Biomedical subjects

H Ashida

Publications and source records attributed to H Ashida.

At least 19 recordsLinked to original sources

PubMed1992

[CT of intestinal injuries following blunt trauma].

We retrospectively reviewed 53 CT scans in 42 patients with surgically proven intestinal injury following blunt abdominal trauma. Free air and localized low density fluid were specific signs of intestinal injury. Free peritoneal fluid without a known source, thickened bowel wall, and thickened mesentery were non-specific ones. Specific and non-specific findings were demonstrated in six (22%) and 23 (85%) of 27 CT scans performed within four hours following trauma, and 19 (73%) and 26 (100%) of 26 CT scans performed after four hours, respectively. CT is useful for the diagnosis of blunt intestinal injuries, but early diagnosis is difficult because of the lack of specific signs.

Abdominal Injuries↗

PubMed1992

[MR imaging of corpus callosal injuries].

The MR imaging and CT findings of corpus callosal injury were analyzed in 32 of 224 patients with acute head injuries. MR imaging was more sensitive than CT in the detection of callosal injuries. All 9 hemorrhagic lesions were visualized on both MR imaging and CT. Fifteen of 23 nonhemorrhagic lesions were not visualized on CT, although all nonhemorrhagic lesions were visualized on MR imaging. Twenty-four lesions of the corpus callosum were located in the splenium, but no lesion was located in the rostrum. Diffuse axonal shear injuries were visualized in 25 patients with callosal injury as associated traumatic lesions. Twenty-three patients with callosal injury had low initial Glasgow Coma Scale scores (less than 9), but 9 patients had high scores. Associated diffuse axonal shear injuries, especially in the brain stem could be a possible explanation for this difference. MR imaging is useful to detect traumatic lesions of the corpus callosum.

Accidents, Traffic↗

PubMed1992

[Clinical application of 31P MRS to malignant liver tumors--with an emphasis on evaluation of response to therapy].

Malignant liver tumors in 19 cases (13 hepatomas and 6 metastatic tumors) were studied by 31P magnetic resonance (MR) spectroscopy. Five healthy volunteers were also studied. Volume localization was performed using the ISIS sequence. Compared with normal liver, the MR spectra of malignant tumors showed an elevated phosphomonoester (PME) peak relative to beta ATP (p less than 0.005), and tumors were slightly alkaline (pH 7.32 +/- 0.08) before therapy. Nine cases of hepatomas responding to chemoembolization showed extremely reduced signal intensity of spectra. Tumor pH was compared before and after therapy in four cases that showed good response to therapy, and was elevated in all of them. Three metastatic tumors with good response showed reductions in PME and ATP after therapy. MR spectroscopy with adequate localization technique is useful in demonstrating the response of malignant tumors to therapy.

Carcinoma, Hepatocellular↗

PubMed1992

Purification and characterization of membrane-bound endoglycoceramidase from Corynebacterium sp.

Endoglycoceramidase catalyzes the hydrolysis of the linkage between oligosaccharides and ceramides of various glycosphingolipids. We found that a bacterial strain Corynebacterium sp., isolated from soil, produced endoglycoceramidase both intracellularly and extracellularly. The intracellular enzyme bound to the cell membrane was solubilized with 1% Triton X-100 and purified to homogeneity about 170-fold with 60% recovery. The molecular mass of the enzyme was approximately 65 kDa. The enzyme is most active at pH 5.5-6.5 and stable at pH 3.5-8.0. Various neutral and acidic glycosphingolipids were hydrolyzed by the enzyme in the presence of 0.1% Triton X-100. Ganglio- and lacto-type glycosphingolipids were readily hydrolyzed, but globo-type glycosphingolipids were hydrolyzed slowly.

Carbohydrate Sequence↗

PubMed1992

[Evaluation of non-contrast-enhanced CT in blunt abdominal trauma].

We compared the findings of noncontrast-enhanced CT with those of contrast-enhanced CT in 126 patients with blunt abdominal trauma to evaluate the usefulness of noncontrast-enhanced CT. In 112 of the patients, visceral injuries were confirmed by surgery or clinical follow-up including CT. Although noncontrast-enhanced CT diagnosed all patients with 12 intestinal injuries requiring immediate surgery, contrast-enhanced CT missed two of these patients because high density hematomas on noncontrast-enhanced CT became isodense after IV administration of contrast material. However, contrast-enhanced CT was superior to noncontrast-enhanced CT in the diagnosis of hepatic and renal injuries. A case of renal artery occlusion was only visualized on contrast-enhanced CT. We conclude that both noncontrast- and contrast-enhanced CT should be performed for the CT evaluation of blunt abdominal trauma.

Abdominal Injuries↗

PubMed1992

[Signal contamination problem in three-dimensional localization technique of MR spectroscopy--experiment and an analysis of patient data].

Signal contamination from the surrounding volume was studied using the ISIS sequence, a three-dimensional localization technique. In phantom experiments, contamination decreased with the increase of Tr, regardless of where the contamination originated from. In 52 localized liver spectra with a Tr of 2 sec, PCr contamination was estimated at 3 to 4%, and contamination of ATP signals from the surrounding liver tissue at less than 1%, because of the relatively short T1 of ATP in the liver. In the spectra of brain neoplasms obtained using the simultaneous double-volume selection technique, the PCr ratio in the tumor relative to the control area was high in low grade astrocytoma (0.80, n =8) and low in others (0.45, n = 11). Considering contamination and spectral noise, a PCr ratio of less than 0.4 does not strongly suggest the existence of PCr in tumors. Among 25 cases whose therapeutic processes were monitored by MRS, signal disappearance was observed in two cases in the localized spectra after therapy. In both of them, tumor necrosis was proved pathologically and correlated well with spectroscopic findings. It was found that the ISIS technique suppressed signal contamination to the level of several percents, providing spectra of acceptable quality through localization.

Humans↗

PubMed1992

What is the clinical disadvantage of discarding old radiographs? Survey of patients not re-examined for a long time.

The clinical disadvantage of discarding old radiographs was evaluated in patients who had not been re-examined for more than 8 years after their last radiological examination, 38,772 in total. During the 1 year survey, 158 (0.41%) of them underwent re-examination after a long interval. Retrospective evaluation revealed that in only 12 patients (0.032%) were the old films useful. This survey suggested that the clinical risk of not referring to films more than 8 years old would be less than 0.049%. We consider this acceptable, and have formulated new guidelines of storage of films.

Evaluation Studies as Topic↗

PubMed1991

[How many years should we keep films?].

In our university hospital, all of the radiographs have been stored since the hospital opening in 1974, and they can be retrieved easily. The total number of jackets is about 230,000. Access rates to them were surveyed, and it became clear that inactive jackets were increasing with the age of the hospital. On the contrary, fraction of active jackets increased slightly. Five radiologists evaluated the usefulness of referring to the previous films in the film reading processes. Subjects were 158 patients who were examined after the interval of 8 years or more. Assuming to discard their previous radiographs, the simple inaccessibility risk was 0.41% and the risk decreased to 0.0026% taking the clinical disadvantage into consideration. Risk to research works was estimated as 0.97%. Based on these surveys and evaluations, our university decided to discard radiographs of patients who had not revisited these 10 years with the exception of important cases for researches.

Humans↗

PubMed1991

Time discrete model of recurrent inhibition in hippocampal dentate gyrus.

A time discrete model of recurrent inhibition in the hippocampal dentate gyrus is made and analyzed. This model assumes that (1) each granule cell can generate only one action potential in response to a single stimulation of the perforant path, (2) each interneuron receives synaptic inputs from many granule cells, and (3) an output of the interneuron is inhibitory for granule cells. Although each granule cell generates an action potential in the all-or-none fashion, the population spike is shown to be approximated by a piecewise linear function of the population excitatory post-synaptic potential (EPSP). From this model six patterns in the population spike responses to the paired-pulse stimulation are deduced. Each pattern is composed of some broken lines whose slopes and intercepts are explicitly expressed by the average and variance of the microscopic parameters and the population size of the cells. This model clarifies the relation between the measured quantity in the field potential experiment and the microscopic quantities peculiar to the granule cell and to the interneuron.

Action Potentials↗

PubMed1991

Target enzymes on hepatic dysfunction caused by dietary products of lipid peroxidation.

Dietary products of lipid peroxidation cause hepatic dysfunction due to decreases in the activities of some hepatic enzymes and to depletion of CoA. An idea about the decreases and depletion is that the enzymes and CoA could be injured directly by the incorporated products in the liver. Their inactivations in vitro were then examined using a reasonable amount of peroxidation products. The hepatic cytosol, microsomes, and mitochondria were incubated with 10, 15, and 20 micrograms/mg protein of peroxidation products, respectively, and changes in the enzymatic activities were monitored. Glucose-6-phosphate dehydrogenase, mitochondrial NAD-dependent aldehyde dehydrogenase, glucokinase, and glyceradehyde phosphate dehydrogenase were inactivated, and the CoA level was decreased, but the other hepatic enzymes were not. Although glyceraldehyde phosphate dehydrogenase was most sensitive to peroxidation products in vitro, the decrease in activity was not detected by the oral dose of secondary products. On the other hand, among the components of peroxidation products, hydroperoxides and polymers are not incorporated in the liver, but decomposed products of low molecular weight are incorporated. Glucokinase among the above enzymes was not inactivated by the low-molecular-weight products. It was therefore concluded that glucose-6-phosphate dehydrogenase, mitochondrial NAD-dependent aldehyde dehydrogenase, and CoA were targets of the direct attack by incorporated components of peroxidation products in the liver.

Aldehyde Dehydrogenase↗

PubMed1991

Relationship between oxidative stress and hepatic phosphoglucomutase activity in rats.

The relationship between the oxidative stress and inactivation of hepatic enzymes was examined in rats. An intake of lipid peroxidation products or pro-oxidative drugs provokes oxidative stress in the living body. Secondary peroxidation products of linoleic acid were administered orally, and the oxidative stress was evaluated by thiobarbituric acid (TBA) and haemoglobin-methylene blue (HMB) tests, and by the reduction in tocopherol level. A specific decrease in hepatic phosphoglucomutase activity was found following the oxidative stress caused by the dose with secondary products. Then, ten pro-oxidative drugs were administered intraperitoneally and the effects on the enzymatic activity were determined. Among the ten drugs, CCl4, alcohol, paraquat, phenobarbital, thiopental and methylcholanthrene caused the TBA values to increase, and the phosphoglucomutase activity to decrease, in the liver 24 h after the doses. It was attempted to clarify the inactivation mechanism by using parenchymal hepatocytes. When the cells were cultured in medium containing aldehydic products originating from lipid peroxidation, these aldehydes significantly suppressed the induction of phosphoglucomutase by dexamethasone as compared with the cells in aldehyde-free medium. We consider that aldehydes inhibit the hormonal induction of phosphoglucomutase in the rat liver.

Administration, Oral↗

PubMed1991

[Effect of L-carnitine in patients with ischemic heart disease].

To assess the protective effects of L-carnitine (LC) infusion on ischemic heart disease, 30 patients who had angina and ischemic ECG changes during exercise were evaluated by bicycle ergometry. They were categorized in LC and non-treatment (NT) groups. There were no significant differences in age and sex between the 2 groups. Before exercise, 15 patients (9 males and 6 females) received 60 mg/kg LC and the results including hemodynamics, coronary circulation, and cardiac metabolism at rest and during exercise were compared with those of the NT group studied in the same protocol (50 watts x to cycle, 15 min). At the end of 30 min LC drip infusion, the arterial carnitine content (LC (a)) reached 1,980 +/- 257.3 microM and then was maintained at 1,212.7 +/- 136.2 microM during exercise. There was no correlation of LC (a) with the coronary arterio-venous difference nor with myocardial uptake of LC. Although there was no significant difference in coronary blood flow (CBF: mliters/100 g/min) between the LC and NT groups at rest (LC: 92.1 +/- 29.0 vs NT: 88.0 +/- 26.5), CBF during exercise increased significantly in the LC group compared with the NT group (LC: 230.4 +/- 113.8 vs NT: 139.1 +/- 52.7; p < 0.05). In the NT group, there was no significant change in coronary arterio-venous oxygen difference ((a-cs) O2: vol %) during exercise, but in the LC group (a-cs) O2 increased significantly from 10.2 +/- 1.3 to 11.5 +/- 1.9 (p < 0.01). Furthermore, although there was no significant difference in myocardial oxygen consumption (MVO2: mliters/100 g/min) at rest between the 2 groups (LC: 9.30 +/- 2.96 vs NT: 9.71 +/- 3.09), it increased significantly in the LC group compared with the NT group during exercise (LC: 25.11 +/- 9.98 vs NT: 15.55 +/- 6.09). MVO2/LVWI (LVWI = left ventricular work index) and MVO2MT (MT = myocardial tension) did not significantly differ at rest between the 2 groups. However, these 2 indices decreased significantly during exercise (p < 0.05) in the NT group, and remained unchanged in the LC group, showing a significant difference between the 2 groups (both p < 0.05). In myocardial energy substrates, the myocardial uptake ((a-cs) x CBF) of free fatty acid (FFA: muEq/100 g/min) increased significantly in the LC group compared with that of the NT group (LC: 10.16 +/- 13.26-->31.88 +/- 27.58* vs NT: 16.02 +/- 27.92-->18.11 +/- 31.00;* = p < 0.05, LC vs NT).

Adult↗

PubMed1990

[Occlusion of fistulas with fibrin glue].

Fistula formation is one of complications after surgery. Additional surgical intervention is recommended when fistula does not respond to conservative therapy. Eight patients with fistula were treated by using a baby feeding tube or double lumen angiographic catheter with fibrin glue. All the fistulas except one were successfully treated; 6 with complete occlusion and one with decreased discharge from fistula. It is emphasized that two deep fistulas could be occluded by using angiographic technique. Our preliminary result suggests fibrin occlusion therapy of fistulas is a safe and useful procedure, and an alternative to surgery for non-curative fistula.

Aged↗

PubMed1990

Better control of esophageal variceal bleeding by sclerotherapy followed by surgery.

This paper reports the clinical results of a retrospective study comparing endoscopic injection sclerotherapy (EIS) and back-up surgical treatment after EIS in the management of acute variceal bleeding. The 74 patients included in the study were divided into 2 groups. Group I consisted of 41 patients who received EIS over a mean period of 2.2 sessions and Group II consisted of 33 patients who underwent EIS and subsequent surgical intervention, in the form of 19 distal splenorenal shunts and 14 nonshunting procedures. The overall percentage of patients in whom initial control of variceal bleeding was achieved was 91.8 per cent. Four of the Group II patients were saved by emergency nonshunting operations. Rebleeding was experienced by 4 (28.6 per cent) of the 14 patients who underwent nonshunting surgery but by only 1 (5.3 per cent) of the 19 patients who underwent selective shunt surgery. The cumulative survival in Group II was significantly superior to that in Group I with 2 year survival being achieved in 66.7 per cent of the Group II patients but in only 23 per cent of Group I patients. Thus, the combination of initial EIS and back-up surgical intervention may be more beneficial than sclerotherapy alone for patients with acute variceal bleeding, while, the distal splenorenal shunt may be a more suitable surgical technique for patients having previously EIS.

Combined Modality Therapy↗

PubMed1990

Hepatobiliary and gastrointestinal imaging after pancreaticoduodenectomy--a comparative study on Billroth I and Billroth II reconstructions.

This study was conducted to compare the passage of bile and food through the remnant alimentary tract between 2 and 6 months following pancreaticoduodenectomy in patients undergoing Billroth I (Imanaga) and Billroth II (Child) reconstructions, using dual scintigraphy. In the patients who underwent Child's operation (n = 14), hepatobiliary scintigraphy showed a prominent stasis of bile tracer in the proximal jejunal loop and a significant time delay before the bile and food became mixed at the upper jejunum. On the other hand, in the patients who underwent Imanaga's operation (n = 9) no bile stasis in the proximal jejunal loop was found and the time taken before the two agents became mixed was similar to that of healthy controls (n = 7). The time taken for the two agents to mix at the upper jejunum was 65.8 +/- 7.9 min in the patients after Child's operation, 17.3 +/- 2.5 min in those after Imanaga's operation, and 18.5 +/- 2.8 min in the healthy controls, respectively. Continuous stasis of bile in the proximal loop and severe postcibal asynchronism in patients who undergo Child's operation can therefore cause reflux cholangitis and absorptive disturbances in the long postoperative term. The results of this study suggest that Imanaga's reconstruction is a more physiological procedure than Child's reconstruction following pancreaticoduodenectomy.

Anastomosis, Surgical↗

PubMed1990

[Coronary circulation, myocardial metabolism and cardiac catecholamine flux in patients with syndrome X].

To clarify the pathogenesis of syndrome X (Sx), hemodynamics, coronary circulation, myocardial lactate metabolism and cardiac catecholamine flux were studied before and during bicycle ergometry in 25 patients (pts) and these data were compared with those in 15 with effort angina (EA) and in eight controls. The results were as follows: 1. The cardiac index during exercise decreased in EA pts probably due to their coronary lesions, while those in the controls and Sx were well preserved. 2. An increase of coronary blood flow during exercise, both in Sx and EA pts, was significantly impaired and the myocardial extraction ratio of lactic acid was significantly lower compared with those in the controls. The cardiac norepinephrine release during exercise was markedly higher in Sx, compared with that in controls and in EA. These results suggested that in Sx, excessive sympathoadrenergic stimulation may play an important role in restricting coronary reserve and in accelerating myocardial anaerobic metabolism.

Angina Pectoris↗

PubMed1990

[Coronary reserve of the hypertensive heart: relationship to left ventricular hypertrophy].

We investigated the relationship between electrocardiographic left ventricular hypertrophy with ST-changes, and coronary circulation and myocardial metabolism in 25 patients with essential hypertension (systolic blood pressure greater than or equal to 160 mmHg, diastolic blood pressure greater than or equal to 95 mmHg). No patients had abnormal coronary arteriograms. They were categorized in two groups: non-hypertrophy group; cases with no hypertrophy on echocardiograms (interventricular septum and posterior wall thickness less than or equal to 11 mm), and hypertrophy group; cases with hypertrophy (wall thickness greater than or equal to 12 mm). Supine bicycle ergometry (50 watts, 50 rpm, 15 min) was performed during coronary sinus catheterization and electrocardiography. For cardiac hemodynamics, the coronary circulation and myocardial metabolism were observed at rest and during exercise. There was no significant difference in unit coronary blood flow (coronary blood flow per 100 gm) before exercise between the two groups. Unit coronary blood flow was significantly greater in the non-hypertrophy group after exercise. However, total coronary blood flow (coronary blood flow per 100 gm x left ventricular mass) showed no significant difference between the two groups. Coronary vascular resistance per 100 gm was higher in the hypertrophy group during exercise, though there was no significant difference at rest. Myocardial oxygen extraction O2 (A-C) was not different between the two groups at rest and during exercise, but unit myocardial oxygen consumption (MVO2) during exercise was higher in the non-hypertrophy group than in the hypertrophy group. The lactate extraction ratio tended to decrease in the hypertrophy group during exercise, and tended to increase in the non-hypertrophy group. Myocardial potassium flux tended to increase in the hypertrophy group during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Hemodynamic changes in splenic blood flow during and after distal splenorenal shunt.

The purpose of this study was to examine the hemodynamic changes of the spleen and the subsequent influence on the numbers of blood cells both during and 1 month after distal splenorenal shunt (DSRS) with splenopancreatic disconnection in 20 patients with portal hypertension. The intraoperative splenic blood flow, measured with an electromagnetic flowmeter, significantly increased after shunt insertion: the mean percentage increases within the splenic vein and artery were 60% (p less than 0.01) and 37% (p less than 0.05), respectively. The splenic venous blood flow, measured with a pulsed Doppler flowmeter, had not changed significantly 1 month postoperatively (676 +/- 501 to 540 +/- 306 ml/min). The WBC and platelet counts significantly (p less than 0.05 and p less than 0.01, respectively) increased 1 month postoperatively, whereas there was a small, but significant (p less than 0.05), decrease in RBC count. We concluded that splenic blood flow increases immediately after DSRS with splenopancreatic disconnection, but this increase may be only short term. The influence of the postoperative hemodynamic changes on blood cell count is uncertain.

Adult↗