Toxicogenomic investigation on rat testicular toxicity elicited by 1,3-dinitrobenzene

Rats were treated with a single oral dose of 10, 25 and 50mg/kg of 1,3-dinitrobenzene (DNB), and the testis was subjected to a GeneChip microarray analysis. A total of 186 and 304 gene probe sets were up- and down-regulated, respectively, by the DNB treatment, where spermatocyte death and Sertoli cell vacuolation in testis and increased debris of spermatogenic cell in epididymis were noted. The expression profile for four sets of genes were investigated, whose expressions are reported to localize in specific cell types in the seminiferous epithelium, namely Sertoli cells, spermatogonia plus early spermtocytes, pachytene spermatocytes and round spermatids. The data demonstrated that pachytene spermatocyte-specific genes elicited explicit down-regulation in parallel with the progression of spermatocyte death, while other gene sets did not show characteristic expression changes. In addition, Gene Ontology analysis indicated that genes associated with cell adhesion-related genes were significantly enriched in the up-regulated genes following DNB treatment. Cell adhesion-related genes, namely Cdh2, Ctnna1, Vcl, Zyx, Itgb1, Testin, Lamc3, Pvrl2 and Gsn, showed an increase in microarray and the up-regulation of Cdh2 and Testin were confirmed by real time RT-PCR. The gene expression changes of pachytene spermatocyte-specific genes and cell adhesion-related genes were thought to reflect a decrease in the number of spermatocytes and dysfunction of Sertoli-germ cells adhesion junction, and therefore these genes would be potential genomic biomarkers for assessing DNB-type testicular toxicity.     

Molecular signaling mediated by angiotensin II type 1A receptor blockade leading to attenuation of renal dysfunction-associated heart failure

BackgroundIn patients with end-stage renal disease, angiotensin II type 1A receptor (AT1) blockade attenuates the associated cardiac dysfunction. We investigated the molecular signaling mediating that effect.Methods and ResultsWe used 5/6 nephrectomy to induce significant renal dysfunction in AT1 knockout (AT1KO) and wild-type mice (WT). Twelve weeks after nephrectomy, WT showed significant left ventricular dilation and dysfunction that were accompanied by cardiomyocyte hypertrophy, fibrosis, and reduced capillary density. All of these effects were significantly mitigated in AT1KO. Nephrectomy led to upregulation of myocardial expression of AT1, transforming growth factor-β1 (TGF-β1), matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1), and phosphorylated Akt (p-Akt), and also led to increased oxidative damage in cardiomyocytes. In AT1KO, TGF-β1, TIMP-1, oxidative damage levels were lower, whereas MMPs and p-Akt levels were higher. Treating nephrectomized WT mice with valsartan (an AT1 blocker), but not hydralazine, improved cardiac function and altered molecular signaling in a manner similar to that seen in AT1KO mice. Notably, AT1 expression was downregulated in valsartan-treated but not hydralazine-treated hearts.ConclusionsThese findings provide novel insight into the mechanism underlying the beneficial effects of AT1 blockade on cardiac function in a model of renal dysfunction–associated heart failure.     

Diabetic mastopathy of bilateral breasts in an elderly Japanese woman with type 2 diabetes: a case report and a review of the literature in Japan

We report a case of diabetic mastopathy in an elderly woman with type 2 diabetes. The patient was a 69-year-old woman diagnosed with type 2 diabetes at the age of 33 years. She had been treated with insulin for 25 years, however, her blood glucose had been poorly controlled. She noticed bilateral breast lumps in September 2002. Mammography of the breast showed increased density in the glandular pattern and architectural distortion without focal mass and microcalcification. Ultrasonography of the breast showed an irregular-shaped hypoechoic mass with an acoustic shadow. As malignancy needed to be excluded, core needle biopsy was performed in the left breast and diabetic mastopathy was confirmed pathologically. Diabetic mastopathy is usually a complication of pre-menopausal type 1 diabetes and develops in a unilateral breast. This case developed in bilateral breasts in an elderly type 2 diabetic patient.     

Creation and characterization of Japanese standards for myocardial perfusion SPECT: database from the Japanese Society of Nuclear Medicine Working Group

Objective Standards for myocardial single-photon emission computed tomography (SPECT) adapted for a Japanese population were not available. The purpose of this study was to create standard files approved by the Japanese Society of Nuclear Medicine and to make known the characteristics of the myocardial perfusion pattern of this population. Methods With the collaboration of nine hospitals, a total of 326 sets of exercise–rest myocardial perfusion images were accumulated from subjects with a low likelihood of cardiac diseases. The normal database included a ^99mTc-MIBI/tetrofosmin myocardial perfusion study with 360° (n = 80) and 180° (n = 56) rotations, ²⁰¹Tl study with 360° (n = 115) and 180° rotations (n = 54) and a dual-isotope study with 360° rotation (n = 27). The projection images were transferred by digital imaging and communications in medicine (DICOM) format and reconstructed and analyzed with polar maps. Results The projection data from multiple centers were successfully transferred to a common format for SPECT reconstruction. When the average values were analyzed using a 17-segment model, myocardial counts in the septal segment differed significantly between 180° and 360° rotation acquisitions. Regional differences were observed between men and women in the inferior and anterior regions. A tracer difference between ^99mTc and ²⁰¹Tl was also observed in some segments. The attenuation patterns differed significantly between subjects from the United States and those from Japan. Conclusions Myocardial perfusion data that were specific for the Japanese population were generated. The normal database can serve a standard for nuclear cardiology work conducted in Japan. All author are members of the JSNM Working Group of Standardization of Myocardial SPECT in a Japanese Population.     

Imaging analysis of the brain in a primate model of cerebral malaria

This paper reviews our studies concerning imaging analysis of the brain in a primate model of cerebral malaria. To elucidate the clinical features of cerebral malaria, we performed positron emission tomography with ¹⁸F-fluorodeoxyglucose (FDG-PET) scanning and magnetic resonance imaging (MRI) of the brain in Japanese macaques (Macaca fuscata) infected with Plasmodium coatneyi, a primate model of severe human malaria with cerebral involvement. On FDG-PET scanning, we observed diffuse and heterogeneous reduction of metabolism in the cerebral cortex in the acute phase of malaria infection. Although the monkey exhibited severe clinical signs, MR imaging did not reveal any significant changes during the course of infection. Histopathologic examination frequently revealed preferential sequestration of PRBCs in the cerebral and cerebellum capillaries, but neither parenchymal injury nor neuronal necrosis was found in the tissues. These results suggest that heterogeneous metabolic reduction and lack of abnormalities on MRI in the acute phase of CM may be due to any avoidance mechanisms from ischemia caused by sequestration. This may be one reason why more than half of CM patients have no neurological sequelae following recovery.     

Paragonimiasis in Cameroon: molecular identification, serodiagnosis and clinical manifestations

Paragonimiasis is a common parasitic zoonosis in Cameroon and neighbouring countries in Western Africa. Serum, sputum and faecal samples were collected in an endemic area of South West Province, Cameroon, after administration of a questionnaire to identify individuals with appropriate symptoms and histories. Microscopic examination revealed eggs in sputum from 16 people, but none in any faecal sample. These 16 were among the 25 and 26 people, respectively, positive by ELISA and by immunoblot using Paragonimus africanus crude antigens. Copro-DNA detection was attempted using 23 faecal samples (18 from sputum egg-negative and five from sputum egg-positive individuals). Copro-DNA was detected in four of the five sputum egg-positive individuals. These results strongly suggest that: (1) serology is much more sensitive than sputum examination for diagnosis of paragonimiasis; and (2) a copro-DNA test may be more sensitive than a microscopic search for eggs in faeces. Molecular sequence data from ITS2 and cox1 genes confirmed that adult worms experimentally raised in cats were P. africanus and that eggs from sputum or other worm products from human faeces also belonged to this species. Based on these results, 26 of 168 persons (15.5%) were diagnosed as suffering from paragonimiasis.     

Influence of Kupffer cell inactivation on cycloheximide-induced hepatic injury

In our previous study, we found that cycloheximide (CHX) induces hepatocellular necrosis as well as hepatocellular apoptosis. This article evaluates the role of Kupffer cells on cycloheximide-induced hepatic injury using gadolinium chloride (GdCl(3)) for the inhibition of Kupffer cells. One group of rats was treated with CHX (CHX group), and another was treated with GdCl(3) before being treated with the same dose of CHX (GdCl(3)/CHX group). The necrotic change in the GdCl(3)/CHX group was exacerbated under the induction of hepatocellular apoptosis by the CHX treatment. A substantial diminution of the number of ED1- or ED2-positive cells was demonstrated in the GdCl(3)/CHX group compared to the CHX group. In addition, the degree of decrease in ED2-positive cells was more apparent than that in ED1-positive cells. Increases in the mRNA levels of IL-10 and Stat3 were observed in the CHX group, but not in the GdCl(3)/CHX group. On the other hand, the hepatic mRNA levels of chemokines and adhesion molecules such as Ccl20, LOX-1, and E-selectin were significantly increased only in the GdCl(3)/CHX group. Thus, Kupffer cell inactivation by the GdCl(3) treatment leads to a loss of the capacity to produce IL-10, supposedly resulting in the enhancement of pro-inflammatory cytokine activities such as tumor necrosis factor (TNF) signaling. These events are suggested to be a factor of the inflammatory exacerbation in the livers of the GdCl(3)/CHX group. In conclusion, Kupffer cells may play a role in protecting hepatic necroinflammatory changes by releasing anti-inflammatory cytokines following the hepatocellular apoptosis resulting from CHX treatment.     

Angiotensin I Converting Enzyme Gene Polymorphism and Exercise Trainability in Elderly Women: An Electrocardiological Approach

Angiotensin I converting enzyme (ACE) gene Insertion / Deletion (I/D) polymorphism is associated with exercise trainability and exercise induced left ventricular hypertrophy. However, it is unclear whether this polymorphism influences exercise trainability in the elderly, and the electrocardiological alterations by exercise training is unknown among the genotypes. We herein investigated the association between ACE gene insertion/deletion (I/D) polymorphism, exercise trainability and the electrocardiological alternations by exercise in elderly women. Eighty four elderly women participated in this study. In all subjects the leg extension power (LEP) and lactate threshold (LT) were determined in order to evaluate the muscle strength, aerobic capacity and to also select the appropriate training intensity for each individual. They performed bench step exercise training for 12 weeks. A resting electrocardiogram was recorded for the obtained QTc interval in before and after the program. The baseline of aerobic capacity was higher in I/I than that in I/D, and the QTc interval was shorter in I/I than that in I/D. All other characteristics were similar among the genotypes. The QTc interval tended to be shorten only in the D/D. Furthermore, the value of the QTc interval change showed a significant difference between the I/I and D/D genotype after the program. The LT and LEP demonstrated a similar response among the genotypes. The D allele of ACE gene I/D polymorphism may therefore play a role in the electrocardiological aspect during exercise training, however, it was not found to influence the aerobic capacity.

Key points

• The D allele of ACE gene I/D polymorphism may play a role in the electrocardiological aspects during exercise training
• ACE gene I/D polymorphism was not determined the aerobic capacity and leg strength in elderly people.
• The ACE gene I/D polymorphism did not influence aerobic and strength trainability in elderly people.

Key Words: Electrophysiology, exercise, genes     

Identification of a constitutively active mutant of JAK3 by retroviral expression screening

To identify transforming genes in acute myeloid leukemia (AML) we here constructed a retroviral cDNA expression library from an AML patient, and then used this library to infect a mouse cell line 32Dcl3-mCAT. cDNA inserts of the cell clones which proliferated in the presence of granulocyte colony-stimulating factor were derived from JAK3 encoding a JAK3 mutant with a valine-to-alanine substitution at codon 674 and two additional amino acid substitutions. The transforming activity of JAK3(V674A) was confirmed by its introduction into 32Dcl3-mCAT. Sequencing of the original JAK3 cDNA derived from the patient, however, failed to detect the V674A mutation.