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Biomedical subjects

H Naito

Publications and source records attributed to H Naito.

At least 145 records · Page 8Linked to original sources
PubMed1996

Lack of p16/CDKN2 alterations in thyroid carcinomas.

Exons 1-3 of the p16/CDKN2 gene and exons 4-9 of the p53 gene were screened for mutations by single-strand conformation polymorphism (SSCP) analysis and direct sequencing of PCR-amplified DNA from human primary thyroid carcinomas and thyroid carcinoma cell lines. The samples included 21 papillary carcinomas, 2 undifferentiated carcinomas, 1 follicular carcinoma, 1 medullary carcinoma and 2 cell lines originating from thyroid undifferentiated carcinomas. No homozygous deletions and mutations in the p16/CDKN2 were observed in any of the primary tumors or cell lined. In contrast, one of the two undifferentiated carcinomas an both cell lines demonstrated point mutations in the p53 gene. These results that p16/CDKN2 gene alteration is not required for malignant transformation in the thyroid, while p53 gene mutations may play a role in the progression from differentiated to undifferentiated carcinoma.

Adenocarcinoma, Follicular↗
PubMed1996

Psoas abscess complicating Crohn's disease: report of two cases.

We report herein the cases of two patients with Crohn's disease complicated by a psoas abscess. The first patient was a 29-year-old man who underwent definitive surgery after acute inflammation had been controlled by nutritional therapy. In the second patient, a 37-year-old man, the abscess required drainage under local anesthesia prior to surgery. Both patients have been free from recurrence of any abdominal symptoms for about 2 years since undergoing surgery. Although psoas abscess is still regarded as a rare complication, with the increasing prevalence of Crohn's disease in Japan it has become one of the most important complications requiring surgical intervention.

Adult↗
PubMed1996

Extended strictureplasty for multiple short skipped strictures of Crohn's disease.

PURPOSE: We will describe a new procedure for treatment of multiple short strictures involving a short segment of Crohn's disease. METHODS: This procedure involves the following: 1) stay sutures at the mid portion of the two strictures; 2) an antimesenteric longitudinal enterotomy of 12 cm or more; 3) two or three interrupted transmural sutures in the four lateral portions of the two stenoses; 4) a transverse running suture, according to Heineke-Mikulicz-type strictureplasty; and 5) interrupted seromuscular sutures. RESULTS: We performed four such "double Heineke-Mikulicz"-type strictureplasties in three patients with Crohn's disease without postoperative complications. CONCLUSION: This type of double Heineke-Mikulicz-type strictureplasty is suitable for multiple short skipped strictures of Crohn's disease in selected patients.

Adult↗
PubMed1996

Antinociceptive synergistic interaction between morphine and n omega-nitro 1-arginine methyl ester on thermal nociceptive tests in the rats.

PURPOSE: This study was conducted to demonstrate if subeffective dose of N omega Nitro L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, interacts with morphine when given intrathecally (IT), epidurally (EP), and intravenously (IV) to produce a synergistic antinociceptive effect in normal rats. METHODS: Chronically catheterized 72 male Wistar rats were used in this study. We measured the tail flick latency in response to thermal stimulation of the tail on a hot plate (53 degrees C), and determined dose-response functions of IT, EP and IV morphine, L-NAME, and morphine co-administered with subeffective doses of L-NAME. The antinociceptive effect was evaluated using the doses for 50% maximum probable effect (ED50). The interaction between morphine and L-NAME was evaluated using an isobolographic approach. ANOVA was used for the statistical analysis. Significance was taken at P < 0.05. RESULTS: Morphine and L-NAME produced dose-related antinociceptive effects in the IT (ED50 = 1.23 +/- 0.18 micrograms (Mean +/- SEM) and 76.0 +/- 14.5 micrograms), EP (ED50 = 32.6 +/- 2.4 micrograms and 560 +/- 97 micrograms), and IV (ED50 = 563 +/- 71.8 micrograms and 16.0 +/- 4.0 mg) groups, respectively. Co-administration of small doses of L-NAME and morphine produced reductions in the ED50 values for morphine (0.16 +/- 0.03 microgram in IT, 1.18 +/- 0.32 micrograms in EP, and 50.5 +/- 11.4 micrograms in IV groups) (P < 0.01), suggesting a multiplicative interaction of L-NAME with morphine. CONCLUSION: L-NAME has a synergistic antinociceptive interaction with morphine in response to thermal stimulation when given intrathecally, epidurally or intravenously in rats.

Analgesics, Opioid↗
PubMed1996

Acetabular labral tears: contrast-enhanced MR imaging under continuous leg traction.

OBJECTIVE: The objective of this study was to evaluate the effects of continuous leg traction on contrast-enhanced MR imaging of the hip joint and to determine whether MR imaging under these conditions is useful for demonstrating acetabular labral tears. DESIGN AND PATIENTS: Nineteen hips underwent MR imaging with a T1-weighted spin-echo sequence, followed by MR imaging under continuous leg traction after intravenous injection of gadolinium-DTPA. Joint fluid enhancement and labral contour detection were evaluated. Eleven hips had labral tears shown by conventional arthrography, arthroscopy and macroscopic surgical findings. Assessment of labral tears by MR imaging was correlated with the diagnosis based on these standard techniques. RESULTS AND CONCLUSIONS: Joint fluid enhancement was obtained in all hips at 30 min after injection. Superior and inferior labral surfaces were completely delineated in 1 hip on the unenhanced MR images, and in 7 and 13 hips, respectively, on the enhanced images under traction. The enhanced images under traction depicted 9 of the 11 labral tears. Comparison between the unenhanced image and the enhanced image under traction avoided mistaking undercutting of the labrum for a tear in 4 hips. Contrast-enhanced MR imaging under traction was valuable for detecting labral tears non-invasively and without radiation. Follow-up examinations using this method in patients with acetabular dysplasia can help to clarify the natural course of labral disorders and enable better treatment planning.

Acetabulum↗
PubMed1996

High prevalence of small LDL particles in non-insulin-dependent diabetic patients with nephropathy.

To determine whether small-sized low density lipoprotein (LDL) is associated with a high incidence of coronary heart disease in diabetic nephropathy, we measured the LDL particle size in non-insulin-dependent diabetes mellitus (NIDDM) patients with various degrees of albuminuria (n = 95) and age-, weight-matched non-diabetic control subjects (n = 31). The diabetic subjects were divided into three groups, normoalbuminuric, microalbuminuric and macroalbuminuric NIDDM, based on the amount of albuminuria. The average diameter of LDL particles was determined by non-denaturing polyacrylamide gradient (2-16%) gel electrophoresis. The plasma lipid and lipoprotein concentrations were comparable between the non-diabetic controls and normoalbuminuric NIDDM, whereas the plasma triglyceride, very-low-density lipoprotein (VLDL) or LDL concentration was significantly increased in diabetic nephropathy. The mean LDL particle size was significantly smaller in microalbuminuric NIDDM compared with the controls or normoalbuminuric NIDDM, and the LDL size was further decreased in macroalbuminuric NIDDM. The incidence of small LDL (diameter < 255 A) was remarkably increased in microalbuminuric (58%) and macroalbuminuric NIDDM (67%) compared to the control (13%) and normoalbuminuric NIDDM (27%). Corresponding to the decreased LDL size, the cholesterol content of the LDL was significantly depleted in NIDDM with nephropathy. The high prevalence of small LDL in diabetic nephropathy was also observed even when hypertriglyceridemic or hypertensive subjects were excluded from each group. The increment in triglyceride-rich lipoprotein (d < 1.006) after oral fat-loading was increased, and postheparin lipoprotein lipase activity was decreased significantly in diabetic nephropathy. These abnormalities were significantly associated with LDL particle size. Multivariate regression analysis revealed that the amount of albuminuria was closely associated with the average LDL particle size, and this association was independent of the plasma triglyceride level. Neither insulin resistance nor glycemic control was directly associated with LDL particle diameter. The present study indicates that LDL particles become smaller in diabetic nephropathy, and this may be associated primarily with abnormal triglyceride metabolism. However, in addition to hypertriglyceridemia, other metabolic abnormalities caused by diabetic nephropathy may also be involved in the pathogenesis of small LDL particles.

Aged↗
PubMed1996

Hemodynamic effects of intravenous ephedrine in infants and children anesthetized with halothane and nitrous oxide.

The aim of this study was to evaluate the effect of age on the hemodynamic responses to intravenous (IV) ephedrine in pediatric patients anesthetized with halothane, nitrous oxide, and oxygen. One hundred ten pediatric patients, ranging in age from 0.1 to 15 yr, were assigned to receive 0.1 mg/kg (n = 55) or 0.2 mg/kg (n = 55) IV ephedrine. General anesthesia was maintained with 1.0 minimum alveolar anesthetic concentration (MAC) of halothane and 67% nitrous oxide in oxygen after tracheal intubation. Measurements of arterial blood pressure and heart rate were made at 1-min intervals for 10 min after ephedrine 0.1 or 0.2 mg/kg was injected IV as a bolus. Significant correlations were noted between age and changes in mean blood pressure (r = 0.37, P < 0.01 for the subjects receiving ephedrine 0.1 mg/kg; r = 0.63, P < 0.001 for the subjects receiving ephedrine 0.2 mg/kg), but not between age and changes in heart rate. The present results indicate that age correlates with the pressor but not the chronotropic effects of ephedrine in pediatric patients anesthetized with 1 MAC halothane and nitrous oxide.

Adolescent↗
PubMed1996

Clonidine modulation of hemodynamic and catecholamine responses associated with hypoxia or hypercapnia in dogs.

BACKGROUND: Hypoxia or hypercapnia elicits cardiovascular responses associated with increased plasma catecholamine concentrations, whereas clonidine, an alpha(2)- adrenergic agonist, decreases plasma catecholamine concentrations. The authors examined whether systemic clonidine administration would alter the hemodynamic and catecholamine responses to hypoxia or hypercapnia in anesthetized dogs. METHODS: Pentobarbital-anesthetized dogs whose lungs were mechanically ventilated were instrumented for measurement of mean arterial pressure, heart rate, mean pulmonary artery pressure, right atrial pressure, cardiac output, left ventricular end-diastolic pressure, and the peak of first derivative of left ventricular pressure. The dogs were randomly assigned to receive an intravenous bolus injection of 10 microg/kg clonidine followed by continous infusion at a rate of 1 microg. kg (-1). min (-1)(clonidine-10 group, n = 7), an intravenous bolus injection of microg/kg clonidine followed by continuous infusion at a rate of 0.5 micro.kg(-).min(-1)(clonidine-5 group, n = 7), or an equivalent volume of 0.9% saline (control group = 7). Each dog underwent random challenges of hypoxia (PaO2 30, 40, and 50 mmHg) and hypercapnia (PaCO2 60, 80, and 120 mmHg). Measurements of hemodynamic and plasma norepinephrine and epinephrine concentrations were made after the loading dose of clonidine and the first and the second exposure of hypoxia or hypercapnia. RESULTS: Although significant increases from prehypoxic values in mean arterial pressure (39 +/- 10 mmHg) and plasma norepinephrine (291 +/- 66 pg/ml) and epinephrine (45 +/- 22 pg/ml) concentrations were noted during hypoxia of PaO2 30, mmHg in the control group (P<0.05), such changes were absent in both clonidine groups. During hypercapnia of PaCo2 120 mmHg, changes from prehypercapnic values in mean arterial pressure, mean pulmonary artery pressure, the peak of first derivative of left ventricular pressure, and plasma norepinephrine and epinephrine concentrations in the clonidine-10 and clonidine-5 groups were significantly less than those in the control group. Plasma clonidine concentrations in the clonidine-10 and clonidine-5 groups were 16.8 +/- 1.7 and 8.9 =/- 1.0, 42.5 =/- 2.9 and 21.5 +/- 1.5, and 51.1 +/- 3.2 and 26.7 +/- 1.0 ng/ml after the loading dose of clonidine and the first and the second exposure of hypoxia or hypercapnia, respectively. CONCLUSIONS: Systemic clonidine administration alter the hemodynamic changes associated with hypoxia or hypercapnia and suppresses plasma catecholamine responses in anesthetized dogs when a larger dose of clonidine is administered. catecholamines: epinephrine; norepinephrine.)

Adrenergic alpha-Agonists↗
PubMed1996

Normal nonuniformity of left ventricular contraction. Assessment by cine MR imaging with presaturation myocardial tagging.

PURPOSE: To identify the normal performance of left ventricular (LV) regional contraction using cine MR imaging with presaturation myocardial tagging. MATERIAL AND METHODS: Sixteen normal volunteers were examined on a 1.5 T MR system with tagging cine sequences. Tags were applied at end-diastole as 2 parallel black lines on short-axis and 4-chamber sections, and the fractional shortenings were calculated at 7 LV locations. RESULTS: The following results were obtained with significance: a transmural gradient of contractility in the short-axis section; prolonged late-systolic endocardial shortening and epicardial early termination in the free wall; initial delay of shortening in the anterior wall; apical predominance of contractility; predominance of circumferential shortening in the free wall and of meridional shortening in the septum. These findings could be associated with myocardial fiber architecture, presumed wall stress and temporal asynergy of excitation. CONCLUSION: Cine MR imaging with myocardial tagging proved to be useful in assessing the nonuniformity of LV contraction.

Adult↗
PubMed1996

Chronic bile diversion to the urinary bladder enhances cholecystokinin release and suppresses gastric inhibitory polypeptide release in dogs.

The role of intestinal luminal bile on cholecystokinin (CCK) and gastric inhibitory polypeptide (GIP) release was examined in dogs with chronic external bile diversion. In 6 mongrel dogs, cholecysto-jejuno-cystostomy (C-J-C) was performed using a small segment of the middle small intestine interposed between the gallbladder and urinary bladder with section of the common bile duct. Butter dissolved in 30 ml of lukewarm water was orally ingested before surgery, and same amount of butter solution with or without graded volumes of canine bile were orally ingested between four to six weeks after C-J-C surgery. Increases in both plasma triglyceride and GIP levels after butter ingestion were almost completely abolished by C-J-C, but they were restored by oral bile feeding in a volume-dependent manner. Both basal and fat-stimulated CCK release were enhanced significantly by C-J-C, and oral bile feeding inhibited fat-stimulated CCK release by bile in a dose dependent manner. These data suggest that intraluminal bile regulates basal and fat-stimulated CCK release and fat-stimulated GIP release in dogs.

Animals↗
PubMed1996

Detection of subtle interstitial abnormalities of the lungs on digitized chest radiographs: acceptable data compression ratios.

OBJECTIVE: To determine acceptable compression ratios for digital radiography, we evaluated the effect of data compression on the detection of subtle interstitial lung abnormalities using digitized chest radiographs. MATERIALS AND METHODS: Screen-film chest radiographs of 38 patients with subtle interstitial lung abnormalities and 40 patients with normal lung parenchyma were digitized (spatial resolution, 0.175 mm; 2000 x 2000 pixels; 10 bits per pixel) and compressed with the discrete cosine transform method at ratios of 10:1, 20:1, and 30:1. Five chest radiologists and five radiology residents examined the uncompressed and compressed digital images and rates the presence of interstitial lung abnormalities with a five-level scale of confidence. Results were analyzed by receiver operating characteristic methods. RESULTS: Overall, the interpretation of images with a compression ratio of 30:1 was significantly less accurate than that of uncompressed images (p < .05). For the five chest radiologists, interpretation of images with a compression ratio of 20:1 or 30:1 was significantly less accurate than that of uncompressed images (p < .05). However, for the five residents, no significant difference between interpretations of compressed and uncompressed images was noted (p > or = .05). CONCLUSION: These results suggest that a 10:1 data compression ratio does not influence the detection of subtle interstitial lung abnormalities. However, information that is lost with a 20:1 data compression ratio might be essential for interpretation by experienced chest radiologists.

Adult↗
PubMed1996

Decrease of serum ascorbic acid concentrations in patients with diabetic macroangiopathy.

The relationship between serum ascorbic acid (AA) and diabetic macroangiopathy was studied. Fifty-six patients with noninsulin-dependent diabetes mellitus were examined, together with 20 healthy controls matched for age against the diabetes patients. Aortic pulse wave velocity (PWV) was taken as an index of the severity of atherosclerosis. The level of serum AA in diabetic patients was significantly lower than that of the controls. Among the diabetic groups, those with elevated PWV levels by age demonstrated a significant drop in AA. No significant differences were seen in the level of serum dehydroascorbic acid (DHAA) between patients and controls, nor were there any significant differences among patient groups. The concentration of serum AA was inversely related to the risk factors of atherosclerosis, such as body mass index, Apo B/ Apo A-I ratio, thiobarbituric acid-reactive substances (TBARS), and microalbumin in urine. It was inferred from these findings that the depletion of serum AA was apparent in diabetics with advanced atherosclerosis.

Adult↗
PubMed1996

Method for quantitative estimation of position perception using a joystick during linear movement.

We designed a method for quantitatively estimating self-motion perceptions during passive body movement on a sled. The subjects were instructed to tilt a joystick in proportion to perceived displacement from a giving starting position during linear movement with varying displacements of 4 m, 10 m and 16 m induced by constant acceleration of 0.02 g, 0.05 g and 0.08 g along the antero-posterior axis. With this method, we could monitor not only subjective position perceptions but also response latencies for the beginning (RLbgn) and end (RLend) of the linear movement. Perceived body position fitted Stevens' power law, where R=kSn (R is output of the joystick, k is a constant, S is the displacement from the linear movement and n is an exponent). RLbgn decreased as linear acceleration increased. We conclude that this method is useful in analyzing the features and sensitivities of self-motion perceptions during movement.

Acceleration↗
PubMed1996

[Transition of patients with chronic neurological diseases from hospital to home].

The following steps are essential in promoting a successful transition. (1) General condition of the patient must be stable. (2) Both parents must give consent to home care. (3) One parent at least must be thoroughly trained in all aspects of care. (4) Medical supplies must be kept in the home, and home modification to provide easy access and movement should be done as much as possible. (5) A medical support system must be established; home visiting nurses must be provided; medical doctors in the neighborhood and the local ambulance dispatch center must be notified of the patient's condition in case of an emergency.

Child↗