Rectal leiomyoma with fibromuscular obliteration mimicking adematous lesion.
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Biomedical subjects
Publications and source records attributed to H Nakase.
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It remains unclear whether lymphoma of the mucosa-associated lymphoid tissue (MALT) in the extragastric organs is related to Helicobacter pylori infection or not. This report describes three patients with rectal MALT lymphoma negative for H. pylori infection, all of whom showed disease regression after being treated with antibiotics. One patient had MALT lymphoma in both the descending colon and the rectum; the other two patients had rectal disease only. None of the patients had chronic gastritis which was detectable either endoscopically or histologically and H. pylori infection was completely ruled out by various methods, including a urease breath test. These patients received antibiotic therapy. In all the patients, regression of MALT lymphoma was observed endoscopically and histologically, and polymerase chain reaction revealed that a previously observed rearranged band of immunoglobulin heavy chain had also disappeared after antibiotic treatment. These cases therefore suggest involvement of micro-organisms other than H. pylori in the development of rectal MALT lymphoma.
The rectum as an effective site for induction of systemic and local immunity has received little attention. Rectal immunization with microspheres-containing ovalbumin (MS-OVA) was tested for its ability to elicit systemic and mucosal immune responses. Rectal immunization with MS-OVA enhanced both Th2 dominant OVA-specific IgG levels in the serum and OVA-specific IgA levels in fecal extracts more prominently than did oral immunization. Cytokine analysis of CD4(+) T cells indicated a predominant induction of Th2-type responses compared to Th1-type responses following rectal immunization compared to oral immunization. These results demonstrate that rectal immunization with microspheres could be an effective new vaccination method.
To elucidate the role of p53/p16(INK4a)/RB1 pathways in the tumorigenesis of primary central nervous system lymphomas (PCNSLs), we have analyzed p14(ARF), p16(INK4a), RB1, p21(Waf1), and p27(Kip1) status in a series of their 18 sporadic cases of diffuse large B-cell lymphoma, using methylation-specific PCR, differential PCR, and immunohistochemistry. Homozygous deletion or methylation of p14(ARF) was detected in 10 (56%) PCNSLs, and they were almost entirely deletions (except 1 case). A total of 11 (61%) PCNSLs demonstrated homozygous deletion (6 cases) or methylation (5 cases) of p16(INK4a). Six tumors showed both p14(ARF) and p16(INK4a) homozygous deletions. Hypermethylation of the RB1 and the p27(Kip1) promoter region was detected in 2 (11%) cases, whereas p21(Waf1) methylation was not detected in any. Immunohistochemistry revealed loss of p14(ARF) and p16(INK4a) expression in 10 (56%) samples, correlating with the gene status. Four cases showed independent negative immunoreactivity for pRB and p27(Kip1), and nearly one-half of cases (8 of 18; 44%) were characterized by lack of p21(Waf1) expression. These results indicate that inactivation of p14(ARF) and p16(INK4a) by either homozygous deletion or promoter hypermethylation represents an important molecular pathogenesis in PCNSLs. Hypermethylation of RB1, p21(Waf1), and p27(Kip1) appears to be of minor significance, these genes being independently methylated in PCNSLs.
We report a patient with Budd-Chiari syndrome (BCS) and extrahepatic portal obstruction (EHO) associated with congenital antithrombin (AT) III deficiency. A 35-year-old man was admitted to Nishi Kobe Medical Center for evaluation of abnormal intrahepatic veins. By various imaging modalities, BCS and EHO were diagnosed. Laboratory data revealed parallel decreases in activity and antigen concentration of AT III despite normal liver function. Taken together, the etiology of both BCS and EHO was considered to be thrombosis, associated with congenital AT III deficiency. Two years after beginning warfarin therapy, the patient has no symptoms and his liver function remains normal. Anticoagulant therapy is considered useful for preventing progression of the disease.
Recurrent intestinal ulcer is a frequent problem in the management of Behçet's disease. However, no standard therapy for intestinal Beheçt's disease has been established. We report two patients with intestinal Behçet disease and recurrent ileal ulcers who were treated successfuly with a lipid emulsion of dexamethasone. In one patient, the cecal ulcer did not relapse after the intravenous administration initiation of a lipid emulsion of dexamethasone once a week, despite the discontinuation of prednisolone. In the other patient, the cecal ulcer showed a healing tendency, and oral administration of prednisolone was reduced from 40 to 15 mg/day after intravenous administration of a lipid emulsion of dexamethasone. Both patients experienced no complications associated with the administration of the emulsion. These results suggest that an intravenous drug delivery system using a lipid emulsion of dexamethasone is useful for treatment of intestinal Behçet's disease.
BACKGROUND & AIMS: Interleukin (IL)-7 is a critical cytokine in the development of T and B cells and is involved in gastrointestinal pathophysiology. The aim of this study was to investigate the involvement of IL-7 receptor (IL-7R) signaling in Helicobacter-induced gastritis. METHODS: C57BL/6 mice (n = 40) were inoculated with H. felis. Twenty mice were injected intraperitoneally with neutralizing IL-7R antibody (A7R34) every seventh day for 3 months. Histology, serum anti-H. felis antibody, and gene expression of IL-7, IL-7R, and proinflammatory cytokines in the gastric mucosa were evaluated. RESULTS: Seventeen of 20 (85%) infected mice without A7R34 developed severe atrophic gastritis, whereas there was no gastritis in A7R34-treated infected mice. There was no difference in the serum levels of anti-H. felis antibody between the 2 groups. IL-7, IL-7R, IL-1alpha, tumor necrosis factor alpha, and interferon gamma messenger RNA expressions were up-regulated in control infected mice, whereas only IL-7 messenger RNA was up-regulated in A7R34-treated infected mice. Immunohistochemistry indicated positive cytoplasmic staining of IL-7 in the gastric epithelial cells. CONCLUSIONS: These data suggest a critical role for IL-7 receptor signaling in the development of Helicobacter-induced gastritis in mice.
A 39-year-old man with acute myeloid leukemia underwent completely matched related hematopoietic stem cell transplantation. On post-transplantation day 83 he was diagnosed as having upper gastrointestinal graft-versus-host disease (GVHD) by endoscopic examination and pathological examination of endoscopic biopsy specimens, and daily administration of 60 mg of water-soluble prednisolone and 50 mg of cyclosporine was started. After steroid therapy, the symptoms of upper gastrointestinal GVHD disappeared completely and endoscopic findings dramatically improved.
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OBJECTIVE: The application of a laser scanning technique to measure regional cerebral blood flow (CBF) and tissue hemoglobin oxygenation (HbO2) using the rat closed cranial window preparation is described. METHODS: Twenty-nine male Wistar rats were used to consecutively measure local CBF by laser Doppler flowmetry and tissue HbO2 by a microspectrophotometric method at multiple corresponding cortical locations. The scanning technique used a computer-controlled micromanipulator. Data from three experimental models are presented: the whisker stimulation model, the ischemia-reperfusion model, and the sinus-vein thrombosis model. Sequential changes in local CBF and HbO2 data before, during, and after stimulation, ischemia, and sinus thrombosis were examined. Data from predefined locations within the same region were correlated with the topographical location and then arranged in a three-dimensional image. RESULTS: In the whisker stimulation model, we found a disproportionate increase in CBF (32 +/- 12%) as compared with that of HbO2 (9 +/- 4%) during stimulation. In the ischemia-reperfusion model, the three-dimensional image showed heterogeneous low CBF (depending on the area) and homogeneous HbO2 at a reduced level during ischemia and postischemic hyperperfusion. However, the range of oxygenation was normal after reperfusion. In the sinus-vein thrombosis model, drainage of the unsaturated blood via the collateral pathways was noted. CONCLUSION: The laser scanning technique is useful for visualizing sequential changes in hemodynamic-metabolic interactions of cortical brain tissue. This technique can reveal phenomena not detected by traditional monitoring procedures.
Immunological interaction between the host and Helicobacter pylori seems to play a critical role in follicular formation in gastric mucosa. We reported H. pylori-induced follicular gastritis model using neonatally thymectomized mice. In this study, we investigated the involvement of various cytokines in this model. BALB/c mice were thymectomized on the third day after birth (nTx). At 6 weeks old, these mice were orally infected with H. pylori. Histological studies showed that follicular formation occurred from 8 weeks after the infection and that most of the infiltrating lymphocytes were CD4(+) and B cells. Neutrophils increased transiently at 1 week after the infection. Gamma interferon, interleukin-7 (IL-7), and IL-7 receptor were expressed in the stomach of the nTx mice irrespective of the infection. In contrast, expressions of the tumor necrosis factor alpha, IL-4 and lymphotoxin-alpha genes were remarkably upregulated by the infection. Our findings suggest that follicular formation may require cooperative involvement of a Th2-type immune response, tumor necrosis factor alpha and lymphotoxin-alpha in addition to the Th1-type immune response in H. pylori-induced gastritis in nTx mice.
There are no staining methods that can reliably and unequivocally detect final infarcts in the acute stage of experimental ischemia. In most instances, 2,3,5-triphenyltetrazolium chloride (TTC) and hematoxylin and eosin (HE) stainings are accepted for this purpose, but neither is perfect. We performed a comparative study of the TTC immersion method and HE staining for quantification of early brain ischemic injury in cats, focussing on the reproducibility associated with planimetry. Focal brain ischemia was produced by middle cerebral artery (MCA) occlusion via the transorbital approach in 14 cats. After 6 h of occlusion, two slices of 3 mm thickness, passing through the optic chiasma and mammillary body, were selected for pathological examination. TTC immersion and HE staining were both used for planimetric study of the surface of the same slice. The area of the injury was traced manually with the aid of computerized digital planimetry and expressed as a percentage of the area of the contralateral hemisphere. The area of hemispheric injury and the area of gray matter injury were separately calculated in the TTC specimens, and each was compared with the area of gray matter injury in the HE-stained specimens. Measurements were repeated twice on each slice to estimate errors associated with manual tracing of the boundary of the area of injury. The mean percentage values of the area of injury in the TTC-immersed gray matter specimens were lower than those detected by HE staining, although there was a very significant correlation between the two. The differences between each two measurements of TTC-determined gray matter injury were significantly less than those between each two measurements of HE-determined gray matter injury. The differences between each two measurements of TTC-determined hemispheric injury were slightly less than those between each two measurements of TTC-determined gray matter injury, although there was no significant difference between them. For quantifying ischemic injury after 6 h of MCA occlusion in cats, the TTC immersion method is more reproducible and simpler in manner than HE staining, but the results of both are significantly correlated.
It is recognized that surgical obliteration of the cerebral veins by additional brain compression using retractors is dangerous. However, there is a lack of satisfactory management of this problem. We investigated whether intermittent brain compression can reduce brain injury from cerebral venous circulation disturbances (CVCDs). In Wistar rats (n = 25), a solitary cortical vein was occluded photochemically. The brain surface was compressed by a spring balance and constant compression at 30 mmHg was carried out for 60 min. Intermittent procedure compression protocols included four 15 min compressions at 5 min intervals, intermittent isometric exposure (IM), and intermittent isotonic exposure (IT). Local cerebral blood flow (ICBF) in the compressed area was measured together by laser-Doppler (LD) with the degree of brain compression. After 24 h, the brains were examined histologically. The animals were divided into the following five groups (each n = 5): 1, a sham operated control; 2, cortical vein occlusion (VO); 3, VO + continuous brain compression (CC); 4, VO + IM; and 5, VO + IT. The ICBF decreased significantly during the compression; however, recovery after the series of compressions was observed only in the VO + IM group, not in the VO + CC and the VO + IT groups (p < 0.05). The depth of the brain surface increased stepwise in the VO + IT group compared with the VO + IM group (p < 0.01). The resulting tissue damage was significantly larger in the VO + CC and VO + IT groups than in the vein occlusion group (p < 0.05), but not in the VO + IM group. The results of the present study suggest that intermittent isometric exposure under CVCDs could decrease brain retraction injury during neurosurgical operations and be more beneficial than continuous compression, providing that the compression pressure declines as the process advances.
The aim of the present study was to investigate whether immediate ischemia is more harmful to the brain than progressive ischemia. To do so, we examined the correlation between the degree and the process of ischemia using hypobaric hypotension technique, which was used to reduce systemic blood pressure acutely or progressively below the lower threshold of CBF regulation, in rat brain. In Wistar rats (n = 21), global ischemia using bilateral carotid arteries occlusion coupled with hypobaric hypotension was induced by lowering mean arterial blood pressure (MABP) progressively to 55, 45 and 35 mmHg or immediately to 35 mm Hg. Local cerebral blood flow (ICBF) by laser Doppler (LD) flowmetry and tissue hemoglobin oxygen saturation (HbSO2) by a microspectrophotometric method were measured at 25 corresponding locations using a 'scanning' technique which employs a computer-controlled micromanipulator. Regional CBF (rCBF) and rHbSO2 were determined by calculation of the median value from the 25 ICBF and IHbSO2 data. In the 'progressive' group, rCBF and rHbSO2 decreased gradually and reached 12.2 +/- 15.8 LD-units and 44.9% +/- 13.4% at 35 mm Hg of MABP, respectively. In the 'immediate' group, both parameters dropped suddenly to 7.86 +/- 10.6 LD-units (p < 0.01 vs. CBF of the progressive group) and 22.5% +/- 15.5% (p < 0.001 vs. tissue HbSO2 of the progressive group) from the control at 35 mmHg. These data suggested that cerebral ischemia is better tolerated if it is induced gradually. CBF recorded by LD-scanning technique and HbSO2 value by microspectrophotometric method correlated well in the ischemic condition, indicating that HbSO2 can be preserved if CBF is decreased gradually.
To clarify the substrate-recognition mechanism of carboxypeptidase Y, Fmoc-(Glu)n Ala-OH (n = 1 to 6), Fmoc-(Glu)n Ala-NH2 (1 to 5), and Fmoc-Lys(Glu)3Ala-NH2 were synthesized, and kinetic parameters for these substrates were measured. Km for Fmoc-peptides significantly decreased as peptide length increased from n = 1 to n = 5 with only slight changes in kcat. Km for Fmoc-(Glu)(5,6)Ala-OH were almost the same as one for protein substrates described previously (Nakase et al., Bull. Chem. Soc. Jpn., 73, 2587-2590). These results show that the enzyme has six subsites (S1' and S1-S5). Each subsite affinity calculated from the Km revealed subsite properties, and from the differences of subsite affinity between pH 6.5 and 5.0, the residues in each subsite were predicted. For Fmoc-peptide amide substrates, the priorities of amidase and carboxamide peptidase activities were dependent on the substrate. It is likely that the interactions between side chains of peptide and subsites compensate for the lack of P1'-S1' interaction, so the amidase activity prevailed for Fmoc-(Glu)(3,5)Ala-NH2. These results suggest that these subsites contribute extensively to substrate recognition rather than a hydrogen bond network.
Recently, long-term cerebrovascular adaptations after unilateral carotid ligation that increase the tolerance of the brain to subsequent episode of ischemia was reported(J Cereb Blood Flow Metab, 1998). However, the pathophysiological mechanisms underlying the phenomenon was unknown. We examined regional cerebral blood flow(rCBF) before, during and after subsequent ischemia in the development of the adaptation. Male Wistar rats(n = 18) were used. Unilateral(right) carotid artery ligation was performed 3 hours(group A: n = 8), 3 days(group B: n = 10) before forebrain ischemia. With bilateral carotid arteries occlusion, mean arterial blood pressure(MABP) was reduced by hypobaric hypotension down to 50 mmHg and maintained constant for 30 min. After hypotension, the experiment continued for 90 min. Local CBF were registered at 25(5 x 5) identical locations by laser Doppler scanning in the cortex during the experiment in bilateral hemispheres(at control phase, after the left carotid artery ligation, during ischemia and after hypotension). The physiological variable such as blood pressure and gas analysis were within normal range in all groups. There were no differences of rCBF between the right and left hemispheres in group A during the experiment. In group A, rCBF of both hemispheres significantly decreased after the ligation of the left carotid artery, during the induced ischemia (P < 0.05), and recovered to the value of before ischemia. Whereas, in group B rCBF of the left side(non-occluded side) decreased after the ligation of the left carotid artery, during the induced ischemia(P < 0.05), and recovered to the value of before ischemia, but rCBF of the right side(occluded side) decreased only during the induced ischemia(P < 0.05) and rCBF of the right side was significantly higher than the left brain after ligation of the carotid artery, during ischemia and after hypotension(P < 0.05). On the basis of these data, we concluded that cerebrovascular adaptations can be acquired by 3 days after unilateral carotid artery occlusion and the tolerance phenomenon is certainly attributed to microcirculatory improvement.
Ischemic/hypoxic tolerance induced by a subtoxic dose of neurotoxin, 3-nitropropionic acid(3-NPA), was recently reported as "chemical preconditioning". We previously showed that the neuroprotective effect by chemical preconditioning with 3-NPA was induced by prolonging the delay to hypoxic depolarization (HD) via activating adenosine receptors. In this study, we electrophysiologically assessed whether the protective effect of chemical preconditioning was potent after the onset of HD. An in vitro hippocampal slice model from adult gerbils was used to study the delay to HD during hypoxia and the recovery of synaptic responses after hypoxia. Hypoxia was sustained until a fixed period(8 min) following HD. These responses were examined in control slices and slices pretreated with subtoxic dose of 3-NPA(4 mg/kg) intraperitoneally at 3 hours prior to slice preparation. The delay to hypoxic depolarization in 3-NPA treated slices was significantly prolonged(p < 0.05). The field excitatory postsynaptic potential recovery after a fixed period of hypoxia under HD was also significantly improved in the 3-NPA treated group(48.6 +/- 23.8%) compared with the control group(29.2 +/- 12.2%) (p < 0.05). This finding indicates that chemical preconditioning with 3-NPA induces the neuroprotective effect against hypoxic damage after as well as before the onset of HD to the hippocampus.
Control of immune-regulating cells in the colonic mucosa is important in the treatment of patients with inflammatory bowel disease (IBD). The aim of study was to examine the therapeutic effect of dexamethasone (DX) microspheres on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats, a model for human Crohn's disease. DX microspheres and DX alone were administered orally to rats with TNBS-induced colitis. The macroscopic score, histological score, myeloperoxidase (MPO) activity, nitric oxide (NO) production, and gene expressions of proinflammatory cytokines, cyclooxygenase (COX)-1, and COX-2 in the colonic tissue were determined. Proliferating cell nuclear antigen (PCNA) staining and expression of nuclear transcription factor (NF)-kappaB in colonic tissues were also investigated. Macroscopic score, histological score, MPO activity, and NO production in rats treated with DX microspheres were significantly lower than in those treated with DX alone. The gene expression of proinflammatory cytokines and COX-2 in rats treated with DX microspheres was down-regulated, compared with that in rats treated with DX alone. The number of PCNA-positive cells in the DX microsphere group was larger than in the group treated with DX alone. DX microspheres suppressed NF-kappaB activation in TNBS-induced colitis more strongly than DX alone. Oral administration of DX microspheres appears to ameliorate mucosal injury in TNBS-induced colitis. This drug delivery system could be an ideal therapy for human IBD.