Prevalence of genetic markers for thrombophilia in recurrent pregnancy loss

BACKGROUND: The genetic predispositions to venous thrombosis such as factor V Leiden (FVL) mutation (Arg 506 Gln), prothrombin (FII) gene mutation (G20210A), and mutation of the methylenetetrahydrofolate reductase (MTHFR) gene (C677T) have been reported to be associated with recurrent pregnancy loss. This paper examines the prevalence of markers for genetic thrombophilias in women with recurrent miscarriage. METHODS: The prevalence of FVL, FII G20210A and MTHFR C677T was compared in 108 women with three or more pregnancy losses either exclusively in the first trimester, or mixed first and second trimester losses, with the prevalence found in 82 fertile parous control women without miscarriages. Markers for the thrombophilias were assessed by PCR analysis. RESULTS: Twenty-three of the 108 patients (21.3%), had thrombophilia markers, which was similar to the proportion of patients in the control group (20.7%) with these markers. The prevalences of FVL and FII G20210A were lower in the study group than in the control group (3.7 versus 6.1% for FVL and 4.6 versus 6.1% for FII respectively); however, the difference was not statistically significant. In contrast, the prevalence of MTHFR C677T was higher in the study group than the control population (13 versus 8.5% respectively), but this difference was not statistically significant. There was no statistically significant prevalence of any particular thrombophilia in patients with previous first and second trimester pregnancy losses compared with patients with first trimester losses alone. CONCLUSION: Thrombophilia was not found to be associated with recurrent pregnancy loss.     

Murine leukemia virus in organs of senescence-prone and -resistant mouse strains

A series of inbred strains of mice have been developed that are either prone (SAMP) or resistant (SAMR) to accelerated senescence. All of these strains originated from an inadvertent cross or crosses between the AKR/J mouse strain and an unknown strain(s). The characteristics of the nine senescence-prone lines differ, with all strains showing generalized aspects of accelerated aging but with each line having a specific aging-related change that is emphasized, e.g. learning and memory deficits, osteoporosis and senile amyloidosis. The senescence-resistant strains have normal patterns of aging and do not show the specific aging-related changes seen in SAMP strains. The fact that AKR mice have high levels of endogenous, ecotropic murine leukemia virus (MuLV) prompted an examination of the expression levels of MuLV in SAM strains. Analysis of brain, spleen and thymus samples revealed that seven of nine SAMP strains had high levels of MuLV and contained the Emv11 provirus (previously termed Akv1) that encodes the predominant MuLV found in AKR mice. In contrast, none of the SAMR strains had Emv11 or significant amounts of virus. The current findings represent an initial step in determining the role of MuLV in the accelerated senescence seen in SAMP strains.     

Increased ferric iron content and iron-induced oxidative stress in the brains of scrapie-infected mice

Scrapie is a transmissible neurodegenerative disease of sheep and goats. The neuropathological changes include vacuolation, astrocytosis, the development of amyloid plaques in some instances, and neuronal loss. The mechanisms involved in neuronal cell death in scrapie are not known. Recently, we reported the presence of oxidative stress in the brains of scrapie-infected animals and suggested that this is the main mechanism that induces neuronal cell loss. It is known that oxidative stress induced by free radicals is associated with iron accumulation; this association led to an examination of the levels of iron (total iron, Fe²⁺ and Fe³⁺) in the brains of control and scrapie-infected mice by biochemical methods. In the scrapie-infected group, both the level of total iron and the Fe³⁺ level were significantly increased in cerebral cortex, striatum, and brainstem as compared to the values in the control group. A shift in the ratio of Fe²⁺/Fe³⁺ was observed in the same regions of infected mice. Additionally, in this scrapie model, we confirmed the presence of oxidative stress, as evidenced by the increase of free malondialdehyde. These results suggest that iron metabolism is changed and that iron-induced oxidative stress partly contributes to neurodegeneration in scrapie infection.     

EGFR gene copy number assessment from areas with highest EGFR expression predicts response to anti-EGFR therapy in colorectal cancer

Background:

Only 40–70% of metastatic colorectal cancers (mCRCs) with wild-type (WT) KRAS oncogene respond to anti-epidermal growth factor receptor (anti-EGFR) antibody treatment. EGFR amplification has been suggested as an additional marker to predict the response. However, improved methods for bringing the EGFR analysis into routine laboratory are needed.

Methods:

The material consisted of 80 patients with mCRC, 54 of them receiving anti-EGFR therapy. EGFR gene copy number (GCN) was analysed by automated silver in situ hybridisation (SISH). Immunohistochemical EGFR protein analysis was used to guide SISH assessment.

Results:

Clinical benefit was seen in 73% of high (⩾4.0) EGFR GCN patients, in comparison with 59% of KRAS WT patients. Only 20% of low EGFR GCN patients responded to therapy. A high EGFR GCN number associated with longer progression-free survival (P<0.0001) and overall survival (P=0.004). Together with KRAS analysis, EGFR GCN identified the responsive patients to anti-EGFR therapy more accurately than either test alone. The clinical benefit rate of KRAS WT/high EGFR GCN tumours was 82%.

Conclusion:

Our results show that automated EGFR SISH, in combination with KRAS mutation analysis, can be a useful and easily applicable technique in routine diagnostic practise for selecting patients for anti-EGFR therapy.     

Involvement of peptidylarginine deiminase-mediated post-translational citrullination in pathogenesis of sporadic Creutzfeldt-Jakob disease

Peptidylarginine deiminases (PADs)-mediated post-translational citrullination processes play key roles in protein functions and structural stability through the conversion of arginine to citrulline in the presence of excessive calcium concentrations. In brain, PAD2 is abundantly expressed and can be involved in citrullination in disease. Recently, we have reported pathological characterization of PAD2 and citrullinated proteins in scrapie-infected mice, but the implication of protein citrullination in the pathophysiology in human prion disease is not clear. In the present study, we explored the molecular and biological involvement of PAD2 and the pathogenesis of citrullinated proteins in frontal cortex of patients with sporadic Creutzfeldt-Jakob disease (sCJD). We found increased expression of PAD2 in reactive astrocytes that also contained increased levels of citrullinated proteins. In addition, PAD activity was significantly elevated in patients with sCJD compared to controls. From two-dimensional gel electrophoresis and MALDI-TOF mass analysis, we found various citrullinated candidates, including cytoskeletal and energy metabolism-associated proteins such as vimentin, glial fibrillary acidic protein, enolase, and phosphoglycerate kinase. Based on these findings, our investigations suggest that PAD2 activation and aberrant citrullinated proteins could play a role in pathogenesis and have value as a marker for the postmortem classification of neurodegenerative diseases.     

Diurnal H-reflex variation in mice

Mice exhibit diurnal variation in complex motor behaviors, but little is known about diurnal variation in simple spinally mediated functions. This study describes diurnal variation in the H-reflex (HR), a wholly spinal and largely monosynaptic reflex. Six mice were implanted with tibial nerve cuff electrodes and electrodes in the soleus and gastrocnemius muscles, for recording of ongoing and nerve-evoked electromyographic activity (EMG). Stimulation and recording were under computer control 24 h/day. During a 10-day recording period, HR amplitude varied throughout the day, usually being larger in the dark than in the light. This diurnal HR variation could not be attributed solely to differences in the net ongoing level of descending and segmental excitation to the spinal cord or stimulus intensity. HRs were larger in the dark than in the light even after restricting the evoked responses to subsets of trials having similar ongoing EMG and M-responses. The diurnal variation in the HR was out of phase with that reported previously for rats, but was in phase with that observed in monkeys. These data, supported by those in other species, suggest that the supraspinal control of the excitability of the HR pathway varies throughout the day in a species-specific pattern. This variation should be taken into account in experimental and clinical studies of spinal reflexes recorded at different times of day.     

Epidemiology of enterococci in a neonatal intensive care unit.

We performed an epidemiological investigation of a 62-bed neonatal intensive care unit in response to 2 infants with clinical cultures positive for vancomycin-resistant enterococci (VRE). Surveillance cultures detected 11 infants colonized with VRE. Surveillance triggered by even a single clinical culture positive for VRE may be justified in the neonatal intensive care unit, because a single culture result may represent a large hidden reservoir of VRE-colonized infants.     

The causes, prevention, and clinical management of broken endodontic rotary files

Complications can occur during many dental procedures. The prepared clinician responds by either correcting the problem during treatment, or, ideally, preventing the problem from occurring in the first place. In endodontic treatment separated rotary Ni-Ti files are a common procedural problem. Through understanding that the main causes of file breakage are cyclic fatigue and torsional stress, a dentist can best prevent this occurrence by using hand files before rotary files, creating a straight-line (glide path) access into a canal, and preflaring the coronal portion before using rotary files in the apical third of the canal. In addition, using an up and down motion with the electric slow-speed handpiece (not allowing the file to bind within the canal) will significantly reduce the incidence of file breakage. If a file does break, successful removal primarily depends on the location of the file in the canal rather than the specific technique employed for removal. A case does not necessarily fail if the separated file cannot be removed. The prognosis when file separation occurs can still be favorable, especially if care was taken to reduce the critical concentration of canal debris with hand instrumentation and chemical irrigation prior to rotary file insertion. In addition, the introduction of a new CS file design will help the dentist increase the chance of removing the file in the event of breakage.