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Biomedical subjects

M Shintani

Publications and source records attributed to M Shintani.

At least 73 records · Page 4Linked to original sources

Lesioning of the rat basal forebrain leads to memory impairments in passive and active avoidance tasks.

Effects of the bilateral electrolytic lesioning of the basal forebrain (BF), including the ventral globus pallidus, on passive or active avoidance tasks, were studied in male Wistar rats. A severe deficit in acquisition of passive avoidance response was produced by the lesioning in the posterior level of BF. The retention of the passive avoidance response was markedly disrupted with post-training lesioning. Time-dependent but only slight recovery from the memory impairments was observed in the passive avoidance task given 4, 8 or 16 weeks after BF lesions. The acquisition of active avoidance response using a two-way shuttle box was also disturbed by BF lesioning. Retention of active avoidance response was clearly impaired by post-training lesions of the BF. The BF lesioned rats gradually acquired the passive avoidance performance when trained repeatedly at 24- or 48-h intervals, by giving a foot shock in case of avoidance failure. Extinction of the acquired passive avoidance response rapidly occurred in the BF lesioned rats. Furthermore, neurotoxic lesions of BF with kainic acid produced a significant impairment in acquisition of passive avoidance response. These results suggest that bilateral BF lesions impair the acquisition and retention of passive or active avoidance response, and that these impaired rats may be useful as an experimental model for Alzheimer's disease and senile dementia.

Animals↗

Comparison of the efficacy of egg yolk extract and horse serum for growth of Mycoplasma pneumoniae.

The usefulness of chicken egg yolk extract as a substitute for horse serum in culture media for Mycoplasma pneumoniae was investigated. As a growth-supporting factor in the growth medium for M. pneumoniae and some other mycoplasmal species, the primary isolation medium for M. pneumoniae, and the metabolism-inhibition test medium for diagnosis of M. pneumoniae infection, egg yolk extract may be an excellent substitute for horse serum. The particular superiority of egg yolk extract to horse serum is that egg yolk extract, unlike horse serum, did not show any inhibitory effect on the growth of M. pneumoniae.

Blood↗

[Effect of TRH and its analog DN-1417 on anoxia-induced amnesia in mice].

The effect of neuropeptides and their analogs on anoxia-induced amnesia was examined using one-trial passive avoidance task in mice. Anoxia, produced by the exposure to CO2 immediately after the acquisition of avoidance response, induced amnesia which is shown by a short latency to enter from the safety compartment into the shocked compartment in the retention test conducted 24 hr later. In these anoxia-treated animals, thyrotropin-releasing hormone (TRH: 10-20 mg/kg), its analog DN-1417 (10-20 mg/kg) and ACTH 4-10 (66 micrograms/body), which were given sc 15-60 min before the retention test, markedly prolonged the latency in a dose-dependent manner, indicating a reversal of the amnesia. Arginine- and lysine-vasopressin also reversed the amnesia at a dose of 100 micrograms/body. These results suggest that TRH and DN-1417, known to reverse the amnesia produced by the protein synthesis inhibitor cycloheximide, have ameliorating effects on the retrieval process of memory.

Adrenocorticotropic Hormone↗

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

Cefpiramide (CPM, SM-1652), a new cephem antibiotic, was fundamentally and clinically studied. The following results were obtained. Serum and internal genital tissue levels of CPM were measured following intravenous drip infusion of 1 g. High serum levels of 30 micrograms/ml and tissue levels of more than 4 micrograms/g were at least maintained for 8 hours. Favourable transfer of CPM into the pelvic dead space exudate was observed. The exudate level was 7.25 micrograms/ml on average even at 8 hours after intravenous drip infusion. A total of 6 cases comprising 4 with Bartholin's cyst, 1 with pelvic peritonitis and 1 with lymphocyst was treated with CPM at a dose of 0.5-2 g twice daily by intravenous injection or intravenous drip infusion. The clinical response was excellent in 1 case and good in 5 cases. Side effects and abnormal laboratory findings due to the drug were not noted.

Adult↗

Inhibition of growth of mammalian cell cultures by extracts of arginine-utilizing mycoplasmas.

Mechanisms of the inhibition of growth of mammalian cell cultures caused by mycoplasmal infection were investigated by using cell-free extracts of 14 species of mycoplasmas. In four mammalian cell lines tested, the growth of two cell lines, FM3A and MDCK, was inhibited by the extracts of arginine-utilizing mycoplasmas, whereas that of the other two cell lines, Vero and LLC-MK2, was not inhibited by extracts of either arginine- or glucose-utilizing mycoplasmas. These results suggest that there are two types of cell cultures, one susceptible and the other insusceptible to arginine-utilizing mycoplasmas. In a series of experiments using FM3A cells, it was found that the growth inhibition caused by the extracts of arginine-utilizing mycoplasmas was due to removal of arginine from the medium by the action of arginine deiminase present in the extracts and that none of the metabolic products of arginine had any effect on the growth. A highly positive correlation (r = 0.96, P less than 0.01) was observed between the activity of arginine deiminase and the growth-inhibiting activity of extracts of arginine-utilizing mycoplasmas.

Animals↗

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

Sulbactam/cefoperazone (SBT/CPZ), a new developed antibiotic, was clinically studied. The following results were obtained. Total of 5 cases comprising 1 with endometritis, 3 with Bartholin's abscess, 1 with pyometra (due to corpus cancer) were treated with SBT/CPZ at a dose of 1 g twice daily for 4-5 days by intravenous injection or intravenous drip infusion. The clinical response was good in all cases. A case with pyometra did not respond to the therapy in bacteriologically. Side effects and abnormal laboratory findings due to the drug were not noted.

Adult↗

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

Ceftazidime ( CAZ ), a new cephalosporin antibiotic, was fundamentally and clinically studied. The following results were obtained. Serum and internal genital tissue levels of CAZ were measured following intravenous drip infusion of 1 g for 30 minutes. Serum levels of more than 10 micrograms/ml and tissue levels of more than about 7 micrograms/ml were maintained after 2 hours to 2 hours and 30 minutes, respectively. Favourable transfer of CAZ into the pelvic dead space exudate was observed. The exudate level attained its peak of 31.54 micrograms/ml on average at 2 hours and was 16.8 micrograms/ml on average even at 8 hours after intravenous drip infusion. A total of 6 cases comprising 1 of adnexitis, 2 of pyometra, 1 of endometritis and 2 of parametritis was treated with CAZ at a dose of 0.5 approximately 2.0 g twice daily by intravenous injection or intravenous drip infusion. The clinical response was excellent in 1 case, good in 4 cases and poor in 1 case. Abnormal laboratory findings and side effects due to the drug were not noted.

Adult↗

Utility of egg yolk medium for cultivation of Mycoplasma pneumoniae.

Chicken egg yolk broth medium containing 10% (vol/vol) phosphate-buffered saline extract of egg yolk instead of horse serum showed better growth-promoting activity for Mycoplasma pneumoniae than did Chanock medium and was effective in promoting the growth of small numbers of M. pneumoniae. Moreover, the phosphate-buffered saline extract of egg yolk proved superior to horse serum in the following respects: (i) it was consistent in growth-promoting activity for M. pneumoniae among different batches; (ii) it could be preserved at 4 degrees C for at least 2 years; (iii) it is inexpensive and easy to obtain; and (iv) it contains large amounts of lipoproteins, cholesterol, and phospholipids.

Animals↗

[Effects of pentylenetetrazol on conflict behavior and interactions with anxiolytics in rats].

Effects of pentylenetetrazol (PTZ) on conflict behavior were studied using a punished water-lick (conflict) paradigm in rats. PTZ (5-20 mg/kg, ip) produced a dose-related enhancement of conflict behavior as demonstrated by a suppression of lick responding in low shock intensity (1.3-2.0 mA). Furthermore, PTZ (2-20 mg/kg, ip) clearly antagonized the release of punished responding induced by diazepam (5 mg/kg, ip), chlordiazepoxide (10 mg/kg i.p.) or meprobamate (75 mg/kg, ip) when a high intensity of shock (2.5 or 3 mA) was used. Bemegride also showed a similar suppressive effect on the anticonflict action of diazepam. However, bicuculline, picrotoxin or strychnine neither enhanced conflict behavior nor inhibited the anticonflict action of diazepam, even in high doses. In addition, PTZ (10 or 20 mg/kg, ip) did not show any significant effect on unpunished drinking or flinch-jump threshold, suggesting that the conflict enhancing action of PTZ may not be due to the secondary action including decrease in drive for drinking or increase in sensitivity to shock. These results suggest that PTZ may exert facilitation of conflict behavior or suppression of the anticonflict action of anxiolytics via an activation of the conflict generating mechanisms.

Animals↗

[Clinical trial of carmofur (HCFU) in the treatment of malignant ovarian cancer--The first report: combination therapy with endoxan, mitomycin C, and toyomycin].

A new fluoropyrimidine antitumor agent, carmofur (HCFU, Mifurol) was administered to patients with malignant ovarian tumor. Two of these patients revealed favorable results. The first patient was a 72-year-old female, who was diagnosed as having ovarian serous cystadenocarcinoma with metastatic omental tumor at exploratory laparotomy, its size was newborn child head size. She was started on with a combination chemotherapy of Mifurol (600 mg p.o. daily), Endoxan (4 mg/kg i.v. twice a week), Mitomycin C (0.04 mg/kg i.v. twice a week) and Toyomycin (0.01 mg/kg i.v. twice a week). After four weeks, this combination therapy brought her a complete response with disappearance of pleural effusion, ascites and metastatic tumor. The second case was a 39-year-old female, who underwent adnexectomy elsewhere which led to the discovery of Krukenberg tumor, and was referred to our hospital. After the first course of the same combination chemotherapy, second look operation was performed. Histological examination of the specimen obtained by metastatic tumor of uterosacral ligament showed the degeneration (grade II b-III, Oboshi and Shimozato) of cancer cell. It is suggested that this combination chemotherapy including Mifurol is effective and useful for the patients with ovarian carcinoma.

Adult↗

[Fundamental and clinical studies of T-1982 (cefbuperazone) in the field of obstetrics and gynecology].

T-1982 (cefbuperazone), a new cephamycin antibiotic, was fundamentally and clinically studied. The following results were obtained. Serum and internal genital tissue levels of T-1982 were measured following intravenous injection or intravenous drip infusion of 1 g. High serum levels of more than 10 micrograms/ml and tissue levels of more than 5 micrograms/g were maintained for 3 hours after intravenous administration. Favourable transfer of T-1982 into the pelvic dead space exudate was observed. The exudate level attained its peak at 2 hours and was 14.6 micrograms/ml on average even at 8 hours after intravenous infusion. With its MIC values, T-1982 was considered to be bactericidal against many Gram-negative bacteria except Pseudomonas sp. A total of 4 cases comprising 2 with pyometra, 1 with pelveoperitonitis and 1 with endometritis complicated with pelveoperitonitis was treated with T-1982 at a dose of 1-2 g twice daily by intravenous drip infusion. The clinical response was excellent in 1 case and good in 2 cases. A case with pyometra due to S. faecalis did not respond to the therapy. Side effects and abnormal laboratory findings due to the drug were not noted.

Adult↗

[Interaction with cholinergic drugs in reversal of cycloheximide-induced amnesia by thyrotropin-releasing hormone and its analog DN-1417 in mice].

The reversal effect of drugs on experimental amnesia was studied using one-trial passive avoidance task in mice. Cycloheximide (120 mg/kg) given sc 30 min before the acquisition of avoidance response caused amnesia by showing short latency to enter from the safety compartment into the shocked compartment in the retention test conducted 24 hours later. In these cycloheximide-treated animals, physostigmine (0.1 mg/kg), thyrotropin-releasing hormone (TRH: 10-20 mg/kg) and DN-1417 (5-20 mg/kg) given sc 15-60 min before the retention test markedly prolonged response latency, indicating reversal of amnesia. The effects of all these drugs were almost completely antagonized by anticholinergic drug, scopolamine (0.4-10 mg/kg). Although physostigmine when administered in conjunction with TRH potentiated the reversal effect, there was no potentiation with DN-1417. Since these drugs did not affect test performance in the cycloheximide-treated mice which had experienced no foot-shock, it is unlikely that the amnesia-reversing effect of the drugs was a result of non-specific suppression on motor activity. These results suggest that cholinergic activation reverses cycloheximide-induced amnesia, and TRH and DN-1417, while they showed a difference in the action of potentiation with physostigmine, may also activate a retrieval process of memory by mediation of cholinergic mechanism.

Amnesia↗

Behavior of Mycoplasma hominis in a human diploid cell culture system.

The behavior of Mycoplasma hominis in normal human embryonic lung fibroblast (HAIN-55) cell cultures was investigated. Multiplication patterns of cell-associated mycoplasmas and of extracellular mycoplasmas in the HAIN-55 cultures depended upon the size of the inoculum. This relationship did not vary with the number of days the cells had been cultured, nor with the number of HAIN-55 cell passages. The maximum mycoplasmal growth was obtained with inoculum sizes of 10(5) to 10(6) colony-forming units (CFU)/ml. The recovery of mycoplasmas decreased rapidly with inoculum size beyond 10(7) CFU/ml, and growth of the HAIN-55 cells was inhibited. Growth of the cells was also inhibited by the addition of the cytoplasmic fraction of Mycoplasma hominis.

Cell Line↗

Attachment of Mycoplasma hominis and M. orale to human diploid lung fibroblasts.

The process of attachment of Mycoplasma hominis and M. orale to HAIN-55 cells, derived from normal embryonic human lung, was investigated quantitatively. The attachment reached its maximum within about 2-4 hr at 37 degrees C and increased linearly as a function of the number of organisms present in the system. The relative attachment efficiency of M. hominis was approximately 1% under our experimental conditions. Trypsin and EDTA were effective in detaching particles of M. hominis and M. orale from the surfaces of HAIN-55 cells. Therefore it was suggested that some proteinaceous substance and salt bridges might be involved in the attachment of these mycoplasmas to HAIN-55 cells.

Adhesiveness↗

Uteroplacental blood flow and uteroplacental shunt rates in normal and prolonged pregnancies in rats.

To reveal the regulatory function in uteroplacental blood flow we measured, using the method of double tracer microspheres, the rates of uteroplacental blood flow (UPBF) and uteroplacental shunt (UP-shunt) in SD-strain rats of normal and prolonged pregnancy. (1) In the group of rats of normal pregnancy, the rate of UPBF attained a peak on the 20th day of gestation, while the UP-shunt rate was highest on the 18th day of gestation. (2) In the progesterone-induced prolonged pregnancy group, the rate of UPBF remained at an 8% level until the the 22nd day, i.e., the first day of prolonged pregnancy, and dropped to 6.6% on the 23rd day. The UP-shunt rate in the progesterone-administered group was about 27% on the 20th day, more favorable than the corresponding rate in the normal group, but thereafter rapidly decreased. The rate of increase in fetal body weight in this group became lower, showing a fetal death rate of 4.6%. (3) The decreases in placental alkaline phosphatase and leucine aminopeptidase examined as markers of placental function lagged behind the fall in the UP-shunt rate. On the 23rd day of gestation when the rates of UPBF and UP-shunt dropped, the decreases in their placental enzyme activities were remarkable.

Alkaline Phosphatase↗