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Biomedical subjects

A Kobayashi

Publications and source records attributed to A Kobayashi.

At least 91 records · Page 5Linked to original sources
PubMed2001

Effects of posterior cruciate ligament resection on the tibiofemoral joint gap.

The effect of posterior cruciate ligament resection on the tibiofemoral joint gap was analyzed in 30 patients with varus osteoarthritis of thee knee who underwent total knee replacement. The medial soft tissue was released and the bone cut was made without preserving the bone segment of the tibia to which the posterior cruciate ligament was attached. Then the medial and lateral joint gaps in full extension and 90 degrees flexion were measured before and after the posterior cruciate ligament was resected using a tensioning device. After the resection, the flexion gap significantly increased in the medial and the lateral sides (4.8 +/- 0.4 and 4.5 +/- 0.4 mm, respectively, mean +/- standard error) compared with those seen in the extension gap (0.9 +/- 0.2 and 0.8 +/- 0.2 mm). There was no significant difference between the changes in the medial and lateral gaps. The mean value of the flexion gap was 2 mm smaller than the extension gap before the resection and 1.7 mm larger after the sacrifice. Overall, posterior cruciate ligament resection resulted in an increase in the flexion gap and made space for approximately 3-mm thicker polyethylene. The flexion gap can be controlled selectively with posterior cruciate ligament release.

Aged↗
PubMed2001

A study of factors influencing prognosis after resection of hepatic metastases from colorectal and gastric carcinoma.

OBJECTIVE: The aim of this study is to determine the absolute contraindication for hepatic resection for colorectal metastases and investigate the value of hepatectomy for gastric metastases by comparing it with the results of colorectal metastases performed with the same criteria. METHODS: A retrospective cohort study was conducted in patients undergoing hepatic resection for metastatic colorectal (n = 64) and gastric (n = 17) carcinomas. Common predictive factors for both metastases were analyzed by the stratified Cox proportional hazard model. In this model, the different baseline hazard was set for each disease, whereas the risk of each covariate was assumed to be equal in both gastric and colorectal metastases. RESULTS: Overall 1-, 2-, and 5-yr survival rates after hepatectomy for colorectal and gastric metastases were 90%, 73%, 42%, and 47%, 22%, 0%, respectively. Factors controlling prognosis were as follows: age > or = 60, extrahepatic metastases, serosal invasion, grade of lymph node metastases, tumor cell differentiation of the primary lesion(s), carcinoembryonic antigen level, tumor-exposed surgical margin, and blood transfusion. In particular, presence of extrahepatic metastases showed the markedly high-risk ratio among these eight variables. CONCLUSIONS: Hepatectomy, if possible, is indicated in patients with hepatic metastases from colorectal carcinoma if there are no extrahepatic metastases and if the primary disease is controlled. It is indicated only in carefully selected patients with metastases from gastric carcinoma.

Adult↗
PubMed2001

Mac-1 (CD11b/CD18) and intercellular adhesion molecule-1 in ischemia-reperfusion injury of rat liver.

The chronological expression (over 24 h) of two adhesion molecules [intercellular adhesion molecule-1 (ICAM-1) and CD11b/CD18 (Mac-1)] and the extent of liver damage, including injury to sinusoidal endothelial cells (SECs) and hepatocyte apoptosis, were investigated under two conditions of rat liver ischemia-reperfusion (I/R) injury: reversible (30 min) and fatal I/R (60 min). The chronological profiles of upregulation of ICAM-1 on hepatocytes and Mac-1 showed changes in parallel with the other liver damage parameters, and the extent of upregulation and various parameters of liver injury were more advanced in the 60-min I/R group. Paradoxically, the degree of ICAM-1 upregulation of SECs decreased significantly in the 60-min I/R group vs. the 30-min I/R group. Repression of hepatocyte apoptosis by administration of the caspase inhibitor ZVAD-fmk resulted in attenuation of neutrophil infiltration and liver injury. These findings indicate that 1) neutrophil infiltration is involved in the development of liver I/R injury; 2) interaction between ICAM-1 on SECs and Mac-1 on neutrophils is not an essential step for neutrophil transmigration through the endothelial layer because SECs, specifically, were impaired in the early stages of liver I/R injury; 3) the role of ICAM-1 and Mac-1 is to adhere neutrophils firmly to hepatocytes and activate neutrophils; and 4) excessive parenchymal apoptosis may be the signal for the neutrophil-induced inflammatory and necrotic reaction.

Amino Acid Chloromethyl Ketones↗
PubMed2001

Fas/FasL-dependent apoptosis of alveolar cells after lipopolysaccharide-induced lung injury in mice.

To determine the possible contribution of apoptosis in the pathogenesis of acute lung injury (ALI), we investigated Fas antigen (Fas), Fas ligand (FasL), perforin, granzyme A, and granzyme B expressions in a murine model of ALI after intratracheal instillation of Escherichia coli lipopolysaccharide (LPS: 0.3-30 microg) into the left lung. Lung injury, examined by water-to-dry weight ratio and albumin leakage, demonstrated maximal epithelial injury 1 d after 30 microg LPS instillation. Expressions of the proapoptosis molecules' mRNA were dose-dependently up-regulated, with maximal expression in the early phase in the instilled lung and most apparent 1 d after LPS instillation. Negligible mRNA expression of proapoptosis molecules was observed in noninstilled lungs. The terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling (TUNEL) demonstrated positive signals in neutrophils and macrophages as well as in alveolar wall cells of the instilled lung 1 d after LPS instillation. Immunohistochemistry demonstrated that Fas was up-regulated in alveolar and inflammatory cells and FasL-positive inflammatory cells migrated into the air spaces in the LPS-instilled lung. Intratracheal administration of P2 antibody, which is an anti-Fas blocking antibody, attenuated the lung injury after 30 microg LPS instillation without attenuating mRNA expressions of proapoptosis molecules and neutrophil accumulation in the lung. In contrast, concanamycin A, which inhibits the function of perforin, did not alter the outcome after LPS instillation. These results indicate that the Fas/FasL system could be important in the pathogenesis of LPS-induced ALI, and proper regulation of the FasL/Fas system might be important for potential treatment of ARDS.

Animals↗
PubMed2001

Large-scale cDNA analysis of the maternal genetic information in the egg of Halocynthia roretzi for a gene expression catalog of ascidian development.

The ascidian egg is a well-known mosaic egg. In order to investigate the molecular nature of the maternal genetic information stored in the egg, we have prepared cDNAs from the mRNAs in the fertilized eggs of the ascidian, Halocynthia roretzi. The cDNAs of the ascidian embryo were sequenced, and the localization of individual mRNA was examined in staged embryos by whole-mount in situ hybridization. The data obtained were stored in the database MAGEST (http://www.genome.ad.jp/magest) and further analyzed. A total of 4240 cDNA clones were found to represent 2221 gene transcripts, including at least 934 different protein-coding sequences. The mRNA population of the egg consisted of a low prevalence, high complexity sequence set. The majority of the clones were of the rare sequence class, and of these, 42% of the clones showed significant matches with known peptides, mainly consisting of proteins with housekeeping functions such as metabolism and cell division. In addition, we found cDNAs encoding components involved in different signal transduction pathways and cDNAs encoding nucleotide-binding proteins. Large-scale analyses of the distribution of the RNA corresponding to each cDNA in the eight-cell, 110-cell and early tailbud embryos were simultaneously carried out. These analyses revealed that a small fraction of the maternal RNAs were localized in the eight-cell embryo, and that 7.9% of the clones were exclusively maternal, while 40.6% of the maternal clones showed expression in the later stages. This study provides global insights about the genes expressed during early development.

Animals↗
PubMed2001

The inhibitory effect of an extract of Sanguisorba officinalis L. on ultraviolet B-induced pigmentation via the suppression of endothelin-converting enzyme-1alpha.

Endothelin-1 (ET-1) has been reported to be expressed in human epidermis at both the gene and protein levels. ET-1 plays a pivotal role in ultraviolet B (UVB)-induced pigmentation due to its accentuated secretion after UVB irradiation and its function as a mitogen and as a melanogen for human melanocytes. We have recently found that endothelin-converting enzyme (ECE)-1alpha plays a constitutive role in the secretion of ET-1 by human keratinocytes and that an extract of Sanguisorba officinalis L. inhibits ECE activity in human endothelial cells, which predominantly express ECE-1alpha. In this report, to clarify the potential use of this botanical extract as a whitening agent, we examined whether this extract inhibits UVB-induced pigmentation in vivo. When this extract was applied to human keratinocytes after UVB irradiation, secretion of ET-1 by those cells was reduced, and this was accompanied by a concomitant increase in the secretion of inactive precursor Big endothelin-1. When hairless mice were exposed to UVB light and were treated with the extract, it suppressed the induction of ET-1 in the UVB-irradiated epidermis. In the course of UVB-induced pigmentation of brownish guinea pig skin, this extract significantly diminished pigmentation in UVB-exposed areas. These findings indicate that ECE-1alpha in keratinocytes plays a pivotal role in the induction of pigmentation following UVB irradiation and that an extract of S. officinalis, which inhibits ET-1 production in human keratinocytes, is a good ingredient for a whitening agent.

Animals↗
PubMed2001

Characterization of a thermostable family 10 endo-xylanase (XynB) from Thermotoga maritima that cleaves p-nitrophenyl-beta-D-xyloside.

Thermotoga maritima MSB8 possesses two xylanase genes, xynA and xynB. The xynB gene was isolated from the genomic DNA of T. maritima, cloned, and expressed in Escherichia coli. XynB was purified to homogeneity by heat treatment, affinity chromatography and ion-exchange column chromatography. The purified enzyme produced a single band upon SDS-PAGE corresponding to a molecular mass of 42 kDa. At 70 degrees C, the enzyme was stable between pH 5.0 and pH 11.4, and it was stable at temperatures of up to 100 degrees C from pH 7.0 to pH 8.5. At 50 degrees C, XynB displayed an optimum pH of 6.14 and at this pH the temperature for optimal enzyme activity was 90 degrees C. XynB exhibited broad substrate specificity and was highly active towards p-nitrophenyl-beta-D-xylobioside with K(m) and k(cat) values of 0.0077 mM and 5.5 s(-1), respectively, at 30 degrees C. It was also active towards p-nitrophenyl-beta-D-xyloside. The initial product of the cleavage of p-nitrophenyl-beta-D-xyloside was xylobiose, indicating that the major reaction in the cleavage was transglycosylation, not hydrolysis.

Journal Article↗
PubMed2001

Adsorption properties and activities of lipase on a gold substrate modified by self-assembled monolayers.

The adsorption properties, amount and specific activity of lipase D from Rhizopus delemar were investigated by employing a gold substrate modified with seven kinds of thiol monolayer. Quartz crystal microbalance measurements revealed that the amount of the enzyme adsorbed to the hydrophobic monolayers (e.g. benzenethiol) was much higher than that to the hydrophilic monolayers (e.g. 3-mercaptopropanoic acid). In contrast, lipase D adsorbed to the hydrophilic, 2-amino-1-ethanethiol monolayer showed the highest specific activity, the value being 300-fold higher than for the same enzyme dissolved in an aqueous medium.

Adsorption↗
PubMed2001

Isolation and identification of trans-2- and trans-3-hydroxy-1,8-cineole glucosides from Alpinia galanga.

Three hydroxy-1,8-cineole glucopyranosides, (1R, 2R, 4S)- and (1S, 2S, 4R)-trans-2-hydroxy-1,8-cineole beta-D-glucopyranosides, and (1R, 3S, 4S)-trans-3-hydroxy-1,8-cineole beta-D-glucopyranoside, which are possible precursors of acetoxy-1,8-cineoles as unique aroma components, were isolated from the rhizomes of greater galangal (Alpinia galanga W.). Their structures were analyzed by FAB-MS and NMR spectrometry, and the absolute configulation of each aglycone was determined by using a GC-MS analysis with a capillary column coated with a chiral stationary phase. The composition of the diastereomers of (1R, 2R, 4S)- and (1S, 2S, 4R)-trans-2-hydroxy-1,8-cineole beta-D-glucopyranosides in the rhizomes was determined as 3:7 by a GC-MS analysis after preparing the trifluoroacetate derivatives of the glucosides.

Carbohydrate Sequence↗
PubMed2001

Identification of hepatic venous territories in liver resection by using color Doppler ultrasonography: report of two cases.

OBJECTIVE: Resection of the hepatic vein because of the proximity of tumors may result in increased congestion in the noncancerous parenchyma, which in turn may lead to functional hepatic volume loss and postoperative hepatic failure, especially in a case of low hepatic reserve. However, to our knowledge, no technique for estimating the extent of dependent hepatic venous territories before hepatic resection has been established. We examined the possibility of using color Doppler ultrasonography for this purpose. METHODS: A color Doppler system and a linear array transducer equipped with multiple Doppler frequencies ranging from 7 to 13 MHz were used intraoperatively. Two patients with hepatocellular carcinomas were examined. By tracking entire branches of the targeted vessel, from the trunk to the terminal branches extending to the liver surface, it was possible for the boundaries of the dependent areas to be projected and marked on the liver surface with either ink or electrocautery. RESULTS: In both cases, this method was effective for either minimizing the congestive area or preserving the hepatic mass that was being drained via aberrant routes. CONCLUSIONS: Identification of hepatic venous territories by means of color Doppler ultrasonography may provide new information about intrahepatic blood circulation and may increase the safety and curability of hepatic resection.

Aged↗
PubMed2001

[Experience of four cases of postoperative pulmonary embolism requiring surgical treatment].

Four patients underwent a pulmonary embolectomy using cardiopulmonary bypass for acute pulmonary embolism which had occurred after various operations. In two cases, dehydration due to either diabetes insipidus or ileus had existed. In two cases, pulmonary embolism suddenly occurred in our hospital. In the remainder, the disease occurred in the previous hospitals and its diagnosis was established on the 6th and 7th postoperative days, respectively. In massive pulmonary embolism, echocardiography and/or enhanced chest CT are useful for prompt and noninvasive diagnosis. Thrombolytic therapy was performed in only one case before surgical embolectomy, which was not effective. Three patients were discharged without any postoperative complications, but one requiring preoperative external cardiac massage died of multiple organ failure 9 days after operation. Acute pulmonary embolism is one of the fatal postoperative complications. Recognition of this entity, and prompt diagnosis and treatment are essential for managing the fatal disease. Even in the early postoperative period, embolectomy using cardiopulmonary bypass is a safe and effective treatment.

Acute Disease↗
PubMed2001

[Indication and outcome of extended right hemihepatectomy combined with pancreatoduodenectomy for bile duct carcinoma].

During the past 10 years, we have performed extended right hemihepatectomy combined with pancreatoduodenectomy (rtHPD) in eight patients with bile duct carcinoma. We compared the results in these patients with those in 43 bile duct carcinoma patients who underwent extrahepatic bile duct resection with more extensive hepatectomy than hemihepatectomy. Our indication for rtHPD is bile duct carcinoma of the diffuse type involving the intrapancreatic bile duct. For patients with obstructive jaundice, biliary drainage was performed preferentially in the part of the liver to be preserved. Portal vein embolization was performed before extended right hemihepatectomy or left trisectorectomy. Complete external drainage of pancreatic juice followed by second-stage pancreatojejunostomy was performed in five rtHPD patients. There were no hospital deaths or hepatic failures. There were four 5-year survivors after rtHPD. There was no significant difference between the cumulative 5-year survival rates after rtHPD (71%) and non-HPD (42%). Patients with bile duct carcinoma whose prognosis can be improved only by rtHPD exist and should be treated by rtHPD. However, considering the reported high mortality rate after this procedure, rtHPD should not be performed in an institution where its safety cannot be guaranteed.

Aged↗
PubMed2001

Characteristics of dorsal lingual papillae of the Bactrian camel (Camelus bactrianus).

The morphology of dorsal lingual papillae of the Bactrian camel (Camelus bactrianus) was studied by using light and scanning electron microscopy. Filiform and lenticular papillae were considered as mechanical papillae but fungiform and vallate papillae were considered as gustatory papillae. Filiform papillae were distributed mostly in the anterior two-thirds region of the tongue. Each filiform papilla consisted of one primary papilla and a few smaller secondary papillae. Lenticular papillae were distributed on the torus linguae. The larger papillae were arranged in two parallel lines medially whereas the smaller papillae were laterally located. Most of the fungiform papillae were found on the lateral margins of the anterior two-thirds of the tongue. These papillae were small and round. Intra-epithelial taste buds were located on the dorsal surface of each papilla. The vallate papillae were arranged in two rows on each rim of the torus linguae. Each round- and flat-shaped vallate papilla was surrounded by a prominent gustatory groove and an annular pad. A few taste buds were observed in the lateral epithelium of the papillae. The keratinization of the covering stratified squamous epithelium of the mechanical lingual papillae was relatively thicker than those of the gustatory papillae. The lingual papillae of the Bactrian camel exhibited some different characteristics from other domestic ruminants. These morphological characteristics of the tongue of the Bactrian camel might have evolved to assist the camel in prehension and manipulating of the inorganic stiff plants that grow in its environment and therefore might relate to the feed and feeding habits of the animal.

Animals↗
PubMed2001

[Two elderly patients with advanced gastric cancer responding to chronomodulation chemotherapy with tegafur + cisplatin + isovorin followed by oral administration of S-1].

Recently, as society ages there have become more elderly gastric cancer patients with/without several complications(cerebrovascular diseases, cardiac diseases, atherosclerosis, DM, etc.), that were non-resected and require highly effective chemotherapy and good QOL. We report two elderly gastric cancer patients responding to chronomodulation chemotherapy (tegafur + cisplatin + Isovorin) based on circadian rhythms plus a new antitumor drug, S-1. The treatment protocol was tegafur 800 mg/body, days 1-7 (continuing 16 h, intravenously with 500 mg/body from 16 to 0 h, 300 mg/body from 0-8 h, for non-uniform administration), cisplatin 10 mg/body, days 1-5, (16 h), Isovorin 25 mg/body, days 1-5, (16 h, oneshot infusion, for 4 courses followed by a week rest. Next was S-1 120 mg/body x 2 times orally for 28 days, followed by 2 weeks rest, the administered for another 28 days. The first patient was 74 years of age, with advanced type 3 plus early type IIc gastric cancers with liver metastasis (H1). After chemotherapy the liver metastasis disappeared, there was a 70% reduction in the advanced cancer and the early cancer disappeared. The second patient was 84 years of age, with advanced type 3 gastric cancer invading the esophagus. After chemotherapy, the primary lesion was reduced 80% and the esophageal invasion mass shrunk. The only adverse effect was grade 2 pancytopenia. In conclusion this regimen resulted in good intrachemotherapeutic QOL and highly effective performance in elderly advanced gastric cancer patient.

Adenocarcinoma↗
PubMed2001

Inhibitory effect of low density lipoprotein on the inflammation-inducing activity of calcium pyrophosphate dihydrate crystals.

OBJECTIVE: It has been proposed that low density lipoprotein (LDL) plays a role in the self-limiting nature of pseudogout inflammation. We investigated changes of LDL concentration in rat air pouch fluid during periods of acute and subsiding inflammation to evaluate whether LDL contributes to inhibiting inflammation of pseudogout. We examined whether LDL binds to calcium pyrophosphate dihydrate (CPPD) crystals as a possible mechanism for reduction of inflammation. METHODS: In this in vivo study, 5 mg suspensions of CPPD crystals and saline were injected into the rat air pouch. Fluid samples were taken from rat air pouch at 0, 3, 6, 12, 24, and 48 h after injection. White blood cells in the samples were counted; the remaining fluid was centrifuged and concentrations of beta-glucuronidase and PGE2 in the supernatant were measured as inflammatory markers. LDL in the supernatant was immunochemically identified by Western blotting, then pellets containing crystals were examined by the same technique. RESULTS: LDL was identified in the air pouch 3 h after CPPD crystal injection, and its concentration increased and reached a peak level after 24 h. Inflammatory markers reached maximal level from 6 to 12 h, then decreased after 24 h. In the pellets containing crystals, LDL could not be identified in every specimen. CONCLUSION: LDL in the rat air pouch increased during the inflammatory course induced by CPPD crystal and the inflammation subsided as the LDL increased. Since some reports indicate LDL was related to reduction of crystal induced inflammation such as gout or pseudogout, we concluded that LDL could contribute to the resolution of acute pseudogout arthritis in vivo with or without binding to CPPD crystals.

Animals↗
PubMed2000

In vitro selection of hematoporphyrin binding DNA aptamers.

DNA aptamers that bind to hematoporphyrin IX (HPIX) were isolated using an in vitro selection technique. Most aptamers obtained after the 7th and 10th rounds contained guanine-rich sequences. Binding assay using fluorescence polarization technique and structural analysis by CD spectra revealed that the parallel guanine-quartet structure of the aptamer participates in the recognition of HPIX.

Base Sequence↗