Search PubMed⌕ Search

Biomedical subjects

K Okabayashi

Publications and source records attributed to K Okabayashi.

At least 19 recordsLinked to original sources
PubMed2004

mRNA expression and protein localization of dentin matrix protein 1 during dental root formation.

Dentin matrix protein 1 (DMP1) is an acidic phosphoprotein. DMP1 was initially detected in dentin and later in other mineralized tissues including cementum and bone, but the DMP1 expression pattern in tooth is still controversial. To determine the precise localization of DMP1 messenger RNA (mRNA) and the protein in the tooth, we performed in situ hybridization and immunohistochemical analyses using rat molars and incisors during various stages of root formation. During root dentin formation of molars, DMP1 mRNA was detected in root odontoblasts in parallel with mineralization of the dentin. However, the level of DMP1 mRNA expression in root odontoblasts decreased near the coronal part and was absent in coronal odontoblasts. DMP1 protein was localized along dentinal tubules and their branches in mineralized root dentin, and the distribution of DMP1 shifted from the end of dentinal tubules to the base of the tubules as dentin formation progressed. During the formation of the acellular cementum, DMP1 mRNA was detected in cementoblasts lining the acellular cementum where its protein was localized. During the formation of the cellular cementum, DMP1 mRNA was detected in cementocytes embedded in the cellular cementum but not in cementoblasts, and its protein was localized in the pericellular cementum of cementocytes including their processes. During dentin formation of incisors, DMP1 mRNA was detected in odontoblasts on the cementum-related dentin, where its protein was localized along dentinal tubules near the mineralization front. The localization of DMP1 mRNA and protein in dentin and cementum was related to their mineralization, suggesting that one of the functions of DMP1 may be involved in the mineralization of dentin and cementum during root formation.

Animals↗
PubMed2003

Laparoscopic surgery for recurrent Crohn's disease.

BACKGROUND: The aim of this study was to assess the feasibility of laparoscopic surgery for recurrent Crohn's disease, and the role of repeated laparoscopy in reoperation. METHODS: Between January 1994 and May 2002, 61 laparoscopic operations were attempted in 52 patients with ileal or ileocolonic Crohn's disease. Of these, 16 procedures were performed for recurrence at the anastomotic site (recurrent group). The remaining 45 operations were performed as primary procedures (control group). The median follow-up was 48 (range 3-90) months. RESULTS: The median time to reoperation was 46 months. The incidence of enteric fistula and the conversion rate did not differ significantly between the two groups. Although the operating time was significantly longer in the recurrent group, there were no differences in the rate of postoperative complications (three in the recurrent group and six in the control group) and hospital stay (both median 8 days). CONCLUSION: Laparoscopic surgery for recurrent Crohn's disease is feasible in selected patients without an increase in conversion rate or postoperative complications.

Adolescent↗
PubMed2001

Obliterative airway disease and graft stenting in pig-to-dog tracheal xenotransplantation.

OBJECTIVE: Obliterative airway disease occurring in concordant tracheal xenografts in rodent models is histologically similar to obliterative bronchiolitis in human lung allografts. We studied whether obliterative airway disease would occur in a large animal-discordant model. METHODS: Pig and dog tracheas were cryopreserved for 7 to 14 days, and 18 recipient dogs given splenectomy 7 days before transplantation, then seven tracheal rings were removed and a corresponding five-ring donor tracheal segment was transplanted to the excised site. Grafts were wrapped with pedicled omentum and inmmunosuppression was conducted with tacrolimus or deoxyspergualin. Graft status was observed by bronchoscopy. Dogs were classified into three groups. Group 1 consisted of dog-to-dog allotransplantation animals (control group, n = 5), Group 2 of pig-to-dog xenotransplantation animals (n = 8), and Group 3 of pig-dog xenotransplantation animals who also underwent graft stenting immediately after transplantation (n = 5). RESULTS: Grafts healed well in 4 of 5 Group 1 dogs. Tracheal stricture began on day 5 post transplantation and the lumen was obstructed by fibrosis by days 8 to 14 in all Group 2 dogs. All Group 3 dogs remained in good respiratory status until death. CONCLUSION: Obliterative airway disease developed quickly in pig-to-dog discordant tracheal xenografts. Graft stenting is a feasible treatment for managing of tracheal obstruction.

Airway Obstruction↗
PubMed2001

Analysis of various treatments for pulmonary aspergillomas.

The objective of this study was to analyze the results of various treatments for pulmonary aspergilloma and to determine the surgical indications. A total of 41 patients with pulmonary aspergilloma hospitalized at the National Minamifukuoka Chest Hospital between 1973 and 1999 were analyzed with regard to their response to treatment and long-term prognosis. Five asymptomatic patients who were untreated demonstrated no change in the clinical status of aspergilloma. Analysis of the short-term response revealed surgery to be the most effective treatment. Systemic and intracavitary injections of antifungal drugs were not definitely effective, although they had a positive effect in some patients. A survival analysis revealed that all eight patients who underwent surgery are still alive. Using the Cox proportional hazard model, it was found that the favorable prognostic factors were the absence of symptoms, the absence of a superimposed bacterial infection, and surgery. There were ten deaths: three from lung cancer and seven related to uncontrollable superimposed bacterial infections, often resulting in hemoptysis. We conclude that patients with asymptomatic pulmonary aspergillomas should be clinically observed for signs of the development of lung cancer, but do not require active treatment. On the other hand, patients who are symptomatic and have uncontrollable superimposed bacterial infection will benefit from surgery.

Aged↗
PubMed2001

Expression of ubiquitin gene in Microsporum canis and Trichophyton mentagrophytes cultured with fluconazole.

The expression of the ubiquitin (Ub) gene in dermatophytes was examined for its relation to resistance against the antifungal drug fluconazole. The nucleotide sequences and the deduced amino acid sequences of the Ub gene in Microsporum canis were proven to be 99% similar to those of the Ub gene in Trichophyton mentagrophytes. Expression of mRNA of Ub in M. canis and T. mentagrophytes was enhanced when the fungi were cultured with fluconazole. The antifungal activity of fluconazole against these dermatophytes was increased in the presence of Ub proteasome inhibitor.

Amino Acid Sequence↗
PubMed2001

Characteristic magnetic resonance imaging for neurological assessment in HELLP syndrome with eclampsia: a case report.

HELLP syndrome is a complication of pregnancy characterized by hemolytic anemia, elevated liver enzymes, and low platelets. We describe a patient who suffered a generalized tonic seizure as a clinical onset. Magnetic resonance imaging (MRI) of the brain showed high intensity lesions on T2-weighted images and low- and iso- intensity on T1-weighed images. The patient fully recovered and on follow-up MRI the abnormal lesions were almost totally resolved. The sensitivity and specificity of MRI is useful in distinguishing this complication of pregnancy from cerebral apoplexy, brain tumor, epilepsy and other causes.

Adult↗
PubMed2001

The volume limit in fluid resuscitation to prevent respiratory failure in massively burned children without inhalation injury.

We evaluated the accurate fluid requirement to prevent respiratory failure during the postresuscitation period in the resuscitation of massively burned children without inhalation injury. Forty-nine children were treated by similar fluid resuscitation and physiologic support protocols. Using a retrospective chart review, the children were divided into three groups as follows: Group N (no lung injury, n = 33, 41.4+/-18.7%TBSA burned), Group M (mild-to-moderate lung injury, n = 11, 73.7+/-17.1%TBSA burned) and Group S (severe lung injury, n = 5, 67.2+/-16.6%TBSA burned). Information about fluid resuscitation during the first 24 hr post-injury was collected and compared among the three groups. There was no significant difference in the hourly urine output and the resuscitation volume estimated by body weight and burn size among the groups. The volumes estimated by ml/kg/%TBSA burned were 7.0 ml/kg/%TBSA burned, 8.0 ml/kg/%TBSA burned, and 9.4 ml/kg/%TBSA burned in Groups N, M, and S, respectively. According to the fluid volume estimated by the burn index (BI; 1/2 of % second-degree burns plus % third-degree burns), the volumes were 13.8+/-4.0 ml/kg/BI, 14.4+/-4.4 ml/kg/BI, 18.8+/-3.7ml/kg/BI in Groups N, M, and S, respectively (Group N < Group S, p < 0.05). There was a significant positive correlation between the maximum respiratory index (AaDO2/PaO2) during the first week and the initial total volume administered (ml/kg/BI). These findings indicated that the fluid requirements to prevent postresuscitation respiratory failure in massively burned children might be estimated according to the depth of burned area in addition to body weight and burn size.

Blood Proteins↗
PubMed2001

[Result of surgical treatment to early stage peripheral non-small cell lung cancer].

In the lung cancer, the announcement of the definition, the clinical behavior and the treatment result of the central early stage lung cancer, especially in situ lung cancer, have been seen. However, the definition and a clinicopathological concept of the peripheral lung cancer are still uncertain. The so-called small lung cancer of the tumor diameter 20 mm or less are peripheral lung adenocarcinoma. These patients' prognosis is excellent better, in contradiction to the prognosis of the patients with positive for pleural involvement or vessels invasion is worse. We studied the clinicopathological features, the Noguchi's classification, and prognosis of the 101 patients with small lung adenocarcinoma which were performed the operation, and refere about the selection of the operation method including the VATS and the limited operation.

Adult↗
PubMed2000

Lymph node metastasis and prognosis in small peripheral non-small-cell lung cancers.

OBJECTIVE: The lymph node dissection and curative resection for small peripheral non-small-cell lung cancers, it is essential to know the incidence and distribution of lymph node metastasis to confirm the pathological stage. METHODS: Between January 1984 and August 1996, lobectomy with systemic mediastinal dissection (standard lobectomy) was conducted in 49 patients with small peripheral non-small-cell lung cancers (2.0 cm or less in diameter), and limited resection was conducted in 15 with cardiopulmonary insufficiency. RESULTS: Lymph node metastasis was confirmed histologically in 14 patients undergoing standard lobectomy (28.6%). The incidence of lymph node metastasis was high in tumors with pleural (p2) or subpleural (p1) involvement (63.6%) (7/14). The 5-year survival between standard lobectomy and limited resection patients (83% vs. 71%) was not statistically significant. In patients undergoing standard lobectomy, survival in those with node-negative disease was better than in those with node-positive disease (94% vs. 44%, p < 0.01). CONCLUSIONS: Lymph node involvement, especially in tumors with pleural involvement, is not uncommon, even when tumors are 2.0 cm or less in diameter. Systemic hilar and mediastinal dissection is therefore required for disease staging and treatment.

Aged↗
PubMed2000

Evaluation of the malignant grade of thymic epithelial tumors according to the epithelial subclassification.

We investigated the clinicopathological correlations among 49 surgically resected thymic epithelial tumors (TET), which were subclassified according to the six subtypes established by the Marino, Kirchner, and Müller-Hermelink system, which were renamed as follows: spindle cell type (medullary thymoma), mixed spindle and polygonal cell type (mixed medullary and cortical thymoma), small polygonal cell type (predominantly cortical thymoma), large polygonal cell type (cortical thymoma), atypical type (well differentiated thymic carcinoma), and cytologically malignant type (high-grade thymic carcinoma). The related categories were grouped for statistical analysis as follows: group 1, spindle cell type and mixed type; group 2, small polygonal cell type and large polygonal cell type; group 3, atypical type; group 4, cytologically malignant type. The association of each group with the presence of myasthenia gravis, tumor stage, and the length of survival was studied. Myasthenia gravis was significantly present in patients with small polygonal type, large polygonal type, and atypical type tumors (groups 2 and 3) (P = 0.003). The tumors in group 1 showed the lowest tumor stage while those of group 4 had the most advanced tumor stage (P = 0.002). The patients in group 4 had the worst prognosis, followed by those in group 3, 2, and 1, in that order. The differences among these groups were statistically significant (P = 0.0003). From our results, we determined that TET can be separated into an extremely low-grade malignancy group (group 1), a low-grade malignancy group (group 2), an intermediate malignancy group (group 3), and a high-grade malignancy group (group 4).

Epithelial Cells↗
PubMed2000

The evolutionarily conserved porcupine gene family is involved in the processing of the Wnt family.

The Drosophila segment polarity gene product Porcupine (Porc) was first identified as being necessary for processing Wingless (Wg), a Drosophila Wnt (Wnt) family member. Mouse and Xenopus homologs of porc (Mporc and Xporc) were identified and found to encode endoplasmic reticulum (ER) proteins with multiple transmembrane domains. In contrast with porc, four different types of Mporc and Xporc mRNA (A-D) are generated from a single gene by alternative splicing. Mporc mRNA is differentially expressed during embryogenesis and in various adult tissues, demonstrating that the alternative splicing is regulated to synthesize the specific types of Mporc. In transfected mammalian cells, all Mporc types affect the processing of mouse Wnt 1, 3A, 4, 6, and 7B but not 5A. Furthermore, all Mporc types are co-immunoprecipitated with various Wnt proteins. These results suggest that Mporc may function as a chaperone-like molecule for Wnt. Interestingly, all Mporc types can substitute for Porc, as they are able to rescue the phenotypes of Drosophila porc embryos. Consistent with this observation, Mporc, like Porc, modifies the processing of Wg expressed in mammalian cells. These results demonstrate that the porc gene family encodes the multitransmembrane ER proteins, which are evolutionarily well conserved and involved in processing the Wnt family.

Acyltransferases↗
PubMed2000

Differences among chitin synthase I gene sequences in Trichophyton rubrum and T. violaceum.

Nucleotide sequences of chitin synthase 1 (CHS1) gene were analysed for the phylogenetic relation between Trichophyton violaceum and T. rubrum, including two isolates of T. raubitschekii and one isolate of T. rubrum var. nigricans. About 620-bp genomic DNA fragments of the CHS1 gene were amplified from these dermatophytes by polymerase chain reaction (PCR) and sequenced. The CHS1 nucleotide sequences of these dermatophytes showed more than 95% similarity between the species. The phylogenetic analysis of their sequences revealed that T. rubrum was genetically distinct from T. violaceum. The specific restriction endonuclease site for HinfI was present in the CHS1 gene sequence of T. rubrum but not in that of T. violaceum. A molecular analysis of CHS1 genes will provide useful information for the identification of these Trichophyton species and the understanding of their evolution.

Animals↗
PubMed1999

A novel human gene encoding HECT domain and RCC1-like repeats interacts with cyclins and is potentially regulated by the tumor suppressor proteins.

Cyclin E-Cdk2 is an evolutionary conserved cyclin-dependent kinase (CDK) complex that drives the G1 to S phase transition of the cell cycle. A novel cDNA encoding a HECT family protein also containing RCC1-like repeats was isolated by a yeast two-hybrid screening using both cyclin E and its inhibitor p21. The protein product of this cDNA, Ceb1, interacts with various cyclin subunits of CDKs in mammalian cells. Expression of Ceb1 is specifically detected in testis and ovary and is highly elevated when the functions of the tumor suppressor proteins, p53 and RB, are compromised by mutations or viral oncoproteins. The present results suggest that Ceb1 may play a critical role when its expression and the CDK activity are upregulated by inactivation of p53 and RB.

Amino Acid Motifs↗
PubMed1999

Covalent modification of all members of human cullin family proteins by NEDD8.

Recently we found that NEDD8, a ubiquitin-like protein, was linked covalently to human cullin-4A (abbreviated Cul-4A) by a new ubiquitin-related pathway that is analogous to but distinct from the ligating system for SUMO1, another ubiquitin-like protein. However, it remained unknown whether the other five members of the family of human cullin/Cdc53 proteins are modified by NEDD8. Here we report that all Hs-Cul family proteins, such as Cul-1, Cul-2, Cul-3, Cul-4B, and Cul-5, in addition to Cul-4A, were modified by covalent attachment of NEDD8 in rabbit reticulocyte lysates. Moreover, by comprehensive Northern-blot analyses, we examined multiple tissue distributions of the messages for all Cul-family proteins, NEDD8, and the NEDD8-ligating system consisting of APP-BP1/hUba3, and hUbc12, which function as E1- and E2-like enzymes, respectively. The expressions of Cul-1, Cul-2, and Cul-3 resembled each other and were apparently correlated to those of NEDD8 and the NEDD8-ligating system in various human cells and tissues. However, the mRNA levels of Cul-4A, Cul-4B, and Cul-5 differed considerably from each other as well as from other Cul-family proteins. The enhanced expression of all Cul-family proteins except Cul-5 was observed in a variety of tumor cell lines.

Cell Cycle Proteins↗
PubMed1999

Adjuvant mitomycin and fluorouracil followed by oral uracil plus tegafur in serosa-negative gastric cancer: a randomised trial. Gastric Cancer Surgical Study Group.

BACKGROUND: To study the survival benefit of adjuvant chemotherapy in gastric cancer, seven cancer centres in Japan carried out a phase III clinical trial of adjuvant chemotherapy after curative gastrectomy for macroscopically serosa-negative gastric cancer. METHODS: 579 patients were enrolled in the study, stratified by disease stage (T1, n=188; T2, n=323), and allocated randomly adjuvant chemotherapy or no further treatment. 285 of 288 cases in the treatment group and 288 of 291 in the control group were eligible. Six cases were excluded because they did not fulfill the entry criteria. The treatment group had intravenous mitomycin (1.4 mg/m2) and fluorouracil (166.7 mg/m2) twice weekly for 3 weeks after surgery, and oral UFT (uracil plus tegafur, 300 mg daily) for 18 months. Analyses were by intention to treat. FINDINGS: No serious toxic effects were observed in the treatment group. At median follow-up of 72 months, 59 patients in the control group and 47 in the treatment group had died. There was no significant difference in survival between the groups (5-year survival 82.9% control vs 85.8% treated; hazard ratio 0.738 [95% CI 0.498-1.093]). 5-year survival of patients with T1 (mucosal or submucosal) cancer in the control and treatment groups was 94.9% versus 92.0%, and that of patients with T2 (muscularis propria or subserosa) cancer was 76.9% versus 83.0%. However, a test for heterogeneity and interaction over T1 and T2 subgroups revealed no significant difference in terms of drug response. INTERPRETATION: There was no survival benefit with this adjuvant therapy regimen for patients with macroscopically serosa-negative gastric cancer (T1 and T2) after curative gastrectomy. Patients with T1 cancer can be excluded from future trials, because curative surgery alone yielded a very good survival rate and there seemed no need for adjuvant therapy.

Adenocarcinoma↗
PubMed1999

cDNA cloning and distribution of the Xenopus follistatin-related protein.

Recently, several proteins which have a follistatin module have been isolated. One of them, the follistatin-related protein (FRP), is encoded by TSC-36 (TGF-beta-stimulated clone 36) in mouse, originally isolated as a cDNA clone up-regulated by TGF-beta1 in mouse osteogenic MC3T3E1 cells. To determine the physiological role of FRP in early Xenopus embryonic development, we cloned the Xenopus FRP (xFRP) cDNA. The resulting cDNA clone was a secreted glycoprotein consisting of 299 amino acid residues with about 70% similarity to the mammalian and avian FRPs. Northern blotting analysis revealed that xFRP gene expression started at stage 10, the onset of gastrulation, gradually increased during the blastula and neurula stages and was sustained through the tail-bud stage. Whole-mount in situ hybridization analysis showed the localization of xFRP mRNAs in the Spemann organizer, notochord, neural floor plate, hypochord and somite. The similarities with the pattern of expression of Xenopus follistatin mRNA suggests that xFRP may play a role in neuralization.

Amino Acid Sequence↗
PubMed1999

A lung metastasis from giant cell tumor of bone at eight years after primary resection.

We report a case of extensive pulmonary metastasis from a histologically benign giant cell tumor. A 34-year-old woman had undergone tumor resection, curettage and artificial bone grafting for giant cell tumor in the left tibia. At eight years after surgery, a chest radiograph revealed an extensive tumor shadow in the right thoracic cavity. Tumor resection with right upper and middle bilobectomy was performed. Its histological features were consistent with those of the primary tumor of the tibia. Distant metastases from a giant cell tumor of bone are rare, with only 50 reported cases. Metastasis has occurred mainly within 3 years after the primary resection. However, in 20% of reported cases, metastasis occurred after 5 years or longer. Long-term follow-up and careful observation for distant metastasis are necessary for this histologically benign disease.

Adult↗