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Biomedical subjects

H Imamura

Publications and source records attributed to H Imamura.

482 records · Page 27Linked to original sources

Small cystic insulinoma: value of arterial stimulation venous sampling.

Cystic insulinomas are rare, with only three cases having been reported in the literature. It is not difficult to determine the site of such neoplasms, as cystic insulinomas are usually 4-10 cm in diameter. We report a patient with a histologically confirmed cystic insulinoma. This case is unique because of the small size (1.3 cm) of the tumor. Arterial stimulation venous sampling was useful for localizing and distinguishing this tumor from other pancreatic lesions.

Calcium Gluconate↗

Effects of the Na+/H+ exchange inhibitor cariporide (HOE 642) on cardiac function and cardiomyocyte cell death in rat ischaemic-reperfused heart.

1. Na+/H+ exchange has been implicated in the mechanism of reperfusion injury. We examined the effects of the cardiac-specific Na+/H+ exchange inhibitor cariporide (HOE 642) on postischaemic recovery of cardiac function and cardiomyocyte cell death (i.e. necrosis and apoptosis). 2. Rat isolated and buffer-perfused hearts were subjected to 25 min normothermic global ischaemia followed by 120 min reperfusion. Cariporide (10 micromol/L) or its vehicle (0.01% dimethylsulphoxide) was administered for 15 min before ischaemia and for the first 30 min after reperfusion. 3. Cariporide significantly improved the recovery of isovolumic left ventricular function (heart rate, left ventricular developed pressure and left ventricular end-diastolic pressure) and coronary flow throughout reperfusion. Creatine kinase release during reperfusion was significantly less in the cariporide-treated heart. In situ terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL)-positive cardiomyocytes were also significantly less in the cariporide-treated heart after 120 min reperfusion. Electron microscopy showed necrotic changes without typical apoptotic features in cardiomyocytes after reperfusion. Such necrotic changes were mitigated by cariporide. Simultaneous detection of necrotic and apoptotic cardiomyocytes using propidium iodide (PI) and Annexin V revealed that cardiomyocytes in the infarct area were stained with only PI or both PI and Annexin V. Cariporide did not alter the pattern of cardiomyocyte staining with PI and Annexin V, although the number of cardiomyocytes stained with PI or PI plus Annexin V was less than that in vehicle-treated hearts. 4. These results suggest that apoptosis is not a major manifestation of cardiomyocyte cell death in the ischaemic-reperfused myocardium and a cariporide-sensitive mechanism of reperfusion injury promotes both necrotic and apoptotic processes of cell death.

Animals↗

Relationship of cigarette smoking with blood pressure, serum lipids and lipoproteins in young Japanese women.

1. The relationship of cigarette smoking with blood pressure and serum lipids and lipoproteins was studied in 1062 young Japanese women aged 20-39 years of age. 2. After adjusting for age, body mass index (BMI), alcohol intake and physical activity scores, the mean systolic and diastolic blood pressures (SBP and DBP, respectively) did not indicate dose-dependent relationships with cigarette smoking. The largest significant mean differences in SBP (3.5%; P < 0.001), DBP (6.2%; P < 0.018), high-density lipoprotein-cholesterol (HDL-C; 13.2%; P < 0.005), ratio of total cholesterol to HDL-C (13.9%; P < 0.022), triglycerides (TG; 24.1%; P < 0.001) and the logarithmic transformation of TG (log TG; 5.6%; P < 0.001) were found between non-smokers and smokers. 3. When age, BMI, alcohol intake and physical activity scores were included in the forward step-wise multiple regression analysis, there were negative relationships found for cigarette smoking and SBP and DBP and positive relationships for cigarette smoking and TG and log TG. 4. Although the results are somewhat variable, the present study shows that cigarette smoking is negatively associated with SBP and DBP and that there is an association between cigarette smoking and serum lipids and lipoproteins and that smoking has an unfavourable effect on these parameters in young Japanese women.

Adult↗

Liver regeneration after extended right hemihepatectomy in patients with hilar or diffuse bile duct carcinoma.

BACKGROUND/AIMS: The degree to which liver size can be restored and the factors that determine liver regeneration after major hepatectomy are not well understood. METHODOLOGY: Liver volumes (LV) were estimated from computed tomography scans in 16 patients who survived with no evidence of cancer recurrence more than 1 year after extended right hemihepatectomy. RESULTS: The mean percentage of LV at 1 year was 75.7 +/- 9.5% and LV did not change significantly beyond 1 year after surgery. A significant correlation was observed between LV at 1 year and body surface area (r = 0.79, p < 0.001). A significant inverse correlation was observed between LV at 1 year and the plasma retention rate of indocyanine green at 15 min (the ICG 15 value) (r = -0.72, p < 0.01). CONCLUSIONS: In adults, the liver does not always regain its pre-operative size after hepatectomy. Patients' body size and intrinsic liver function or liver blood flow, represented by the ICG 15 value, may be related to regenerated liver size.

Aged↗

Antitumor efficacy of combination chemotherapy with UFT and cyclophosphamide against human breast cancer xenografts in nude mice.

The combination of cyclophosphamide (CPA) and 5-fluorouracil (5-FU) is currently regarded as the most effective therapy for the treatment of patients with advanced and recurrent breast cancer. We evaluated the augmentation of antitumor activity and toxicity by coadministration of CPA and UFT (1M tegafur--4M uracil) instead of intravenous 5-FU on H-31 human breast cancer xenografts in nude mice. The maximum tolerable dose (MTD) of UFT alone (24 mg/kg) and CPA alone (85 mg/kg) had a significant effect on H-31 tumors in mice with 86.6% and 83.0% inhibition rates of tumor growth, respectively, and without loss of body weight, diarrhea or myelosuppression. The combined administration with full and 83.3% MTD of UFT and CPA augmented the antitumor activity compared to that of UFT alone and CPA alone. The relative tumor volume of the UFT plus CPA-treated group to the UFT- and CPA-treated groups was 0.28 and 0.36 for the full MTD, and 0.51 and 0.67 for 83.3% MTD, respectively. When CPA was consecutively administered to the tumor-bearing mice for 14 days, there were no decreases in the activities of enzymes related to 5-FU metabolism, but there was an significant increase in the activity of ribonucleotide reductase, suggesting that anabolism of 5-FU derived from tegafur is accelerated to some extent by coadministration of CPA. In conclusion, these results suggest that combination therapy with oral UFT and CPA may be useful for the long-term treatment of cancer patients with advanced and recurrent breast cancers.

Animals↗

Technical dilemma in living-donor or split-liver transplant.

In partial liver transplantation for adults criteria for the extent of reconstruction of middle hepatic vein tributaries have not been clarified. After hepatic venous and portal anastomoses in living-donor liver transplantation using left liver graft without middle hepatic vein, color Doppler ultrasonography was applied to check venous and portal blood flow. Color Doppler ultrasonography demonstrated absent hepatic venous flow and reversed portal venous flow in the congested area of the left paramedian sector which had been drained by the divided branch of the middle hepatic vein. The area was darkly discolored before arterial reperfusion and under clamping of the artery. Reconstruction of the venous branch was added after arterial anastomosis. Color Doppler ultrasonography revealed restored normal venous outflow and portal inflow after venous reconstruction. Postoperative course of the recipient was uneventful with rapid recovery of liver function. We propose that middle hepatic vein tributaries should be reconstructed if color Doppler ultrasonography demonstrates absent venous flow and reversed portal flow, and if the liver volume excluding the discolored area under occlusion of the hepatic artery is estimated to be insufficient for postoperative metabolic demand.

Anastomosis, Surgical↗

Liver transplantation using a right lateral sector graft from a living donor to her granddaughter.

One of the major concerns regarding living-related liver transplantation is graft-size disparity. The left liver graft is too small while the right is too large in some recipients. To overcome this problem, the right lateral sector (Segments VI and VII) was transplanted from a living donor (55 kg) to her granddaughter (17 kg). The common hepatic trunk had to be anastomosed end-to-end to the graft hepatic vein without being compressed by the graft overriding the vena cava and without unfavorable tension of the anastomosis. The anterior wall of the hepatic vein of the donor was resected as much as possible. The superficial left, left, middle and right hepatic veins of the recipient were made confluent by incision of the intervening venous walls, and the nicks were sutured to form a wide and long common venous trunk. The recipient received a graft corresponding to 75% of her standard liver volume. She was complicated with gastric dilation and acute rejection, but recovered with no signs of anastomotic stricture. Right lateral sector graft obtained by this innovative procedure may be useful for overcoming borderline graft-recipient size and shape differences.

Age Factors↗

Effect of dietary treatment on the renal tubular function in a patient with hereditary tyrosinemia.

In a 1 1/2-month-old girl with hereditary tyrosinemia, renal tubular function studies were done. The effect of a low tyrosine and phenylalanine formula on renal tubular functions was also studied. The tubular handling of phosphorus, uric acid, beta 2-microglobulin, and amino acids was disturbed. Low urinary osmolality was also seen. Creatinine clearance was increased during a period of the standard formula. Although treatment with the low tyrosine and phenylalanine diet produces dramatic improvement in plasma tyrosine and tyrosyluria, all tubular symptoms did not revert to normal. It is possible that tubular dysfunction of hereditary tyrosinemia may be irreversible changes.

Amino Acid Metabolism, Inborn Errors↗

Distal and proximal dissection of an abdominal aortic aneurysm.

A case of abdominal aortic aneurysm in which dissection developed in retrograde fashion into the thoracic aorta is reported. The aortogram showed findings similar to DeBakey Type-IIIb dissection. No intimal tear was seen in the thoracic aorta; however, the origin of the intimal tear was found in the abdominal aorta. Renal hypertension also developed due to distal dissection of the right renal artery. Closure of the primary intimal tear, partial closure of the false channel and removal of the right kidney were performed therefore, reattachment of vessels was not required. This was the first case in which a primary tear was seen in the abdominal aorta in our 37 surgical cases of dissecting aortic aneurysm. Three cases of retrograde dissection of abdominal aortic aneurysm have been reported in the English literature as far as we have determined. The importance of accurate detection of the origin of the intimal tear is emphasized.

Aortic Dissection↗

Coronary perfusion under general and selective cardiac hypothermia.

Experiments to assess left ventricular function in dogs during and after 2 hours of hypothermic cardioplegia are reported. During the experiment myocardial temperature was maintained between 15 degrees C and 18 degrees C by controlling the rate of flow of a cool cardioplegic solution into the coronary vessels. Before and after the period of hypothermia the left atrial pressure was gradually changed and the aortic flows and pressures that changed in response were recorded. The left ventricular stroke work (gm) was then calculated using the relationship: LVSM = (formula: see text) where: SV = stroke volume (ml), AP = arterial pressure (mmHg), LAP = left atrial pressure (mmHg). Comparison of the calculated values indicated that this method of maintaining cardiac hypothermia reduced cardiac function only slightly.

Animals↗