Biomedical subjects

M Katagiri

Publications and source records attributed to M Katagiri.

At least 55 records · Page 3Linked to original sources

PubMed1998

Diaphragm function during sighs in awake dogs after laparotomy.

Pulmonary complications after upper abdominal surgery are usually ascribed to temporary postoperative impairment of diaphragm function, which may not originate from intrinsic, structural injury but from reflex inhibition of diaphragm contractility. Spontaneous breathing is interrupted periodically by sighs, even after upper abdominal surgery. If postoperative dysfunction of the diaphragm arises from a reflexic inhibition, then the sigh should temporarily override the inhibition and restore normal diaphragm function. We implanted sonomicrometer and electromyogram transducers chronically in six dogs by laparotomy, then directly measured length, shortening, and electromyogram activity of costal and crural diaphragm segments, parasternal intercostal, and transversus abdominis muscles an average of 8.7 (range, 1-16) d later during resting tidal breathing and sighs. In each animal we analyzed a sequence of breaths, including a sigh, when costal or crural diaphragm contractility was abnormal. With each sigh, the shape and amplitude of costal and crural diaphragm segmental shortening improved abruptly, from 0.9 and 1.4% of baseline length (% LBL) during resting breathing to 12.1 and 11.1% LBL, respectively, during sighs. The sighs were compared to CO2-stimulated breaths of equivalent tidal volume, which did not show either pattern or amplitude of shortening equivalent to sighs. We conclude that diaphragm dysfunction after laparotomy arises from a reflex inhibition, which is overridden abruptly to return diaphragm function briefly to normal during each spontaneous sigh.

Abdominal Muscles↗

PubMed1998

[The regulation of steroidogenesis by 17 alpha-hydroxylase/17,20-lyase (P450c17)].

Cytochrome P450c17 (P450c17) catalyzes 17 alpha-hydroxylation and 17, 20-lyase reactions. This enzyme plays a key role in determination of the balance between glucocorticoids and steroid sex hormones. In this review we discuss recent progress in the studies of both transcriptional regulation of CYP17 encoding P450c17 and enzymatic regulation of P450c17. Several transcription factors involved in cAMP-dependent transcription of the gene have been isolated and identified to be members of the atypical homeodomain "TALE" superfamily containing Pbx, Meis, Pknox and TGIF families. The studies of enzymatic regulation of P450c17 suggest that cytochrome b5 (b5), a heme protein, may switch the reaction of P450c17 by enhancing the 17, 20-lyase activity to increase the level of plasma C19 steroids. The importance of b5 in the synthesis of C19 steroids has also been shown in a clinical study reporting that the external genitalia was abnormal in a patient having a defect in b5. Therefore, this enhancement by b5 on the lyase activity of P450c17 may be essential to normal sexual differentiation in humans and also important in control of an optimal balance between sex steroid hormones and glucocorticoids. In addition, the age-dependent expression of P450c17 in immature rat livers is also discussed.

Adrenal Cortex↗

PubMed1998

[Effects of uvulopalatopharyngoplasty on patients with obstructive sleep apnea--the severity of preoperative tonsillar hypertrophy].

Predicting outcome following uvulopalatopharyngoplasty (UPPP) in obstructive sleep apnea is difficult. We hypothesized that UPPP is effective in obstructive sleep apnea patients with severe tonsillar hypertrophy. We examined the relationship between the severity of pre-operative tonsillar hypertrophy and the effect of UPPP in 38 patients with obstructive sleep apnea (oxygen desaturation index (ODI) > or = 20). The patients were classified into three groups according to the Mackenzie Classification of tonsillar hypertrophy. Ten patients were classified as grade 1 (M1) hypertrophy, i.e. tonsils just visible beyond the palatal arch. Five patients had grade 3 (M3) hypertrophy, i.e. tonsils appearing to contact each other at the midline. The remaining 23 patients had grade 2 (M2) hypertrophy, i.e. intermediate enlargement. We measured the apnea index, ODI, DST 90, and DST 85 (%time with SaO2 < or = 90% and < or = 85%, respectively) using a screening device for sleep apnea (Apnomonitor II, CHEST M. I. Co. Tokyo, Japan) before and after UPPP. Following UPPP, the mean ODI decreased significantly in all groups: 59 to 9/hr (p < 0.005) in the M3 group, 53 to 27/hr (p < 0.001) in the M2 group, and 48 to 33/hr (p < 0.05) in the M1 group. Post-UPPP ODI decreased by 83% in M3, 45% in M2, and 28% in M1 patients. Successful UPPP, defined by a post-UPPP ODI of less than 20/hr and a greater than 50% decrease in post-UPPP ODI, occurred in 80% of M3, 43% of M2, and 10% of M1 patients. We conclude that tonsillar hypertrophy can predict a successful response to UPPP in obstructive sleep apnea patients.

Adult↗

PubMed1998

[Requirement of class II and membrane proximal region of mouse mammary tumor virus superantigen (Mtv SAG) in Mtv7 SAG presentation].

Although in some cases superantigens (SAGs) have been shown to bind directly to T cell receptor (TCR) in the absence of MHC molecules, the precise role of MHC class II in SAG presentation to T cells is not thoroughly understood. In particular, it is still not known whether MHC class II is a mere transporter of mouse mammary tumor virus (Mtv) SAG to the cell surface or an essential component complexed with SAGs for TCR triggering. In this study, we found that MHC class II negative B cell line transfected with CD72/Mtv7 sag chimeric gene could express the Mtv7 SAG on the cell surface. The murine B cell line M12.4.1 and its MHC class II negative mutant, M12C3 are transfected with CD72/Mtv7 sag chimeric gene. Although both transfectants expressed Mtv7 SAG on their cell surface, M12.4.1 but not M12C3 activated Mtv7 SAG responding T cell hybridomas. The results argue that the mere presence of Mtv7 SAG on the cell surface does not effectively transmit the signal to TCR. As MHC class II-positive cells transfected with CD72/Mtv7 sag gene caused T cell activation, the cytoplasmic/transmembrane portion of Mtv7 SAG is not essential for T cell activation. In order to examine the importance of the membrane proximal region of Mtv7 SAG in T cell activation, we constructed chimeric genes between the encoding cytoplasmic/transmembrane portion of CD72 and N-truncated extracellular region of Mtv7 sag (CD72/ATG3, CD72/ATG5). Despite the expression of Mtv7 SAG on the cell surface, cells transfected with CD72/ATG3 or CD72/ATG5 genes were unable to stimulate Mtv7 SAG responding T cell hybridomas. The results indicate that 54 extracellular amino acids (the difference between CD72/Mtv 7 SAG and CD72/ATG3) located proximal to the membrane may be important for Mtv7 SAG function.

Animals↗

PubMed1998

Effects of rebamipide in combination with lansoprazole and amoxicillin on Helicobacter pylori-infected gastric ulcer patients.

The aim of this study was to compare the additive effect of rebamipide with that of teprenone in combination with dual therapy on H. pylori eradication. A total of 102 H. pylori-positive gastric ulcer patients were assigned at random to two groups; in addition to dual therapy (amoxicillin 500 mg thrice daily and lansoprazole 30 mg every morning for two weeks), one group received rebamipide 100 mg thrice daily for eight weeks, while the other group received teprenone 50 mg thrice daily for eight weeks. H. pylori diagnosis after treatment was made by [13C]UBT. The ulcer healing rate was 85.7% in the rebamipide group and 79.5% in the teprenone group (P = NS). The eradication rate was 68.4% (95% CI = 54-83%) in the rebamipide group and 47.7% (95% CI = 32-61%) in the teprenone group (P = 0.043) by per-protocol analysis. These findings suggest that the efficacy of dual therapy may be increased by the administration of rebamipide.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1998

Ten minute 13C-urea breath test for the diagnosis of Helicobacter pylori infection.

We investigated the utility of a 10-min 13C-urea breath test (13C-UBT) using 100mg of 13C-urea; this is a simple and rapid method for the detection of Helicobacter pylori infection. One hundred and fifty-one patients in whom the identification of H. pylori was established by rapid urease test, culture, and histology of six biopsy specimens underwent 254 13C-UBT examinations before and/or after eradication treatment. In the 133 patients who did not receive eradication treatment, the calculated sensitivity of the 10-min 13C-UBT was 99.4% and specificity 100% when the cut-off point was set at 3.5/1000, using a mass spectrometer. In the 121 patients who received eradication treatment, this cut-off point gave a sensitivity of 86.7%, a specificity of 99.1%, and a positive predictive value of 92.9%, with a negative predictive value of 98.1%. There were no significant differences between the diagnosis of H. pylori infection at 1 month and more than 3 months after the endpoint of eradication treatment. The 10-min 13C-UBT is suitable for the diagnosis of H. pylori infection before and after eradication treatment.

Breath Tests↗

PubMed1997

Epitope analysis of birch pollen allergen in Japanese subjects.

Birch pollen is a very common cause of nasal allergy (pollinosis) not only in Scandinavia, Europe, Canada, and the northern part of the United States but also in Hokkaido, Japan. We have previously reported a positive association between the HLA-DR9 phenotype and the development of birch pollen allergy in Japanese subjects. However, there is little information about T cell epitopes of birch pollen which are presented by HLA class II molecules other than HLA-DR9. Therefore, we analyzed the difference in T cell epitope usage in patients who had HLA-DR9 versus those who did not. Seven Japanese patients with birch pollinosis were studied. Some groups of peptides representing T cell epitopes (Betula verrucosa; Bet VI peptides, p7-33, p23-46, p138-160) appeared to be shared by the majority, while another peptide (Bet VI p72-95) was recognized predominantly by patients who expressed HLA-DR9 and/or HLA-DQ3 molecules. Moreover, seven T cell clones and eight T cell lines were generated from two patients who did not have HLA-DR9 or HLA-DQ3. Using some of these T cell clones/lines, we investigated the relationship between HLA class II molecules and antigenic peptides. One of these T cell clones recognized antigenic peptides in the context of the HLA-DQ1 molecule. To our knowledge, this is the first indication that the epitope on Bet VI can be presented by the HLA-DQ molecule.

Allergens↗

PubMed1997

Studies on gastric mucosal cell injury induced by Helicobacter pylori.

The cause of gastric cell injury induced by Helicobacter pylori was investigated in vitro using gastric mucosal cells derived from male Japanese white rabbits. To evaluate the contribution of the potent urease activity of H. pylori to gastric mucosal cell injury, the supernatant of the H. pylori bacterial pellet, solubilized with N-octyl-glucoside, was added to the gastric mucosal cell suspension. Cell injury was assessed by lactate dehydrogenase (LDH) release into the extracellular fluid. Treatment of cells with H. pylori extracts together with urea resulted in high levels of LDH release, suggesting definite gastric mucosal cell injury, and elevation of ammonia concentration was also observed. In contrast, incubation with H. pylori extracts alone or urea solution alone did not result in increased LDH release or elevated ammonia concentrations. The degree of LDH release from gastric mucosal cells due to H. pylori extracts in the presence of urea was similar to that induced by administration of the same amount of exogenous ammonia. The addition of acetohydroxamic acid, a potent specific urease inhibitor, remarkably inhibited ammonia production, the elevation of pH of extracellular fluid, and LDH release in a dose-dependent manner. These results suggest that ammonia produced by potent urease activity of H. pylori in the presence of urea plays an important role in the pathogenesis of gastric mucosal cell injury.

Ammonia↗

PubMed1997

Increased cytokine production by gastric mucosa in patients with Helicobacter pylori infection.

To determine the mechanisms of gastric mucosal injury associated with Helicobacter pylori infection, we investigated the contents of cytokines and inflammatory cell infiltration in the gastric mucosa. Ninety-six patients with dyspepsia were studied (58 gastric ulcer, 38 nonulcer dyspepsia). Of the 96 patients, 63 were infected with H. pylori as determined by microscopic examination with HE staining, culture of H. pylori, or the rapid urease test. Endoscopic biopsy specimens were obtained from both the antrum and the body to examine interleukin (IL)-8, IL-6, IL-1 beta, and tumor necrosis factor-alpha contents in the gastric mucosa by enzyme-linked immunosorbent assay. Inflammatory cell infiltration was assessed according to the Sydney system. IL-8 content was enhanced in both the antral and body mucosa of the H. pylori-positive patients compared with the H. pylori-negative patients. Furthermore, IL-8 content correlated well with the infiltration of both mononuclear cells and polymorphonuclear cells. These results suggest that IL-8 plays important roles in the pathogenesis of gastric mucosal injury associated with H. pylori infection.

Case-Control Studies↗

PubMed1997

Biological activity of purpurogallin.

Purpurogallin showed antibacterial activity toward gram-positive bacteria. Strong activity against methicillin-resistant Staphylococcus aureus [minimal inhibitory concentration (MIC) against methicillin of 1600 micrograms/ml] was found, with MIC of 11.0 micrograms/ml. Purpurogallin inhibited the growth of all tested plants and decreased the chlorophyll content in the cotyledons of Brassica campestris subsp. rapa. It showed potent inhibitory activity against prolyl endopeptidase (the 50% inhibitory concentration was 1.6 x 10(-5) M), unlike its analogues, hinokitiol and tropolone.

Anti-Bacterial Agents↗

PubMed1997

Durable remission after splenectomy for Waldenström's macroglobulinemia with massive splenomegaly in leukemic phase.

A patient with M-proteinemia (IgM, kappa type), lymphocytosis, anemia, and massive splenomegaly, was diagnosed as having Waldenström's macroglobulinemia (WM). Since this case was refractory to chemotherapy, splenic irradiation was performed, which effectively reduced the serum IgM level, spleen size, and lymphocyte counts; however, its effect was transient. Splenectomy was then carried out. The spleen contained abundant IgM-producing lymphocytes, and after splenectomy, the serum IgM values decreased and the peripheral blood counts returned to near normal. The transient increases of serum IgM occurred during two infectious episodes postoperatively. The patient has now been in a satisfactory remission for six years after splenectomy. The removal of an IgM-producing/secreting site and release from hypersplenism may be the major mechanisms involved in achieving the durable remission after splenectomy. In individual cases of WM with massive splenomegaly, we recommend splenectomy as part of the management of this disorder.

Humans↗

PubMed1997

[Analysis of T cell epitopes on birch pollen allergen].

Allergy to birch pollen is common in the Northern Europe, North America, and in Japan, mainly in Hokkaido Island. Previously, we have reported the positive association of birch pollen allergy in HLA-DR9 antigen. We also have identified the recognition sites in 17kDa protein (Bet v1), known as the major allergen of birch pollen, by using T cell proliferation assay against the trypsin digested materials of the 17kDa protein. In this study, overlapping synthetic peptides correspond to the Bet v1 sequences were used to investigate the specificity of T cell responses in two HLA-DR9 positive patients. Three of the epitopes, residues 35-52, 75-92, and 102-119, were recognized by T cells from both patients. These three epitopes include HLA-DR9 binding motifs. Then we established T cell clone specific to p75-92 residue. 78-89 peptide was the core sequence of the epitope for the T cell clone contained the anchor residues characteristic to HLA-DR9. Within the core sequence, five residues were identified as critical for recognition on the basis of inhibition of the T cell proliferative response against singly substituted analogue peptides.

Allergens↗

PubMed1996

Analysis of anchor residues in a naturally processed HLA-DR53 ligand.

The peptide motif of the HLA-DR53 (DRB4(*)0101) molecule, which is associated with autoimmune diseases including Vogt-Koyanagi-Harada's syndrome, was determined by peptide binding assay using human L plastin p581 - 595 peptide and its substituted analogues. L plastin p581 - 595 peptide is one of the naturally processed peptides bound to HLA-DR9/DR53 (DRB1(*)0901/DRB4(*)0101) molecules. The binding affinity of each peptide to the HLA-DR53 molecule was measured by fluorescence intensity of biotinylated peptides to L cell transfectants expressing HLA-DR53 molecules, followed by treatment with avidin-fluorescence. Binding of biotinylated peptides to HLA-DR53 molecules was not inhibited by all single-alanine-substituted nonbiotinylated peptides, indicating that the replaced position was important for binding to the HLA-DR53 moleule. The inhibitory motif is considered to be an HLA-DR53-specific binding motif, composed of a positively charged residue (K) at position 1, a hydrophobic residue (I) at position 4, positively charged residue (R or K) at position 8 or 9, and another hydrophobic residue (I) at position 10. This predicted motif is different from the binding motifs of other HLA-DR molecules.

Amino Acid Sequence↗

PubMed1996

Prediction of bone mass in renal hyperparathyroidism by newly developed bone metabolic markers: evaluation of serum levels of carboxy-terminal pyridinoline cross-linked telopeptide of type I collagen and carboxy-terminal propeptide of type I procollagen.

Serum levels of the carboxy-terminal pyridinoline cross-linked telopeptide of type I collagen (ICTP) and the carboxy-terminal propeptide of type I procollagen (PICP) were measured in 95 patients with renal hyperparathyroidism who had undergone a total parathyroidectomy and autotransplantation of a small portion of the resected gland. The results were compared with the serum levels of other bone metabolic markers and bone mineral densities in the distal radius (R-BMD) and lumbar vertebrae (L-BMD), which were measured by dual energy x-ray absorptiometry and converted to the percentage of the mean value of sex- and age-matched healthy controls. The preoperative mean values of ICTP and PICP were 142.4 ng/ml and 187.8 ng/ml, respectively. Although the serum levels of PICP levels exceeded the normal range in 42.1% of the patients, those of ICTP exceeded it in all of them. The serum levels of ICTP correlated positively not only with those of tartrate-resistant acid phosphatase (TRACP), total alkaline phosphatase (ALP), and osteocalcin but also negatively with the values of %R-BMD and %L-BMD and seemed to manifest specifically the disturbance of bone metabolism. On the other hand, the serum levels of PICP correlated with those of ALP and TRACP but not with values of %BMDs. After surgery, the serum levels of ICTP decreased gradually, but those of PICP increased immediately up to peak values at 7 days and then decreased gradually after 14 days, reaching the normal range at 3 months. These changes in the bone metabolic markers seemed to reflect the change in bone metabolism that was converting from bone resorption to bone formation. The percent change in the PICP/ICTP ratio at 7 days correlated significantly with the percent change in R-BMD at 12 months, and it was suggested that postoperative bone gain might be predicted using a combination of postoperative changes in PICP and ICTP.

Absorptiometry, Photon↗

PubMed1996

Effects of lansoprazole plus amoxycillin on the cure of Helicobacter pylori infection in Japanese peptic ulcer patients.

AIM: The effect of lansoprazole plus amoxycillin on curing Helicobacter pylori infection and peptic ulcer recurrence was evaluated. METHOD: The study group was composed of 68 patients with gastric ulcers and 51 with duodenal ulcers, all were H. pylori-positive. The participants were assigned at random to the lansoprazole alone group (lansoprazole 30 mg o.m. for 6 or 8 weeks) or the lansoprazole plus amoxycillin group (lansoprazole alone regimen plus amoxycillin at 500 mg q.d.s. concomitantly for the first 2 weeks). Healed patients were not given maintenance treatment with acid secretion inhibitors. The cure rate for H. pylori infection and the ulcer recurrence rate after 1 year were investigated. RESULT: The cure rate for H. pylori infection was 4.2% in patients receiving lansoprazole alone and 38.5% in patients receiving lansoprazole plus amoxycillin (P < 0.01) for gastric ulcers, and 0% in patients receiving lansoprazole alone and 61.9% in patients receiving lansoprazole plus amoxycillin (P < 0.001) for duodenal ulcers. The recurrence rate was 42.3% in patients receiving lansoprazole alone and 28.6% in patients receiving lansoprazole plus amoxycillin for gastric ulcers, and 66.7% for patients receiving lansoprazole alone and 11.1% for patients receiving lansoprazole plus amoxycillin (P < 0.001) for duodenal ulcers. None of the patients with gastric or duodenal ulcers cured of H. pylori infection had a recurrence. CONCLUSION: Concomitant use of lansoprazole and amoxycillin increased the curative effects on H. pylori infection. However, the cure rates with this regimen remained inadequate.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1996

Atrophic changes of gastric mucosa are caused by Helicobacter pylori infection rather than aging: studies in asymptomatic Japanese adults.

BACKGROUND: The current study was designed to evaluate the effect of aging and Helicobacter pylori infection on the gastric mucosa in asymptomatic Japanese adults. MATERIALS AND METHODS: Eighty-five asymptomatic healthy adults were recruited from a health-screening center in Sapporo. All subjects underwent endoscopy and gastric biopsy, and serum was obtained for IgG antibodies to H. pylori, serum gastrin, and pepsinogen levels. RESULTS: The prevalence of atrophic change of the gastric mucosa assessed by pathological findings increased with age (49% in the 30- to 39-year-old group compared to 89% in those 60 years and older, p < .001). The frequency of intestinal metaplasia also increased with age (38% in the 30- to 39-year-old group compared to 82% in those 60 years and older, p < .001). In contrast, the frequency of atrophic gastritis and intestinal metaplasia was extremely low in the H. pylori seronegative group regardless of age. Mean serum gastrin level in H. pylori-positive adults was significantly greater than in those who were H. pylori-negative (114.3 +/- 11.2 compared to 65.8 +/- 6.5 pg/ml, p < .03). The serum pepsinogen I-II ratio was significantly lower in those with H. pylori infection than in those without (3.1 compared to 6.6, p < .0001). CONCLUSIONS: These results suggest that the chronological changes in the gastric mucosa in Japanese individuals are either entirely related to H. pylori infection or the process is greatly accelerated by H. pylori infection.

Adult↗

PubMed1996

Localization of the human IL-2-inducible T-cell kinase gene (ITK) to chromosome band 5q34 and the mouse gene (Itk) to chromosome 15 by fluorescence in situ hybridization.

ITK, predominantly expressed on T cells and myeloid cells, is a member of the Tec nonreceptor tyrosine kinase family. Both human ITK and mouse Itk genomic clones were isolated to assign the chromosome location. The human ITK gene was mapped to chromosome band 5q34 and the mouse gene to chromosome 15 by fluorescence in situ hybridization.

Animals↗

PubMed1996

Myelofibrosis secondary to renal osteodystrophy.

A hemodialyzed women with secondary hyperparathyroidism who recovered well from myelofibrosis after a total parathyroidectomy with autotransplantation of parathyroid tissue to the forearm (PTx) is described. Before the operation, she had received regular transfusions to maintain an adequate hematocrit even under recombinant human erythropoietin (rhEpo) therapy. She showed splenomegaly and leukoerythroblastosis was present in her peripheral blood. A bone marrow biopsy and bone marrow scintigraphy confirmed the diagnosis of myelofibrosis. After PTx, her hematocrit gradually increased without any transfusion. It has been maintained around 35% now 16 months since the operation. Her spleen has also gradually decreased in size. In addition, no leukoerythroblastosis has been found in the peripheral blood. Serial follow-up scintigraphy of bone marrow revealed a decline in extramedullary hematopoiesis. These findings indicated that her myelofibrosis was the result of secondary hyperparathyroidism, and that this complication is potentially reversible if accurate treatment is given. Physicians dealing with the end-stage renal disease should be aware of this complication to avoid additional transfusions.

Alkaline Phosphatase↗