Asymptomatic cytomegalovirus infection is associated with increased risk of new-onset diabetes mellitus and impaired insulin release after renal transplantation

AIMS/HYPOTHESIS

The human cytomegalovirus (CMV) may increase the risk of diabetes mellitus, but the literature is scarce. The present study was designed to test the hypothesis that asymptomatic CMV infection is associated with increased risk of new-onset diabetes after renal transplantation, and to assess the impact of asymptomatic CMV infection on OGTT-derived estimates of insulin release and insulin action.

METHODS

A total of 160 consecutive non-diabetic renal transplant recipients on cyclosporine (Sandimmun Neoral)-based immunosuppression were closely monitored for CMV infection during the first 3 months after transplantation. All patients underwent a 75-g OGTT at 10 weeks. Excluded from the analyses were 36 patients with symptomatic CMV infection (disease).

RESULTS

The incidence of new-onset diabetes was 6% in a control group of recipients without CMV infection (4/63) and 26% in the group with asymptomatic CMV infection (16/61). Asymptomatic CMV infection was associated with a significantly increased risk of new-onset diabetes (adjusted odds ratio: 4.00; 95% CI: 1.19 to 13.43, p=0.025). The group of patients with CMV infection had a significantly lower median insulin release than controls.

CONCLUSIONS/INTERPRETATION

Our findings support the hypothesis that asymptomatic CMV infection is associated with increased risk of new-onset post-transplant diabetes mellitus, and suggest that impaired insulin release may involve one pathogenetic mechanism.

The Influence of Hyperbaric Oxygenation (HBO) on Proliferation and Differentiation of Human Keratinocyte Cultures In Vitro

A drop in tissue oxygen partial pressure below 30 mm Hg as a result of reduced perfusion in an extensive area of acute skin damage, or where a large number of chronic skin defects occur, inhibits collagen synthesis and neoangiogenesis in the various phases of wound healing. Subsequent granulation and epithelialisation are correspondingly impaired.Hyperbaric oxygenation is now recognised as a valuable supplementary method of treatment for problematic wounds. Stimulation of fibroblast and endothelial cell proliferation through Hyperbaric oxygenation has been demonstrated in numerous studies.The aim of this study was to investigate the effect of hyperbaric oxygen treatment on the proliferation and differentiation of human keratinocyte cultures.The influence of hyperbaric oxygenation on the proliferation of human keratinocyte cultures was demonstrated using flow-through cytometry and a fluorescence activated cell sorter, which detects fluorescence intensity following incorporation of 5-bromo-2'-deoxyuridine in cell DNA.The degree of cell differentiation was deduced from the expression of various components of the cytoskeleton, such as cytokeratin 10 and involukrin, the production of which was quantified through the determination of monoclonal antibodies against cytokeratin 10 and involukrin from measurements of fluorescence activity in a flow-through cytometer.Hyperbaric oxygenation of cell cultures in vitro did not produce a significantly higher rate of cell proliferation, so that no increase in vitality was observed.An interesting observation following exposure to hyperbaric oxygen was the marked increase in expression of both cytokeratin 10 and involukrin, as an indication of accelerated cell differentiation.

Gene expression profiles derived from single cells in human postmortem brain

The study of postmortem human brain tissue remains the basis for the understanding of many CNS disorders and to verify data obtained in experimental studies. So far, however, gene expression profiling in cellular sub-populations derived from human postmortem brain was hampered by several technical drawbacks. Here, we describe a method that allows the generation of mRNA expression profiles from single neurons. Dopaminergic neurons from different midbrain areas including substantia nigra, central gray substance and ventral tegmental area were identified and isolated by immuno-laser capture microscopy (LCM). Expression profiles were generated from microdissected cells using a modified RNA fingerprinting protocol. Using this approach, we were able to generate specific RNA fingerprints at a high resolution from phenotype-specific single neurons. Polymorphic fragments were isolated from gels and differential gene expression was confirmed by real-time PCR using gene-specific primer pairs and hybridization probes. The method described here is easy to use and reliable for profiling gene expression at the single cell level in human postmortem brain. It could therefore be valuable to open new insights into the molecular pathogenesis of CNS disorders.

Association of Infratentorial Brain Arteriovenous Malformations With Hemorrhage at Initial Presentation

Background and Purpose— The goal of this study was to analyze the association of hemorrhagic presentation with infratentorial brain arteriovenous malformations (AVMs).

Methods— The 623 consecutive, prospectively enrolled patients from the Columbia AVM Databank were analyzed in a cross-sectional study. Clinical presentation (diagnostic event) was categorized as intracranial hemorrhage or nonhemorrhagic presentation. From brain imaging and cerebral angiography, AVM location was classified as either infratentorial or supratentorial. Univariate and multivariate statistical models were applied to test the effect of age, sex, AVM size and location, venous drainage pattern, and associated (ie, feeding artery or intranidal) arterial aneurysms on the likelihood of hemorrhage at initial AVM presentation.

Results— Of the 623 patients, 72 (12%) had an infratentorial and 551 (88%) had a supratentorial AVM. Intracranial hemorrhage was the presenting symptom in 283 patients (45%), and infratentorial AVM location was significantly more frequent (18%) among patients who bled initially (6%; odds ratio [OR], 3.60; 95% confidence interval [CI], 2.09 to 6.20). This difference remained significant (OR, 1.99; 95% CI, 1.07 to 3.69) in the multivariate logistic regression model controlling for age, sex, AVM size, deep venous drainage, and associated arterial aneurysms. In the same model, the effect of other established determinants for AVM hemorrhage—ie, AVM size (in 1-mm increments; OR, 0.95; 95% CI, 0.94 to 0.96), deep venous drainage (OR, 3.09; 95% CI, 1.87 to 5.12), and associated aneurysms (OR, 2.78; 95% CI, 1.76 to 4.40)—remained significant.

Conclusions— Our findings suggest that infratentorial AVM location is independently associated with hemorrhagic AVM presentation.

Perfusion and molecular diffusion-weighted MR imaging of the brain: in vivo assessment of tissue alteration in cerebral ischemia

The combined use of perfusion imaging (PI) and diffusion-weighted imaging (DWI) is opening a new window into the processes that occur during the first hours of ischemia. DWI detects changes in molecular diffusion associated with cytotoxic edema. PI characterizes the degree of regional hypoperfusion. Regions showing mismatches between DWI and PI, i.e. hypoperfused areas with normal diffusion behavior are considered potentially salvageable. We present results of 11 patients with an occlusion of the middle cerebral artery stem and spontaneous stroke evolution. Whereas the infarct was clearly visible on initial DWI and PI, surrounding tissue at risk of infarction was marked in all patients by an increased blood volume and transit time, but only in a subgroup (n = 3) where alteration were more pronounced this tissue at risk was progressively infarcted. These human DWI and PI data show alterations in the area of tissue at risk which correlates with infarct progression.

Alterations in p53 predict response to preoperative high dose chemotherapy in patients with gastric cancer

AIMS

To evaluate the usefulness of molecular markers in predicting histopathological and clinical response to preoperative high dose chemotherapy (HDCT) and survival of patients with advanced gastric cancer.

METHODS

In a phase II trial, 25 patients with metastatic gastric cancer received preoperative tandem HDCT consisting of etoposide, cisplatin, and mitomycin, followed by autologous bone marrow transplantation to achieve surgical resectability. Samples before and after treatment, from normal and tumour tissue, were characterised histopathologically, and both p53 and BAX expression was analysed by immunohistochemistry. Pretreatment formalin fixed, paraffin wax embedded samples from normal and tumour tissue were microdissected, and the extracted DNA was preamplified using improved primer extension preamplification polymerase chain reaction. Detection of microsatellite instability (MSI) or loss of heterozygosity (LOH) was performed using markers for p53, BAX, BAT25, BAT26, D2S123, D17S250, and APC. Exons 5-9 of the p53 gene were sequenced directly on ABI 373.

RESULTS

Four parameters were significantly associated with response to chemotherapy and prolonged overall survival: positive p53 immunostaining, positive p53 mutation status before chemotherapy, strong histological regression induced by preoperative HDCT, and surgical treatment. Patients's sex or age, tumour location or stage, lymph node status, Lauren classification, MSI, or LOH did not influence duration of survival significantly in this high risk population.

CONCLUSION

Positive p53 immunostaining and p53 mutation status in pretreatment tumour biopsies might be useful molecular predictors of response and prognosis in patients with advanced gastric cancer treated by preoperative HDCT.

[Current aspects of electrical cardioversion in patients with persistent atrial fibrillation]

BACKGROUND

Results of recent studies suggest new aspects in the concept of the management of patients with atrial fibrillation. Current trials comparing rhythm control by cardioversion followed by antiarrhythmic drug therapy with heart rate control only showed that rhythm control was not superior to rate control.

SPECIAL ASPECTS OF ELECTRICAL CARDIOVERSION

However, some subgroups of patients with frequent or severe symptoms and younger patients with structurally normal hearts may benefit from cardioversion. In patients with persistent atrial fibrillation, sinus rhythm can be restored in approximately 90% by direct current transthoracic cardioversion. Transthoracic cardioversion is effective and safe, if anticoagulation is used. Attempts have been made to improve the success rate by new techniques. However, definition of subgroups and stabilization of sinus rhythm are ongoing issues of debate.

Cerebrovascular reactivity in major depression: a pilot study

OBJECTIVE

There are a growing number of reports that depression may increase the risk of stroke. Little is known, however, about the pathophysiologic mechanisms underlying this association. Cerebrovascular reactivity (CVR) reflects the compensatory dilatory capacity of cerebral arterioles to a dilatory stimulus and is an important mechanism to provide constant cerebral blood flow. We hypothesized that CVR is reduced in patients with major depression, thus contributing to the association between depression and stroke.

METHODS

We assessed CVR in 33 patients with unipolar depression and 26 healthy controls by calculating the increase in cerebral blood flow velocity after stimulation with acetazolamide. Blood flow velocities were measured by transcranial Doppler ultrasound.

RESULTS

Cerebrovascular reactivity was significantly reduced in depressed patients. Smoking was also associated with a significant reduction in CVR, whereas age and gender had no significant influence.

CONCLUSIONS

Cerebrovascular reactivity appears to be impaired in major depression. Further studies should clarify the mechanisms leading to this reduced CVR.

Use of the alkaline in vivo Comet assay for mechanistic genotoxicity investigations

The alkaline Comet assay was used to investigate the in vivo genotoxicity of 17 compounds. Altogether 21 studies were conducted with these compounds. The investigations were triggered for various reasons. The main reason for performing the studies was to evaluate the in vivo relevance of in vitro genotoxicity findings with 10 compounds. Eight of these compounds showed no effects in the in vivo Comet assay while two compounds induced altered DNA migration patterns in specific organs. The remaining seven compounds were tested to follow up on neoplastic/preneoplastic or chronic toxicity changes as detected in specific target organs identified in rodent studies, to investigate the possibility of site-of-contact genotoxicity and to test the liver as a target organ for a suspected reactive metabolite. For the studies, various organs of rodents were analyzed, depending on the suspected properties of the compounds, including liver, jejunum, leukocytes, stomach mucosa, duodenum, lung and kidney. All tissues were amenable to investigation by gel electrophoresis after simple disaggregation of organs by means of mincing or, in the case of epithelial cells from the gastrointestinal tract, scraping off cells from the epithelium. In conclusion, the Comet assay was found to be a reliable and robust test to investigate in vivo genotoxicity in a variety of rodent organs. Therefore, it is concluded that in vivo Comet assay data are useful for elucidating positive in vitro genotoxicity findings and to evaluate genotoxicity in target organs of toxicity.

[FISH analysis in the differential diagnosis of flat urothelial lesions using tissue microarrays]

AIMS

FISH technology offers an additional tool in the diagnosis of precancerous and malignant lesions of the urinary tract from cytological specimens. Here, we examined the relevance of chromosomal imbalance in flat urothelial lesions using FISH on paraffin-embedded tissue. In addition, the status of Her2/neu and STK15, a key molecule in the development of aneuploidy, was evaluated.

METHODS

Flat lesions (normal urothelium, hyperplasia, reactive atypia, dysplasia and Carcinoma in situlCis) of 73 patients were analyzed in respect of chromosome 3, 7, 17 polysomy, deletion of p16, status of HER2/neu and of STK15 by FISH (UroVysion, PathVysion, Vysis) and immunohistochemistry (HercepTest, DAKO) using tissue microarrays. The data were correlated with histology.

RESULTS AND CONCLUSIONS

Aneusomy of at least one of the chromosomes usually correlates with the histology of carcinoma in situ or invasive tumor growth. Reactive atypias, rarely showing chromosomal imbalance, can be distinguished from Cis in the majority of investigated cases, but the FISH technique is not able to differentiate reactive atypia from mild dysplasia. About 30 % of the non-neoplastic lesions like urothelial hyperplasia and normal urothelium display polysomy of at least one chromosome in more than 20% of all cells, indicating an elevated risk towards a synchronous development of a higher dysplastic lesion (i.e. Cis). Polysomy of one of three investigated chromosomes (3, 7, 17) occurs randomly within all lesions. A deletion of the p16 locus is most frequently observed in aneuploid lesions. Altered Her2/neu expression patterns are frequently observed in malignant and dysplastic lesions but also in 25 % of the non-neoplastic lesions. An overexpression of Her2/ neu is found in 10-20% of invasive urothelial carcinomas and occasionally in Cis (5 %). However, the Her2/neu gene locus is not amplified in these samples. Gene amplification of STK15 was seen in tumors as well as in normal urothelium but it is still unclear whether it indicates an elevated risk towards the development of manifest urothelial tumors.

A strategy to reduce the numbers of fish used in acute ecotoxicity testing of pharmaceuticals

The pharmaceutical industry gives high priority to animal welfare in the process of drug discovery and safety assessment. In the context of environmental assessments of active pharmaceutical ingredients (APIs), existing U.S. Food and Drug Administration and draft European regulations may require testing of APIs for acute ecotoxicity to algae, daphnids, and fish (base-set ecotoxicity data used to derive the predicted no-effect concentration [PNECwater] from the most sensitive of three species). Subject to regulatory approval, it is proposed that testing can be moved from fish median lethal concentration (LC50) testing (typically using > or = 42 fish/API) to acute threshold tests using fewer fish (typically 10 fish/API). To support this strategy, we have collated base-set ecotoxicity data from regulatory studies of 91 APIs (names coded for commercial reasons). For 73 of the 91 APIs, the algal median effect concentration (EC50) and daphnid EC50 values were lower than or equal to the fish LC50 data. Thus, for approximately 80% of these APIs, algal and daphnid acute EC50 data could have been used in the absence of fish LC50 data to derive PNECwater values. For the other 18 APIs, use of an acute threshold test with a step-down factor of 3.2 is predicted to give comparable PNECwater outcomes. Based on this preliminary scenario of 91 APIs, this approach is predicted to reduce the total number of fish used from 3,822 to 1,025 (approximately 73%). The present study, although preliminary, suggests that the current regulatory requirement for fish LC50 data regarding APIs should be succeeded by fish acute threshold (step-down) test data, thereby achieving significant animal welfare benefits with no loss of data for PNECwater estimates.

[Precancerous conditions in the urothelium. Early detection and molecular understanding through endoscopic fluorescence diagnosis]

Fluorescence diagnosis after application of 5-aminolevulinic acid (ALA) detects red-fluorescing preneoplastic and neoplastic lesions using light excitation. The principle of the method is the relative tumor-selective accumulation of the metabolite protoporphyrin IX (PPIX), which is built intracellularly out of exogenously applied ALA. The early detection of tumors and especially preneoplasias is an ideal prerequisite for genetic analysis of these lesions. With this approach, methods such as fluorescence in situ hybridization and loss of heterozygosity analysis for deletion mapping as well as gene sequencing data could be compared. New data are presented on deletions, numeric chromosomal aberrations, and oligoclonality of tumors found in about 30% of cases. The phenomenon of tumor-selective fluorescence was further investigated by parallel biochemical analysis, which showed marked differences in heme metabolism. The analysis of gene and protein expression may aid in identifying tumor-specific molecules associated with heme metabolism.

Effect of Age on Clinical and Morphological Characteristics in Patients With Brain Arteriovenous Malformation

Background and Purpose— The goal of this work was to determine the effect of age at initial presentation on clinical and morphological characteristics in patients with brain arteriovenous malformation (AVM).

Methods— The 542 consecutive patients from the prospective Columbia AVM database (mean±SD age, 34±15 years) were analyzed. Univariate statistical models were used to test the effect of age at initial presentation on clinical (AVM hemorrhage, seizures, headaches, neurological deficit, other/asymptomatic) and morphological (AVM size, venous drainage pattern, AVM brain location, concurrent arterial aneurysms) characteristics.

Results— Hemorrhage was the presenting symptom in 46% (n=247); 29% (n=155) presented with seizures, 13% (n=71) with headaches, 7% (n=36) with a neurological deficit, and 6% (n=33) without AVM-related symptoms. Increasing age correlated positively with intracranial hemorrhage ( P =0.001), focal neurological deficits ( P =0.007), infratentorial AVMs ( P <0.001), and concurrent arterial aneurysms ( P <0.001); an inverse correlation was found with seizures ( P <0.001), AVM size ( P =0.001), and lobar ( P <0.001), deep ( P =0.008), and borderzone ( P =0.014) location. No age differences were found for sex, headache, asymptomatic presentation, and venous drainage pattern.

Conclusions— Our data suggest a significant interaction of patient age and clinical and morphological AVM features and argue against uniform AVM characteristics across different age classes at initial presentation. In particular, AVM patients diagnosed at a higher age show a higher fraction of AVM hemorrhage and are more likely to harbor additional risk factors such as concurrent arterial aneurysms and small AVM diameter. Longitudinal population-based AVM data are necessary to confirm these findings.

Worker policing without genetic conflicts in a clonal ant

In group-living animals, mutual policing to suppress reproduction is an important mechanism in the resolution of conflict between selfish group members and the group as a whole. In societies of bees, ants, and wasps, policing against the production of males by other workers is expected when egg laying by workers decreases the average inclusive fitness of individual group members. This may result (i) from the relatedness of workers being lower to worker than to queen-derived males or (ii) from a lowered overall colony efficiency. Whereas good evidence exists for policing behavior caused by genetic conflicts, policing caused by efficiency factors has not been demonstrated. We investigated the regulation of reproduction in the ant Platythyrea punctata, a species in which colonies are clones because workers are capable of producing female offspring by thelytokous parthenogenesis. Reproductive conflicts resulting from differences in genetic relatedness are therefore not expected, but uncontrolled reproduction by all workers could lead to the destruction of sociality. Here we show that worker policing by aggressive attacks against additionally reproducing workers keeps the number of reproducing workers low. Furthermore, through experimental manipulation of the number of brood items per colony, we show that worker policing can enhance group efficiency.

A toxicity identification evaluation approach to studying estrogenic substances in hog manure and agricultural runoff

Spreading liquid manure on agricultural fields is a routine way of disposing of animal manure and optimizing the use of nutrients for crops. Limited studies suggest that these wastes may contain a variety of endocrine-disrupting compounds (EDCs) that may be released into aquatic environments through runoff. The purpose of this study was to apply a toxicity identification and evaluation approach to isolate and identify estrogenic compounds in hog manure. A recombinant yeast estrogen screen bioassay was used to detect estrogenicity of high-performance liquid chromatography--separated hog manure fractions. Further analytical analyses of the fractions and comparison to authentic standards resulted in the identification of the endogenous estrogens 17 beta-estradiol (E2) and estrone, and the phytoestrogen metabolite, equol. High levels of equol (6.9-16.6 ppm) were found to be present in manure that was stored for several months. The endocrine-disrupting potential of equol was characterized further by using fish hormone estrogen receptor (ER), sex hormone binding protein (SSBP), and goldfish androgen receptor (AR) radioligand binding assays. Equol was found to be approximately 1,000- and 200-fold less potent that E2 in competing for binding sites of the SSBP and ER, respectively. Equol's potency was 2,200-fold less than testosterone for the AR. Additional studies confirmed the presence of compounds with estrogenic activity in tile drain water after application of hog manure to an agriculture field. In this case, the contribution of equol to the total estrogenicity of the tile drain water was minimal relative to that of natural estrogens. Overall, this study indicates that further work is warranted to assess the impact that EDCs that originate from agricultural runoff may have on the ecology or physiology of exposed biota.

Changes in GAD67 mRNA expression evidenced by in situ hybridization in the brain of R6/2 transgenic mice

Huntington's disease is an autosomal dominant disorder with degeneration of medium size striatal neurones. As the disease evolves, other neuronal populations are also progressively affected. A transgenic mouse model of the disease (R6/2) that expresses exon 1 of the human Huntington gene with approximately 150 CAG repeats has been developed, but GABA concentrations are reported to be normal in the striatum of these animals. In the present study, we analysed the status of GABAergic systems by means of glutamic acid decarboxylase (GAD)67 mRNA in situ hybridization in the brain of R6/2 transgenic mice and wild-type littermates. We show that GAD67 expression is normal in the striatum, cerebellum and septum but decreased in the frontal cortex, parietal cortex, globus pallidus, entopeduncular nucleus and substantia nigra pars reticulata of R6/2 mice. These data, which may, in part, account for the behavioural changes seen in these animals, indicate that at 12.5 weeks of age the pathological features seen in the mice differ from those seen in humans with Huntington's disease.