Human herpesvirus 6A infects human embryonic fibroblasts and induces G2/M arrest and cell death

Human herpesvirus 6 (HHV-6) is a beta-herpesvirus capable of infecting cells from different origin. In this study, infection with HHV-6A of human embryonic fibroblasts (HEFs) was performed. Infected cells showed obvious cytopathic effects (CPE). PCR and immunohistochemical tests also confirmed that HEFs are susceptible to HHV-6A infection. The biological effects of HHV-6A infection on HEFs were studied. Infected cells showed decreased proliferation as measured by [(3)H] thymidine incorporation and cell counting. Further analysis demonstrated that infection with HHV-6A leads to cell cycle arrest at G2/M phase and increasing cell death. This is the first demonstration that infection of HEFs with HHV-6A causes profound alterations of cell properties.     

Label-free photoacoustic microscopy of myocardial sheet architecture

Cardiac myofibers are organized into sheet architectures, which contribute to up to 40% of the heart wall thickening for ejection of blood for circulation. It is important to delineate the sheet architecture for a better understanding of cardiac mechanisms. However, current sheet imaging technologies are limited by fixation-induced dehydration/deformation and low spatial resolution. Here we implemented high-resolution label-free photoacoustic microscopy (PAM) of the myocardial sheet architecture. With high endogenous optical-absorption contrast originating mainly from cytochrome, myoglobin, and melanin, PAM can image the unfixed, unstained and unsliced heart without introducing deformation artifacts. A fresh blood-free mouse heart was imaged by PAM ex vivo. The three-dimensional branching sheets were clearly identified within 150 [micro sign]m depth. Various morphological parameters were derived from the PAM image. The sheet thickness (80 ± 10 μm) and the cleavage height (11 ± 1 μm) were derived from an undehydrated heart for the first time. Therefore, PAM has the potential for the functional imaging of sheet architecture in ex vivo perfused and viable hearts.     

The crimson care collaborative: a student-faculty initiative to increase medical students' early exposure to primary care

The current shortage of primary care physicians (PCPs), particularly as more individuals obtain health insurance and seek primary care services, is a growing national concern. The Crimson Care Collaborative (CCC) is a joint student-faculty initiative in post-health-care-reform Massachusetts that was started with the explicit goal of attracting medical students to primary care careers. It fills a niche for student-run clinics, providing evening access to primary care services for patients without a PCP and urgent care services for patients of a Massachusetts General Hospital-affiliated internal medicine clinic, with the aim of decreasing emergency department use in both groups. Unlike other student-run clinics, CCC is integrated into the mainstream health care structure of an existing primary care clinic and, because of universal health insurance coverage in Massachusetts, can bill for its services. In addition to the clinical services offered, the student-run research team evaluates the quality of care and the patients' experiences at the clinic. This article describes the creation and development of CCC, including a brief overview of clinic operations, social services, research, laboratory services, student and patient education programs, and finance. In the wake of the Patient Protection and Affordable Care Act of 2010, CCC is an example of how students can aid the transition to universal health care in the United States and how medical schools can expose students early in their training to primary care and clinic operations.     

Tandem duplication/triplication correlated with poly-cytosine stretch variation in human mitochondrial DNA D-loop region

Somatic mutations in the mitochondrial DNA (mtDNA) displacement loop (D-loop) region have been frequently detected in various human cancers. In a previous study, we identified a polyplasmic 260-bp tandem duplication and triplication mutation in the mtDNA D-loop of one gastric cancer. In the present study, we adopted a more sensitive back-to-back polymerase chain reaction method to screen for this 260-bp tandem duplication/triplication in 197 cancers and their adjacent non-cancerous tissues. Nine samples of primary cancer (4.6%) were found to harbor the tandem duplication/triplication and these were made up of four out of 31 (12.9%) gastric cancers, two out of 45 (4.4%) breast cancers, two out of 56 (3.6%) hepatocellular cancers and one out of 32 (3.1%) colon cancers, but no tandem duplication/triplication was present in any of 33 lung cancers. We also found an expanded and polyplasmic poly-cytosine (poly-C) stretch around nucleotide position (np) 568 in eight of the 197 (4.1%) cancer patients. All the eight cancer samples carried the 260-bp tandem duplication/triplication. In addition, we detected the np 568 poly-C length variations in 11 of 234 (4.7%) peripheral blood samples of non-cancer population and the 260-bp tandem duplication in nine of the 11 cases with the np 568 poly-C length variations. These observations suggest that the occurrence of the tandem duplication/triplication in mtDNA D-loop is not specific for cancer tissues, but highly associated with the poly-C length variations around np 568.     

Regulation of autoimmune arthritis by the pro-inflammatory cytokine interferon-gamma

The pathogenesis of T cell-mediated diseases like rheumatoid arthritis (RA) has typically been explained in the context of the Th1-Th2 paradigm: the initiation/propagation by pro-inflammatory cytokines, and downregulation by Th2 cytokines. However, in our study based on the adjuvant-induced arthritis (AA) model of RA, we observed that Lewis (LEW) (RT.1(l)) rats at the recovery phase of AA showed the highest level of IFN-gamma in recall response to mycobacterial heat-shock protein 65 (Bhsp65), whereas AA-resistant Wistar-Kyoto (WKY) (RT.1(l)) rats secreted high levels of IFN-gamma much earlier following disease induction. However, no significant secretion of IL-10 or TGF-beta was observed in either strain. Furthermore, pre-treatment of LEW rats with a peptide of self (rat) hsp65 (R465), which induced T cells secreting predominantly IFN-gamma, afforded protection against AA and decreased IL-17 expression by the arthritogenic epitope-restimulated T cells. These results provide a novel perspective on the pathogenesis of autoimmune arthritis.     

Evaluation of immunochromatography and commercial enzyme-linked immunosorbent assay for rapid detection of norovirus antigen in stool samples

The efficiency of immunochromatography and commercial enzyme-linked immunosorbent assay (ELISA) kit (Denka Seiken Co. Ltd., Tokyo, Japan) were evaluated for rapid detection of norovirus (NoV) from stool specimens. A total of 503 stool specimens collected from infants and young children who suffered from acute gastroenteritis were tested for NoV by the NoV-immunochromatography kit, Denka ELISA kit, and by a monoplex RT-PCR method. The NoV-immunochromatography revealed 78.9% sensitivity, 96.4% specificity, and 92.4% efficiency with the monoplex RT-PCR method. The Denka ELISA kit had a sensitivity of 90.4%, specificity of 96.4%, and an efficiency level of 95%. The findings indicate that the newly developed NoV-immunochromatography kit provides the specificity equal to that of the Denka ELISA kit, even through the sensitivity of detection was lower. However, the advantage of the NoV-immunochromatography kit is less time consuming and simpler. The data show that both the Denka ELISA and the NoV-immunochromatography kits may be used as an alternative method for screening of NoV in stool samples.     

亚低温下脑缺血大鼠骨髓间充质干细胞迁移和梗死体积的变化

背景：关于亚低温运用到神经损伤修复领域的研究已有一些报道,但亚低温对神经干细胞在脑内移植迁移的影响还不太清楚。 目的：观察亚低温对移植入脑缺血大鼠侧脑室的骨髓间充质干细胞迁移及脑梗死体积的影响。 方法：采用Longa法永久性闭塞SD大鼠大脑中动脉制作局灶性脑缺血损伤模型,50只大鼠随机摸球法分为亚低温组、对照组、假手术组。亚低温组于移植前应用亚低温处理大鼠急性脑缺血损伤,对照组于移植前应用常温处理大鼠急性脑缺血损伤;假手术组大鼠麻醉后分离结扎右侧颈内总动脉。亚低温组和对照组在造模后24 h,在脑立体定向下经侧脑室注射移植用5-BrdU标记的骨髓间充质干细胞。经过5,14,21 d后用免疫组织化学方法检测各组大鼠脑组织BrdU阳性细胞数。 结果与结论：骨髓间充质干细胞移植第14天多数标记的骨髓间充质干细胞已经迁移至梗死灶周围,移植后亚低温组各时间点梗死灶周边皮质的BrdU阳性细胞数明显多于对照组(P < 0.05)。与对照组比较,亚低温组在移植前后各个时间点脑梗死体积均显著减小(P < 0.05)。提示移植前宿主亚低温处理可以促进骨髓间充质细胞的定向迁移,且脑梗死体积显著减小。     

A Novel Mutation in the GATA1 Gene Associated with Acute Megakaryoblastic Leukemia in a Korean Down Syndrome Patient

Although acquired mutations in the GATA1 gene have been reported for Down syndrome-related acute megakaryoblastic leukemia (DS-AMKL) in Caucasians, this is the first report of a Korean Down syndrome patient with AMKL carrying a novel mutation of the GATA1 gene. A 3-yr-old Korean girl with Down syndrome was admitted to our hospital complaining of pallor and fever. The findings of a peripheral blood smear and bone marrow study were compatible with the presence of AMKL. A chromosome study showed 48,XX,-7,+21c,+21,+r[3]/47,XX,+21c[17]. Following GATA1 gene mutation analysis, a novel mutation, c.145dupG (p.Ala49GlyfsX18), was identified in the N-terminal activation domain of the GATA1 gene. This mutation caused a premature termination at codon 67 and expression of an abnormal GATA-1 protein with a defective N-terminal activation domain, and the absence of full-length GATA-1 protein. This case demonstrates that a leukemogenic mechanism for DS-AMKL is contributed by a unique collaboration between overexpressed genes from trisomy 21 and an acquired GATA1 mutation previously seen in Caucasians and now in a Korean patient.