Analysis of orthologous gene expression between human pulmonary adenocarcinoma and a carcinogen-induced murine model

Human adenocarcinoma (AC) is the most frequently diagnosed human lung cancer, and its absolute incidence is increasing dramatically. Compared to human lung AC, the A/J mouse-urethane model exhibits similar histological appearance and molecular changes. We examined the gene expression profiles of human and murine lung tissues (normal or AC) and compared the two species' datasets after aligning approximately 7500 orthologous genes. A list of 409 gene classifiers (P value <0.0001), common to both species (joint classifiers), showed significant, positive correlation in expression levels between the two species. A number of previously reported expression changes were recapitulated in both species, such as changes in glycolytic enzymes and cell-cycle proteins. Unexpectedly, joint classifiers in angiogenesis were uniformly down-regulated in tumor tissues. The eicosanoid pathway enzymes prostacyclin synthase (PGIS) and inducible prostaglandin E(2) synthase (PGES) were joint classifiers that showed opposite effects in lung AC (PGIS down-regulated; PGES up-regulated). Finally, tissue microarrays identified the same protein expression pattern for PGIS and PGES in 108 different non-small cell lung cancer biopsies, and the detection of PGIS had statistically significant prognostic value in patient survival. Thus, the A/J mouse-urethane model reflects significant molecular details of human lung AC, and comparison of changes in orthologous gene expression may provide novel insights into lung carcinogenesis.     

Laboratory-based surveillance and molecular epidemiology of influenza virus in Taiwan

A laboratory-based surveillance network of 11 clinical virological laboratories for influenza viruses was established in Taiwan under the coordination of the Center for Disease Control and Prevention (CDC), Taiwan. From October 2000 to March 2004, 3,244 influenza viruses were isolated, including 1,969 influenza A and 1,275 influenza B viruses. The influenza infections usually occurred frequently in winter in the northern hemisphere. However, the influenza seasonality in Taiwan was not clear during the four seasons under investigation. For example, the influenza A viruses peaked during the winters of 2001, 2002, and 2003. However, some isolated peaks were also found in the summer and fall (June to November) of 2001 and 2002. An unusual peak of influenza B also occurred in the summer of 2002 (June to August). Phylogenetic analysis shows that influenza A isolates from the same year were often grouped together. However, influenza B isolates from the year 2002 clustered into different groups, and the data indicate that both B/Victoria/2/87-like and B/Yamagata/16/88-like lineages of influenza B viruses were cocirculating. Sequence comparison of epidemic strains versus vaccine strains shows that many vaccine-like Taiwanese strains were circulating at least 2 years before the vaccine strains were introduced. No clear seasonality of influenza reports in Taiwan occurred in contrast to other more continental regions.     

Increased CD4+ T-lymphocyte senescence fraction in advanced human immunodeficiency virus type 1 infection

Human immunodeficiency virus type 1 (HIV-1) infection is accompanied by peripheral CD4+ T-cell losses. CD4+ T-cell numbers often increase during antiviral treatment of acquired immune deficiency syndrome (AIDS), however, alterations in the CD4+ T-cell repertoire have not been completely corrected for these patients. Such individuals remain at increased risk of infection. Although senescence of the CD4+ T cells has not been adequately evaluated for advanced HIV-1 infection, hypothetically, replicative senescence could complicate therapeutic reconstitution of the CD4+ T cells in AIDS. In this study, correlates of replicative senescence, terminal restriction fragment (TRF) length and percentage short (< 5.0 kb) telomeric DNA (senescence fraction), were measured for the CD4+ T cells of HIV-1-infected patients with peripheral CD4+ T-cell counts of < 200/mm3. The results show that for advanced HIV-1 infection the TRF length of the CD4+ T cells is decreased (P < 0.01), and the senescence fraction increased (P < 0.05), when compared with uninfected controls. These findings suggest that cellular senescence may contribute to disruption of CD4+ T-cell diversity observed following the therapeutic, immunologic reconstitution of AIDS.     

Evaluation of screened blood donations for human immunodeficiency virus type 1 infection by culture and DNA amplification of pooled cells

BACKGROUND. Reports of transmission of the human immunodeficiency virus type 1 (HIV-1) from transfusions of screened blood and reports of silent, antibody-negative HIV-1 infections in persons at high risk continue to foster concern about the safety of the blood supply. Previous estimates of the risk of HIV-1 range from 1 in 38,000 to 1 in 300,000 per unit of blood but are based on either epidemiologic models or the demonstration of seroconversion in recipients. METHODS. We isolated peripheral-blood mononuclear cells from blood that was fully screened and found to be seronegative, combined them into pools of cells from 50 donors, and tested them for HIV-1 by viral culture and the polymerase chain reaction, using protocols specifically adapted for this analysis. RESULTS. The 1530 pools of mononuclear cells were prepared from 76,500 blood donations made in San Francisco between November 1987 and December 1989. Of these pools, 1436 (representing 71,800 donations) were cultured successfully; 873 (43,650 donations) were evaluated by the polymerase chain reaction. Only one pool was confirmed as HIV-1--infected by both methods. After adjustment for sample-based estimates of the sensitivity of the detection systems using culture and the polymerase chain reaction, the probability that a screened donor will be positive for HIV-1 was estimated as 1 in 61,171 (95 percent upper confidence bound, 1 in 10,695). CONCLUSIONS. Silent HIV-1 infections are exceedingly rare among screened blood donors, so the current risk of HIV-1 transmission from blood transfusions, even in high-prevalence metropolitan areas, is extremely low.     

CpG island methylation in aberrant crypt foci of the colorectum

Aberrant crypt foci (ACF) are postulated to be the earliest precursor lesion in colorectal carcinogenesis, and CpG island methylation has been described as an important molecular pathway. We therefore studied methylation in ACF from patients with familial adenomatous polyposis (FAP) or sporadic colorectal cancer. We assessed methylation status of the p16 tumor suppressor gene, MINT1 (methylated in tumor 1), MINT2, MINT31, O(6)-methylguanine-DNA methyltransferase gene, and hMLH1 mismatch repair gene. We compared methylation to ACF histopathology, K-ras proto-oncogene mutation, loss of heterozygosity at chromosome 1p, and microsatellite instability. Methylation was present in 34% (21 of 61) of ACF, including both FAP and sporadic types, but was more frequent in sporadic ACF [53% (18 of 34) versus 11% (3 of 27), P = 0.002], especially dysplastic sporadic ACF [75% (3 of 4) versus 8% (2 of 24), P = 0.004]. MINT31 was more frequently methylated in heteroplastic ACF than dysplastic ACF [35% (11 of 31) versus 7% (2 of 30), P = 0.01]. Strong associations of ACF methylation with K-ras mutation (P = 0.007) and with loss of chromosome 1p (P = 0.04) were observed, but methylation was the only molecular abnormality identified in 16% (10 of 61) of ACF. Our findings suggest that methylation in ACF is an early event in the pathogenesis of a subset of colorectal carcinomas, and that ACF from FAP patients and patients with sporadic colorectal cancer have distinct epigenetic changes that reflect differences in molecular pathogenesis.     

Factors affecting the outcome of distal realignment for patellofemoral disorders of the knee

This study correlated the risk factors with the clinical outcome of distal realignment for patellofemoral disorders in 48 patients with 53 knees with 25 to 96 months follow-up. The indications for surgery included pain and disability due to patellofemoral disorders with failure of at least 6 months of conservative treatments. The evaluations included pain scores, Lysholm functional scores and radiographs of the knee. The overall results were satisfactory in 47 knees (88.7%) and unsatisfactory in six knees (11.3%). There was no correlation of the clinical results with age, sex, body weight and body height, preoperative pain scores and Lysholm scores. However, the clinical outcome correlated with the severity of articular damage and the correction of patellar malalignment. Error in patient selection and inadequate surgical technique were attributable to poor outcomes.     

Laforin preferentially binds the neurotoxic starch-like polyglucosans, which form in its absence in progressive myoclonus epilepsy

Lafora disease (LD) is a fatal and the most common form of adolescent-onset progressive epilepsy. Fulminant endoplasmic reticulum (ER)-associated depositions of starch-like long-stranded, poorly branched glycogen molecules [known as polyglucosans, which accumulate to form Lafora bodies (LBs)] are seen in neuronal perikarya and dendrites, liver, skeletal muscle and heart. The disease is caused by loss of function of the laforin dual-specificity phosphatase or the malin E3 ubiquitin ligase. Towards understanding the pathogenesis of polyglucosans in LD, we generated a transgenic mouse overexpressing inactivated laforin to trap normal laforin's unknown substrate. The trap was successful and LBs formed in liver, muscle, neuronal perikarya and dendrites. Using immunogold electron microscopy, we show that laforin is found in close proximity to the ER surrounding the polyglucosan accumulations. In neurons, it compartmentalizes to perikaryon and dendrites and not to axons. Importantly, it binds polyglucosans, establishing for the first time a direct association between the disease-defining storage product and disease protein. It preferentially binds polyglucosans over glycogen in vivo and starch over glycogen in vitro, suggesting that laforin's role begins after the appearance of polyglucosans and that the laforin pathway is involved in monitoring for and then preventing the formation of polyglucosans. In addition, we show that the laforin interacting protein, EPM2AIP1, also localizes on the polyglucosan masses, and we confirm laforin's intense binding to LBs in human LD biopsy material.     

Visuospatial impairments in aged canines (Canis familiaris): the role of cognitive-behavioral flexibility

This study used a novel delayed nonmatching-to-position task to compare visuospatial learning and memory in young and aged beagle dogs (Canis familiaris). The task used 3, rather than 2, spatial locations, which markedly increased difficulty. There were striking age differences in acquisition. Most of the aged canines did not learn the task, and those that did showed impaired learning when compared with the young canines. The aged canines also showed reduced maximal working memory capacity compared with the young canines. Analysis of the response patterns of individual canines indicated that the deficits were related to the use of ineffective strategies and inflexibility in strategy modification.     

T-cell receptor V beta selectivity in T-cell clones alloreactive to HLA-Dw14.

The HLA-DR4 subtypes Dw14 and Dw4 are T-cell-defined allospecificities encoded by the DRB1*0404 and DRB1*0401 genes, respectively. Although these allelic subtypes differ in only two amino acids, allorecognition between Dw14 and Dw4-positive individuals is brisk. This provides an opportunity to analyze T-cell receptor (TCR) usage in a very limited and specifically targeted case, namely the Dw4 anti-Dw14 allogeneic T-cell response. The variable (V), diversity (D), and joining (J) region sequences of the TCR beta chain from two different Dw14-specific alloreactive T-cell clones derived from a Dw4 donor were examined. Clone EMO25 recognized the Dw14.1, Dw14.2, and Dw15 subtypes, which share a DRB1 polymorphism at codon 71 on a DR4 background, while clone EMO36 reacted with only the Dw14.1 subtype associated with polymorphisms at codons 71 and 86. TCR beta cDNA from each clone was amplified using an anchored polymerase chain reaction (PCR) and subsequently expanded with V beta- and C beta-specific primers for asymmetric PCR and direct DNA sequencing. Both clones were found to express the same TCR V beta 8.2 gene segment; however, they have several different residues within the V beta-D beta-J beta junctional regions. V beta 8 usage was also enriched in polyclonal cells obtained from mixed lymphocyte cultures performed between the Dw4 and Dw14 responder-stimulator combination from which EMO25 and EMO36 were derived.