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Biomedical subjects

R Saito

Publications and source records attributed to R Saito.

At least 199 records · Page 11Linked to original sources
PubMed1992

Role of NK-1 receptor in central cardiovascular regulation in rats: studies on a novel non-peptide antagonist, CP-96,345, of substance P NK-1 receptor.

CP-96,345[(2S,3S)-cis-2-(diphenylmethyl)-N-[(2-methoxyphenyl)- methyl]-1-azabicyclo [2.2.2] octan-3-amine] was recently discovered to be a nonpeptide substance P (SP) antagonist. We examined the effects of CP-96,345 on the central cardiovascular responses to tachykinin peptides in anesthetized rats. CP-96,345 (200 nmol, i.c.v.) inhibited the pressor responses of the NK-1 receptor-selective agonist GR 73632 (0.5 nmol, i.c.v.) and SP (7 nmol, i.c.v.). It also inhibited the increase in blood pressure elicited by neurokinin A (7 nmol, i.c.v.). However, it had no effect on the earlier pressor response induced by neuropeptide gamma (l nmol, i.c.v.) or by a selective NK-3 agonist senktide (1 nmol, i.c.v.). These findings suggest that SP (i.c.v.) induces pressor responses via the NK-1 receptor, and that the pressor response to neurokinin A may also be mediated by the NK-1 receptor in the brain.

Animals↗
PubMed1992

Reversibility of energy metabolism and intracellular pH after cerebral ischaemia evaluated by 31P-MRS.

We have previously developed a reproducible model of transient forebrain ischaemia in rats by bilateral carotid artery occlusion combined with temporary increase of ICP. With this model, reversibility of the energy metabolism and intracellular pH (pHi) was investigated by 31P-MRS during 120 min of recirculation in three groups of, respectively, 30, 60, and 120 min of ischaemia. With the induction of ischaemia, ATP and phosphocreatine (PCr) disappeared, and measurement of pHi showed severe acidosis in all rats. In the 30 min ischaemia group, both energy metabolism and pHi recovered almost completely. In the 60 min ischaemia group, ATP recovered to 74% of control values, but pHi showed full recovery. In the 120 min ischaemia group, ATP recovered to about 50% of control values, and recovery of pHi was variable. Showing logarithmical changes during recirculation in ATP and PCr, the rate of metabolic recovery was fast during 60 min of recirculation, but it decreased and reached plateau thereafter in all groups. Recovery of pHi was affected by ATP levels, and was precipitously accelerated as ATP levels exceeded 50% of pre-ischaemic values. These results suggest that prolongation of the duration of ischaemia limits the restoration of the energy state, and the quality of pHi recovery after cerebral ischaemia is affected by the degree of ATP recovery during 60 min of recirculation.

Adenosine Triphosphate↗
PubMed1992

The crystal structure and absolute configuration of the antitumor platinum complex trans(OH)-Pt(OH)2(malonato)(1R,2R-cyclohexanediamine).

The absolute configuration of the anti-tumor complex trans(OH)-Pt(OH)2(malonato)(1R,2R-cyclohexanediamine) was determined by X-ray anomalous scattering technique. The final unit cell was monoclinic, space group P2(1) with a = 9.142 A, b = 7.788 A, c = 11.946 A, beta = 96.48 degrees, Z = 2. The crystal structure was determined by direct method and difference Fourier synthesis, and refined to R = 0.025 and Rw = 0.033 based on 2768 independent reflections. The platinum atom has roughly octahedral coordination. The cyclohexane ring has the expected chair configuration, with two amino groups in equatorial positions while the malonato ligand, in contrast, shows a boat conformation for six membered Pt O-C-C-C-O ring.

Antineoplastic Agents↗
PubMed1992

[Establishment of an outbred strain (Jic: SUN) in the house musk shrew, Suncus murinus].

Planned reproduction of the house musk shrew, Suncus murinus was investigated using 3,016 females for mating. The birth rate and the weaning rate attained were 77.2% and 82.3%, respectively. The average litter size was 3.4. The mean value of the productive index (number of weaned individuals/number of females mated) was estimated as 2.2. The highest value of the productive index, 2.6, was recorded when the fourth litter was used for reproduction. No seasonal fluctuation in the reproductive ability was observed through the course of the present breeding. In the present study, we have maintained the closed colony of the house musk shrew for six years. This colony is established as a outbred strain, and is designated as Jic: SUN.

Animals↗
PubMed1992

Detection of human papillomavirus type 6f genome in nasal papillomatosis.

Five cases of nasal papillomatosis were studied clinicopathologically and virologically. In a case of recurrent papillomatosis of non-inverted type located on the nasal septum, human papillomavirus (HPV) DNA was detected by dot blot hybridization with an RNA cocktail probe of mucosal HPVs. In Southern blot hybridization, the DNA hybridized with that of HPV types 6 and 11 but not with those of types 16 and 18. Its restriction endonuclease-cleavage patterns corresponded well to those of HPV type 6f. These results suggested that HPV type 6 would also be associated with nasal non-inverted papillomatosis.

Blotting, Southern↗
PubMed1992

[Traumatic intracranial aneurysms after removal of tuberculum sellae meningioma: case report].

Two cases of traumatic aneurysms (TA) of the internal carotid artery (IC) due to removal of tuberculum sellae meningioma (TSM) are presented, and ideal treatment of those aneurysms is discussed. The tumor, compressing the IC laterally, was removed out without arterial injury in case 1. Though the patient's postoperative course was uneventful, frontal and intraventricular hemorrhage developed 2 months after the operation, and an IC dorsal aneurysm was detected. Preoperative angiograms showed no aneurysm, so it was considered to be a traumatic aneurysm due to the surgical procedure. The aneurysm was clipped at once, but postoperative angiograms showed recurrence of the aneurysm. IC balloon occlusion was carried out as the Matas test was negative. In case 2, a small tear in the IC was inadvertently made during recurrent TSM removal, which was wrapped with muscle using fibrin glue. 2 weeks after the operation, frontal hemorrhage developed. Angiograms revealed a small aneurysm of the IC, which was considered to be a traumatic aneurysm. IC balloon occlusion was performed as the Matas test was negative. These 2 patients have had no episodes of rerupture after the IC balloon occlusion. Tumors and main arteries are frequently adhesive, so arteries are easily injured during removal of meningiomas. Muscle wrapping was not enough to prevent TA formation. Neck clipping was not appropriate for treatment of TA, but IC balloon occlusion was an effective and excellent therapy for TA of IC.

Adult↗
PubMed1992

[A case of mediastinal vagal nerve neurinoma: a familial neurinomatosis].

We experienced an operation of a 16-year-old female of mediastinal vagal neurinoma. Abnormal shadow was pointed out on chest X-ray at physical examination of high school. Right thoracotomy was performed under the diagnosis of mediastinal tumor. There was a walnut sized mass on the right vagal nerve at just peripheral side of the recurrent nerve branch. The vagal nerve was cut at both sides of the mass not to injure the recurrent nerve. The tumor was removed en block. Two little finger sized masses were recognized in serratus anterior muscle and 5 th. intercostal nerve. These removed masses were diagnosed as neurinoma pathologically. While the mother of this case had been admitted on another hospital because of multiple neurinomatosis with bilateral acoustic neurinoma. Thus this case is of familial neurinomatosis, suggesting it's heredity like as neurofibromatosis (von Recklinghausen's disease).

Adolescent↗
PubMed1991

Prognostic factors in the treatment of hepatocellular carcinoma with transcatheter arterial embolization and arterial infusion.

From January 1986 to December 1988, a prospective trial of transcatheter arterial treatment was carried out for hepatocellular carcinoma (HCC). Two hundred seventy-five patients were included. Okuda's staging system was employed. Patients with Stage I and II HCC were treated by transcatheter arterial embolization (TAE) with a gelatin sponge containing an anti-cancer agent (protocol 1a); a gelatin sponge and iodized oil mixed with an anti-cancer agent (protocol 1b); or iodized oil mixed with an anti-cancer agent (protocol 2). Patients with Stage III HCC were treated with iodized oil with anti-cancer agent (protocol 2). As an exception, patients with an unsuccessful superselective catheterization into the proper hepatic artery by Seldinger technique or obstruction of the main trunk of the portal vein were treated with percutaneous transcatheter arterial infusion into the common hepatic artery regardless of stage (protocol 3). Tumor type and extension, area of tumor involvement, portal vein involvement, method of treatment, and presence of ascites and icterus were found to be the significant factors for an initial response to therapy. Treatment method was the most important factor. Respective survival rates at 1 and 2 years were 70.9% and 55.3% for protocol 1a; 62.3% and 43.8% for protocol 1b; 37.8% and 18.3% for protocol 2; and 16.5% and 0% for protocol 3. Many factors proved to significantly influenced prognosis; however, tumor type had the most important prognostic significance followed by AFP value, ascites, treatment protocol, and area of tumor involvement.

Adult↗
PubMed1991

Monkey model of severe volume-controlled hemorrhagic shock with resuscitation to outcome.

Seventeen cynomolgus monkeys under N2O analgesia and sedation were subjected to severe volume-controlled hemorrhagic shock (shed blood volume of 21 or 27 ml/kg). In 12 monkeys, resuscitation was started after increasing periods of hemorrhagic shock from 30 min to 5 h. In five additional monkeys, volume-controlled hemorrhage was modified at hemorrhagic shock 30 min to control MAP at 30 mmHg: resuscitation was started at hemorrhagic shock of 2 h. A clinically relevant resuscitation protocol consisted of a field phase from 0 to 6 h (lactated Ringer's solution, spontaneous breathing), and a hospital intensive care phase from 6 h to 48 h (blood, lactated Ringer's solution to mean arterial pressure (MAP) greater than or equal to 70 mmHg, controlled ventilation, advanced life support). Fifteen of the 17 monkeys survived. After outcome evaluation at 4 or 7 days, the eight monkeys with "moderate insult" had only transient functional impairment. Of the nine with "severe insult," three showed signs of moderate transient non-oliguric renal failure. Eight of the 12 monkeys studied morphologically showed scattered liver cell damage. None of the monkeys developed pulmonary dysfunction or functional or morphologic evidence of cerebral damage. This study establishes a new hemorrhagic shock-resuscitation model simulating field-to-hospital life support. Severe hemorrhagic shock with MAP 30-40 mmHg for 90-120 min (without trauma or sepsis) can lead to complete functional recovery after transient malfunction of liver and kidneys.

Animals↗
PubMed1991

Resistance of female Fischer-344 rats to the hepatonecrogenic and hepatocarcinogenic actions of a choline-devoid diet.

A series of experiments was performed to investigate the response of female Fischer-344 rats to a choline-devoid (CD) diet. In contrast to findings previously made in male Fischer-344 rats, hepatocellular carcinomas did not develop in females chronically fed the diet. Their liver actually showed only minimal histopathological changes. For these reasons, the steatogenic and hepatonecrogenic actions of a CD diet were compared in male and female Fischer-344 rats. Young adult females were found to be largely resistant to both. The results were taken as further evidence of the primary and essential role played by an enhanced cell turnover in the pathogenesis of the carcinomas induced in male Fischer-344 rats by this non-chemical, nutritional model of hepatocarcinogenesis. A high incidence of preneoplastic and benign lesions developed in breast, pancreas or stomach of females chronically fed the CD diet. However, a similar spectrum and high incidence of lesions was observed in control rats fed a choline-supplemented diet. These findings were attributed to an enhanced occurrence of spontaneous lesions, most likely due to the high fat content (15%) of the two diets used.

Animals↗