Search PubMed⌕ Search

Biomedical subjects

H Honda

Publications and source records attributed to H Honda.

At least 271 records · Page 15Linked to original sources
PubMed1995

MR imaging of hepatocellular carcinoma. Correlation of metal content and signal intensity.

In order to clarify the factors contributing to the signal intensities (SIs) of HCC on T1-weighted images, the amount of water, lipid, copper (Cu), iron (Fe), and manganese (Mn) was determined in HCC and surrounding hepatic parenchyma of 13 patients. The relationships among these findings, the histopathologic findings, and the SIs of T1-weighted images were evaluated. Among the 13 HCC, 3 had a high SI, 5 were isointense, and 5 had a low SI on T1-weighted images compared to the surrounding hepatic parenchyma. The paramagnetic ions which contributed to the SI patterns were assumed to be Cu in HCC (38.0 +/- 62.4 micrograms/g ww), and Fe in the liver (61.1 +/- 42.4 micrograms/g ww) and HCC (40.0 +/- 34.3 micrograms/g ww). In 8 HCC with high- or isointensity, 2 were grades I, 5 were grade II, and one was grade III according to the Edmondson-Steiner's histopathologic classification. It is concluded that the SI patterns alone can not be a sign of low grade malignancy because of the existence of Fe in livers and HCC.

Aged↗
PubMed1995

[Selective intra-arterial injection of calcium for localization of insulinomas: proposed new criteria].

To elucidate whether noninvasive arterial stimulation venous sampling (ASVS) is helpful for localizing insulinomas, calcium gluconate (0.02-0.025 mEq Ca2+/kg) was injected directly into the gastroduodenal, splenic and superior mesenteric arteries of six patients with episodic hypoglycemia. In all six patients, there was a greater than 26-fold increase in serum insulin levels in blood samples obtained from the hepatic vein after the infusion of calcium into the artery supplying the tumor. However, in four of the six patients, such an injection into an artery not supplying the tumor resulted in a greater than twofold increase in insulin concentration. Accurate localization of the insulinomas was verified at surgery in all patients. We believe that these false positive results were caused mainly by the influx of calcium via branches of intrapancreatic anastomoses. In order to minimize false positive results, we have recommended the following new criteria for ASVS: maximum insulin concentrations exceeding 150 microU/ml in blood samples obtained from the hepatic vein, and greater than twofold increases in insulin concentration. We concluded that noninvasive ASVS is helpful in determining the location of insulinomas.

Adult↗
PubMed1995

[Abnormalities of N-linked oligosaccharide moieties of glycoproteins in patients with myotonic dystrophy].

Myotonic dystrophy (MyD) is an inheritant disease which results from an abnormal expansion of trinucleotide repeat of myotonin protein kinase. MyD has been considered as one of membrane diseases as several functional disturbances were detected on the plasma membranes in patients with MyD. We reported here that some proteins and tissues in patients with MyD took only incomplete processing of N-glycans. The characteristic feature of the oligosaccharide moieties was so unique that N-glycans of glycoproteins such as immunoglobulin G, proteins on the erythrocyte membrane and the insulin receptor revealed reduced content of N-acetylneuraminic acid and galactose. In other words, these glycoproteins in patients with MyD had N-linked oligosaccharides which terminated with N-acetyglucosamine at the non-reducing ends. These specific defect of glycosylation may indicate the disturbances of the sarcoplasmic reticulum or the Golgi apparatus and be one of the factors which construct the membrane disorder observed in patients with MyD.

Glycoproteins↗
PubMed1995

[Prognosis for myotonic dystrophy].

Although the genetic basis of myotonic dystrophy (MD) has recently been clarified, data on prognosis and causes of death are few. To assess the relation between the age of onset and the degree to which activities of daily living (ADL) were affected, we studied statistically 586 patients with MD, who were registered in the database in hospitals of Japan in 1985. Many of the young onset patients had a long duration of illness, and many of the long-term patients showed the more severely affected ADL. When we adjusted the duration of illness, using the Mantel extension method, many patients whose age of onset was older had poorer ADL than the younger onset ones. To clarify the causes of death in MD, we collected data on 72 patients who succumbed to it from answers to questionnaires sent to all councilors of the Japanese Society of Neurology and the Japanese Society of Child Neurology in 1994. Before their deaths, among 32 MD cases unable to sit up, 16 (50%) died from respiratory involvement (respiratory failure and pneumonia), 8 (25%) from dysphagia (i.e., aspiration pneumonia and choking) and 2 (6%) from cardiac involvement. Moreover, among 25 cases that could sit up, 9 cases (36%) died from dysphagia, 4 (15%) from respiratory involvement and 2 (8%) from cardiac involvement. Dysphagia and cardiac involvement are often the causes of death in the early stage. To avoid these complications, management of swallowing and careful cardiac control is essential in patients with MD.

Activities of Daily Living↗
PubMed1994

Molecular cloning, characterization, and chromosomal localization of a novel protein-tyrosine phosphatase, HPTP eta.

Protein-tyrosine phosphatases (PTPases) are considered to play an important role in signal transduction. We previously identified partial sequences of three novel PTPases in a human leukemic cell line. F-36P. We describe here cloning, characterization, and chromosomal localization of one of the newly identified PTPases, termed as HPTP eta (human protein-tyrosine phosphatase eta). The deduced amino acid sequence was composed of an extracellular region homologous to fibronectin type III repeats, a transmembrane region, and a cytoplasmic region containing a single PTPase-like domain. Based on its primary structure, this clone belongs to type-III receptor-type PTPases. The PTPase-like domain showed PTPase activity when expressed in Escherichia coli. Antibody against the extracellular region detected a protein of 220 to 250 kD in human hematopoietic cell lines expressing HPTP eta mRNA. The antibody also recognized a protein of approximately the same molecular weight in COS cells transfected with HPTP eta cDNA, indicating that the antibody specifically recognized HPTP eta gene product and that the cloned cDNA contained full-length coding region. The chromosomal localization determined by fluorescence in situ hybridization showed that the HPTP eta gene was located at chromosome 11p11.2 on the short arm of chromosome 11, which is frequently lost or deleted in human carcinomas.

Amino Acid Sequence↗
PubMed1994

Developmental expression of P0 mRNA and P0 protein in the sciatic nerve and the spinal nerve roots of the rat.

Expression of myelin P0 protein by myelinating Schwann cells in vivo is dependent on axonal influences. This report describes P0 gene expression during development of rat sciatic nerve and spinal nerve roots using Northern blotting, in situ hybridization and immunohistochemistry. We demonstrate that: (1) the appearance of P0 mRNA and P0 protein in Schwann cells during nerve development in the rat begins prenatally, at day 18 post-fertilization (E18); (2) P0 mRNA and P0 protein have essentially identical developmental profiles, and are expressed in Schwann cells that are many days prior to myelin formation; (3) initial P0 gene expression is greatest in Schwann cells at the periphery of nerve bundles and in Schwann cells in contact with motor axons; (4) the decline in P0 expression with nerve maturation is accompanied by a sharp decline in P0 message levels in most Schwann cells, but a small subpopulation of these cells continue to synthesize very high levels of P0 mRNA. This study provides data on myelin P0 protein gene expression and distribution during PNS development and adds further insights into the axonal influences controlling Schwann cell behaviour during myelination of the rat PNS.

Aging↗
PubMed1994

Laparoscopic cholecystectomy: a report of 409 consecutive cases and its future outlook.

A retrospective study was conducted on 409 patients who underwent laparoscopic cholecystectomy at Teikyo University Hospital between May, 1990 and October, 1992. The operation had to be converted to an open cholecystectomy in ten of these patients because of uncontrollable bleeding from the cystic artery in one, venous bleeding due to portal hypertension in one, extensive adhesions of the omentum and the duodenum to the gallbladder in two, extensive adhesions around the gallbladder in four, and extensive adhesions between the gallbladder and the common bile duct (CBD) in two. The time taken to complete the procedure ranged from 30 to 235 min, the average time being 81 min, and the postoperative hospital stay ranged from 3 to 56 days, the average stay being 6.5 days. Eleven patients developed complications intra- or postoperatively: bile duct injury which became manifest after the operation and required laparotomy in three patients; injury to the right hemidiaphragm resulting in a right pneumothorax in one; periumbilical subcutaneous emphysema in one; mild bile leaks which resolved in a few days in two; and a severe bile leak which resolved after 6 days in one. The indications for laparoscopic cholecystectomy have widened with experience and now, CBD stones and a history of previous gastrectomy are no longer contraindications for laparoscopic cholecystectomy. Thus, it seems that laparoscopic cholecystectomy can be performed as safely as a standard cholecystectomy, provided the patients are selected properly and appropriate caution is exercised.

Adolescent↗
PubMed1994

Effect of trimebutine maleate on the contractile response of the isolated ileum from diabetic rats.

1. Tension of the isolated ileum from diabetic rats induced by streptozotocin was measured isometrically to study the mode of action of trimebutine maleate (TMB). 2. The hyperreactivity of contractile response to KCl was observed in the isolated ileum from diabetic rats. TMB inhibited the contraction induced by KCl and acetylcholine (ACh) in normal solution. 3. In Ca2+ free solution, the hyperreactivity of contractile response to KCl was attenuated, and TMB did not inhibit the contraction induced by KCl. In contrast, TMB inhibited the contraction induced by ACh even in Ca2+ free solution. 4. These results suggest that the hyperreactivity of contractile response to KCl in the ileum from diabetic rats is due to the enhancement of Ca2+ influx through voltage-dependent Ca2+ channel and that TMB inhibits the hyperreactivity of contractile response through the inhibition of Ca2+ movement by the cell.

Animals↗
PubMed1994

Simulation study on heart failure: effects of contractility on cardiac function.

Using the model proposed by Beyar and Sideman, the effect of maximum isometric active stress at optimal sarcomere length (sigma 0) on left ventricular (LV) function was examined. Comparing the results of calculated LV function with those of reported experiments, sigma 0 was shown to be a potential indicator of myocardial contractility, and the model of Beyar and Sideman successfully predicted LV function with various myocardial contractilities. The LVP compensation curve, which describes the relationship between sigma 0 and maximum LV pressure, was then hypothesized. The combination of the Beyar-Sideman model and the LVP compensation curve enabled the prediction and approximation of the actual process of deterioration in heart failure. These models represent a step towards a fundamentally new concept in the current clinical situation of compensated heart failure and also in evaluating the process of heart failure.

Computer Simulation↗
PubMed1994

Simulation study on the effect of external vibration on left ventricular function: potential indicator of LV tolerance to the sudden reduction of myocardial contractility.

In a previous study the authors reported that external mechanical vibration applied to the left ventricular (LV) epicardium induces contractility-dependent depression in LV pressure, stroke volume and stroke work. It was suggested that this depression may be caused by the direct effect of external vibration on contractile protein. In another paper in this issue, it is proved that LV function with various myocardial contractilities and the actual process of deterioration in heart failure are well simulated in the model proposed by Beyar and Sideman, after some modifications have been made. In the study reported here it is assumed that an external mechanical vibration induces sudden reduction in myocardial active stress in the model of Beyar and Sideman; in this way the contractility-dependent effect of external vibration on LV function has been simulated. The results of this simulation support the suggestion that external mechanical vibration directly affects contractile protein and reduces LV function, and it is further suggested that the reduction of LV function induced by external vibration reflects the reserve or tolerance capacity of LV to a sudden reduction of myocardial contractility.

Animals↗
PubMed1994

Comparative effects of loperamide hydrochloride on prostaglandin E1-induced contraction in isolated fundus and ileum of guinea pigs.

The tension of isolated preparations of the fundus and the ileum of guinea pigs was measured isometrically to study the specific effect of loperamide hydrochloride on prostaglandin E1-induced contraction. Prostaglandin E1 caused concentration-dependent contraction in both the fundus and the ileum, and there was no significant difference between the fundus and the ileum. Loperamide hydrochloride inhibited prostaglandin E1-induced contraction in the fundus and the ileum. From the pD'2 value, loperamide hydrochloride caused greater inhibition of the contraction in the ileum than in the fundus. In a Ca(2+)-free solution containing 0.1 mM EGTA, prostaglandin E1-induced contraction in the ileum was almost eliminated, whereas 58% of the contraction in the fundus still remained. In Ca(2+)-free solution, loperamide hydrochloride and verapamil hydrochloride had no influence on prostaglandin E1-induced contraction, but markedly inhibited Ca(2+)-induced contraction. These results suggest that loperamide hydrochloride shows regional differences between gastrointestinal smooth muscles contracted by prostaglandin E1, and this may reflect one of the mechanisms in its antidiarrheal action through the suppression of peristalsis.

Alprostadil↗
PubMed1994

Vascular access device for treatment of cancer patients.

Vascular access devices that are completely implanted have been used for treatment of cancer patients. Vascular access devices are useful for transarterial infusion of anticancer drugs, intravenous hyperalimentation, and drainage of bile juice in obstructive jaundice. These systems have several advantages in the care of patients: they are sealed, they have no external tubes, and they may be useful for blood or biliary sample and intravenous hyperalimentation or chemotherapy. There are only minimal discomforts related to the implantation procedure and no need for routine external catheter care. Most importantly, the quality of the patient's life is dramatically improved without external tubes. For these reasons, we believe that vascular access devices should be indicated for patients with malignant tumors as much as placement of these devices is technically feasible.

Bile↗
PubMed1994

Unusual findings on PET study of a patient with posterior cortical atrophy.

We present a patient with posterior cortical atrophy in whom positron emission tomography (PET) showed unusual findings. This 65-year-old man had a 5-year history of slowly progressive apperceptive visual agnosia and Balint syndrome, but with a relatively well-preserved intelligence and language ability even in the later stages of illness. No relevant features in this patient or his family were identified. Laboratory and radiographic investigations indicated that cerebral damage was due to primary degeneration. His symptoms resembled those of patients with posterior cortical atrophy. A PET study revealed that cerebral metabolism was reduced in the dorsal regions of the entire cortex and asymmetrical with the main site of damage on the right. The severity in asymmetry increased dorsally. These 2 types of predilection for dorsal regions had not previously been reported in such patients. These unusual PET findings may indicate the presence of pathological changes not yet identified.

Aged↗
PubMed1994

Colonic submucosal tumors: comparison of endoscopic US and target air-enema CT with barium enema study and colonoscopy.

PURPOSE: To compare the imaging characteristics of colonic submucosal tumors at endoscopic ultrasound (US) and target air-enema computed tomography (TACT) with those at conventional double-contrast barium enema study and colonoscopy. MATERIALS AND METHODS: Twenty consecutive patients with suspected colonic submucosal tumors at barium enema study and colonoscopy underwent endoscopic US, TACT, or both. Morphologic features and posture-related change in shape of tumor were evaluated with barium enema study, color and consistency of tumor with colonoscopy, internal echogenicity of tumor and layer of origin in normal colonic wall with endoscopic US, and CT attenuation number with TACT. RESULTS: Eight lipomas, seven carcinoids, three leiomyomas, four lymphangiomas, and one hemangioma were found at histologic examination. Lipomas and lymphangiomas had characteristic findings at endoscopic US and TACT. The differential diagnosis of the other submucosal tumors was facilitated by using endoscopic US. CONCLUSION: Endoscopic US and TACT may play a valuable role in the evaluation of colonic submucosal tumors.

Adult↗