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Biomedical subjects

M Sakai

Publications and source records attributed to M Sakai.

At least 361 records · Page 20Linked to original sources
PubMed1995

Intravenous injection of rabbit apolipoprotein A-I inhibits the progression of atherosclerosis in cholesterol-fed rabbits.

The effects of intravenous injection of purified rabbit apoA-I on the progression of aortic atherosclerosis in cholesterol-fed rabbits were examined. In experiment 1, 28 rabbits were equally divided into groups A and B and fed a 0.5% cholesterol diet for 90 days. For the last 30 days, group B received 40 mg apoA-I every week. The fatty streak lesions in group B (23.9 +/- 15.6%) were significantly suppressed compared with those in group A (46.0 +/- 24.9%) (P < .05). In experiment 2, 33 rabbits were divided into four groups (8 or 9 rabbits per group) and fed a 0.5% cholesterol diet. Group A was killed on day 105, while groups B, C, and D were maintained for an additional 60 days on a normal diet, during which time groups C and D received 1 mg apoA-I every other day or 40 mg apoA-I every week, respectively. The lesions in group C (70.2 +/- 15.4%) and group D (65.7 +/- 20.0%) were significantly suppressed compared with those in group B (86.2 +/- 13.7%) (P < .05) but were not reduced to the level of group A (50.0 +/- 22.9%). Although apparent regression was not observed under these conditions, the present study provided the first evidence for the antiatherogenic effect of homologous and apoA-I on the progression of atherosclerosis in cholesterol-fed rabbits.

Animals↗
PubMed1995

Induction of heparin-binding epidermal growth factor-like growth factor mRNA in rat kidney after acute injury.

Previous studies have suggested that EGF or other members of the EGF family of mitogenic proteins are involved in proliferation of renal tubular epithelial cells occurring during recovery from injury to the kidney. The present studies examined whether expression of mRNA for the recently identified heparin-binding EGF-like growth factor (HB-EGF) is regulated in response to renal injury induced by either ischemia/reperfusion or mercuric chloride. Increased expression of HB-EGF mRNA was demonstrated in the post-ischemic kidney within 45 min of unilateral ischemia/reperfusion in the rat. Induction of HB-EGF mRNA occurred only when ischemia was followed by reperfusion, and was not eliminated by removal of blood cells from the post-ischemic kidney by saline perfusion. In situ hybridization with 35S-labeled antisense riboprobes of HB-EGF indicated that compared with control, there was increased HB-EGF mRNA expression in the 6 h post-ischemic kidney in the inner cortex and outer medulla in a patchy distribution, with the greatest expression in the inner stripe of the outer medulla. Expression occurred primarily in tubular epithelial cells. Recombinant human HB-EGF stimulated [3H]-thymidine incorporation in both primary cultures of rabbit proximal tubule cells and NRK 52E normal rat kidney epithelial cells, with potency similar to that of EGF. Induction of HB-EGF mRNA was observed in tubules freshly isolated from rat renal cortex or outer medulla when the tubules were subjected to reoxygenation after incubation in anoxic conditions. The nephrotoxin, mercuric chloride, also caused induction of HB-EGF mRNA both in vivo and in isolated rat cortical tubules. The anoxia/reoxygenation-induced expression of HB-EGF mRNA in isolated tubules was inhibited by the free radical scavengers, di- and tetra-methylthiourea, indicating involvement of reactive oxygen species. These findings indicate that HB-EGF mRNA is inducible in the kidney in vivo by acute tubular injury and suggest that HB-EGF may act as an autocrine/paracrine growth factor involved in proliferation of tubular epithelial cells and repair of the kidney.

Animals↗
PubMed1995

Transmission of dystrophinopathy by X-chromosome inversion.

A woman had a karyotype of 46Xinv(X)(p21.2;q26.1) and mosaicism of dystrophin-negative muscle fibers. The X-chromosome inversion was transmitted to her daughter, who had an elevated serum CK. The genetic transmission as well as the probable random inactivation of the abnormal X chromosome in this mildly affected patient distinguish this case from those of dystrophinopathy with X;autosome translocations.

Chromosome Inversion↗
PubMed1995

Preparation and antitumor activities of beta-(1-->6) branched (1-->3)-beta-D-glucan derivatives.

The formylmethylated and aminoethylated derivatives of schizophyllan (SPG), a beta-(1-->6)-branched (1-->3)-beta-D-glucan from Schizophyllum commune Fries, were prepared through dimethoxyethylated SPG which was synthesized by the reaction of SPG with dimethylchloracetal under an alkaline condition. The degree of the substitution of formylmethyl groups in the formylmethylated derivative of SPG was estimated as approximately 0.19, and the locations of formylmethyl groups in the derivative were predominantly located at O-6 and/or O-4 positions in glucose residues. The molecular weights of these derivatives were similar to that of SPG, and the helical structure of the derivatives did not seem to be different. The antitumor activities of the formylmethylated and aminoethylated derivatives of SPG against subcutaneously implanted sarcoma 180 solid tumor in mice by intraperitoneal (i.p.) administration were increased more effectively than that of SPG at a dose of 10 mg/kg/d for 7 d starting from 7 d after transplantation of sarcoma 180. The activities inducing tumor regressing factor of the formylmethylated and aminoethylated derivatives were 1.5 to 2 times stronger than that of SPG at a dose of 100 mg/kg. Formylmethylated and aminoethylated derivatives of SPG as well as SPG itself retained the potentiating activity for the reticuloendothelial system. The productions of soluble cytotoxic factors secreted from murine macrophages by the administration of the formylmethylated and aminoethylated derivatives of SPG, which were probably superoxide anion and tumor necrosis factor as measured by the potency of the nitro blue tetrazolium reduction and the cytotoxic activity against L929 cells, respectively, appeared to be more efficient than that of SPG.

Animals↗
PubMed1995

[Surgery of aneurysm of the left subclavian artery applying imaged thoracoscopy--a case report].

A 23-year-old male with aneurysm of the left subclabian artery was successfully treated by means of imaged thoracoscopic surgery. The operation was carried out using double-lumen endotracheal anesthesia. Short trocars were inserted through the left intercostal spaces to introduce a flexible video thoracoscope and surgical instruments. After the area around the proximal end of the subclabian artery was exposed, a tape and Nelaton tube were applied in order to interrupt the artery completely. The maneuvors for aneurysm could be accomplished with minimum invasion, and without thoracotomy. The advantages of this thoracoscopic surgery are: less postoperative pain and discomfort, early recovery and short hospital stay, and cosmetic preservation.

Adult↗
PubMed1995

[A successful surgical treatment in a patient with penetrating left ventricular injury].

A 46-year-old man underwent emergency operation for penetrating cardiac injury resulting in cardiac tamponade. Echo cardiogram showed moderate pericardial effusion. At median sternotomy, incision of pericardium resulted in decompression of pericardial cavity with a subsequent fall in central venous pressure and increased blood pressure. Penetrating wound was found 3 mm from the left anterior descending coronary artery on the left ventricule. The wound was closed with direct mattress suture. He was successfully treated and doing well now.

Aged↗
PubMed1995

[An autopsied case of dominantly affecting upper motor neuron with atrophy of the frontal and temporal lobes--with special reference to primary lateral sclerosis].

In this paper, the autopsy findings of a 78-year-old man mimicking primary lateral sclerosis (PLS) are reported. His clinical symptoms were slowly progressive spasticity, pseudobulbar palsy and character change. He died of sepsis 32 months after protracting the disease. The autopsy revealed severe atrophy of the frontal and temporal lobes. The histological findings were severe neuronal loss with gliosis in the precentral gyrus and left temporal lobe tip, loss of Betz cell, prominent demyelination throughout of the corticospinal tract, axonal swelling in the cerebral peduncule, severe degeneration of the amygdala, mild degeneration of the Ammon horn, normal substantia nigra, a few neuronal cells with central chromatolysis in the facial nerve nucleus and very mild neuronal cell loss in the spinal anterior horn. The anterior horn cell only occasionally demonstrated Bunina body by H & E and cystatin-C stainings, as well as, skein-like inclusion by ubiquitin staining. Thus, this is a case of uncommon amyotrophic lateral sclerosis (ALS) dominantly affecting the upper motor neuron including the motor cortex and temporal limbic system. In analysis of nine cases of putative primary lateral sclerosis in the literature, six cases showed loss of Betz cell in the precentral gyrus, and four cases very mild involvement of the lower motor neuron such as central chromatolysis and eosinophilic inclusion body. Degeneration of the limbic system was observed in two cases. We indicated a possible subgroup with concomitant involvement in the motor cortex and temporal lobe in motor neuron disease dominantly affecting the upper motor neuron.

Aged↗
PubMed1995

Breakdown of self-tolerance by intrathymic injection of a T-cell line inducing autoimmune gastritis in mice.

Autoimmune gastritis (AIG) develops spontaneously in BALB/c mice thymectomized 3 days after birth (3d-Tx). We first confirmed our previous observations that CD4+ splenic T cells in AIG mice induced AIG in nu/nu mice, while those in normal mice suppressed the development of the disease. In addition, we found that a quantitative balance between these effector (Te) and suppressor (Ts) T cells determined either onset or prevention of the disease. Peripheralization of Ts seemed to begin around 3 days after birth, since the incidence of AIG in mice that underwent Tx 6 days after birth (6d-Tx) decreased markedly, compared with that of 3d-Tx mice; 12% in the former, while 79% in the latter. Notably, Ts existed in the 6d-Tx mice that escaped AIG. We next examined the target specificity of such Ts using syngeneic parietal cells known as autoantigens and two kinds of T-cell lines established from an AIG mouse; one is gastritis inducible in vivo, termed A-II, while another is not, named AC-II. Intrathymic injection of parietal cells into mice 3 days after birth followed by 6d-Tx completely prevented the development of AIG. In contrast, injection of irradiated A-II, but not AC-II cells resulted in AIG in 67% of the mice. No autoimmune oophoritis (AIO) was induced in female mice, implying that the breakdown of tolerance is organ specific. Taken together, peripheral tolerance for organ-specific autoantigens seems to be maintained by CD4+ Ts responding to Te, which induces the disease.

Animals↗
PubMed1995

[Evaluation of compression radiotherapy in pelvic treatment].

In pelvic irradiation, the volume of irradiated small intestine is one of the major factors responsible for both acute and late gastrointestinal complications. In this study, exclusion of the small intestine from the pelvic radiation field was attempted with lower abdominal wall compression and bladder distention in the prone position. The mobility of intrapelvic and several problems associated with this technique were investigated. In our results, the small intestine was effectively moved outside of the whole pelvic radiation field in all but two patients. Treatment interruption of 2 days was observed in only two patients. With the AP/PA opposing field method the abdominal skin dose near the compression pillow was revealed to be higher and the dose at the isocenter was inhomogeneous; thus, a three- or four-field technique is recommended if abdominal wall compression is used.

Adult↗
PubMed1995

The effect on tinnitus of stapes surgery for otosclerosis.

Among 42 Japanese patients with otosclerosis who underwent stapes surgery, 22 patients including 10 received total stapedectomy, 6 partial stapedectomy and 6 stapedectomy, were investigated on preoperative and postoperative tinnitus by sending questionnaire. The tinnitus was evaluated by "tinnitus score" advocated by the Japan Audiological Society, and the changes of the scores were analyzed according to pre- and postoperative hearing change, type of stapes surgery and pitches of preoperative tinnitus. In these 22 patients, tinnitus score was improved in 68%, unchanged in 27% or worsened in 5%. Tinnitus was completely disappeared in 6 patients or 27.3%. Tinnitus score became more markedly improved in the patients received partial stapedectomy or stapedotomy than those who received total stapedectomy. Tinnitus score was more likely improved in the patients who had a low pitched tinnitus and presumably had no cochlear otosclerosis preoperatively.

Adult↗
PubMed1995

[A case report of Budd-Chiari syndrome treated with radical operation].

We report a case of Budd-Chiari syndrome in which, radical operation was successfully performed. A 60-year-old male was admitted to our hospital for evaluation of liver dysfunction. Caval venography demonstrated caval obstruction with an extensive collateral circulation passing through the azygos veins. At the operation, intraoperative Doppler echography revealed complete obstruction with thrombus of the IVC. We performed endovenectomy and patch dilatation under circulatory assist with femorofemoral bypass. After this procedures, doppler echography demonstrated excellent flow with no residual stenosis. AKBR was immediately recovered from the abnormal states compared with other laboratory data. The patient has been doing well after 3 years postoperatively.

Budd-Chiari Syndrome↗
PubMed1995

[A case of successful operation for chronic aortic dissection (DeBakey 1 type) complicated with cerebral infarction].

We report a successful operation for a patient of chronic aortic dissection complicated with cerebral infarction. A 60-year-old woman has been treated suffering from cerebral infarction for 7 years. She was referred to our hospital for abnormal chest X-ray and complaint of dry cough. The enhanced CT scan and aortogram demonstrated chronic aortic dissection (DeBakey I) extending from ascending aorta to the abdominal aortic bifurcation with occlusion of right common carotid artery and dilated ascending aorta and aortic arch. The onset of aortic dissection seemed to be, from a clinical point of view, coincident with the onset of cerebral infarction seven years ago. The replacement of the ascending aorta and aortic arch with woven Dacron velour graft were performed under hypothermic and selective cerebral perfusion. The postoperative course was uneventful although complicated with transient recurrence nerve palsy and she has been doing well.

Aortic Aneurysm, Thoracic↗
PubMed1995

Regulation of ion transport by endothelins in rat colonic mucosa: effects of an ETA antagonist (FR139317) and an ETB agonist (IRL1620).

Rat colonic mucosa contains ETA and ETB receptors with Kd values for endothelin (ET)-1 of 32 and 11 pM and maximal binding capacities of 277 and 181 fmol/mg protein, respectively. In muscle-stripped rat colon without tonic nerve activity in Ussing chambers, the serosal addition of ET-1, ET-3 and IRL1620 inhibited amiloride-sensitive noncoupled Na+ entry and enhanced diphenylamine-2-carboxylate-sensitive Cl- secretion, producing a sustained decrease and a transient increase in the short-circuit current (Isc) and the transepithelial conductance, respectively. EC50 values of ET-1, ET-3 and IRL1620 and the maximal changes in Isc were 2.0, 10.2 and 10.9 nM and -12.7, -7.0 and -7.1 muA/cm2, respectively for the Na+ entry; these values were 50, 220 and 225 nM and +57.3, +47.3 and +21.3 muA/cm2, respectively, for the Cl- secretion. FR139317 (100 nM) inhibited ET-1-induced Na+ and Cl- movements, shifting the concentration-response curves to the right (EC50 = 25 nM and 1 microM, respectively), and inhibited ET-3 (> 100 nM)-induced Cl- movement, decreasing the maximal response to 35%, but it did not inhibit either ET-3-induced Na+ movement nor IRL1620-induced Na+ and Cl- movements. The removal of serosal Ca++ reduced 100 nM ET-1- and IRL1620-evoked changes in Isc by 50% and 70% for the Na+ entry and by 80% and 100% for the Cl- secretion, respectively. Indomethacin (1 microM) also reduced changes in Isc by 30% and 70% for the Cl- secretion but did not affect the Na+ entry. Our results show that ETA and ETB receptors regulate Na+ and Cl- transport by different mechanisms.

Animals↗
PubMed1995

Endoscopic aspiration lumpectomy of esophageal leiomyomas derived from the muscularis mucosae.

OBJECTIVES: There is still much debate about the indications and best technique for endoscopy for the treatment of esophageal leiomyomas. We developed a novel technique for endoscopic aspiration lumpectomy and used it in patients with esophageal leiomyomas derived from the muscularis mucosae. METHODS: Nine patients with esophageal leiomyomas were treated with informed consent. The indication for intervention was based on the endosonographic confirmation of a tumor originating from the 2nd layer of the esophagus. We attached a transparent cylinder to the tip of an endoscope and a snare-guide tube to the outer axis of the scope. After endoscopic suction of the tumor into the cylinder, the snare was pushed open. The tumor was grabbed at its base with the entire surrounding mucosa, and removed. RESULTS: The overall procedure time averaged 18 minutes, and there were no complications in any of the subjects. The resected specimens were elliptical with a mean long diameter of 22 +/- 4 mm and a mean short diameter of 17 +/- 4 mm. Complete resection was possible in eight of the nine tumors that were under 2 cm in diameter. After a follow-up period of 4 to 27 months (mean 11 months), no recurrence was found in any of the completely resected cases. CONCLUSIONS: Endoscopic aspiration lumpectomy has been proven to be a safe, effective, and less invasive procedure for small esophageal leiomyomas derived from the muscularis mucosae.

Esophageal Neoplasms↗
PubMed1995

[A case of successful redo-operation for active prosthetic valve endocarditis after modified Bentall operation].

A redo-operation for active prosthetic valve endocarditis after modified Bentall operation is reported. A 42-year-old man associated with Marfan syndrome was transferred to our hospital with complaints of high fever and general fatigue. A modified Bentall operation for acute aortic dissection was done five years ago. The aortic arch and descending thoracic aorta were replaced with prosthetic graft because of aneurysmal dilatation four years ago. Transesophagial echogram revealed a developing vegetation below the prosthetic valve and at the left ventricular outflow. A redo-operation of translocation method with Pieler method for coronary reconstruction was performed using a prosthetic valve of SJM 21 mm in size. After operation, hemolysis suddenly appeared and hepatic dysfunction gradually progressed. Reoperation was necessary for the redo-operation and and a SJM 21 mm valve was replaced with a new 25 mm SJM valve interposed between the graft. Hemolysis was immediately improved. A redo operation of translocation method with Pieler method for coronary reconstruction showed a good results.

Adult↗
PubMed1995

[Long-term results of surgical treatment for renal pelvic and ureteral tumors].

Fifty eight cases of primary tumors in the renal pelvis and ureter were treated at Toranomon Hospital between 1983 and 1992. They consisted of 32 renal pelvic tumors, 21 ureteral tumors and 5 tumors at both sites. The age of the patients ranged from 30 to 84 years (mean 63.1). Surgery was performed in 56 cases. Radical nephroureterectomy with concomitant ipsilateral retroperitoneal lymph node dissection was performed in 38 cases. The other surgeries were radical nephroureterectomy without lymph node dissection in 9, nephrectomy in 4, resection of ureter and reanastomosis in 3, radical nephroureterectomy and cystectomy in 1 and partial nephrectomy in 1. Pathologically, 53 were transitional cell carcinoma (TCC), 2 were TCC plus squamous cell carcinoma and 1 was TCC plus adenocarcinoma. Over-all survival rates (Kaplan-Meier) of 56 surgical cases at 1, 3, 5 years were 92.2, 83.7 and 72.8%, respectively. Combination chemotherapy (M-VAC or CAP) was performed in 9 cases of metastatic disease and 1 case of bilateral disease. Of these 10 cases, one achieved complete remission, 2 no change and 7 had progressive disease. Adjuvant chemotherapy was performed in 21 cases after surgery. These 21 patients were of high risk in recurrence either Grade 3 or pT3. However, the 5-year survival rate was 77.3% in these patients. Thus we conclude that the adjuvant chemotherapy in high risk patients was effective in our cases.

Adult↗