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Biomedical subjects

K Shinohara

Publications and source records attributed to K Shinohara.

At least 217 records · Page 12Linked to original sources
PubMed1994

Direct imaging in a water layer of human chromosome fibres composed of nucleosomes and their higher-order structures by laser-plasma X-ray contact microscopy.

X-ray contact microscopy with a 300-ps-duration laser-plasma X-ray source has been used to image hydrated human chromosomes. Clearly imaged are individual nucleosomes and their higher-order particles (superbeads), elementary chromatin fibrils. c. 30 nm in diameter and their higher-order fibres of various sizes up to c. 120 nm in diameter. The results demonstrate that X-ray microscopy is now capable of opening a new path of investigation into the detailed structures of hydrated chromosome fibres in their natural state.

Cells, Cultured↗
PubMed1994

Role of penile vascular injury in erectile dysfunction after radical prostatectomy.

OBJECTIVE: To investigate the cause of erectile dysfunction after nerve-sparing radical prostatectomy for clinically localized adenocarcinoma of the prostate (stage A or B). PATIENTS AND METHODS: Erectile function was evaluated in 20 patients, mean age 65 years (range 44-74), both pre-operatively and 1 year after surgery by intracavernosal injection of a vasoactive agent (papaverine hydrochloride or prostaglandin E1) and pulsed Doppler ultrasonography. The degree of erection, the size of the cavernosal artery and penile arterial blood flow velocity were assessed. RESULTS: Results revealed that the decreased response to intracavernosal injection of a vasoactive agent was associated with a significant reduction in both the diameter and velocity of blood flow within cavernosal arteries in 40% of patients after surgery. The pathological stage of the tumour did not correlate with the degree of vascular injury. CONCLUSION: We conclude that post-prostatectomy impotence is multifactorial but vascular injury plays a substantial role.

Adenocarcinoma↗
PubMed1994

Detection of microscopic extracapsular extension prior to radical prostatectomy for clinically localized prostate cancer.

OBJECTIVE: To assess better techniques of clinical staging to identify the presence and location of extracapsular extension (ECE) and assist the surgeon in the selection of candidates for resection or preservation of neurovascular bundles during radical prostatectomy. PATIENTS AND METHODS: In a retrospective review of the records of 117 patients with clinically localized (31 T1 and 86 T2) prostate cancer treated with radical prostatectomy the results of digital rectal examination (DRE), real-time transrectal ultrasound (TRUS) and a retrospective review of static films were compared to assess their accuracy in the detection of ECE. The ultrasonic criterion for ECE was bulging or irregularity of the boundary echo adjacent to a hypoechoic lesion. On DRE, the criterion for ECE was palpable bulging of a nodule beyond the normal contour of the prostate. The reference standard was the presence and location of ECE in the whole-mount, serially sectioned radical prostatectomy specimens. RESULTS: Microscopic ECE was present in 64 of the specimens (55%). There was no significant difference between DRE, prospective TRUS and retrospective TRUS in the overall accuracy of detection of ECE. However, when the results of DRE and TRUS were combined (if either was positive the result was considered positive), the positive predictive value (PPV) was 79% and the sensitivity (91%), with the overall accuracy increased significantly (P < 0.05). CONCLUSION: The presence and precise location of microscopic ECE can be determined pre-operatively with reasonable accuracy using real-time ultrasound combined with the results of DRE.

Aged↗
PubMed1994

Staging accuracy of magnetic resonance imaging versus transrectal ultrasound in stages A and B prostatic cancer.

The present study was undertaken to compare the ability of magnetic resonance imaging (MRI) and transrectal ultrasound (TRUS) to identify the presence or absence of extracapsular tumor extension and seminal vesicle involvement in patients with clinically localized (stages A and B, T1-T2) prostatic cancer. Sixty-four patients (ages 44-77 years) underwent radical retropubic prostatectomy and pelvic lymphadenectomy after staging with both MRI and TRUS. Surgical specimens were step-sectioned and examined at multiple levels. Radiographic staging was correlated with pathological staging. Both MRI and TRUS demonstrated better staging accuracy than conventional digital rectal examination [42% for digital rectal examination (DRE), 63% by TRUS, and 67% by MRI], although they suffered from understaging (31% by TRUS and 22% by MRI). The positive predictive value (PPV) for stage B disease was disappointingly low (42% for DRE, 53% for TRUS and 59% for MRI). However, the PPV for stage C disease was higher (81% for TRUS and 77% for MRI). In the evaluation of extracapsular invasion, the PPV of TRUS (81%) was higher than that of MRI (77%). The negative predictive value (NPV), however, for both TRUS and MRI was low (58 and 56%, respectively). In the evaluation of seminal vesicle invasion, both TRUS and MRI demonstrated poor PPV (50 and 40%, respectively), but the NPV was excellent (90% for TRUS and 96% for MRI). MRI failed to detect metastatic lymph nodes in 4 of 6 patients while falsely predicting their presence in 4 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Capillary leak syndrome likely the result of granulocyte colony-stimulating factor after high-dose chemotherapy.

Two cases of malignant lymphoma complicated with capillary leak syndrome following super high-dose chemotherapy and administration of granulocyte colony-stimulating factor (G-CSF) are presented. Subsequent to the nadir of granulocytes, and at the stage of rapid increase of granulocytes, the symptoms of fever, hypotension, dyspnea, pleural effusion and edema appeared, and laboratory data revealed hypoxia, hypocapnia and hypoalbuminemia. In addition, an abscess-like lesion was observed in the liver in one patient. After the administration of G-CSF was ceased or decreased, and pulse therapy with methylprednisolone was initiated, these symptoms disappeared quickly.

Adult↗
PubMed1994

Fatal aplastic anemia caused by Epstein-Barr virus infection after autologous bone marrow transplantation for non-Hodgkin malignant lymphoma.

We report a case of severe and fatal aplastic anemia during an episode of infectious mononucleosis caused by Epstein-Barr (EB) virus infection. The 13-year-old female patient had shown normal hematological findings and had previously undergone repeated chemotherapy and autologous bone marrow transplantation for refractory non-Hodgkin malignant lymphoma (NHL). She was probably in an immuno-suppressed condition prior to this episode of infection. The possible causal relationship of the EB virus infection in the pathogenesis of aplastic anemia was documented by the clinical course, demonstration of EB virus genome in the bone marrow cells, and an elevated plasma interferon (IFN)-gamma level.

Adolescent↗
PubMed1994

Hepatitis C virus infection and liver disease after allogeneic bone marrow transplantation.

We tested the sera of 29 patients treated with allogeneic bone marrow transplantation (BMT) by first- and second-generation ELISAs for hepatitis C virus (HCV) antibodies to study the effect of HCV infection on post-transplant liver diseases. Before BMT the first-generation assay detected anti-HCV in 3 of 29 patients (10%) and the second-generation assay detected anti-HCV in 5 of 29 (17%). After BMT the first-generation assay detected anti-HCV in 11 of 20 patients (55%) and the second-generation assay detected anti-HCV in 14 of 20 (70%). According to pre-transplant anti-HCV status by the second-generation assay, liver failure occurred in none of the anti-HCV-positive group and three of the anti-HCV-negative group. Graft-versus-host disease was responsible for liver failure in these patients. According to the post-transplant anti-HCV status by the second-generation assay, chronic hepatitis was found in 14 of 14 (100%) anti-HCV-positive and 1 of 6 (17%) anti-HCV-negative patients during post-transplant follow-up (p < 0.001). Post-transplant seroconversion from anti-HCV-negative to anti-HCV-positive status assay was detected by the second-generation assay in 9 of 20 (45%) patients. A biochemical deterioration during seroconversion was observed in 7 of 9 (79%) cases. HCV plays an important role in the etiology of post-transplant liver disease.

Adolescent↗
PubMed1994

[Home therapy approach in cancer patients-chemotherapy (case 2-3)--intra-arterial infusion cancer chemotherapy for hepatic metastasis of colorectal cancer--case report].

The development of interventional radiology and the like has made it possible to reduce the invasion and expand the applicability of intra-arterial infusion chemotherapy for unresectable cancer. By employing such methods and combining chemoembolization with continuous intra-arterial infusion chemotherapy, an response rate of 64% has been achieved in cases of unresectable hepatic metastases of colon cancer. These successful cases were reported along with personal comments by the authors.

Adenocarcinoma↗
PubMed1994

X-ray-induced cell death: apoptosis and necrosis.

X-ray-induced cell death in MOLT-4N1, a subclone of MOLT-4 cells, and M10 cells was studied with respect to their modes of cell death, apoptosis and necrosis. MOLT-4N1 cells showed radiosensitivity similar to that of M10 cells, a radiosensitive mutant of L5178Y, as determined by the colony formation assay. Analysis of cell size demonstrated that MOLT-4N1 cells increased in size at an early stage after irradiation and then decreased to a size smaller than that of control cells, whereas the size of irradiated M10 cells increased continuously. Apoptosis detected by morphological changes and DNA ladder formation (the cleavage of DNA into oligonucleosomal fragments) occurred in X-irradiated MOLT-4N1 cells but not in M10 cells. Pulsed-field gel electrophoresis showed that the ladder formation involved an intermediate-sized DNA (about 20 kbp). Most of the DNA was detected at the origin in both methods of electrophoresis in the case of M10 cells, though a trace amount of ladder formation was observed. Heat treatment of M10 cells induced apoptosis within 30 min after treatment, in contrast to MOLT-4N1 cells. The results suggest that apoptosis and necrosis are induced by X rays in a manner which is dependent on the cell line irrespective of the capability of the cells to develop apoptosis. DNA fragmentation was the earliest change observed in the development of apoptosis.

Animals↗
PubMed1994

[The expression and the role of vascular endothelial growth factor (VEGF) in human normal and myocardial infarcted heart].

Coronary collateral vessels reduce the damage of ischemic myocardium after coronary obstruction. Recently, vascular endothelial growth factor (VEGF) has been shown to increase vascular permeability and enhance the endothelial cell growth, leading to neoangiogenesis. VEGF has been reported to be upregulated in some neoplasms with endothelial proliferation, such as glioblastoma and vascularised adenocarcinoma. However, the expression and role of VEGF in human heart and those in its diseased condition have not been investigated. To elucidate its pathophysiological role, we studied the transcription and distribution of VEGF mRNA in normal human and myocardial infarcted hearts. Samples were obtained from 15 autopsy cases with and without ischemic heart disease. VEGF mRNA transcription was examined by using RT-PCR and Southern blot analysis. In all cases VEGF mRNA was detected in atrias, ventricles and valves. The amounts of each VEGF subtypes in cardiomyocytes were different from those in valves. By in situ hybridization method, VEGF mRNA was found in cytoplasm of normal cardiomyocyte but not in the vessels. However, in the cases of acute myocardial infarction, VEGF mRNA was detected in vascular smooth muscle cells of arterioles around the coagulation necrosis of the infarction as well as in mononuclear cells which infiltrated in the granulation tissues. In contrast, VEGF mRNA signals in cardiomyocyte around the necrosis were as much as those in the normal cardiomyocyte in non-diseased areas. By immunohistochemical studies, the mononuclear cells were supposed to be macrophages. This study suggests that VEGF could play an important role in neovascularization in acute myocardial infarction, and suggests that VEGF may have some favorable effect on infarcted myocardium.

Aged↗
PubMed1994

[A case of liver metastasis of leiomyosarcoma of residual stomach successfully treated by TAE and intra-hepato-arterial chemotherapy with infusion-a-port with administration of epirubicin].

A 60-year-old man who had a partial gastrectomy for gastric cancer 10 years ago was referred to our hospital for further examination for liver tumor. He was diagnosed as leiomyosarcoma of residual stomach associated with liver metastases. After preoperative transarterial embolization (TAE) with epirubicin of the anterior branch of right hepatic artery, residual stomach was resected, and the reservoir catheter and infusion arterial port were implanted. He was treated by intra-hepato-arterial chemotherapy of epirubicin. The patient has remained well for 2 years and 3 months without apparent complications.

Embolization, Therapeutic↗
PubMed1994

Clavicular approach to intraosseous infusion in adults.

We attempted a clavicular approach to intraosseous infusion (clavicular IO) as a new procedure in adults, and compared the flow rates of subclavian venous infusion, and clavicular, iliac and tibial IO. Furthermore, we observed enhanced roentgenograms of each IO by contrast media. As a result, clavicular IO indicated 11.9 +/- 0.68 mL/kg/hr (mean +/- SD, n = 29), iliac IO 32.2 +/- 4.48 (n = 21), tibial IO 18.9 +/- 1.28 (n = 15), and subclavian venous infusion 15.2 +/- 1.48 (n = 15). There were no statistically significant differences between subclavian venous infusion and clavicular IO. In roentgenograms, the contrast media entered the inferior vena cava from iliac IO, and via the femoral vein by tibial IO. The superior vena cava was enhanced through the subclavian vein in clavicular IO. No complications such as fractures or transclavicular penetrations by the IO needle occurred. In conclusion, clavicular IO may be an alternative infusion technique to provide the fluids into the subclavian vein in adults.

Aged↗
PubMed1993

Expression cloning of complementary DNA encoding three distinct isoforms of guinea pig Fc receptor for IgG1 and IgG2.

Three cDNA clones encoding the guinea pig Fc receptor for IgG1 and IgG2 (Fc gamma 1/gamma 2 R) have been isolated by an expression cloning strategy using mAb directed against the receptor. When transfected into COS-7 cells, these cDNA induced cell surface expression of the receptor that bound IgG1 and IgG2 antibodies complexed with the Ag. The ligand-binding affinities of these receptors were indistinguishable. Nucleotide sequencing has indicated that one of these clones, Fc gamma 1/gamma 2R-B1, is identical to the previously isolated cDNA clone homologous to the b2 isoform of human Fc gamma RIIB and that of murine Fc gamma RII, encoding a transmembrane glycoprotein containing two Ig-like extracellular domains. Two other clones, Fc gamma 1/gamma 2R-B2 and -B3, are identical to Fc gamma 1/gamma 2R-B1 except for an inframe insertion in the cytoplasmic region. The 48-nucleotide insertion found in Fc gamma 1/gamma 2R-B2 is identical to the first 48 nucleotides of the B3 insert that comprises 132 bp. Based on the size and homology of the inserted sequence, Fc gamma 1/gamma 2R-B2 and -B3 are identified as the homologues of the b1 isoform of human Fc gamma RIIB and that of murine Fc gamma RII, respectively. Reverse transcription and polymerase chain reaction of RNA revealed that macrophages and polymorphonuclear leukocytes expressed preferentially Fc gamma 1/gamma 2R-B1. On the other hand, B lymphocytes expressed all three forms, among which Fc gamma 1/gamma 2R-B2 and -B3 were selectively expressed in LPS-activated B lymphocytes that showed a dramatic increase in the levels of cell surface expression of Fc gamma 1/gamma 2R. These results suggest that the inserted sequences of Fc gamma 1/gamma 2R-B2 and -B3 are important to generate responses specific for B lymphocytes, which may include regulation of cell activation.

Amino Acid Sequence↗
PubMed1993

Endogenous circadian rhythmicity of somatostatin like-immunoreactivity in the rat suprachiasmatic nucleus.

The suprachiasmatic nucleus (SCN) of the hypothalamus has been established as the locus of the circadian pacemaker in mammals. The SCN is histochemically divided into two subdivisions: dorsomedial and ventrolateral subfields. The dorsomedial SCN is characterized, in part, by dense somatostatin-like immunoreactivity (SS-LI), but its functional significance in circadian pacemaking remains unclear. Our previous study revealed that 24 h SS-LI contents of the SCN in rats kept under light-dark (LD) conditions or blinded by orbital enucleation showed a distinct circadian rhythm. In the present study, 24 h SS-LI contents of the SCN in sighted rats kept under constant darkness (DD) conditions for prolonged periods were measured by enzyme immunoassay. Cellular contents of SS-LI exhibited a clear circadian rhythm on the third day of constant darkness (DD) with a peak at circadian time (CT) 5, corresponding to the time of peak levels found in LD conditions and in enucleated animals. This endogenous free-running rhythm continued to oscillate without attenuation of the amplitude even at 14 days in constant darkness. Moreover, SS-LI rhythm was found to be similar to the vasopressin rhythm in the SCN. In summary, these findings further strengthen the idea that the cellular content of SS-LI in the SCN is under the control of the endogenous circadian pacemaker.

Animals↗
PubMed1993

Effect of some constituents of chicken egg yolk lipoprotein on the growth and IgM production of human-human hybridoma cells and other human-derived cells.

Chicken egg yolk lipoprotein (YLP) was partially fractionated into some constituents, and the effect of constituents of YLP were examined on the growth and immunoglobulin (IgM and IgG) secretion of a HB4C5 human-human hybridoma cell line cultured in serum-free medium. Among the fractions, YP-1 and YP-2 fractions (LDL-rich fractions) were found to enhance the growth and IgM secretion of HB4C5 cells. The promoting activity was found in the commercial LDL. The lipid fraction in YP-2 fraction conjugated with 2-maltosyl-a-cyclodextrin was found to enhance the growth and IgM secretion of HB4C5 cells. Livetin-rich YP-3 and YP-4 fractions had no significant promoting activity. Commercial gamma-livetin and phosphatidyl choline possessed no growth-promoting activity. Phosphatidyl choline enhanced the IgM secretion of HB4C5 cells.

Animals↗