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Biomedical subjects

M Sakurai

Publications and source records attributed to M Sakurai.

At least 541 records · Page 30Linked to original sources
PubMed1991

Construction and functional characterization of mutants of the bovine leukaemia virus trans-activator protein p34tax.

The p34tax protein [p38tax, p34, p38(XBL), XBL-I] of bovine leukaemia virus (BLV) activates transcription from the BLV long terminal repeat (LTR) promoter. To analyse the functional properties of this protein, inframe insertions and internal deletions were systematically introduced in a plasmid-encoded copy of the p34tax gene. The abilities of wild-type and mutant genes to activate gene expression from the LTR promoter linked to the chloramphenicol acetyltransferase gene and to inhibit trans-activation by the wild-type protein were studied. The trans-activating activity of 14 of the 18 mutants tested was completely abolished, but four mutants each containing a lesion in the internal portion of the polypeptide retained activity. Taken together, these results suggest the presence of an internal region of the polypeptide where structural integrity is less strictly required for the functional activity of this protein. Among the mutants incompetent in the transactivation assay, only two with mutations in the N-terminal region of the polypeptide inhibited transactivation by the wild-type protein in a dose-dependent manner. These results facilitate understanding of the physiological function of the tax protein family.

Amino Acid Sequence↗
PubMed1991

A case report of paroxysmal nocturnal hemoglobinuria in a child.

A ten-year-old boy with paroxysmal nocturnal hemoglobinuria (PNH) is described. Although hemolytic anemia was evident, Ham's test was negative and the erythrocyte acetylcholinesterase (ACHE) activity was normal at the first admission. The diagnosis of hemolytic anemia of unknown etiology was made. Methylprednisolone pulse therapy was started, but could not prevent the hemolytic crises associated with infections. Twelve months later Ham's test turned positive and ACHE activity decreased. The diagnosis of PNH was confirmed. As the disease is insidious in onset, we emphasize that a high index of suspicion and Ham's test and sucrose water test repeated at regular intervals are required to avoid missing the diagnosis.

Acetylcholinesterase↗
PubMed1991

Late effects of childhood acute leukemia and its treatment.

Late effects of childhood acute leukemia and its treatment were studied in 776 patients (684 ALL, 73 ANLL, and 9 others) in Japan who had remained in remission for more than 1 year after their first complete remission. Delayed adverse sequelae involve a wide variety of organs and their functions. Short stature was present in 2.61%, obesity in 3.79%, abnormalities of growth hormone secretion in 1.5%, delayed secondary sex characteristics in 1.5% of males and 0.6% of females, motor disturbances in 1.17%, sensory disturbances in 0.91%, intellectual and learning disabilities in 2.48%, abnormal findings in routine neurologic examinations in 1.31%, EEG abnormalities in 4.30%, brain CT abnormalities in 5.09% and cardiac dysfunction in 1.07%. Various other disorders were seen in 20 patients. Many of these delayed adverse sequelae are caused by or related to central nervous system prophylaxis and systemic combination chemotherapy. The results suggest that it is needed to improve therapeutic methods through the stratification of patients by risk factors and detailed analysis of prognostic factors. Moreover it is important to render medical and psychosocial support to long-term survivors of childhood leukemia through interactions between the patient, parents and medical staff.

Adolescent↗
PubMed1991

Left atrial myxoma metastasizing to the aorta, with intraluminal growth causing renovascular hypertension.

The first case of 'a metastatic intraluminal myxoma of the aorta' is reported. The patient was a 48-year-old man who had already developed metastases to his skin and brain from a left atrial myxoma. Then, his myxoma grew in his leg and intraluminally in the aorta and caused renovascular hypertension. Surgical removal of the tumor could relieve his hypertension, but he finally died 6 months after surgery. The findings at autopsy were described and previous reports on metastasizing left atrial myxomas were also reviewed.

Aorta, Abdominal↗
PubMed1991

Hyperimmunoglobulinemia D following cancer chemotherapy.

Five classes of serum immunoglobulin levels were investigated in 107 children with malignant or benign tumors. Hyperimmunoglobulinemia D (hyper-IgD) was observed in 31 of 82 children who were in complete remission off chemotherapy with a median follow-up of 4.5 years after cessation of chemotherapy. On the other hand, hyper-IgD was not found among 12 children with malignant or benign tumors treated with chemotherapy and a low incidence of hyper-IgD was observed during chemotherapy (1 of 13 cases). The result indicates that hyper-IgD is not uncommon in children off chemotherapy, suggesting that dysregulation of IgD synthesis persists long after cessation of antineoplastic drugs.

Adolescent↗
PubMed1991

Bone formation on synthetic precursors of hydroxyapatite.

The aim of this study was to investigate the reaction of skeletal tissue to various synthetic calcium phosphate (Ca-P) compounds in vivo. Five synthetic Ca-P compounds were implanted into the subperiosteal area of the calvaria of 7-week-old BALB/c mice for one to 15 weeks. Synthetic compounds were dicalcium phosphate (DCP), octacalcium phosphate (OCP), amorphous calcium phosphate (ACP), Ca-deficient hydroxyapatite and hydroxyapatile (HA). Implanted DCP, OCP and ACP were found to be converted to apatitic phase by x-ray microdiffraction analysis using undecalcified specimens. Structure of bone was found out on all of Ca-P compounds eventually at late stage under the light microscope, but the rate of bone formation calculated from a number of experiments varied on respective synthetic Ca-P compound. It was high as 80% for DCP, OCP and ACP, but was low as 5.6% for Ca-deficient HA, and no reaction was found for HA at the stage of 3 weeks. Fine filaments and granular materials in the newly formed bone matrix were detected at 7 days around the remnants of OCP particles which already converted to apatitic phase by ultrastructural study of decalcified specimens. These structures were very similar to the components of bone nodules seen in intramembranous osteogenesis. It is postulated that the precursors of HA have an important role in intramembranous osteogenesis.

Animals↗
PubMed1991

Hemifacial spasm due to cerebellopontine angle epidermoid tumor--case report.

The authors report a case of cerebellopontine angle epidermoid presenting as typical hemifacial spasm. A 33-year-old male had experienced intermittent right hemifacial spasm for 2 years. Cranial nerve examination was otherwise normal, including auditory and trigeminal nerve functions. Metrizamide computed tomographic cisternography and magnetic resonance imaging demonstrated a characteristic epidermoid tumor. The tumor was totally removed. Postoperatively, no facial spasm or other facial nerve dysfunction was noted.

Adult↗
PubMed1991

Intracellular dCTP/ara-CTP ratio and the cytotoxic effect of ara-C.

In this study, the relationship between the dCTP/ara-CTP ratio and the cytotoxic effect of cytosine arabinoside (ara-C) was investigated. Intracellular levels of dNTPs and ara-CTP were analyzed by high-performance liquid chromatography. Although doubling time and intracellular dCTP levels were different in each of the cells, there was a consistent relation between the intracellular dCTP/ara-CTP ratio and the cytotoxic concentration of ara-C. These data suggest that the intracellular dCTP/ara-CTP ratio is one of the important factors for considering the cytotoxic action of ara-C.

Arabinofuranosylcytosine Triphosphate↗
PubMed1991

[Clinical study on low body temperature in health subjects].

During last year, 931 men aged 51.0 +/- 9.5 years participated in our hospital's 3-day health screening. Their axillary temperature were taken 3 times per day (twice each, at 6:00 a.m., 2:00 p.m. and 6:00 p.m.) during their 3-day stay and the mean axillary temperature was determined for each subject. In 72 among all subjects, the mean axillary temperature was below 36 degrees C. These 72 subjects were classified as low-temperature individuals with normal temperature below 36 degrees C. This study was designed to compare low-temperature subjects with mean axillary temperature, on various factors, such as age, degree of obesity, liver function, renal function, lipids, electrolytes, and biochemical data (blood glucose, serum amylase, and CPK). This study also included seasonal changes in these low-temperature subjects. The following results were obtained. 1) Age was most closely related to low-axillary temperature, and the degree of obesity (modified Broca-Katsura method) had second significant relation. The low-axillary temperature was in common in subjects over 60 years and was also common in obese subjects, regardless of their age. 2) No seasonal effect was observed with low-temperature subjects. 3) Only the age and the degree of obesity (modified Broca-Katsura method) showed negative correlation independently with the mean axillary temperature. (For age, the correlation coefficient was Y = -0.006539X + 36.491, while for obesity it was Y = -0.004536X + 36.203.) Therefore the older and the more obese the subjects, the lower the mean axillary temperature.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[A case of small cell carcinoma originating at the site of pneumoplication of giant bulla five years later].

A 64 year-old man was performed pneumoplication for his left-sided giant bulla on December 15, 1983. After five years, consciousness loss and right hemiplegia occurred. Brain CT revealed a cystic lesion with enhancement in the left occipital lobe. Brain biopsy disclosed metastatic small cell carcinoma. Lung biopsy showed the same histopathology, so primary lesion was considered to be from the site of the previous pneumoplication. Lung cancer associated with emphysematous bulla have been mostly characterized by tumor shadow or niveáu in the bulla. In this case, the postoperative infiltrating shadow of pneumoplication had made early diagnosis difficult.

Carcinoma, Small Cell↗
PubMed1991

Effect of sodium bicarbonate and deoxycholic acid on the gastric mucosa of the rabbit.

Deoxycholic acid (DC), a secondary bile acid and one of those most toxic to the gastric mucosa, is precipitated and becomes inactive in the acidic lumen of the rabbit stomach. We sought to determine whether or not oral administration of sodium bicarbonate (NaHCO3) and DC injure the rabbit gastric mucosa. Rabbits were divided into six groups. Group 1 was given 10 ml of 10% NaHCO3 followed by 50 ml of 20 mM DC orally every day. These animals had diarrhea and three of five died on the fourth or fifth day. Therefore, the two remaining animals were killed on the fourth day. Animals in group 2 were given 10 ml of water followed by 50 ml of 20 mM DC, those in group 3 were given 10 ml of 10% NaHCO3 followed by 10 mM DC, those in group 4 were given 10 ml of water followed by 50 ml of 10 mM DC, and those in group 5 were given 10 ml of 10% NaHCO3 followed by 50 ml of the DC solution. Group 6 was not treated. Although all animals in the group 2 and one of three in group 3 had diarrhea, they were alive and were killed after eight or nine days. Gross and histological examinations showed that the degrees of gastric mucosal damage in groups 1 and 2 were more severe than in groups 3 and 4. Mucosal damage in group 3 was more severe than in group 4. The gastric mucosa in group 5 was similar to that in untreated animals (group 6). These data suggest that when the gastric lumen is alkalinized by NaHCO3, DC causes more severe damage to the mucosa than it does when the lumen is acidic.

Animals↗
PubMed1991

Detection of hepatitis C virus antibodies and hepatitis C virus RNA in patients with alcoholic liver disease.

The relationship between alcoholic liver disease and hepatitis C virus was studied in 80 patients by searching for hepatitis C virus RNA with the polymerase chain reaction and by measuring hepatitis C virus antibodies. By C-100 enzyme-linked immunosorbent assay, hepatitis C virus antibodies were found in 2 of 10 patients with fibrosteatosis, 8 of 20 patients with alcoholic hepatitis, 14 of 19 patients with chronic hepatitis and 19 of 31 patients with cirrhosis. Percentages of patients with antibodies found by C-100 radioimmunoassay and by enzyme-linked immunosorbent assay based on sequence peptide 42 were lower; of the 16 patients with a low titer by C-100 enzyme-linked immunosorbent assay, 10 were negative by radioimmunoassay and 6 were negative by sequence peptide 42. By a second-generation recombinant immunoblot assay, hepatitis C virus antibodies were found in 1 of 10 patients with fibrosteatosis, 2 of 20 patients with alcoholic hepatitis, 15 of 19 patients with chronic hepatitis and 18 of 31 patients with cirrhosis. Hepatitis C virus RNA was found in 1 of 10 patients with fibrosteatosis, 3 of 20 patients with alcoholic hepatitis, 13 of 19 patients with chronic hepatitis and 20 of 31 patients with cirrhosis. Of the 37 patients with hepatitis C virus RNA, 31 had antibodies by C-100 enzyme-linked immunosorbent assay (25 patients at a high titer [cut-off index greater than 6]), and 31 had antibodies by second-generation recombinant immunoblot assay. Patients with cirrhosis and hepatitis C virus RNA had higher ALT activity than such patients without hepatitis C virus RNA (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[A clinical study on renal cell carcinoma].

A retrospective study was carried out on 95 patients affected with renal cell carcinoma (RCC) between January 1973 and December 1988. Male to female ratio was 3 to 1 and the average age was 61 years. Hematuria was the most common initial symptom (44 patients, 46.3%), followed by incidental findings (18 patients, 18.9%). Five- and 10-year survival rates for all patients with RCC were 51.9 and 37.1%, respectively. Five-year survival rates for stage I, II, III, and IV were 82.7 54.7, 20.0, and 4.7%, respectively. Statistical analyses identified variables that significantly influenced survival, including lymph node metastasis (p less than 0.01) and distant metastasis (p less than 0.01). Cell type and renal vein involvement did not influence survival significantly. The three different forms of therapy (mitomycin therapy vincristine therapy and immunological therapy) did not influence survival significantly, but the beneficial effect of VBL therapy was obtained.

Carcinoma, Renal Cell↗
PubMed1991

Effects of topical application of UF-021, a novel prostaglandin derivative, on aqueous humor dynamics in normal human eyes.

The mechanism underlying the intraocular pressure (IOP) lowering effect of a prostaglandin-related compound, isopropyl 20-ethyl-9 alpha,11 alpha-dihydroxy-15-keto-cis-delta 5-prostanoate (UF-021), and its possible adverse effects in long-term use were studied in normal human eyes. A single instillation of 0.12% UF-021 significantly lowered IOP without affecting aqueous flow rate, tonographic C value or episcleral venous pressure. Protein concentration in the anterior chamber and corneal endothelial permeability to fluorescein remained unaffected. It was suggested that UF-021 lowers IOP mainly by increasing uveoscleral outflow. Twice daily application of 0.12% UF-021 for 4 weeks caused no significant changes in aqueous protein concentration, aqueous flow rate or corneal endothelial permeability. Neither single nor long-term use of topical UF-021 induced irritative responses in the outer segment of the eye. The present study suggests that UF-021 has potential as a safe and effective ocular hypotensive drug with a mechanism of action different from other drugs currently available for the treatment of glaucoma.

Administration, Topical↗
PubMed1991

Bending and torsion fractures in long bones (a mechanical and radiologic assessment of clinical cases).

Long bone injuries in clinical cases are studied by comparison of roentgenograms with a rational mechanical analysis of the injuries. Fractures produced by torsional loads have a spiral shape with a smooth and even surface. Fractures induced by bending loads have uneven and rugged fracture surfaces perpendicular to the bone axis. Long bones are weak in torsion but strong in tensile stress produced by bending. This result corresponds to the clinical fact that a large direct external force is needed to produce a transverse fracture while a spiral fracture is produced by a relatively small torque.

Adolescent↗
PubMed1991

[An 8; 21 chromosome translocation associated leukemia presenting with large intestinal granulocytic sarcoma: a report of two cases].

Two patients of acute myelogenous leukemia (AML) presented with a large intestinal tumor and related symptoms. They had a tumor in the rectum or the ascending colon. Bone marrow cells obtained from both patients showed a karyotype with t(8;21). Chromosomal findings in the former patient has already been reported in detail (Am J Hematol 4, 273, 1978). These findings and reports in the literature indicate that large intestinal tumor may not be rare in AML with an 8;21 translocation. Complete remission was achieved after chemotherapy, when their intestinal tumors disappeared.

Adult↗