Search PubMed⌕ Search

Biomedical subjects

A Kobayashi

Publications and source records attributed to A Kobayashi.

At least 181 records · Page 10Linked to original sources
PubMed1999

Inhibitory effect of sulfur-containing compounds in Scorodocarpus borneensis Becc. on the aggregation of rabbit platelets.

The inhibitory effects of three pure compounds isolated from wood garlic, 2,4,5-trithiahexane (I), 2,4,5,7-tetrathiaoctane (II), and 2,4,5,7-tetrathiaoctane 2,2-dioxide (III), on rabbit platelet aggregation induced by collagen, arachidonic acid, U46619, ADP (adenosine 5'-diphosphate), PAF (platelet aggregating factor), and thrombin were studied in vitro. The anti-aggregating activity of 2,4,5,7-tetrathiaoctane 4,4-dioxide (IV) was also measured with collagen and arachidonic acid. I, II, III, and IV inhibited the platelet aggregation induced by all tested agonists. I, II, and III exhibited a stronger inhibitory effect against the thrombin-induced aggregation of GFP (gel-filtered platelets) than against the aggregation induced by the other agonists. Notably, the IC50 value for III was 4 microM, which is approximately 2.5 times stronger than MATS (methyl allyl trisulfide), a major anti-platelet compound isolated from garlic. In inhibiting collagen-induced aggregation, II was as potent as MATS and aspirin, with a marked disaggregation effect on the secondary aggregation by arachidonic acid, at the rate of 47.05%/min at a concentration of 10(-4) M. I, II, and III also suppressed U46619-induced aggregation. These results suggest that sulfur-containing compounds in wood garlic not only inhibit arachidonic acid metabolism but also suppress aggregation in association with the function of the platelet plasma membrane.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1999

An investigation of the relationship between duct system and A cell-rich and PP cell-rich pancreatic islets in the canine pancreas.

The pancreata of four six-month-old dogs of the same mother, two with both the pancreatic and accessory pancreatic ducts (X-type) and two with only the accessory pancreatic duct (Y-type), were examined in this study. To clarify the relationships between the type of pancreatic duct system and the composition of pancreatic endocrine cells, the pancreata were examined immunohistochemically using antiserum against four types of pancreatic hormones (glucagon, insulin, somatostatin and pancreatic polypeptide). In all areas of the X- and Y-type duct system pancreata, B cells accounted for 52-82% of the total number of islet cells, and D cells accounted for 4-15%. In the X-type ducts system, the percentages of A and PP cells in the right and left lobes of the pancreas differed greatly. It was found that A and PP cells appear in inverse proportion to each other and that there exist A cell-rich and PP cell-rich pancreatic islets. The A cell-rich pancreatic islets appeared in the left lobes along the accessory pancreatic duct, while the PP cell-rich pancreatic islets were observed in the right lobes along the pancreatic duct. The body of the pancreas contained both A cell-rich and PP cell-rich pancreatic islets. In the Y-type duct systems, A cell-rich pancreatic islets appeared in the right lobes. These findings indicate that the composition of A and PP cells in pancreatic islets is closely related to the type of duct system.

Animals↗
PubMed1999

Body composition analysis by dual energy X-ray absorptiometry and exercise performance in underweight patients with COPD.

STUDY OBJECTIVES: The aim of this study was to examine the effect of body composition on maximal exercise performance in patients with COPD. METHODS: The study was carried out on 27 patients with COPD and was confirmed by pulmonary function testing. Body composition was measured by dual energy x-ray absorptiometry (DXA). Exercise performance was conducted on a cycle ergometer and was measured as maximal work rate (WRmax) and maximal oxygen uptake (VO2max). Bone mineral content (BMC), lean mass (LEAN), and fat mass (FAT) were assessed by DXA and were expressed as a percentage of ideal body weight, BMC, LEAN, and FAT. RESULTS: LEAN% correlated significantly with VO2max (r = 0.66, p = 0.0002) and WRmax (r = 0.70, p < 0.0001). No significant correlation was found between FAT% and exercise performance. By stepwise regression analysis, variables significantly contributing to WRmax and VO2max were LEAN% and the maximal voluntary ventilation. Total variance explained in these models was 81% for WRmax aid 82% for VO2max. CONCLUSION: Lean mass was an important determinant of maximal exercise performance in patients with COPD.

Absorptiometry, Photon↗
PubMed1999

The suture applicator for replacing a bone flap--technical note.

A new instrument was developed for passing and holding sutures during the replacement of a bone flap. The new device is a simple straight aluminum shaft, 6 cm in length and 0.7 mm in diameter with a groove on both ends for holding the suture. The shaft can be easily bent with the fingers to attain the desired curve and more suitable manipulation. Passing the shaft through the straight hole in the cranium or the cranial flap was very easy and convenient. No dural damage occurred during 80 procedures using this shaft. No needle holder or forceps for temporary clipping sutures were necessary, which reduced the operative time and mental and physical burden on the operator and the nurses. The mean time per hole with our instrument (45.8 +/- 9.2 sec) was significantly shorter compared to conventional methods with a circular needle, needle holder, and many forceps for temporary clamping of sutures (65.6 +/- 13.2 sec).

Bone Transplantation↗
PubMed1999

Effective production of dehydro cyclic dipeptide albonoursin exhibiting pronuclear fusion inhibitory activity. I. Taxonomy and fermentation.

Strain KO-23, an actinomycete producing albonoursin as well as streptopyrone, was identified as Streptomyces albulus by morphological and biochemical studies. Fermentation conditions for albonoursin, a dehydro cyclic dipeptide exhibiting a pronounced inhibitory activity toward pronuclear fusion of sea urchin eggs, were optimized. Under the optimum conditions, the actinomycete produced 16 mg/liter of albonoursin, 30 times higher than that in the original culture. The cells cultivated under these conditions highly express biosynthetic enzymes for albonoursin, and thus are available for biosynthetic studies of dehydro cyclic peptides.

Anti-Bacterial Agents↗
PubMed1999

Anteroposterior and rotational movement of femur during knee flexion.

This study was designed to analyze anteroposterior and rotational movement of femoral condyles during knee flexion from 15 degrees to 90 degrees using magnetic resonance imaging. After a pilot study, scans were made in 10 healthy male Japanese volunteers. When centers of the circular profiles of posterior femoral condyles were used as reference points, the medial and lateral femoral condyles displaced posteriorly 1.9 +/- 0.8 mm and 2.3 +/- 0.5 mm, respectively (mean +/- standard error). Duplicate examinations on two separate occasions revealed the accuracy of this procedure was in the range of 1 to 2 mm. These results have confirmed that femoral rollback occurs in the unloaded normal knee during flexion from 15 degrees to 90 degrees, but its magnitude is small (2 mm). The results obtained in this in vivo measurement of anteroposterior movement of the femoral condyles have relevance for total knee replacement design.

Adult↗
PubMed1999

Deep infection and fracture healing in immediate and delayed locked intramedullary nailing for open femoral fractures.

Fifty-nine patients with 61 open femoral fractures were treated with immediate locked intramedullary (IM) nailing (group 1; n=15), delayed IM nailing following nonoperative treatment (group 2; n=42), and delayed IM nailing following external fixation (group 3; n=7). Sixteen fractures were Gustilo type I, 28 were type II, 7 were type IIIA, 6 were type IIIB, and 4 were type IIIC open fractures. Four (6.6%) deep infections occurred. Significant differences existed in the deep infection rate (DIR) between types I and II and all type III fractures (2.3% for types I and II versus 17.6% for type III). The deep infection rate did not differ significantly among the nailing groups (13.3%, 2.6%, and 15.3% for groups 1, 2, and 3, respectively), nor did the deep infection rate correlate with the degree of fracture comminution, the existence of polytrauma or polyskeletal trauma, or preexistence of superficial or pin-site infections. Seven (11.7%) of these fractures resulted in nonunion, excluding one secondary amputation; the nonunion rate correlated with fracture location. There were no significant differences in the mean fracture healing times between any of the nailing groups. These results suggest that IM nailing for the treatment of type III open femoral fractures should be considered carefully, regardless of whether it is performed immediately or delayed.

Adolescent↗
PubMed1999

[A study of factors relating to aggravation of patients with pulmonary Mycobacterium avium complex disease--with special reference to malnutrition].

We examined physical and blood statuses of 24 patients with pulmonary M. avium complex disease who entered our hospital from April 1993 to March 1997. Ten patients (41.7%) were diagnosed as primary infection type and 14 patients (58.3%) as secondary infection type. Twenty-four patients were classified to the following two groups: Group A was 14 patients who converted to MAC negative within six months after the admission and group B was 10 patients who continued to excrete MAC for more than six months after the admission. We made a comparison between group A and group B as to the results of physical and blood examinations on admission. Mean value of %IBW in group B was significantly lower (group B:74.4 +/- 8.9%, group A:82.9 +/- 12.7%, p < 0.05) than that of group A. The level of serum albumin in group B was significantly lower (group B: 3.39 +/- 0.53 g/dl, group A: 3.99 +/- 0.45 g/dl, p < 0.01) than that of group A. ChE in group B was significantly lower (group B: 321.2 +/- 94.5 IU/l, group A: 442.9 +/- 148.4 IU/l, p < 0.05) than that of group A. Group B was nutritionally depleted than group A. In conclusion, these findings suggested that nutritional support should be taken into consideration in combination with conventional chemotherapy in treating chronic, intractable MAC disease.

Aged↗
PubMed1999

[A case of arteriovenous fistula of the lung].

A 29-year-old male was admitted to our hospital for further evaluation of left sided paresis, cyanosis, clubbing finger. The laboratory data revealed polycythemia and hypoxemia. Cerebralarteriogram showed right middle cerebral artery occulusion. Cardiofunctional test showed atrial fibrillation, lower left ventricular function. Cardiac catheterization, pulmonary arteriography and three dimensions CT were performed. Right to left shunt rate was 20.4%. A single large pulmonary arteriovenous fistura with a feeding artery (A10) and a draining vein (V10) was found clearly. In this cases, arteriovenous fistula was large, blood flow was thought to be rapid. We thought transcatheter embolization was not useful. And we performed right lower lobectomy. Postoperative course was not eventful. Cyanosis disappeared, clubbing finger was cured.

Adult↗
PubMed1999

[Three cases of multiple liver metastases of gastric cancer responding to tegafur/low-dose CDDP/CPT-11 combination chemotherapy].

We report 3 cases of multiple liver metastases of gastric cancer responding to tegafur/low-dose CDDP/CPT-11 combination chemotherapy. One course of the chemotherapeutic regimen consisted of tegafur 1,200 mg/body/24 hr civ (days 1-12) + CDDP 10 mg/body one shot i.v. (days 1-5, 8-12) + CPT-11 100 mg/body one shot i.v. (day 13). The patient underwent 2 courses. The 2nd course was done on days 16-28, and the CPT-11 dose was increased as 125 mg/body. The outcome obtained was a 3 PR response. In general, a poor nutritional state is often seen in cases of multiple liver metastases of gastric cancer. Chemotherapy with low toxicity and high efficacy is required in such cases. Our regimen is an effective means of treatment for both primary lesion of gastric cancer, and multiple liver metastases, allowing a good postchemotherapeutic quality of life.

Adenocarcinoma↗
PubMed1999

Correlation of serum HDL-cholesterol and LCAT levels with the fraction of ionized magnesium in children.

Correlation of serum lipids and apolipoprotein levels with serum total magnesium concentration and whole blood ionized magnesium level was determined in 47 children (14 female and 33 male; mean age, 8.7 +/- 4.2 years). Mean serum concentration of magnesium was 2.19 +/- 0.19 mg/dl, whole blood concentration of ionized magnesium 1.23 +/- 0.08 mg/dl, and fraction of ionized magnesium (ratio of whole blood ionized magnesium to serum total magnesium) 0.56 +/- 0.04. Neither serum total magnesium level nor whole blood ionized magnesium level had any correlation with serum albumin, lipid, and apolipoprotein levels. However, the fraction of ionized magnesium was significantly correlated with HDL-cholesterol (n = 46, r = 0.31, p = 0.0345), apolipoprotein A-1 (n = 41, r = 0.39, p = 0.0124), and lecithin-cholesterol acyltransferase (LCAT) (n = 20, r = 52, p = 0.0184). These results suggest that fraction of ionized magnesium is more closely linked to serum HDL-cholesterol and LCAT level than with the serum total magnesium level or whole blood ionized magnesium.

Apolipoprotein A-I↗
PubMed1999

The life of Dr. Masao Sumita (1878-1946), a founder of modern orthopaedic surgery in Kyushu.

The life of Dr. Masao Sumita, who was the first professor of the Department of Orthopaedic Surgery at Kyushu University in Fukuoka during 1912-1925, was one of the founders of modern orthopaedic surgery in Japan. His technique of operative procedures had gained a national reputation, and the successful results of his operations of arthroplasty in over 300 joints, along with his other enormous academic achievements were reported. However, he was accused of conducting private clinic activities outside the university hospital, which was considered illegal as a national public official. The free attitude to medical practice that he had experienced during his stay in European countries, where conducting private clinic work, even outside the national university was approved, led to this unjustifiable incident in Japan. He was subsequently purged from the university due to this accusation. In his family life he was survived by his wife and four children. His life story seemed to the author to be a drama with rise and fall. Consequently, the author would like to reveal Sumita's outstanding academic achievements and real personal image as an ingenious surgeon and scholar, in spite of the sorrowful aspect of his life.

General Surgery↗
PubMed1998

Measurements of zeta potentials of particulate biomaterials in protein-rich hyaluronan solution with changes in pH and protein constituents.

This study was undertaken to determine the zeta potentials of particulate biomaterials in three types of protein-rich hyaluronan solution with changes in pH; a microelectrophoretic method was used. For the purpose of determining the pH value of synovial fluid in various inflammatory conditions, we collected synovial fluid samples from joints with osteoarthritis (OA), rheumatoid arthritis (RA), and those undergoing revisions arthroplasties. The mean values of the pH in the synovial fluid from joints with OA, RA, and revision arthroplasty were shown to be 7.9, 7.5, and 8.1, respectively. The pH-zeta potential curves obtained differed, depending on the biomaterial and the medium. Addition of gamma-globulin to the medium reduced the absolute value of the zeta potentials of some of the biomaterials. The findings of this study suggest that the electrophoretic behaviors of the particulate biomaterials tested in this study are affected by the protein constituents of and pH changes in protein-rich synovial fluid. The values we obtained will be useful as reference standards and will also aid in the study of the surface phenomena of biomaterials.

Biocompatible Materials↗
PubMed1998

Differential regulation of coproporphyrinogen oxidase gene between erythroid and nonerythroid cells.

Coproporphyrinogen oxidase (CPO) catalyzes the sixth step of the heme biosynthetic pathway. To assess the tissue-specific regulation of the CPO gene promoter, mouse genomic DNA clones for CPO were isolated. Structural analysis demonstrated that the mouse CPO gene spans approximately 11 kb and consists of seven exons, just like its human counterpart. Functional analysis of the promoter by transient transfection assays indicated that synergistic action between an SP-1-like element at -21/-12, a GATA site at -59/-54, and a novel regulatory element, CPRE (-GGACTACAG-) at -49/-41, is essential for the promoter activity in murine erythroleukemia (MEL) cells. In nonerythroid NIH3T3 cells, however, the GATA site is not required. Gel mobility shift assays demonstrated that specific DNA-protein complexes can be formed with each element, and that there are cell-specific differences in factors, which bind to the SP-1-like element between MEL and NIH3T3 cells. These results provide evidence for differential regulation of the promoter function of CPO gene between erythroid and nonerythroid cells.

3T3 Cells↗
PubMed1998

Structure and expression of the mouse AhR nuclear translocator (mArnt) gene.

Aryl hydrocarbon receptor (AhR) nuclear translocator (Arnt) gene has been isolated and characterized from a mouse genomic DNA library. The gene is about 60 kilobases long and split into 22 exons. An unusual exon/intron junctional sequence was found in the 11th intron of the gene that begins with GC at its 5'-end. The exon/intron arrangement of mArnt gene differs greatly from those of the other members of the same basic-helix-loop-helix/PAS family. The gene is TATA-less and has several transcription start sites. The promoter region of the mArnt gene is GC-rich and contains a number of putative regulatory DNA sequences such as two GC-boxes, a cAMP-responsive element, E-box, AP-1 site, and CAAT-box. Deletion experiments revealed that all these DNA elements made substantial contributions to a high level of expression of the gene, except for the cAMP-responsive element. Of all, two GC-boxes displayed the most dominant enhancing effects. It was demonstrated that there exist specific factors binding to these DNA elements in the nuclear extracts of HeLa cells. Among them, Sp1 and Sp3, and CAAT-box binding factor-A were identified to bind the GC-boxes and CAAT-box, respectively. Expression of MyoD in HeLa cells stimulated the Arnt promoter activity by binding to the E-box.

Amino Acid Sequence↗
PubMed1998

Expression of pI(Cln) in Escherichia coli gives a strong tolerance to hypotonic stress.

We amplified the coding region DNA sequence from a rat renal pI(Cln) cDNA by PCR and expressed the protein in Escherichia coli cells. The cells were exposed to hypotonic conditions followed by spreading them onto LB plates for subsequent colony survival assay. The present study demonstrated that the cells expressing pI(Cln) exhibit a strong resistance to hypotonic stress. Moreover, the resistance was specifically inhibited by extracellular ATP and some anion channel inhibitors. These findings indicate that the expression of pI(Cln) directly confers tolerance to hypotonic stress, and pI(Cln) is concluded to be an important molecule for cell-volume regulation.

Adaptation, Biological↗
PubMed1998

Transcriptionally active heterodimer formation of an Arnt-like PAS protein, Arnt3, with HIF-1a, HLF, and clock.

We isolated a cDNA clone encoding a polypeptide of 626 amino acids containing basic helix-loop-helix (bHLH) and PAS domains from a mouse cDNA library of P19 cells. This protein, termed Arnt3, showed the highest similarity to Arnt and Arnt2 in the bHLH and PAS regions. Arnt3 mRNA was expressed in brain, skeletal muscle, 13.5-day embryos, and P19 cells treated with retinoic acid. The partner PAS proteins of Arnt3 were searched for by the two-hybrid system in yeast, and HIF-1 alpha, HLF, and Clock among various bHLH/PAS proteins were found. Gel mobility shift analysis using nuclear extracts from 293T cells cotransfected with Arnt3 and HIF-1 alpha (or HLF) expression plasmids revealed that these complexes specifically bound the hypoxia-response element (HRE). Coexpression of Arnt3 and HIF-1 alpha (or HLF) in Arnt-deficient c4 cells enhanced transcription of a reporter gene driven by the HRE sequences. We also showed that Arnt3 contained an activation domain at the C-terminal region and a repression domain between the PAS-A and PAS-B regions.

ARNTL Transcription Factors↗