Biomedical subjects

H Watanabe

Publications and source records attributed to H Watanabe.

At least 559 records · Page 31Linked to original sources

PubMed1999

Generation of new transposons in vivo: an evolutionary role for the "staggered" head-to-head dimer and one-ended transposition.

From a plasmid carrying the tnpA gene and one inverted repeat sequence (IR) of transposon Tn3, plasmids containing a structure characteristic of transposons, i.e., two IRs flanking a tnpA gene, were generated spontaneously in vivo. They appear to have arisen either through the formation of a "staggered" head-to-head dimer or by so-called one-ended transposition. These putative transposons could indeed transpose to, or form cointegrates with, a recipient plasmid. Based on these findings it is proposed that a primeval transposase gene and its target site evolved first, and subsequently gave rise to a "fully-fledged" transposon by head-to-head dimerization or one-ended transposition.

Base Sequence↗

PubMed1999

Reduced prevalence of diabetes according to 1997 American Diabetes Association criteria.

AIMS/HYPOTHESIS: We examined the prevalence of diabetes and investigated the characteristics of subjects diagnosed by the American Diabetes Association and the World Health Organization criteria. METHODS: A total of 1235 Japanese-Americans living in Hawaii and Los Angeles was studied. Of the subjects 114 were classified as previously diagnosed as having diabetes. A 75-g glucose tolerance test was given to the rest of the subjects. RESULTS: When abnormal glucose tolerance was diagnosed by the American Diabetes Association criteria, it was possible to identify only 40 % of diabetic subjects who had not been previously diagnosed compared with the current World Health Organization criteria based on a glucose tolerance test. In addition, the subjects identified by the American Diabetes Association criteria had higher glucose concentrations and had less insulin secretory capacity and they were in need of intensive treatment for diabetes. On the other hand, the subjects not diagnosed by the American Diabetes Association criteria alone were those whose glucose tolerance would be more likely to improve with lifestyle modification. CONCLUSION/INTERPRETATION: It might be better to use the fasting plasma glucose criterion advocated by the American Diabetes Association in combination with a glucose tolerance test after taking a detailed medical history. To reduce the number of subjects requiring the glucose tolerance test, priority should be given to subjects with impaired fasting glucose (6.1 </= fasting plasma glucose < 7.0 mmol/l). [Diabetologia (1999) 42: 1168-1170]

Adult↗

PubMed1999

Fetal polycystic kidney disease in oro-facio-digital syndrome type I.

We report a girl with oro-facio-digital syndrome type I (OFD I) associated with polycystic kidney disease (PKD), which was identified on fetal US and fetal MRI. After birth, the diagnosis of this X-linked dominant disorder, which is lethal in males, was achieved by recognition of facial dysmorphism, lingual hamartomas, postaxial polydactyly, brain malformations, and the existence of her deceased male sibling with similar malformations. Adult PKD is a common feature in heterozygous females with OFD I. However, fetal PKD has been reported only in a lethal homozygous male. Our observation expands our knowledge about the phenotypic variations of PKD in OFD I.

Female↗

PubMed1999

The radiological findings in chronic expanding hematoma.

OBJECTIVE: To identify the characteristic MRI findings of chronic expanding hematoma correlated with the pathology. DESIGN AND PATIENTS: Three patients who had a chronic expanding hematoma involving the musculoskeletal system were reviewed retrospectively. RESULTS AND CONCLUSION: Huge soft tissue masses suggestive of malignancy with destruction of the bony structure were revealed on radiography and computed tomography. MRI showed the masses to exhibit heterogeneous signal intensity on both T1 and T2-weighted images with a peripheral rim of low signal intensity, reflecting the central zones of fluid collection due to fresh and altered blood with a wall of collagenous fibrous tissue. These MRI findings were seen in all three patients and are considered to be characteristic; they assist in differentiation from neoplasm in consideration of the history of trauma or surgery.

Aged↗

PubMed1999

A case of old trapezoid fracture.

We studied a rare case of old dorsal displacement fracture of the trapezoid. Favorable results were obtained with sugical reduction, despite the fracture being old.

Adult↗

PubMed1999

Placenta accreta/increta. Review of 10 cases and a case report.

A review of the patients seen at the Department of Obstetrics at Dokkyo University Hospital who had suffered placenta accreta/increta in the past 18 years, was performed. There were 10 such cases out of 9,716 deliveries during this period. This incidence is higher than that which has been reported in other Western countries. Forty percent of the patients in our study had placenta accreta/increta accompanied by placenta previa or low lying; 30% had had a prior cesarean section (C/S); 70% had previously experienced dilatation and curettage (D & C); 80% had previously undergone a C/S and/or D & C: and 40% had a history of miscarriage. Three of the ten patients with placenta accreta/increta required a hysterectomy; 2 patients were successfully treated with hemostatic stitches on the endometrium; and the remaining 5 mild cases were treated with removal of the placenta, either manually or with the use of forceps. There was no case of maternal death. In 2 cases, neonatal asphyxia was noted, but the neonate immediately recovered.

Adult↗

PubMed1999

Biological effects of ion beams in Nicotiana tabacum L.

The biological effects of ion beams on Nicotiana tabacum L., particularly the induction of chromosome aberrations, were investigated. Dry seeds were exposed to 12C5+, 4He2+ and 1H+ beams with linear energy transfer (LET) ranging from 1 to 111 keV/microm and irradiated with gamma-rays. Ion beams were more effective in reducing germination and survival of the seeds than gamma-rays. The LD50 for 12C5+ beams, 4He2+ beams and gamma-rays were 35, 60 and 500 Gy, respectively. The frequencies of mitotic cells with chromosome aberrations, such as chromosome bridges, acentric fragments and lagging chromosomes in the root tip cells of the exposed seeds, increased linearly with increasing doses. Relative biological effectiveness (RBE) values, based on the doses that induced a survival inhibition of 50% and a 10% frequency of aberrant cells, were 14.3-17.5 for the 12C5+ beams, 7.0-8.3 for the 4He2+ beams and 7.8 for the 1H+ beams. Furthermore, the relative ratios of the chromosome aberration types were significantly different between the ion beam and the gamma-ray regimes: chromosome fragments were more frequent in the former, and chromosome bridges in the latter. Based on these results, we concluded that the repair process of initial le

Cell Division↗

PubMed1999

Systemic granulomatous arteritis associated with Epstein-Barr virus infection.

A 61-year-old woman initially presented with symptoms and findings reminiscent of infectious mononucleosis, and her illness then took a rapidly fatal course. Autopsy revealed widespread granulomatous arteritis, with multinucleated giant cells but without eosinophils and fibrinoid necrosis, affecting small arteries and arterioles and infiltration of haemophagocytic histiocytes into many organs. In situ hybridization with Epstein-Barr virus (EBV)-specific oligonucleotide probes showed positive signals in the infiltrating immune cells and epithelial and endothelial cells of the affected organs. EBV-associated haemophagocytic syndrome (EBV-AHS) with systemic granulomatous arteritis was diagnosed. From the immunophenotypes of the infiltrating immune cells, a possible role of CD4+ T-cells in the pathogenesis of this haemophagocytic syndrome and granulomatous vasculitis was suggested.

Arteritis↗

PubMed1999

Mucin-producing biliary papillomatosis associated with gastrobiliary fistula.

We report a case of mucin-producing biliary papillomatosis in a 78-year-old woman. Abdominal ultrasound (US) and computed tomography (CT) showed wall thickening and dilatation of the intrahepatic bile duct (IHBD), as well as a nodular lesion, 1.2 cm in diameter, in the left branch of the IHBD. Gastric endoscopy revealed excretion of bile-containing mucin on the anterior wall of the body of the stomach. Endoscopic ultrasonography (EUS) showed gastrobiliary fistula and discharge of mucin into the stomach. Needle biopsy of the biliary tumor revealed papillary proliferation, but no malignant cells were recognized histologically. Therefore this patient was diagnosed as having mucin-producing biliary papillomatosis forming gastrobiliary fistula. She did not present with obstructive jaundice, probably because of the fistula. She is alive, without obstructive jaundice, 16 months after the diagnosis without having had surgery. This is, to our knowledge, the first reported case of biliary papillomatosis forming gastrobiliary fistula and with the patient free of obstructive jaundice.

Aged↗

PubMed1999

Reresection for local recurrence of rectal cancer.

Local recurrence is one of the major reasons that rectal cancer surgery is unsuccessful. The aim of this study was to investigate the surgical characteristics of patients undergoing reresection for local recurrence of rectal cancer. A total of nine patients were enrolled in this study, six of whom underwent total pelvic exenteration, one, posterior exenteration, one, abdominoperineal resection with sacral resection, and one, lymph node dissection alone. The mean operative time was 8 h 15 min, and the mean operative blood loss was 2 325 ml. Although major postoperative complications occurred in four patients (44%), there were no postoperative or hospital deaths. Lateral lymph node metastasis was detected in all four patients whose lateral lymph nodes were dissected or extirpated at the reresection. Two patients survived for more than 5 years without rerecurrence, and the cumulative 5-year survival rate was 26%. The para-aortic lymph nodes were the most common site of first rerecurrence. The results of this study indicate that patients who undergo reresection for local recurrence of rectal cancer are at high risk of devel-oping lateral or para-aortic nodal metastasis. Nevertheless, reresection may be a therapeutic option for the local recurrence of rectal cancer.

Adenocarcinoma↗

PubMed1999

Gait analysis following varus osteotomy of the femur for hip osteoarthritis.

The purpose of this study was to evaluate differences in the gait patterns of healthy and osteoarthritic hips, and changes in these patterns after intertrochanteric varus osteotomy of the femur, in relation to the strength of the muscles around the hip joint. We measured the strength ratio of hip abductor muscles, temporal and distance factors, and pelvic movement, and carried out dynamic electromyography (EMG) in 24 women who underwent unilateral varus osteotomy of the femur for hip osteoarthritis (OA), 30 non-surgically-treated women with hip OA, and 54 healthy women. The stance phase time was shorter and the strength ratio of hip abductor muscles was lower in the operated patients than these values in the other two groups, changes in pelvic obliquity and tilt were smaller, and changes in the percent maximum voluntary contraction of the gluteus medius and tensor fascia latae muscles were greater than these values in the healthy subjects. This study showed the postoperative reappearance of the simulated conditions in the hip before varus osteotomy of the femur, providing evidence that the pelvis was horizontally maintained during walking due to the decreased stance phase time and increased performance of the hip abductor muscles achieved after this procedure.

Adult↗

PubMed1999

Experimental application of microwave tissue coagulation to ventricular myocardium.

BACKGROUND: It is difficult to create transmural lesions in a beating, normothermic perfused heart. The aim of this study was to evaluate the effect of microwave tissue coagulation on a beating heart. METHOD: We used a microwave tissue coagulator that emits microwaves of 2,450 MHz. Studies were conducted on 30 mongrel dogs weighing between 9 and 13 kg, and microwave tissue coagulation was performed at the free wall of the left ventricle in a beating heart without cardiopulmonary bypass. RESULTS: Microwave tissue coagulation created transmural degenerated lesions in the left ventricle without risk of ventricular rupture. The lesion width of microwave ablation increased from 10 to 60 seconds. Histologic examinations revealed well-demarcated areas of heat degeneration consisting of coagulation necrosis and contraction band necrosis of the myocardium. The lesion healed to hard scar tissue, which was sharply demarcated from the normal myocardium. No animals had inducible ventricular tachycardia through programmed ventricular stimulation. CONCLUSIONS: Microwave ablation with a monopolar antenna created transmural lesions with only a few proarrhythmic events occurring during ablation.

Animals↗

PubMed1999

Radial approach: a new concept in surgical treatment for atrial fibrillation. II. Electrophysiologic effects and atrial contribution to ventricular filling.

BACKGROUND: In a previous study the atrial incisions that follow the concept of the radial approach were designed according to the activation sequence during sinus rhythm and the atrial coronary artery anatomy in normal dogs. The purpose of the present study was to determine whether the radial approach provides a more physiologic activation sequence and atrial transport function than the maze procedure. METHODS: Ten dogs that had undergone the radial approach (n = 5) or the maze procedure (n = 5) were studied 6 weeks postoperatively. Sinus node function and inducibility of atrial fibrillation were examined before and after operation. The atria were mapped endocardially with 212 electrodes, and atrial activation sequences during sinus rhythm and right atrial pacing were examined. Atrial transport function was assessed by transepicardial Doppler echocardiography. RESULTS: No dogs developed sinus node dysfunction postoperatively. Both the radial approach and the maze procedure equally prevented sustained atrial fibrillation. The atrial activation sequence was more synchronous after the radial approach than after the maze procedure. There was no electrically isolated region after the radial approach. The total activation time of the left atrium was significantly shorter after the radial approach than after the maze procedure (53.6+/-9.8 versus 70.5+/-9.6 ms, p<0.05). The ratio of peak flow velocity of the E wave to the A wave (peak E/A) of the transmitral Doppler flow was significantly smaller after the radial approach than after the maze procedure (1.7+/-0.4 versus 3.5+/-1.7, p<0.05). The atrial filling fraction of the transmitral Doppler flow was significantly larger after the radial approach than after the maze procedure (29.9%+/-7.3% versus 14.8%+/-5.0%, p<0.01). There was no significant difference in peak E/A and atrial filling fraction of the transtricuspid Doppler flow between the two procedures. CONCLUSIONS: The radial approach provides a more synchronous activation sequence and atrial transport function, and thus may represent a more physiologic alternative to the maze procedure as a surgical treatment for atrial fibrillation.

Atrial Fibrillation↗

PubMed1999

Biocompatibility of a silicone-coated polypropylene hollow fiber oxygenator in an in vitro model.

BACKGROUND: A silicone-coated microporous hollow-fiber membrane oxygenator has been developed to prevent plasma leakage during long-term use. The objective of this study was to evaluate the biocompatibility of the oxygenator. METHODS: A silicone-coated oxygenator was compared with an uncoated oxygenator in an in vitro model of cardiopulmonary bypass. Simulated circulation was maintained for 6 h at 37 degrees C. RESULTS: Platelet counts decreased significantly (p < 0.05) and leukocyte counts tended to decline; however, the differences between groups were not significant. Concentrations of C3a increased significantly in both groups (p < 0.05), but levels were significantly less in the silicone-coated oxygenator (p = 0.008). In contrast, concentrations of C4a, beta-thromboglobulin, and granulocyte elastase increased significantly (p < 0.05), but the differences between groups were not significant. CONCLUSIONS: Silicone coating over a microporous hollow-fiber membrane may improve biocompatibility by reducing C3a activation.

Coated Materials, Biocompatible↗

PubMed1999

Evaluation of the accuracy of preoperative staging in thoracic esophageal cancer.

BACKGROUND: Exact clinical staging before treatment of esophageal cancer has become increasingly important in the evaluation and comparison of the results of different treatment modalities, including surgery, chemotherapy, and radiotherapy. METHODS: The accuracy of preoperative tumor staging by using an esophagography, esophagoscopy, percutaneous and endoscopic ultrasonography, and computed tomography was assessed in 224 patients with resectable esophageal cancer. The results of tumor staging by these tests were compared prospectively with the pathologic stage of the esophagectomy specimens with respect to the T and N categories defined by the International Union Against Cancer TNM classification. RESULTS: For the T category, the overall accuracy was 80%. For the N category, overall accuracy was 72%, with a sensitivity of 78%, a specificity of 60%, and a positive predictive value of 78%. Overall, the accuracy of stage grouping was 56%. CONCLUSIONS: Either the T or N categories can be predicted reliably by clinical staging techniques. However, the preoperative stage grouping might not be valid in resectable, localized esophageal cancer.

Adult↗

PubMed1999

Tissue-non-specific alkaline phosphatase mRNA expression and alkaline phosphatase activity following application of retinoic acid in cultured human dental pulp cells.

Retinoic acid is a potent inducer of tissue-non-specific alkaline phosphatase (TNSALP) expression in various osteoblastic and fibroblastic cells, and may be involved in morphogenesis, cellular growth and differentiation. This study investigates the effects of retinoic acid on alkaline phosphatase activity and TNSALP gene expression in human dental pulp cells. Cultured cells were treated with various concentrations of retinoic acid (0, 10(-7), 10(- 6), 10 (-5) M) in 0.5% bovine serum albumin without serum. Alkaline phosphatase activity was determined by the rate of p-nitrophenyl phosphate hydrolysis and was also assayed in the presence of various inhibitors and under thermal inactivation. A set of specific oligonucleotide primers was selected, based on the nucleotide sequences of two human TNSALP mRNA (bone and liver) types, and reverse transcription-polymerase chain reaction (RT-PCR) performed. Inhibitory and thermal inactivation experiments revealed that the elevated alkaline phosphatase activity had properties of the TNSALP type. RT-PCR showed that retinoic acid enhanced the expression of bone-type TNSALP mRNA in pulp cells. However, the liver-type TNSALP mRNA was not detected. These findings suggest that the high alkaline phosphatase activity of retinoic acid-treated dental pulp cells is associated with increased transcription of the bone-type mRNA of the TNSALP gene and not with liver-type.

Alkaline Phosphatase↗

PubMed1999

Involvement of myosin light-chain kinase in chloride-sensitive Ca2+ influx in porcine aortic endothelial cells.

OBJECTIVES: This study was designed to investigate the involvement of myosin light-chain kinase (MLCK) in bradykinin- and thapsigargin-induced changes in intracellular Cl- and Ca2+ concentrations ([Cl-]i; [Ca2+]i) in porcine aortic endothelial cells. METHODS: Using the fluorescent probes N-ethoxycarbonylmethyl-6-methoxyquinolinium bromide (MQAE) and fura-2/AM, the effects of different MLCK inhibitors on bradykinin- and thapsigargin-induced changes in [Cl-]i and [Ca2+]i were assessed. RESULTS: Bradykinin and thapsigargin significantly decreased the MQAE fluorescence intensity, which indicates increased [Cl-]i; these changes were reversed by removal of extracellular chloride (Cl-o) and were significantly inhibited by Cl(-)-channel inhibitor N-phenylanthranilic acid but not by Na(+)-K(+)-Cl- cotransport inhibitor furosemide. Pretreatment with ML-9 and wortmannin, two different selective inhibitors of MLCK, significantly reduced these changes in a dose-dependent manner. The inhibitory effects of ML-9 and wortmannin on the Cl- responses were not significantly different and were not additive. Bradykinin and thapsigargin provoked large increases in [Ca2+]i, which were significantly diminished by removal of Cl-o and by pretreatment with the Cl(-)-channel inhibitor N-phenylanthranilic acid. CONCLUSIONS: The study shows that an increase in [Cl-]i may be involved in the Ca2+ influx in response to bradykinin and thapsigargin and that MLCK might be involved in the Cl- response. We suggest that MLCK might be involved in the Cl(-)-sensitive endothelial Ca2+ responses to bradykinin and thapsigargin.

Androstadienes↗

PubMed1999

EUS and K-ras analysis of pure pancreatic juice collected via a duodenoscope after secretin stimulation for diagnosis of pancreatic mass lesion: a prospective study.

BACKGROUND: The early diagnosis of pancreatic cancer remains problematic. This prospective study assessed the utility of a combination of endoscopic ultrasound (EUS) and genetic analysis of pure pancreatic juice in the diagnosis of pancreatic mass lesions. METHODS: One hundred seventy-six patients with suspected pancreatic disease were enrolled and underwent ultrasonography (US), computed tomography (CT), endoscopic retrograde choleangiopancreatography (ERCP), and EUS. Pure pancreatic juice was collected endoscopically after secretin stimulation. K-ras point mutations at codon 12 in the juice were assayed by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: Thirty-six (20%) patients were found to have solid pancreatic masses including 19 with cancer (7 patients, </= 2 cm) and 17 patients with an inflammatory mass (13 patients, </= 2 cm). US and CT were both less sensitive, particularly in patients with small masses. In 13 patients, small masses (4 cancer and 9 inflammatory masses) were not delineated until EUS. The combination of EUS and K-ras analysis had a high sensitivity (100%; p < 0.05 vs. US) and its accuracy reached 94% (p < 0.01 vs. US). CONCLUSIONS: EUS and K-ras determination in pure pancreatic juice collected via a duodenoscope may be useful for the diagnosis of pancreatic mass lesions.

Adenocarcinoma↗