Use of polyethylene glycol coatings for optical fibre humidity sensing

Humidity induced change in the refractive index and thickness of the polyethylene glycol (PEG) coatings are in situ investigated for a range from 10 to 95%, using an optical waveguide spectroscopic technique. It is experimentally demonstrated that, upon humidity change, the optical and swelling characteristics of the PEG coatings can be employed to build a plastic fibre optic humidity sensor. The sensing mechanism is based on the humidity induced change in the refractive index of the PEG film, which is directly coated onto a polished segment of a plastic optical fibre with dip-coating method. It is observed that PEG, which is a highly hydrophilic material, shows no monotonic linear response to humidity but gives different characteristics for various ranges of humidity levels both in index of refraction and in thickness. It undergoes a physical phase change from a semi-crystal line structure to a gel one at around 80% relative humidity. At this phase change point, a drastic decrease occurs in the index of refraction as well as a drastic increase in the swelling of the PEG film. In addition, PEG coatings are hydrogenated in a vacuum chamber. It is observed that the hydrogen has a preventing effect on the humidity induced phase change in PEG coatings. Finally, the possibility of using PEG coatings in construction of a real plastic fibre optic humidity sensor is discussed. (C) 2008 The Optical Society of Japan

p27(Kip1 )is expressed in proliferating cells in its form phosphorylated on threonine 187

BACKGROUND: G1/S cell cycle progression requires p27(Kip1 )(p27) proteolysis, which is triggered by its phosphorylation on threonine (Thr) 187. Since its levels are abundant in quiescent and scarce in cycling cells, p27 is an approved marker for quiescent cells, extensively used in histopathology and cancer research. METHODS: However here we showed that by using a specific phosphorylation site (pThr187) antibody, p27 is detectable also in proliferative compartments of normal, dysplastic and neoplastic tissues. RESULTS: In fact, whereas un-phosphorylated p27 and MIB-1 showed a significant inverse correlation (Spearman R = -0.55; p < 0,001), pThr187-p27 was positively and significantly correlated with MIB-1 expression (Spearman R = 0.88; p < 0,001). Thus proliferating cells only stain for pThr187-p27, whereas they are un-reactive with the regular p27 antibodies. However increasing the sensitivity of the immunocytochemistry (ICH) by the use of an ultra sensitive detection system based on tiramide signal amplification, simultaneous expression and colocalisation of both forms of p27 was shown in proliferating compartments nuclei by double immunofluorescence and laser scanning confocal microscopy studies. CONCLUSION: Overall, our data suggest that p27 expression also occurs in proliferating cells compartments and the combined use of both regular and phospho- p27 antibodies is suggested

Prognostic value of p27(Kip1 )expression in Basaloid Squamous Cell Carcinoma of the larynx

BACKGROUND: Very few reports have investigated the role of cell cycle regulators as biomarkers in Basaloid Squamous Cell Carcinoma (BSCC) of the larynx, a definite morphologic, uncommon, very aggressive variant of squamous cell carcinoma. Lower expression of Ki67/Mib-1, a proliferation marker highly expressed in the majority of tumours, and p53, a tumour suppressor protein that can induce an arrest of the G1-S transition, was related to a better prognosis in laryngeal BSCC. In the head and neck, p27(kip1), a member of the Cip1/Kip1 family of cyclin-dependent kinase inhibitors, has emerged as an independent prognostic factor, able to identify low-expressing tumours with unfavourable course. Up to date the role of this protein was never studied in BSCC. Aim of our study was to investigate the potential prognostic value of p27(kip1 )levels and their correlation with Ki67/Mib-1 and p53 expression in BSCC of the larynx. METHODS: The retrospective study group consisted of 15 male and 1 female patients, affected by laryngeal BSCC, ranging in age from 44 to 69 years (mean 58). The tumour originated from the supraglottis in thirtheen cases and from the glottis in the remaining three. Ten patients had metastatic cervical lymph nodes at presentation and were classified as N+. Post surgical stage was IV in four patients, III in nine, II in two cases and I in the remaining one. Follow-up ranged from a minimum of 5 months up to 9 years. Paraffin-embedded tissue sections of each laryngeal tumour were analyzed for p27(kip), Ki67/Mib-1 and p53 expression by immunohistochemistry. RESULTS: The immunohistochemical study showed p27(kip1 )expression in 40% of the patients with no evidence of disease (NED) and in none (0%) of the patients dead of disease (DOD), whilst p53 was expressed in 60% of patients in NED status and in 90% of patients in DOD status. Ki67/Mib-1 was positive in 80% of NED patients and in 100% of DOD patients. At multivariate analysis, performed by means of Discriminant analysis, low levels of p27(kip1 )expression significantly correlated with poor prognosis (P < 0.05). CONCLUSION: p27(kip1 )protein has been shown to be a significant independent prognostic factor in laryngeal SCC. In our series of laryngeal BSCC the resulting data seem to confirm the clinical prognostic relevance of p27(kip1 )low expression, which directly correlated with biological aggressiveness and consequent shortened survival

GALLSTONE RECURRENCE AFTER SHOCK-WAVE THERAPY

Fifty-three patients with complete clearance of all gallstone fragments after combined extracorporeal shock wave lithotripsy (ESWL) oral litholytic therapy were included in the study. Eight patients had recurrence of gallstones within the first year at follow-up evaluation. The rate of gallstone recurrence was 15.2 percent within the first year. Four of these eight patients reported biliary pain, the other four remained asymptomatic. The incidence of gallstone recurrence was high in patients who had multiple stones before ESWL treatment (p<0.05). Age above 60 years was also associated with a higher rate of gallstone recurrence (p<0.05)

The fate of alloplastic materials placed under a burn scar: an experimental study

The behaviour, under burn scars , of three different alloplastic materials, silicone, Medpor and Proplast, was compared in an animal model. A standard burn wound was created in rats, and 3 months later silicone, medpor and proplast alloplasts were placed under the burn scar. The rats were followed for another 3 months and ulceration and/or alloplast exposure rates were evaluated. At the end of this period specimens were examined histologically for the thickness of the fibrous capsule around the implant, thickness of the overlying tissue, tissue ingrowth and vascularization of the implants. Ulceration and exposure occurred in 2 of the 12 Medpor, 2 of the 12 Proplast and none of the 12 silicone implants. Fibrous capsule was significantly thicker around the silicone implants. Tissue ingrowth and vascularization were most prominent in Medpor implants while thickness of the overlying tissue was maximum in Proplast implants. These findings suggest that complications with silicone implants may be less than with other porous implants when used under burn scarred tissue. (C) 1997 Elsevier Science Ltd for ISBI

Icodextrin and Seprafilm((R)) do not interfere with colonic anastomosis in rats

Background: Physical barriers and instilled solutions have been studied to prevent intra-abdominal adhesions. However, undesirable side effects of these substances on the healing of intestinal anastomoses may limit their use. This study was designed to compare the effects of antiadhesives on the healing of colonic anastomosis in rats. Methods: Sixty female Sprague-Dawley rats were divided into 3 groups of 20. The animals received isotonic saline and 7.5% icodextrin, intraperitoneally after standard left colonic anastomosis. In group 3, Seprafilm((R)) was wrapped around the anastomosis and also laid over the abdominal viscera. Half of the animals from each group were killed on postoperative day (POD) 4 and the remaining half on POD 21. Adhesion scoring, bursting pressure and tissue hydroxyproline measurements and histopathological assessment were performed. Results: Mean hydroxyproline levels were significantly higher in groups receiving icodextrin and Seprafilm compared with the control group, whereas mean bursting pressures were significantly higher in the group that received icodextrin p < 0.05). Intraperitoneal administration of icodextrin resulted in significant reduction of adhesion formation on POD 21 ( p < 0.05). Conclusions: Seprafilm does not prevent formation of adhesions as much as icodextrin does, but its effect on the healing of colonic anastomoses is similar. Copyright (c) 2007 S. Karger AG, Basel