PubMed Health⌕ Search

Biomedical subjects

Kenji Kobayashi

Publications and source records attributed to Kenji Kobayashi.

At least 55 records · Page 3Linked to original sources

A genomewide survey of developmentally relevant genes in Ciona intestinalis. IV. Genes for HMG transcriptional regulators, bZip and GATA/Gli/Zic/Snail.

Many kinds of transcription factors and regulators play key roles in a variety of developmental processes. In the present survey, genes encoding proteins with conserved HMG-box, bZip domains, and some types of zinc finger motifs were surveyed in the completely sequenced genome of Ciona intestinalis. In the present analysis, 21 HMG-box-containing genes and 26 bZip genes were identified as well as four small groups of zinc finger genes in the Ciona genome. The results also showed that a less redundant set of genes is present in the Ciona genome compared with vertebrate genomes. In addition, cDNA clones for almost all genes identified have been cloned and distributed as a " Ciona intestinalis Gene Collection Release I". The present comprehensive analysis therefore provides a means to study the role of these transcription factors in developmental processes of basal chordates.

Animals↗

A genomewide survey of developmentally relevant genes in Ciona intestinalis. II. Genes for homeobox transcription factors.

Homeobox-containing genes play crucial roles in various developmental processes, including body-plan specification, pattern formation and cell-type specification. The present study searched the draft genome sequence and cDNA/EST database of the basal chordate Ciona intestinalis to identify 83 homeobox-containing genes in this animal. This number of homeobox genes in the Ciona genome is smaller than that in the Caenorhabditis elegans, Drosophila melanogaster, human and mouse genomes. Of the 83 genes, 76 have possible human orthologues and 7 may be unique to Ciona. The ascidian homeobox genes were classified into 11 classes, including Hox class, NK class, Paired class, POU class, LIM class, TALE class, SIX class, Prox class, Cut class, ZFH class and HNF1 class, according to the classification scheme devised for known homeobox genes. As to the Hox cluster, the Ciona genome contains single copies of each of the paralogous groups, suggesting that there is a single Hox cluster, if any, but genes orthologous to Hox7, 8, 9 and 11 were not found in the genome. In addition, loss of genes had occurred independently in the Ciona lineage and was noticed in Gbx of the EHGbox subclass, Sax, NK3, Vax and vent of the NK class, Cart, Og9, Anf and Mix of the Paired class, POU-I, III, V and VI of the POU class, Lhx6/7 of the LIM class, TGIF of the TALE class, Cux and SATB of the Cut class, and ZFH1 of the ZFH class, which might have reduced the number of Ciona homeobox genes. Interestingly, one of the newly identified Ciona intestinalis genes and its vertebrate counterparts constitute a novel subclass of HNF1 class homeobox genes. Furthermore, evidence for the gene structures and expression of 54 of the 83 homeobox genes was provided by analysis of ESTs, suggesting that cDNAs for these 54 genes are available. The present data thus reveal the repertoire of homeodomain-containing transcription factors in the Ciona genome, which will be useful for future research on the development and evolution of chordates.

Animals↗

Solvent-induced polymorphism of three-dimensional hydrogen-bonded networks of hexakis(4-carbamoylphenyl)benzene.

The crystal structures for three types of three-dimensional (3-D) hydrogen-bonded networks of hexakis(4-carbamoylphenyl)benzene (1), the network morphologies of which depend greatly on crystallization conditions, have been determined. When this compound is crystallized from hot DMSO, the resulting crystals, 1.12DMSO (orthorhombic, Pca2(1)), showed a 3-D hydrogen-bonded porous network (type A) via 1-D catemer chains as a hydrogen-bonding motif of six primary amide groups. The type A network creates chambers surrounded by six molecules of 1 and channels along the c axis to give the highest porosity among the network polymorphs of 1 investigated here. Crystallization from a boiling mixture of n-PrOH and water gave 1.6n-PrOH (monoclinic, P2(1)/c), which exhibits another type of 3-D hydrogen-bonded porous network (type B) via cyclic dimers as another hydrogen-bonding motif of six primary amide groups. The type B network leads to triangle-like channels along the a axis having a cross section of ca. 9.2 x 9.7 x 9.7 A (including van der Waals radii). The crystal structure of 1.H(2)O (monoclinic, P2(1)/c), which was produced under hydrothermal conditions, showed a nonporous 3-D hydrogen-bonded network chain of amide groups (type C) composed of a mixed hydrogen bonding motif of helical catemer chains/cyclic dimer/catemer. Solvent-induced topological isomerism of these 3-D hydrogen-bonded networks of 1 arises from (i) the guest inclusion ability based on a radially functionalized hexagonal structure of 1, (ii) the correlation between the hydrogen bond donor ability of the syn and anti protons of the primary amide group in host 1 and the hydrogen bond acceptor ability of the oxygen atoms of 1 and guest solvents, and (iii) the polarity of the bulk crystallization solvents.

Journal Article↗

Skeletal effects of erythropoietin in hemodialysis patients.

AIMS: To assess the effects of erythropoietin (EPO) on bone metabolism in patients receiving chronic hemodialysis (HD). METHODS: Forty one patients were divided into two groups whether they required the administration of EPO to treat renal anemia or not. Serial measurements of predialysis blood samples and bone mineral density were performed prospectively over a year. RESULTS: The administration of EPO was associated with an increased serum creatinine (11.9 +/- 0.4 to 12.5 +/- 0.4 mg/dl, p < 0.05), insulin-like growth factor binding protein (3.0 +/- 0.2 to 3.4 +/- 0.2 micrograms/ml, p < 0.05) as well as decreased iron level (112 +/- 7 to 88 +/- 7 micrograms/dl, p < 0.005). Furthermore, in EPO-treated group, exogenous EPO doses correlated with the increments in 1,25-dihydroxy-vitamin D (r = 0.38, p < 0.05), intact osteocalcin (r = 0.42, p < 0.05) and bone alkali-phosphatase (r = 0.53, p < 0.005), but not intact parathyroid hormone (r = 0.09). Both metacarpal index (0.47 +/- 0.02 to 0.47 +/- 0.02) and the summation of gray scale/diameter (2.68 +/- 0.06 to 2.61 +/- 0.07 mmAl), bone mineral density parameters, remained unchanged. CONCLUSION: The present data provide evidence that EPO may modulate the production of 1,25-dihydroxy-vitamin D in HD patients. Furthermore, our findings suggest that EPO therapy activates insulin-like growth factor system in HD patients, possibly through its actions on metabolism.

Analysis of Variance↗

Prognostic value of nonlinear heart rate dynamics in hemodialysis patients with coronary artery disease.

BACKGROUND: Although altered nonlinear heart rate dynamics predicts death in patients with coronary artery disease (CAD), its prognostic value in chronic hemodialysis patients with CAD is unknown. METHODS: We analyzed 24-hour electrocardiogram for nonlinear heart rate dynamics and heart rate variability in a retrospective cohort of 81 chronic hemodialysis patients with CAD. RESULTS: During a follow-up period of 31 +/- 20 months, 19 cardiac and 8 noncardiac deaths were observed. Cox hazards model, including diabetes, left ventricular ejection fraction, and the number of diseased coronary arteries, revealed that abnormal alpha2 (defined as both increase and decrease in alpha2 because of its J curve relationship with cardiac mortality), decreased approximate entropy and decreased heart rate variability (triangular index and ultra-low frequency power) were significant and independent predictors of cardiac death. No significant and independent predictive power for noncardiac death was observed in either the heart rate dynamics or the heart rate variability measures. The predictive power of alpha2 and approximate entropy was independent of that of triangular index and ultra-low frequency power. Combinations of two categories of measures improved the predictive accuracy; overall accuracy of approximate entropy + ultra-low frequency power for cardiac death was 87%. CONCLUSION: Altered nonlinear heart rate dynamics are independent predictors of cardiac death in chronic hemodialysis patients with CAD and their combinations with decreased heart rate variability provide clinically useful markers for risk stratification.

Aged↗

Suppression of macho-1-directed muscle fate by FGF and BMP is required for formation of posterior endoderm in ascidian embryos.

Specification of germ layers is a crucial event in early embryogenesis. In embryos of the ascidian, Halocynthia roretzi, endoderm cells originate from two distinct lineages in the vegetal hemisphere. Cell dissociation experiments suggest that cell interactions are required for posterior endoderm formation, which has hitherto been thought to be solely regulated by localized egg cytoplasmic factors. Without cell interaction, every descendant of posterior-vegetal blastomeres, including endoderm precursors, assumed muscle fate. Cell interactions are required for suppression of muscle fate and thereby promote endoderm differentiation in the posterior endoderm precursors. The cell interactions take place at the 16- to 32-cell stage. Inhibition of cell signaling by FGF receptor and MEK inhibitor also supported the requirement of cell interactions. Consistently, FGF was a potent signaling molecule, whose signaling is transduced by MEK-MAPK. By contrast, such cell interactions are not required for formation of the anterior endoderm. Our results suggest that another redundant signaling molecule is also involved in the posterior endoderm formation, which is likely to be mediated by BMP. Suppression of the function of macho-1, a muscle determinant in ascidian eggs, by antisense oligonucleotide was enough to allow autonomous endoderm specification. Therefore, the cell interactions induce endoderm formation by suppressing the function of macho-1, which is to promote muscle fate. These findings suggest the presence of novel mechanisms that suppress functions of inappropriately distributed maternal determinants via cell interactions after embryogenesis starts. Such cell interactions would restrict the regions where maternal determinants work, and play a key role in marking precise boundaries between precursor cells of different tissue types.

Animals↗

Risk stratification of adult pneumonia in a tertiary emergency center in Japan.

OBJECTIVE: To determine whether the guidelines for community-acquired pneumonia published by the Infectious Disease Society of America (IDSA) and the Japanese Respiratory Society (JRS) are applicable to stratifying the mortality risk of patients visiting a tertiary emergency center in Japan. METHODS: Patients were categorized into three risk groups (low, intermediate and high) based on the IDSA guidelines and three severity groups (mild, moderate and severe) using the JRS guidelines. The mortality rates among each set of groups were then compared using 30-day follow-up data. PATIENTS: Ninety-seven consecutive patients with pneumonia who visited the emergency room and were admitted to our hospital were retrospectively identified. RESULTS: Based on the IDSA guidelines, the patients were categorized into a high, intermediate, or low-risk group (38.1%, 51.5% and 10.3%, respectively). Cumulative mortality rates were 18.9% for the high-risk group and 4.0% for the moderate-risk group (p=0.02); no deaths occurred in the low-risk group. Based on the JRS guidelines, the patients were also classified into a severe, moderate, or the mild-severity group (69.1%, 25.8% and 5.2%, respectively). The mortality rate was 13.4% in the severe group, whereas no deaths occurred in the moderate or mild-severity groups. CONCLUSION: The IDSA and JRS guidelines allow short-term mortality risks to be recognized at a tertiary emergency center in Japan.

Adult↗

Vesico-ileosigmoidal fistula caused by diverticulitis: report of a case and literature review in Japan.

Enterovesical fistula is a relatively uncommon complication of colorectal and pelvic malignancies, diverticulitis, inflammatory bowel disease, radiotherapy, and trauma in Asian countries. A case of vesico-ileosigmoidal fistula and a literature review of this disease in Japan are presented. A 70-yr-old male was referred with complaints of urinary pain and pneumaturia. On admission, urinary tract infection and pneumaturia were presented. A barium enema demonstrated multiple diverticulum in his sigmoid colon and the passage of contrast medium into the bladder and ileum. Under the diagnosis of vesico-ileosigmoidal fistula due to suspected diverticulitis of the sigmoid colon, sigmoidectomy and partial resection of the ileum with partial cystectomy were performed. The histopathology revealed diverticulosis of the sigmoid colon with diverticulitis and development of a vesico-ileosigmoidal fistula. No malignant findings were observed. Until the year 2000, a total of 173 cases of vesico-sigmoidal fistula caused by diverticulitis had been reported in Japan. Pneumaturia and fecaluria are the most common types, presenting symptoms in 63% of the cases. Computed tomography, with a sensitivity of 40% to 100%, is the most commonly used diagnostic study. For patients with vesico-sigmoidal fistula, resection of the diseased sigmoid colon and partial cystectomy with primary anastomosis are the safest and most acceptable procedures, leading to the best results.

Aged↗

The draft genome of Ciona intestinalis: insights into chordate and vertebrate origins.

The first chordates appear in the fossil record at the time of the Cambrian explosion, nearly 550 million years ago. The modern ascidian tadpole represents a plausible approximation to these ancestral chordates. To illuminate the origins of chordate and vertebrates, we generated a draft of the protein-coding portion of the genome of the most studied ascidian, Ciona intestinalis. The Ciona genome contains approximately 16,000 protein-coding genes, similar to the number in other invertebrates, but only half that found in vertebrates. Vertebrate gene families are typically found in simplified form in Ciona, suggesting that ascidians contain the basic ancestral complement of genes involved in cell signaling and development. The ascidian genome has also acquired a number of lineage-specific innovations, including a group of genes engaged in cellulose metabolism that are related to those in bacteria and fungi.

Alleles↗

Malignant melanoma of the anorectum: report of four cases.

Four cases of anorectal malignant melanoma are reported in this paper. All patients underwent an abdominoperineal resection with lymph node dissection for a curative operation and received postoperative chemotherapy with dacarbazine, ranimustine, and vincristine, either with or without interferon-beta. One of these patients has been observed for more than 6 years postoperatively without any evidence of recurrence. The other three patients had advanced diseases at the time of diagnosis, and died within 3 years after operation. The prognosis of anorectal malignant melanoma is considered to be directly related to tumor size and depth. Therefore, a staging system and treatments based on the tumor size and depth (or thickness) are needed.

Aged↗

Serum cartilage-derived retinoic acid-sensitive protein (CD-RAP) levels in swarm rat chondrosarcoma.

Cartilage-derived retinoic acid-sensitive protein (CD-RAP) is a new protein that was isolated from bovine articular chondrocytes and human melanoma cell lines (melanoma inhibitory protein or MIA). In normal tissue its expression is limited to cartilage, and in morbid tissue to melanoma, chondrosarcoma, and breast cancer. Serum levels of CD-RAP/MIA correlate with the progression of malignant melanoma, but there have been no reports on chondrosarcoma. Here, it was first demonstrated by RT-PCR and immunohistological methods that CD-RAP was expressed in tissue from a Swarm rat chondrosarcoma that was used as an experimental model. The course following tumor transplantation and changes in serum CD-RAP after tumor excision were then observed to investigate whether serum CD-RAP could be used as a marker of tumor activity. Consequently, serum CD-RAP in control rats tended to decrease as the animal grew, whereas it rose in proportion to tumor proliferation in rats that had received a tumor graft. Serum CD-RAP levels dropped rapidly following excision of the tumor in a group of tumor-excised rats. In those rats which had a recurrence following excision of the tumor, serum CD-RAP rose prior to the appearance of the tumor. Serum CD-RAP thus sensitively reflected tumor onset and proliferation, so that it appeared to be an effective marker of tumor activity for Swarm rat chondrosarcoma.

Animals↗

A prospective evaluation of outcome in patients referred for PEG placement.

BACKGROUND: PEG feeding is not recommended for short-term use because the 30-day mortality after PEG placement is substantial. The primary aim of this study was to prospectively identify factors predictive of survival in patients referred for PEG placement. METHODS: All patients for whom gastroenterology consultation was sought for feeding PEG placement were prospectively studied. Demographic data, Charlson comorbidity index, and functional status were recorded at entry. After PEG placement, patients were followed for up to 12 months. RESULTS: Of the 67 patients for whom consultation was requested, 58 were eligible for the study and 50 underwent PEG placement. The 7-day and 30-day mortality rates in the PEG placement group were 4% and 20%, respectively. In multivariate analysis, only the Charlson index > or =4 was associated with decreased survival time (relative hazard = 2.9: 95% CI [1.20, 7.21], p = 0.019). Median survival in patients with Charlson comorbidity index > or =4 was significantly shorter than that in patients with Charlson index < 4 (p = 0.013). CONCLUSIONS: A Charlson comorbidity index > or =4 was significantly associated with shorter patient survival after initial consultation. Careful consideration of predictive factors of survival may improve patient selection for feeding PEG placement.

Aged↗

Afebrile scrub typhus (Tsutsugamushi disease) with acute respiratory distress syndrome.

A 74-year-old Japanese man with scrub typhus presented without the typical symptom of high fever and subsequently developed the complication of acute respiratory distress syndrome. It was suspected that exposure occurred at the river side of Kinugawa, Tochigi Prefecture, Japan. His body temperature was below 38.0 degrees C. After intensive supportive care and minocycline therapy, he dramatically recovered. With the increase in popularity of outdoor recreation, scrub typhus can be found in clinics all over Japan. Physicians should therefore be aware of the manifestations of the disease and the necessity of early treatment in suspected cases.

Aged↗

Glomerular and serum IgG subclasses in diffuse proliferative lupus nephritis, membranous lupus nephritis, and idiopathic membranous nephropathy.

OBJECTIVE: To determine whether a different renal histopathology is associated with the characteristic IgG subclass distribution, and whether a distinct IgG subclass distribution is involved in a unique immunopathological expression, we compared the distributions of glomerular and serum IgG subclasses in diffuse proliferative lupus nephritis (DPLN), membranous LN (MLN), and idiopathic membranous nephropathy (MN). PATIENTS AND METHODS: The glomerular IgG subclass distributions in patients with DPLN (n=7), MLN (n=10) or MN (n=16) were assessed by direct immunofluorescence microscopy. Serum levels of each IgG subclass were quantitated by ELISA in DPLN, MLN, and MN patients, and in normal human sera (NHS) (n=14). RESULTS: IgG1, IgG2, IgG3, and, to a lesser degree, IgG4 were similarly present in glomerular deposits in both DPLN and MLN. In contrast, IgG4 was the predominant glomerular IgG subclass in MN. Regarding the serum IgG subclasses, the mean IgG subclass concentrations and the mean proportion of each IgG subclass to the total IgG (%IgG subclass) in DPLN and MLN were not significantly different from those in NHS, except for the increased %IgG1 in MLN. In MN, the mean %IgG4 was selectively increased (p<0.01 vs NHS) in association with a slightly elevated IgG4 concentration; however, the mean concentrations of other IgG subclasses were significantly decreased (p<0.01 vs NHS), and the %IgG subclasses were not significantly different from those in NHS. CONCLUSIONS: The results indicate that the IgG subclass distribution is not associated with the different renal histopathologies of DPLN and MLN. This study also shows the selective significance of IgG4 in MN, but not in MLN, another form of membranous glomerulopathy.

Adolescent↗

Cytokine expressions and H. pylori-associated gastric mucosal lesion.

To determine the role of host genetic factors in Helicobacter pylori infection, we examined the relation between gastroduodenal diseases and IL-1B polymorphisms in patients with H. pylori infection. In addition, we also compared gastric mucosal cytokine levels in those patients. We confirmed the findings that the IL-1B-31 C-to-T base transition was inverted in association with the -511 T-to-C base transition. There was no relation regarding to IL-1B polymorphisms and clinical outcomes. The gastric mucosal IL-1B level of the body of the stomach but not the antrum was significantly different among IL-1B genotypes. Furthermore, the IL-8 levels in the body were also higher in IL-1B-511C/C/ IL-1B-31TT than H. pylori negative patients. These findings suggested that IL-1B polymorphisms enhance not only IL-1-B production but also IL-8 production in the gastric body and may play an important role in the development of atrophic gastritis.

Cytokines↗

[Adjuvant chemotherapy after curative resection for gastric cancer-5'-DFUR + cisplatin vs 5'-DFUR].

A prospective randomized study involving gastric cancer patients was conducted to evaluate combined adjuvant chemotherapy. Forty-two patients under 80 years of age who underwent a curative resection of pathologic stage II or III gastric cancer were randomly assigned to receive adjuvant chemotherapy containing the following two regimens from 1993 to 1996. A) Oral 5'-deoxy-5-fluorouridin (5'-DFUR) plus cisplatin: 5'-DFUR, daily administration, combined with CDDP 15 mg/m2/day, 30-min drip infusion, fortnightly for 8 weeks, repeated every 16 weeks. B) Oral 5'-DFUR alone: 5'-DFUR, daily administration. The dosages of 5'-DFUR were assigned according to the patients' body surface area (BSA): BSA < 1.7 m2, 600 mg and BSA > or = 1.7 m2, 800 mg, daily administration, bid. Twenty patients were assigned to regimen A, and 22 to regimen B. All clinicopathological factors were equally distributed in each regimen. No adverse reactions greater than grade 3 occurred in either regimen. There was no significant difference between the two regimens in overall survival or overall disease-free survival. For patients with positive nodes, the 5-year disease-free survival rates were 56.4% in A and 38.3% in B (p = 0.29). In stage III patients, the 5-year disease-free survival rates were 55.6% in A and 20.7% in B (p = 0.26). No significant survival benefit was observed with the combined chemotherapeutic regimen, 5'-DFUR plus cisplatin, compared with 5'-DFUR alone.

Adult↗

Remote Pummerer Reaction via Intermolecular Through-Space Interaction between Sulfonium and Sulfenyl Sulfur Atoms.

The remote Pummerer reaction of the mono-sulfoxide of p-bis(methylthio)-aromatic 1 is described. The reaction of 1 with (CF(3)CO)(2)O in CH(2)Cl(2) gave a mixture of the corresponding mono-Pummerer product 2, the bis-Pummerer product 3, and the bis-sulfide 4 in an n:1:1 ratio (n >/= 2). The 1:1 formation of 3 and 4 indicates an intermolecular interaction between sulfur atoms. The reaction with the deuterium-labeled 1-d(3)() showed that the formation of 2 occurs at the sulfenyl as well as sulfinyl groups in 1a-d(3)()-1d-d(3)(), in which the product ratio of 2-d(3)():2-d(2)() is in the range of 3.5-10. On the other hand, the Pummerer reaction of 1e-d(3)() occurred preferably at the sulfinyl group in a usual manner. The reaction of a 1:1 mixture of the bis-sulfide 4 and the bis-sulfoxide 5 with (CF(3)CO)(2)O also gave 2, 3, and 4 in a ratio similar to that for the reaction of 1. The mechanism in the present remote Pummerer reactions is discussed in light of an intermolecular through-space interaction between the sulfonium and sulfenyl sulfur atoms, and a dithia dication dimer B and/or a bis(dithia dication) cyclic dimer C are proposed as intermediates.

Journal Article↗