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Biomedical subjects

Y Kojima

Publications and source records attributed to Y Kojima.

At least 289 records · Page 16Linked to original sources
PubMed1993

Nucleotide sequence of the Clostridium stercorarium xylA gene encoding a bifunctional protein with beta-D-xylosidase and alpha-L-arabinofuranosidase activities, and properties of the translated product.

The nucleotides of the beta-xylosidase (xylA) gene from Clostridium stercorarium were sequenced. A single open reading frame of 473 codons specifying the subunit (MW 53,340) of xylosidase was identified. The N-terminal amino acid sequence and molecular weight estimated by SDS-polyacrylamide gel electrophoresis of the purified enzyme were quite in agreement with those deduced from the nucleotide sequence. Analysis of the enzyme by gel filtration on an HPLC column gave a molecular weight of 220,000, suggesting that the native enzyme is a tetramer composed of 4 identical subunits. The pH optimum was 7.0 and quite stable over the pH range of 5 to 10 at 4 degrees C. The optimum temperature was 65 degrees C. Vm was estimated to be 5.9 nmol/min/micrograms for p-nitrophenyl-beta-D-xylopyranoside and 16.7 nmol/min/micrograms for p-nitrophenyl-alpha-L-arabinofuranoside, while Km was estimated to be 2.5 mM for p-nitrophenyl-beta-D-xylopyranoside and 17.6 mM for p-nitrophenyl-alpha-L-arabinofuranoside.

Amino Acid Sequence↗
PubMed1993

Prolongation of rat cardiac allograft survival by a monoclonal antibody: anti-rat intercellular adhesion molecule-1.

A mouse monoclonal antibody 1A29, which binds to the rat intercellular adhesion molecule-1 (ICAM-1), was studied for its effect on cardiac allograft survival. Expression of ICAM-1 was detectable only on vascular endothelium in normal heart, but was induced on myocardium associated with interstitial mononuclear cell infiltration during acute rejection. Treatment with monoclonal antibody 1A29 for 10 days after transplantation in 15 rats significantly prolonged allograft survival (mean(s.d.) 18(2) days; P < 0.001), as compared with 15 isotype-matched control monoclonal antibody (mean(s.d.) 10(1) days) recipients. Five-day treatment with monoclonal antibody 1A29, when started at 5 days after transplantation (the time for which acute rejection is ongoing), also significantly extended the survival (mean(s.d.) 12(1) days; P < 0.01) in seven rats. On histological examination, treatment with monoclonal antibody 1A29 reduced the degree of T-cell infiltration of both CD4+ and CD8+ subsets, and greatly reduced myocardial necrosis, vascular injury and intravenous thrombi. These results indicate that an anti-ICAM-1 monoclonal antibody can be used to prevent or treat acute rejection in the rat cardiac allograft model and suggest that human ICAM-1 is an important target for immunosuppression in clinical organ transplantation.

Animals↗
PubMed1993

[A new approach to intra-arterial infusion chemotherapy for breast cancer].

To perform intra-arterial infusion chemotherapy for breast cancer, we cannulated the internal thoracic and lateral thoracic arteries, respectively. In the past, we could catheterize the former vessel only 43% of the time using gross observation, but now we can do so 100% of the time with an operating microscope apparatus. It was selectively done in the latter vessel through the brachial artery after the Seldinger method. An 82-day-long intra-arterial chemotherapy could be continued without any restriction in the patient's daily life, and the tumor decreased in size considerably. Nevertheless, intra-arterial preservation of the catheter and administration of anticancer drugs decrease local blood flow and produce thromboangitis, resulting in an extremely hypovascular state of tumor lesion. These changes, observed both angiographically and fluorographically, pose problems which must be resolved for long-term intra-arterial infusion chemotherapy.

Adult↗
PubMed1993

Sex-related differences of acetohexamide reductase activities in the liver and kidney of various mammalian species.

Sex-related differences of acetohexamide reductase activities in cytosol and microsomes from the liver and kidney of the rat, mouse, guinea pig, hamster and rabbit were examined. Among animal species tested, the rat, guinea pig and rabbit exhibited sex-related differences in the activities. The activities in liver cytosol of the rat and rabbit were higher in the females than in the males, whereas the activity in kidney cytosol of the rabbit was higher in the male than in the female. Furthermore, the activities in liver and kidney microsomes of the rat and that in kidney microsomes of the guinea pig were much higher in the males than in the females. It is interesting to note that significant sex-related differences of acetohexamide reductase activities are found in some animal species other than the rat.

Alcohol Oxidoreductases↗
PubMed1993

[The effect of organophosphorus pesticide (fenthion) on GABA-cells in the central nuclei].

Organophosphorus pesticide (OP) produces abnormal eye movements. This is possibly due to an inhibition of central cholinergic neurons as well as GABAnergic neurons. Using anti-GABA-antibody, the authors studied the effect of OP on GABA-positive cells in the central nervous system. Fenthion (dimethyl 4-methylthion-m-tolyl-phosphorothionate, 20 mg/kg body weight), was given subcutaneously to the dorsal portion of Wistar rats for 30 days. After staining, the number of GABA-positive cells were counted at the superior colliculus (SC), the cerebellum, and the substantia nigra reticularis (SNR) on day 6, 10, 14, 18, 22, 26 and 30 respectively. The number of GABA-positive cells reduced in the cerebellum, SNR and SC decreasing remarkably after the initiation of fenthion administration. The number of GABA-positive cells also decreased in lateral geniculate nucleus and pretectal nuclei. Those results suggest that the reduction of GABA-positive cells produces abnormal eye movements in human OP intoxication.

Animals↗
PubMed1993

[Effects of Perilla frutescens extract on anti-DNP IgE antibody production in mice].

Perilla frutescens is a Chinese herbal medicine. In this study, we prepared an extract of Perilla frutescens (PFE) and examined its effects on anti-DNP antibody responses in mice. The mice were immunized with DNP-ovalbumin in Alum adjuvant. To examine the effects of PFE on primary antibody responses, PFE was intraperitoneally injected the day before primary immunization. Anti-DNP IgE antibody production was found to be markedly suppressed by PFE injection. Then, we examined the effects on secondary antibody responses. PFE was injected only the day before secondary immunization. Anti-DNP IgE production was markedly suppressed, but IgG response was not so affected. These results suggest that the immunosuppressive effects of PFE are preferentially on IgE production and that PFE may be useful for the suppression of IgE antibody in certain allergic disorders.

Animals↗
PubMed1993

[Argyrosis of the urinary tract after silver nitrate instillation: report of a case].

A 69-year-old woman was referred to our hospital for evaluation of pyuria and renal dysfunction. Twenty days earlier, the patient had undergone silver nitrate retrograde instillations for essential renal bleeding. Routine laboratory findings showed renal dysfunction with a serum creatinine concentration of 7.2 mg/dl and blood urea nitrogen concentration of 68 mg/dl. The urine contained numerous red cells and white cells. The plain X-ray film of the abdomen revealed right renal calcification. Computed tomographic scan confirmed the calcifications in the right renal collecting systems and parenchyma. The most likely diagnosis was argyrosis of the upper urinary tract. The patient underwent a right nephrectomy. Histopathological examination of the specimen showed that the renal pelvis was filled with blood clots. Laboratory evaluation including serum creatinine concentration and urinalysis revealed normal parameters postoperatively. We conclude that this patient developed argyrosis of the urinary tract, and review previously published papers concerning complications of silver nitrate instillation.

Administration, Intravesical↗
PubMed1993

[Treatment results of intra-arterial ACNU infusion chemotherapy for primary cerebral malignant lymphoma].

From May, 1987 to January, 1991, eight patients harboring primary cerebral malignant lymphoma (primary, six cases; recurrent, two cases) were treated by intra-arterial ACNU infusion chemotherapy. All but two cases also had hyperosmotic blood brain barrier (BBB) modification. Six primary cases had conventional teletherapy of 46-58.7 Gy (average 54.1 Gy) and one recurrent case had been irradiated again by 18 Gy. The follow-up period was 3 to 67.5 months (average 21.4 months). In six cases demonstrating measurable tumors on diagnostic images, all showed a complete response. The 1- and 2-year survival time was 50.0% and 37.5%, respectively, with a median survival time of 13.0 months. These were somewhat better than our previous results, but not better than those in the literature. Although intra-arterial ACNU infusion chemotherapy with BBB modification was not considered superior to other chemotherapy regimens, it yielded some long-surviving cases. Hence this chemotherapy is still worth using for treatment of primary cerebral malignant lymphoma.

Adult↗
PubMed1993

[A case of eosinophilic granuloma associated with a brain lesion].

A 32-year-old man was hospitalized due to right pneumothorax. Chest X-ray showed interstitial shadows predominantly in the upper and middle lung fields. Eosinophilic granuloma was diagnosed by transbronchial lung biopsy. He had a history of paraesthesia in the right arm for 6 months prior to the pneumothorax. Initially, head CT showed an iso-dense area enhanced with contrast medium in the left temporal lobe. Two weeks after the onset of paraesthesia, head CT showed an iso-dense lesion surrounded by low density area. Subjective symptoms disappeared in a month, and no abnormalities on head CT were seen at 2 months. It is highly suspected; therefore, that the present case of eosinophilic granuloma was associated with a brain lesion.

Adult↗
PubMed1992

Bilateral innervation of the musculus levator palpebrae superioris by single motoneurons in the monkey.

The location of motoneurons innervating the musculus levator palpebrae superioris (LPS) was studied in the monkey (Macaca irus) by using Fast blue (FB) and propidium iodide (PI) as retrograde neuronal tracers. In each monkey, FB was injected into the LPS of one eye and PI into the LPS of the other eye. Neuronal cell bodies labeled with FB and/or PI were seen intermixed bilaterally through the entire rostrocaudal extent of the central caudal nucleus. While single-labeled (70%) cell bodies predominated, many double-labeled (30%) cell bodies were also encountered. Each of the double-labeled neurons was concluded to supply the LPS on both sides by way of axon collaterals.

Animals↗
PubMed1992

Inhibition of tumor invasion and extracellular matrix degradation by ubenimex (bestatin).

We have investigated the effect of the immunomodulator ubenimex (hereafter referred to as bestatin) on the enzymatic degradation of the extracellular matrix by human renal cell carcinoma SN12M cells during the invasive process. The invasion of SN12M cells into reconstituted basement membrane (Matrigel) was inhibited by the presence of bestatin in a concentration-dependent manner. However, bestatin did not have any effect on tumor cell adhesion and migration to the extracellular matrices which may be involved in tumor cell invasion. Bestatin inhibited the degradation of type IV collagen by tumor cells, but not by tumor-conditioned medium (TCM), in a concentration-dependent manner. We also found that bestatin inhibited hydrolysing activities towards substrates of aminopeptidases in SN12M cells. Since bestatin was found to inhibit aminopeptidase activity, the inhibition of tumor invasion by bestatin is likely to be associated with its action as an enzyme inhibitor. Bestatin only slightly inhibited tumor cell plasmin activity, which can lead to the conversion of the latent collagenase to the active form, but this slight effect was not significant. The zymography of TCM from SN12M cells showed that the treatment of tumor cells with bestatin resulted in the disappearance of the 68 kDa type IV collagenase-enzyme level (active form) and slight reduction of the 72 kDa type IV collagenase-enzyme level (latent form). These results indicated that bestatin may inhibit tumor cell invasion through a mechanism involving its inhibitory action on aminopeptidases in tumor cells, suggesting that the aminopeptidase may partly be associated with the conversion of a latent form of type IV procollagenase to an active form or the secretion of the collagenases from tumor cells.

Adult↗
PubMed1992

A case of duodenal carcinoma presenting as a submucosal tumor.

This paper describes a patient with duodenal carcinoma showing the features of a submucosal tumor, leading to difficulty in making an accurate preoperative diagnosis. A 63-year-old woman was admitted for investigation of a duodenal mass. An examination of the upper gastrointestinal tract revealed a semicircular compression of the stomach and the duodenum. Endoscopy of the stomach and duodenum disclosed a hemispherical tumor with a deep ulcer in the apex. Computer tomography revealed a tumor of about 5 cm in diameter at the same site. Laparotomy was performed under the tentative diagnosis of a submucosal tumor. A tumor was found occupying the duodenum, which compressed the gastric antrum exteriorly, and was also adherent to the head of the pancreas by direct invasion. A curative resection was performed by combining a pancreatoduodenectomy with a transverse colectomy along with regional lymph node clearance. A microscopic examination showed that the tumor contained neoplastic cells growing in a tubular pattern, particularly in its peripheral regions. Thus, this lesion was finally diagnosed as primary adenocarcinoma of the duodenum.

Adenocarcinoma↗
PubMed1992

Postoperative complications and survival after pancreatoduodenectomy in patients aged over 70 years.

An analysis of postoperative complications and survival was conducted in 31 patients undergoing pancreatoduodenectomy (PD) for carcinoma of the pancreas or periampullary carcinoma. Of them, 11 were over 70 years of age and 20 were under 70. Anastomotic leakage was the most common complication after PD. Definite pancreatic leakage was found in one patient in the over 70 group, and one case each of pancreatic, biliary, and gastric leakage were found in the under 70 group. All complications were treated conservatively without any further operative intervention. The overall morbidity rate was 41.9% (13/31), being 45.5% (5/11) in the over 70 group and 40.0% (8/20) in the under 70 group, and no operative deaths occurred within 30 days after surgery. The cumulative survival rate of the patients aged over 70 years with carcinoma of the pancreas or periampullary carcinoma did not differ significantly from the rate of those under 70. It was thus concluded that PD achieves an adequate prognosis and survival in patients over 70 years of age.

Adult↗
PubMed1992

Verbal versus non-verbal visual evoked potentials: Kanji versus line drawings.

Cortical areas related to perception of verbal and non-verbal stimuli were studied using VEPs. Kanji characters, line drawings (LD), or a blank were displayed. Verbal VEPs were obtained by subtracting the blank-VEPs from the Kanji-VEPs, and non-verbal VEPs by subtracting the blank-VEPs from the LD-VEPs. Both the verbal and non-verbal VEPs showed a negative peak (100-300 msec) focally over bilateral occipital, posterior temporal and parietal areas, and a positive peak diffusely over frontal halves. Differences between the non-verbal from the verbal VEPs showed an initial peak (100-200 msec) focally over bilateral occipital and posterior temporal areas, followed by a peak (200-300 msec) focally over bilateral posterior temporal areas. The frontal areas diffusely showed peaks at 100-200, 200-300 and 300-400 msec. Left-right asymmetries of both the verbal and non-verbal VEPs showed peaks between 100 and 300 msec over posterior temporal, parietal, and occipital areas. Left-right asymmetries of the subtraction to the non-verbal from the verbal VEPs showed a peak (100 msec) over occipital and parietal areas, and a broader peak over posterior temporal area (100-200 msec). Bilateral occipital, posterior temporal, and parietal areas are focally activated by the two perceptions (100-300 msec), while frontal areas are activated diffusely. Further, different processes may be focally involved between the hemispheres over occipital (100-200 msec) and posterior temporal (100-200 and 200-300 msec) regions. Initial left-right asymmetries of the subtracted VEP between the two perception would occur over occipital and parietal areas (100 msec) and last for 200 msec over posterior temporal area.

Acoustic Stimulation↗