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Biomedical subjects

K Hirabayashi

Publications and source records attributed to K Hirabayashi.

At least 163 records · Page 9Linked to original sources
PubMed1986

Gastric motility is stimulated but overall blood flow is unaffected during cold restraint in the rat.

The relationship between cold restraint-induced lesion formation, gastric motility, and gastric mucosal blood flow was studied in rats. Both anesthetized and unanesthetized animals placed in cold restraint developed gastric mucosal lesions. Gastric (corpus) motility was measured using extraluminal force transducers. Animals placed in cold restraint developed persistent, high amplitude, prolonged duration contractions. Those rats in which such contractions lasted greater than 1 h developed gastric mucosal lesions, whereas those animals in which such contractions lasted less than or equal to 1 h had no lesions. Overall gastric mucosal blood flow was measured using the hydrogen gas clearance technique. There was no significant change in overall gastric mucosal blood flow measured after 1, 2, and 3 h of cold restraint. We conclude that (a) the physical effect of cold water immersion is by itself sufficient to cause cold "restraint" lesions and (b) such lesions are associated with high amplitude, prolonged duration contractions lasting greater than 1 h.

Anesthesia↗
PubMed1986

[Fundamental and clinical studies of imipenem and imipenem/cilastatin sodium in the field of obstetrics and gynecology].

Fundamental and clinical studies of imipenem (MK-0787), a new type of carbapenem antibiotic, and MK-0787 combined with cilastatin sodium (MK-0791), a renal dipeptidase inhibitor, were carried out. The results obtained were as follows: MK-0787 500 mg alone or MK-0787 500 mg with MK-0791 500 mg was administered by intravenous drip infusion over 30 minutes. Plasma levels of the drug were similar either following the administration of 500 mg of MK-0787 alone or 500 mg of MK-0787 with 500 mg of MK-0791. When MK-0787 was administered with MK-0791, MK-0787 and MK-0791 levels at 2 hours after the end of infusion in uterine arterial plasma were 6.8 micrograms/ml and 3.2 micrograms/ml, respectively, and in venous plasma were 8.4 micrograms/ml and 4.7 micrograms/ml, respectively. MK-0787 tissue levels ranged from 0.8 microgram/g to 3.8 micrograms/g at 205 minutes after the end of infusion. Based on these results, the plasma and tissue levels of MK-0787 and MK-0791 with b.i.d. dosage exceeded the MICs of the drug against clinical isolates in the field of obstetrics and gynecology such as E. faecalis, E. coli Klebsiella sp., Peptococcus sp., Peptostreptococcus sp. and B. fragilis immediately after the administration. However, it seemed that the b.i.d. dosage was insufficient to maintain the in vivo concentration of these agents high enough to inhibit the growth of the above bacteria. Eighteen patients with obstetric and gynecologic infection (12 with intrauterine infections, 2 with pelvic dead space inflammation, 2 with pelvic peritonitis, 1 with a vaginal cuff abscess and 1 with a vulvar abscess) and 1 patient with other infection (abdominal wall abscess) were evaluated, but 1 patient with pelvic peritonitis was later excluded from the efficacy evaluation because of a serious illness. MK-0787/MK-0791 was administered twice daily in a 30-minute intravenous drip infusion. Clinical results were excellent in 1 patient, good in 16 and poor in 1, for an efficacy ratio of 94.4%. No side effects were observed. Only abnormal laboratory findings observed were elevation of S-GOT and S-GPT in 1 patient which normalized 2 weeks after the treatment was discontinued. These results suggest that MK-0787/MK-0791 will be useful for the treatment of obstetric and gynecologic infections.

Adult↗
PubMed1986

[A neurochemical study of rat brain maldevelopment induced by MAM treatment at different stages of gestation].

The regional levels of several cell marker proteins in the brain and the ability of operant discrimination learning on a multiple fixed ratio (FR), fixed interval (FI) schedule were determined in rats with microencephaly induced by prenatal treatment with methylazoxymethanol (MAM), an antimitotic agent, on the 11 th to 13 th days (Group A) or on the 15 th day (Group B) of gestation. The cell marker proteins were determined with a sensitive enzyme immunoassay. Neuron-specific enolase (NSE; gamma gamma-enolase) had a significantly lowered level in the neocortex anterior in Group A. Non-neuronal enolase (NNE; alpha alpha-enolase) was significantly reduced in the superior colliculus, lateral geniculate body and optic nerve, but increased 1.5 fold in the retina in Group A. S-100b protein, a marker of astroglial cells, showed no significant change. As for the learning performance, the Group B animals showed an elevated behavioral activity and made evident discrimination between the FI and FR schedule. But Group A animals had prolonged FR components requiring responses to light on, and their spontaneous activity counts recorded by Automex showed an inhibition of behavior in light environments. These findings suggest a causative role of some developmental abnormality in the central visual system, indicated by the aberrant cell marker levels, in the disturbed learning ability of the Group A animals.

Abnormalities, Drug-Induced↗
PubMed1985

Role of blood flow in gastric and duodenal mucosal injury in the rat.

The hemorrhagic hypotension model in anesthetized rats was used to study the relationship between gastric and duodenal mucosal blood flow and susceptibility to acid-induced injury. Mucosal blood flows measured by the hydrogen gas clearance technique in the corpus, antrum, and duodenum all showed a significant linear correlation with mean blood pressure, decreasing progressively as blood pressure fell. Significant gastric mucosal lesions occurred only after mean blood pressure and hence, mucosal blood flow was reduced to below 40% of baseline values. In contrast, duodenal mucosal lesion formation was related in a linear manner to decrease in mean blood pressure or blood flow. We conclude that mild reductions in blood flow are more important in the duodenum than in the stomach in increasing susceptibility of the mucosa to acid-induced injury.

Animals↗
PubMed1985

Experimental study on postlaminectomy deterioration of cervical spondylotic myelopathy. Influences of intradural surgery and persistent spinal block.

This experiment studied the postoperative changes around the dural tube at the site of cervical laminectomy, which are influenced by intradural operative procedures and the flow of cerebrospinal fluid. Forty dogs were divided into four groups in accordance with the type of decompressive procedure done, and three types of dural surgery were added: none (laminectomy alone), dura resection, or arachnoid resection. While the scar tissue did not adhere to the spinal cord after arachnoid resection in normal dogs, adhesion of scar to spinal cord was seen to a small extent after arachnoid resection with sufficient posterior decompression in dogs whose spinal cord was compressed anteriorly by a screw through the vertebral body. In the cases with insufficient posterior decompression adherence was observed much more extensively.

Animals↗
PubMed1985

[Fundamental and clinical studies on aztreonam].

Aztreonam (AZT), a new monocyclic beta-lactam antibiotic, was studied on the transfer into intrapelvic tissues and on the clinical efficacy in the treatment of 19 cases of obstetrical and gynecological infections. The AZT levels were examined in the pelvic dead space exudate in 6 patients who received radical hysterectomy due to uterocervical cancer. The simulation curves for AZT were well performed after the decision of the pharmacokinetic parameters using the two-compartment model. Following 1-hour intravenous drip infusion of 1 g of AZT, the peak concentration of AZT in cubital venous blood was estimated 73.3 micrograms/ml at the end of infusion. The peak concentration of AZT in the pelvic dead exudate was estimated 18.6 micrograms/ml at 2.31 hours after infusion. Following intravenous 1-hour drip infusion of 1 g, the transferred level of AZT into uterine tissues was maintained at the effective concentration which means the excess level of the MIC against clinical isolates often observed in the field of obstetrics and gynecology. AZT was administered 2-4 g/day in 2 times a day by intravenous drip infusion for 60-90 minutes. The subjects were 19 patients with the following infections; pyometra (1), puerperal intrauterine infection (4), postoperative parametritis (4), pelvioperitonitis (2), purulent lymphocyst (1), acute salpingoophoritis (1), vaginal stump abscess (1), Douglas abscess (2), pelvioperitonitis + pyosalpinx (2), vulval abscess (1). Clinical efficacy was; excellent in 2 cases, good in 11 cases and poor in 6 cases. No notable side effect or abnormal laboratory finding was noted.

Adolescent↗
PubMed1985

[Fundamental and clinical studies on cefpiramide in the field of obstetrics and gynecology].

Cefpiramide (SM-1652, CPM), a new cephem antibiotic was studied for the transfer into intrapelvic tissues and clinical efficacy in the field of obstetrics and gynecology. The results were obtained as follows. Clinical results of 17 patients with obstetrical and gynecological infection were excellent in 10 cases, good in 6, and poor in 1 with the efficacy rate of 94.1%. Following a single intravenous 30 minutes-drip infusion of 1 g dose of CPM, the peak of serum level and intrapelvic tissues were obtained at 30-60 minutes after completion of the administration. No adverse reaction or abnormal laboratory findings were observed.

Adult↗
PubMed1985

[Basic and clinical studies on cefminox in the field of obstetrics and gynecology].

Fundamental and clinical studies on cefminox (CMNX, MT-141), a new cephamycin antibiotic, were carried out and the following results were obtained. When CMNX was administered at a dose of 1 g by intravenous drip infusion taking 1 hour, the serum concentrations as high as 20 micrograms/ml and 21 micrograms/ml were detected even at 4 hours after administration for the uterine artery and elbow vein, respectively. From these results, CMNX was supposed to maintain in vivo concentrations high enough to inhibit 80 to 100% of the growth of bacteria such as S. aureus, E. coli, Klebsiella, Proteus and anaerobic bacteria, B. fragilis, which are the commonest clinical isolates in the field of obstetrics and gynecology. Clinically, in 7 cases of female genital infections (4 cases of parametritis, 1 case of intrauterine infection, 1 case of pyometra and 1 case of pelveoperitonitis), CMNX was administered at a daily dosage of 2 g in 2 divided doses as intravenous drip infusions taking 90 minutes each. The clinical results were excellent in 1 case, good in 3 cases and poor in 3 cases, with an efficacy rate of 57.1%. In 6 out of these 7 cases progressive carcinoma was present as the underlying disease. No side effects nor abnormalities in laboratory findings were observed in any of the 7 cases. These results suggest that CMNX is effective in the treatment of obstetrical and gynecological infections.

Adult↗
PubMed1985

[Treatment of stage I and II ovarian cancer (interim report of intraperitoneal chemotherapeutic perfusion and postoperative prophylactic intracavitary irradiation)].

74 cases of primary ovarian cancer treated here previously were classified into three groups, no residual (corresponding to Stage Ia, Ib), cell residual (Ic-IIc) and mass residual (III, IV), and prognoses were compared. The 5 year survival rates were 83.3%, 29.4% and 12.6% respectively. In Stage I and II cases, almost all of the tumor mass would be removed by operation. Therefore the target of postoperative treatment should be the residual cancer as cell units spread widely throughout the abdominal cavity. For this purpose, IPCP has been performed on 35 cases of Stage I and II since 1977. The 3 year survival rate for this series is as good as 88.6%, and the sites of recurrence were localized in the small pelvic cavity adjacent to the Douglas pouch in 5 out of 6 relapsed cases. This fact suggests that IPCP is capable of controlling the cancer cells in the upper abdominal cavity, but still insufficient to control them in the pelvic cavity where deeper invasion is suspected. In order to improve the local control ability, utilization of the uterus as the applicator for prophylactic intracavitary irradiation came to be considered. The spread of cancer to the uterus was found in 5 out of 38 cases in Stage I and II(13.2%), but silent invasion was found in only one case. These results suggests that the utilization of the uterus as the applicator for prophylactic intracavitary irradiation would be feasible if no macroscopical cancer extention to the uterus exists and the uterus is suitable for application. Several combinations with Tandem and Ovoid have been tested and an adequate method has been proposed.

Brachytherapy↗
PubMed1985

[A summary of the experience with cisplatin in the treatment of gynecological malignancies, with special reference to advanced ovarian cancer].

This report summarizes the results on the evaluation of Cisplatin in gynecological malignancies. A total of 51 evaluable cases, comprises 29 of which were advanced or recurrent ovarian cancer and 22 of other gynecological malignancies. The main results are summarized as follow: The overall efficacy rate was 58.3% on ovarian cancer and 13.6% on other malignancies. Seen histologically, almost the same good overall efficacy rates were obtained in all types except for the mesonephroid type. When Cisplatin therapy is used in combination with surgery, the preoperative use provides a higher efficacy rate (68.2%) than the postoperative use (28.6%). Also cases with a Second Look Operation showed a much higher one year survival rate (80.0%) than those of the cases without S.L.O. (25.0%). From these results, it is deduced that Cisplatin is the most useful agent for induction chemotherapy for S.L.O. on advanced ovarian cancer. The side effects observed were milder than those of anti-cancer drugs known so far with the usual dosage, and no fetal damage was observed.

Adenocarcinoma↗
PubMed1984

[Fundamental and clinical studies on sulbactam/cefoperazone in the field of obstetrics and gynecology].

Fundamental and clinical studies on sulbactam/cefoperazone (SBT/CPZ), a combination drug of sulbactam and cefoperazone, were carried out in the field of obstetrics and gynecology. The following results were obtained: Transfer into female genital organ tissues Following 1 hour intravenous drip infusion of SBT/CPZ, favourable transfers of both of SBT and CPZ to female genital organ tissues and pelvic dead space exudate were observed. Clinical evaluation A total of 12 cases comprising 6 with intrauterine infection, 1 with pyometra, 1 with abscess of portio vaginalis, 2 with parametritis, 1 with pelvioperitonitis and 1 with purulent lymphocyst was treated with SBT/CPZ. Clinical efficacy was excellent in 6 cases, good in 5 cases and poor in 1 case, with overall efficacy rate of 92%. The bacteriological efficacy was judged as eradicated in 3, and as decreased in 2 out of 5 evaluable cases. In all of the 5 cases, isolated organisms were beta-lactamase producing organisms. No notable side effects or abnormal laboratory findings were observed except 1 case with elevations of GOT and GPT.

Adult↗
PubMed1984

[Fundamental and clinical study of ceftriaxone in the field of obstetrics and gynecology].

Ceftriaxone (Ro13-9904, CTRX), a newly developed cephalosporin antibiotic, was fundamentally evaluated through determination of the levels in the female genital organ tissues and in the pelvic dead space exudate. CTRX was also studied on its clinical efficacy in 13 cases with gyneco-obstetric infections. The transmission of CTRX into the female genital organ tissues was favorable: the peak level in each tissue was as high as 38 to 63 micrograms/g 18 to 37 minutes after administration. The level in each tissue even after about 18 hours remained around 10 micrograms/g, suggesting its better transmission into the tissues than other drugs. The transmission into the pelvic dead space exudate was also good: the level reached a peak of 100 to 120 micrograms/ml 1 to 3 hours after administration and still ranged from 74 to 76 micrograms/ml even after about 12 hours. The clinical efficacy was excellent in 5, good in 5 and poor in 3 out of 13 cases with gyneco-obstetric infections and the efficacy rate was 76.9%. Neither adverse reaction nor laboratory test abnormality was observed in any case. The above-mentioned results suggest that CTRX is a useful antibiotic for gyneco-obstetric infections.

Adult↗
PubMed1984

[Fundamental and clinical studies on ceftazidime in the field of obstetrics and gynecology].

Ceftazidime ( CAZ ) was studied for the transfer into intrapelvic tissues and for the clinical efficacy in the treatment of 20 cases of obstetrical and gynecological infections. Transfer into the tissues--Following intravenous 1 hour-drip infusion of 1 g, favourable transfer of CAZ into intrapelvic tissues was observed. The peak drug level of 50 approximately 66 micrograms/g was obtained at 5 approximately 36 minutes after completion of the administration. Clinical evaluation-- CAZ was administered at a daily dose of 2 approximately 4 g in 1 approximately 4 divided doses by intravenous drip infusion for 90 minutes. The subjects were patients with the following infections; pyometra (1), puerperal endometritis (3), parametritis (5), pelvioperitonitis (3), purulent lymphocytes (2), retroperitoneal abscess (1) and acute adnexitis (5). Clinical efficacy was; excellent in 15 cases, good in 3 cases and poor in 2 cases, with the overall efficacy rate of 90.0%. No notable side effects or abnormal laboratory findings were observed except for eruption in 1 case.

Adult↗
PubMed1983

Prostaglandin cytoprotection. Prostaglandin does not protect against aspirin- or alcohol-induced red blood cell hemolysis.

The hypothesis that prostaglandin cytoprotection involves cell membrane stabilization was tested in vitro using rat erythrocytes. Low concentrations of sodium acetylsalicylate, 0.02, 0.2, 2.0, and 20 mM, inhibited hypotonic hemolysis of red blood cell suspensions. While 35, 140, and 280 mM sodium acetylsalicylate had no hemolytic effect, 560 mM caused marked hemolysis. The prostaglandin E2 analog, 16,16-dimethyl prostaglandin E2, 0.4 X 10(-3), 10(-4), and 10(-5) M concentrations, did not alter this hemolysis. Fourteen percent ethanol caused red cell hemolysis, and this was unaffected by the prostaglandin. The findings do not support the hypothesis.

Animals↗