61 research outputs found
FormaciΓ³n de imagen por microondas mediante agrupamientos lineales ortogonales
Capabilities of a microwave imaging system working in the air by using two crossed linear arrays are described. The analytic expressions of the focalization procedures are derived and resolution and available volume of reconstruction are discussed. Finally, some experimental images corresponding to two dielectric objects are also shown.Peer ReviewedPostprint (published version
Abnormal FHIT expression profiles in cervical intraepithelial neoplastic (CIN) lesions
Abnormal fragile histidine triad transcripts were found in 20β30% of CIN2/3 lesions and 11% of normal cervical biopsies by RTβPCR. Bi-allelic loss of the fragile histidine triad gene and the loss of fragile histidine triad protein expression detectable by immunochemical staining with a polyclonal fragile histidine triad specific antibody was rare. The genomic changes showed no association with the presence of human papillomavirus types which carry high risk for cervical cancer (high risk human papillomavirus) as assessed by a type-specific multiplex PCR. The presence of abnormal fragile histidine triad transcripts in a subset of CIN2/3 lesions with no high risk human papillomavirus suggests that this could be an independent risk factor associated with an alternative carcinogenic pathway
Specific induction of pp125 focal adhesion kinase in human breast cancer
The pp125 focal adhesion kinase (FAK) is involved in integrin-mediated cell signalling and overexpressed in a variety of solid tumours. Focal adhesion kinase expression has been correlated to invasion and metastasis, but the data on breast cancer are inconclusive. We analysed FAK mRNA, protein levels and expression patterns in primary breast cancer and normal breast tissue. FAK expression on the functional protein level and mRNA was determined in 55 matched pairs of breast cancer and corresponding normal tissue by Western blot, immunohistochemistry and RTβPCR. Using a score ranging from 0 to +5 for Western blots, we determined in normal breast tissue a score of 1.51Β±0.84 (meanΒ±standard deviation), which was strongly induced to 2.91 (Β±1.22) in breast cancers (P<0.001). Overall, 45 out of 55 tissue pairs (81.8%) showed this upregulation of FAK protein in tumours in comparison to normal tissue. Immunohistochemistry confirmed these findings with a significant higher score for tumours vs physiological tissue (1.0Β±0.63 vs 2.27Β±0.91; P=0.001). Interestingly, no overall significant difference in the mRNA levels (P=0.359) was observed. In conclusion, expression levels of the FAK protein are specifically upregulated in breast cancer in comparison to matched normal breast tissue supporting its pivotal role in neoplastic signal transduction and representing a potential marker for malignant transformation
Seroepidemiology of Human Polyomaviruses
In addition to the previously characterized viruses BK and JC, three new human polyomaviruses (Pys) have been recently identified: KIV, WUV, and Merkel Cell Py (MCV). Using an ELISA employing recombinant VP1 capsid proteins, we have determined the seroprevalence of KIV, WUV, and MCV, along with BKV and JCV, and the monkey viruses SV40 and LPV. Soluble VP1 proteins were used to assess crossreactivity between viruses. We found the seroprevalence (+/β 1%) in healthy adult blood donors (1501) was SV40 (9%), BKV (82%), JCV (39%), LPV (15%), KIV (55%), WUV (69%), MCV strain 350 (25%), and MCV strain 339 (42%). Competition assays detected no sero-crossreactivity between the VP1 proteins of LPV or MCV or between WUV and KIV. There was considerable sero-crossreactivity between SV40 and BKV, and to a lesser extent, between SV40 and JCV VP1 proteins. After correcting for crossreactivity, the SV40 seroprevalence was βΌ2%. The seroprevalence in children under 21 years of age (nβ=β721) for all Pys was similar to that of the adult population, suggesting that primary exposure to these viruses likely occurs in childhood
Human Papillomaviruses Activate the ATM DNA Damage Pathway for Viral Genome Amplification upon Differentiation
Human papillomaviruses (HPV) are the causative agents of cervical cancers. The infectious HPV life cycle is closely linked to the differentiation state of the host epithelia, with viral genome amplification, late gene expression and virion production restricted to suprabasal cells. The E6 and E7 proteins provide an environment conducive to DNA synthesis upon differentiation, but little is known concerning the mechanisms that regulate productive viral genome amplification. Using keratinocytes that stably maintain HPV-31 episomes, and chemical inhibitors, we demonstrate that viral proteins activate the ATM DNA damage response in differentiating cells, as indicated by phosphorylation of CHK2, BRCA1 and NBS1. This activation is necessary for viral genome amplification, as well as for formation of viral replication foci. In contrast, inhibition of ATM kinase activity in undifferentiated keratinocytes had no effect on the stable maintenance of viral genomes. Previous studies have shown that HPVs induce low levels of caspase 3/7 activation upon differentiation and that this is important for cleavage of the E1 replication protein and genome amplification. Our studies demonstrate that caspase cleavage is induced upon differentiation of HPV positive cells through the action of the DNA damage protein kinase CHK2, which may be activated as a result of E7 binding to the ATM kinase. These findings identify a major regulatory mechanism responsible for productive HPV replication in differentiating cells. Our results have potential implications for the development of anti-viral therapies to treat HPV infections
Inhaler technique : facts and fantasies. A view from the Aerosol Drug Management Improvement Team (ADMIT)
Health professionals tasked with advising patients with asthma and chronic obstructive pulmonary disease (COPD) how to use inhaler devices properly and what to do about unwanted effects will be aware of a variety of commonly held precepts. The evidence for many of these is, however, lacking or old and therefore in need of re-examination. Few would disagree that facilitating and encouraging regular and proper use of inhaler devices for the treatment of asthma and COPD is critical for successful outcomes. It seems logical that the abandonment of unnecessary or ill-founded practices forms an integral part of this process: the use of inhalers is bewildering enough, particularly with regular introduction of new drugs, devices and ancillary equipment, without unnecessary and pointless adages. We review the evidence, or lack thereof, underlying ten items of inhaler 'lore' commonly passed on by health professionals to each other and thence to patients. The exercise is intended as a pragmatic, evidence-informed review by a group of clinicians with appropriate experience. It is not intended to be an exhaustive review of the literature; rather, we aim to stimulate debate, and to encourage researchers to challenge some of these ideas and to provide new, updated evidence on which to base relevant, meaningful advice in the future. The discussion on each item is followed by a formal, expert opinion by members of the ADMIT Working Group
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