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H Kobayashi

Publications and source records attributed to H Kobayashi.

At least 433 records · Page 24Linked to original sources
PubMed2000

Effect of aging on unscheduled DNA synthesis induction by UV-B irradiation in hairless mouse epidermis.

Age-related induction of unscheduled DNA synthesis (UDS) by ultraviolet B (UV-B) irradiation was investigated in the epidermis of female hairless mice by means of an in vivo--in vitro assay using a liquid scintillation counting method. Skin samples were taken and cultured in a medium containing [3H]thymidine with or without hydroxyurea (HU) for 2 hr. DNA of the epidermis was extracted, and the incorporation of [3H]thymidine into DNA and the DNA content were determined with a liquid scintillation counter and a fluorescence spectrophotometer, respectively. Induction of UDS by UV-B was judged in terms of the value of the UDS index calculated as a percentage of the respective unexposed control value taken as 100% [the UDS index is given by (the ratio of DNA synthesis in the presence of HU to that in its absence) x 100]. DNA synthesis both in the presence and absence of HU decreased with age [12 months old (M) < 8 M < 4 M < 2 M < 1 M)], concomitantly with a small but significant increase of UDS index. The decrease was high in the younger age groups and moderate in the older age groups. UV-B increased the UDS index approximately 14-, 12- and 9-fold at 1 hr after 1,000 J/m2 irradiation in 1 M, 2 M and 12 M mice, respectively, and these increases were partly reversed at 4 hr after irradiation. UV-B also increased the UDS index approximately 25-, 24- and 21-fold at 1 hr after 4,000 J/m2 irradiation for each age group. However, there was no statistically significant age-related difference in the magnitude of the UDS index after irradiation of UV-B. These results show that replicative DNA synthesis decreases with age, whereas DNA repair capacity after UV-B irradiation does not change with age under these conditions.

Aging↗
PubMed2000

Ability to coordinate exertion of force by the dominant hand: comparisons among university students and 65- to 78-year-old men and women.

The purposes of this study were to examine the characteristics of ability to coordinate exertion of force in 60 healthy older people (30 men, 30 women) from the viewpoint of sex differences and to compare their performance with those of 60 healthy university students (30 men, 30 women). The test of ability to coordinate exertion of force was conducted by having the subject fit the exertion value of grip strength to a changing demand value appearing on the display of a personal computer (using a bar chart-description form). The changes in the demand value were tracked. The variable estimating ability to coordinate exertion of force was the total sum of the differences between demand and the produced grip strength induced by time lapses. The ability to coordinate exertion of force in the older subjects was inferior to that of the younger subjects, and large individual differences were observed. Unlike the younger subjects, the means of the ability to coordinate exertion of force of the older subjects significantly decreased between trials. The ability to coordinate exertion of force of the older women was significantly inferior to that of the older men, but the means of the measurements among three trials shows a similar tendency to decrease in both sexes.

Adolescent↗
PubMed2000

Auto-induction and growth stimulatory effect of betacellulin in human pancreatic cancer cells.

Betacellulin (BTC) was identified in mouse pancreatic beta cell tumors as a member of the epidermal growth factor (EGF) family, and was found to bind and activate the EGF receptor. BTC is also expressed in some human malignancies and may have an important role in tumor growth progression. We examined whether BTC and EGF have a growth stimulatory effect on human pancreatic cancer cell lines both in vitro and in vivo. We also investigated the BTC expression and autonomous induction of BTC in pancreatic cancer cells. in vitro, both BTC and EGF had almost the same proliferative effect on Panc-1, MIA PaCa-2 and AsPC-1. in vivo, in a Panc-1 inoculated athymic mice model, BTC-treated tumors grew approximately five times larger than in control. Immunocytochemistry showed that BTC expression occurred in three pancreatic cancer cell lines, with MIA PaCa-2 showing the strongest intensity. Semi-quantitative RT-PCR of MIA Paca-2 showed that mRNA levels of BTC gradually increased after treatment with 1 nM BTC. Immunocytochemistry also demonstrated that the intensity of BTC-like immunoreactivity was increased when treated with 1 nM BTC but was reduced after treatment with 100 nM of AG1478, an EGF receptor tyrosine kinase inhibitor. BTC has thus a significant growth stimulatory effect on pancreatic cancer cells and might function as an autocrine and paracrine growth factor. BTC expression in pancreatic cancer cells is, at least in part, controlled by an auto-induction mechanism.

Animals↗
PubMed2000

Intraoperative pancreatoscopy for pancreatic duct stone debris distal to the common channel in choledochal cyst.

BACKGROUND/PURPOSE: Pancreatic duct stone debris is a recognised problem in patients with choledochal cyst (CC). The authors present the use of intraoperative pancreatoscopy (IP) in diagnosis and treatment of pancreatic duct stone debris distal to the common channel (distal PDSD). METHODS: Sixty-seven patients with CC treated over the past 12 years were reviewed retrospectively. Distal PDSD was detected in 8 of these 67 cases (11.9%) using cholangiography. IP of the common channel or pancreatic duct at the time of surgery for CC was performed using a pediatric cystoscope in 7 of these 8 cases. RESULTS: All 8 patients had a long common channel. All presented with acute pancreatitis. In 7 of these 8 patients, IP was efficient in detecting and for removing distal PDSD by irrigation. In the remaining case associated with annular pancreas, distal PDSD was identified in the proximal pancreatic duct and was removed directly after incision of the pancreatic duct. Postoperative pancreatitis occurred in only 1 case. All patients are well after a mean follow-up period of 7.3 years. CONCLUSION: Distal PDSD should not be ignored. IP allows direct examination of the pancreatic duct system and facilitates complete removal of distal PDSD, which may be the cause of relapsing pancreatitis or pancreatolithiasis after radical surgery for CC.

Acute Disease↗
PubMed2000

[Non-randomized study on the effects of preoperative radiotherapy and daily administration of low-dose cisplatin against those of radiotherapy alone for oral cancer--effects on local control, control of metastases, and overall survival].

Cisplatin is a known radiation modifier. Our previous study suggested that daily administration of low-dose cisplatin enhanced the efficacy of radiotherapy against primary oral squamous carcinoma. In this paper, we follow the patients who participated in the previous study and survey the benefit of combination low-dose cisplatin in improving local control, prevention of metastases, and overall survival. This study included patients with surgically resectable advanced oral tumors. Ten patients underwent preoperative radiotherapy of 30-40 Gy/15-20 days with concomitant daily administration of low-dose cisplatin (5 mg/body or 5 mg/m2). Ten other patients received external radiotherapy alone. All patients then underwent a planned radical tumor resection. No significant difference was see in loco-regional control rates (primary: 86 vs. 88%, neck: 83 vs. 78% at 48 months) or incidence of metastasis (70 vs. 64%) between the two groups. Nor was there a significant difference in the overall survival rate (60 vs. 66%). The results of this study suggest that the concomitant use of daily administration of low-dose cisplatin with preoperative radiation brings no statistically significant benefit in improving local control and survival rate in patients with advanced resectable oral cancer.

Adult↗
PubMed2000

Role of nitric oxide in airway remodelling.

Airway remodelling, which is manifested by thickening of bronchial wall, is an important causative factor of bronchial hyper-responsiveness in asthma. The pathophysiological mechanism of airway remodelling is not clear. In the present study we evaluated the relationship between nitric oxide (NO) generation and airway wall thickening in patients with chronic asthma. As a marker of NO production, the levels of nitrite/nitrate were measured in induced sputum, and bronchial wall thickening was measured by high-resolution computed tomography. Sputum concentrations of nitrite/nitrate were significantly increased in asthmatic patients compared with controls. The ratio of airway wall thickness to lumen diameter was significantly correlated with the sputum concentration of nitrite/nitrate. Although statistical correlation does not prove causation, this finding suggests that NO may play a key role in the pathogenesis of airway remodelling.

Asthma↗
PubMed2000

Effects of insulinlike growth factor binding proteins on insulinlike growth factor-I biodistribution in tumor-bearing nude mice.

UNLABELLED: This study evaluated the biodistribution and tumor targeting ability of radiolabeled insulinlike growth factor (IGF)-I. Because IGF binding proteins (IGFBPs) play a critical role in modulating IGF activity, the binding properties of 125I-labeled IGF-I to IGFBPs were investigated in vitro and in vivo. Because a large amount of the IGF-I was catabolized in vivo, we also studied the catabolism of IGF-I by tumor cells in vitro. METHODS: 125I-labeled-IGF-I was prepared using the chloramine T method. The biodistribution of 125I-labeled-IGF-I in tumor-bearing nude mice was compared between groups injected with 125I-labeled IGF-I alone or coinjected with unlabeled peptide. In vitro and in vivo chromatography studies were performed to evaluate the binding profile to IGFBPs and the degree of catabolites in serum as well as urine. RESULTS: Data indicated that the binding of radiolabeled IGF-I to IGFBPs in vitro was dose dependent. However, there was a difference in complex formation between the serum and the heparinized plasma. In heparinized plasma, the radioactivity shifted from a 30- to 50-kDa complex to a 150-kDa complex and to a free ligand, because the binding of heparin with IGFBPs decreased its affinity for IGF-I. In plasma prepared with acid citrate dextrose a binding pattern identical to that of serum was observed. Moreover, there was a binding difference between mouse and rat. The 125I-labeled IGF-I catabolized very quickly when incubated at 37 degrees C but not at all at 4 degrees C. In tumor-bearing nude mice, the uptake of radioactivity in normal tissues decreased quickly, particularly in the kidneys. In mice coinjected with unlabeled carrier, the radioactivity in most normal tissues was lower and the tumor uptake higher than in the mice without carrier. CONCLUSION: These data confirm that 125I-labeled IGF-I is avidly bound to IGFBPs, both in vitro and in vivo. By partially saturating this binding with unlabeled peptides, a favorable biodistribution was achieved, including faster clearance from normal tissue and higher tumor uptake, which resulted in better tumor-to-nontumor ratios. Nevertheless, the rapid catabolism and release of the radiolabel from tumor tissue result in a suboptimal targeting agent.

Animals↗
PubMed2000

Three-dimensional imaging of tumor angiogenesis.

OBJECTIVE: To three-dimensionally visualize the microvessel environment of tumor angiogenesis by confocal laser scanning microscopy (CLSM). STUDY DESIGN: To reveal underlying mechanisms of tumor angiogenesis, a 7, 12-dimethylbenz(a) anthracene-induced rat cancer model was used. For demonstrating tumor vasculature, fluorescence injection method (FITC-conjugated gelatin solution) was employed. FITC gelatin was injected into the left ventricle of the rat heart. After complete perfusion, the mammary glands were resected, fixed under ice cold conditions and subjected to immunohistochemistry (IHC) for tumor cells. The LSM-410 (Carl Zeiss, Jena, Germany) was employed on thick sections (300-2,000 microns) to elucidate detailed microvessel networks (MVN) and tumor cells. RESULTS: Tumor vasculature on thick sections was clearly detected by CLSM at the maximum focus depth of 2,000 microns. Three-dimensional (3-D), reconstructed images of normal mammary glands showed regular and linear MVN. In DMBA-induced mammary cancer, vascular density of MVN was markedly increased and showed an anastomosing, irregular MVN pattern. Furthermore, focal segmentation and tortuous, branching patterns of microvessels were also seen. CONCLUSION: Application of the fluorescence injection method and IHC using CLSM was very useful for studying the 3-D relationship between tumor angiogenesis and neoplastic epithelial changes. These results suggest that application of this technique is ideal for studying 3-D imaging of tumor angiogenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2000

[Toxicosis of high-dose methotrexate (HD-MTX) for osteosarcoma, cured with treatment by leucovorin (LV) rescue and hemoperfusion--a case report].

A 17-year-old boy suffered from osteosarcoma in his left distal femur. He was treated with 4 courses of HD-MTX preoperatively, then a wide resection and replacement with endprosthesis was performed. After surgery, 4 more courses of HD-MTX were administered. In the last course of HD-MTX, the serum level of MTX had not decreased to a safe level after 48 hours following MTX administration. Liver and renal dysfunction then occurred, so massive leucovorin rescue and hemoperfusion were done. Fortunately, all complications disappeared. The patient is alive and well, and has been disease free for six years since surgery.

Adolescent↗
PubMed2000

Pharmacokinetics of 111In- and 125I-labeled antiTac single-chain Fv recombinant immunotoxin.

UNLABELLED: The use of immunotoxins for cancer therapy is an attractive strategy that exploits the targeting specificity of monoclonal antibodies and their fragments as well as the exquisite toxicity of the toxins. However, few studies of immunotoxins have evaluated their biodistribution in vivo. Previous studies have used 125I for tracing immunotoxin biodistribution in mice. Because the immunotoxin works only when it is internalized and because of known problems with quick dehalogenation after internalization of antibodies, we decided to use 111In, which has greater intracellular retention than iodine. METHODS: To trace the in vivo pharmacokinetics of the immunotoxin in mice, we labeled the antiTac(Fv)-PE38 with 111ln and compared it with 125I-labeled antiTac(Fv)-PE38. We successfully labeled antiTac(Fv)-PE38 with 111In at up to 2.96 GBq/mg. A 3- to 4-fold decrease in cytotoxicity was observed for both radiolabeled preparations. We evaluated the internalization of 111In- and 125I-labeled antiTac(Fv)PE38 into ATAC4 cells (Tac-positive) as well as their biodistribution and pharmacokinetics in vivo in mice. In addition, some mice receiving these reagents were co-infused with 30 mg L-lysine to inhibit renal accumulation. RESULTS: Significantly more 111In- than 125I-labeled antiTac(Fv)-PE38 accumulated in the ATAC4 cells (20% versus 5% of initial surface-bound radioactivity; P < 0.001). In vivo, significantly more 111In- than 125I-labeled antiTac(Fv)-PE38 accumulated in the kidney (119 versus 31 percentage injected dose per gram [%ID/g]; P < 0.001). The tumor accumulation of 111In-labeled antiTac(Fv)-PE38 at 96 h was 13-fold greater than that of 125I-labeled antiTac(Fv)-PE38 (1.4 versus 0.1 %ID/g; P < 0.001). No antiTac(Fv)-PE38 was excreted into the urine in its intact form unless lysine was co-infused. Co-injected lysine reduced the renal accumulation of 111In-labeled antiTac(Fv)-PE38 by 62%. CONCLUSION: We evaluated the biodistribution, pharmacokinetics, and catabolism of 111In-labeled antiTac(Fv)-PE38 and found that it differed from 125I-labeled antiTac(Fv)PE38. These studies suggest that 111In-labeled antiTac(Fv)-PE38 can be used to trace the fate of antiTac(Fv)-PE38 in humans.

Animals↗
PubMed2000

Linkage of autosomal recessive hereditary spastic paraplegia with mental impairment and thin corpus callosum to chromosome 15A13-15.

To date, three loci for autosomal recessive hereditary spastic paraplegia (ARHSP) linked to chromosomes 8p12-q13, 16qter, and 15q13-15 have been characterized. We have clinically characterized 13 Japanese ARHSP families and performed genetic linkage analyses. All 13 families were classified as having the "complicated" form, which manifests with mental impairment and thin corpus callosum. Linkage to the 8p12-q13 and 16qter loci was excluded, although 10 of the 13 families showed marker data consistent with linkage to the 15q13-15 locus. The multipoint LOD score of the 10 families linked to chromosome 15 was above 9.00 in the 3-centimorgan segment flanked by D15S994 and D15S659, with a maximum multipoint LOD score of 9.68 at a position 1.2 centimorgans telomeric from D15S994 to D15S659. We have shown that ARHSP with thin corpus callosum, a subtype of recessive spastic paraplegia, maps to chromosome 15q13-15.

Adolescent↗
PubMed2000

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1998)].

The bacteria isolated from the patients with lower respiratory tract infections were collected by institutions located throughout Japan, since 1981. Ikemoto et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and analyzed some characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In these 18 institutions around the entire Japan, 532 strains of presumably etiological bacteria were isolated mainly from the sputa of 438 patients with lower respiratory tract infections during the period from October in 1998 to September in 1999. MICs of various antibacterial agents and antibiotics were determined against 85 strains of Staphylococcus aureus, 100 strains of Streptococcus pneumoniae, 96 strains of Haemophilus influenzae, 75 strains of Pseudomonas aeruginosa (non-mucoid strains), 6 strains of Pseudomonas aeruginosa (mucoid strains), 38 strains of Moraxella subgenus Branhamella catarrhalis, 26 strains of Klebsiella pneumoniae etc., and the susceptibilities of 517 strains were assessed except for those strains that died during transportation. S. aureus strains for which MICs of oxacillin (MPIPC) were higher than 4 micrograms/ml (methicillin-resistant S. aureus: MRSA) accounted for 60.0%. Vancomycin (VCM) and arbekacin (ABK) showed the most potent activities against MRSA. But one of MRSA showed resistance to ABK with the MIC of 64 micrograms/ml. The sensitive strains of MRSA to VCM have decreased. The frequency of penicillin (PC)-intermediate S. pneumoniae (PISP) + PC-resistant S. pneumoniae (PRSP) have increased in 46.0% for 1998 comparatively from 30.9% of 1997's. But PRSP decreased, and PISP increased into 39.0% of 1998 years from 19.8% of 1997's. Panipenem (PAPM), imipenem (IPM) and faropenem (FRPM) showed the most potent activities against S. pneumoniae with MIC80s of 0.125 microgram/ml or below. Against H. influenzae and M. (B.) catarrhalis, almost all the drugs showed good activities. The sensitive strains of them against ceftazidime (CAZ) decreased in 1997, but those have increased in 1998. Inversely, the susceptibility of them against cefotiam (CTM) had been higher in 1997, but those have been lower in 1998. Tobramycin (TOB) showed the most potent activity against P. aeruginosa (both mucoid and nonmucoid strains). All drugs except ampicillin (ABPC) were active against K. pneumoniae. A quite few of K. pneumoniae showed low susceptibilities. Also, we investigated year to year changes in the characteristics of patients, their respiratory infectious diseases, and the etiology. The examination of age distribution indicated that the proportion of patients with ages over 70 years was 48.6% of all the patients showing a slight increase in every year. About the proportion of diagnosed diseases as follows: Bacterial pneumonia was the most frequent with 40.2%. The ratio of it has increased slightly, and the increased rate was 10% in patients with ages over 70 years compared with the results in 1997. Chronic bronchitis have decreased slightly with 27.6% in 1998. Number of strains isolated from patients before administration of antibiotics were more than those after administration of them in chronic bronchitis, but these were almost same number in bacterial pneumonia. Administration of antibiotics has changed the results of the frequency of isolation of bacterial species. Bacterial isolations before administration of antibiotics were as follows: S. pneumoniae 26.7%, H. influenzae 23.8%, S. aureus 13.3% and M. (B.) catarrhalis 10.8%. The frequencies of S. aureus decreased after antibiotics administration over 15 days, but the frequencies of P. aeruginosa (both mucoid and non-mucoid) was not affected. The frequencies of P. aeruginosa was 45.5% after administration over 15 days. The frequencies of S. pneumoniae decreased upon administration of antibiotics, these were only 4.5% over 15 days. The frequencies of H. (

Anti-Bacterial Agents↗
PubMed2000

[Randomized comparative study of CMF (cyclophosphamide, methotrexate and 5-fluorouracil) and UFT-tamoxifen regimens as adjuvant chemotherapy after surgery for breast cancer: Tochigi Prefectural Study Group for Post-Breast Cancer Adjuvant Chemotherapy].

This prospective randomized study aimed at establishing the optimal postoperative adjuvant chemotherapy regimen for premenopausal n+ breast cancer patients. The treatments were Regimen A, comprising 6 courses of CMF (cyclophosphamide, 100 mg/body on days 1-14; methotrexate, 40 mg/m2 on days 1 and 8; and 5-fluorouracil, 500 mg/m2 on days 1 and 8), and Regimen B, consisting of UFT (300 mg/day) and tamoxifen (30 mg/day) administered orally each day for 2 years. Telephone registration allocated the patients to the treatment groups by the minimization method in relation to the T category, number of n+ lesions and estrogen receptor status. Forty-five patients were registered, and 44 of them were eligible (22 cases each to Regimen A and Regimen B). The principal background factors showed no biases between the groups. The adverse reaction incidence was significantly higher with Regimen A (90.9% vs 22.7%). The 5-year survival rate was 89.8% with Regimen A and 100% with Regimen B, while the 5-year disease-free rates were 64.5% and 76.3%, showing no statistical significance. Regimen B showed a better QOL rating after 6 months of therapy in relation to nausea-vomiting and hair loss, and after 24 months in relation to appetite, sleep, performance status, happiness, anorexia and hair loss.

Adult↗