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Biomedical subjects

M Sakurai

Publications and source records attributed to M Sakurai.

At least 433 records · Page 24Linked to original sources
PubMed1993

A study on diurnal fluctuation of blood-aqueous barrier permeability to plasma proteins.

The diurnal change of blood-aqueous barrier permeability to protein molecules was investigated in 20 eyes of 10 normal volunteers. Simultaneous determinations of aqueous flow rate and the coefficient of entry into the anterior chamber (k(in)) for plasma protein were performed at different times of the day: (a) 0800 to 1100 hr; (b) 1900 to 2200 hr of the same day; (c) 0800 to 1100 hr of the next day; (d) 1400 to 1700 hr 1 week later; and (e) 0200 to 0500 hr of the following morning. Aqueous flow rate was determined by fluorophotometry and k(in) was calculated for each period from flow rate, plasma protein concentration, anterior chamber volume and aqueous protein concentration measured with a laser flare-cell meter. Calculated values for k(in) did not fluctuate significantly among the periods, and there were no significant changes in anterior chamber volume or plasma protein concentration. Aqueous protein concentration and flow rate showed diurnal fluctuations, the patterns of which inversely corresponded to each other. It was concluded that permeability of the blood-aqueous barrier to protein remains fairly stable over a 24-hr period and the diurnal variation of aqueous protein concentration is mostly attributable to that of aqueous flow rate.

Adult↗
PubMed1993

Radical resection of primary malignant melanoma of the gallbladder with multiple metastases: report of a case.

We present herein an usual case of primary malignant melanoma of the gallbladder in a 51-year-old man in whom an exploratory laparotomy for melena revealed six malignant melanoma lesions located in the gallbladder, main pancreatic duct, stomach, duodenum, jejunum, and a mesenteric lymph node. Total pancreatectomy was performed and histologically, junctional activity was seen only in the gallbladder, suggesting that this was the primary site. No melanotic lesions were found on the skin or eyes. The metastases to the main pancreatic duct and gastrointestinal tract appeared likely to have occurred as a consequence of the mucosal dissemination of the tumor cells shed into the bile. The post-operative course was uneventful and combined chemotherapy was administered for 16 months. No new metastatic lesions were found until 21 months postoperatively, when metastases were detected in the brain and thoracic spinal cord. These metastatic tumors were removed surgically, but the patient died from cerebral disturbance 26 months after the initial operation. Thus, we consider that aggressive surgical therapy was effective for extending the survival time and improving the quality of life of this patient.

Adult↗
PubMed1993

Low R-wave amplitude in the right precordial leads in children with symptomatic doxorubicin cardiomyopathy.

Electrocardiographic (ECG) findings were studied in four patients with doxorubicin cardiomyopathy. In all patients with congestive heart failure (CHF), the ECGs had a low R-wave and low R/S ratio in lead V1. Our study suggests that increased injury to myocardial cells in the regions of the anterior septum and anterior left ventricular wall may be important in the pathogenesis of doxorubicin cardiomyopathy. Eight years later, cardiac recovery from CHF occurred with a normal ECG and left ventricular ejection fraction in one patient, indicating that CHF may be reversible in certain cases.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Autopsy case of hepatocellular carcinoma associated with lupoid hepatitis and complicated by malignant lymphoma.

An 81-year-old woman in whom liver dysfunction had been pointed out 3 years previously was diagnosed as having liver cirrhosis due to lupoid hepatitis. Considering the poor prognosis of cirrhosis and her age, immunosuppressive therapy was not adopted. Nine months later, a small liver tumor was found by ultrasonography and was diagnosed as hepatocellular carcinoma (HCC). The tumor was treated with transcatheter arterial embolization, but grew continuously. She also developed gingival lymphoma that was successfully treated. Three years after initial diagnosis of lupoid hepatitis, she died of hepatic failure. An autopsy was performed and confirmed the clinical diagnosis, liver cirrhosis with HCC. HCC is regarded as a rare complication of lupoid hepatitis, but cases of HCC complicating lupoid hepatitis may increase with progress in treatment methods and elongation of survival. The present case suggests that any malignancy can be developed in long-term surviving patients with lupoid hepatitis.

Aged↗
PubMed1993

Long-term therapeutic efficacy of interferon for patients with chronic hepatitis C.

Interferon is being used for therapy of chronic hepatitis C, but its long-term results have not been reported. We studied 65 patients with this disease who were monitored for at least 2 years after completion of the therapy. Almost all patients who had responded to therapy at 6 months after the end of therapy had normal levels of alanine aminotransferase (ALT) when evaluated later. The level of ALT became normal for the first time in some patients more than 6 months after therapy ended. The level of ALT in many of the patients without HCV RNA had become normal 6 months after the end of the therapy. One of three schedules was employed: three times weekly long-term; daily for two weeks and none for two weeks in a cycle; and daily for several weeks; 57%, 29%, and 17% of the patients on these schedules came to have normal ALT levels. Patients without HCV RNA at six months after completion of therapy tended to have higher responses in terms an increased level of 2',5'-oligoadenylate synthetase of mononuclear cells in vitro before therapy began. However, therapy three times per week was effective even for some patients judged not responsive to IFN by this test. The results showed that IFN therapy was effective for chronic hepatitis C when judged by long-term results.

Adult↗
PubMed1993

Human promyelocytic cell line HL60 has the specific binding sites for prolactin and its ornithine decarboxylase, DNA synthesis and cellular proliferation are induced by prolactin.

Human prolactin (hPRL) induced ornithine decarboxylase (ODC) activity, subsequently DNA synthesis and cellular proliferation on human promyelocytic cells, HL60, cultured in a serum-free medium. HL60 cells had 2100 specific binding sites for hPRL per cell, showing a dissociation constant of 1.1 x 10(-10) M. Binding of 125I-PRL to the cells was not blocked by simultaneous addition of human growth hormone. ODC activity and DNA synthesis were activated maximally at 5 and 20 h, respectively, after the addition of 0.05 nM hPRL. These effects of PRL on cellular proliferation, ODC activity and DNA synthesis were abolished by the simultaneous addition of anti-hPRL antibody. Simultaneous addition of an irreversible inhibitor of ODC, difluoromethyl ornithine (DFMO), also abolished the inductions of ODC and DNA synthesis by hPRL. The inhibitory effect of DFMO on hPRL-induced DNA synthesis was reversed by the addition of putrescine to the culture medium. These results suggest that hPRL binds to the prolactin receptor on HL60 cells and induces ODC activity to increase cellular polyamine levels, which eventually stimulates DNA synthesis and cellular proliferation.

Binding Sites↗
PubMed1993

Maclura pomifera agglutinin-binding glycoconjugates on converted apatite from synthetic octacalcium phosphate implanted into subperiosteal region of mouse calvaria.

We have previously shown that the mineral in granules of synthetic octacalcium phosphate (OCP) implanted subperiosteally in mouse calvariae was converted to apatitic crystals and that the OCP implantation stimulated bone formation. The matrix components accumulated on the converted apatite were very similar to those of bone nodules (starting locus of calcification) in intramembranous osteogenesis. In the present study, the nature of the matrices accumulated on OCP implants in calvariae was compared with that of the matrices accumulated in abdominal subcutaneous implants. The comparison was facilitated by the use of Maclura pomifera agglutinin (MPA) lectin which is known to have a high affinity for the primary intramembranous bone matrix. Micro-beam x-ray diffraction indicated conversion of the implanted OCP to apatitic crystals in situ, both in subperiosteal and subcutaneous sites, after 10 days. Additional bone formation was detected on the converted apatite after 13 days in subperiosteal implantation, whereas bone was not formed in the subcutaneous implantation. MPA reaction was strongly manifested after 10 days in matrices accumulated on the converted apatite in both subperiosteal and subcutaneous implantations. Biochemical data showed that intensely and weakly MPA-blotted molecules (53.0 and 152.6 kDa, respectively) were in all the mouse sera, in the guanidine HCl-EDTA extracts of mouse calvarial bone and in the extracts of the implanted OCP in both subperiosteal and subcutaneous sites. These findings indicated that the glycoconjugates accumulated on the converted apatite from OCP were similar to the glycoconjugates in the serum in terms of reactivity with MPA and molecular weights. Furthermore, the results suggest that MPA-binding glycoconjugates which had accumulated on the converted apatite may be a requisite for the differentiation of mesenchymal cells into osteoblasts in periosteum but not in subcutaneous sites.

Animals↗
PubMed1993

Inhibition of varicella-zoster virus (VZV) glycoprotein expression by a human monoclonal antibody against VZV glycoprotein III.

Effects of human monoclonal antibodies (MAbs) against varicella-zoster virus (VZV) glycoproteins (gp) on VZV glycoprotein expression were analyzed by flow cytometry. Human embryonic fibroblast (HEF) cells were inoculated with cell-free VZV and cultured in the presence of human MAbs. While human MAbs directed against gpI (V2) and -II (V1) did not affect VZV expression, a human MAb against gpIII (V3) inhibited expression of VZV gpI, -II, -III, and -IV. V3 also inhibited spread of VZV from infected to uninfected cells. Interferon-alpha, -beta, and -gamma and tumor necrosis factor-alpha were able to synergize with V3 and inhibit VZV gp expression. These results suggest that human MAb V3 may be useful for passive prophylaxis against VZV infection and for treatment of severe VZV infection.

Antibodies, Monoclonal↗
PubMed1993

One-stage anterior and posterior correction of severe kyphosis of the cervical spine in neurofibromatosis. A case report.

A case is presented of a 29-year-old woman with neurofibromatosis, who had a 100 degrees dystrophic kyphosis of the cervical spine and was successfully treated by a one-stage anterior and posterior correction. Anterior distractive and posterior compressive corrections were simultaneously applied keeping the posterior longitudinal ligament intact. The kyphosis was corrected to 42 degrees. Safety and better results of the one-stage correction of kyphosis is based on a concept of shortening the spinal canal.

Adult↗
PubMed1993

Deletion of WT1 and WIT1 genes and loss of heterozygosity on chromosome 11p in Wilms tumors in Japan.

Six of 39 sporadic Wilms tumors had gross homozygous or hemizygous WT1 and WIT1 deletions. Two Wilms tumor-aniridia-genitourinary abnormalities-mental retardation syndrome patients had total hemizygous WT1 and WIT1 deletions in both constitutional and nonsporadic type tumor cells. Four of the 8 tumors with WT1 and WIT1 deletions showed loss of constitutional heterozygosity (LOH) for markers limited to the 11p13 region. Seven of 19 Wilms tumors with neither WT1 nor WIT1 deletions also had LOH on 11p; 4 in the 11p15-11p13 region, one in the 11p15 and possibly also 11p13 regions, and two solely in the 11p15 region. Thus, 15 of the 41 Wilms tumors (37%) had WT1 and WIT1 deletions or LOH on 11p, and only 2 of the 27 tumors whose nonneoplastic normal tissues were available for study showed LOH limited to the 11p15 region. None of the 7 non-Wilms childhood renal tumors showed WT1 or WIT1 deletions, or LOH on 11p. These data suggest that Japanese Wilms tumors may be characterized by a higher incidence of the gross WT1 deletion and a lower incidence of LOH limited to the 11p15 region than the Caucasian counterparts. These molecular-genetic features may be contributing to the lower incidence of Wilms tumors in Japanese children than in Caucasian ones.

Blotting, Southern↗
PubMed1993

Primary cutaneous T-cell-rich B-cell lymphoma.

A 61-year-old man presented with a skin tumour in the right axilla of 2 months' duration. An excision biopsy revealed a malignant lymphoma, of diffuse mixed small and large cell type, morphologically suggestive of T-cell lymphoma, but shown to be a T-cell-rich B-cell lymphoma by subsequent immunohistochemical staining. A review of the literature revealed 47 cases of T-cell-rich B-cell lymphoma with descriptions of primary sites, 35 nodal and 12 extranodal, of which only one was a cutaneous primary.

Diagnosis, Differential↗
PubMed1993

Role in growth regulation of cytokines and cytokine receptors in acute lymphoblastic leukaemia expressing myeloid markers.

The biological roles of cytokines and cytokine receptors were examined in acute lymphoblastic leukaemia cells expressing myeloid antigens (My+ ALL). Interleukin-3 (IL-3), granulocyte-colony stimulating factor (G-CSF), granulocyte-macrophage-CSF (GM-CSF), and low molecular-weight B-cell growth factor (LW-BCGF) could induce DNA synthesis in certain cases of My+ ALL. Whereas in My- ALL the stimulatory effects were shown only with LW-BCGF. Acute myelogenous leukaemia (AML) cells were activated with multiple cytokines including interleukin-1 (IL-1), IL-3, G-CSF and GM-CSF. Specific receptors for IL-1 and IL-3 were strongly expressed on both My+ and My- ALL cells. These receptors, however, were weakly detectable on AML cells. Additionally we studied the production of tumour necrosis factor-alpha and IL-1 by leukaemic blasts and found that distinct amounts of both cytokines were released from My+ ALL cells and AML cells, but not from My- ALL cells. The profiles of cytokines and cytokine receptors expressed by My+ ALL showed both similarities and differences to those in My- ALL or AML. The proliferation of My+ ALL cells was dependent on multiple cytokines that would regulate growth and maturation in a lineage-restricted fashion. These data suggested that My+ ALL cells might originate from uncommitted haematopoietic precursor cells coexpressing features of both lymphoid and myeloid lineages.

Antigens, CD↗
PubMed1993

The in vivo and in vitro postantibiotic effect of aminoglycosides using a clinically isolated micro-organism.

We reported a case of abscess in which Serratia marcescens was isolated as the causative organism. We measured the postantibiotic effect (PAE) of dibekacin (DKB) and gentamicin (GM) against S. marcescens and studied the relationship between the clinical effect and the PAE. The minimal inhibitory concentration (MIC) of DKB against S. marcescens was 6.25 micrograms/mL and the serum concentration 30 min after infusion of 100 mg DKB was 5.99 micrograms/mL. The abscess was cured by the administration of DKB every 12 h. The PAE in vivo was 2.5, 2.9 and 3.3 h when DKB was administered at 50 mg/kg, 100 mg/kg and 200 mg/kg, respectively. This PAE is one of the reasons that infection can be effectively treated with intermittent administration, even if the serum concentration is below the MIC.

Abscess↗
PubMed1993

Moyamoya disease associated with bilateral renal artery stenosis.

Recent research has suggested that an association exists between moyamoya disease and fibromuscular dysplasia which involves systemic vessels, including renal arteries. We report a 3 year old girl with moyamoya disease associated with bilateral renal artery stenosis. This case may support the common etiology of these two clinical conditions. To our knowledge this is the youngest case of moyamoya disease associated with bilateral renal artery stenosis.

Aortography↗
PubMed1993

Infectious diseases in African children.

Present status and problems of infectious diseases in African children are detailed. The Department of Paediatrics, Mie University School of Medicine has 10 years' experience of international medical cooperation with African countries. At present, the department is participating in two projects in Ghana and Zambia. The activities have been carried out in the field of priority infectious diseases in African children. Major infectious diseases in Africa are malaria, diarrhoeal diseases, acute respiratory infections and some specific parasitic diseases. Human immunodeficiency virus infection has also become a threat to the health and survival of children in Africa. To reduce morbidity and mortality due to these diseases, primary health care activity may be an effective and economical measure. Japan is expected to make further technological and economical contributions to the control of the infectious diseases in developing countries. Japanese paediatricians should be aware of the condition of child health in developing countries and consider what can be done to help.

Child↗
PubMed1993

Spatial features of calcium transients during early and delayed afterdepolarizations.

Although changes in intracellular Ca2+ concentration ([Ca2+]i) are spatially heterogeneous during spontaneous contraction in mammalian cardiac muscle, it has not yet been observed how [Ca2+]i changes spatially within cardiac myocytes during delayed (DADs) and early (EADs) afterdepolarizations. The aim of this study is to characterize the spatial features of the increase in [Ca2+]i during such afterdepolarizations and to understand the ionic mechanisms responsible for them. Myocytes were enzymatically isolated from guinea pig ventricles and loaded with fura 2-acetoxymethylester, the Ca2+ fluorescence indicator dye. Membrane potential was recorded with a conventional microelectrode technique, and spatiotemporal changes in fura 2 fluorescence and cell length were recorded using a digital television system. After superfusion with potassium-free Tyrode solution, DADs and EADs were induced. During DADs, fluorescence transients were heterogeneous within myocytes (n = 11). Furthermore, they often propagated within myocytes as if they were "waves." In contrast, during EADs, fluorescence transients showed no waves within myocytes but rather showed synchronous changes throughout the myocytes (n = 15). The results of this study suggest that the spatial features of the increase in [Ca2+]i differ between the DADs and EADs. We concluded from these differing features that the ionic mechanisms responsible for the two triggered activities are different.

Animals↗