Usefulness and influence of age of a novel rapid monoclonal enzyme immunoassay stool antigen for the diagnosis of Helicobacter pylori infection in children

The synergistic potential of ceftazidime plus amikacin or levofloxacin was assessed against 61 Pseudomonas aeruginosa isolates with variable susceptibility patterns to the 3 antibiotics. A checkerboard broth method and a disk diffusion method were used and compared. The latter, also easy to perform as a triple-disk assay, could be a helpful laboratory screening tool for drug synergism to drive possible combination treatments.     

High frequency and allele‐specific differences of BRCA1 founder mutations in breast cancer and ovarian cancer patients from Belarus

Bogdanova NV, Antonenkova NN, Rogov YI, Karstens JH, Hillemanns P, Dörk T. High frequency and allele‐specific differences of BRCA1 founder mutations in breast cancer and ovarian cancer patients from Belarus. Breast cancer and ovarian cancer are common malignancies in Belarus accounting for about 3500 and 800 new cases per year, respectively. For breast cancer, the rates and age of onset appear to vary significantly in regions differentially affected by the Chernobyl accident. We assessed the frequency and distribution of three BRCA1 founder mutations 5382insC, 4153delA and Cys61Gly in two hospital‐based series of 1945 unselected breast cancer patients and of 201 unselected ovarian cancer patients from Belarus as well as in 1019 healthy control females from the same population. Any of these mutations were identified in 4.4% of the breast cancer patients, 26.4% of the ovarian cancer patients and 0.5% of the controls. In the breast cancer patients, BRCA1 mutations were strongly associated with earlier age at diagnosis, with oestrogen receptor (ER) negative tumours and with a first‐degree family history of breast cancer, although only 35% of the identified BRCA1 mutation carriers had such a family history. There were no marked differences in the regional distribution of BRCA1 mutations, so that the significant differences in age at diagnosis and family history of breast cancer patients from areas afflicted by the Chernobyl accident could not be explained by BRCA1. We next observed a higher impact and a shifted mutational spectrum of BRCA1 in the series of Byelorussian ovarian cancer patients where the three founder mutations accounted for 26.4% (53/201). While the Cys61Gly mutation appeared underrepresented in ovarian cancer as compared with breast cancer cases from the same population (p = 0.01), the 4153delA mutation made a higher contribution to ovarian cancer than to breast cancer (p < 0.01). BRCA1 mutations were significantly enriched among ovarian cancer cases with a first‐degree family history of breast or ovarian cancer, whereas the median age at ovarian cancer diagnosis was not different between mutation carriers and non‐carriers. Taken together, these results identify three BRCA1 founder mutations as key components of inherited breast and ovarian cancer susceptibility in Belarus and might have implications for cancer prevention, treatment and genetic counselling in this population.     

Habituation of auditory evoked potentials in intracranial and extracranial recordings

Effects of stimulus repetition are investigated in short-term habituation experiments. In these experiments, trains of stimuli are applied with longer intervals of no stimulation between the trains. In scalp recordings, an amplitude and latency decrease of the auditory N100 is usually observed at the beginning of the train. This contrasts to a recent finding with intracranial recordings, exhibiting an effect on N100 amplitude, but not on its latency. In the current study, P50 and N100 were simultaneously recorded intra- and extracranially in epilepsy patients. The amplitudes of P50 and N100 decreased in both recordings, whereas the P50 latency was not significantly affected. A latency decrease was revealed for the extracranially recorded N100, but not for the intracranial N100. This dissociation between the intracranial and scalp recordings might be explained by a different sensitivity of the two measurements for N100 generators.     

Sensory gating-out and gating-in in normal and schizophrenic participants

In contrast to sensory gating, the brain's ability to re-respond to relevant stimuli and the potential differences between healthy and schizophrenic participants have not been studied in great detail. Here, we explore what auditory paradigms are useful to measure this re-responding ability. Evoked potentials (EPs) were obtained from the Cz channel using 3 paired stimulus paradigms (pairs with equal stimuli {PE}, the second stimulus being lower {PL} or higher {PH} in frequency) and 2 short-train paradigms in which 5 identical stimuli were followed by a lower frequency stimulus (train lower {TL}) or higher frequency stimulus (train higher {TH}). Data were collected from 17 healthy control participants (NC) and 17 age and gender-matched patients with schizophrenia (SZ). Up to 4 data sets obtained on 4 different days were available for each participant. Ensemble averages were computed for each session, from which the P50, N100, and P200 latencies and amplitudes were obtained. No significant differences in amplitude or latency of the various EP components were found between the responses to the second stimulus obtained with the 5 paradigms. Neither did the responses to the fifth and sixth stimuli differ for the TL and TH paradigm, with the exception of the N100 latency of the fifth stimulus, which was longer for TH than TL for NC. Healthy participants had larger amplitudes and shorter latencies than the patients with schizophrenia for the responses to the first stimuli, with the latency differences continuing for the fifth and sixth response. Also, the amplitude and latency of the first response was larger than for the second response in both populations. In conclusion, none of the paradigms studied here, with the employed parameters, are useful to measure the re-responding ability of the brain. Also, the shorter latencies for the repeated stimulus suggest that the neural mechanism underlying attenuation of repeated stimuli is of a facilitating nature.