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Biomedical subjects

T Noguchi

Publications and source records attributed to T Noguchi.

At least 487 records · Page 27Linked to original sources
PubMed1994

Endoscopic ligation of gastric varices using a detachable snare.

A new technique of endoscopic treatment for gastric varices is presented here, which was applied in 10 patients, either electively (n = 9) or as emergency therapy for bleeding (n = 9) or as emergency therapy for bleeding (n = 1). A detachable snare is placed endoscopically, tightened around the varix, and then detached using a similar principle to that of band ligation. Following one or two treatment sessions (one snare applied in seven cases, two snares applied in three cases), eradication of gastric varices was observed in all patients. No significant complications were encountered, and nine of 13 snares passed spontaneously, the remaining ones being removed when found during follow-up endoscopy. Short-term follow-up (4-12 months, mean: 7.2 months) did not show either reappearance of varices or rebleeding in any of the patients. Angiography and endoscopic ultrasonography performed in four patients before and after treatment showed regression or disappearance of intramural vessels. Further studies will show the relative value of this new technique compared to other treatment modalities such as banding or cyanoacrylate injection.

Aged↗
PubMed1994

Gas gangrene following sacral pressure sores.

We report two cases of gas gangrene developed from sacral pressure sores. The first case was clostridial and the second, non-clostridial gas gangrene. Both patients died within two months. The first patient, a 56-year-old woman suffering from palsy of the lower half of the body for 3 weeks, developed a sacral pressure sore. One month later, crepitus by palpation and gas formation in the X-ray film were detected in the hip and right thigh. A culture of odoriferous pus yielded Clostridium limosum in addition to Staphylococcus intermedius, Enterococcus faecalis, Pseudomonas aeruginosa, and Bacteroides fragilis. Blood culture yielded Bacteroides fragilis. The patient died 50 days after admission in spite of surgical debridement and aggressive therapy with high doses of antibiotics and hyperbaric oxygen. The second patient, a 70-year-old man suffering from diabetic nephropathy, arteriosclerosis obliterans of the lower limbs, and cerebral infarction, developed a large decubitus ulcer covering the whole sacral area. Crepitus and gas were detected in the soft tissue of the left gluteal region. Almost the entire gluteus maximus muscle was necrotic. Bacteroides fragilis, methicillin-resistant or -sensitive Staphylococcus aureus and Escherichia coli were isolated from the muscle. Bacteroides fragilis was also obtained by blood culture. The patient died on the 72nd day after admission.

Aged↗
PubMed1994

Collagenase activity and tissue inhibitor of metalloproteinases-1 (TIMP-1) content in human whole saliva from clinically healthy and periodontally diseased subjects.

Total TIMP-1 concentration in whole saliva of periodontally diseased subjects, 137 +/- 67 ng/ml (mean +/- SD), was clearly lower (p < 0.001) than that of clinically healthy subjects, 273 +/- 145, and that of edentulous subjects, 332 +/- 121. On the contrary, both active [1.58 +/- 0.35 units/ml (mean +/- SD)] and total (2.08 +/- 0.25) collagenase activities in TIMP-1-free whole saliva of diseased subjects were significantly higher than the activities (0.14 +/- 0.14 and 0.50 +/- 0.27, respectively) in TIMP-1-free whole saliva of healthy subjects. Most of the total collagenase in whole saliva of healthy subjects consisted of procollagenase, while mainly active collagenase was present in whole saliva from patients with periodontal diseases. Significant reciprocal changes of TIMP-1 and collagenase levels, that is, increase in TIMP-1 concentration and decrease in collagenase activity, were observed after the initial therapy of periodontitis patients.

Adolescent↗
PubMed1994

Effect of long-term methotrexate-induced neutropenia on experimental periodontal lesion in rats.

The effects of long-term methotrexate (MTX)-induced neutropenia on the periodontal lesion in rats were investigated histologically, histometrically and bacteriologically. A nylon thread was inserted into the interdental gingiva between the 1st and 2nd right maxillary molars of the animals 3 weeks before an application of MTX. The animals were then divided into Groups A and B. Group B were injected intraperitoneally with 1.0 mg/kg of MTX 3 times per week for 9 weeks. Group A received saline as a control. Five animals were killed at the 1st, 3rd, 5th, 7th, and 9th week. In Group A, the neutrophils did not decrease during these 9 weeks. In Group B, however, the neutrophils decreased during the 3rd to 9th week. Whereas the experimental side of Group A showed only moderate alveolar bone resorption between the 7th and 9th week, [in Group B] a marked alveolar bone resorption occurred in Group B occurred in the same period. Alveolar bone loss in the experimental side of Group B was significantly greater (p < 0.01) than in Group A in the 7th to 9th weeks. The percentage of gram-negative rods increased in both control and experimental sides of Group at the 9th week. The results of the present study indicate that neutropenia is induced by a long-term application of MTX in rats and that alveolar bone destruction increases as time goes by in the area where a nylon thread was inserted.

Alveolar Bone Loss↗
PubMed1994

Role of SH-PTP2, a protein-tyrosine phosphatase with Src homology 2 domains, in insulin-stimulated Ras activation.

SH-PTP2 is a nontransmembrane human protein-tyrosine phosphatase that contains two Src homology 2 (SH2) domains and binds to insulin receptor substrate 1 (IRS-1) via these domains in response to insulin. The expression of a catalytically inactive mutant of SH-PTP2 (containing the mutation Cys-459-->Ser) in Chinese hamster ovary cells that overexpress human insulin receptors (CHO-IR cells) markedly attenuated insulin-stimulated Ras activation. Expression of mutant SH-PTP2 also inhibited MAP kinase activation in response to insulin but not in response to 12-O-tetradecanoyl phorbol-13-acetate. In contrast, the insulin-induced association of phosphoinositide 3-kinase activity with IRS-1 was not affected by the expression of inactive SH-PTP2. Furthermore, the expression of mutant SH-PTP2 had no effect on the binding of Grb2 to IRS-1, on the tyrosine phosphorylation of Shc, or on the formation of the complex between Shc and Grb2 in response to insulin. However, the amount of SH-PTP2 bound to IRS-1 in insulin-treated CHO-IR cells expressing mutant SH-PTP2 was greater than that observed in CHO-IR cells overexpressing wild-type SH-PTP2. Recombinant SH-PTP2 specifically dephosphorylated a synthetic phosphopeptide corresponding to the sequence surrounding Tyr-1172 of IRS-1, a putative binding site for SH-PTP2. Additionally, phenylarsine oxide, an inhibitor of protein-tyrosine phosphatases, inactivated SH-PTP2 in vitro and increased the insulin-induced association of SH-PTP2 with IRS-1. These results suggest that SH-PTP2 may regulate an upstream element necessary for Ras activation in response to insulin and that this upstream element may be required for the Grb2- or Shc-dependent pathway. Furthermore, these results are consistent with the notion that SH-PTP2 may bind to IRS-1 through its SH2 domains in response to insulin and dephosphorylate the phosphotyrosine residue to which it binds, thereby regulating its association with IRS-1.

Adaptor Proteins, Signal Transducing↗
PubMed1994

Effect of pulmonary blood flow on microvascular pressure profile determined by micropuncture in perfused cat lungs.

To clarify the role of the pulmonary microvasculature in adjusting to increased pulmonary blood flow, we measured arteriolar and venular pressure by the servo-null micropuncture method while changing the pulmonary blood flow in isolated perfused cat lungs. We divided the lung vasculature into three longitudinal segments: 1) arterial (pulmonary artery to 30- to 50-microns arteriole), 2) microvascular (between 30- to 50-microns arteriole and venule), and 3) venous (30- to 50-microns venule to left atrium). The vascular resistance was calculated by dividing the pressure gradient by the flow. The pressure gradient of the microvascular segment did not increase, whereas the pressure gradient of the arterial and venous segments increased simultaneously with flow rate. Total and microvascular resistance decreased with increase of flow rate. Resistances of the arterial and venous segments did not change with increase in flow. We conclude that the microvasculature plays a crucial role in preventing pulmonary hypertension with increases in flow by decreasing microvascular resistance.

Animals↗
PubMed1994

Uric acid degrading enzymes, urate oxidase and allantoinase, are associated with different subcellular organelles in frog liver and kidney.

On the basis of differential and density gradient centrifugation studies, the site of the uric acid degrading enzymes, urate oxidase and allantoinase, in amphibia was previously assigned to the hepatic peroxisomes. Using specific antibodies against frog urate oxidase and allantoinase, we have undertaken an immunocytochemical study of the localization of these two proteins in frog liver and kidney, and demonstrate that whereas urate oxidase is present in peroxisomes, allantoinase is localized in mitochondria. Urate oxidase and allantoinase were detected by immunoblot analysis in both frog liver and kidney. The subcellular localization of these two enzymes was ascertained by Protein A-gold immunocytochemical staining of Lowicryl K4M-embedded tissue. Peroxisomes in frog liver parenchymal cells and kidney proximal tubular epithelium contained a semi-dense subcrystalloid core, which was found to be the exclusive site of urate oxidase localization. Allantoinase was detected within mitochondria, but not in peroxisomes of hepatocytes or proximal tubular epithelium. No allantoinase was detected in the mitochondria of nonhepatic parenchymal cells in liver and of the cells lining the distal convoluted tubules of the kidney. These results demonstrate that, unlike rat kidney peroxisomes which lack urate oxidase, peroxisomes of frog kidney contain this enzyme. Contrary to previous assumptions, these studies also clearly establish that urate oxidase and allantoinase, the first two enzymes involved in uric acid degradation, are localized in different subcellular organelles in frog liver and kidney.

Amidohydrolases↗
PubMed1994

In vivo osmoregulation of Na/myo-inositol cotransporter mRNA in rat kidney medulla.

myo-Inositol, a major compatible osmolyte in renal medulla, is accumulated in kidney-derived epithelial cells cultured in hypertonic media via Na/myoinositol cotransporter (SMIT). The altered medium osmolality of Madin-Darby canine kidney cells leads to changes in the transcription of the SMIT gene and mRNA abundance. To investigate whether SMIT is regulated by tonicity in vivo, renal medullary myoinositol and SMIT mRNA was measured in rats in hydrated and dehydrated states. Rats were divided into two groups: (1) hydrated rats, free access to 3% sucrose water; (2) dehydrated rats, 3 days of water deprivation. Urine sodium, potassium, urea, and osmolality in dehydrated rats were significantly higher than in hydrated rats. Renal medullary sodium, urea, and myo-inositol in dehydrated rats were significantly higher than in hydrated rats. Northern analysis revealed that there was a message hybridized to SMIT cDNA in the cortex and outer and inner medulla of the kidney. Compared with hydrated rats, SMIT mRNA in dehydrated rats was 2.6-fold higher in the outer medulla and 2.5-fold higher in the inner medulla. These results indicate that there is osmoregulatory SMIT in the outer and inner medulla of the kidney and that myo-inositol accumulation in this region is probably due to the increased expression of the SMIT gene.

Animals↗
PubMed1994

The role of the autonomic nervous system in the thermic effects of protein and carbohydrates in rats.

To investigate the roles of the autonomic nervous system in the thermic effects of protein and carbohydrates in rats, we determined the urinary excretion of catecholamines and the resting oxygen consumption by means of HPLC-fluorometry and open-circuit respirometry, respectively. Protein administration significantly increased the urinary excretion of norepinephrine and epinephrine over those on water administration. The thermic effect of protein was 16.6% of the basal metabolic rate and was inhibited by phentolamine, prazosin, or atropine, but not by propranolol. These results suggest that the sympathetic nervous system via alpha 1-adrenoceptors and the parasympathetic nervous system are involved in the thermic effect of protein. The administration of carbohydrates such as glucose, sucrose, and fructose significantly enhanced the urinary excretion of norepinephrine, but only glucose administration increased the urinary excretion of epinephrine. The thermic effects of carbohydrates were 8-9% of the basal metabolic rate and were inhibited by propranolol, but not by phentolamine or atropine. These findings suggest that the sympathetic nervous system via beta-adrenoceptors, but not the parasympathetic nervous system, contributes to the thermic effect of carbohydrates. Thus, we conclude that the autonomic nervous system is involved in the thermic effects of protein and carbohydrates by different mechanisms.

Animals↗
PubMed1994

Tissue kallikrein in rat and mouse neurons.

1. The distribution of tissue kallikrein in the rat brain was investigated by an immunohistochemical technique using antiserum against rat urinary kallikrein. The kallikrein-immunoreactive cells were widespread and scattered in both the cerebral cortex and brain stem, and the immunoreactive substance appeared to be preferentially localized around the neuronal cell body and their processes. 2. Furthermore, in order to define whether brain kallikrein levels vary in the aging process, the hydrolyzing activity in the cerebrum L-prolyl-L-phenylalanyl-L-arginine-4-methyl-coumaryl-7-amide (Pro-Phe-Arg-MCA) was measured in young (7-week old) and old (36-week old) female senescence accelerated mice (SAM-P/8 and SAM-R/1). The brain kallikrein levels of 7- as well as 36-week old SAM-P/8 were found to be lower than those of 7-week old SAM-R/1 (a control strain). Also, the brain kallikrein level of 36-week old SAM-R/1 animals was markedly reduced when compared with the 7-week old mice, suggesting that the reduced amount of cerebral kallikrein reflects the aging of the brain.

Aging↗
PubMed1994

Insulin-like growth factor-I messenger RNA content in the oviduct of Japanese quail (Coturnix coturnix japonica): changes during growth and development or after estrogen administration.

Complementary DNA (cDNA) of insulin-like growth factor-I (IGF-I) of Japanese quail was cloned. The nucleotide sequence analysis of the cDNA showed that only seven bases differed from those of chicken IGF-I cDNA in the 440 bases of the cloned region. This difference in nucleotide sequence did not cause changes in the amino acid sequence. Using this cloned cDNA, the changes in IGF-I mRNA content in the tissues of female quail during growth and development were investigated. In the oviduct, IGF-I mRNA was high about 5 weeks after hatching, concomitant with the rapid increase in total DNA content in this tissue (and the increases in total RNA content and RNA/DNA ratio). It decreased after 6 weeks, in accordance with the appearance of ovalbumin mRNA. When immature quails (6-day-old) were injected with diethylstilbestrol (DES), induction of IGF-I mRNA was observed after 24 hr. A few days later, there was a strong induction of ovalbumin mRNA. These two inductions were dependent on the dose of DES. The sequential inductions of these two mRNAs were also noted when DES was re-administered to the immature quail to which it had been first administered and from which then withdrawn. The present results showed that IGF-I gene is expressed extensively during development of the oviduct, probably in accordance with the activity of DNA replication, because the highest IGF-I mRNA content was observed when the total DNA content of the tissues increased extensively. The results suggest that IGF-I in the oviduct of Japanese quail works in an autocrinal or paracrinal mode during the development of this tissue.

Amino Acid Sequence↗
PubMed1994

[Effect of pirenzepine on gastric mucosal blood flow in patients after cardiac surgery].

Effect of pirenzepine on gastric mucosal blood flow (GMBF) in adult patients after coronary artery bypass grafting and mitral and aortic valve replacement was evaluated by using endoscopic laser-Doppler velocimetry. Heart rate, blood pressure and cardiac output increased temporarily after intravenous administration of pirenzepine 20 mg. GMBF also increased with these hemodynamic changes. However, GMBF remained significantly higher even after the decrease of cardiac output. Therefore, the increase in GMBF, which might be due in part to increase in cardiac output, could be explained by pirenzepine's own effect on gastric mucosa. Since the GMBF is one of the most important gastric mucosal defensive factors, pirenzepine may be useful in preventing acute gastric mucosal lesions in patients with low cardiac output.

Aged↗
PubMed1994

[Evaluation of a new nitric oxide delivery system during mechanical ventilation].

A new nitric oxide delivery and continuous monitoring system is described. During mechanical ventilation, this new system connected with Siemens Servo 900C ventilator was shown to be able to provide a constant inspired NO concentration (10-100 ppm) using chemiluminescence technique for NO analysis. Gas was analysed at the mixing chamber in front of the ventilator inlet and inspiratory tube connected with the soda-lime carbon-dioxide absorber. Both NO concentrations showed a good correlation (r = 0.99). The actual NO concentration from the NO supply cylinder was 1154 ppm and NO2 concentration was 14 ppm. In mongrel dogs, after 20 minutes of NO inhalation (10-100 ppm), the blood methemoglobin level reached a peak value of 2.2% starting from the pre-inhalation level of 0%. To optimize the safety of the clinical application of NO, its concentration should be measured continuously with chemiluminescence technique.

Animals↗
PubMed1994

[Perioperative management of the patient with hypertrophic obstructive cardiomyopathy].

We experienced the perioperative management of a patient with hypertrophic obstructive cardiomyopathy, who underwent open heart surgery. We performed three kinds of overload examinations, which included overdrive test using the pacemaker, continuous dopamine infusion with overdrive test and continuous diltiazem infusion with overdrive test, before and after cardio-pulmonary bypass under observation of the cardiac performances with transesophageal echocardiogram. We gained some important and interesting informations about the cardiac reserve of the patient. We could perform adequate perioperative management for the patient, taking the results of overload examinations into consideration.

Aged↗
PubMed1994

[Clinical experience of extracorporeal life support with the use of centrifugal pump ECMO].

Many reports have documented the good results with the use of extracorporeal life support in severe respiratory and circulatory failure. In our institution, we have used the centrifugal pump (Bioconsol 540: Biomedicus Co. Ltd.) ECMO for extracorporeal life support, and obtained good results in three cases. We used V-V bypass ECMO in one case (idiopathic interstitial pneumonia) and V-A by-pass ECMO in other two cases (ARDS and meconium aspiration syndrome). Duration of total bypass in three cases were 34, 51 and 140 hours, respectively. Recent reports on the use of centrifugal pump have indicated that it can bring excellent results of circulatory assist for cardiogenic shock. Compared to the roller pump method, the use of centrifugal pump ECMO was very simple, and could serve as an effective method for providing improvement in a relatively short period.

Adult↗
PubMed1994

Liver function tests of recipients with hepatitis C virus infection after bone marrow transplantation.

We used the polymerase chain reaction (PCR) to determine the presence of hepatitis C virus (HCV)-RNA in serum samples obtained from 19 patients with leukaemia or severe aplastic anaemia and investigated the correlation between HCV status and the results of liver function tests after bone marrow transplantation. PCR analysis of serum samples obtained before transplant showed that 10 of 18 patients were HCV-RNA-positive; 5 of these patients had developed acute post-transfusion hepatitis 1-11 months before transplant. An additional patient was HCV-RNA-positive on post-transplant day 62. Eight HCV-RNA-positive patients had pre-transplant GPT levels above the upper limit of normal. In these patients the GPT decreased significantly from a median of 104 IU/l (54-822 IU/l) pre-transplant to 23 IU/l (15-56 IU/l) on post-transplant days 8-12. In 9 of 11 HCV-RNA-positive patients, the GPT increased transiently from days 40 to 50 and again increased after day 100. Two of these patients died from hepatic failure; the GPT levels normalised in 3 patients after day 300 but continued to fluctuate in 4 patients. In the remaining 2 HCV-RNA-positive patients, the GPT remained close to the normal range throughout the follow-up period. Three HCV-RNA-positive patients became HCV-RNA-negative after 1-3 years. In these patients, the GPT remained normal for > 3 years after day 300.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Repair of osteochondral defects with grafts of cultured chondrocytes. Comparison of allografts and isografts.

Isogeneic and allogeneic chondrocytes cultured in collagen gel were transplanted into osteochondral defects in knee joints of inbred strains of rats. At 12 weeks, all eight isografted defects had healed successfully, compared with only four of eight allografted defects (p < 0.05). At 26 and 52 weeks, all defects except one had healed successfully and there was no significant difference in the success rate between the isografted and allografted groups. Control defects that had been implanted with only collagen gel did not heal successfully.

Animals↗