Search PubMed⌕ Search

Biomedical subjects

S Ohara

Publications and source records attributed to S Ohara.

304 records · Page 17Linked to original sources
PubMed1976

[Maxillary artery to middle cerebral artery anastomosis in dog-- a new experimental model (author's transl)].

End-to-side anastomosis between the maxillary artery and a branch of the middle cerebral artery was performed in the dog. The technique was devised as a new experimental model for extracranial-intracranial arterial shunt operation. The middle cerebral artery was ligated at the origin through a subtemporal small burr hole under the operating microscope in 13 dogs. Then, the shunt operation was carried out in 8 dogs 4 hours after the ligation(acute state), and in 5 dogs 3 weeks after(chronic stage). The patency of the anastomotic site was evaluated by the selective external carotid angiography 2 weeks after the shunt operation. In the acute stage of 8 dogs, 7 cases showed patency of anastomosis (88%), and in the chronic stage of 5 dogs, arteriogram revealed 4 patent anastomosis (80%). In successful cases, arteriogram showed excellent filling of the entire territory of the middle cerebral artery through the shunts (Fig. 4, 5). Various types of experimental shunt operation were attempted in our review of the literature. Among them, the anastomosis between the superficial temporal artery and a branch of the middle cerebral artery by Yasargil (1967) is rather popular and this procedure has been used by some investigators including us to investigate the effect of the extracranial-intracranial shunt on experimental acute stroke. So far as dog's experiment is concerned, the superficial temporal artery appeared to be not suitable for a donor artery, because the superficial temporal artery runs far from the middle cerebral artery and its distal part is extremely small in caliber. Therefore, the superficial temporal artery was often obstructed by compression, kinking or narrowing by surrounding tissues and by adhesion to the bone edge of the burr hole. On the other hand, the maxillary artery of the dog, which is the largest terminal branch of the external carotid artery, has plenty of blood flow and suitable size for end-to-side anastomosis to the middle cerebral artery. In addition, maxillary artery is located very close to the proximal part of the middle cerebral artery. These anatomical and spatial advantage of the maxillary artery seemed to be favorable donor artery to the middle cerebral artery and have brought hight patency rate in our series of anastomosis than that of the other previous experimental extracranial-intracranial shunts. To our knowledge, this is the first report on successful patent shunt formation after long-term occlusion of the middle cerebral artery in animals. Now, it is in our mind that progress of the study can be expected in the field of extracranial-intracranial shunt operation for cerebral infarction by this experimental procedure.

Animals↗
PubMedDate not supplied

Effect of esmolol on hemodynamics and intraocular pressure response to succinylcholine and intubation following low-dose alfentanil premedication.

STUDY OBJECTIVE: To determine the effectiveness of esmolol hydrochloride (Brevibloc) as an additional adjunct to low-dose alfentanil premedication in controlling the hemodynamic response [heart rate (HR), mean arterial pressure (MAP), and intraocular pressure (IOP)] to succinylcholine and endotracheal intubation. DESIGN: Randomized, double-blind, placebo-controlled, prospective study. SETTING: Ambulatory gynecologic surgery at a university medical center. PATIENTS: Twenty ASA physical status I and II female patients scheduled for outpatient laparoscopy under general anesthesia. INTERVENTIONS: All patients received alfentanil 10 micrograms/kg as a preoperative medication 4 minutes prior to induction of anesthesia. Study patients (n = 10 in each group) received either esmolol 1.5 mg/kg or a placebo (normal saline) 30 seconds prior to induction (210 seconds after alfentanil and 90 seconds prior to endotracheal intubation). Anesthesia was induced with thiopental sodium 5 mg/kg and succinylcholine 1 mg/kg. Postintubation, 70% nitrous oxide, 30% oxygen, and 1% isoflurane were administered. MEASUREMENTS AND MAIN RESULTS: Time of study drug administration was defined as time zero. Measurements of HR, MAP, and IOP were made at baseline (patient awake) and at each minute from minutes 1 through 6 after administration of the study drug (time zero). Analysis of variance was used to analyze the data, with a value of p less than 0.05 considered significant. Esmolol 1.5 mg/kg was found to blunt the maximum increase in HR but not MAP or IOP following low-dose alfentanil premedication. CONCLUSIONS: In an eye patient with coronary artery disease, or in any patient in whom tachycardia may be detrimental, esmolol may be a useful adjunct in combination with low-dose alfentanil to attenuate the increase in HR due to laryngoscopy and endotracheal intubation.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Schwann cell responses during regeneration after one or more crush injuries to myelinated nerve fibres.

The responses of Schwann cells during regeneration of myelinated nerve fibres were studied ultrastructurally in the distal segment of mouse phrenic nerve after a single or repeated localized crush injury. Chronological observations on nerves after a single crush confirmed the occurrence of myelination of only single regenerating axons among many that appeared in individual Büngner bands. The redundant axon sprouts often showed the structural features of degeneration and decreased in number with time. During the process, supernumerary Schwann cells not related to myelin formation were produced. They commonly failed not only to make a one-to-one relationship with an axon, but they also failed to acquire a new basal lamina of their own. With time, they showed shrinkage of their cytoplasm and became arranged circumferentially around the myelinating axon with unipolar or bipolar cytoplasmic processes. Electron microscopic, quantitative assessment of the nuclear population of Schwann cells following repeated crushes up to four times, clearly indicated a progressive and predominant increase in the number of the supernumerary Schwann cells with the number of crushes. Also, they were found to form separate concentric cytoplasmic lamellae around the myelinating axons, developing structures resembling onion-bulbs. It was concluded that essentially the same regenerating process as that observed after a single crush was repeated following re-crush, thereby resulting in the successive accumulation of supernumerary Schwann cells around a myelinating axon.

Animals↗
PubMedDate not supplied

Asymmetric tonic seizures with bilateral parietal lesions resembling frontal lobe epilepsy.

We performed long-term video/ EEG monitoring and a single photon emission computed tomographic (SPECT) study to clarify generating mechanism of bilateral tonic motor seizures resembling seizures generated by the supplementary motor area (SMA), in patients with bilateral parietal lesions. We describe 2 patients (age 24 and 32 years), with bilateral parietal lesions. Clinically, seizures were preceded by lightning sensation in the body, followed by asymmetric tonic posturing of both hands and thrashing movements of the feet, lasting for less than 1 min. Ictal rhythmic (7-15 Hz) activity at the vertex was observed on the EEG in 1 patient. Interictal SPECT in 2 patients showed decreased blood flow in both parietal areas, consistent with bilateral parietal abnormalities on T2- and T1-weighted MRIs. Ictal SPECT in 1 patient showed increased blood flow in the right parietal and frontopolar areas. The present 2 patients had clinically asymmetric tonic seizures, most likely resulting from spreading of the ictal activity from the parietal lesions via the superior longitudinal fasciculus to the SMA. Bilateral, homologous lesions in the parietal area might cause disinhibition on the unilateral epileptogenic side.

Adult↗
PubMedDate not supplied

Intrathoracic omental herniation through the esophageal hiatus: a case report.

A case of paraesophageal omental herniation in a 74-year-old man is reported. Although computed tomography (CT) and magnetic resonance imaging (MRI) depicted a retrocardiac fatty mass that resembled omental herniation, residual concern remained regarding lipomatous tumor. Angiography provided decisive evidence of a mass containing omental vessels passing through the esophageal hiatus, which led to the final diagnosis. The patient underwent a strict course of observation, because he had no symptoms or abnormal physical or laboratory findings. Paraesophageal omental herniation mimics lipomatous tumors, such as lipoma or well-differentiated liposarcoma, extending to both sides of the diaphragm. Correct diagnosis of omental herniation requires the evidence of omental fat accompanied with omental vessels passing through the esophageal hiatus. Since angiography is an invasive diagnostic procedure, we would recommend dynamic MRI or reconstructed 3D MR angiography as alternatives to angiography.

Aged↗
PubMedDate not supplied

Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome in Nagano, Japan: clinical, radiological, and cytokine studies of 13 patients.

OBJECTIVE: Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) has so far been reported almost exclusively from the USA and Europe. We carried out this study to define the clinical characteristics of this syndrome in Japanese patients. METHODS: Prospectively, we identified 13 Japanese patients with RS3PE (5 men and 8 women, age 72.7 +/- 11.8 years (mean +/- SD)) without underlying neoplasm. Their clinical features were summarized, pertinent laboratory data including serum/synovial interleukin-6 (IL-6) concentrations were obtained, and extensive radiologic studies using magnetic resonance imaging and 67gallium-citrate (67Ga) whole body scintigram were performed. RESULTS: All patients suffered from proximal arthralgia/myalgia in addition to typical distal symptoms of RS3PE, and all experienced systemic symptoms such as fever, malaise, and weight loss. In laboratory examinations, anemia and elevated inflammatory markers were often remarkable. Magnetic resonance imaging showed severe tenosynovitis of the hands. 67Ga-scintigram revealed radioisotope accumulation in both proximal and distal joints of the extremities. IL-6 activity was markedly elevated both in the serum (mean 82.4 +/- 62.1 (SD) pg/ml, normal range 0.157-2.94) and in the synovial fluid (mean 3350 +/- 633 (SD) pg/ml). CONCLUSION: Compared with cases reported previously from the USA/Europe, Japanese patients with RS3PE are characterized by more prominent systemic symptoms/signs associated with marked inflammatory responses including elevated IL-6 activity. All patients had proximal as well as distal synovitis which could be demonstrated by 67Ga-scintigram. These clinical features were very similar to those of polymyalgia rheumatica, suggesting that RS3PE and polymyalgia rheumatica are closely related disorders which may have a common pathogenesis.

Aged↗
PubMedDate not supplied

A case of psychogenic tremor associated with blepharospasm and myoclonus: an analysis with surface electromyogram.

We report a 25-year-old woman with an unusual complex psychogenic movement disorders consisting of blepharospasm, tremor, and myoclonus. The tremor appeared in both arms and legs with resting, kinetic, and postural tremor of a variable amplitude, direction, and frequency. The analysis of the arm tremor with surface electromyogram revealed that it consisted of reciprocal and alternating contraction of the wrist flexor and extensor. No apparent co-activation of agonist-antagonist muscles could be seen at the onset of the tremor at rest or at its appearance while performing diadochokinesis.

Adult↗
PubMedDate not supplied

Effects of omeprazole on rat gastric mucus glycoproteins with acetylsalicylic acid-induced gastric damage.

Investigations were carried out to determine the effects of omeprazole on mucus glycoprotein in rat gastric mucosa. Quantitative and qualitative changes in mucus glycoprotein, isolated from omeprazole-treated rats with or without acetylsalicylic acid-induced gastric damage, and the degree of gastric mucosal injury were studied. Omeprazole, in a dose-dependent manner, prevented macroscopical mucosal damage induced by acidified acetylsalicylic acid. A considerable decrease in corpus mucus glycoprotein (54%) and antral mucus glycoprotein (72%) was observed in acetylsalicylic acid-treated rats and acetylsalicylic acid reduced the amounts of fucose and galactose of corpus mucus glycoprotein. Pretreatment with omeprazole partially restored a quantitative reduction and a qualitative change of carbohydrate portion in corpus mucus glycoprotein induced by acetylsalicylic acid. A single administration of a high dose of omeprazole (200 mumol/kg) also induced the reduction of corpus mucus glycoprotein content (82%), although no changes in the carbohydrate component were observed. The decrease in corpus mucus glycoproteins induced by omeprazole might be due to a cause different from that of acetylsalicylic acid-induced mucus glycoprotein reduction.

Animals↗
PubMedDate not supplied

Usefulness of direct coronal CT in the diagnosis of urinary bladder tumor.

Direct coronal CT was performed on 6 cases of urinary bladder tumor in which conventional axial transverse CT failed to depict the relationship between the lesion and bladder wall. GE CT/T 8800 was used, and the bladder was scanned with patients crouched on the table opposite the gantry. The relationship between the tumor and bladder wall as well as the surrounding organs was visualized in 5 of 6 cases examined. THe CT diagnosis and histological findings coincided in 4 of these 5. Direct coronal CT was useful for diagnostic determination of clinical stage for tumors occurring in the apical or basal region of the urinary bladder.

Humans↗
PubMedDate not supplied

Immunohistochemistry of Caspase3/CPP32 in human stomach and its correlation with cell proliferation and apoptosis.

Caspase3/CPP32 is a member of the interleukin-1 beta-converting enzyme (ICE) or cell death effector (CED)-3 family, which is involved in the induction of apoptosis and has been considered to be correlated with apoptosis because of the most downstream enzyme in their apoptosis inducing pathway. We immunolocalized Caspase3/CPP32 in both normal and neoplastic human gastric mucosa. We then correlated the findings with cell proliferation studied by Ki67 immunostaining and apoptosis, which was tested for by DNA fragmentation in situ using TdT-mediated dUTP biotin nick end labeling (TUNEL) method in order to examine possible biological significance in cell turnover of normal and pathological human gastric tissues. Caspase3/CPP32 immunoreactivity was detected in both the cytoplasm and nuclei of glandular epithelial cells, predominantly in the Ki67 positive proliferative zone and TUNEL positive foveolar epithelium of normal non-neoplastic gastric mucosa (n = 10) and tumor cells of both adenoma (n = 17) and carcinoma (n = 33). We determined the labeling index (LI) of Ki67, Caspase3/CPP32 and TUNEL positive cells by evaluating the number of positive cells in the same areas of serial tissue sections using computer-assisted image analysis. Ki67 LI in adenocarcinoma (78.6 +/- 12.6%) was significantly [p < 0.0001] higher than that of adenoma (43.8 +/- 8.9%) and non-neoplastic gastric mucosa (24.2 +/- 9.0%). Caspase3/CPP32 LI in adenocarcinoma (17.1 +/- 10.3%) was significantly lower [p < 0.0001] than that of gastric adenoma (33.1 +/- 19.8%) and non-neoplastic gastric mucosa (42.4 +/- 15.8%). TUNEL LI in adenocarcinoma (1.9 +/- 2.1%) was significantly [p < 0.0001] lower than that of non-neoplastic gastric mucosa (6.0 +/- 3.5%), but not significantly different from that of adenoma (3.0 +/- 2.9%). These results indicate that gastric adenocarcinoma is associated with an inhibition of apoptosis and the augmentation of proliferative activity of tumor cells compared to non-neoplastic gastric mucosa. There was a tendency to a positive correlation between the Caspase3/CPP32 and TUNEL LI and an inverse correlation between the Caspase3/CPP32 and Ki67 LI, when evaluating all the specimens, although the correlation did not reach statistical significance. These results also suggest that Caspase3/CPP32 is involved in the development or regulation of apoptotic cell death in cell turnover of normal and neoplastic mucosa of the human stomach.

Adenocarcinoma↗