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Biomedical subjects

R Tanaka

Publications and source records attributed to R Tanaka.

At least 343 records · Page 19Linked to original sources
PubMed1995

Type 3 GM1 gangliosidosis: clinical and neuroradiological findings in an 11-year-old girl.

An 11-year-old Japanese girl was diagnosed as having type 3 GM1 gangliosidosis by clinical symptoms and enzyme assay. She was the youngest among the patients with type 3 GM1 gangliosidosis whose clinical and neuroradiological findings have been documented. Clumsiness since early infancy and dystonia since early childhood which progressed slowly without mental deterioration and dysmorphism led us to the diagnosis of type 3 GM1 gangliosidosis. Genotype determination showed point mutation in exon 2 of the beta-galactosidase gene, which is common among the patients reported in Japan. T2-weighted MRI demonstrated bilateral symmetrical hypointensity in the putamen and globus pallidus. Single photon emission computed tomography using 99mTc-HMPAO showed bilateral hyperperfusion in the basal ganglia which decreased gradually during 1 year of observation. Twenty-two patients with type 3 GM1 gangliosidosis reported in the literature whose onset was at under 15 years of age were reviewed.

Child↗
PubMed1995

Growth inhibition of human glioma cells modulated by retrovirus gene transfection with antisense IL-8.

The human glioma cell line, NP-1, expresses IL-8 mRNA and constitutively secretes IL-8 protein. Administration of recombinant IL-8 increased the proliferation of NP-1 cells in a dose-dependent manner. In the presence of anti-IL-8 antiserum, the IL-8 mediated proliferation of NP-1 cell growth was inhibited. Further, NP-1 cell growth was inhibited by transfection of retroviral constructs encoding antisense IL-8 both in vitro and in vivo models. These results suggest that antisense IL-8 gene therapy could be beneficial in gliomas where autocrine stimulation by IL-8 is implicated.

3T3 Cells↗
PubMed1995

Surgical experience with massive lobar haemorrhage caused by cerebral amyloid angiopathy.

Nineteen patients with massive lobar haemorrhage without angiographic lesions received direct or stereotactic surgery, and biopsy specimens were examined histologically. Ten patients (53%) were found to have vessels positive for Congo-red staining, and demonstrating amyloid angiopathy. In the patients with amyloid angiopathy, CT scan and surgical findings were investigated. Subarachnoid haemorrhage (9/10), irregularly shaped haematoma (9/10) and fluid-blood density level in the haematoma cavity (7/10) were frequently found on CT scan. The characteristic surgical findings in patients treated by direct surgery were subarachnoid haemorrhage adjacent to intracerebral haematoma (8/8) and the existence of a tangle of vessels in the haematoma cavity (4/8). Evacuation of haematomas was relatively easy, and difficulty of haemostasis was not encountered during surgery.

Aged↗
PubMed1995

Frequent TIA in the territory fed by the anastomosed STA after combined therapeutic ICA occlusion and extracranial-intracranial bypass: case report.

Frequent transient ischaemic attacks (TIAs) in the territory fed by the anastomosed superficial temporal artery (STA) after combined therapeutic internal carotid artery (ICA) occlusion and extracranial-intracranial bypass is described in a 52-year-old woman with a giant aneurysm in the supraclinoid portion of the left ICA showing impairment of visual acuity in the left eye and right upper quadrantanopia. After the balloon test occlusion of the left ICA which was tolerated, the left STA-middle cerebral artery anastomosis was performed and occlusion of the left ICA using detachable balloons was carried out a day later. TIAs corresponding to the territory fed by the anastomosed STA occurred nine times two to four days and five times eight to nine days after the ICA occlusion without new infarction on computed tomography (CT) scan. Single-photon emission computed tomography showed no hypoperfusion immediately after the initial TIA. CT scan revealed thrombosis of half of the aneurysm a day after the ICA occlusion. The patient developed the same TIA as previously by compression of the left anastomosed STA at the time of follow-up angiography which was carried out eight days after the occlusion. Although heparin was continuously administered after the ICA occlusion for two days, the initial TIA occurred during heparinization. Anticoagulation seemed to be inadequate judging from activated coagulation time and incomplete thrombosis of the aneurysm occurred during heparinization. It is likely that the TIAs are caused by embolism via the STA, which is a rare ischaemic complication.

Anastomosis, Surgical↗
PubMed1995

Elevation of serum creatine phosphokinase during growth hormone treatment in patients with multiple pituitary hormone deficiency.

Serum creatinine phosphokinase (s-CPK) increased to more than 500 U/l in 5 out of 21 patients with growth hormone (GH) deficiency during the 2 years of treatment with biosynthetic GH. In three of these five patients, s-CPK had elevated gradually after the start of GH treatment and remained high in one patient except in the period when GH injection was interrupted, and gradually decreased in the other two patients during treatment. These three patients had complete GH deficiency associated with multiple pituitary hormone deficiency due to pituitary stalk transection. One of the remaining two patients had Noonan syndrome and his s-CPK levels before therapy were relatively high. The fifth patient was a baseball athlete and the elevation of s-CPK seemed to be attributable to the strenuous exercise. Conclusion. s-CPK increases significantly in a certain group of patients with GH deficiency during GH replacement therapy. Measurement of s-CPK is to be included in the follow up laboratory tests at least in the 1st treatment year to evaluate the potential hazardous effects of GH on muscle.

Adolescent↗
PubMed1995

Use of acetylcholine (Ach) for spreading metaphase chromosomes and application to the cytogenetic analysis of human stomach cancers.

Cytogenetic studies of biopsy specimens endoscopically obtained from gastric cancers were performed in our laboratory. The necessity for well-spread chromosomes for analysis has resulted in the development of a new technique, in which culture medium containing acetylcholine (Ach) is used; with this new technique, the number of metaphases of analyzable karyotypes was significantly increased (P < 0.01 compared with a previous method in which Ach was not used). The mean ratio of metaphase numbers of analyzable karyotypes in four cases in which Ach was used was 38.1 +/- 8.1%, a value more than four times the number in the seven cases in which Ach was not used. It is possible that Ach may decrease the viscosity of the cytoplasm in gastric cancer cells by disrupting microfilaments.

Acetylcholine↗
PubMed1995

Rapid and gentle extraction, reconstitution and characterization of microfilament and glia filament from rat astrocytes.

We developed gentle and rapid methods for depolymerization and extraction of both microfilament and glia filament separately from a crude cytoskeletal fraction of rat astrocytes. Electron microscopy revealed that the filament reconstituted from the microfilament extract closely resembled F-actin that was formed from G-actin of rabbit skeletal muscle. It was found by immunoblotting analysis that even the reconstituted microfilament-like filaments, which had been purified by affinity chromatography with heavy meromyosin subfragment 1 (S1)-conjugated Sepharose, contained vimentin and glia fibrillary acidic protein (GFAP) besides actin, inferring the interaction between microfilament and glia filament. The filaments (9-10 nm thick) reconstituted from the glia filament extract were composed of actin and other minor components in addition to vimentin and GFAP. Actin, GFAP, 101, 34, 32.5, 30.5, 29.5 and 28 kDa proteins found in the reconstituted glia filament-like filaments were suggested to be glia filament-associated proteins.

Actin Cytoskeleton↗
PubMed1995

Internephron heterogeneity of growth factors and sclerosis--modulation of platelet-derived growth factor by angiotensin II.

We studied the early phase after 5/6 nephrectomy in Munich-Wistar rats to determine whether treatment with angiotensin II receptor antagonist (AIIRA) modulates the expression of platelet-derived growth factor (PDGF) mRNA and its protein among the glomeruli which are undergoing progressive hypertrophy and sclerosis. Average PDGF-B immunohistochemistry staining score (IHS, 0 to 3 scale) in glomeruli and PDGF-B chain mRNA from kidneys were both increased in 5/6 nephrectomy rats (N = 6) versus age-matched normal (N = 5) at week 4, when glomeruli were at early stages of sclerosis (IHS, 0.81 +/- 0.12 vs. 0.19 +/- 0.05; sclerosis index, S.I., 0 to 4 scale: 0.41 +/- 0.04 vs. 0.05 +/- 0.01, both P < 0.05). AIIRA (80 mg/liter drinking water, N = 6) started at time of 5/6 nephrectomy prevented the development of sclerosis (S.I. 0.08 +/- 0.03) and decreased PDGF-B protein (IHS 0.22 +/- 0.08, both P = NS vs. normal), and PDGF-B chain mRNA. In contrast, triple therapy (TRX; hydralazine, reserpine and hydrochlorothiazide, N = 5) in doses which controlled systemic blood pressure resulted in intermediate level of glomerulosclerosis at this early time point of progressive injury. Concurrently, TRX failed to affect the expression of PDGF-B protein (IHS 0.86 +/- 0.19) or its mRNA expression. The PDGF-B distribution was not uniform amongst the glomeruli with varying stages of sclerosis. There was a strong correlation in individual glomeruli of increased PDGF-B staining with early sclerotic changes (P < 0.01), with the disappearance of this correlation in glomeruli with advanced sclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗
PubMed1995

The effects of a carotid-jugular fistula on cerebral blood flow in the cat: an experimental study in the chronic period.

The purpose of the present study was to investigate the effects of feline carotid-jugular fistula (Spetzler's model) on cerebral blood flow at 8 weeks after creation of the fistula. Using laser-Doppler flowmetry, cortical cerebral blood flow (CBF) on the fistula side was measured in 10 cats, Occlusion of the fistula showed no cortical CBF changes in 6 animals, but transient increases in 4. CO2 reactivity in the closed fistula was preserved. No neurological or histological abnormalities were recognized. These findings suggested that cerebral hemodynamic changes due to Spetzler's CJ fistula model are minimal even in the chronic period after fistulization. Therefore, creation of another experimental arterio-venous fistula model is mandatory for the investigation of hemodynamic changes following resection of a cerebral arteriovenous malformation.

Animals↗
PubMed1995

Cytokine production in five tumor cell lines with activity to induce cancer cachexia syndrome in nude mice.

To identify the so-called toxohormone, which is a tumor-derived factor with activity to induce cancer cachexia syndrome in tumor-bearing animals, 5 human cancer cell lines with this activity were studied for cytokine production. Tumor cell products with activity to inhibit lipoprotein lipase (LPL) were shown to play an important role in the development of the cancer cachexia syndrome. All culture media conditioned by the 5 cell lines possessed LPL-inhibitory activity. However, the activity differed with the cell line. In order to characterize the activity, we examined whether the cultured cells produced cytokines with activity to inhibit LPL. A melanoma cell line, SEKI, and a neuroepithelioma cell line, NAGAI, were found to express a large amount of leukemia inhibitory factor (LIF) mRNA. Furthermore, both of these cell lines were demonstrated to produce a large amount of LIF protein, and plasma levels of LIF were extremely elevated in SEKI- and NAGAI-bearing nude mice, indicating that LIF produced by the tumor cells induced cancer cachexia syndrome in the animals. Thus, LIF fulfills the requirements for a toxohormone, except for suppressive activity on liver catalase. In contrast, the mechanisms responsible for cachexia in the MKN-1-, LX-1- and LS180-bearing mice remain unknown. These findings suggest that various types of bioactive substances produced by cancer cells could be toxohormones.

Animals↗
PubMed1995

Molecular and cytological characterization of a highly repeated DNA sequence in Raphanus sativus.

A highly repeated DNA sequence with a repeat unit of ca. 180 bp was found in genomic DNA HindIII-digests of Raphanus sativus. The repeating units of six isolated, independent clones were sequenced. These units have 177 or 178 bp, are 36% G+C in their DNA base composition, and show 90% sequence homology. The copy number of this 180-bp repeat unit is about 0.5 x 10(6) per diploid genome. In situ hybridization analysis with the repeating units as the probe and C-banding analysis indicated that the repeated DNA sequence of R. sativus is closely associated with the major C-heterochromatins in the proximal regions of all 18 chromosomes at mitotic metaphase.

Base Composition↗
PubMed1995

Inhibition of collagen cross-linking: effects on fibrillar collagen and ventricular diastolic function.

The fibrillar collagen network is postulated to be a primary determinant of left ventricular diastolic stiffness. This hypothesis was tested by examining the structural and physiological effects of a reduction in fibrillar collagen content and cross-linking in the intact left ventricle. Collagen cross-linking was inhibited by treating five normal adult pigs with beta-aminopropionitrile (BAPN; 10 g/day po) for 6 wk; five normal untreated pigs served as controls. Left ventricular volume, mass, and function were determined by simultaneous echocardiography and catheterization. Chamber stiffness, defined by pressure vs. volume data, and myocardial stiffness, defined by stress vs. dimension data, were determined from variably loaded beats during dextran infusion. Collagen distribution (% area) and integrity (% confluence) were determined by light microscopy. Collagen content was measured by hydroxyproline assay, and collagen cross-linking was measured by salt extraction. BAPN decreased collagen distribution (% area decreased from 12 +/- 1% in control to 7 +/- 1% in BAPN, P < 0.05), collagen integrity (% confluence decreased from 8 +/- 1% in control to 4 +/- 1% in BAPN, P < 0.05), collagen content (from 36 +/- 2 mg/g dry wt in control to 27 +/- 2 mg/g dry wt in BAPN, P < 0.05), and collagen cross-linking (extractable collagen increased from 21 +/- 2% in control to 28 +/- 2% in BAPN, P < 0.05). BAPN decreased chamber stiffness (0.13 +/- 0.02 in control to 0.06 +/- 0.01 in BAPN, P < 0.05) and myocardial stiffness (10.4 +/- 0.5 in control to 6.6 +/- 0.5 in BAPN, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aminopropionitrile↗
PubMed1995

Role of tryptase in immediate cutaneous responses in allergic sheep.

In this study, we used a specific tryptase inhibitor, APC-366 [N-(1-hydroxy-2-napthoyl)-L-arginyl-L- prolinamide hydrochloride] to investigate the effect of intradermally administered tryptase and tryptase released by antigen challenge on the immediate cutaneous reaction (ICR) in allergic sheep. The surface areas of cutaneous wheals produced by intradermal injections (0.05 ml) of 1 and 10 ng tryptase alone, tryptase combined with 3 U heparin (tryptase-heparin), or Ascaris suum antigen (10(-5) dilution) with or without pretreatment with APC-366 (1 mg/ml) were measured at 20 and 60 min after challenge. Intradermal injections of 1 and 10 ng tryptase alone (n = 7) produced an ICR of < or = 20% of that obtained after injection of histamine (5% wt/vol). Intradermal injection of tryptase-heparin (n = 7), however, resulted in 50 (1 ng) and 82% (10 ng) of the ICR to histamine (both, P < 0.05 vs. tryptase alone). APC-366 inhibited (P < 0.05) the ICR to 1 and 10 ng tryptase-heparin by > or = 70% at all times (n = 8) but had no effect on the histamine-induced ICR (n = 3). A combination of the histamine H1 antagonist chlorpheniramine (2 mg/kg iv) and the H2 antagonist metiamide (3 mg/kg iv) given 40 min before challenge (n = 8) inhibited the response to 1 and 10 ng tryptase-heparin by 42 and 62% at 20 min and by 96 and 86% at 60 min, respectively (all, P < 0.05). APC-366 also blocked the ICR to A. suum antigen by 68% (P < 0.05) in nine sheep. These results indicate that intradermal injection of tryptase-heparin can induce an ICR. This ICR can be inhibited by APC-366 or a combination of the histamine H1 and H2 antagonists, suggesting that the tryptase response is mediated by histamine. APC-366 also blocks the mast cell-mediated ICR to intradermally injected A. suum antigen. Collectively, these results suggest that tryptase may modulate mast cell histamine release.

Animals↗
PubMed1995

Use of continuous electrical capacitance and transepidermal water loss measurements for assessing barrier function in neonatal rat skin.

A vital function of the skin is to oppose the loss of water to the environment. In this study, two complementary methods, transepidermal water loss (TEWL) and continuous electrical capacitance under occlusion, were used to assess epidermal barrier function in a developmental animal model, the neonatal Sprague-Dawley rat. TEWL monitors barrier function directly while the increase in capacitance under occlusion is related to both the skin's barrier function and to its water holding capacity. Serial tape stripping of the stratum corneum on 1-day-old rat pups led to a significant increase in both TEWL and continuous capacitance measurements. Anatomic site heterogeneity and the effects of surface temperature were also studied. The ventral skin surface exhibited an increase in the continuous capacitance measurements, an effect possibly due to the thinner stratum corneum on the ventral side. Both TEWL and continuous capacitance values were directly correlated with ambient temperatures within the physiological range.

Animals↗
PubMed1995

Basic fibroblast growth factor increases regional cerebral blood flow and reduces infarct size after experimental ischemia in a rat model.

BACKGROUND AND PURPOSE: The aim of this study was to ascertain whether basic fibroblast growth factors (bFGF) caused reduction in size of cerebral infarcts in Sprague-Dawley rats with experimental ischemia. METHODS: In the first experiment we induced permanent occlusion of the left middle cerebral artery (MCA). Within 5 minutes after MCA occlusion, we infused bFGF (100 ng in 0.1 mL of saline) in the bFGF-treated group (n = 14) and 0.1 mL of saline alone in the control group (n = 7) into the common carotid artery ipsilateral to MCA occlusion. We harvested the brains 24 hours after MCA occlusion and determined infarct size planimetrically as a percentage of hemisphere size. In the second experiment cerebral blood flow (CBF) was continuously measured for 120 minutes after MCA occlusion in the bFGF-treated group (n = 9) and in the control group (n = 8) with the use of laser-Doppler flowmetry. RESULTS: Infarct size in the bFGF-treated group decreased significantly in comparison with that in the control group (repeated-measures ANOVA, P < .0001). CBF in the transitional areas between the MCA and the anterior cerebral artery significantly increased in the bFGF-treated group in comparison with that in the control group (repeated-measures ANOVA, P < .005). An approximate 58% decrease in infarct size and a 40% increase in regional CBF were seen on bFGF treatment. CONCLUSIONS: The present study suggested that intracarotid administration of bFGF (100 ng) can reduce infarct size after MCA occlusion. It was speculated that the increased CBF in the penumbral areas of MCA may contribute to contraction of infarct size.

Animals↗
PubMed1995

Primary angiitis of the central nervous system: report of two cases and review of the literature.

Two cases of primary angiitis of the central nervous system with subarachnoid hemorrhage are reported. One patient was admitted with very thin and localized sulcal subarachnoid hemorrhage, followed by the development of multiple parenchymal edema. Although the first angiography showed only a mild narrowing of an artery, the second angiography demonstrated multiple segmental narrowings of arteries. An open biopsy failed to show histological changes. The second patient suffered from sylvian subarachnoid hemorrhage along with multiple intracerebral hemorrhages, with angiography that was diagnostic for angiitis. In both cases, predonine was initiated and further angiography clearly demonstrated a resolution of the angiitis. The usefulness of serial angiography for diagnosis in comparison with surgical biopsy and for monitoring the treatment of this disease is discussed. The occurrence of subarachnoid hemorrhage in this disease is also reviewed.

Adult↗