Biomedical subjects

T Kuwabara

Publications and source records attributed to T Kuwabara.

At least 127 records · Page 7Linked to original sources

PubMed1991

Study on the erythrocytes from myotonic dystrophy with multi-nuclear NMR.

We have studied the water permeability through membranes, the function of the Na pump, and glucose metabolism of erythrocytes of patients with myotonic muscular dystrophy (MyD) using 1H--, 23Na, and 13C-NMR techniques. A significant decrease in water permeability was recognized in the MyD erythrocyte membrane, and impaired Na pumping was suspected to be correlated with the former biochemical abnormalities in band III protein of MyD erythrocyte membrane. Significant acceleration of glycolysis in the erythrocyte for the first 160 minutes was also recognized in MyD; however, the production of lactate showed no difference between MyD and controls. The increased glucose uptake in MyD may be compensatory to the diminished pumping mechanism, but further information, such as inorganic phosphate permeability and the activity of the rate-limiting enzyme of erythrocyte glycolysis, is needed.

Adolescent↗

PubMed1991

Telecanthal approach for meningiomas in the ethmoid and sphenoid sinuses.

In three cases involving meningiomas in the ethmoid and sphenoid sinuses, transbasal spreading of the interocular distance (telecanthal approach) was used for tumor removal and reconstruction of the skull base. This telecanthal approach involves 1) bilateral en bloc removal of the superior lateral rim of the orbit, the nasal bone, and the posterior lateral wall of the orbit; 2) detachment of the medial canthal ligaments; and 3) spreading of the interocular distance. This approach provides a wide working space beneath the anterior half of the midline skull base, and needs neither a facial incision nor significant retraction of the brain. The surgical technique and its modification are described. The discussion focuses not only on comparisons with other techniques, but on the indications for this approach. Meningiomas originating in the paranasal sinuses are rare; a brief review of the literature concerning the clinicopathological features and pathogenesis is also given.

Adult↗

PubMed1991

Immunoelectron microscopic evidence for organ differences in the composition of peroxisome-specific membrane polypeptides among three rat organs: liver, kidney, and small intestine.

We examined the distribution of peroxisome-specific membrane polypeptides (PMPs) among peroxisomes of the liver, renal cortex, and jejunal mucosa, using antibodies for 70 KD, 26 KD and 22 KD PMPs. Immunoblot analysis showed signals for 70 KD polypeptide in all three kinds of tissue, but for the other two only in the liver and renal cortex, with neither being detected in jejunal mucosa. The total amounts of PMPs increased in all three organs with DEHP (di-(2-ethylhexyl)phthalate) administration. By immunoelectron microscopic analysis using protein A-gold, the three PMPs were localized along the peroxisomal membrane. Quantitation of the gold particles associated with the peroxisomal membrane showed an increase in the density of 70 KD and 26 KD PMPs but a decrease in 22 KD PMP with the administration of DEHP. The presence of tissue-specific localizations of PMPs suggest the 70 KD PMP is a common constituent of peroxisomes of these three tissues, whereas 26 KD and 22 KD PMPs are absent in microperoxisomes of jejunal mucosal epithelium.

ATP-Binding Cassette Transporters↗

PubMed1991

Altered reactivity of hemolysate-treated cultured smooth-muscle cells from rabbit basilar artery determined by digital imaging microscopy.

During culture, smooth-muscle cells obtained from rabbit basilar arteries were examined for contractile activity by means of differential interference microscopy with a video analysis system (digital imaging microscopy system). This system proved useful for observing the contraction and ultrastructural changes of the living cells. Hemolysate-treated cells showed augmented responses to 5-hydroxytryptamine and leukotriene C4, but not to KCl. This augmented response diminished gradually during the culture period. Both a phospholipase C blocking agent, 2-nitro-4-carboxyphenyl-n,n-diphenylcarbamate (NCDC), and a myosin light chain kinase blocking agent, 1-(5-chloronaphthalenesulfonyl)-1H-hexahydro-1,4-diazepine (ML-9), suppressed this augmented response. Protein kinase C activity of the cells, as measured by Western blot analysis, did not increase during the period of culture with hemolysate. The results obtained suggest that hemolysate had the following effects on the cells: 1) acute but gradual contraction of the cells; 2) augmentation of cellular responses to vasoactive agents; and 3) progressive contraction and morphological alteration of the cells. Possible mechanisms by which hemolysate exerts these effects are discussed, taking into consideration the interrelationship between these effects.

Animals↗

PubMed1991

Numbers of cortical vitreous cells and onset of cataracts in Royal College of surgeons rats.

Royal College of Surgeons (RCS) rats have hereditary retinal degeneration with associated posterior subcapsular opacities. A link between light, retinal degeneration, and cataracts may consist in peroxidation of polyunsaturated fatty acids of rod outer segment lipids to yield water-soluble toxic aldehydes that can traverse the vitreous and react with bow cells and posterior lens fibers. In an immune reaction to the retinal degeneration, macrophages multiply in the retina and in the cortex of the vitreous. In dystrophics, the cortical vitreous separates readily from attachments to retina, ciliary body and lens, and from the vitreous gel. This web-like structure was stained and spread on a counting chamber. Cells were counted at 15-130 postnatal days in pink- and black-eyed RCS dystrophics and in congenic controls to correlate numbers of cells, temporal and geographic patterns of retinal degeneration, and onset of opacities. Rats were reared in cyclic light (10-40 lux inside the cage) and fed a natural ingredient diet (NIH-07). Cortical vitreous cells increased markedly in pink- and black-eyed dystrophics at 50-53 days when slit-lamp detectable opacities occurred in both. The increase was 4.6-fold in pink- and 2.3-fold in black-eyed rats compared with controls. At 50-53 days, the dystrophy affected all quadrants of the retina severely in pink-eyed RCS but only the inferior periphery in black-eyed RCS. Consequently, severe degeneration in one quadrant may suffice to initiate an opacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed1990

Molecular basis of mucopolysaccharidosis type VII: replacement of Ala619 in beta-glucuronidase with Val.

We have identified a mutation causing beta-glucuronidase (beta Gl) deficiency in a 6-year-old girl with mucopolysaccharidosis type VII. Enzyme assay of lysates of a girl's lymphocytes or cultured fibroblasts showed little residual activity and a normal beta Gl-specific mRNA level, as revealed by Northern-blot analysis. Sequencing of the full-length mutated cDNA revealed a C----T transition, an event causing a single Ala619----Val change (we designated this variant beta GGifu). This change is detected by loss of the cleavage site for the enzyme Fnu4HI in the mutated cDNA. On the basis of the loss of Fnu4HI restriction site, the patient was shown to be a homozygote with the beta GGifu mutation and her parents and brother were heterozygotes. This mutation disrupts a functional domain consisting of a region of sequence highly conserved among human, rat and bacterial beta Gls, and it reduces the enzyme activity, as tested by transfection of COS cells with expression vectors harboring the mutated cDNA.

Alanine↗

PubMed1990

Effect of recombinant human lipocortin I on brain oedema in a rat glioma model.

Glucocorticoids have been extensively used to treat brain oedema, but little is known on the mechanisms of steroids in the prevention and resolution of tumour-induced brain oedema. Recently, the mechanism of steroid action is thought to involve synthesis of proteins with antiphospholipase activity called lipocortins. In a previous study, we have demonstrated the efficacy of dexamethasone (DEX) in resolving peritumoural oedema in a rat glioma model. Using the same model, we studied the effect of recombinant human lipocortin I on the resolution of peritumoural oedema. Intracerebral tumours were produced in 6-week-old Wistar rats by implantation of rat glioma C6 cells. In comparison with sham-operated controls, the tumour-implanted animals showed significant increase in the cortical water content, which was reduced by DEX administration to the level in the sham-operated controls. The water content within the tumour was also significantly decreased by DEX treatment. On the other hand, there was no difference in water content between lipocortin-treated and non-treated animals. These findings suggest that tumour-induced brain oedema can be reduced by DEX treatment but not by lipocortin. In conclusion, it is doubtful whether glucocorticoids exert their action in resolving brain oedema by inducing PLA2 inhibitory proteins named lipocortins.

Animals↗

PubMed1990

Prevention of cataracts in pink-eyed RCS rats by dark rearing.

Royal College of Surgeons rats have hereditary retinal degeneration and associated posterior subcapsular opacities (PSO) of the lens, detectable by slitlamp at 7-8 postnatal weeks in both pink- and black-eyed rats. The retinal degeneration is intensified by light, especially in pink-eyed rats. A fourth of pink-eyed rats developed mature cataracts by 9-12 months of age, but black-eyed rats whose retinas are protected from light by pigmented irises and pigment epithelium rarely have mature cataracts (3% or less), indicating light may be a factor in cataractogenesis. Prior work had shown that dark rearing reduced the rate of retinal degeneration in pink- but not black-eyed rats, but cataracts were not studied. In the present work, pregnant pink-eyed females were placed in a darkroom 1 week before parturition. Pups were removed over intervals at 20-85 postnatal days for: (a) microscopic study of fresh lenses and of fixed, stained retina and lens, and (b) counts of cells mm-2 of the web-like vitreous cortex after it had been dissected free. The macrophage-like cells are a quantitative index of immune reaction to retinal damage. At 50-53 postnatal days, in pink-eyed cyclic light reared RCS, the mean number of macrophages was 4.6-fold that in congenic controls, but in those that were dark reared it was only 1.4-fold. This was less than the increase in cyclic light reared black-eyed RCS (2.3-fold that in congenic black-eyed controls). Total absence of light reduced retinal degeneration and the number of macrophages, and prevented PSO detectable microscopically.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

[Paraneoplastic retinopathy simulating cone dystrophy with achromatopsia].

A 72-year-old woman developed recurrent blindness on exposure to bright light (sunlight). Examination revealed total achromatopsia; bilateral central scotomas, predominant suppression of the cone response by electroretinography, and narrowing of the retinal arteries on ophthalmoscopy. The general examination revealed a pelvic tumor that later proved to be a pleomorphic carcinoma of presumed uterine origin. The patient died of metastatic disease 9 months after the ocular symptoms developed. Histopathologic examination of the eyes revealed loss of the photoreceptors, most extensive in the macular regions, and selective loss of the cones from the rest of the retinas. No ocular metastases of inflammation were found. The changes described are interpreted as paraneoplastic retinopathy of autoimmune origin.

Aged↗

PubMed1990

Hypothalamic obesity due to hydrocephalus caused by aqueductal stenosis.

A case is presented of 14 year old female with hypothalamic obesity due to hydrocephalus caused by aqueductal stenosis. Evidence of hypothalamic obesity included 1) acute hyperphagia and weight gain, 2) neuroradiology showed hydrocephalus with focal enlargement of the third ventricle, 3) endocrinological studies revealed hyperinsulinaemia and impaired growth hormone (GH) response to arginine, but normal GH response to growth hormone-releasing factor (GRF) and 4) Torkildsen's ventriculo-cisternal shunting resulted in improvement in hyperphagia and obesity.

Adolescent↗

PubMed1990

[Effects of lithium on mouse hematopoiesis].

Both in vitro and in vivo effects of lithium on mouse hematopoiesis were investigated. The addition of 1 mmol lithium carbonate to the culture enhanced in vitro colony formation of the granulocyte macrophage precursor (CFU-GM) by 26%, the megakaryocyte precursor (CFU-Meg) by 29%, and the erythrocyte precursor (CFU-E) by 46% as compared to the control culture without lithium carbonate. Lithium resulted in an increase of colony size for both the CFU-Meg and the CFU-E. Oral administration of lithium chloride at daily doses of 0.3 mg caused a significant increase in granulocytes 3 to 12 days after the start of administration. It also resulted in a mild elevation of the platelet count, but it had no influence on hematocrit. The number of the CFU-GM increased transiently on day 3 of the lithium administration and subsequently returned to the pretreatment level. Furthermore lithium accelerated the recovery of the granulocyte count and bone marrow CFU-GM content after 300 rad total body X ray irradiation.

Animals↗

PubMed1990

Microsurgical thromboendarterectomy of the cavernous carotid artery--case report and surgical technique.

A 53-year-old male suffered a transient right hemiparesis and left monocular blindness. Angiography revealed 80% stenosis of the cavernous carotid artery. Microsurgical thromboendarterectomy was performed by a direct approach through Parkinson's triangle. During surgery, the carotid circulation was transiently trapped between the cervical and the supraclinoid segment and the trapped arterial lumen was irrigated with heparinized saline. Soft elastic lesion was easily removed. Cavernous carotid thromboendarterectomy through a direct approach is considered as a suitable operation for the solitary and localized stenotic lesions of the cavernous carotid artery, although this operation has not yet been reported to date.

Carotid Artery Diseases↗

PubMed1990

Indications for surgical treatment of putaminal hemorrhage. Comparative study based on serial CT and time-course analysis.

Serial computerized tomography (CT) scans were correlated with a precise time-course analysis of the neurological condition of 180 patients with hypertensive putaminal hemorrhage. All patients entered the study within 3 hours of the ictus. In this series, 111 patients were treated conservatively and 69 surgically. The neurological condition of each patient was measured by means of a newly proposed grading system for intracerebral hemorrhage-intracranial hemorrhage (ICH grade) which is a modification of the Glasgow Coma Scale. Serial CT scans revealed that most hemorrhages were completed within 6 hours after ictus. Based on the ICH grade at 6 hours postictus, a clinical classification of the severity of putaminal hemorrhage was defined: fulminant, rapidly progressive, slowly progressive, and nonprogressive. According to this classification, precise time courses of the ICH grade were compared between the conservative and surgical treatment groups in a 7-day postictal period. Activities of daily living at 6 months after ictus were also compared. Surgical treatment for a rapidly progressive hemorrhage appears to be beneficial if undertaken in patients under 65 years of age. Surgery in a slowly progressive hemorrhage should be considered only in a small number of patients who deteriorate neurologically with conservative treatment. In this series of patients, surgical treatment of fulminant and nonprogressive hemorrhage was not likely to improve the quality of life or functional recovery. Regardless of treatment modality, CT provided evidence that patients with anterior capsular hemorrhage (16% in this series) showed good recovery of motor and speech function.

Activities of Daily Living↗

PubMed1990

A new intracranial Silastic encircling clip for hemostasis. Technical note.

A new encircling clip made of a silicone tube has been designed for treating accidentally injured cerebral vessels. No special holders are necessary. This clip can be tailored depending on the shape of the injured vessel. The clip is a simple and effective tool for achieving complete hemostasis.

Cerebral Arteries↗

PubMed1990

[The retroperitoneal rhabdomyosarcoma: a case report].

A case of rhabdomyosarcoma in the retroperitoneal space is reported. The patient, a 71-year-old man, visited us with a complaint of left flank pain. The tumor measuring 13 x 10 x 7 cm and weighing 700 g, was removed operatively. The patient had no evidence of recurrence in 12 months following surgery.

Aged↗

PubMed1990

[Management results of primary intracranial malignant lymphoma].

Nineteen cases of primary malignant lymphoma of the central nervous system were reported. The clinical characteristics, diagnostic procedure and therapeutic method, especially concerning chemotherapy, were analysed. The following conclusions were obtained: 1) histological classifications and surgical procedures were not factors involved in prognosis. 2) radiotherapy was regarded as an effective but a palliative treatment. 3) combined chemotherapy for systemic malignant lymphoma, such as VEMP, VEP, COPP, seemed to be of little use for intracranial malignant lymphoma. 4) intra-arterial administration of high-dose methotrexate, ACNU and intravenous administration of high-dose cytosine arabinoside can be expected to be a useful chemotherapeutic approach.

Adolescent↗

PubMed1990

[Treatment using CDDP and radiation therapy in treating bladder tumor].

Combination therapy consisting of cis-diamine-dichloroplatinum (CDDP) and radiotherapy was used to treat bladder cancer. The subjects were 20 patients with bladder cancer we experienced since September, 1986. They were between 33 and 83 years old and consisted of 13 males and 7 females. Among the histotypes and grades, there were 3 cases of G2, 7 of G2-G3 and 10 of G3 metastatic epithelial carcinoma. The classification of primary tumors was T2 in six cases, T3a in 12 cases and T4 in two cases. In 12 cases where the bladder was preserved, this therapy was performed after TUR biopsy or TUR, and the effects were evaluated after observation periods of 5-17 months. Side effects caused by CDDP were anorexia in 15 cases, nausea and vomiting in 10 cases, leukopenia in 10 cases and thrombocytopenia in four cases. Those caused by the radiotherapy were diarrhea in seven cases and skin disorders in six cases. All of these side effects were mild and the patients recovered spontaneously.

Adult↗

PubMed1990

[Successful treatment of adult T-cell leukemia with interferon-alpha-2b by systemic and local administration].

A 59 years old woman, born in Fukuoka Prefecture, was admitted to our hospital in Aug, 1988 because of diarrhea, fever and skin eruption. Physical examination revealed systemic lymphadenopathy and hepatosplenomegaly. The white blood cell count was 11,200/microliters with 28% atypical lymphocytes with convoluted nuclei. Mild anemia, thrombocytopenia and hypercalcemia were also observed. Antibody against the adult T-cell leukemia (ATL) associated antigen in serum was positive. OKT 4/8 ratio was high. A diagnosis of ATL was made. Because of the complications of pneumonia and herpes simplex, systemic chemotherapy was not given, and interferon (IFN)-alpha-2b was intramuscularly injected daily from Oct, 1988, resulting in the disappearance of atypical lymphocytes and improvement of skin lesions. The effect of IFN therapy lasted for three months, followed by increase of atypical lymphocytes. Although the patient became refractory to systemic IFN therapy, local injection of IFN into a buccal tumor infiltrated with atypical lymphocytes resulted in its regression of size. In spite of continued administration of IFN, the patient died of pneumonia in Jan, 1989.

Female↗