Identification by two-dimensional electrophoresis of a new adhesin expressed by a low-passaged strain of Mycoplasma bovis

A significant decrease in adherence rates of Mycoplasma bovis to bovine bronchial epithelial (BBE) cells has been observed after passage of the organism in artificial medium. Analysis of the proteins expressed by M. bovis isolate 2610 by two-dimensional (2-D) electrophoresis demonstrated differences between the cells harvested after the 7th and 116th passage. Three silver-stained prominent spots observed in 2-D electrophoretic separation of protein extracts of the lower-passaged cells were considerably less strongly expressed in the sample from higher-passaged cells. These spots had a molecular mass of approximately 24 kDa and an isoelectric point of about 5. The mass spectrometry analysis of these trypsin-sensitive proteins led to their identification as a unique new member of the Vsps family of membrane-associated proteins. Serum from a mouse immunized with these proteins significantly reduced adherence of M. bovis to BBE cells. This result underlines the function of this new Vsp in adherence of M. bovis to host cells.     

Hereditary hemochromatosis: genetics, pathogenesis, and clinical management

Recent findings have led to major advances in our understanding of genetics and pathophysiology of hereditary hemochromatosis. Many crucial genes and molecules have come to light, and the complex interrelationships between them are being studied. However, several questions still remain unanswered. Availability of genotyping has changed the approach to diagnosis, and serum markers hold promise for prognostication. However, the effectiveness of population screening continues to be an area of controversy.Finally, there is a promise of development of newer therapeutic modalities based on our understanding of the mechanism of iron absorption. In this review, we describe the current state of understanding in the clinical features, pathophysiology and treatment of hereditary hemochromatosis.     

Randomized phase II study of weekly docetaxel plus trastuzumab versus weekly paclitaxel plus trastuzumab in patients with previously untreated advanced nonsmall cell lung carcinoma

BACKGROUND: Trastuzumab is a monoclonal antibody directed against the human epidermal growth factor receptor-2 (HER-2). Nonsmall cell lung carcinoma (NSCLC) overexpresses HER-2 protein in approximately 20% of cases. In the current study, the authors combined trastuzumab with weekly taxanes in an attempt to improve outcomes over standard chemotherapy in patients with advanced NSCLC. METHODS: The primary objective was to determine whether docetaxel plus trastuzumab or paclitaxel plus trastuzumab was the superior regimen based on response and toxicity, and to determine whether either regimen was appropriate for further testing in a randomized Phase III trial. After stratification based on the results of HER-2 immunohistochemistry, chemotherapy-naive patients were randomized to receive trastuzumab plus docetaxel or trastuzumab plus paclitaxel. The study was designed so patients with or without HER-2 overexpression would be distributed equally between the study arms. RESULTS: Immunohistochemistry for HER-2 protein expression was attempted for 182 pathologic samples from 169 patients. Twenty-eight of the 179 evaluable samples (16%) revealed 2+ or 3+ staining. The objective response rate was 23% (7 of 30 patients) in the patients treated with docetaxel plus trastuzumab and 32% (11 of 34 patients) in the patients treated with paclitaxel plus trastuzumab (P=0.76, Wilcoxon test). No difference was noted in the median survival (16 mos vs. 14 mos) or 1-year survival (57% vs. 55%) (P=0.998). Toxicities were mild in both treatment arms. No difference with regard to response rates or survival was noted between HER-2-positive (2+ or 3+) and HER-2-negative (0-1+) patients. CONCLUSIONS: The expression of HER-2 protein in patients with advanced NSCLC in this study was found to be similar to that reported in previous series. The response rates and toxicities for patients treated with docetaxel and trasuzumab or paclitaxel and trasuzumab were not significantly different, though survival in both arms was better than expected. HER-2 expression status did not appear to affect outcomes for this uniform group of patients who were treated in a comparable fashion. Because of the infrequency of HER-2 overexpression, and the absence of improved outcomes in patients with NSCLC who were treated with trastuzumab plus chemotherapy in other studies, neither regimen tested will be advanced to a Phase III trial.     

Drug Burden Index and change in cognition over time in community-dwelling older men: the CHAMP study

Objective: Anticholinergic and sedative medications are associated with acute cognitive impairment, but the long-term impact on change in cognition is unclear. This study investigated the effect of anticholinergic and sedative medications, quantified using the Drug Burden Index (DBI), on change in cognition over time in community-dwelling older men.

Methods: This was a prospective cohort study of men aged ≥70 years in Sydney, Australia. DBI was assessed at baseline, 2, and 5 years. Cognitive performance was assessed using the Mini-Mental State Exam (MMSE) at each wave. Logistic quantile mixed-effects modelling was used to assess the adjusted effect of DBI on the median MMSE-time profile. Analyses were restricted to men with English-speaking backgrounds (n?=?1059, 862, and 611 at baseline, 2, and 5 years).

Results: Overall, 292 (27.7%), 258 (29.9%), and 189 (31.3%) men used anticholinergic or sedative medications at baseline, 2, and 5 years. There was a concave relationship between MMSE and time, where higher DBI corresponded to lower MMSE scores (coefficient: ?0.161; 95% CI: ?0.250 to ?0.071) but not acceleration of declining MMSE over time.

Conclusions: Exposure to anticholinergic and sedative medications is associated with a small impairment in cognitive performance but not decline in cognition over time.

• KEY MESSAGES

• Exposure to anticholinergic and sedative medications, quantified using the Drug Burden Index, is associated with small cross-sectional impairments in cognitive performance.

• There was no evidence that exposure to anticholinergic and sedative medications is associated with accelerating decline in cognitive performance over a 5-year follow-up.

• Older people taking anticholinergic and sedative medications may derive immediate but small benefits in cognitive performance from clinical medication reviews to minimize or cease prescribing of these medications.

     

Evolution of body weight parameters up to 3 years after solid organ transplantation: The prospective Swiss Transplant Cohort Study

Obesity and weight gain are serious concerns after solid organ transplantation (Tx); however, no unbiased comparison regarding body weight parameter evolution across organ groups has yet been performed. Using data from the prospective nationwide Swiss Transplant Cohort Study, we compared the evolution of weight parameters up to 3 years post‐Tx in 1359 adult kidney (58.3%), liver (21.7%), lung (11.6%), and heart (8.4%) recipients transplanted between May 2008 and May 2012. Changes in mean weight and body mass index (BMI) category were compared to reference values from 6 months post‐Tx. At 3 years post‐Tx, compared to other organ groups, liver Tx recipients showed the greatest weight gain (mean 4.8±10.4 kg), 57.4% gained >5% body weight, and they had the highest incidence of obesity (38.1%). After 3 years, based on their BMI categories at 6 months, normal weight and obese liver Tx patients, as well as underweight kidney, lung and heart Tx patients had the highest weight gains. Judged against international Tx patient data, the majority of our Swiss Tx recipients’ experienced lower post‐Tx weight gain. However, our findings show weight gain pattern differences, both within and across organ Tx groups that call for preventive measures.     

Gene copy mapping of the ERBB2/TOP2A region in breast cancer

ERBB2 is one of the most important oncogenes in breast cancer, and its disordered expression is commonly associated with gene amplification. Amplification of at least one gene near ERBB2, topoisomerase IIalpha (TOP2A), has been shown to be clinically significant, but the prevailing patterns of gene amplification in this region of chromosome arm 17q have not been studied systematically in clinical cases of breast cancer. For characterizing this region, a commercial ERBB2-containing contig probe and 7 probes prepared from single overlapping BAC and P1 clones lying telomeric to ERBB2 and including TOP2A were hybridized to 77 ERBB2-amplified archival breast tumor specimens from 75 patients. The 7 single-clone probes covered a region of approximately 650 kb starting 114 kb telomeric to ERBB2. Amplification of the ERBB2 contig target alone was found in 32% of the tumors, whereas all 8 probe targets were amplified in 12% of the tumors, based on an amplification criterion of there being more than or equal to 2 targets per chromosome 17 centromere. When one of the 7 overlapping probes encompassing TOP2A indicated amplification within a specimen, all probes telomeric to that probe usually showed amplification. Only 5 specimens had regions of normal or deleted targets separating 2 amplified targets. Also, tumors that showed deletion of TOP2A usually showed deletion of one or more contiguous targets. The observed patterns of amplification and deletion are consistent with the break-fusion-bridge model for gene amplification. TOP2A was amplified in 25% of all tumor specimens and was deleted in 24%, based on a deletion criterion of there being fewer than or equal to 0.75 targets per chromosome 17 centromere. Considering the relevance of the TOP2A gene product to anthracycline therapy and the wealth of other cancer-associated genes within the ERBB2/TOP2A region, the pattern of amplification and deletion near ERBB2 and TOP2A may have a dramatic effect on the malignant potential of breast carcinomas and their response to therapy.     

Tumorigenicity of mouse T lymphoma cells is controlled by the level of major histocompatibility complex class I H-2Kk antigens

We have previously found that an increased tumorigenicity and spontaneous metastatic potential of BW5147-derived T lymphoma cells was associated with a decrease in major histocompatibility complex (MHC) class I H-2K^k antigen expression. This suggested that H-2K^k antigens may control the tumorigenic potential of BW T lymphoma cells. Our current experiments aimed to prove this association by specifically altering H-2K^k expression by gene transfection. Transfected cells expressing a high level of H-2K^k antigens were significantly less tumorigenic and metastatic after subcutaneous inoculation. However, there was selectionin vivo for cells expressing a reduced level of H-2K^k antigens, which concomitantly led to an increased tumorigenicity. These data further confirmed the strong association between H-2K^k expression and tumorigenicity. We subsequently tested whether the immune system is implicated in this phenomenon by inoculating the H-2K^k transfectants into irradiated, immunocompromised recipients. Our results indicate that the reduced tumorigenicity of the BW H-2K^k transfectants is due to an immune rejection mechanism, mediated by CD8⁺ immune effector cells, as revealed byin vivo depletion experiments with anti-CD8 antibodies. Hence, we hereby demonstrated that H-2K^k antigens increased the immunogenicity of BW cells, via a CD8-dependent mechanism, which consequently reduced their tumorigenicity.     

A comparison of Thermo Electron RSV OIA to viral culture and direct fluorescent assay testing for respiratory syncytial virus.

BACKGROUND: Rapid diagnostic methods for respiratory syncytial virus are useful tools available for the clinician. OBJECTIVES: The Thermo Electron RSV OIA (optical immunoassay kit) was prospectively compared with direct immunofluorescent assay and viral culture at Primary Children's Medical Center, Salt Lake City, Utah. STUDY DESIGN: Specimens from three hundred and thirty patients exhibiting respiratory symptoms were collected for testing by the three methods above. Several specimens were positive by both OIA and DFA with a negative culture result. These culture results were verified by RT-PCR analysis. RESULTS: Overall, 107 specimens were positive for RSV by the reference tests (culture or RT-PCR). DFA analysis identified an additional 40 patient specimens positive for other respiratory viruses. Compared to the reference tests the sensitivity, specificity, positive, and negative predictive values of the OIA for detection of RSV were 87.9%, 99.6%, 98.9% and 94.5%, respectively. CONCLUSIONS: The rapid OIA assay format proved to be cost effective, and simple to use in comparison to DFA and viral culture. Negative rapid test results should still be confirmed with a secondary test.     

Passive serum antibody causes temporary recovery from influenza virus infection of the nose, trachea and lung of nude mice.

BALB/c normal and nude mice were infected with a non-lethal mouse-passaged A/PC/1/73 (H3N2) influenza virus in order to assess the role of T cells on the course of disease of the nose, trachea and lung. The tracheal epithelium of both mouse strains was desquamated by 3 days after infection. Although normal regeneration began, nude mice never completed that regeneration whereas normal mice had fully regenerated tracheas by Day 14. This failure to complete the recovery was also evident from the continued virus shedding by the nude mouse. In order to assess the role of serum antibody on recovery from infection, ferret, goat or mouse antibody to H3N2 influenza virus was passively administered to nude mice after infection. It resulted in a transient decrease in virus shedding from the nose, trachea and lung, and complete but temporary regeneration of the tracheal epithelium. However, later in the course of the infection, when serum antibody levels were no longer detectable, the tracheal epithelium of these animals redesquamated and large amounts of virus were again shed from nose, trachea and lungs. We conclude that: (i) desquamation of the ciliated epithelium of the trachea is not T-cell dependent; and (ii) serum antibody can contribute to temporary recovery from infection, but by itself is insufficient for permanent recovery of the nose, trachea or lung.