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Biomedical subjects

N Yahagi

Publications and source records attributed to N Yahagi.

At least 109 records · Page 6Linked to original sources
PubMed1994

[Inhaled nitric oxide after Fontan type operation].

The indication of Fontan type operation has been extending, but some cases on the boundary of the indication resulted in low cardiac output syndrome (LOS) postoperatively. Recently the inhalation of nitric oxide (NO) has been revealed to produce selective pulmonary vasodilatation, and it has come to be applied in the clinical setting. We experienced a case of 6-year-old boy with complex cardiac anomaly in whom the inhalation of nitric oxide was remarkably effective for the LOS caused by increased pulmonary vascular resistance after Fontan type operation. In the case various conventional treatments failed to improve his LOS during the weaning from a respirator on the second postoperative day. After the initiation of the inhalation of nitric oxide at a concentration of 6ppm, a rapid decreasing of pulmonary artery pressure concomitant with an improvement of hemodynamics were obtained. We concluded that the inhalation of nitric oxide is an effective strategy for the increased pulmonary resistance after Fontan type operation.

Administration, Inhalation↗
PubMed1993

Effects of omeprazole on gastric mucosal growth and differentiation in developing rat.

The effects of omeprazole on developing rat stomach mucosa were investigated. Infant rats were given subcutaneous injections of either omeprazole (25 mg/kg body weight/day) or vehicle once a day from the day after birth. As a result, omeprazole caused an elevation of mucosal pH and suppressed an increase in mucosal pepsinogen and its mRNA levels during stomach development. Histologically, these changes were associated with a reduction in mature pepsinogen-producing cells throughout stomach mucosa. Omeprazole also caused a delay in the expression of cathepsin E in surface mucous cells and an increase in labeled cells with bromodeoxyuridine. Thus, the present results indicate that omeprazole induces an increase in mucosal cell proliferation and delays the differentiation of developing rat stomach mucosa. Since the observed changes were remarkable especially from days 15 to 21 after birth when significant development of acid secretion occurs, the effects of omeprazole appear to be related with the potent acid inhibitory effect of the reagent.

Aging↗
PubMed1993

Omeprazole, a proton pump inhibitor, reduces the secretion, synthesis and gene expression of pepsinogen in the rat stomach.

Omeprazole, a proton pump inhibitor, dose-dependently inhibited pepsinogen secretion as well as acid secretion in the rat glandular stomach. The reduction in the secretion was rapid and was followed by a decrease in the mRNA levels. The inhibitory effect of omeprazole on pepsinogen secretion and its effect on the mRNA level showed similar dose-response relationship, suggesting that pepsinogen secretion and the gene expression are regulated coordinately. Consistent with the reduction in the mRNA levels, protein synthesis was reduced. However, intracellular stores of pepsinogen increased in pepsinogen-producing cells, indicating that the inhibitory effect of omeprazole on pepsinogen secretion is greater than on its synthesis. Reducing the secretion, synthesis and gene expression of pepsinogen, omeprazole has a potent effect on pepsinogen-producing cells in vivo, as well as on parietal cells, in the rat glandular stomach.

Animals↗
PubMed1993

Clinical application of serum pepsinogen I and II levels for mass screening to detect gastric cancer.

A considerable number of gastric cancers derive from stomach mucosa where chronic atrophic gastritis is severe and extensive. Based on the fact that the serum pepsinogen levels provide a precise measure of the extent of chronic atrophic gastritis, we have devised a mass screening method involving serum pepsinogen measurement to identify subjects at high risk of gastric cancer. In 1991, we screened 4,647 workers (male: 4,113, female: 534, mean age: 49.0 years) at a Japanese company using this method. Out of 875 subjects (18.8%) with a serum pepsinogen I level of less than 50 micrograms/liter and a pepsinogen I/II ratio of less than 3.0, 676 subjects (14.5%) were selected for further investigation by endoscopy. This led to the detection of four subjects (0.086%) with gastric cancer (three in an early stage) and four subjects with adenoma. The cancer detection rate of this new screening method was comparable, and in some respects superior, to that of the traditional barium X-ray screening. Since the incidence of test-positive subjects was as low as 10% amongst subjects aged less than 40, this screening method appears to be especially useful for screening of younger generations. The new method is less expensive than the traditional barium X-ray and subjects experience little discomfort. Further, many serum samples can be quickly measured simultaneously. The results of this study have indicated that serum pepsinogen screening provides a valuable method for detecting gastric cancers.

Adenoma↗
PubMed1993

Characteristics of a 28-kDa collagenous protein extracted with guanidine from EDTA-demineralized rabbit alveolar bone.

Bone proteins in alveolar bone of mandibles from young adult rabbits (3-month-old) were extracted with 4.0 M guanidine hydrochloride (GuHCl), followed by 0.5 M ethylenediaminetetraacetate, and again with 4.0 M GuHCl (G2-ext). The proteins in the G2-ext were fractionated on a gel-filtration column, followed by an anion-exchange column in the presence of 7.0 M urea. A 28-kDa protein was isolated from the G2-ext. The purified 28-kDa protein showed intense staining with silver on SDS-PAGE slab-gel under reducing conditions. This protein was digested with bacterial collagenase, and a 19-kDa fragment appeared on the gel. However, the protein was not susceptible to reduction with cyanogen bromide. The protein did not bind to hydroxyapatite crystals in the presence of 7.0 M urea, and also did not bind to some lectins. On SDS-PAGE under non-reducing conditions, the protein migrated as two bands; a new band appeared at approximately the 85-kDa region in addition to the original 28-kDa band. The amino acid compositions of the protein were similar to those of the alpha 1-pN-propeptide of type I procollagen obtained from other tissues.

Alveolar Process↗
PubMed1993

Low temperature dependent IgG3 subclass antibody with low avidity to C100-3 antigen derived from hepatitis C virus in voluntary blood donors.

The presence of an antibody which reacts strongly at lower temperatures to C100-3 antigen derived from the hepatitis C virus (HCV) was demonstrated in blood donors' sera. These sera reacted with the antigen most strongly at 4 C and most weakly at 37 C and are termed 'cold antibody group'. The cold antibody group reaction was specifically inhibited with soluble C100-3 antigen. Cold antibody bound to C100-3 antigen at 4 C was dissociated at 37 C and was isolated in this manner. Low temperature-dependent anti C100-3 antibody was shown to be predominantly IgG3 subclass by ELISA using anti-human IgG subclass antibody. This IgG3 antibody was dissociated from antigen with 6M urea, demonstrating its low avidity. HCV-RNA was demonstrated in two of five samples. Therefore, to achieve more effective prevention of post-transfusion hepatitis C, we propose the incorporation of programs to detect low temperature-dependent low-avidity antibody against HCV-related antigen.

Antibody Affinity↗
PubMed1992

Flow cytometric analysis on perforin induction in peripheral blood mononuclear cells with interleukin-2 or OK-432.

Perforin is a protein present in the cytoplasmic granules of killer cells and is considered to be an important effector molecule. We assessed the perforin appearance via flow cytometry in human peripheral blood mononuclear cells stimulated in vitro for 3 days by recombinant interleukin-2 (rIL-2) or OK-432, a biological response modifier. The relationship between the lymphocyte subsets and perforin was investigated via two-color assay. CD4-positive cells had almost no perforin, and most of the CD16-positive cells did. Regarding the relationship with CD8, some of the bright positive cells (which were likely T cells) and most of the dull positive cells (likely NK cells) had perforin. Mean fluorescence was greatest in perforin-positive cells incubated with rIL-2, less in cells incubated with OK-432, and minimal in cells incubated in a medium without additives. Immunohistochemical staining with antiperforin antibody revealed that blast-transformed and enlarge cells were stained positively and that the intensity of staining of each cell alone was enhanced in cells incubated with OK-432 or rIL-2. If the fluorescence intensity of perforin-positive cells correlates with the amount of perforin in those cells, then the appearance of perforin was enhanced with OK-432, more enhanced with rIL-2, and consistent for cytotoxicity against K562 and Daudi cells. IL-2 was induced by OK-432, suggesting that the indirect effect of this IL-2 may play a role in OK-432-perforin induction. The results suggest that perforin may be an effector molecule in killer cells induced by rIL-2 or OK-432.

Cytotoxicity, Immunologic↗
PubMed1992

Pituitary apoplexy following cholecystectomy.

A case of pituitary apoplexy, which presented with hyperaesthesia in the distribution of the ophthalmic division of the left trigeminal nerve and a left sixth nerve palsy following cholecystectomy, is reported. Computed tomography and magnetic resonance imaging revealed a large intrasellar mass which extended laterally into the left cavernous sinus and showed evidence of old and recent haemorrhage within the tumour. This case demonstrates that patients who present with unusual neurological symptoms involving the cranial nerves after general anaesthesia, should undergo neurological and radiological investigations.

Analgesia, Epidural↗
PubMed1992

Effect of halothane, fentanyl, and ketamine on the threshold for transpulmonary passage of venous air emboli in dogs.

We assumed that the capacity of the lungs to filter gas bubbles would vary as a function of anesthetic management. The effects of halothane (1% inspired concentration [group 1, n = 8]), fentanyl (100 micrograms/kg IV, followed by 1 micrograms.kg-1.min-1 [group 2, n = 7]), and ketamine (10 mg/kg IV, followed by 0.2 mg.kg-1.min-1 [group 3, n = 6]) on the passage of bolus injections of air across the pulmonary circulation were studied in dogs by using transesophageal echocardiography to detect air in the left atrium or the aorta, or both. The thresholds for bolus air detection during halothane, fentanyl, and ketamine administration were 0.05 mL/kg (range 0.01-0.1), 0.5 mL/kg (range 0.2-1.0), and 0.35 mL/kg (range 0.1-0.5), respectively. We conclude that the threshold during fentanyl- or ketamine-induced anesthesia was significantly higher than during halothane-induced anesthesia. Therefore, halothane interferes with the capacity of the lungs to filter air from the pulmonary circulation.

Animals↗
PubMed1991

The influence of upper respiratory tract surgery on respiratory function evaluated by oxygen saturation.

To evaluate the influence of upper respiratory tract surgery on respiratory function, we used a pulse oximeter to measure the arterial oxygen saturation in 40 patients (ASA 1 or 2) during surgery under local anesthesia. The patients were divided into four groups: a control group of 10 patients who underwent surgery not involving the upper respiratory tract, and three upper respiratory tract surgery groups of 10 patients each underwent surgery on the nasal cavity alone (group 1), on the oral cavity alone (group 2), and on both the oral and nasal cavities (group 3). Groups 1 and 2 showed little desaturation compared to their baseline levels and the control group, while group 3 showed a mild desaturation even at the beginning of surgery and this gradually turned to a moderate or severe desaturation. This was due to both the extension of the surgical zone to the nasal and oral cavities and to ventilatory distress produced by massive bleeding and aspiration of secretions. Thus, the pulse oximeter is a useful monitor for upper respiratory tract surgery involving both general and local anesthesia. It allows the identification of hypoxia so that remedial therapy can be instituted.

Journal Article↗
PubMed1991

[HCV antibody test methods and patterns of antibody response].

The sensitivity and specificity of the second generation ELISA (2nd ELISA) and RIBA (2nd RIBA) using c 22 and c 200 or c 33 c recombinant antigens encoded in the core and NS 3 of HCV genome have been evaluated preclinically by Ortho and Chiron (USA). Sensitivity of the assay was evaluated by determining the reactivity of 2nd ELISA and RIBA in the following panels: NANBH (N = 35) and high risk groups composed of: hemophiliacs (N = 50), IVDA (N = 50) and renal dialysis cases (N = 279). In the reactive specimens, antibody response to both c 33 c and c 22-3 was present in 93-100% whereas antibody response to 5-1-1 and c 100-3 was seen in 46-84% of these same specimens. Specificity, in turn, was evaluated using 2000 volunteer donors of 29 (1.45%) 2nd ELISA positives, 16/29 (55.2%) were confirmed by 2nd RIBA and 8/29 (27.6%) were 1 band positive (indeterminate), whereas of 27 (1.35%) 1st ELISA positive, 9/27 (33.3%) were confirmed and 4/27 (14.8%) were 1 band positive by 1st RIBA (c 100-3, 5-1-1). The relevance of various band patterns and correlation between PCR positivity with 2nd RIBA reactivity are discussed. The consistency and sensitivity of the 2nd RIBA evaluated using a densitometer are also reported.

Antigens, Viral↗
PubMed1991

[Interpretation of Ortho HCV Ab ELISA test results by chiron HCV recombinant immunoblot assay].

HCV infections are diagnosed by determining the circulating antibodies to the C 100 recombinant viral antigen using the ELISA method. Cut-off analysis from normal subjects and well documented NANBH patients suggests that screening of a low risk group such as blood donors might yield a relatively high ratio of false positives. An immunoblot assay (Chiron RIBA) using 3 recombinant antigens, C 100, 5-1-1 and SOD has been developed for evaluating the ELISA reactives as an additional, more specific assay. In the RIBA testing 51.5% were reactive and 28.5% were indeterminate in ELISA positive donor specimens, and 79.5% were reactive and 8.0% were indeterminate in ELISA positive non-A, non-B hepatitis patients specimens. These findings coincide with the ratio of theoretically calculated true positive. In a study done by Ortho U.S.A. viral RNA were detected in 70% of RIBA reactive, 33% of indeterminate and 3.6% non-reactive specimens by polymerase chain reaction (PCR). Furthermore, an advanced system using another immunogenic region of viral polyprotein including c33c encoded in NS3 has been on trial to evaluate the possibility of confirming HCV infection and detecting seroconversion at an earlier stage.

Antigens, Viral↗
PubMed1991

[Effect of halothane, fentanyl and ketamine on the threshold for the passage of venous air embolism through lungs in dogs].

Effect of halothane, fentanyl and ketamine on the passage of air injected bolus across the pulmonary circulation was studied in dogs using transesophageal M-mode echocardiography. Dogs in Group 1 (N = 5) were anesthetized with halothane and then halothane with fentanyl. At least 3 weeks later the dogs were anesthetized with fentanyl and then fentanyl with halothane. The same procedure was utilized in group 2 (N = 4) using halothane and ketamine. The doses of halothane, fentanyl and ketamine were 1% inspired concentration, 100 micrograms.kg-1 followed by 1 microgram.kg-1.min-1 iv, and 10 mg.kg-1 followed by 0.1 mg.kg-1.min-1 iv, respectively. The threshold for bolus air detection during halothane, fentanyl and ketamine alone were 0.05, 0.5 and 0.2 ml.kg-1, respectively. The threshold during fentanyl administration, but not during ketamine administration, was significantly higher than that during halothane. The addition of halothane to fentanyl or ketamine lowered the threshold to the same level as with halothane alone, and the addition of either fentanyl or ketamine to halothane made no difference. Although there was no difference in baseline shunt fraction resistance index [PVRI/(Qs/Qt)] during administration of each anesthetic, every air injection decreased shunt fraction resistance index during halothane without fentanyl or during halothane with or without ketamine, and increased it during fentanyl administration.

Animals↗