3 +/- 2.0% (n = 11) and 5.5 +/- 1.1% (n = 9), respectively. Phenylephrine (10(-6) mol l-1)-precontracted artery was contracted significantly by ropivacaine at 3 x 10(-4) mol l-1 and 10(-3) mol l-1, and by bupivacaine at 3 x 10(-4) mol l-1, whereas the phenylephrine (10(-6) mol l-1)-precontracted vein was relaxed by these anesthetics. Lidocaine did not exert constricting effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Amides↗
PubMed1993

[The treatment of staghorn calculi].

Between May 1989 and November 1991, 19 staghorn calculi were treated by extracorporeal shock-wave lithotripsy (ESWL) with a Dornier MFL 5000 or Northgate SD-3. The 19 calculi were evaluated. Treatment was with monotherapy by ESWL in 9, combination percutaneous nephrolithotomy (PNL)-ESWL in 9, and nephrostomy in 1. Of the patients, 14 had a cross stent catheter pre-ESWL treatment to improve fragment evacuation. Radiologic follow up in 19 kidneys revealed that 57.9% were stone free. We arbitrarily separated our cases into 3 groups: struvite renal calculi, calcium carbonate calculi and others. Result of stone-free rate was 100% for stones consisting of struvite, and 14. 3% for stones consisting of calcium carbonate. In our opinion, the best indication of monotherapy by ESWL is for staghorn calculi, which consists of struvite, without marked dilation of pelvis and calyces.

Adult↗
PubMed1993

[Clinical experience with extracorporeal shock wave lithotripsy using Dornier MFL 5000-(U) for urinary stone].

Our hospital recently installed one of the newest types of extracorporeal shock wave lithotripters, a Dornier MFL 5000-(U). We conducted preliminary clinical trials with the apparatus from April to June 1991. In this report we discuss our experience with the first 40 patients (52 stones) treated in a total of 52 extracorporeal shock wave lithotripsy (ESWL) sessions. Follow up observation was conducted for three months. Except in one case, invasive anesthesia was not used. A double J-catheter was inserted in 13 cases, a ureteral catheter in 7 cases, and percutaneous nephrolithotripsy (PNL) was used after ESWL in one case. After one month of follow-up, 27 patients (67.5%) were completely free from stone fragments, while at 3 months after treatment, 34 patients (85.0%) were free from stone fragments. No serious complications were observed after ESWL. We concluded that the Dornier MFL-5000-(U) apparatus is effective for renal and ureteral stones and generates no serious complications.

Adult↗
PubMed1992

Hemodynamic changes after resection of thoracic duct for en bloc resection of esophageal cancer.

An en bloc resection of esophageal cancer is one of the most radical forms of esophagectomy, and includes the resection of the thoracic duct, but a relatively high hospital mortality rate has been reported. There is very little knowledge on the pathophysiological changes after resection of the thoracic duct. We examined 24 patients who underwent en bloc resection. Some patients developed severe tachycardia or shock postoperatively which subsided after a massive infusion of plasma. Analysis of the fluid balance revealed that much more fluid was necessary during surgery and the postoperative 24 h than in patients treated by a standard esophagectomy. Postoperative lymphangiography or CT revealed abnormal collateral lymphatics around the kidneys or in the pelvic cavity. This suggests the development of the lymphaticovenous shunts, which differed depending on the anatomy of each patient. One patient with chronic hepatitis developed uncontrollable ascites. These are important findings which can hopefully reduce the high rate of hospital death after this operation.

Aged↗
PubMed1992

Comparison of the vasodilator effects of thiopentone and pentobarbitone.

The aim of this study was to elucidate the vasodilator mechanisms of barbiturates. In helical strips of dog mesenteric artery, the effects of pretreatment with thiopentone and pentobarbitone on the contractions induced by KCl (2.0 x 10(-2) M) and norepinephrine (10(-5) M) in normal bathing fluid, and those induced by norepinephrine and caffeine (2.5 x 10(-2) M) in Ca(++)-free fluid were tested, and their effects on caffeine-induced contractions in skinned strips were also examined. Thiopentone, at concentrations over 10(-4) M, inhibited the KCl-induced contractions in normal bathing fluid and those induced by caffeine in Ca(++)-free fluid and, at concentrations over 3 x 10(-4) M, inhibited norepinephrine-induced contractions in normal and Ca(++)-free bathing fluids significantly. Pentobarbitone, at concentrations over 3 x 10(-4) M, inhibited KCl- and norepinephrine-induced contractions in normal bathing fluid significantly, whereas contractions in Ca(++)-free fluid induced by norepinephrine and caffeine were inhibited only by a high concentration (10(-3) M) of pentobarbitone. Caffeine-induced contractions of chemically skinned fibres were more susceptible to inhibition by thiopentone than by pentobarbitone. These results suggest that the vasodilator effect of thiopentone is mediated via its intracellular inhibitory effect and that, in contrast, the vasodilator effect of pentobarbitone can be attributed mainly to its Ca(++)-channel blocking action.

Animals↗