Biomedical subjects

Y Naka

Publications and source records attributed to Y Naka.

At least 91 records · Page 5Linked to original sources

PubMed1991

[Selective vulnerability of peptide-containing neurons in cerebral ischemia; immunohistochemical study].

Histochemical changes in peptidergic and catecholaminergic neurons during ischemia were investigated in the cerebral neocortex of the gerbil. Catecholaminergic fibers were observed by catecholamine histofluorescence with glyoxylic acid solution, and peptidergic neuron systems such as vasoactive intestinal polypeptide (VIP), somatostatin (SOM), and neuropeptide Y (NPY) were observed by immunohistochemistry. Two hours after unilateral occlusion of the internal carotid artery, catecholaminergic fibers disappeared in the neocortex on the occlusion side, while peptidergic nerve fibers except for NPY fibers were intact after 2 hours of ischemia. NPY fibers had decreased in number on the occlusion side 2 hours after ischemia. VIP-, SOM-, and NPY-immunoreactive neurons showed a decrease of 60% six hours after ischemia, and these neurons completely disappeared in the cerebral neocortex 24 hours after ischemia. These results suggest that catecholaminergic neuron system is more vulnerable than the peptidergic one in ischemic event.

Animals↗

PubMed1991

[Intrascrotal leiomyoma: report of a case].

A case of intrascrotal leiomyoma is reported. The patient was a 56-year-old male who complained of painless mass in the scrotum. He noticed the mass about 10 years ago and it had gradually enlarged. The mass was removed surgically. Pathohistological diagnosis of the specimen was leiomyoma. The literature revealed 13 cases of intrascrotal leiomyoma in Japan.

Genital Neoplasms, Male↗

PubMed1991

[A case of uretero-vaginal fistula with ureteral foreign body stone originated from the suture thread].

A 32-year-old female was admitted to our hospital with the chief complaint of vaginal discharge of urine. She had undergone radical hysterectomy due to uterine cancer at another hospital by a gynecologic surgeon 5 years earlier. X-ray examination showed a stone-like shadow at the left ureter without hydronephrosis. She was diagnosed with ureterovaginal fistula with the left ureteral stone. Left ureterolithotomy and ureterovesiconeostomy was performed. The stone revealed a foreign body stone originating from the silk worm-gut which had penetrated accidentally the ureter when the vaginal wall was sutured at the previous surgery. Including our case, 15 cases of foreign body stones in the upper urinary tract were found in the Japanese literature and none of them were associated with ureterovaginal fistula.

Adult↗

PubMed1990

Canine heart-lung transplantation after 24-hour hypothermic preservation.

We compared the efficacy of Belzer UW solution (UWS) with modified Collins solution (MCS) in a 24 h canine heterotopic heart-lung transplantation model. Nine pairs of mongrel dogs were divided into 2 groups: MCS group (n = 5) and UWS group (n = 4). The donor heart was arrested with cardioplegia. The heart and lung were flushed with MCS or UWS, excised en bloc and immersed in 4 degrees C MCS or UWS for 24 h. Graft function was adequate in 1 of 5 grafts in the MCS group and in all 4 grafts in the UWS group (P less than 0.05). In the UWS group, the prepreservation and posttransplantation cardiac output was 71.2 +/- 21.6 and 96.4 +/- 44.4 ml/min per kg, the PaO2 was 80.8 +/- 12.9 and 74.1 +/- 2.7 mmHg, and the PaCO2 was 25.6 +/- 5.5 and 35.9 +/- 13.3 mmHg, respectively. No difference was significant. In the UWS group, the pulmonary vascular resistance increased significantly to 13.8 +/- 3.7 from 8.8 +/- 5.2 Wood units (P less than 0.05). Post-transplantation myocardial water content in the UWS group (78.6 +/- 2.0) was less than in the MCS group (81.1 +/- 1.4, P less than 0.05). The wet/dry ratio of the lung increased significantly to 8.3 +/- 1.6 from 4.4 +/- 0.6 in the UWS group (P less than 0.01) and to 10.3 +/- 0.8 from 4.1 +/- 0.1 in the MCS group (P less than 0.01), but was less in the UWS group (P less than 0.05). These results suggest that UWS is more effective than MCS in 24 h heart-lung preservation, but does not prevent pulmonary oedema adequately.

Animals↗

PubMed1990

Prolonged preservation of cadaver heart with Belzer UW solution: 24-hour storage system for asphyxiated canine hearts.

The efficacy of Belzer UW solution was compared to Collins' solution in the preservation of asphyxiated cadaver hearts in a canine model. Donor hearts were stored for 24 h: 2 h of in situ hypothermic (15 degrees C) coronary perfusion plus 22 h of simple immersion in ice-cold solution. Verapamil, propranolol and prostacyclin were used for myocytoprotection in both groups. After orthotopic transplantation, all animals were weaned off bypass without inotropic support. After 1 h, however, the cardiac output was significantly higher in the Belzer UW solution group (128 +/- 28 vs. 67 +/- 13 ml/kg/min, p less than 0.01).

Adenosine↗

PubMed1990

Autologous transplantation of the superior cervical ganglion into the brain of parkinsonian monkeys.

The effect of autologous transplantation of the superior cervical ganglion (SCG) into the brain of parkinsonian monkeys was studied through quantitative measurement of animal behavior. The motor activity of the monkey was measured with a telemetry system during the experiment. After experimental parkinsonism was induced by repeated intravenous injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), three monkeys were treated with autologous transplantation of the SCG into both caudate nuclei. One monkey served as a control without SCG transplantation after MPTP treatment. Three SCG-transplanted monkeys showed biphasic (acute and chronic) behavioral amelioration of parkinsonism after transplantation. In the acute stage, the animals showed transient hyperkinesia with aggressive behavior and loss of circadian rhythm. In the chronic stage following acute hyperkinesia, the animals regained normal behavior and circadian rhythm without aggressiveness. In contrast with the transplanted monkeys, the control monkey failed to show recovery of the bradykinesia and muscle rigidity.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1990

[Frequency of food intake of dentulous and complete denture wearers].

The study was carried out on 1466 subjects, whose ages ranged from 20 to 80 years of age, of whom 1181 were dentulous and 285 were complete dentures. We studied the frequency with which the 1466 cases partook of food. The results were as follows: 1) Ingested foods were classified into 10 groups along with the frequency with which they were ingested on a yearly seasonal basis. Food groups were classified as follows: vegetables, grain, sea food, beans, meat, seaweed, potatoes, fruits, etc. 2) The Ingested foods of the dentulous group were similar to those of the complete denture wearers. 3) In all age groups the foods most ingested were: steamed rice, wakame, tofu, bread, scallions, Japanese omelette, and tomatoes. 4) The younger subjects (20 to 39 years) statistically ate significantly lower amounts of steamed rice than did the older age groups. 5) The younger generation ate more meat, while the older groups ate more sea food.

Adolescent↗

PubMed1989

Prevention of pulmonary edema developing in autoperfusing heart-lung preparation by leukocyte depletion.

We investigated the preventive effect of leukocyte depletion on the development of pulmonary edema in a 12 h autoperfusing heart-lung preparation (AHLP). Sixteen mongrel dogs were divided into two groups: control group (group C, n = 9) and leukocyte depleted group (group L, n = 7). In group L, leukocytes were depleted with a leukocyte removal filter prior to the preservation. Extravascular thermal volume (EVTV) was measured by thermal-dye dilution technique as a parameter of pulmonary edema during preservation. The white blood cell (WBC) count was measured before and during preservation. After the procedure, extravascular lung water (EVLW) was measured by a gravimetric technique. In group C, the WBC count significantly decreased soon after the start of preservation, and subsequently remained without significant changes. In group L, the WBC count was maintained at a low level during the entire course of preservation. In group C, EVTV increased significantly with the preservation time. In group L, a significant increase in EVTV was only found at 12 h to a smaller extent than in group C. EVLW was significantly smaller in group L than in group C. In conclusion, the development of pulmonary edema was apparently prevented in the 12 h canine AHLP model by leukocyte depletion, and pulmonary leukocyte sequestration was considered as a cause of pulmonary edema in AHLP.

Animals↗

PubMed1989

[Thromboxane synthetase inhibitors. I. Synthesis of some imidazolylarylmethanols and their inhibitory activity on platelet aggregation].

Several imidazolylpyridinemethanols and imidazolylbenzenemethanols were prepared and evaluated for an inhibitory activity against arachidonic acid-induced platelet aggregation. The result shows that the arylmethanol moiety is essential for the activity and may correspond to the 15-OH group of prostagrandin H2 (PGH2). Among the compounds tested, 4-[alpha-hydroxy-5-(1-imidazolyl)-2-methylbenzyl]-3,5-dimethylbenzoic acid (XV) was found to have a potent inhibitory activity and a long duration of action. Structure-activity relationships are also discussed briefly.

Animals↗

PubMed1989

[Effects of articulating paper on mandibular paths in lateral and protrusive excursions].

Mandibular movements in 7 normal dentulous subjects during lateral and protrusive excursions were studied to investigate the effects of the clinical use of articulating paper on mandibular paths. Mandibular movements with or without the intraoral articulating paper (thickness: 35 microns) were detected as the lower incisal point displacement and were recorded three-dimensionally with the Selspot system. The date displayed on the X-Y chart recorder on the selected plane were analyzed quantitatively. 1. The paths of the mandible differed between the outward (from the intercuspal position) and the return (backward to the intercuspal position) movements. In lateral excursions the return path tended to be antero-inferior to the outward path, whereas in protrusive excursions the former tended to be dextro-inferior to the latter. 2. In lateral excursions the return path tended to be less stable than the outward path. In protrusive excursions no significant difference was found between the two paths. 3. In lateral excursions, 21-34% of the movements performed using the articulating paper deviated from the normal paths made without using the paper, and in the case of protrusive excursions, deviation was found in 21-50%. At or near the intercuspal position, the return path showed a greater deviation than the outward path. Near the edge-to-edge position, however, the relationship between these two path was reversed. 4. It is suggested that, when the articulating paper is used, the directions of the movement should be taken into account and sufficient care should be paid in occlusal adjustment because the range of functional movement may be overestimated.

Dental Occlusion↗

PubMed1989

[Umbilical blood-gas status at cesarean section for breech presentation: a comparison with vertex presentation].

Umbilical blood-gas status at elective cesarean section with oxygen inhalation for breech presentation (25 cases) was compared with that for vertex presentation (25 cases), so as to confirm the security of full-term breech fetuses delivered by cesarean section under spinal anesthesia. Umbilical arterial oxygen levels were significantly lower in the breech group (Mean PO2:18.9 mmHg; SO2:37.3%; Oxygen content:7.6 ml/dl). The number of hypoxemic fetuses was significantly higher in the breech group (the breech: 7; the vertex; 0). The other umbilical blood-gas values revealed no significant differences between the breech and vertex groups, and were within normal limits in both groups. Oxygen extraction in the breech (Mean: 49.0%) was higher than that in the vertex (32.9%). Therefore decreased umbilical blood flow in the breech was suggested. The incidence of depression at 1 minute after delivery in the breech infants (24%) was significantly higher than that in the vertex infants (0%). It became obvious in the breech that as the interval between the uterine incision and delivery increased, umbilical arterial blood tended to acidosis and the 1 minute Apgar score decreased. Cesarean section for breech presentation requires sufficient and optimal incisions of the abdominal wall and uterus as well as a skillful manual delivery technique, because the fetus or neonate should be protected against asphyxia resulting from umbilical compression and prolonged delivery interval.

Adult↗

PubMed1989