Biomedical subjects
Publications and source records attributed to Y Hata.
We treated tattoos with a new method in which the epidermis of the tattooed skin was replaced after removing the dermis, which contained tattoo pigments. The separation of the epidermis from the dermis was performed enzymatically with the use of dispase. The time required for healing of the wound was markedly shortened.
The ulnar arterial circulation to bilateral hands of 683 men and 787 women was assessed with the Allen radial artery compression test. Of the 2,940 arms, the Allen test showed abnormalities in 105 (3.6%). The incidence of abnormality generally increased with age: 2.2% in the first decade and 6.9% after the ninth decade. It is very likely that circulatory failure in the hand develops after several decades among those whose radial artery was removed in their youth. When the radial artery is removed in the young, attention should therefore be paid to future consequences.
Metabolic disturbances of pancreatic hormones in obstructive jaundice in infancy were evaluated experimentally and clinically. In our experimental study, using young rats, the level of plasma insulin (IRI) gradually increased after ligation of the common bile duct. These levels were a little lower than those in the non-treated controls. The level of plasma glucagon (IRG) increased remarkably 4 weeks after ligation of the common bile duct. Clinically, there were no significant differences in the levels of IRI and IRG among normal controls and cases of neonatal hepatitis and congenital biliary atresia (CBA). In CBA patients, these levels can be correlated with the progression of hepatic fibrosis; an increase in IRG and a decrease in the IRI/IRG mol ratio was noticed in patients with grade III of hepatic fibrosis. These results indicate that, in obstructive jaundice in infancy, the more severe the hepatic damage due to obstructive jaundice, the higher the level of plasma glucagon concentration will rise.
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We recently purified to near homogeneity a novel type of regulatory protein for smg p25A, a ras p21-like GTP-binding protein, from bovine brain cytosol. This regulatory protein, named smg p25A GDP dissociation inhibitor (GDI), regulates the GDP-GTP exchange reaction of smg p25A by inhibiting dissociation of GDP from and subsequent binding of GTP to it. In the present studies, we isolated and sequenced the cDNA of smg p25A GDI from a bovine brain cDNA library by using an oligonucleotide probe designed from the partial amino acid sequence of purified smg p25A GDI. The cDNA has an open reading frame that encodes a protein of 447 amino acids with a calculated Mr of 50,565. This Mr is similar to those of the purified smg p25A GDI estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and sucrose density gradient ultracentrifugation, which are about 54,000 and 65,000, respectively. The isolated cDNA is expressed in Escherichia coli, and the encoded protein exhibits GDI activity. smg p25A GDI is hydrophilic overall, except for one hydrophobic region near the N terminus. smg p25A GDI shares low amino acid sequence homology with the Saccharomyces cerevisiae CDC25-encoded protein, which has been suggested to serve as a factor that regulates the GDP-GTP exchange reaction of the yeast RAS2-encoded protein, but not with the beta gamma subunits of GTP-binding proteins having an alpha beta gamma subunit structure, such as Gs and Gi. The smg p25A GDI mRNA was present in various tissues, including not only tissues in which smg p25A was detectable but also tissues in which it was not detectable. This fact has raised the possibility that smg p25A GDI interacts with another G protein in tissues in which smg p25A is absent.
We encountered a patient with acute cauda equina syndrome. The clinical course, laboratory data and imaging study, including magnetic resonance imaging (MRI) strongly suggested that this episode was caused by a vascular disorder of the conus medullaris. We emphasized the diagnostic usefulness of MRI in the vascular disease of the conus medullaris as well as the clinical importance of this disease in the differential diagnosis of acute cauda equina syndrome.
The penetration by bacteria through dentinal tubules was studied using a device that included portion of bovine anterior teeth. Strains of 4 genera, Streptococcus mutans, Lactobacillus casei, Staphylococcus aureus and Escherichia coli, were used for the experiment, and the effects of acid etching of dentin on the penetration of bacteria through the dentin was examined. The time required for penetration through dentinal tubules of acid-etched samples was shorter than that of unetched samples. The minimum time required for half the samples to become positive for bacterial penetration through dentin MPT50 was 4 hours for all strains chosen when the acid-etched dentin was the target. In non-acid etched samples, the MPT50 varied among the genera and ranged from 20 hours to 48 hours; the speed of penetration was Sta. aureus = L. casei greater than Str. mutans greater than E. coli. Observation under the scanning electron microscope indicated that the smeared layer was completely coated on the surface of the prepared cavity, and when bacterial penetration occurred, a portion of the smear layer on the dentin disappeared. In longitudinal sections, the penetration by the bacteria into the tubules was visible. From these results, it is suggested that the smeared layer have an important effects on bacterial penetration through these tubules.
A highly skilled surgical technic is an important factor for the success of implant. But the heat generation during bone preparation will greatly affect the healing process of bone and prognosis of implant. In this study, the heat occurrence and distribution during bone preparation which performed on an in vitro mandible model (ribs of pig) were considered with the aid of a real-time thermography. IMZ implant drills and bur, designed for cylindrical type implant were used for the bone preparation. The conclusion are as follows: 1. Any drill or bur generates higher heat without water irrigation. 2. Heat distribution produced different shape of range according to different type of drills. 3. On a relationship of preparating time to heat generation, spiral drill takes the longest time to complete drilling but heat rising ratio is slow. Round bur and Canon drill take short time to complete drilling but it is accompanied with rapid heat rising.
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There has been a reluctance to perform percutaneous ethanol injection therapy on lesions located on the surface of the liver because of the possibility of complications. We treated 16 lesions located on the surface of the liver in 14 patients by percutaneous ethanol injection and evaluated the complications and efficacy. Bleeding and seeding of malignant cells did not occur in any case. However, transient pain after injection of ethanol was more intense in these patients than in those whose lesions were not on the surface of the liver. Histopathologic examinations, imaging findings, and decrease in the serum alpha-fetoprotein levels showed that percutaneous ethanol injection was effective for tumors located on the surface of the liver. Our experience suggests that percutaneous ethanol injection can be performed safely even when lesions are located on the surface of the liver.
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Although sonographically guided percutaneous ethanol injection therapy has been attracting a great deal of attention in the treatment of liver neoplasms, few reports regarding long-term results of this therapy have been published. We report here our 4-year experience, in which ethanol injection was performed 419 times on 108 lesions in 77 patients with hepatocellular carcinoma. Histopathologic examination performed in 14 cases after the therapy revealed that the lesion was completely necrotic in 10 cases, 90% necrotic in three cases, and 70% necrotic in the remaining case. Angiography performed after the therapy showed complete disappearance of tumor stain in 37 of 42 cases treated with ethanol injection. CT after the therapy showed no enhancement of the treated lesion in 55 of 56 cases. Elevated serum levels of alpha-fetoprotein decreased in 21 of 24 cases. Ethanol injection improved the long-term prognosis of the patients. Among the 50 patients in whom there were three or fewer lesions and all lesions were treated by ethanol injection, the 1-, 2-, 3-, and 4-year survival rates were 89%, 74%, 68%, and 60%, respectively. Factors that significantly affected the prognosis were the goal of the treatment, liver function, and size of the largest lesion. Serious complications rarely occurred even in patients with severe liver dysfunction. Percutaneous ethanol injection therapy appears to be valuable for treatment of hepatocellular carcinoma.
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We performed neurovascularized free rectus abdominis muscle transplantations in two patients with chronic facial palsy. In one patient, the postoperative course was uneventful, but the patient died from rupture of esophageal varices. In the other patient, both morphologic and functional results were satisfactory. Therefore, the rectus abdominis muscle is considered to be a suitable donor for muscle transplantation for the treatment of chronic facial palsy. The rectus abdominis muscle is advantageous in that (1) simultaneous operations by two teams are possible with the patient in the supine position, (2) it is supplied by long nerves and long and large vessels, (3) it is flat and consists of segments with appropriate lengths, (4) the force and distance of contraction are appropriate, and (5) the tendinous intersections are suitable for anchoring sutures.
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Holter monitorings were performed on 2733 cases (male 1547, female 1186; age 16-92 yrs.) from 1973 to 1986 in our hospital. Among these cases, 18 patients (0.66%) died suddenly (group A), 47 patients (1.72%) died of cardiac failure (group B) and 142 patients (5.27%) survived irrespective of the presence of advanced arrhythmias (group C). To evaluate the precipitating factors for sudden cardiac death (SD), underlying diseases, electrical instability and clinical characteristics were compared between each group. 1. The incidence of coronary artery disease (CAD) was 6 cases (33.3%) in group A, 13 cases (27.8%) in group B and 70 cases (49.3%) in group C. There were no significant differences in the incidence of CAD between each group. 2. The incidence of ventricular tachycardia (VT) was 5 cases (27.8%) in group A, 13 cases (27.7%) in group B and 33 cases (23.2%) in group C. Paroxysmal atrial fibrillation (PAf) also showed the higher incidence in group A. 3. The subjects older than 60 years old were 4 cases (22.2%) in group A, 30 cases (63.8%) in group B and 60 cases (42.2%) in group C. The sex ratios were higher in male (over 60%) in 3 groups than in female. 4. In patients with CAD, VT showed higher incidence in SD (3/6 cases (50.0%)), cardiac death (CD) (6/13 cases (46.2%)) and those who survived with myocardial infarction (11/30 cases (36.7%)). 5. In patients with CAD, the reproducibility of advanced arrhythmias was found in 1/3 cases (33.3%) for SD and in 6/9 cases (66.7%) for CD. 6. Heart rate variability evaluated by RR50 (total number of changes in successive RR intervals greater than absolute value of 50 msec.) showed smaller value in the night (3:00 a.m.) than in the daytime (3:00 p.m.) in the patients with SD and CD. The night value of RR50 was significantly lower in patients with SD than in patients with CAD (p less than 0.05). The above results suggest that the presence of coronary artery disease, VT, PAf, decrease in RR50 at night and sex (male) will be precipitating factors for sudden cardiac death.