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Biomedical subjects

M Oki

Publications and source records attributed to M Oki.

At least 55 records · Page 3Linked to original sources

[A case of signet ring cell carcinoma of the urachus].

A 71-year-old female was seen initially with the complaint of gross hematuria. Cystoscopic examination revealed non-papillary tumor at the dome of the bladder and a transurethral biopsy showed signet ring cell carcinoma. En bloc segmental resection was performed, and the patient has been well without any evidence of progression. We report a case, which we believe to be the 6th in Japan, of signet ring cell carcinoma of the urachus.

Adenocarcinoma, Mucinous↗

[Clinical application of extracorporeal shock wave lithotripter (SD-3) to upper urinary tract stones].

The extracorporeal shock wave lithotripter (SD-3) was used on 30 patients with upper urinary tract calculi from December, 1988 to March, 1989. At one month after the treatment, 11 patients (36.7%) were free from stones and 9 (30.0%) had stone fragments than 5 mm in diameter, making an effective rate of treatment of 66.7%. Gross hematuria, skin ecchymosis, pain and fever were observed as side effects, but none of them were serious. We concluded that extracorporeal shock wave lithotripsy using SD-3 for upper urinary tract stones is an effective treatment without any serious side effects.

Adult↗

[Treatment of superficial bladder tumor].

In period of April, 1982 to March, 1987 for 5 years, fifty-four patients with superficial bladder tumors were treated at the Department of Urology, Nippon Medical School. There were 42 males and 12 females with age ranged from 28 to 85 years old. All patient underwent TUR-Bt (trans urethral resection-bladder tumor) as an initial treatment. The rather long term follow-up study after initial treatment was 47 months in average. Recurrence rate at 2 years after TUR-Bt was 30%. The risk factors of recurrence were analysed in connection with sex, age, tumor number, histological grade and stage, and infiltration pattern. In conclusion, significantly higher recurrence rate were observed in G2 than G1 and G3, and in pT1b rather than pTa and pT1a. Other factors were not distinctly correlated with incidence of recurrence.

Adult↗

An in vitro study of the projections of enteric vasoactive intestinal polypeptide-immunoreactive neurons in the human colon.

The anatomical basis of the peptidergic neural control of the human colon is largely unknown. In this study, in vitro retrograde tracing methods have been used on fresh human colon to determine the projection pathways of the enteric nerves and, in particular, those containing vasoactive intestinal polypeptide, one of the most abundant and potent of the gut neuropeptides. Two components of the submucous plexus were identified, the inner one projecting to the lamina propria, and the outer to the circular muscle. The lengths of projections within the submucous plexus were up to 5-14 mm in all directions. Myenteric ganglion cells projected to both longitudinal and circular muscles, for distances of up to only 5 mm. The subpopulation of nerves containing vasoactive intestinal polypeptide arose mainly from the submucous plexus and projected up to 6.5 mm anally, 5 mm orally, and 14 mm within the submucous layer to the mucosa or circular muscle. These findings provide entirely new data on the neuroanatomy of the human colon and may help in the understanding of the neural control of colonic secretion and motility.

Adult↗

Purification of polymeric phospholipase Cs from human platelets.

Two types of cytosolic phospholipase C specific for phosphoinositides were purified from human platelets. The molecular masses of the purified enzymes were 440 and 290 kDa. These enzymes were concluded to be respectively a trimer and a dimer of homologous 146 kDa polypeptides. The 146 kDa polypeptide may be an immunologically novel isozyme among the 140-150 kDa PLC isozymes. Both enzymes hydrolyzed phosphatidylinositol and phosphatidylinositol 4,5-bisphosphate in a Ca2(+)-dependent manner.

Blood Platelets↗

Pharmacological activities of synthetic human cholecystokinin-33 of which tyrosine was sulfated by arylsulfotransferase.

The pharmacological activities of synthetic human CCK-33, in which a tyrosine molecule was sulfated by arylsulfotransferase, were investigated in the rat and the guinea-pig. The activities were compared with those of non-sulfated CCK-33 (CCK-33NS), CCK-8 and CCK-4. CCK-33 was about 100 fold more potent than non-sulfated CCK-33(CCK-33NS) but was about 20 fold less potent than CCK-8 in the contraction of the isolated gallbladder of the guinea-pig. In rat pancreatic secretion, intravenous CCK-33 and CCK-8 showed almost the same activity. The potency of each was about 1000 fold more than the individual potency of CCK-33NS, non-sulfated CCK-8 (CCK-8NS) and CCK4. There were no significant differences in gastric acid stimulatory activities among CCK-33, CCK-8, CCK-4, but the activities of CCK-33NS and CCK-8NS were less than those of CCK-33 and CCK-8, respectively. CCK-33 and CCK-8 produced a reduction in the intake of powder chow in doses of 10(-8) and 3 x 10(-8) mol/kg i.p., but CCK-33NS, CCK-8NS and CCK-4 did not. In conclusion, the activities of synthetic human CCK-33 are almost the same as those of CCK-8 on exocrine pancreatic secretion, gastric acid secretion and food intake, but less than CCK-8 on isolated gallbladder contraction.

Animals↗

Pharmacological activity of angiotensin-II modified by tyrosine sulfation.

An angiotensin-II analogue with a sulfated tyrosine residue was prepared by arylsulfotransferase treatment of synthetic human angiotensin-II. Its biological activities were studied in isolated smooth muscles, and its effect on blood pressure was determined. The sulfated angiotensin-II (AII-S) was about 15-30 fold less potent than angiotensin-II (AII) for ileum contraction and gallbladder contraction. The hypertensive potency of AII-S was about 30-fold less than that of AII.

Angiotensin II↗

Distribution and function of enteric GAL-IR nerves in dogs: comparison with VIP.

The distribution of nerves containing galanin-immunoreactive (GAL-IR) material was compared to the distribution of neurons containing vasoactive intestinal polypeptide (VIP) immunoreactivity in the canine gastrointestinal tract. The actions of intra-arterially administered galanin and VIP on motility in the gastric antrum and corpus and the intestines were also studied. All sphincter muscles contained galanin- and VIP-immunoreactive nerve profiles. VIP-immunoreactive nerve profiles were present in all layers of the stomach, small intestine, and colon. GAL-IR nerve somata were common in the submucous plexus of ileum and colon and in the myenteric plexus of the terminal antrum, as were nerve processes in various layers. In the small intestine, galanin inhibited contractile responses to field stimulation of intrinsic nerves and also reduced the contractions after nerve blockade with tetrodotoxin (TTX). VIP often enhanced field-stimulated contractions at low doses but inhibited these and the contractions after TTX at higher doses. In the stomach and colon, both peptides inhibited responses to field stimulation; whether these effects were due to actions on smooth muscle was not tested. The distribution and actions of galanin in gut are consistent with the hypothesis that it acts at smooth muscle sites and possibly at prejunctional sites.

Animals↗

Frequency dependence of the suppressive effects of vibration on atherosclerosis in the rabbit.

Whole-body vibration suppresses the development of atherosclerosis in the rabbit (Oki and Matoba, 1987). The present study was designed to clarify whether the effect of vibration on atherosclerosis depends on the frequency of vibration. Longitudinal vibrations at a frequency of 30 or 60 Hz was applied to 12 New Zealand white rabbits for 12 weeks. The gradual decrease in body weight and blood hematocrit in the vibration groups with time were parallel to the changes in the controls. The rate of increase in serum lipid concentrations induced by a cholesterol-rich diet was significantly suppressed in the vibration groups, as compared to the controls. This may be due to the vibration and not the diet. The aortic wall was thinner at 60 Hz than at 30 Hz, whereas the ratios of trace metals (Ca/Mg and Zn/Cu) in the aortic tissues were smaller at 30 Hz. The area of plaque formation in the intima was smaller at 60 Hz than at 30 Hz (p less than 0.05). Thus, the suppressive effect of vibration on the development of atherosclerosis in the aorta may be greater at a frequency of 60 Hz than at 30 Hz. Vibration may play an important role in lipid metabolism.

Animals↗

[243 cases of percutaneous nephrolithotomy--result of 5 years].

Between May, 1982 and April, 1987, upper urolithiasis of 247 kidneys of 243 patients, 174 male and 69 female, were treated by percutaneous nephrolithotomy (PNL). The main stone was successfully removed from 236 kidneys (about 95.5%). Seven cases of ureteral stone could not be removed by PNL, and were treated by traditional ureterolithotomy. In 3 cases of pelvic stone, the stone descended to the ureter during the PNL procedure, and was also removed by ureterolithotomy. In one case of pelvic stone, complete obstruction of uretero-pelvic junction after PNL occurred, and pyeloplasty was needed. One pelvic stone patient who had basical hypertension and arrhythmia died soon after PNL, because of acute myocardial infarction. Blood transfusion was needed in 31 cases (12.8%). The residual stones over 5 mm were noticed in 48 cases (20.3%). The most important point to succeed in PNL is to make a nephrostomy through the most suitable calyx to the stone. The easiest way to identify the location and connection of the aimed calyx with the stone in three dimensional position, is to take X-ray films in intravenous pyelograms not only from postero-anterior but also oblique positions. Additional transureteral lithotripsy (TUL) for the fragment descending to the ureter after PNL produces a much better result.

Adolescent↗

Neural control of canine colon motor function: studies in vivo.

The responses of the circular muscle of canine colon to stimulation of intrinsic nerves and to the probable mediators of these nerves were studied in vivo. In vivo studies were carried out using close intra-arterial injections and local field stimulation of proximal, mid-, and distal colon while recording circumferential contractions. Our results suggest that acetylcholine is the major excitatory mediator, but another excitatory mediator could be released by high frequency field stimulation after atropine. Norepinephrine had mixed inhibitory and excitatory effects, but no evidence was obtained that it was released by field stimulation. Substance P had mainly excitatory effects partly by a mechanism involving nerves and partly by a direct effect on muscle; it in addition to norepinephrine deserves further evaluation as the mediator of noncholinergic excitation to high frequency field stimulation. There is no explanation of the inhibition it produced after initial excitation during field stimulation. Vasoactive intestinal peptide had inhibitory effects but these were incomplete and inconsistent. This may be related to our inability to demonstrate relaxation or inhibition to field stimulation after atropine. Further evaluation of the possible role of vasoactive intestinal peptide and other agents as nonadrenergic, noncholinergic inhibitory mediators is required.

Animals↗

Neural control of canine colon motor function: studies in vitro.

The responses of strips of the canine colon to stimulation of intrinsic nerves and to the probable mediators of these nerves were studied in vitro. Studies were carried out using longitudinal and circular muscle strips from proximal and distal colon with field stimulation and addition of agents to the bath. Overall, these and other studies in vivo suggested that acetylcholine was an ubiquitous mediator of neural excitation. Norepinephrine had mixed inhibitory and excitatory effects, the latter only in circular muscle. Inhibitory effects of norepinephrine seemed to be both pre- and post-synaptic but no evidence that it was released by field stimulation was obtained. Substance P had excitatory effects chiefly by release of acetylcholine. It, in addition to norepinephrine, at least in circular muscle, deserves evaluation as the mediator of noncholinergic excitation to high frequency field stimulation. Although vasoactive intestinal peptide sometimes had inhibitory effects, these were incomplete and inconsistent. However, further evaluation of its possible role as a nonadrenergic, noncholinergic inhibitory mediator is required to determine if it is involved as one component in the response. Few qualitative differences existed between responses of various regions of the colon to potential neuromediators, although there were some consistent differences between responses of longitudinal and circular muscle. Some differences existed in responses obtained earlier in vivo and in vitro. In particular, inhibitory effects following excitation by substance P on field stimulation were found only in vivo. Nonadrenergic, noncholinergic inhibitory responses to field stimulation were consistently present only in vitro. These differences have not been explained.

Animals↗

[The influence of percutaneous nephrolithotomy on renal function evaluated by 99m-Tc-DTPA renoscintigram].

The influence of percutaneous nephrolithotomy (PNL) on renal function was evaluated by 99m-Tc-DTPA renoscintigraphy. The renoscintigram was recorded and regions of interest of both kidneys (R) and background (BKG) were settled. Renal uptake ratio was calculated by the following formula. Renal uptake ratio = (formula; see text). The renal uptake ratio of 50 patients were compared before and up to 6 months after PNL. Most cases showed an increase or no change in post-PNL renal uptake ratio in operated kidney. Five cases (10%) showed decreased renal uptake ratio of post-PNL. No risk factors for the renal damage caused by PNL such as age, sex, stone size, number of nephrostomy and course of PNL were detected when compared with increased or no change groups. In cases of complete staghorn calculi in the decreased renal uptake ratio group, compensatory hypertrophy of contralateral kidney PNL course might occur, and the function of the operated kidney might not have recovered. More during cases and longer follow-up is necessary for the recovery of renal function.

Female↗

Studies on the stability of muroctasin and degradation products built under extreme conditions.

Decomposition of N2-[(N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine (MDP-Lys(L18), muroctasin) under extreme conditions was investigated. MDP-Lys(L18) in an aqueous solution was heated under reflux for 4 h to give the decomposition products D-1, D-2, D-3 and D-4. Reaction of MDP-Lys(L18) with 0.1N NaOH at room temperature for 5 h gave D-1, and that with 1 N HCl under reflux for 1 h afforded D-4. MDP-Lys(L18) was found to be stable to light and heat. MDP-Lys(L18) in a powder form was stored at room temperature or at 25 degrees C and 75% relative humidity for 3 days to 18 months. Quantitative analysis, thin-layer chromatography, and tests for appearance and color change, etc., were performed in the stored samples. MDP-Lys(L18) was found to be stable, but hygroscopic.

Acetylmuramyl-Alanyl-Isoglutamine↗

Distribution of nerves containing vasoactive intestinal polypeptide-like immunoreactivity in rats with congenital aganglionosis of the colon.

The distribution of nerves containing vasoactive intestinal polypeptide-like immunoreactivity was examined immunohistochemically in whole-mount specimens of the colons of mutant rats, which completely lacked intramural nerve cells in the colon, and of their normal littermates. In the aganglionic colon, greatly diminished numbers of vasoactive intestinal polypeptide-like immunoreactive nerve fibers were found in the circular muscle layer, lamina propria of the mucosa, and in the submucosa. In the intermuscular space of the aganglionic colon, unlike the pattern of the normal Auerbach's plexus, vasoactive intestinal polypeptide-like immunoreactive nerve fibers were arranged in an irregular, coarse network. These findings suggest the existence of extrinsic nerves containing vasoactive intestinal polypeptide in the aganglionic colon of the hereditary aganglionic rat.

Animals↗

[A case of retroperitoneal fibrosis].

We report a case of retroperitoneal fibrosis. A 75-year-old man complained of edema of bilateral lower limbs and lumbago. Blood urea nitrogen and serum creatinine were increased. Renal function was improved after he had bilateral percutaneous nephrostomies. Antegrade pyelography showed bilateral hydronephrosis, left ureteral obstruction and medial deviation with narrowing of the right ureter. CT revealed a soft tissue density surrounding the aorta, inferior vena cava and bilateral ureters in the retroperitoneal space. Inferior venocavagraphy displayed stenosis. Bilateral ureterolysis combined with omental sleeve plasty was performed. Post-operatively, the clinical course has continued to be good.

Aged↗