Proliferating sites of Rickettsia tsutsugamushi in mice by different routes of inoculation evidenced with immunofluorescence

The sites of multiplication of Rickettsia tsutsugamushi in mice by different routes of inoculation were investigated by means of immunofluorescence. R. tsutsugamushi (Kato, Karp, Gilliam and Miyake strains) inoculated by intraperitoneal route multiplied significantly in mesothelial and inflammatory cells of the peritoneal cavity of DDD and BALB/c (nu/nu) mice. The rickettsial growth was not detected in parenchymal cells of the liver, spleen, kidneys and lymph nodes of DDD mice, but slightly observed in those cells of the nude mice. When inoculated by subcutaneous route, the rickettsial antigens were detected in small amount in the peritoneal mesothelial and inflammatory cells, whereas a marked proliferation of R. tsutsugamushi was demonstrated in liver cells, Kupffer cells, and endothelial cells of the sinus of spleen and lymph nodes. A specific antibody to Karp strain, administered intraperitoneally, prevented effectively rickettsial growth in the peritoneal cavity of BALB/c (nu/nu) mice challenged intraperitoneally, 6 hours later, with Miyake strain (Karp type) and the animals were infected after a long-term incubation period showing the findings of rickettsial localization similar to that in subcutaneously inoculated animals. This fact suggests a partial involvement of humoral immunity in resistance of mice against R. tsutsugamushi infection. The potential importance of these findings in experimental infection with R. tsutsugamushi was discussed.     

Polypectomy of a large juvenile polyp in the ascending colon

A large juvenile polyp in the ascending colon of a 5-year-old boy was successfully polypectomized . The boy often had rectal bleeding, and anemia was known. Transection was necessary to prevent bleeding and anemia.     

Protective effect of N,N’‐dimethylthiourea against stress‐induced gastric mucosal lesions in rats

In the present study, we examined the protective effect of N,N’‐dimethylthiourea (DMTU), a scavenger of hydroxyl radical (), against water‐immersion restraint stress (WIRS)‐induced gastric mucosal lesions in rats. When male Wistar rats fasted for 24 h were exposed to WIRS for 3 h, gastric mucosal lesions occurred with increases in the levels of gastric mucosal myeloperoxidase (MPO), an index of tissue neutrophil infiltration, pro‐inflammatory cytokines (tumor necrosis factor alpha and interleukin 1beta), lipid peroxide (LPO), and nitrite/nitrate (NOx), an index of nitric oxide synthesis, and decreases in the levels of gastric mucosal nonprotein SH and vitamin C and gastric adherent mucus. DMTU (1, 2.5, or 5 mmol/kg) administered orally at 0.5 h before the onset of WIRS reduced the severity of gastric mucosal lesions with attenuation of the changes in the levels of gastric mucosal MPO, pro‐inflammatory cytokines, LPO, NOx, nonprotein SH, and vitamin C and gastric adherent mucus found at 3 h after the onset of WIRS in a dose‐dependent manner. Serum levels of corticosterone and glucose, which are indices of stress responses, increased in rats exposed to WIRS for 3 h, but DMTU pre‐administered at any dose had no effect on these increases. These results indicate that DMTU protects against WIRS‐induced gastric mucosal lesions in rats by exerting its antioxidant action including scavenging and its anti‐inflammatory action without affecting the stress response.     

Immune responses in mice infected with Schistosoma japonicum and treated with praziquantel in special reference to the role of egg antigen

The sequential change of class-specific antibodies to antigens of the Schistosoma japonicum egg and adult worm in mice after treatment with a single oral dose of praziquantel (PZQ) at 100 mg/kg was studied using ELISA in regard to the resulting release of egg antigen. In 3 out of 4 mice treated with PZQ, only IgM antibody to egg antigen was drastically declined from 30 min to 6 hr after treatment, and then gradually rose to the initial level after 2 to 3 days. After adding 100 micrograms/ml PZQ to the serum from infected mouse in vitro, no reduction of antibody activity was observed. In 2 infected mice intravenously injected with 1.5 mg of egg antigen only anti-egg IgM was remarkably reduced shortly after injection and fatal anaphylactic reactions occurred after 30 or 60 min. By the inhibition ELISA, the amount of circulating immune complex (CIC) in serum was shown to be correlated with increase in amount of egg antigen and with decrease in titers of anti-egg IgM. The results suggested that, after treatment with PZQ, miracidia within eggs in host tissues hatched and that there was increased release of egg antigen which was bound by IgM to produce CIC. This resulted in transiently lower levels of anti-egg IgM antibody. The antigen release may also cause anaphylactic reactions such as abdominal pain and vomiting reported in many post-treatment patients.     

ST segment and T wave alternans in a patient with Brugada syndrome

We describe a patient with Brugada syndrome in whom J point and ST-segment elevation in leads V1 and V2 were augmented by atrial pacing and intravenous administration of propranolol or cibenzoline. Significant T wave alternans with a 2:1 appearance of terminal negative T wave was observed in the absence and presence of atrial pacing after the administration of cibenzoline. The cellular mechanism responsible for T wave alternans, beat-to-beat appearance of terminal negative T wave and augmented J point and ST-segment elevation is discussed.     

Diagnosis of a case of ectopic parathyroid adenoma on the early image of 99mTc-MIBI scintigram

We report the case of a 64-year-old woman who had a severe hypercalcemia. Serum calcium, intact parathyroid hormone (PTH), 1alpha, 25 (OH)(2 )vitamin D(3) levels were all elevated, and serum phosphorus level was decreased, which were all consistent with primary hyperparathyroidism (PHPT). (201)Tl/(99m)Tc subtraction scintigraphy failed to detect any abnormal accumulation in the neck and chest, while (99m)Tc-MIBI scintigraphy demonstrated the focal accumulation of increased radiotracer uptake in the mediastinum only on the early image, but not on the delayed image. Neck and chest computerized tomography scanning showed a small nodule at the retrosternal region, and a selective venous sampling study of the intact PTH suggested PTH production from the nodule. Together with the observation of the early image of (99m)Tc-MIBI scintigraphy, it was diagnosed that the patient had an ectopic parathyroid adenoma. Video-assisted thoracic surgery was performed. A 15-mm diameter mass, visualized by an intravenous infusion of methylene blue, was excited. The histopathology was consistent with the parathyroid adenoma. The adenoma was composed of mainly chief cells and rarely oxyphil cells. The absence of oxyphil cells would explain the lack of (99m)Tc-MIBI retention on late-phase imaging in our case. Even without uptake on the delayed image of (99m)Tc-MIBI scintigram, the early image was available for the localization of an ectopic parathyroid adenoma.     

Influences of prolonged apnea and oxygen inhalation on pulmonary hemodynamics during breath holding: quantitative assessment by velocity-encoded MR imaging with SENSE technique

PURPOSE: The purpose of our study was to assess the influence of prolonged apnea and administration of oxygen on pulmonary hemodynamics during breath holding (BH) by using velocity-encoded MR imaging combined with the SENSE technique (velocity MRI). MATERIALS AND METHODS: Ten healthy male volunteers underwent velocity MRI during BH with and without O(2) inhalation. All velocity MRI data sets were obtained continuously with the 2D cine phase-contrast method during a single BH period. The data were then divided into three BH time phases as follows: first, second and third. To evaluate the influence of prolonged apnea on hemodynamics, stroke volume (SV) and maximal change in flow rate during ejection (MCFR) of second and third phases were statistically compared with those of first phase by using the ANOVA followed by Turkey's HSD multiple comparison test. To assess the influence of O(2) on hemodynamics, SV and MCFR with or without O(2) were compared by the paired t-test. To assess the measuring agreement of hemodynamic indices during prolonged breath holding, Bland-Altman's analysis was performed. RESULTS: Prolonged apnea had no significant influence on SV and MCFR regardless of administration of O(2) (p>0.05). Mean MCFR for all phases was significantly lower with administration of O(2) than without (p<0.05). The limits of agreement for MCFR with O(2) were smaller than without. CONCLUSION: O(2) inhalation modulated maximal change in flow rate during ejection, and did not influence stroke volume during breath holding. Influence of O(2) inhalation should be considered for MR measurements of pulmonary hemodynamics during breath holding.     

Identification of HLA-A*2402-restricted epitope peptide derived from ERas oncogene expressed in human scirrhous gastric cancer

ERas is a recently identified oncogene involved in the tumorgenic growth of embryonic stem cells. We examined the significance of ERas expression in scirrhous gastric carcinoma, and the possibility of ERas as a tumor-associated antigen of gastric cancer for developing a cancer vaccine. ERas expression was determined in scirrhous gastric carcinoma specimens by immunohistochemical staining. To assess the possibility of the ERas protein as an anticancer vaccine target, we examined whether ERas for HLA-A-restricted epitope peptides were capable of eliciting cytotoxic T lymphocyte activity. Immunohistochemical analysis identified ERas protein in the nucleus and cytoplasm of cancer cells, yet ERas was not expressed in normal gastric epithelium. By western blotting, lysates of the scirrhous gastric cancer cell lines, OCUM-8, OCUM-2MD3 and OCUM-2M were shown to contain a 25-kDa band of ERas protein. ERas mRNA was detected in these cell lines by RT-PCR. To investigate cytotoxicity, we successfully established cytotoxic T lymphocyte clones stimulated by HLA-A*2402-restricted ERas peptides (FALDDPSSL). These peptides have specific cytotoxicity against corresponding HLA-A*2402-positive target cells pulsed with the candidate peptide. We found that the cytotoxic T lymphocyte clones demonstrated cytotoxic activity against OCUM-8 cells that endogenously express ERas. Our results suggest that ERas is a novel tumor-associated antigen with the potential application to be a vaccine against scirrhous gastric cancer.