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Biomedical subjects

H Abe

Publications and source records attributed to H Abe.

At least 397 records · Page 22Linked to original sources
PubMed1998

Inflammatory cytokine production in whole blood modified by liposome-encapsulated hemoglobin.

The effect of Neo Red Cells (NRC), liposome-encapsulated hemoglobin, on production of tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) were studied in whole blood preparations ex vivo. Venous blood was collected with heparin and incubated in a CO2 incubator. Treatment of blood samples with NRC reduced the constitutive levels of TNF-alpha and IL-6. Lipopolysaccharide (LPS) treatment for 24 h increased production of TNF-alpha and IL-6 in a dose-dependent manner. Pretreatment with NRC (5%) for 24 h markedly potentiated the LPS-induced TNF-alpha production and, that of IL-6 to a lesser extent. Northern blotting analysis of total RNA in whole blood showed that pretreatment with NRC caused a marked increase in TNF-alpha mRNA expression in response to LPS. It is concluded that NRC potentiates LPS-induced TNF-alpha and IL-6 production in whole blood ex vivo, and that the potentiating effect of NRC on LPS-induced TNF-alpha production can be attributed, at least in part, to an increase in its mRNA expression.

Adult↗
PubMed1998

[Significance of pontine high signal intensity lesions on magnetic resonance imaging in patients with cerebral infarction].

We reviewed MRI findings in a series of 211 patients with cerebral infarction. A high signal in the basis pontis bilaterally in T2 weighted images (Central Pontine Hyperintensity, CPH), with almost-normal T1 weighted images, was present in 29 cases (12.9%). CPH findings were present more frequently in elderly patients, and were significantly associated with a previous history of cerebrovascular accident, although not with other arteriosclerotic risk factors. In patients with CPH. periventricular hyperintensity was severe and the number of infarctions of the thalamus was higher. These results suggest that a) CPH may arise from ischemia in subcortical areas or in the territory of the vertebrobasilar system, and that b) chronic brain ischemia, which may be partially due to aging, may play a more important role in cerebral infarction than the usual arteriosclerotic risk factors.

Adult↗
PubMed1998

Induction chemotherapy followed by reduced-volume radiation therapy for newly diagnosed central nervous system germinoma.

OBJECT: Although curative, radiation, which is conventionally administered for germinomas, causes significant neurological sequelae. This study aimed at reducing the volume and dose of radiation to a localized level of 24 Gy by pretreating the patient with chemotherapy. METHODS: Seventeen patients were divided into two risk groups based on serological findings and the extent of tumor. They were treated with chemotherapy prior to receiving localized radiation therapy. Six patients with solitary pure germinomas were treated with three or four cycles of cisplatin and etoposide (EP regimen) followed by 24-Gy local radiation therapy. Eleven patients with human chorionic gonadotropin (HCG)-secreting, multifocal, or disseminated germinomas received four to five cycles of ifosfamide, cisplatin, and etoposide (ICE regimen) followed by 24-Gy local radiation therapy. Craniospinal ports were used only in three cases of germinomas with dissemination. Gross-total resection was performed in three patients. Fourteen patients were able to be evaluated for their responses to chemotherapy. All patients achieved a complete response within three cycles. At a median follow-up duration of 24 months, 16 patients (94%) were alive without recurrence. One patient with an HCG-secreting germinoma experienced recurrence 38 months after surgery. That patient underwent successful salvage therapy using the same protocol. Thus, all 17 patients became free of disease with a 70 to 100% Karnofsky Performance Scale status. Toxicities associated with this study's chemotherapy regimen were mostly transient. No patient showed neurological or endocrinological deterioration during the follow-up period. CONCLUSIONS: The EP and ICE regimens were highly effective in treating the central nervous system germinomas and permitted dose and volume reduction of the radiotherapy. Localized 24-Gy irradiation was sufficient for disease control.

Adolescent↗
PubMed1998

Magnetic resonance imaging findings in ossification of the posterior longitudinal ligament of the cervical spine.

OBJECT: Because of the lack of magnetic resonance (MR) signal from cortical bones, MR imaging is inadequate for diagnosing ossified lesions in the spinal canal. However, MR imaging provides important information on spinal cord morphology and associated soft-tissue abnormality. The purpose of this study is to determine the role of MR imaging in the diagnosis and treatment of patients with ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. METHODS: The authors reviewed MR imaging findings in 42 patients with cervical OPLL who were examined with a superconducting MR imaging system. The types of OPLL reviewed included eight cases of continuous, 21 cases of segmental, and 13 cases of the mixed type. All patients were treated surgically either by anterior (26 cases) or posterior decompression (16 cases). CONCLUSIONS: The T1-weighted images clearly demonstrated the spinal cord deformity caused by OPLL. Associated disc protrusion was found to be present at the maximum compression level in 60% of the patients in this series. The highest incidence of disc protrusion (81%) was found in patients with segmental OPLL. Intramedullary hyperintensity on T2*-weighted imaging was noted in 18 patients (43%). The neurological deficits observed in these 18 patients were significantly more severe than those observed in the other 24 patients. Postoperative MR imaging revealed improvement in the spinal cord deformity, although the intramedullary hyperintensity was still observed in most cases. The present study demonstrates the importance of associated disc protrusion in the development of myelopathy in patients with cervical OPLL. Magnetic resonance imaging findings may be used to help determine the actual levels of spinal cord compression and to suggest the method of surgical treatment.

Adult↗
PubMed1998

[Study on the relationship between vascular invasion and prognosis in patients with locally confined renal cell carcinoma].

BACKGROUND: There exists controversy concerning the relationship between the vascular invasion and the prognosis in the locally confined renal cell carcinoma (RCC). We have tried to study on the relationship between the vascular invasion and the prognosis in these patients. METHODS: Of the five hundred and forty-eight patients with RCC who did not have lymph node and distant metastasis, the 464 patients without having the micro- and/or macro-vascular invasion (tumour thrombus) were analysed as the control, and the remaining 85 with micro- and/or macro-vascular invasion were subject to this study. RESULTS: There observed a significantly favourable prognosis in the patients with RCC who did not have the vascular invasion (pV0) compared with the patients who had the vascular invasion (pV1a: n = 43, P = 0.00068, pV1b: n = 34, 0 < P < 0.00006, pV2: n = 8, P = 0.012). Furthermore, the patients with pV1a showed a significantly favourable prognosis compared with the patients with pV1b (p = 0.00032), and the patients with pV2 (0 < P < 0.00006), and the patients with pV1b (P = 0.00032), and the patients with pV2 (0 < P < 0.00006), and the patients with pV1b also showed a significantly favourable prognosis compared with the patients with pV2 (0 < P < 0.0006). As to the relationship between the tumour size and vascular invasion (V-stage) the tumour size got larger along with the elevation of the V-stage, and there also observed a significant difference of the tumour size between the patients with pV10 and pV1a (P = 0.00578), with pV0 and pV1b (0 < P < 0.000061) and pV0 and pV2 (P = 0.0002). The same result was obtained in the relationship between the localization of the tumour and prognosis, i.e., the patients with pV2 showed a higher frequency of larger occupation of the tumour within the kidney compared with other V-stage patients. Regarding the recurrence rate, there observed a tendency toward high frequency of recurrence along with the elevation of V-stage. Furthermore, there observed an untoward relationship between the elevation of the V-stage and the periods of recurrence after nephrectomy. In an effort to analyse the disease-free survival, there observed a significant difference among the patients with pV0, pV1a, pV1b and pV2. CONCLUSION: We conclude that the vascular invasion is a very important prognostic factor in the patients with locally confined RCC. Furthermore, along with the elevation of the V-stage, it directly reflects the poorer prognosis.

Carcinoma, Renal Cell↗
PubMed1998

[A case of multiple organ failure with massive intestinal bleeding caused by methicillin-resistant Staphylococcus aureus in a postcystectomy patient--efficacy of mask continuous positive airway pressure training and intraarterial embolization].

A 51-year-old man underwent radical cystectomy with tubeless cutaneous ureterostomy. Methicillin-resistant Staphylococcus aureus (MRSA) enteritis developed postoperatively. MRSA caused critical infections such as pneumonia and sepsis, which subsequently progressed to adult respiratory distress syndrome, massive melena and multiple organ failure. The patient was rescued by intensive management including mask continuous positive airway pressure, systemic vancomycin administration and intraarterial embolization to stop jejunal bleeding.

Carcinoma, Transitional Cell↗
PubMed1998

Relationship between area under the concentration versus time curve of cyclosporin A, creatinine clearance, hematocrit value, and other clinical factors in Japanese renal transplant patients.

We evaluated the relationship between the area under the concentration versus time curve (AUC) of cyclosporin A (CsA) and several other clinical factors, because the clinical utility of AUC monitoring has been ambiguous. Fifty-four clinical time courses from 14 Japanese renal transplant patients during hospitalization, in the period from April 1990 to March 1997, were examined. In a bivariate regression analysis there was no correlation between the AUC and the daily dose of CsA (mg/kg/day) when the individual data or total series data were analyzed. In a chi-square test, the donor type of kidney (chi(2) = 25.254, df = 1, p = 0.0000) and renal function-related episodes, i.e. acute tubular necrosis, hemodialysis, hypertension, nephrotoxicity, or rejection (chi(2) = 13.982, df = 1, p = 0.0002) directly affected posttransplant renal function assessed by creatinine clearance, while episodes of hepatic function as assessed by the glutamate-pyruvate transaminase (GPT) activity level had no correlation with the posttransplant renal function evaluated according to creatinine clearance. In contrast, the renal function-related episodes significantly affected the AUC after renal transplantation (chi(2) = 4.934, df = 1, p = 0.0263), while hepatic function assessed by GPT did not. In a multivariate analysis, the creatinine clearance and obesity had significant positive correlations with the AUC, whereas the hematocrit had a significant negative correlation with the AUC. From these observations, we concluded that the dosage adjustment of CsA cannot be performed using the linear relationship between the daily oral dose and the AUC, and that renal function, obesity, and the CsA blood distribution properties affect the CsA pharmacokinetics after renal transplantation. Posttransplant renal function as well as obesity and CsA blood distribution properties are important factors to be considered when therapeutic monitoring is performed.

Adult↗
PubMed1998

[Experimental glaucoma model in the rat with laser trabecular photocoagulation after intracameral injection of India ink].

We tried to create an experimental glaucoma which is simple and highly reproducible in rodents. India ink was injected into the anterior chamber with a 30-gauge needle. The carbon particles were trapped in the chamber angle and formed a black band along the corneal limbus one week later. This area was then photocoagulated anteroposteriorly with an argon laser. Photocoagulation was repeated until the intraocular pressure was elevated to 25 mmHg or more by pneumotonometry performed at a one-week interval. The above procedure was applied to one eye of 7 rats with the fellow eye serving as control. Chronic elevation of intraocular pressure was obtained in all the 7 treated eyes. The eyes were then enucleated and examined by light microscopy. Carbon particles were phagocytosed by macrophages in the intertrabecular spaces. Peripheral anterior synechias were also present. The optic nerve-head showed remarkable decrease in nerve fibers and cavernous degeneration suggestive of glaucomatous optic nerve damage. This experimental model promises to be of value in further studies of glaucomatous optic nerve damage.

Animals↗
PubMed1998

[Influences of trabeculectomy combined with the use of mitomycin C on corneal endothelial cells].

We used a specular microscope to evaluate the corneal endothelial cells in 119 eyes before and 2 to 3 weeks after trabeculectomy with topical mitomycin C. The endothelial cell density per square millimeter averaged 2,569 +/- 487 (mean +/- standard deviation) before surgery and 2,444 +/- 536 after surgery, showing a decrease of 4.98%. The hexagonality decreased by 1.7%, the coefficient of variation increased by 1.9, and the average cell area increased by 6.82%. There were no statistical differences as a whole in these values. Decrease in hexagonality was more frequent in eyes with prior intraocular or glaucoma surgery. Eyes treated by laser trabeculoplasty showed a decrease in endothelial cell density, an increase in coefficient of variation and an increase in hexagonality. Eyes with postoperative flat anterior chamber showed significant changes in each parameter. The findings show that trabeculectomy with topical mitomycin C does not significantly affect the corneal endothelial cells at 2 to 3 weeks after surgery.

Administration, Topical↗
PubMed1998

[Relationship between age and thickness of the retinal nerve fiber layer in normal subjects].

We measured the thickness of retinal never fiber layer (RNFLT) in the peripapillary area in 120 eyes of 60 normal subjects. We used a scanning laser polarimeter, or Never Fiver Analyzer (NFA) by Laser Diagnostic Technologies, USA. Measurements were made along the peripapillary ring with the diameter of 1.75 disc diameter (DD) and another one 0.8 mm away from the disc margin. The RNFLT was not significantly correlated with age along The two rings. The RNFLT ratio of total/nasal area significantly decreased with increase in age. There was an increase in the difference of RNFLT between both eyes with increase in age in spite of considerable interindividual variations. The RNFLT values along both rings thus showed age-related changes in normal subjects.

Adult↗
PubMed1998

[Cervical epidural hematoma caused by cervical twisting after epidural anesthesia: a case report].

A case of cervical epidural hematoma caused by cervical twisting after epidural anesthesia was reported. A 41-year-old man who had had anterior fusion of C5 - 7 using a plate due to cervical spondylosis fifteen months before admission, had undergone epidural anesthesia through the C7/T1 interspace without difficulty for shoulder pain in a pain clinic. Two hours after injection, he complained of severe pain in his neck and both shoulders just after cervical twisting as was his custom. Within minutes he noted paresis of his left extremities. Neurological examination on admission revealed left side dominant tetraparesis and loss of pain and temperature sensations below the level of T4 on his right side. Laboratory data analysis and coagulation tests were normal. CT scans and MRI demonstrated an epidural hematoma with a small amount of air extending from C3 to the upper margin of C7. Four hours after the onset, a laminoplasty was performed from C3 to C7 with total removal of the hematoma. No bleeding site or any vascular abnormality was found to account for the hematoma formation. He was discharged with good recovery after operation. Most of the reported epidural hematomas associated with epidural anesthesia were related to coagulopathy, anticoagulant therapy or difficult puncture. On review of the literature, this is the first case of spinal epidural hematoma cause by cervical twisting after spinal anesthesia and which was without impaired coagulation or difficult spinal puncture. Cervical epidural hematoma should be considered as a possible complication in patients with pain or neurological deficits after some cervical manipulations.

Adult↗
PubMed1998

[Can EC-IC bypass prevent brain ischemia from recurring?].

The effectiveness of extracranial-intracranial arterial bypass (EC-IC bypass) surgery for patients with hemodynamic compromise still remains controversial. In the present study, we evaluated the correlation between the pre- and post-surgical cerebral hemodynamics and long-term prognosis. 28 patients and a subsequent 21 patients (41 men, eight women: mean age 59.9 [S.D. 8.6] years) with reduced cerebrovascular reserve due to steno-occlusive disease of the cerebral major arteries formed the study groups 1 and 2, respectively. Measurement of the mean hemispheric cerebral blood flow (mCBF) and the cerebral vasoreactivity (%mCVR) with an intravenous acetazolamide injection were performed by a 133Xe inhalation method and SPECT. Patients were treated with EC-IC bypass surgery and measurement of mCBF and %mCVR were made again about one month after surgery. The patients were observed for a long period (mean 44.3 months). During the follow-up period, 6 patients experienced recurrent ischemic strokes. The annual incidence of recurrent ischemic stroke was 4.4%. The patients with significantly reduced pre- and post-surgical resting mCBF of the affected hemisphere were at significantly higher risk of recurrent ischemic stroke than the patients with normal mCBF (p < 0.01). The %mCVR of the affected hemisphere rose after surgery.

Adult↗
PubMed1998

Multiple cerebral infarction in Japanese breath-hold divers: two case reports.

We report on two Japanese breath-hold divers (ama) who developed neurological disturbances following more than 3 hours of consecutive dives to 15-25 meters of seawater. Their magnetic resonance images of the brain showed multiple cerebral infarcts which were consistent with their neurological symptoms. The cerebral lesions seem to have been caused by repetitive breath-hold dives for extended periods of time. Immediate recompression is required when neurological symptoms develop after such dives.

Adult↗
PubMed1998

The organization of the thalamostriatal projection from the lateral posterior thalamic nuclear complex (LP) in the pigmented rat.

We investigated the thalamostriatal projection of the rat using biotinylated dextran amine (BDA) and wheat-germ agglutinin horseradish peroxidase (WGA-HRP). To obtain the patch/matrix compartments of the striatum (ST), we used mu-opioid receptor (MOR) immunoreaction labeling. Thus, an MOR-positive 'patch' was indicated by a darkly stained spot, while the MOR-negative 'matrix' was displayed as a non-immunoreactive region. A small injection of BDA was made in a subregion of the lateral posterior thalamic nucleus (LP). The LP-ST fibers originated in all subregions of LP and terminated in the dorsocaudal portion of ST, where the corticostriatal fibers from the visual cortex terminate (Serizawa et al. 1994). These LP-ST fibers and terminals were concentrated in the MOR-negative matrix compartment. Electron microscopic observations showed that the LP-ST terminals made asymmetrical synaptic contacts mainly (70%, n = 30) with the dendritic spines of the presumptive ST-output neurons, and fewer (30%) contacted dendritic shafts. The present results provide anatomical support for the contention that ST-output spiny neurons of the matrix that project to the pars reticulata of the substantia nigra or globus pallidus, may be influenced directly by the LP-ST projection.

Animals↗
PubMed1998

[Glaucoma with microcornea; morphometry and differential diagnosis].

To evaluate the characteristics of 10 glaucomatous cases with microcornea, we measured corneal diameter, curvature, axial length, and depth of anterior chamber, and examined the eyes with a specular microscope and an ultrasound biomicroscope. The ten cases examined in this study included 1 case of cornea plana, 2 cases of sclerocornea, 2 cases of nanophthalmos, and 5 cases of anterior microphthalmos. Three of the 10 cases were combined with open angle glaucoma, and the others with closed angle glaucoma. Open-angle glaucoma seemed like developmental glaucoma with angle maldevelopment. The closed angle type may appear at a younger age than in patients who have simple pupilary block. There are probably complex mechanisms related with closed angle glaucoma with microcornea. While differential diagnosis among these cases is relatively easy, we should evaluate how or why the intraocular pressure rises as far as possible before forming a treatment plan for each patient.

Adolescent↗
PubMed1997

Nitric oxide as a carcinogen: analysis by yeast functional assay of inactivating p53 mutations induced by nitric oxide.

We have used a yeast p53 functional assay to study induction of mutations in the p53 tumor suppressor gene by nitric oxide and cytosine methylation. The yeast assay identifies only biologically important p53 mutations. p53 cDNA was treated with the nitric oxide donor sydnonimine, PCR-amplified and transfected into yeast. Sydnonimine produced a significant, dose-dependent increase in C:G-->A:T transversions. Many important p53 mutational hotspots are postulated to arise by deamination of methylCpG in tumors. We therefore examined nitric oxide induction of mutations in p53 cDNA methylated by PCR-mediated substitution of 5-methylcytosine for cytosine or by treatment with the SssI CpG methylase. Both methylation procedures increased the baseline mutation rate, and nitric oxide treatment produced a further increase in mutation yield. Sequence analysis showed that methylation alone led to C:G-->T:A transitions, whereas nitric oxide treatment simply produced more C:G-->A:T transversions. Thus the most important factor in C:G-->T:A transition at CpG sites identified in this experimental system is cytosine methylation, consistent with spontaneous conversion of 5-methylcytosine to thymine by deamination.

Carcinogens↗
PubMed1997

Biologically inactive growth hormone caused by an amino acid substitution.

Short stature caused by biologically inactive growth hormone (GH) is characterized by lack of GH action despite high immunoassayable GH levels in serum and marked catch-up growth to exogenous GH administration. We found a heterozygous single-base substitution (A-->G) in exon 4 of the GH-1 gene of a girl with short stature, clinically suspected to indicate the presence of bioinactive GH and resulting in the substitution of glycine for aspartic acid at codon 112. We confirmed the presence of mutant GH in the serum using isoelectric focusing analysis. The locus of mutation D112G was found within site 2 of the GH molecule in binding with GH receptor (GHR)/GH binding protein (GHBP). The expressed recombinant mutant GH tended to form a 1:1 instead of the 1:2 GH-GHBP complex normally produced by wild-type GH. The formation of a 1:2 GH-GHBP complex is compatible with the dimerization of GHRs by GH, a crucial step in GH signal transduction. Mutant GH was less potent than wild-type GH not only in phosphorylation of tyrosine residues in GHR, janus kinase 2 (JAK2), and signal transducers and activators of transcription 5 (STAT5) in IM-9 cells, but also in metabolic responses of BaF/GM cells, a stable clone transfected with cDNA of the chimera of the extracellular domain of human GHR, the transmembrane and the cytoplasmic domain of the human thrombopoietin receptor. These results indicate that the D112G mutation in the GH-1 gene causes production of bioinactive GH, which prevents dimerization of GHR and is therefore responsible for the patient's short stature.

Child, Preschool↗