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Biomedical subjects

M Abe

Publications and source records attributed to M Abe.

At least 145 records · Page 8Linked to original sources
PubMed2001

TGF-beta attenuates the transactivation activity of Ets-1 despite its induction via the inhibition of DNA binding.

We examined whether TGF-fl affects the transactivation activity of Ets-1. TGF-beta augmented ets-1 mRNA expression and Ets-1 protein synthesis in ECV304 cells to the level equivalent to bFGF. When the DNA binding activity of Ets-1 protein was examined, bFGF was found to enhance DNA-Ets complex formation, whereas TGF-beta attenuated basal as well as bFGF-enhanced DNA-Ets complex formation. As a result, TGF-beta attenuated the promoter activity driven by Ets-1. The DNA binding of Ets-1 protein was enhanced by the initial 4-hour bFGF treatment and the subsequent 8-hour cycloheximide treatment. When TGF-beta replaced cycloheximide in the subsequent 8-hour treatment, TGF-beta inhibited this bFGF-enhanced DNA-Ets complex formation. When TGF-beta and cycloheximide were simultaneously added in the subsequent 8-hour treatment, the inhibitory effect of TGF-beta on bFGF-enhanced DNA-Ets complex formation was completely abolished. These results suggest the possibility that TGF-beta attenuates the transactivation activity of Ets-1 by inducing a protein that interferes with the binding of Ets-1 to the DNA binding site.

Cell Line, Transformed↗
PubMed2001

Retinoic acids repress the expression of ETS-1 in endothelial cells.

The transcription factor ETS-1 expressed in endothelial cells (ECs) regulates angiogenesis by inducing MMP-1, MMP-3, MMP-9, u-PA and integrin beta3 in endothelial cells (ECs). Here, we examined whether antiangiogenic retinoic acids affect the expression of ETS-1 in ECs. The expression of ets-1 mRNA was up-regulated in sparse to subconfluent ECs and down-regulated in confluent ECs. When confluent ECs were stimulated with basic fibroblast growth factor (bFGF), ets-1 mRNA was induced. All-trans retinoic acid (ATRA) as well as 9-cis retinoic acid reduced the augmented expression of ets-1 mRNA in both subconfluent ECs and bFGF-treated confluent ECs. This inhibitory effect of ATRA was dose dependent and was evident at a concentration as low as 10(-7) M. ATRA did not alter the stability of ets-1 mRNA. Moreover, promoter analysis indicated that ATRA repressed the expression of ets-1 mRNA at transcriptional level. As a result, ATRA reduced the binding of ETS-1 protein to the ETS binding motif. These results indicate that the anti-angiogenic effect of retinoic acids is mediated at least in part by the transcriptional repression of ets-1 mRNA in ECs.

Alitretinoin↗
PubMed2001

The dorsiflexion-eversion test for diagnosis of tarsal tunnel syndrome.

BACKGROUND: The clinical diagnosis of tarsal tunnel syndrome lacks objectivity and consistency. We have devised a new diagnostic physical examination test in which the tibial nerve is compressed as it runs beneath the flexor retinaculum behind the medial malleolus. In this test, the ankle is passively maximally everted and dorsiflexed while all of the metatarsophalangeal joints are maximally dorsiflexed and held in this position for five to ten seconds. METHODS: We performed this test on fifty normal volunteers (100 feet) and on thirty-seven patients (forty-four feet) treated operatively for tarsal tunnel syndrome between 1987 and 1997. We performed the maneuver both preoperatively and postoperatively and recorded any consequent changes in the signs and symptoms; during the operation we observed the altered anatomical relationships in the tarsal tunnel that were produced by the maneuver. The average duration of follow-up was three years and eleven months. RESULTS: Before the operation, the signs and symptoms of tarsal tunnel syndrome were intensified or induced by the maneuver in fifteen of the twenty feet of the patients who reported numbness, in fifteen of the seventeen feet of those who reported pain alone, and in six of the seven feet of those who had combined numbness and pain. Local tenderness was intensified in forty-two of forty-three feet, and it was induced in one foot in which it had been previously absent. A Tinel sign became more pronounced in forty-one feet, and the sign was induced in three feet in which it had been absent previously. During the operation, the tibial nerve was stretched and compressed beneath the laciniate ligament when the ankle was dorsiflexed, the heel was everted, and the toes were dorsiflexed. Preoperative signs and symptoms disappeared on an average of 2.9 months after the operation, and they could not be induced by repeating the test except in three patients, all of whom had tarsal tunnel syndrome subsequent to a fracture of the calcaneus. In the normal volunteers, no symptoms or signs could be induced by the test. CONCLUSION: This new physical examination test is effective in facilitating the diagnosis of tarsal tunnel syndrome.

Adolescent↗
PubMed2001

Late occurrence of diffuse cerebral swelling after intracerebral hemorrhage in a patient with the HELLP syndrome--Case report.

Hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome can occur at any time in the course of pregnancy and is associated with many complications including fatal stroke. A 37-year-old female presented with HELLP syndrome causing an intracerebral hematoma, which was treated by evacuation and mild hypothermia. Unexpected diffuse cerebral swelling occurred on the 15th day of the initially favorable postoperative course. Considerable impairment of consciousness persisted despite conservative therapy. Serial computed tomographic findings indicated delayed cerebral vasospasm as the cause of the swelling. Particularly careful management is required even beyond the first 2 weeks for patients with stroke as a complication of HELLP syndrome.

Adult↗
PubMed2001

[Ventilatory failure due to the limitation of chest movement in a case of FPS].

A 72-year-old woman presented with cervicothoracal skin lesions mimicked to scleroderma and muscular atrophy in 1996. Because of the elevation of serum creatinine kinase (CK), muscular biopsy was performed at another institution. Under the diagnosis of polymyositis, she was treated with corticosteroid. Despite of the decrease in serum CK levels by corticosteroid therapy, skin lesions and mascular dystrophy gradually worsened to extend to the regions of major pectoral, paravertebral, and femoral muscles. In 1997, she was admitted to our hospital because of dyspnea. On admission, the limitation of the chest movement was obvious and she developed respiratory arrest due to CO2 narcosis. The femoral magnetic resonance image (MRI) showed increased signal intensity of subcutaneous tissues and fascia on T2-weighted image. The block biopsy specimens obtained from the cervical lesion revealed fibrotic thickness and chronic inflammation of subcutaneous septa, fascia, and perimysium. She was treated by mechanical ventilation and cimetidine and weekly methotrexate were added to the corticosteroid therapy because of the diagnosis of FPS. Thereafter, the skin and muscular lesions as well as the MRI findings were improved. The concept of FPS was proposed by Naschitz et al. This condition is pathologically characterized by cicatrizing fascitis, septal and lobular panniculitis, and perimysial fibrosis and peripheral blood and tissue eosinophilia is not important for diagnosis. FPS includes classical eosinophilic fascitis but is also associated with several disorders such as malignancy. This case is suggestive of the therapeutic consideration of FPS in terms of the response to cimetidine and MTX.

Aged↗
PubMed2001

Decay in prepulse facilitation of calcium channel currents by Gi/o-protein attenuation in hamster submandibular ganglion neurons, but not Gq/11.

The calcium ion influx through voltage-dependent calcium channels (VDCCs) has a vital role in the control of neurotransmitter release and membrane excitability. Prepulse facilitation is a phenomenon in which a strong depolarizing pulse induces a form of the VDCCs that exhibits an increased opening probability in response to a given test potential; this persists for several seconds after repolarization. It has been reported that prepulse facilitation occurs via dissociation of the guanosine triphosphate (GTP)-binding proteins (G-proteins) from the VDCCs and that recovery from facilitation involves rebinding of the G-proteins. The heterotrimeric G-proteins act as switches that regulate information processing circuits connecting cell surface G-protein-coupled-receptors to a variety of effectors. In this study, we have studied the characterization of G-protein subtypes in prepulse facilitation of VDCCs currents (Ica) in hamster submandibular ganglion (SMG) neurons, using whole-cell patch clamp recordings. Under control conditions, with GTP (0.1 mM) in the recording pipette, the rate of prepulse facilitation was 19.0 +/- 1.9% (n = 13). Intracellular dialysis with GDP-beta-S (0.1 mM), G-protein blocker, and pretreatment of neurons with N-ethylmaleimide (NEM) (100 microM for 2 min), Gi/o blocker, attenuated the rate of prepulse facilitation. Intracellular dialysis of anti-Gq/11-antibody did not alter it. These results suggest that prepulse facilitation of VDCCs is due to Gi/o-types of G-protein, but not to the Gq/11-type, in SMG neurons.

Animals↗
PubMed2001

Adverse effects of excess lysine in calves.

Two main trials and three preliminary experiments were conducted in order to examine adverse effects of excess lysine in 140- to 150-kg Holstein bull calves. The animals had been trained to maintain reflex closure of the reticular groove after weaning and were fed a corn and soybean meal diet. In Trial 1 (n = 30), administration via the reticular groove of 0 to 64 g/d of lysine as L-lysine monohydrochloride resulted in a linear decrease in DMI and N utilization efficiency, with notably lower values at 64 g/d, although ADG and gain/feed ratio were not affected. Plasma arginine and ornithine did not decrease but rather increased over that range. Free lysine but not free arginine was detected in urine. In addition, free ornithine was excreted into urine only when 64 g/d was administered. Unexpectedly, severe but transient diarrhea occurred when 64 g/d of lysine were administered. Preliminary experiments revealed that a single administration of more than 32 g of lysine as L-lysine monohydrochloride could result in diarrhea, and the diarrhea was proven to be due to the lysine itself and not to the HCl portion. In Trial 2 (n = 15), a single administration of 40 or 60 g of lysine as L-lysine monohydrochloride resulted in increased fecal excretion of free lysine and ornithine, especially the latter, although free arginine was not detected in feces. These results suggested that diarrhea could occur almost concurrently with an imbalance in calves when 64 g/d of lysine was administered. However, lysine did not antagonize arginine at that level or at lower levels. The remarkable increase in fecal ornithine may be somehow related to the development of diarrhea from excess lysine.

Animals↗
PubMed2001

Quantitative evaluation of selenium contained in tea by high performance liquid chromatography.

For determination of selenium (Se) in biological materials, an improved method based on high performance liquid chromatographic determination of the fluorophore formed by reaction of selenite with 2,3-diaminonapththalene was developed. The concentration detection limits were 0.5 ng/g in dried materials and 0.03 ng/mL in fluid materials. In quadruplicate assays of 11 biological reference materials using the proposed method, measured Se concentrations were not significantly different from their certified values. Thus, the proposed method is reliable and suitable for the determination of trace levels of Se in foods. Using the proposed method, Se concentrations in various kinds of tea were determined to assess the contribution of tea to daily Se intake in the Japanese population. Se concentration in the leaves of general black, green and oolong tea obtained in local retail stores was 33 +/- 19 ng/g (n=440). The leaves of a particular Chinese green tea sold under the name "high Se tea" were found to contain 455 +/- 184 ng/g (n= 14) of Se. While the percentage of Se extractable by infusion was less than 5% for the general teas, that in the high Se tea was more than 20%. These results indicated that intake of tea does not contribute to daily Se intake in the Japanese population. However, since infusions from high Se tea contained over 5 ng/mL of Se, consumption of over 1 L/d of tea derived from such high Se teas may increase the daily Se intake by close to 10%.

2-Naphthylamine↗
PubMed2001

[Transsphenoidal surgery assisted by navigation system].

Microneurosurgical technique combined with precise localization of lesions, can minimize the invasiveness of neurosurgical procedures. This report describes the usefulness of the neuronavigation system in transsphenoidal surgery. Nineteen transsphenoidal operations for sellar lesions including pituitary adenoma, clival chordoma, Rathke's cleft cyst and suprasellar germinoma were assisted by the optical tracking system (OTS). Operations were performed either through the sublabial or the endonasal approach using an operative microscope and, to a certain extent, the endoscope. All five microadenomas were totally removed. The tumors could be precisely localized by the navigation system. Four out of seven macroadenomas were totally removed. The operations were assisted effectively by the excellent guidance to the lateral margin of the tumors and the internal carotid arteries provided by the navigation system. The endonasal approach, in which the surgeon looks through a nostril at the sellar floor obliquely, was especially facilitated by the three-dimensional view provided by the system. The navigation system, however, was not useful in estimating the amount of the suprasellar residual tumor because of the dislocation that occurred during the tumor removal.

Adenoma↗
PubMed2001

[Pathology and significance of leptin resistance in obesity].

Leptin, the protein product of the ob gene, is predominantly secreted from white adipose tissue, and acts on the brain to regulate food intake, energy expenditure, and neuroendocrine function. Obese rodent and humans are mostly associated with high circulating leptin levels. These findings have led to the conclusion that obese individuals are relatively insensitive to endogenous leptin termed 'leptin resistance'. The potential sites for leptin resistance include the blood-brain-barrier transport system and the leptin signaling mechanism in leptin-responsive neurons in the hypothalamus. In this review, we describe leptin, leptin receptor, and potential hypothesis of leptin resistance.

Animals↗
PubMed2001

Stimulatory effect of pseudomonal elastase on collagen degradation by cultured keratocytes.

PURPOSE: The pathobiology of corneal ulceration induced by Pseudomonas aeruginosa was investigated by characterization of the pseudomonal pathogenic factors responsible for degradation of the collagen matrix. METHODS: Three-dimensional gels of type I collagen containing (or not) rabbit keratocytes were incubated in the presence of either culture supernatant of P. aeruginosa strain PAO1 or pseudomonal pathogenic factors (elastase, lipopolysaccharide, or exotoxin A), and the extent of collagen degradation was assessed after 24 hours by measurement of released hydroxyproline. Activation of matrix metalloproteinases (MMPs) produced by keratocytes was also examined by gelatin zymography and immunoblot analysis. RESULTS: In the absence of keratocytes, the PAO1-conditioned medium increased the extent of collagen degradation. The conditioned medium also promoted keratocyte-mediated collagen degradation. Of the pseudomonal pathogenic factors examined, only elastase degraded collagen directly as well as stimulated keratocyte-mediated collagen degradation. Culture supernatant of elastase-deficient P. aeruginosa (lasR or lasB) mutants had no effect on collagen degradation in the absence or presence of keratocytes. Elastase also induced the conversion of the inactive precursors of MMP-1, -2, -3, and -9 produced by keratocytes to the active forms of the enzymes. CONCLUSIONS: These results suggest that pseudomonal elastase both degrades type I collagen directly and promotes collagen degradation mediated by keratocytes, the latter effect being likely attributable, at least in part, to the activation of proMMPS:

ADP Ribose Transferases↗
PubMed2001

[Brown-Séquard syndrome and cervical CSF leakage due to a knife injury: a case report].

We report a case of Brown-Séquard syndrome and cervical CSF leakage caused by a knife injury. A 34-year-old man was involved in a fight and was stabbed on his occiput and back with a knife. Neurological examination on admission showed right hemiparesis, right hemihypesthesia and left hemihypalgesia, indicating Brown-Séquard syndrome. Furthermore, cerebrospinal fluid was leaking from the occipital stab wound. Head CT scan showed massive accumulation air in the subarachnoid space. Cervical MRI showed that the injury tract reached to the space between the occipital bone and the atlas. One week after admission, suboccipital craniectomy and duraplasty were performed because of continuous CSF leakage. Although, the CSF leakage recurred due to the wound infection, it disappeared naturally as the patient's general condition improved. Follow-up MRI studies demonstrated the cervical spinal lesion as hyperintensity on T2WI, which localized at the right side of the spinal cord. The patient's hemiparesis gradually improved and he underwent rehabilitation. Spinal cord injury due to a stab wound by a knife is rare in Japan. In this case, we suppose that the mechanism of spinal cord injury was due to direct injury by a knife avoiding the lateral corticospinal tract because his right hemiparesis obviously improved.

Adult↗
PubMed2001

[Cellular origin of human B-cell neoplasms and Hodgkin's disease based on analysis of somatic hypermutations in the immunoglobulin variable region genes].

In response to antigen stimulation, B cells undergo a germinal center(GC) reaction such as somatic hypermutations of the immunoglobulin variable region genes, which results in the production and selection of antigen-specific antibodies with increased affinity. Therefore, somatic hypermutations are considered to be a hallmark of GC B cells and their descendants. Pre-GC B cells(precursor B cells, immature B cells, naive B cells and CD5+ B cells) carry no somatic hypermutations, whereas GC B cells and post-GC B cells(memory B cells and plasma cells) express somatic hypermutations. This phenomenon is useful in identifying the cellular origin of various B-cell neoplasms. Precursor B-lymphoblastic leukemia/lymphoma, mantle cell lymphoma, and most B-CLL originate from pre-GC B cells, and follicular lymphoma, Burkitt's lymphoma, marginal zone B-cell lymphoma, diffuse large B-cell lymphoma and myeloma from GC B cells or post-GC B cells. Nodular lymphocyte-predominant Hodgkin's disease and most classical types of Hodgkin's disease are derived from GC B cells. Most human-B cell neoplasms including Hodgkin's disease are derived from GC B cells or their descendants. Molecular processes that modify the DNA of GC B cells, such as somatic hypermutation, class switching and receptor editing occur in the environment of the GCs, and increase the risk of malignant transformation.

Hodgkin Disease↗
PubMed2001

Immunoglobulin heavy chain gene analysis of ocular adnexal extranodal marginal zone B-cell lymphoma.

PURPOSE: To clarify the cellular origin of extranodal marginal-zone B-cell lymphoma (EZML) of the mucosa-associated lymphoid tissue (MALT) type in ocular adnexa, the somatic mutation was analyzed in the immunoglobulin heavy-chain variable region (VH) gene. METHODS: Eight cases of EZML in the orbit and four in the conjunctiva were studied. The VH genes were amplified by a seminested PCR and sequenced directly. These were compared with the closest published VH germline segments to determine the somatic mutation frequency. Intraclonal microheterogeneity, which was termed the ongoing mutation frequency in the current study, was estimated by counting the number of single nucleotide substitutions in individual clones and dividing by the total number of nucleotides analyzed. Nine cases of gastrointestinal EMZL were also examined for comparison. RESULTS: The somatic mutation frequency varied between 2.0% and 12.7%, with a mean value of 7.9%. Ten cases with intraclonal microheterogeneity showed between one and six further substitutions. The average of ongoing mutation frequency was 0.11%, with a range of 0% to 0.25%. In the gastrointestinal EMZLs, the average of somatic mutation frequency was 8.5% (1.5%-14.2%) and of ongoing mutation frequency was 0.51% (0.25%-0.75%). CONCLUSIONS: The average of ongoing mutation frequency in ocular adnexal EMZL was lower than that in gastrointestinal EMZL. Both ocular adnexal and gastrointestinal EMZLs are derived from postgerminal center memory B cells, but the low ongoing mutation frequencies of ocular adnexal EMZL may result from less antigen stimulation and follicular colonization in the orbit relative to gastrointestinal EMZL.

Adult↗
PubMed2001

[Surgical management of non-tuberculous mycobacteriosis and tuberculosis of the lung].

From 1990 to 1999, three patients with non-tuberculous mycobacteriosis and 14 patients of tuberculosis underwent pulmonary resection in the National Sanatorium Ehime Hospital. Of the patients with tuberculosis, two were multiple drug-resistant cases and twelve cases were suspected of lung cancer before diagnostic resection. All three patients with non-tuberculous mycobacteriosis were symptomatic, had chest cavities in the lung, and were sputum-culture positive. There were no operative death in all patients, and one case of post-operative complication. Two patients, one with non-tuberculous mycobacteriosis and another with tuberculosis, failed in sputum negative conversion. The former had been treated for a long time preoperatively. Early resection in patients of pulmonary non-tuberculous mycobacteriosis and of pulmonary multiple drug-resistant tuberculosis is recommended to prevent further progression of pulmonary lesions.

Adult↗
PubMed2001

Case report. Lymphatic vessel-type sporotrichosis: immunohistochemical evaluation and cytokine expression pattern.

A 57-year-old male carpenter living in Sagamihara, Kanagawa Prefecture, visited the Department of Dermatology of Kitasato University Hospital because an ulcer which appeared in his left forearm around May 1992 had spread gradually. An oval, shallow ulcer measuring 39 mm x 18 mm was found on the flexor aspect of the left forearm. Histopathological examination showed partial ulceration on the epidermis and marked cell infiltration throughout the entire dermal layer with an abscess in the centre and granulomatous reactions around it. PAS-positive spores were present between infiltrating cells and in giant cells in abscess and in granulomatous reactions. The skin lesion rapidly disappeared after beginning treatment with 125 mg day(-1) terbinafine and only a slight redness remained 14 weeks after starting the treatment. At this time the culture was negative. We conducted immunohistochemical examinations of the affected skin before, during and after starting treatment with terbinafine and studied local expression of cytokines at the affected lesion.

Arm↗
PubMed2001

Role of transcription factors in angiogenesis: Ets-1 promotes angiogenesis as well as endothelial apoptosis.

Angiogenesis is a complex phenomenon that requires at least migration, proliferation, and tubular morphogenesis of endothelial cells (ECs). Some genes are expressed in ECs during these processes, and therefore the regulation of gene expression in ECs is critical. Increasing evidence suggests that the Ets family of transcription factors plays an important role in angiogenesis. We observed that Ets-1, a prototype of the Ets family of transcription factors, promoted angiogenesis by inducing the expression of matrix metalloproteinases and integrin beta3 in ECs, and the elimination of the transactivation activity of Ets-1 by a dominant negative molecule inhibited angiogenesis. Apoptosis, a term used to describe the terminal morphological and biochemical events seen in programmed cell death, is critical for the development or reconstitution of multicellular organs. Apoptosis of ECs is observed at the initiation of angiogenesis, at the branching or communication with newly formed vessels, and at the regression of neo-vessels. The Ets family of transcription factors is generally thought to be anti-apoptotic. However, there are conflicting reports on the role of Ets-1 in apoptosis. We examined the role of Ets-1 in apoptosis of ECs and found that Ets-1 was pro-apoptotic to ECs by modulating the expression of several apoptosis-related genes.

Animals↗