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Biomedical subjects

S Kawamura

Publications and source records attributed to S Kawamura.

At least 325 records · Page 18Linked to original sources
PubMed1990

The effect of high-energy underwater shock waves on implanted urinary bladder cancer in rabbits.

We have examined the effects of high-energy shock waves (HESW) on implanted urinary bladder cancer in rabbits. The bladder cancer was exposed to 2000 to 6000 shots of focused HESW under ultrasound guidance. Although only focal necrosis of the tumor was seen in the one-day HESW exposure (2000 shots), wider and deeper necrosis was observed in the tumors following serial HESW (4000 or 6000 shots; 2 or 3 days). These results indicate that serial HESW exposure has destructive effects on implanted bladder cancer in rabbits.

Animals↗
PubMed1990

Measurement of endotoxic activity in feces of normal horses.

Two chromogenic Limulus amebocyte lysate systems were evaluated for the measurement of endotoxic activity in feces of normal horses. Fecal extracts had neither non-specific nor inhibitory effect on the test reaction, and the two systems with different specificity showed equivalent results. Endotoxic activities in feces of healthy horses averaged 5.7 +/- 2.8 microns/g wet weight. Correlation between the endotoxin levels and the fecal microbial flora could not be determined.

Animals↗
PubMed1990

[Two cases of psittacosis accompanied with rhabdomyolysis].

We experienced two cases of atypical pneumonia accompanied with rhabdomyolysis and diagnosed them as psittacosis based on the results of investigation of paired serum samples. Rhabdomyolysis may be associated with some kinds of viral or bacterial infections, but no report was found in the case of psittacosis as far as we searched and such a description was not found in textbooks. Heretofore, the elevation of GOT and LDH as the laboratory findings in psittacosis was considered as the reflection of liver injury, but that might be brought about by rhabdomyolysis. Although the mechanism(s) of the occurrence of rhabdomyolysis in psittacosis is unknown, when the elevation of muscular origin-enzymes including CPK is recognized in cases of atypical pneumonia, it may be the clue of diagnosis of psittacosis.

Adult↗
PubMed1990

Isolation and purification of a low molecular weight protein from bovine urine.

A low molecular weight protein was separated from urine samples obtained from a heifer with spontaneous renal disease and from cows with CaNa2EDTA-induced renal dysfunction. The molecular weight and electrophoretic mobility of the separated protein were examined. The low molecular weight protein collected by gel filtration chromatography was further separated into two fractions by ion exchange chromatography using DEAE-cellulose. One of the two fractions, the lowest molecular weight protein showed a single band in SDS-PAGE, and its molecular weight was approximately 12,000. An antiserum against this protein formed a single precipitin line with the urine from cows with experimentally induced renal dysfunction and a heifer with spontaneous renal disease by the double immunodiffusion technique. However, the antiserum did not form any precipitin line with the concentrated urine of healthy cow and human beta 2-microglobulin. In cellulose acetate membrane electrophoresis, this protein migrated in the same position as that of serum gamma-globulin from healthy cow.

Animals↗
PubMed1990

Comparison of the intestinal bacteria in specific pathogen free mice from different breeders.

Specific pathogen free BALB/c mice from 3 commercial laboratory animal breeders in Japan were compared on the composition of caecal flora revealed by selective and nonselective cultivation as well as direct microscopical observation on smears, and relative caecal weight. Large differences were detected in viable counts of total bacteria and almost all bacterial groups, while direct microscopical counts which consisted mainly of fusiform bacteria were almost equal, resulting in diverse recovery rates among 3 breeders. Eubacterium and spiral shaped organisms were not detected from all breeders. There also existed variations within breeders, especially those in the number of Enterobacteriaceae. Relative caecal weight also differed among breeders, suggesting the participation of variety of caecal bacteria in determining this parameter. As these variations in bacteriological status of animals can influence experimental results, standardization of intestinal microbial flora is required.

Animals↗
PubMed1990

Ureteral action potential and histological changes in the upper urinary tract receiving the formalin.

The present study investigates the ureteral action potential and histological changes of pelvi-ureteral system after injection of the formalin into the obstracted ureters or the renal pelvis. In the first experiment, formalin was injected into the obstructed ureters of 18 dogs for 30 minutes. In the second, formalin was injected into the obstracted renal pelvis of 13 dogs for 30 minutes using ureteral balloon catheters, and then renal pelvis were released from obstraction and catheters were removed. In these experiments, ureteral electromyogram were recorded and histological changes of pelvi-ureteral system were also observed microscopically. Results 1. After injection of formalin into the ureters, ureteral action potential disappeared and had not restored. Histologically, damage was observed in the ureteral smooth muscle as well as in the mucosa. 2. After injection of formalin into the renal pelvis, ureteral action potential disappeared in 46% of the ureters. In 54% of the ureters, action potential had not disappeared, however discharge interval became irregular. Histological changes of the renal pelvis was not related to the presence or absence of ureteral action potential. The results of the present study show that ureteral smooth muscle play part in the conduction of the ureteral excitation, and have an irregular autonomic discharge.

Action Potentials↗
PubMed1990

[Studies on function of the upper urinary tract. XXIX. Canine ureteral electromyogram isolated from "so-called Pacemaker"].

Many workers have reported that ureteral peristaltic movement is controlled by the "so-called Pacemaker". But, in our recent studies, it was revealed that the existence of pacemaker is not always necessary for the peristaltic movement. In this study, we made isolated and non-isolated prototype models, using 18 mongrel dogs, to explore the influential factors on ureteral peristaltic discharge. Bilateral kidney and ureter were exposed transperitoneally. Unilateral upper urinary tract was prepared to preserve the pacemaker without renal blood supply, and contralateral one was prepared not to preserve the pacemaker by cutting at the proximal portion of the ureter. Vesico-ureteral reflux (VUR) was caused on these two models. A luminal pressure and ureteral electromyogram was recorded. In the result, there is spontaneous peristaltic discharges of the ureter which had the tendency to increase peristaltic frequency according to the increase of the luminal pressure. It was suggested that adequate expanding stimulation is the factor of peristaltic discharge to increase, and the peristaltic discharge under this condition propagates from upper to lower portion of the ureter.

Action Potentials↗
PubMed1990

[A case of adenocarcinoma in the renal pelvis and urinary bladder in a patient with chronic renal failure].

The patient was a 61-year-old male who had undergone right nephrectomy for nephrolithiasis 35 years before. He had been on hemodialysis for 6 years for chronic renal failure caused by left renal staghorn calculus and hydronephrosis. He was admitted to our hospital because of macroscopic hematuria and sense of residual urine which had persisted for 3 months. Cystoscopic examination showed an extensive papillary tumor in the urinary bladder, which histologically was an adenocarcinoma. Giant left hydronephrosis associated with staghorn calculus noted by KUB and CT scan. Total cystectomy, intraoperative radiotherapy, and left nephrostomy were performed under the diagnosis of adenocarcinoma of the urinary bladder and left hydronephrosis. The bladder tumor was found to be a mucinous adenocarcinoma. The patient died from a cerebral hemorrhage on the 17th postoperative day. At autopsy, tumors were found in the pelvis of the left kidney and the middle and lower regions of the ureter, which were adenocarcinoma like the bladder tumor. Adenocarcinoma occurring simultaneously in the renal pelvis and bladder has not been previously reported to our knowledge, in Japan or elsewhere.

Adenocarcinoma, Mucinous↗
PubMed1990

[A case report of Cushing syndrome due to three distinct adenomas of the right adrenal].

A case is presented of a 40 y.o. female with Cushing's syndrome. Her plasma glucocorticoid values were elevated (11-deoxy-cortisol: 3.46 ng/ml, cortisol: 25.6 micrograms/dl and cortisone: 35.7 ng/ml) with loss of diurnal variation. Urine 17-OHCS value failed to b suppressed by high dose dexamethasone and was unchanged after metyrapone administration. Her plasma mineral corticoids and androgens were within normal limits. There were 3 separate tumors in the right adrenal on CT and the left adrenal had no uptake on 131I-adosterol scintigram. We, therefore, diagnosed her illness as Cushing's syndrome due to unilateral multiple adenomas. Gross and histological examination of the right adrenal revealed one compact cell dominant adenoma and two clear cell dominant adenomas. This is the 4th case of Cushing syndrome due to unilateral multiple adrenal adenomas in Japan.

Adenoma↗
PubMed1990

An improved closed cranial window technique for investigation of blood-brain barrier function and cerebral vasomotor control in the rat.

A modification of the closed cranial window technique for small laboratory animals is presented. The method facilitates investigation of blood-brain barrier permeability in association with studies of the cerebrovascular response under normal and pathological conditions. Following trephination and preparation of the pia-arachnoid surface, the skull defect is closed again by sealing a cover glass onto a wall of dental cement surrounding the cranial window. The intracranial pressure can then be studied and experimentally manipulated. Care is taken to maintain normal blood-brain barrier function to a small barrier indicator (Na(+)-fluorescein, MW: 376). This is accomplished by opening the skull and dura mater under a column of paraffin oil to avoid exposure of brain tissue to atmospheric pressure. Reactivity of the cerebral surface vessels was assessed during hypercapnia at an arterial PaCO2 of 50.8 +/- 1.1 mm Hg. It was found that small arterioles of 20-50 microns phi had a significantly larger CO2-response than large arterioles of 50-100 microns phi. Pial venules did not respond at all. Superfusion of the cranial window preparation at a rate of 5 ml/h with buffered artificial CSF was tolerated for hours. No alterations of arteriolar or venular diameters nor opening of the blood-brain barrier to Na(+)-fluorescein was observed. These technical modifications enable us to employ a closed cranial window model in small laboratory animals for studies of cerebral microcirculation and blood-brain barrier function under normal as well as under pathological conditions related to brain damage.

Animals↗
PubMed1990

[Preclinical evaluation of several cisplatinum analogs against human esophageal carcinoma by subrenal capsule assay].

The antitumor activities of CDDP analogs (CBD-CA, NK-121, 254-S) were evaluated preclinically by subrenal capsule assay (SRCA) with cyclophosphamide pretreatment. In the fundamental study, the antitumor activities against serially transplanted human esophageal cancer xenograft (IMEs-1) were compared with subcutaneous transplantation assay in nude mice and SRCA. The antitumor activities in SRCA were similar to those of in nude mice assay system (CBDCA greater than CDDP greater than 254-S greater than NK-121). Thus SRCA was considered to be useful for the evaluation of the activities of these agents. The activities were also tested against 10 human esophageal tumors obtained clinically. The sensitivity rate of these agents were 50% in CDDP, 30% in CBDCA, 30% in NK-121, and 30% in 254-S, respectively. These analogs seemed to be less effective than CDDP. However, in two cases, analogs were active though CDDP were inactive. The results suggest that these analogs are useful for the cases in which CDDP can not be given due to the toxicities and also for outpatient use.

Animals↗
PubMed1989

Growth characteristics of Tyzzer's organism in cultured mouse hepatocytes.

The growth characteristics of Tyzzer's organisms in cultured mouse hepatocytes were examined by direct bacterial counting and plaque assay. The viability of propagated bacteria and time required for the maximum titers depended on incubation time and inoculum dose, respectively. Both infectious titers and bacterial counts at optimum harvests were much higher than those obtained from infected mouse livers. Immunofluorescence revealed, after a lag phase of about 2 h, a linear multiplication during a 6 h period.

Animals↗
PubMed1989

Intracavernous injection of prostaglandin E1 for the treatment of erectile impotence.

We administered intracavernous injections of 20 micrograms. prostaglandin E1 to 135 patients with impotence, and evaluated the effects and side effects. Among 135 patients who underwent intracavernous injection of prostaglandin E1 complete erection was observed in 83 (62 per cent), while incomplete erection was noted in 33 (24 per cent). In both groups the erection was sufficient for sexual intercourse. Tumescence without rigidity was noted in 12 patients and no response was obtained in 7. Poor response was seen frequently in patients with disorders of the vascular system and/or damage to the cavernous body of the penis. Priapism after the injection was not observed. Moreover, we never observed any other severe side effects. Intracavernous injection of prostaglandin E1 could be applicable to the therapy of impotence, especially that due to neurogenic disturbance. Since prostaglandin E1 acts quickly and loses its validity rapidly it is considered to be a more suitable agent than other vasoactive drugs.

Adult↗
PubMed1989

Factors affecting infectivity of Tyzzer's organism in cultured mouse hepatocytes.

Factors affecting the infectivity of Tyzzer's organism, an obligate intracellular bacterium, were examined in cultured mouse hepatocytes. The organisms were subjected to physical and chemical impairments and the infectivity was estimated by immunofluorescence that discriminated adhesion and entry of the organisms to host cells and by the plaque assay. Pretreatment of the organisms with either mild heat or formalin abolished adhesion. UV irradiation completely removed the plaque forming ability, while adhering and entering capacity were more resistant in this order. Entry of the organism into host cells was suppressed in the presence of erythromycin, gentamicin or oxytetracycline, while it was relatively little susceptible to ampicillin, kanamycin or rifampicin. Plaquing efficiencies were increased by centrifugation during the infection. These results suggest that not only a structural but also a functional integrity of the organisms was requisite for establishment of the infection at the initial stage.

Animals↗
PubMed1989

Regulation of cGMP levels by guanylate cyclase in truncated frog rod outer segments.

Cyclic GMP is the second messenger in phototransduction and regulates the photoreceptor current. In the present work, we tried to understand the regulation mechanism of cytoplasmic cGMP levels in frog photoreceptors by measuring the photoreceptor current using a truncated rod outer segment (tROS) preparation. Since exogenously applied substance diffuses into tROS from the truncated end, we could examine the biochemical reactions relating to the cGMP metabolism by manipulating the cytoplasmic chemical condition. In tROS, exogenously applied GTP produced a dark current whose amplitude was half-maximal at approximately 0.4 mM GTP. The conductance for this current was suppressed by light in a fashion similar to when it is activated by cGMP. In addition, no current was produced in the absence of Mg2+, which is known to be necessary for the guanylate cyclase activity. These results indicate that guanylate cyclase was present in tROS and synthesized cGMP from exogenously applied GTP. The enzyme activity was distributed throughout the rod outer segment. The amount of synthesized cGMP increased as the cytoplasmic Ca2+ concentration of tROS decreased, which indicated the activation of guanylate cyclase at low Ca2+ concentrations. Half-maximal effect of Ca2+ was observed at approximately 100 nM. tROS contained the proteins involved in the phototransduction mechanism and therefore, we could examine the regulation of the light response waveform by Ca2+. At low Ca2+ concentrations, the time course of the light response was speeded up probably because cGMP recovery was facilitated by activation of the cyclase. Then, if the cytoplasmic Ca2+ concentration of a photoreceptor decreases during light stimulation, the Ca2+ decrease may explain the acceleration of the light response during light adaptation. In tROS, however, we did observe an acceleration during repetitive light flashes when the cytoplasmic Ca2+ concentration increased during the stimulation. This result suggests the presence of an additional light-dependent mechanism that is responsible for the acceleration of the light response during light adaptation.

Animals↗