Biomedical subjects

S Kitano

Publications and source records attributed to S Kitano.

At least 109 records · Page 6Linked to original sources

PubMed1998

Identification and cloning of human G-protein gamma 7, down-regulated in pancreatic cancer.

Differentially expressed genes between normal and cancer tissues of the pancreas were investigated using differential display. Consequently, we identified a fragment cDNA that was expressed in the normal tissue but was rarely expressed in the cancer tissue. This cDNA was screened in cDNA library prepared from the normal pancreatic tissue by rapid amplification of cDNA ends (5'RACE). 859 bp of cDNA was cloned and sequenced, and the inferred amino acid sequence was found to encode a G protein gamma subunit with 98% homology to cow G protein gamma 7 and complete homology to human G protein gamma 7. The decreased expression of the G protein gamma 7 was confirmed by Northern blot assay in twelve pancreatic malignancies which included nine duct cell carcinomas, two cystoadenocarcinomas and one blastoma. Reverse transcriptase (RT)-polymerase chain reaction (PCR) assay showed no expression of G protein gamma 7 in five of six pancreatic carcinoma cell lines and two pancreatic cancer tissues. Immunohistochemical analysis also displayed positive staining in the normal tissue but no staining in the cancer tissue. The findings demonstrated that the reduced or suppressed expression of human G-protein gamma 7 may play an important role in pancreatic carcinogenesis.

Amino Acid Sequence↗

PubMed1998

Paget's Disease of the Breast: Report of Five Cases and Review of the Japanese Literature.

Five cases of Paget's disease of the breast are presented, and 76 cases reported in the Japanese literature are analyzed. Paget's disease of the breast is often confined to the nipple-areolar complex(68%), and the duration of symptoms issometimes more than 5 years(25%). Paget's disease without palpable tumor in theunderlying breast is characterized by a low incidence of invasive ductal carcinoma(8%), lymph node metastasis(8%), and stage II or greater disease(0%). These cases indicate that Paget's disease without palpable breast tumor has less aggressive behavior and more benign course than that with palpable breast tumor, and local excision and/or radiation therapy may be an alternative to mastectomy as the initial treatment.

Journal Article↗

PubMed1998

Sphingomyelinase and ceramide inhibit formation of F-actin ring in and bone resorption by rabbit mature osteoclasts.

Recent studies have demonstrated that ceramide plays an important role as a second messenger in many kinds of cells. However, it is not known whether apoptosis of and bone resorption by mature osteoclasts are mediated via sphingomyelinase (SMase) and ceramide. Thus, we examined the possible involvement of SMase and ceramide in the induction of apoptosis in and bone resorption by rabbit mature osteoclasts. SMase and C2-ceramide inhibited strongly F-actin ring formation of and bone resorption by the osteoclasts. However, the osteoclast apoptosis was not induced by C2-ceramide. The ceramide inhibition of the bone resorption was suppressed by DL-threodihydrosphingosine, an inhibitor of sphingosine kinase. In addition, we observed that sphingosine-1-phosphate is able to inhibit bone resorption by the osteoclasts. These results suggest an important role of the sphingomyelin pathway in bone resorption by rabbit mature osteoclasts.

Actins↗

PubMed1998

Effect of aging on EGF-stimulated replication of specific genes in rat hepatocytes.

EGF-stimulated replication of specific genes was examined in primary hepatocyte cultures from mature (6 months) and senescent (24 months) rats. Basal and EGF-stimulated [3H]thymidine incorporation and DNA polymerase alpha activities, as well as total cellular DNA, were also assessed. The genes examined were dihydrofolate reductase (DHFR) and c-myc, as well as total mitochondrial DNA (mt DNA). Although [3H]thymidine incorporation, DNA polymerase alpha activity, total cellular DNA, DHFR, and c-myc gene specific DNA replication stimulated by EGF are reduced with age, mt DNA replication is not affected by either EGF or age. Chromosomal DNA replication is mediated mainly by DNA polymerase alpha while mt DNA replication is mediated by its own DNA polymerase gamma. Thus, the age-related decline in stimulated DNA replication appears to be associated mainly with the DNA polymerase alpha activation pathway.

Aging↗

PubMed1998

Vasopressin antagonist improves renal function in a rat model of pneumoperitoneum.

Pneumoperitoneum (PP) is associated with oliguria and increased plasma arginine vasopressin (AVP) levels. This study investigated the role of AVP in the pathogenesis of oliguria due to PP. Anesthetized and ventilated rats (n = 12) were subjected for 1 h to carbon dioxide PP with an intra-abdominal pressure of 8 mmHg or, as control, at 0 mmHg, before the determination of plasma AVP level. Another group of rats (n = 48) subjected to PP or control conditions was pretreated with the AVP V2 receptor antagonist, OPC-31260 (5 mg/kg), or vehicle, and their renal parameters were measured. Glomerular filtration rate (GFR) was determined by inulin clearance in an additional group of rats (n = 12) subjected to PP with or without pretreatment with OPC-31260. Rats subjected to PP had higher plasma AVP levels than did controls (17.3 +/- 8.1 pg/ml vs 1.5 +/- 0. 6 pg/ml, P < 0.05). In rats pretreated with vehicle, PP decreased urine output, excretion of water, and urea nitrogen, leading to reduced serum osmolality and serum sodium levels as well as elevated blood urea nitrogen levels. OPC-31260 pretreatment improved urine output, excretion of water, and urea nitrogen, thereby preventing changes in serum osmolality, serum sodium levels, and blood urea nitrogen levels. OPC-31260 pretreatment did not affect GFR. Results suggest that plasma AVP contributes to the oliguria due to PP. OPC-31260 may be useful in treating the water retention associated with PP.

Animals↗

PubMed1998

Clinical significance of ventricular size in shunted-hydrocephalic children.

For maintaining the intracranial buffering capacity against shunt obstruction, we tried to seek the most suitable size of the lateral ventricles in hydrocephalic children. Thirty-seven shunted-hydrocephalic children who required emergent revision of the shunt were analyzed. At the time of shunt obstruction, the lateral ventricle remained small (0.35 or less than 0.35 on the Evans' index) in 13 patients (Slit-like group), but it enlarged (more than 0.35 on the Evans' index) in 24 patients (Dilated group). The mean age in the Slit-like group was significantly older than in the Dilated group and there was no patient younger than 3 years in the Slit-like group. Compared with the Dilated group, the Slit-like group showed significantly rapid deterioration into lethargy after shunt obstruction. Also, at the time of obstruction CT scans showed a significantly higher rate of narrowing of the ambient cistern. While the shunt was working well before shunt obstruction, the Evans' index was less than 0.33 in all patients of the Slit-like group. In conclusion, because small ventricles after shunt strongly suggest the presence of ventricular tautness, the lateral ventricular size should be maintained at more than 0.33 on the Evans' index in shunted children at an age of 3 or more than 3 years.

Adolescent↗

PubMed1998

Bone mineral density in patients taking H2-receptor antagonist.

Osteoporosis after gastrectomy is a common clinical disorder. In gastrectomized patients, decreased gastric acidity may be associated with impaired calcium absorption. This study was undertaken to determine whether patients with chronic use of H2-receptor antagonists (HRA) had demonstrable decreases in bone mineral density (BMD). Thirty-three patients taking cimetidine, ranitidine, or famotidine for more than 2 years were analyzed. We measured BMD of L2-L4 using dual energy X-ray absorptiometry (DXA). Osteoporosis (BMD less than 0.70 g/cm2) was found only in three patients (9%). As compared with healthy controls, age- and sex-matched BMD ranged from 74.4% to 132.9%, with a mean of 97.0%, and was not influenced by the period of HRA use (<5 years versus >5 years or more). Although the age- and sex-matched BMD was different among the kinds of HRA (98.6% for cimetidine, 101.3% for ranitidine, and 85.5% for famotidine), the relationship between the BMD and type of drug was not significant by multivariate analysis. These results indicate that chronic use of HRA has little influence on the degree of BMD, and suggest that decreased gastric acidity is not always associated with osteoporosis after gastrectomy.

Adult↗

PubMed1998

Comparison of pneumoperitoneum and abdominal wall lifting as to hemodynamics and surgical stress response during laparoscopic cholecystectomy.

BACKGROUND: Impairments in hemodynamics during pneumoperitoneum (PP) have been noted. This study compared changes in hemodynamics and surgical stress response with PP and abdominal wall lifting (AWL) during laparoscopic cholecystectomy. METHODS: Twenty patients with symptomatic cholecystolithiasis were assigned to PP (n = 10) or AWL (n = 10). Cardiac output (CO), stroke volume (SV), and ejection fraction (%EF) were measured by transesophageal echocardiography. Clearances of para-aminohippurate (CPAH) and sodium thiosulfate (CSTS) were determined as measures of renal function. Levels of interleukin-6, C-reactive protein, white cell count, and neutrophil elastase were evaluated as indicators of surgical stress. RESULTS: In the PP group, CO, SV, and %EF were depressed significantly during pneumoperitoneum. Immediately after and 15 min after insufflation, the CPAH and CSTS were decreased by 78.0% and 73.8%, respectively. None of the hemodynamic parameters changed significantly in the AWL group. Surgical stress response was not different significantly between the two groups. CONCLUSIONS: In contrast to pneumoperitoneum, AWL did not alter cardiac function or renal hemodynamics. AWL may be useful in patients with cardiovascular or renal disorders.

Abdominal Muscles↗

PubMed1998

Laparoscopic cholecystectomy in patients undergoing anticoagulant therapy.

We recently performed a laparoscopic cholecystectomy on three patients receiving preoperative oral anticoagulant therapy. The patients requiring anticoagulants for pre-existing cardiac conditions have the following risks at surgery: thromboembolism, hemorrhage, endocarditis, and cardiopulmonary dysfunction. In patients receiving anticoagulant therapy, one must thus maintain a balanced international normalized ratio of the prothrombin time to prevent thromboembolism or hemorrhage. Warfarin sodium was discontinued preoperatively in all patients. Heparin sodium was individualized according to each patient's risk of thromboembolism. As a result, these patients all underwent a laparoscopic cholecystectomy without complications. Attention was paid to achieve hemostasis in the operative field and the trocar inserted sites during the procedure. The administration of warfarin sodium was resumed on the first postoperative day in all patients. Restarting warfarin sodium early also helps to simplify postoperative management. A broad spectrum of antibiotic therapy was also used to reduce the risk of endocarditis. Each patient's cardiopulmonary function was carefully monitored. The minimal invasion experienced during a laparoscopic cholecystectomy may thus facilitate the management of gallstones in patients receiving systemic anticoagulation treatment based on the findings of this limited series.

Adult↗

PubMed1998

Laparoscopic enucleation of a pancreatic insulinoma: report of a case.

We report herein the case of a 48-year-old Japanese woman in whom a pancreatic insulinoma was successfully treated by laparoscopic enucleation. The patient presented after developing episodic neurohypoglycemic symptoms, and an insulinoma in the pancreatic tail, 1.0 cm in diameter, was diagnosed by the results of biochemical and radiological examinations. A laparoscopic intraoperative ultrasonogram demonstrated a solitary hypoechogenic tumor in the pancreatic tail. After the tail and body of the pancreas with the spleen were mobilized, laparoscopic enucleation was performed without any complications. The total operative time was 225min and the estimated blood loss was 20 ml. Serial blood sugar measurements demonstrated a sharp rise in blood sugar levels at the time of enucleation. The patient's postoperative course was uneventful, and she was discharged on the seventh postoperative day. She has remained well for 33 months following surgery without any hypoglycemic symptoms.

Female↗

PubMed1998

An additional variant of the persistent primitive trigeminal artery: accessory meningeal artery--antero-superior cerebellar artery anastomosis associated with moyamoya disease.

Persistent embryological carotid-basilar anastomoses are rare. There has been no report on persistent anastomosis between the accessory meningeal artery and the antero-superior cerebellar artery. We describe a 3-year-old boy with moyamoya disease manifesting such a congenital vascular anomaly, namely, a large anastomosis between the accessory meningeal artery and the antero-superior cerebellar artery associated with marked hypoplasia of the basilar artery. This persistent vascular anomaly is considered embryologically as an additional variant of the persistent primitive trigeminal artery, i.e., a "stapedo-trigemino-cerebellar" variant.

Basilar Artery↗

PubMed1998

Laparoscopic splenopexy for pediatric wandering spleen.

Wandering spleen is an uncommon condition, showing a splenic hypermobility that results from laxity or maldevelopment of its suspensory ligament. This condition results in constant danger of splenic torsion and infarction. Wandering spleen was diagnosed in a 2-year-old girl who complained of intermittent abdominal pain, and viability of the spleen was confirmed by doppler ultrasound scan. Elective laparoscopic splenopexy was performed by anchoring the spleen wrapped in absorbable mesh. To our knowledge, this is the first reported case of laparoscopic splenopexy for wandering spleen. The authors believe that this approach is a safe and effective procedure for wandering spleen with the advantage of minimally invasive surgery.

Child, Preschool↗

PubMed1998

Decreased circulating levels of vitamin K and 25-hydroxyvitamin D in osteopenic elderly men.

Changes in the circulating factors participating in involutional osteoporosis have been intensively investigated in women, but little is known about this in men. We investigated the possible participation of circulating factors including testosterone, vitamin D metabolites, and vitamins K1 and K2 in osteopenia in elderly men. In a group of 27 ambulatory men aged 74 +/- 10 years (mean +/- SD; range, 60 to 90), the bone mineral density (BMD) of the second to fourth lumbar vertebrae was measured by dual-energy x-ray absorptiometry (DXA) and expressed as a Z score, the age-adjusted BMD value for the Japanese population (mean +/- SD, 0 +/- 1). Although the plasma level of total testosterone significantly decreased with age in the group, it did not significantly correlate with the Z score. However, the plasma levels of 25-hydroxyvitamin D (25-OHD), phylloquinone, menaquinone-7 (MK-7), and albumin were significantly positively correlated with the Z score. Moreover, plasma 25-OHD and both phylloquinone and MK-7 were significantly positively correlated in the subjects. These observations suggest that depressed circulating levels of 25-OHD and vitamin K concomitantly and cooperatively participate in osteopenia in elderly men, which may reflect the etiology of the type II moiety of involutional osteoporosis.

Aged↗

PubMed1998

A transient increase in endogeneous erythropoietin levels after paediatric liver transplantation.

We investigated whether liver transplantation affects endogeneous erythropoietin (EPO) synthesis. Serum EPO levels were measured before transplantation and during the peri-transplant period in ten consecutive paediatric patients who had received a liver allograft without recombinant EPO therapy. All patients were anaemic on post-operative day 1 (POD 1); however, the haemoglobin levels of three patients gradually increased and required phlebotomy on POD 5-9. The serum levels of EPO in all patients were within the normal range before surgery, but six of the ten patients had a transient increased level of EPO at 1248 h after transplantation. A transient increase of endogeneous EPO following paediatric liver transplantation may be associated with extramedullary erythropoiesis in human liver grafts.

Child↗

PubMed1998

Relation between tumour necrosis factor alpha and interleukin 1beta producing capacity of peripheral monocytes and pulmonary complications following oesophagectomy.

BACKGROUND: Adult respiratory distress syndrome and pneumonia remain a significant cause of morbidity and death following oesophagectomy. The aim of this study was to clarify the association between tumour necrosis factor (TNF) alpha and interleukin (IL) 1beta with these pulmonary complications. METHODS: The in vitro TNF-alpha and IL-1beta producing capacity of peripheral monocytes with or without lipopolysaccaride (LPS) and serum level of IL-6 was measured in 19 patients with oesophageal cancer before and after surgery and in ten age-matched controls. RESULTS: Six patients had raised TNF-alpha and IL-1beta producing capacity of monocytes without LPS both before operation and on the day after surgery. In these patients plasma elastase and serum IL-6 levels subsequently increased while the ratio of arterial partial pressure of oxygen to fraction inspired oxygen decreased, and they developed bilateral lung infiltration on chest radiography on days 3-7. Five of the six developed pneumonia compared with none of the remaining 13 patients (P < 0.05). CONCLUSION: Pulmonary impairment and pneumonia following oesophageal surgery was associated with raised monocyte producing capacity of TNF-alpha and IL-1beta. These markers may be valuable in the preoperative assessment of patients awaiting oesophagectomy.

Aged↗

PubMed1998

Intrahepatic peripheral cholangiocarcinoma: mode of spread and choice of surgical treatment.

BACKGROUND: Classification of macroscopic appearance and standard operative procedures for intrahepatic cholangiocarcinoma (ICC) are still controversial. METHODS: The mode of spread of 12 resected ICCs was examined by light microscopy, and the appropriate operative procedures for the various tumours were considered. RESULTS: Macroscopically, nine tumours were classified as mass-forming type and three as periductal infiltrating type. All patients were treated by major hepatectomy; resection of the extrahepatic bile duct was included in two cases of the periductal infiltrating type. Microscopically, invasion into the portal vein, intrahepatic metastasis and perineural or lymphatic vessel invasion occurred in none, one and all of three tumours of the periductal infiltrating type and in eight, six and six of nine tumours of the mass-forming type. CONCLUSION: ICC of the periductal infiltrating type has a tendency to spread along Glisson's sheath via lymphatic vessels. By contrast, ICC of the mass-forming type tends to invade the liver via the portal vein system; such tumours begin to invade Glisson's sheath through the lymphatic vessels when the tumour has increased in size. Therefore, major hepatectomy with combined resection of the extrahepatic bile duct should be performed for all ICCs of the periductal infiltrating type and for those of the mass-forming type with invasion of Glisson's sheath.

Adult↗

PubMed1998

Perigastric lymph node status as a prognostic indicator in patients with gastric cancer.

BACKGROUND: The extent of lymph node dissection and histological examination of dissected lymph nodes varies among countries, which leads to the erroneous nodal stage and different surgical results in gastric cancer (stage migration, 'Will Rogers effect'). The aim of this study was to clarify the prognostic significance of the number of positive perigastric lymph nodes, which could be evaluated simply after D1 gastrectomy. METHODS: A consecutive series of 106 patients with histologically node-positive gastric cancer treated by radical gastrectomy and lymph node dissection (D2 or D3) was studied. The number of metastatic perigastric nodes (level I, nos 1-6) was examined, and its influence on the survival of patients was analysed. RESULTS: The overall 5-year survival rate was 50.9 per cent; the 5-year survival rate was significantly decreased when positive perigastric nodes exceeded six (62 per cent for one to six nodes versus 23 per cent for seven or more nodes, P< 0.001). Tumours having one to six positive perigastric nodes compared with those having seven or more positive perigastric nodes were more likely to have a size less than 4 cm (29 per cent versus one of 30, P< 0.001), grossly localized type (45 per cent versus seven of 30, P=0.042), absence of serosal invasion (32 per cent versus none of 30, P=0.002) and metastasis limited to the perigastric lymph nodes (70 per cent versus seven of 30, P < 0.001). CONCLUSION: The results indicate that the number of positive perigastric nodes correlates with tumour progression and patient survival. This parameter is a simple and useful prognostic indicator for node-positive gastric cancer, and is available not only for D2 and D3 gastrectomy but also for D1 gastrectomy.

Adult↗

PubMed1998

Inhibition of mitochondrial gene expression by antisense RNA of mitochondrial transcription factor A (mtTFA).

Mitochondrial transcription factor A (mtTFA) plays an important role in regulating the expression of mitochondrial genes. To gain a better understanding of the relationships between mitochondrial gene expression and mtTFA, the mtTFA gene was inserted into a mammalian expression vector, both in the sense orientation and in the antisense orientation. After construction, these plasmids were transfected into COS-7 cells. In antisense-transformed cells, the expression of the cytochrome c oxidase subunit I and subunit III genes encoded by mitochondrial DNA was inhibited and there was an accompanying reduction of the level of mtTFA protein. These results provide direct evidence that the expression of mitochondrial genes is under the control of mtTFA.

Animals↗