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Biomedical subjects

Y Ogata

Publications and source records attributed to Y Ogata.

At least 55 records · Page 3Linked to original sources

[mRNA expression of chemokines in rat kidneys with ureteral obstruction].

BACKGROUND: It has been demonstrated that leukocyte infiltration, mainly of macrophages and lymphocytes, into obstructed kidneys (OBK) of rats during unilateral ureteral obstruction (UUO). Chemokines (C-C subfamily) may be involved in this mechanisms. Thus, we accessed the gene expression of chemokines in renal cortex of rats with UUO. MATERIALS AND METHODS: Female SD rats were sacrificed at various time points after UUO. mRNA expression of MCP-1, RANTES and MIP-1 alpha was determined by semi-quantitative RT-PCR. RESULTS: Control kidneys (CNK) showed a weak mRNA expression of MCP-1, RANTES and MIP-1 alpha. OBKs showed an increase in MCP-1 at 2 hours of UUO and a significant increase at 4 hours of UUO as compared with CNKs or contralateral unobstructed kidneys (CLK). The mRNA levels of RANTES and MIP-1 alpha were not increased until 72 hours of UUO in CLKs or OBKs. There were slight, but significant, differences of RANTES and MIP-1 alpha expression between OBKs and CNKs at 120 hours of UUO. CONCLUSIONS: We suggest that the early increase in MCP-1 contributes to the leukocyte infiltration and that RANTES and MIP-1 alpha plays a partial role in a late increases.

Animals↗

[Difficulty in using RP, PL, and EW factors in the Japanese classification of pancreatic carcinoma].

The classification of pancreatic carcinoma by the Japan Pancreas Society reflects the prognosis of each stage better than does the TMN classification. On the other hand, there are too many factors to examine in the Japanese system, some of which are difficult to use and have low accuracy in pre- and/or intraoperative diagnosis (RP and PL), and their analysis requires various specimen handling procedures (EW). We propose that: 1) a simple, easy decision flow chart be established for ew and 2) EW/ew be designated as (-) or (+) and for EW/ew (+) cases other factors (ly, v, pl, and direct tumor invasion) be added (for example, ew (+)-pl).

Humans↗

[Subjective burdens of families caring for "frail elderly" in their homes].

The purpose of the study is to measure the subjective burdens of families caring for "frail elderly" in their homes and to clarify the relationships between caregivers' subjective burdens and the health conditions of the "frail elderly", the family's conditions, the use of social services and availability of social supports. The subjects consisted of caregivers of the elderly who also were using nursing services from K Home Visit Nursing Care Station (K-Station). We mailed subjective burden questionnaires to 98 families among users of K-Station from December of 1994 to March of 1995. We used the 12 items developed by Nakatani as a scale to measure subjective burdens. Each item was stratified into 4 grade levels from "agree" to "disagree". We asked nurses at K-Station about "frail elderly" ADL conditions in detail, the extent of medical dependency and the will of families to care for the elderly. A total of 76 questionnaires were returned, of which 73 could be analyzed. The greater part of "frail elderly" were female (n = 42). The average age of the "frail elderly" was 81.1(+/- 7.6) years old. All caregivers were members of the family of the "frail elderly" and most of them were women (n = 63). From the result of principal analysis, 2 principles were extracted from the 12 items used to measure subjective burden of caregivers. We analyzed the first principle as "subjective burden of caregivers". From the result of multiple regression analysis (Stepwise method), "subjective burden of caregivers" was characterized by the caregivers' conditions only (caregivers' health status, the will to care for the elderly and anxiety of providing night care). This result suggested that support for the caregivers of the "frail elderly" was important to sustain in-home care.

Aged↗

[A patient with gastric cancer with para-aortic lymph node metastases surviving for 9 years after effective preoperative chemotherapy and radical operation].

A 63-year-old male patient with type 3 advanced gastric cancer was referred to our hospital. Preoperative examination by CT-scan revealed swollen para-aortic lymph nodes and cancer invasion to the pancreas. The patient was treated pre-operatively with intravenous 5-FU, 500 mg/body/day, continuous infusion for 1 week. Immediately after the chemotherapy, the patient underwent total gastrectomy, splenctomy, left-adrenectomy and resection of the body and tail of the pancreas, along with para-aortic lymph node dissection. Microscopic examination revealed that the tumor was a moderately differentiated tubular adenocarcinoma, which displayed invasion to the pancreas with lymph node metastasis up to the level 3 lymph node. Histologically, the effect of preoperative chemotherapy showed a grade 2 effect on the main tumor, but a grade 3 chemotherapeutic effect was observed at the para-aortic lymph nodes. The patient has subsequently remained disease free for 9 years. In this case, it is considered that the preoperative chemotherapy by 5-FU and potentially curative radical operation yielded a good outcome.

Adenocarcinoma↗

[Effects of nilvadipine on retinal microcirculation and systemic circulation].

PURPOSE: The effects of nilvadipine on retinal blood flow and systemic circulation were studied by the hydrogen clearance method. MATERIALS AND METHODS: The subjects were 10 male beagles. Under general anesthesia, nilvadipine (32 micrograms/ml/kg), dissolved in polyethylene glycols was injected into the stomach of 5 beagles, and only polyethylene glycols was injected into the stomach of the other 5 beagles as controls. Retinal tissue blood flow, heart rate, arterial blood pressure, pulmonary arterial pressure, central vein pressure, cardiac output, and systemic vessel resistance were measured over time and compared between the two groups. RESULTS: Retinal tissue blood flow showed significant increase only in the Nilvadipine group (max 29.2%). No marked changes were observed in the systemic circulation in either group. The time to maximum blood concentration of Nilvadipine was 120 min, and the maximum blood concentration was 1.27 ng/ml. CONCLUSION: Nilvadipine may directly and selectively increase retinal tissue blood flow, while having only minimal effect on systemic circulation including arterial blood pressure.

Animals↗

[Regional assessment of treatment in lung cancer using lung perfusion and ventilation images].

In 30 patients with lung cancer undergoing non-surgical treatment, we performed perfusion lung imaging using 99mTc-MAA and inhalation lung studies using Technegas before and after treatment and evaluated regional perfusion and ventilation status in the lung regions where bronchogenic carcinoma was located. Regional ventilation status was preserved rather than perfusion counterpart (V > P) in 18 patients (18/30 = 60.0%) before treatment, while the former was better than the latter in 27 patients (27/30 = 90.0%) after treatment, indicating that regional ventilation status improved more significantly than regional perfusion counterpart after treatment (p = 0.005). We also classified the therapeutic effect for regional perfusion and ventilation status as improved, unchanged, or worsened, respectively; improvement in regional perfusion status was observed in 17 patients (56.7%) and that in regional ventilation status in 24 patients (80.0%). There was a statistically significant correlation between improved regional perfusion and ventilation status (p = 0.0018) when therapeutic effect was recognized. The patients who showed improvement in regional perfusion status after treatment always showed improved regional ventilation status, but 7 patients showed either unchanged or worsened regional perfusion status after treatment, although regional ventilation status was improved. In conclusion the pulmonary vascular beds seem more vulnerable to bronchogenic carcinoma and improvement in regional perfusion status was revealed to be more difficult than that in regional ventilation status after treatment.

Adult↗

[A study on resource based relative values for visiting nursing services].

PURPOSE: The purpose of this study was to investigate the resource based relative values of visiting nursing services, and to analyze the relationships between the relative values and the dimensions of nursing service(time, mental effort and physical effort). METHODS: We interviewed nurses at 20 Home-visit nursing care stations (HVNCS) in the Metropolitan area using the resource based relative value questionnaires. We asked nurses about relative values of "Total Work", and also measured relative weight of 3 dimensions of nursing services. Total Work was defined as comprehensive evaluation of nursing services, with careful consideration of intensity as well as duration. With the dependent variable as Total Work and independent variables as the 3 dimensions, multiple regression analyses were carried out. Furthermore we examined the degree of influence on Total Work by service type and individual respondent. To examine the validity of the results, we timed nursing services and compared the measured time with the answered time. RESULTS: The 107 respondents were all female and their average age was 36.6 years old. They had HVNCS experience of 2.2 years and 95.3% nurses had experience of hospital nursing. "Total Work" and 3 dimension scores were standardized using common logarithms. "Total Work" of every service significantly differed among service types. The 3 dimensions explained 54.6% of Total Work in the multiple regression analysis. Service type explained 3.3% of Total Work. Individual respondent explained 16.0% of Total Work. Answered time and measured time were not significantly different with nursing services. CONCLUSIONS: Although Total Work was somewhat influenced by individual respondent, most of variation was explained by 3 dimensions. Thus, it could be concluded that Total Work is an index of nursing resource input. A further investigation about influence of patients' condition on Total Work is necessary in the future.

Adult↗

Early tumor growth in metastatic organs influenced by the microenvironment is an important factor which provides organ specificity of colon cancer metastasis.

We have previously demonstrated that liver metastases in nude mice and lung metastases in nude rats occurred specifically, when KM12SM human colon carcinoma cells were inoculated orthotopically into the cecal wall of nude mice and rats. To clarify the relationship between the tumor growth potential in the metastatic organs and the metastatic organ preference in these two metastatic models, we have evaluated the in vitro cell growth activities affected by the organ conditioned medium (CM) from the liver and lung, and the in vivo growth activities of the ectopic implanted tumors in the liver and lung. The tumorigenicity of the ectopic implanted tumors was 100% in mouse liver, 33% in rat liver, 50% in mouse lung, and 75% in rat lung. The crude liver CM of the animals showed inhibitory activities for KM12SM cell growth in a dosage-dependent manner, and the crude lung CM stimulated KM12SM cell growth. The liver CM of nude mice inhibited the KM12SM cell growth more strongly compared with the CM of nude rats, and the lung CM of nude rats was more strongly stimulated compared with the CM of nude mice. The liver CM of nude mice had non-heparin binding factors, which stimulated or inhibited KM12SM cell growth, in a molecular weight range of 50 to 100 kDa. By contrast, the liver CM of nude rats showed no growth stimulating activity for KM12SM cells. These results suggest that the metastatic organ specificity of KM12SM cells may depend on the early tumor growth influenced by the microenvironment in metastatic organs.

Animals↗

Mechanism of DNA gyrase-mediated illegitimate recombination: characterization of Escherichia coli gyrA mutations that confer hyper-recombination phenotype.

To study the mechanism of DNA gyrase-mediated illegitimate recombination in Escherichia coli, we isolated temperature-sensitive gyrA mutants that confer spontaneous illegitimate recombination and spontaneous induction of lambda prophage at higher frequencies than that in the wild-type. After reconstruction of single mutations by targeted mutagenesis, we confirmed that two single mutations, gyrAL492P and gyrAL488P, and a double mutation, gyrAI203V+gyrAI205V, show the same properties as those described above. With respect to the phenotypes of hyper-recombination and higher induction of lambda prophage, these mutations were dominant over the wild-type. Analysis of recombination junctions of lambdabio transducing phages formed spontaneously in these mutants showed that the parental E. coli bio and lambda recombination sites have a homologous sequence of only 0. 7 base-pair on average, indicating that homology is not required for this illegitimate recombination. Analysis of nucleotide sequences of mutant gyrA genes revealed that the gyrAL492P and gyrAL488P mutations contain amino acid substitutions of Leu492-->Pro and Leu488-->Pro, respectively, which correspond to the alpha18 helix in the breakage-reunion domain of DNA gyrase A subunit. The gyrAI203V and gyrAI205V mutations contain Ile203-->Val and Ile205-->Val, respectively, which correspond to the alpha10' helix, also in the breakage-reunion domain of DNA gyrase A subunit. Biochemical analysis indicated that the GyrA63 protein that contains the L492P mutation has an apparently normal supercoiling activity, but it also produces a small amount of linear DNA in the absence of DNA gyrase inhibitor during the supercoiling reaction, suggesting that the mutant DNA gyrase may have a defect at the step of religation or a defect in the subunit interaction. These results suggest that the recombination is induced by defects of religation and/or dimer formation in the mutant DNA gyrases, implying that two alpha helices, alpha10' and alpha18, of DNA gyrase A subunit have crucial roles in subunit interaction and/or resealing of DNA.

Alleles↗

A novel role of IL-15 in the development of osteoclasts: inability to replace its activity with IL-2.

IL-15 shares many activities with IL-2 on stimulating lymphocytes, hematopoietic progenitor cells, and macrophages. However, the role of IL-15 in osteoclastogenesis has not been elucidated. The recent finding of abundant IL-15 in rheumatoid arthritis synovial fluids suggested a possible role for this cytokine in the pathological destruction of bone and prompted us to determine whether IL-15 stimulates osteoclast formation. IL-15 stimulated the formation of multinucleated osteoclast-like cells in rat bone marrow cultures. In stroma-free cultures, IL-15 increased the number of mononuclear preosteoclast-like cells in the early stage of osteoclast formation. The stimulation was observed even after treatment with IL-15 for only 24 or 48 h of culture. Moreover, low IL-15 concentration (0.1 ng/ml) strongly increased the level of calcitonin receptor mRNA of mononuclear preosteoclast-like cells. Although IL-15 is known as a potent stimulator of TNF-alpha, its activity was not abolished by addition of anti-TNF-alpha Ab. Interestingly, IL-2 and IL-7, which utilize some IL-15R components, had no effect on osteoclast differentiation, but pretreatment with IL-2 or IL-7 of bone marrow cells before the addition of IL-15 inhibited the enhancing activity of IL-15. In summary, IL-15 has a novel activity to stimulate the differentiation of osteoclast progenitors into preosteoclasts, which cannot be replaced by IL-2 but may use components in common with IL-2R to mediate its effects.

Animals↗

The prognostic significance of lymph node metastasis and intrapancreatic perineural invasion in pancreatic cancer after curative resection.

To investigate the prognostic factors of pancreatic cancer, a retrospective analysis of 193 patients who underwent curative resection was conducted. Of the 193 patients, 38 (20%) survived for more than 5 years, the 5-year survival rates for stages I, II, II, and IV disease being 41%, 17%, 11%, and 6%, respectively. According to a multivariate analysis, lymph node metastasis, intrapancreatic perineural invasion, and portal vein invasion were significant prognostic factors. Subsequently, a subgroup analysis concerning nodal metastasis and intrapancreatic perineural invasion was performed in 126 patients with records of these histological findings. In the group of patients without nodal metastasis, the 5-year survival rate for those without perineural invasion was 75%, whereas that for those with perineural invasion was 29%, the difference in survival of these subgroups being significant (P < 0.02). In the group of patients with nodal metastasis, the 5-year survival rate for those without perineural invasion was 17%, while that for those with perineural invasion was 10%. The most favorable 5-year survival of 89% was observed in the subgroup of patients with stage I disease without perineural invasion. Thus, pancreatic adenocarcinoma categorized by the combination of these independent types of biological behavior showed 5-year survival rates ranging from very high to low, indicating that these two factors play an important role in the prognosis of this disease.

Adenocarcinoma↗

Expression of mRNA encoding tissue-nonspecific alkaline phosphatase in human dental tissues.

Tissue-nonspecific-type alkaline phosphatase (TNSALP) is found in the bone, liver, kidney, and other tissues, and its gene consists of 12 exons with the coding sequence beginning in the second exon. Recently, a noncoding first exon was identified in the liver message (liver type) which differed from that of the previously known osteoblast-derived cDNA sequence (bone type). Although these two mRNAs produce an identical protein, they have different promoter regions. It is known that ALPs in dental pulp and periodontal ligament are classified into TNSALP by their enzymatic and immunological properties, but little is known about the expression of ALP mRNAs and the transcriptional mechanisms. In order to examine the expression of their mRNA type, specific oligonucleotide primers corresponding to two types of mRNAs of human TNSALP were designed and amplified by reverse transcription-polymerase chain reaction (RT-PCR). It was found that bone-type mRNA was expressed in the human dental tissues such as dental pulp, periodontal ligament, and dental sac, whereas liver-type mRNA was not expressed. Thus, it was concluded that the human dental tissues express the bone-type isozymes and are regulated by the same transcriptional mechanism as in the bone.

Alkaline Phosphatase↗

Involvement of prostaglandins in histamine H1 receptor-operated Ca2+ entry in human gingival fibroblasts.

In the absence of external Ca2+, 100 microM histamine evoked a transient increase in intracellular Ca2+ ([Ca2+]i), and subsequent addition of Ca2+ to the medium resulted in a sustained increase in [Ca2+]i in fura-2-loaded human gingival fibroblasts. These Ca2+ mobilizations are attributed to Ca2+ release from intracellular stores and Ca2+ entry, respectively. When the histamine H1 antagonist chlorpheniramine was added after the histamine-induced transient increase in [Ca2+]i, the Ca2+ entry induced by the addition of Ca2+ was inhibited. In the fibroblasts pretreated with cyclooxygenase inhibitors, indomethacin (1 microM) or aspirin (100 microM), histamine-induced Ca2+ entry was significantly inhibited, but not the transient [Ca2+]i increase. These results suggest that the histamine-induced Ca2+ entry requires the continuous binding of histamine to the H1 receptors and is regulated by prostaglandins, which are probably produced due to the H1 receptor activation.

Aspirin↗

Study of the gerbil utricular macula following treatment with gentamicin, by use of bromodeoxyuridine and calmodulin immunohistochemical labelling.

Effects of ototoxic drugs on the gerbil vestibular sensory epithelium were probed by use of immunocytochemical labelling with antibodies to both a mitogenic marker (bromodeoxyuridine) and a hair cell specific protein (calmodulin). Nine animals had gentamicin administered once daily for 5 days, as a transtympanic injection into the right middle ear. They additionally were given a daily intraperitoneal injection of bromodeoxyuridine, starting on the same day as the gentamicin injection and continuing until the day of sacrifice. Nine other animals, serving as controls for bromodeoxyuridine incorporation, received only the intraperitoneal injections of bromodeoxyuridine. The inner ears from three gerbils were obtained at 1, 2 or 4 weeks following the last gentamicin injection and utricles from the injected ears were processed for immunohistochemical analysis. In specimens where gentamicin was administered, we found evidence of bromodeoxyuridine incorporation in 17 cells (10 single cells and 7 pairs of cells) in a total of 216 sections taken from the central regions of the 9 utricles. However, in control specimens, no bromodeoxyuridine labelling was found in any cells of the 216 sections examined. Of 10 single cells labelled with bromodeoxyuridine, two cells in the hair cell layer were labelled with antibodies against calmodulin. One had a faint labelling in the nucleus and the other in the stereocilia, but not in the cell bodies. Of 7 pairs of cells, two pairs with nuclei localized in the hair cell layer had faint labelling for calmodulin in the nuclei, but no labelling in any other part of the cell. The other 13 cells labelled with antibodies to bromodeoxyuridine were not labelled with antibodies to calmodulin. Our results suggest that the bromodeoxyuridine-labelled cells could not be positively identified as hair cells based on immunohistochemical labelling for calmodulin.

Acoustic Maculae↗

Evaluation of pylorus-preserving pancreatoduodenectomy with the Imanaga reconstruction by hepatobiliary and gastrointestinal dual scintigraphy.

BACKGROUND: Following pylorus-preserving pancreatoduodenectomy (PPPD), most surgeons use gastrointestinal reconstruction with an end-to-side duodenojejunostomy placed distally to the pancreatojejunostomy and choledochojejunostomy. In contrast, the authors have consistently used PPPD with the Imanaga reconstruction (PPPD-Imanaga) which consists of end-to-end duodeno- jejunostomy, end-to-side pancreatojejunostomy and choledochojejunostomy, performed in that order. In this study, the movement of bile and food after PPPD-Imanaga was evaluated to document the functional advantages of this method. METHODS: Twenty-four patients who had undergone PPPD-Imanaga were subjected to hepatobiliary and gastrointestinal dual scintigraphy. The interval between operation and scintigraphy ranged from 28 days to 67 months. Six of the 24 patients underwent repeated dual scintigraphy for the observation of temporal changes in gastrointestinal function. RESULTS: The incidence of biliogastric reflux and bile stasis in the jejunal loop was markedly decreased at times later than 2 months after operation. Delay of gastric emptying and bile evacuation, sometimes accompanied by stasis in the jejunal loop, affected the mixing status of bile and food at 1 h after the beginning of imaging. A majority of the patients, however, had a satisfactory mixing status at 2 h. CONCLUSION: The Imanaga reconstruction appears to be a recommendable procedure following PPPD, in light of the bile and food movement achieved in the gastrointestinal tract.

Adult↗

Intrauterine growth retardation as a cause of perinatal mortality in Japanese black beef calves.

Perinatal death is one of the major causes of calf mortality in Japanese Black beef herds. A series of experiments were carried out to determine causes of perinatal calf mortality in a region of northern Japan. An aetiological survey revealed that the incidence of perinatal mortality in 6475 calves was 4.5% and the majority of neonatal deaths were caused by weak calf syndrome. The weak calves delivered after a normal gestation period had a significantly lower body weight at birth than normal calves (P < 0.01), indicating growth retardation in the uterus during pregnancy. Haematological and histopathological examinations showed that the weak calves had anaemia characterized by a significant decrease of blood cell values and bone marrow hypofunction. The anaemia due to bone marrow hypofunction presumably caused intrauterine growth retardation of the foetus. Dams delivering the weak calves showed significantly lower serum concentrations of estrone sulphate during late pregnancy than those with normal calves (P < 0.01), indicating foeto-placental dysfunction as a possible cause of growth retardation. Effects of sires as well as the maternal family on the incidence of neonatal death and on the rate of weak calves in dead neonates were found in the survey. Intrauterine growth retardation associated with anaemia may be the most important cause of weak calf syndrome in Japanese Black beef calves. The bull and maternal family may also have an influence on the incidence of neonatal death.

Anemia↗

Increased expression of TGF-beta1 but not of its receptors contributes to human obstructive nephropathy.

UNLABELLED: Increased expression of TGF-beta1 but not of its receptors contributes to human obstructive nephropathy. BACKGROUND: Previous studies have revealed an increased expression of transforming growth factor-beta1 (TGF-beta1) and deposition of extracellular matrix in the kidney of animals with ureteral obstruction. However, these relationships have not been elucidated in the hydronephrotic kidney of humans. METHODS: We analyzed the tissue expression of extracellular matrix proteins, TGF-beta1, and its receptors in the human kidney with ureteral obstruction by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Obstructed kidneys (OBKs) were obtained from patients with ureteral tumors. A kidney specimen from patients with a renal tumor was used as control (CNKs). RESULTS: The interstitial volume was significantly increased in OBKs in comparison with CNKs. OBKs showed increased deposition of collagen types I and IV and fibronectin in the renal interstitium. RT-PCR revealed overexpression of collagen alpha1(IV) mRNA and fibronectin mRNA in OBKs. OBKs showed a significantly increased mRNA expression of TGF-beta1 in comparison with CNKs. The immunoreactivity for TGF-beta1 increased markedly in the interstitium of OBKs. There was a significant correlation between the TGF-beta1 mRNA level and the interstitial volume. However, there was no significant difference between OBKs and CNKs in the relative mRNA level nor in immunoreactivity for TGF-beta receptors. CONCLUSIONS: These data suggest that TGF-beta1 may contribute to the interstitial fibrosis found in the human kidney with ureteral obstruction, mainly because of an increase in the expression of this cytokine without significant changes to its receptors.

Activin Receptors, Type I↗

Analysis of a catalytic pathway via a covalent adduct of D52E hen egg white mutant lysozyme by further mutation.

We previously demonstrated by X-ray crystallography and electrospray mass spectrometry that D52E mutant hen lysozyme formed a covalent enzyme-substrate adduct on reaction with N-acetylglucosamine oligomer. This observation indicates that D52E lysozyme may acquire a catalytic pathway via a covalent adduct. To explain this pathway, the formation and hydrolysis reactions of the covalent adduct were investigated. Kinetic analysis indicated that the hydrolysis step was the rate-limiting step, 60-fold slower than the formation reaction. In the formation reaction, the pH dependence was bell-shaped, which was plausibly explained by the functions of the two catalytic pKas of Glu35 and Glu52. On the other hand, the pH dependence in the hydrolysis was sigmoidal with a transition at pH 4. 5, which was identical with the experimentally determined pKa of Glu35 in the covalent adduct, indicating that Glu35 functions as a general base to hydrolyze the adduct. To improve the turnover rate of D52E lysozyme, the mutation of N46D was designed and introduced to D52E lysozyme. This mutation reduced the activation energy in the hydrolysis reaction of the covalent adduct by 1.8 kcal/mol at pH 5.0 and 40 degrees C but did not affect the formation reaction. Our data may provide a useful approach to understanding the precise mechanism of the function of natural glycosidases, which catalyze via a covalent adduct.

Animals↗