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Biomedical subjects

H Baba

Publications and source records attributed to H Baba.

At least 55 records · Page 3Linked to original sources
PubMed2000

Novel way of separating polyfluorocarboxylic acids by ion-exclusion chromatography.

Ion-exclusion chromatography has been successfully applied to the separation of a number of polyfluorocarboxylic acids. The separation of various mono- and dibasic polyfluorocarboxylic acids having a different alkyl group was investigated using a polymethacrylate-based weakly acidic cation-exchange resin (TSK gel OApak-A) in the H -form and conductimetric detection. When water was used as the eluent, polyfluorocarboxylic acids could not be resolved. When an aqueous solution of sulfuric acid, benzoic acid, o-phthalic acid, 1,3,5-benzenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, and tartaric acid was used, the separation of polyfluorocarboxylic acids occurred for monobasic ones. While, for fluorine-containing dibasic acids, imperfect separation of peaks occurred. In order to improve their separation, the effect of an addition of organic modifiers such as methanol, 2,2,2-trifluoroethanol and 2H-hexafluoro-2-propanol in the eluent was also investigated.

Carboxylic Acids↗
PubMed2000

High expression of vascular endothelial growth factor is associated with liver metastasis and a poor prognosis for patients with ductal pancreatic adenocarcinoma.

BACKGROUND: Vascular endothelial growth factor (VEGF), a recently identified growth factor with significant angiogenic properties, is a multifunctional angiogenic cytokine that is expressed in many tumors. High VEGF expression has been shown to correlate with the incidence of metastasis and poor prognosis in various cancers. In this study, the authors investigated VEGF expression and microvessel density (MVD) in ductal pancreatic adenocarcinoma and examined the correlations among VEGF expression, clinicopathologic factors, and clinical outcome. The authors especially focused on the correlation between VEGF expression and liver metastasis. METHODS: Paraffin embedded tumor specimens of 142 surgically resected pancreas carcinoma were immunohistochemically stained for VEGF and MVD. The correlations among VEGF expression and MVD, clinicopathologic factors, and clinical outcome were then statistically analyzed. RESULTS: One hundred thirty-two (93%) of 142 ductal pancreatic adenocarcinomas were positive for VEGF protein by immunohistochemistry. A significant correlation was observed between VEGF positivity and MVD (P < 0.0001). Multivariate logistic regression analysis indicated a significant association between high VEGF expression and liver metastasis (P = 0.010) but no other factors, such as age, tumor size, histologic type, lymph node metastasis, venous invasion, neural invasion, peritoneal metastasis, or local recurrence. Patients with tumors that showed moderate or high VEGF expression had significantly shorter survival than patients with low VEGF expression or none at all in their tumors (P < 0.05). CONCLUSIONS: These results indicate that VEGF expression is closely correlated with MVD and seems to be an important predictor for both liver metastasis and poor prognosis in ductal pancreatic adenocarcinoma.

Adult↗
PubMed2000

Mesencephalic neural stem (progenitor) cells develop to dopaminergic neurons more strongly in dopamine-depleted striatum than in intact striatum.

Epidermal growth factor (EGF)/fibroblast growth factor (FGF)-responsive stem (progenitor) cells from embryonic brain have self-renewing and multipotent properties and thus are good candidates for donor cells in neural transplantation. However, the survival and differentiation to mature neurons after grafting of stem cells into adult brain are rather poor. We hypothesize that the differentiation of stem cells to mature neurons, such as dopaminergic (DAergic) neurons, is dependent on environmental cues that control the ontogenic development. We compared the survival and differentiation between mesencephalic (MS) and cortical (CTx) stem (progenitor) cells, following grafting into bilateral striata of hemiparkinsonian model rats. MS and CTx stem cells were prepared from E12 rats and proliferated in serum-free medium with EGF or basic FGF for 2 weeks. One day after being primed to differentiate, the cell suspensions of both origins were grafted into the bilateral striata of adult rats that had unilateral 6-OHDA lesions in the substantia nigra. MS cells differentiated to tyrosine hydroxylase (TH)-positive neurons more strongly in DA-depleted striatum than in intact striatum, and methamphetamine-induced rotation was ameliorated in half of the grafted animals. Rosette-like cell aggregation and dysfunction of the blood-brain barrier (BBB) were less in and around the grafts in DA-depleted striatum, suggesting less proliferation and more differentiation of MS stem cells in DA-depleted striatum. Neither TH-positive neurons nor behavioral amelioration were detected following CTx stem (progenitor) cell transplantation in the striata. Data suggest that the DA-depleted striatum offers a suitable environment for MS stem (progenitor) cells to differentiate into mature DAergic neurons.

Animals↗
PubMed2000

Successfully treated descending necrotizing mediastinitis through mediansternotomy using a pedicled omental flap.

A 21-year-old man with an oropharyngeal abscess admitted to our institution was initially treated with systemic antibiotics but was referred to our department when his condition rapidly deteriorated. His respiratory insufficiency required circulatory support. A computed tomographic scan showed a parapharyngeal abscess descending into the mediastinum with multiple right-side capsulized empyema and pericardial effusion. We conducted emergency surgery through a mediansternotomy using a pedicled omental flap. Postoperative clinical and radiologic assessment showed a normal chest X-ray and primary wound healing without sternal dehiscence. Mediansternotomy using a pedicled omental flap offers excellent exposure for a complete one-stage operation with debridement of all affected tissues of the subauricular region, the mediastinum, and both pleural cavities. We conclude that this method yields good results for patients with acute widespread descending necrotizing mediastinitis.

Adult↗
PubMed2000

Comparison of standard coronary artery bypass grafting and minimary invasive direct coronary artery bypass grafting. Early and mid-term result.

OBJECTIVES: We studied indications and problems involved in minimally invasive coronary artery bypass grafting (MIDCAB). METHODS: We compared patients profiles, graft patency, stenosis severity, morbidity, mortality, long-term survival and freedom from cardiac accidents in 174 patients undergoing elective standard coronary artery bypass grafting (CABG) and 128 undergoing between January 1996 and March 1999. RESULTS: No statistically difference was seen in gender, diabetes mellitus, renal failure, cerebrovascular accident, multi-vessel disease ratios, or left main trunk stenosis between 2 groups. Internal thoracic artery graft patency was 97% (114/118) and the rate of anastomotic stenosis (> 50%) was 9% (10/118) compared to 96% (213/221) in the MIDCAB group. The 3-year survival rate was 91% in the MIDCAB group and 92% in the CABG group and freedom from cardiac accidents, most involving pericutaneus transluminal coronary angioplasty retreatment, was 66% in the MIDCAB group and 88% in the CABG group. CONCLUSION: Although patency and stenosis incidence did not differ between 2 groups, freedom from cardiac accidents was lower in the MIDCAB group.

Aged↗
PubMed2000

Bone grafting in cementless total hip replacement for congenital dysplasia of the hip.

We reviewed 27 cementless primary total hip replacements in patients with osteoarthrosis secondary to congenital dysplasia of the hip. Autogenous bone grafting was used as augmentation. On average the follow-up period was 9 years. Two hips were revised and three acetabular components were considered loose. In hips with loose cups the average graft coverage was significantly greater than in stable hips. The use of a cementless acetabular component is encouraging for reconstruction, although extensive grafting should be avoided. Our study suggests that cementless reconstruction in dysplastic hips yields a satisfactory outcome.

Adult↗
PubMed2000

Spontaneous remission of a solitary intraspinal synovial cyst of the lumbar spine.

We report on a 15-year-old boy in whom a spontaneous remission of a symptomatic synovial cyst, possibly emanating from the L4-5 facet joint, was noted. The medical history suggested that sport-related overactivity and/or minor trauma was the underlying cause. Conservative treatment for several months may be one treatment option if the cyst wall is not calcified and the symptoms and signs related to radiculopathy show a gradual decrease.

Adolescent↗
PubMed2000

A simple technique of using novel thread-holding and knot-pushing forceps for extracorporeal knot-tying.

We designed some novel knot-pushing forceps for extracorporeal knot-tying and describe herein our simple technique of utilizing them. These forceps are modified only by a single 1-mm hole between their jaws, which hold a thread and push the knot toward the ligating tissue. The application of this simple device was handled well by surgeons beginning to perform advanced endoscopic surgery. The simple modification explained in this report seems applicable to most of the forceps currently used.

Endoscopy↗
PubMed2000

Intra-uterine physical growth in schizophrenia: evidence confirming excess of premature birth.

BACKGROUND: Many studies have suggested a possible aetiological role for obstetric complications in the development of schizophrenia. We focused on prenatal physical growth in schizophrenia, a contentious issue in the literature. METHODS: We compared gestational age at birth, birth weight (BW) and birth head circumference (BHC) between 312 schizophrenics and 517 controls, and between 187 schizophrenics and their matched healthy siblings. Information on obstetric histories was obtained from the Maternal and Child Health Handbooks (i.e. contemporaneous records). RESULTS: Gestational age at birth was significantly earlier in the schizophrenics than in the controls (P = 0.017). Pre-term birth (gestational age of 36 weeks or less) was more common in schizophrenics than in controls (8.0% v. 3.4%, P = 0.005, odds ratio 2.5). Low BW (2500 g or less) was more frequent in schizophrenics than in controls (9.6% v. 4.6%, P = 0.005, odds ratio 2.2). The schizophrenics had significantly lighter BW (P = 0.0003) and tended to have smaller BHC (P = 0.081) compared with controls. However, multiple regression analysis showed that there was no significant difference in BW or BHC between the schizophrenics and controls when gestational age and maternal weight were controlled. There was no significant difference in BW or BHC between schizophrenics and their siblings, although the schizophrenics tended to be born at earlier gestational age than their siblings. CONCLUSIONS: Our results suggest that prematurity at birth is associated with a risk of developing schizophrenia in adulthood. When gestational age and maternal body weight were allowed for, there was no evidence that schizophrenics tend to have lower mean BW or smaller BHC.

Adult↗
PubMed2000

In vitro hyperprocessing of Drosophila tRNAs by the catalytic RNA of RNase P the cloverleaf structure of tRNA is not always stable?

We have previously reported that the catalytic RNA subunit of RNase P of Escherichia coli (M1 RNA) cleaves Drosophila initiator methionine tRNA (tRNA(Met)i) within the mature tRNA sequence to produce specific fragments. This cleavage was dependent on the occurrence of an altered conformation of the tRNA substrate. We call this further cleavage hyperprocessing. In the present paper, to search for another tRNA that can be hyperprocessed in vitro, we used total mature tRNAs from Drosophila as substrates for the in vitro M1 RNA reaction. We found that some tRNAs can be hyperprocessed by M1 RNA and that two such tRNAs are an alanine tRNA and a histidine tRNA. Using mutant substrates of these tRNAs, we also show that the hyperprocessing by M1 RNA is dependent on the occurrence of altered conformations of these tRNAs. The altered conformations were very similar to that of tRNA(Met)i. We show here that M1 RNA can be used as a powerful tool to detect the alternative conformation of tRNAs. The relationship between these hyperprocessing reactions and stability of the tRNA structure will also be discussed.

Alanine↗
PubMed2000

Semiquantitative immunoblot analysis of nm23-H1 and -H2 isoforms in adenocarcinomas of the lung: prognostic significance.

Total amounts of nm23 protein and relative levels of H1 and H2 isoforms were studied in 27 fresh-frozen samples of pulmonary adenocarcinoma and adjacent non-neoplastic tissues that were obtained at surgery. Semiquantitative immunoblotting with a monoclonal antibody (Pan-242) against nm23 protein demonstrated both isoforms, recognized as 20.5 kDa for H1 and 18.5 kDa for H2, to be present in all cases. Both H1 and H2 levels in neoplastic tissues were higher than in the corresponding non-neoplastic samples. Expression of H2 was usually greater than of H1. The H2/H1 ratio varied from 1.9 to 14.1 (mean value 5.2) in non-neoplastic tissues and 1.0-5.9 (mean value 2.5) in neoplastic tissues, although this ratio did not correlate with any prognostic factor like tumor size, nodal status or distant metastasis (TNM tumor stage). H1 and H2 levels were significantly lower (mean values 4.3 and 2.4) in well-differentiated than in moderately and poorly differentiated adenocarcinomas (8.3 and 3.0) (P < 0.03 and P < 0.05, respectively). These data indicate that H1 and H2 isoform levels correlate with histological differentiation, but not the metastatic potential or stage of pulmonary adenocarcinoma.

Adenocarcinoma↗
PubMed2000

Serial measurement of polyethylene wear of well-fixed cementless metal-backed acetabular component in total hip arthroplasty: an over 10 year follow-up study.

Serial radiographic measurements of polyethylene wear were performed in 38 hips (33 patients) with primary cementless total hip arthroplasty (THA). The average follow-up period was 131.8 months. All prostheses were assessed as radiographically stable at the latest follow-up. A two-dimensional method was used to calculate the relative migration of the femoral head center to the cup center. The average total linear wear and wear rate were 1.22 mm and 0.11 mm/year, respectively. The degree of wear in the first 2 postoperative years accounted for nearly 40% of the total wear at the end of the study (average follow up: 131.8 +/- 10.0 months, +/-SD). The migration of the femoral head at an average period of 3. 4 months after operation accounted for 56% of the amount of wear in the first 2 years. Wear rate decreased gradually with time and stabilized after the fourth year. However, in 2 patients, a progressive increase in the wear rate was associated with severe osteolysis and failure of THA. Both creep and wear contributed to the femoral penetration into the polyethylene liner. The influence of creep cannot be ruled out, especially in the early period after operation. Polyethylene wear is a multifactorial process, and the study of individual wear patterns might be useful in identifying patients who are at risk of late failure of THA.

Acetabulum↗
PubMed2000

Phase II study of S-1, a novel oral fluorophyrimidine derivative, in patients with metastatic colorectal carcinoma. S-1 Cooperative Colorectal Carcinoma Study Group.

This study set out to evaluate, in patients with metastatic colorectal carcinoma, the efficacy and toxicity of S-1, which contains tegafur, 5-chloro-2,4-dihydroxypyridine (CDHP) and potassium oxonate, based on a biochemical modulation of 5-fluorouracil (5-FU) targeted at inhibition of dihydropyrimidine dehydrogenase (DPD). Sixty-three patients with measurable metastatic colorectal carcinoma were enrolled into the study. None of the patients had received prior chemotherapy except for adjuvant setting. S-1 was administered orally twice daily at a standard dose of 80 mg m(-2) day(-1) for 28 days followed by a 14-day rest. This agent is continued until disease progression, unaccepted toxicity, or patient refusal. Twenty-two (35%) of the 62 eligible patients achieved PR with a 95% confidence interval of 25-48%. Five of the 10 patients with a history of adjuvant chemotherapy achieved partial remission. The median survival time was 12 months. Major adverse reactions included myelosuppressive and gastrointestinal toxicities, though their incidence of grade 3 or 4 being 13% in neutropenia and less than 10% in the others. None of the 53 patients treated as outpatients required hospitalization due to adverse reactions: These results suggest that S-1 achieves similar responses to those of infusional 5-FU plus leucovorin and shows the potential of another biochemical modulation with easily manageable toxicity.

Administration, Oral↗
PubMed2000

Changes in E-cadherin associated with cytoplasmic molecules in well and poorly differentiated endometrial cancer.

E-cadherin function is thought to be impaired in epithelial cancer. To investigate the alterations in E-cadherin associated with cytoplasmic molecules including alpha-catenin, beta-catenin, gamma-catenin, p120CAS, and IQGAP1 in various endometrial cancers with different degree of differentiation, we examined the localization and expression of E-cadherin and cytoplasmic molecules in 30 cases of both well and poorly differentiated endometrioid adenocarcinomas, using immunofluorescence and immunoblotting techniques. E-cadherin and cytoplasmic molecules demonstrated linear staining at the cell boundaries in normal endometrium. In all 20 cases with well differentiated adenocarcinomas, alpha-catenin and IQGAP1 disappeared from the cell adhesive sites, but other cytoplasmic molecules were co-localized with E-cadherin along the cell boundaries. In all 10 cases with poorly differentiated adenocarcinomas, E-cadherin and cytoplasmic molecules accumulated as large aggregates along cell adhesive sites, and the localization of IQGAP1 differed from those of other cytoplasmic molecules. The expression of these molecules in all 20 cases with well differentiated adenocarcinomas decreased or was lost in Triton-insoluble fraction, in comparison with the findings for all cases with normal endometrium or poorly differentiated adenocarcinomas. These results suggested that each alteration in E-cadherin associated with cytoplasmic molecules may play a different role in E-cadherin dysfunction between well and poorly differentiated adenocarcinomas.

Adenocarcinoma↗
PubMed2000

The striatum is the most vulnerable region in the brain to mitochondrial energy compromise: a hypothesis to explain its specific vulnerability.

The striatum, together with the hippocampus, is one of the most vulnerable regions in the brain. Recently, genetic abnormalities or mutations have been linked to various neurodegenerative diseases, that is, Huntington's disease, Alzheimer's disease, amyotrophic lateral sclerosis (ALS), etc., but the processes from genetic abnormality to the final phenotypic expression are not well understood. Disturbances in energy metabolism especially in mitochondrial energy compromise could facilitate genetic abnormalities and enhance neuronal cell death. Here, we report that the striatum is the most vulnerable brain region to systemic intoxication with 3-nitropropionic acid (3-NPA), an inhibitor of succinate dehydrogenase inducing energy compromise. We hypothesize that the striatum-specific lesion by 3-NPA is due to cummulative insults characteristic to the striatum including glutamatergic excitotoxicity, dopaminergic toxicity, vulnerability of the lateral striatal artery and high activity in the glutamate-transporter. The former two are extravascular in origin while the latter two are intra-/perivascular. We also discuss the possibility that a high turnover rate in metabolism of nitric oxide (NO) might underlie the vulnerability of the lateral striatal artery. We posit that systemic intoxication with 3-NPA offers a good animal model to investigate the pathophysiology of neuronal/glial cell death, neurodegenerative disease, dysfunction of the blood-brain barrier (BBB), neuroimmune disorders, and stroke.

Animals↗
PubMed2000

The genetic structure of the Raleigh natural population of Drosophila melanogaster revisited.

The Raleigh natural population of Drosophila melanogaster was reanalyzed with special attention to possible dysgenic effects during the extraction of chromosomes. About 600 second chromosomes were extracted from the Raleigh natural population, half in the cytoplasm of wild-caught females (native genetic background) and half in the cytoplasm of the laboratory line, C160(In(2LR)SM1, Cy/In(2LR)bw(V1)) (foreign genetic background). We could not find significant differences between the two extraction schemes in the frequency of lethal second chromosomes (Q = 0.252 for the lines with the negative genetic background vs. 0.231 for the lines with the foreign genetic background) or in the homozygous detrimental (D) and lethal (L) loads (D = 0.210 vs. 0.251; L = 0.287 vs. 0.264). The effective size of the population was estimated to be approximately 19,000, based on the allelism rate of lethal-bearing chromosomes. The homozygous load markedly decreased in the 15 years since a previous study of the same population.

Animals↗