Diabetes mellitus effect on rat corneal dielectric properties

In the course of the study, we carried out a dielectric examination to determine the effect of diabetes mellitus on the rat corneal function. Measurements were performed over the frequency range of 500 Hz-100 kHz in air and at the temperatures from 25 to 150°C. The frequency dependencies of the loss tangent for the healthy and the diabetic cornea exhibit two peaks at 2 kHz and 16 kHz in the α-dispersion region. The amplitude of these both peaks is smaller for the diabetic cornea than that for the healthy one. The temperature dependencies of the loss tangent for the healthy and the diabetic cornea reveal β-relaxation in the range of 30-70°C and 50-90°C, respectively. The present study exhibits that the dielectric spectroscopy is useful in detection of the effect of diabetes mellitus on the corneal molecular behavior.

Implications of the alpha dispersion for studies on interaction of tobacco smoke--corneal tissue

In this work, we have carried out a dielectric study to determine the effect of tobacco smoke on the rat corneal function. Measurements were performed over the frequency range of 500 Hz-100 kHz in air and at the temperature of 35°C. The frequency dependencies of the loss tangent for both healthy and smoky cornea exhibit two peaks with different width occurring as a narrow at 2 kHz and a broad at around 16 kHz. The distribution parameter α at 2 kHz has a value of about 0.3, which increases to 0.6 at 16 kHz. The magnitude of the permittivity decrement at 2 and 16 kHz is about two and four times higher, respectively, for the smoky cornea than that for the healthy one. These dielectric studies indicate that the present method is useful in detection of the effect of tobacco smoke exposure on the corneal behavior.

Supplementation with L-arginine does not influence arterial blood pressure in healthy people: a randomized, double blind, trial

BACKGROUND AND OBJECTIVES

It cannot be excluded that supplementation with L-arginine, by improving function of endothelium and hypotensive effect, can be advantegeous in prevention of cardiovascular diseases in healthy people. However, reports about hypotensive effect of L-arginine in healthy people are unclear. Moreover, no research including ambulatory blood pressure measurement (ABPM) has been conducted so far. Therefore, the aim of our study was to show if 4-week supplementation of healthy people with L-arginine influences blood pressure measured with ABPM.

MATERIALS AND METHODS

The study was carried out on 19 healthy people randomized to 6 g/24-hour, 12 g/24-hours of L-arginine or placebo. ABPM was carried out 4 times: before randomization, after 2 and 4 weeks of supplementation and 2 weeks after finishing supplementation.

RESULTS

It was found that 4 weeks of supplementation of healthy people with L-arginine (6 or 12 g/24-hour) led to nonsignificant decrease of systolic and diastolic blood pressure; the decrease was greater during night.

CONCLUSION

These findings showed that supplementation with L-arginine is not necessarily advantageous in healthy people.

Impaired nucleotide excision repair pathway as a possible factor in pathogenesis of head and neck cancer

Tobacco smoking is one of the major risk factors in pathogenesis of head and neck squamous cell carcinomas (HNSCC). Many of the chemical compounds present in tobacco are well-known carcinogens which form adducts with DNA. Cells remove these adducts mainly by the nucleotide excision repair pathway (NER). NER also eliminates a broad spectrum of pyrimidine dimers (CPD) and photo-products (6-4PP) induced by UV-radiation or DNA cross-links after cisplatin anti-cancer treatment. In this study DNA damage and repair was examined in peripheral blood lymphocytes obtained from 20 HNSCC patients and 20 healthy controls as well as HTB-43 larynx and SSC-25 tongue cancer cell lines. DNA repair kinetics in the examined cells after cisplatin or UV-radiation treatment were investigated using alkaline comet assay during 240min of post-treatment incubation. MTT assay was used to analyse cell viability and the Annexin V-FITC kit specific for kinase-3 was employed to determine apoptosis after treating the cells with UV-radiation at dose range from 0.5 to 60J/m(2). NER capability was assessed in vitro with cell extracts by the use of a bacterial plasmid irradiated with UV-light as a substrate for the repair. The results show that lymphocytes from HNSCC patients and HTB-43 or SSC-25 cancer cells were more sensitive to genotoxic treatment with UV-radiation and displayed impaired DNA repair. Also evidenced was a higher rate of apoptosis induction after UV-radiation treatment of lymphocytes from the HNSCC patients and the HTB-43 cancer cells than after treatment of those from healthy donors. Finally, our results showed that there was a significant decrease in NER capacity in HTB-43 or SSC-25 cancer cells as well as in peripheral blood lymphocytes of HNSCC patients compared to controls. In conclusion, we suggest that the impaired NER pathway might be a critical factor in pathogenesis of head and neck cancer.

Intermodal interferometer for strain and temperature sensing fabricated in birefringent boron doped microstructured fiber

We present a compact in-line fiber interferometric sensor fabricated in a boron doped two-mode highly birefringent microstructured fiber using a CO(2) laser. The intermodal interference arises at the fiber output due to coupling between the fundamental and the first order modes occurring at two fiber tapers distant by a few millimeters. The visibility of intermodal interference fringes is modulated by a polarimetric differential signal and varies in response to measurand changes. The proposed interferometer was tested for measurements of the strain and temperature, respectively, in the range of 20-700 °C and 0-17 mstrain. The sensitivity coefficients corresponding to fringe displacement and contrast variations are equal respectively for strain -2.51 nm/mstrain and -0.0256 1/mstrain and for temperature 16.7 pm/°C and 5.74×10(-5) 1/°C. This allows for simultaneous measurements of the two parameters by interrogation of the visibility and the displacement of interference fringes.

Polymorphisms of the DNA repair genes XRCC1 and ERCC4 are not associated with smoking- and drinking-dependent larynx cancer in a Polish population

BACKGROUND

Tobacco smoking and alcohol drinking generate oxidative DNA damage and may contribute to larynx carcinogenesis. The X-ray repair cross complementing 1 (XRCC1) and excision repair cross-complementing rodent repair deficiency, complementation group 4 (ERCC4(XPF)) genes are important components of DNA excision repair systems, which repair DNA damage induced by various factors, including tobacco smoking and alcohol.

AIM

To investigate the association between the genotypes of the XRCC1-Arg399Gln (rs25487) and ERCC4-Arg415Gln (rs1800067) polymorphisms and smoking- and drinking-related larynx cancer in a Polish population.

METHODS

The polymorphisms were determined by PCR-RFLP method in 253 patients with squamous cell carcinoma of the larynx and 253 sex- and age-matched controls.

RESULTS

We did not find any association between the investigated polymorphisms and larynx carcinoma, dependent on either smoking or drinking status. No association was found between these polymorphisms and larynx cancer grade, stage or age at diagnosis.

CONCLUSIONS

The results indicated that Arg399Gln polymorphism of XRCC1 gene and Arg415Gln polymorphism of ERCC4 gene may not be associated with smoking- and drinking-related larynx cancer in Polish population.

Highly birefringent microstructured fibers with enhanced sensitivity to hydrostatic pressure

We designed, manufactured and characterized two birefringent microstructured fibers that feature a 5-fold increase in polarimetric sensitivity to hydrostatic pressure compared to the earlier reported values for microstructured fibers. We demonstrate a good agreement between the finite element simulations and the experimental values for the polarimetric sensitivity to pressure and to temperature. The sensitivity to hydrostatic pressure has a negative sign and exceeds -43 rad/MPa x m at 1.55 microm for both fibers. In combination with the very low sensitivity to temperature, this makes our fibers the candidates of choice for the development of microstructured fiber based hydrostatic pressure measurement systems.

DNA double strand breaks repair and apoptosis induction in peripheral blood lymphocytes of head and neck cancer patients

AIM

To evaluate the generation and repair of DNA double strand breaks (DSBs) as a critical factors that define the efficiency of radiation therapy of cancer patients.

METHODS

Peripheral blood lymphocytes obtained from 18 patients with head and neck squamous cell carcinoma (HNSCC) and 18 healthy donors were studied. The efficiency of DSBs repair after genotoxic treatment with hydrogen peroxide and gamma-radiation were examined by neutral comet assay. MTT assay was used for cell viability analysis and Annexin V-FITC kit specific for kinase-3 was employed to determine apoptosis.

RESULTS

Lymphocytes from HNSCC patients were sensitive to genotoxic treatment and displayed impaired DSBs repair. Finally, as a consequence of this finding we have evidenced higher rate of apoptosis induction after gamma-radiation treatment of lymphocytes from HNSCC patients than those from healthy controls.

CONCLUSIONS

DSBs repair and increased apoptosis in cells of patients with head and neck cancer is relevant for efficient therapy of HNSCC.

Nonlinear control of soliton pulse delay with asymmetric dual-core photonic crystal fibers

Dual-core photonic crystal fiber nonlinear couplers permit the achievement of distortion-free power-controlled delay of picosecond pulses. The stable control of pulse time delay is achievable by means of resonance soliton solutions.

Polymorphisms of the DNA base excision repair gene MUTYH in head and neck cancer

BACKGROUND

Head and neck squamous cell carcinomas (HNSCC) comprise about 6% of all malignant neoplasms. The major risk factors of -HNSCC are smoking and alcohol consumption. Genetic polymorphisms of DNA repair enzymes may lead to genetic instability and carcinogenesis. MUTYH gene encodes a DNA glycosylase that can initiate the base excision repair (BER) pathway and prevent G:C > T:A transversion by excising adenine mispaired with 8-hydroxyguanine produced by reactive oxygen species (ROS).

AIM

to perform a case-control study to test the association between polymorphism in the MUTYH gene: Tyr165Cys and head and neck cancer risk progression.

METHODS

Genotypes were determined in DNA from peripheral blood lymphocytes of 193 patients (among them 97 subjects with precancerous hyperplastic laryngeal lesions and 96 subjects with head and neck cancer) and 140 age, sex and ethnic-matched cancer-free controls by tetra-primer amplification refractory mutation system PCR (T-ARMS-PCR).

RESULTS

We found an association between head and neck cancer risk and the Tyr165Tyr variant of the MUTYH gene (OR 2.18; 95% CI 1.19-3.97). For Tyr165Tyr genotype we also observed positive correlation with cancer progression assessed by tumor size (OR 4.56; 95% CI 1.60-12.95). We did not observe any correlation between Tyr165Cys polymorphism of MUTYH gene and precancerous hyperplastic laryngeal lesions risk.

CONCLUSION

The Tyr165Tyr polymorphic variant of the MUTYH gene may be associated with head and neck cancer in Polish population.

Birefringence in microstructure fiber with elliptical GeO2 highly doped inclusion in the core

We studied both numerically and experimentally a birefringence in a microstructure fiber with elliptical inclusion highly doped with GeO(2). We demonstrate that such inclusion increases the phase modal birefringence and modifies its dispersion in the short wavelength range, thus causing that group birefringence crosses zero value at a certain wavelength. Moreover, we numerically analyzed different factors contributing to the overall fiber birefringence, including geometrical birefringence induced by holes distribution and ellipticity of the inclusion as well as stress birefringence associated with thermal shrinkage of the doped glass.

Hand exposure to ionising radiation of nuclear medicine workers

The specific nature of work in nuclear medicine departments involves the use of isotopes and handling procedures, which contribute to the considerable value of an equivalent dose received, in particular, by the fingertips. Standard nuclear medicine department uses ring dosemeters placed usually at the base of the middle finger. The main aim of the study was to find out whether a relationship exists between the doses recorded by thermoluminescent detectors placed at various locations on the radiopharmacists' hands and the doses recorded by the ring detectors, and to determine the character of that relationship. The correction factor represents a correction value to be used to calculate the doses which might be received by locations on the hand from the dose recorded by the ring dosemeter. The dose recorded by the ring dosemeter is on the average five times lower than that received by the fingertips of thumb, index and middle fingers.

Experimental investigations of bending loss oscillations in large mode area photonic crystal fibers

We demonstrate experimentally that bending loss in large mode area photonic crystal fibers oscillates with wavelength. To do so we carried out loss measurements for different fiber bend radii and for different angular orientations. These results confirm the oscillatory behavior of bending loss vs. wavelength as predicted recently by numerical analysis [J. Olszewski et al., Opt. Express 13, 6015 (2005)]. We also found good agreement between our measurement results and our simulations relying on a finite element method with perfectly matched layers and an equivalent index model.

PCR approach based on the esyn1 gene for the detection of potential enniatin-producing Fusarium species

Fusarium head blight (FHB) is a disease of small-grain cereals and corn caused by a complex of fungal species of the genus Fusarium. The disease reduces the yield and quality of seeds and results in the accumulation of various mycotoxins which cause a variety of toxic effects on humans and livestock. Beauvericin (BEA) and enniatins (ENs) are a group of toxins with antimicrobial, insecticidal and phytotoxic activities produced mainly by F. avenaceum, F. poae and F. tricinctum. In this study, primer sets were designed that were targeted to esyn1 gene homologs encoding multifunctional enzyme enniatin synthetase. Primers used in multiplex PCR amplified products from the FHB species reported to produce (ENs) and/or BEA. The use of the marker developed on asymptomatic wheat seed samples originating from Northern and Southern Poland demonstrated that all samples were positive for the presence of potential enniatin-producing Fusarium species.

Sentinel node biopsy in patients with breast cancer—evaluation of exposureto radiation of medical staff

AIM

To measure the absorbed doses of radiation to hands of medical staff performing sentinel node biopsy in breast cancer patients.

METHODS

The study was conducted in 2004, during sentinel node biopsies in 13 breast cancer patients (T1/T2N0). Sentinel nodes were identified with the use of combined radiotracer/blue dye technique (lymphoscintigraphy--99mTc on albumin carrier, surgery after 24 h; blue dye; intraoperative detection of gamma radiation). Highly sensitive thermoluminescent dosimeters (TLD) made of LiF were used to assess the absorbed doses of radiation during the procedure. During lymphoscintigraphy and during surgical procedure a total of 57 TLDs was placed on different parts of hands of medical staff.

RESULTS

Maximal dose recorded during lymphoscintigraphy by TLDs placed on the hands of the physician injecting the radiotracer was 164 microSv. Mean recorded doses were higher for non-dominant hand, especially for distal parts of the index finger, third finger and thumb. During the surgical procedure, TLDs placed on the hands of medical staff recorded much lower doses of radiation than during lymphoscintigraphy. The highest dose was recorded by TLD placed on the pulp of the dominant hand index finger (22 microSv) of the operating surgeon. Mean doses recorded by TLDs placed on the hands of the operating surgeon ranged from 2 to 8 microSv. The absorbed dose of radiation to hands of the scrub nurse was similar to that absorbed to hands of the operating surgeon.

CONCLUSION

The maximum recorded dose during sentinel node biopsy in this study was 2200 times smaller than current 1-year dose limit.

Comparative assessment of aluminum and lead concentrations in serum and tissue bioptates in patients with laryngeal papilloma or cancer

A comparative assessment of toxic element concentrations in serum and tissue bioptates in patients with laryngeal papilloma or cancer was performed. Examinations were conducted in 60 patients (40 men and 20 women) aged 20-88 years (average 59 +/- 05). Patients were divided into 3 groups; 20 patients with laryngeal papilloma were in group I, 20 with laryngeal cancer were in group II, and 20 with deviated nasal septums were included as a control group (III). Diagnosis of laryngeal papilloma (removed by direct microlaryngoscopy--Kleinsasser method) and laryngeal cancer (removed by the Rethi method) was histopatologically confirmed in patients from groups I and II, respectively. Patients in the control group received functional surgery to repair deviated nasal septums. Serum and tissue samples were obtained from all patients before surgery. Aluminum and lead concentrations were analysed by inductively coupled plasma atomic emission spectrometry (ICP-AES) using a Spectroflame M spectrometer. The considerable rise of aluminum and lead concentration in tissue bioptates and aluminum in serum in groups I and II in comparison to the control group suggests that these elements may play a significant part in the aetiology and development of precancerous lesions and laryngeal cancers. Measuring toxic chemical element concentrations in tissue bioptates can be useful in the diagnosis and estimation of development of precancerous lesions of the larynx as well as laryngeal cancer. Toxic elements concentration may play a significant role in carcinogenesis and may determine trends in cancer aetiology.

Effect of coupling between fundamental and cladding modes on bending losses in photonic crystal fibers

The paper presents a fully vectorial analysis of bending losses in photonic crystal fibers employing edge/nodal hybrid elements and perfectly matched layers boundary conditions. The oscillatory character of losses vs. both the wavelength and the bending radius has been demonstrated. The shown oscillations originate from the coupling between the fundamental mode guided in the core and the gallery of cladding modes arising due to light reflection from the boundary between solid and holey part of the cladding.

Experimental and theoretical investigations of birefringent holey fibers with a triple defect

We have manufactured and characterized a birefringent holey fiber of a new construction. The birefringence in this fiber is induced by the highly elliptical shape of the core, which consists of a triple defect in a hexagonal structure. Using a hybrid edge-nodal finite-element method, we calculated the spectral dependence of phase and group modal birefringence for spatial modes E11 and E21 in idealized and in real fiber, whose geometry we determined by using a scanning-electron microscope. Results of our calculations show that technological imperfections significantly affect the fiber's birefringence. Normalized cutoff wavelengths for higher-order modes relative to the filling factor were also determined for the idealized structure. We observed a significant disagreement between theoretical and experimental values of cutoff wavelengths, which was attributed to high confinement losses near the cutoff condition. We also measured the spectral dependence of the phase and the group modal birefringence for spatial modes E11 and E21. The measured parameters showed good agreement with the results of modeling.

Qualitative and quantitative studies in electron microscopy on influence of experimental ischemia of the vertebral arteries on the outer hair cells function in guinea pigs

Histological studies were performed in 20 guinea pigs, both sexes, weighing 250-300 g and divided into two groups: I--control (anaesthetized animals without surgery), II--examined (in anaesthetized animals through an incision of the skin and muscles of the neck), the left or right vertebral artery was exposed and a vascular clip was inserted into the foramen of the transverse process of the 2-nd cervical vertebra. 50 days after this procedure, the guinea pigs were again anaesthetized by intraperitoneal injection of 35% solution of chloral hydrate, then vascular and cochlear perfusion with 3.6% solution of glutaraldehyde was performed. Simultaneously, by means of micropreparation, samples of cochlea were made for electron studies by means of electron microscope (Philips EM 300). In qualitative histopathologic examinations in guinea pigs of II group, the ischemia changes of the outer hair cells were greater in the side of irritation of the vertebral artery than at the opposite side. At the receptor side of these cells, under the membrane, there are multilamellar outgrowths in the shape of cisterns, partly expanded. The relative volume of external compartment of mitochondria in control group is as follows respectively: 0.15 +/- 0.0% at the right side and 0.15 +/- 0.08% at the left side, and in II group, respectively: 0.22 +/- 0.06% at the side of irritation and 0.19 +/- 0.07% at the opposite side. The obtained data in electron microscopy, both qualitative and quantitative pointed at ischemia changes of outer hair cells in guinea pigs after prolonged irritation of periarterial plexus of vertebral artery.

Distribution of equivalent doses to skin of the hands of nuclear medicine personnel

During direct contact with radiation sources, for example in nuclear medicine departments, the skin of the hands of workers is the area most exposed to radiation. Measurements with finger dosemeters containing thermoluminescent detectors showed that doses received may reach values as high as 100 mSv y(-1). The specific nature of work performed with isotopes contributes to the considerable differences in the value of an equivalent dose received by the metacarpus, wrist and fingertips. The annual equivalent doses to which fingertips are exposed may exceed the annual dose limit of 500 mSv.

[Therapeutic efficacy assessment of cefuroxime axetil in short 4 day course of empirical antibiotic therapy in patients with bacterial infections of upper respiratory tract and otitis media]

There were examined 261 patients aged 18-62 ambulatory treated and divided into five groups: I--65 patients with acute maxillary sinusitis, II--43 patients with exacerbation of chronic maxillary sinusitis, III--40 patients with angina, IV--61 patients with acute otitis media and V--52 patients with exacerbation of chronic otitis media. Cefuroxime axetil have applied 2 times a day in 500 mg oral dose by 4 days. The therapeutic efficacy of cefuroxime axetil was assessed on the basis: fever chart and self assessment chart of showed symptoms which were assessed from 0 to 4.4 days course antibiotic therapy showed that the total receding of illness symptoms stated in 90.8% patients with acute maxillary sinusitis, in 69.8% patients with exacerbation of chronic maxillary sinusitis, in 62.5% patients with angina, in 91.8% patients with acute otitis media and receding of acute symptoms of exacerbation with chronic otitis media--a ear pain in 88.5% patients and a ear leakage in 44.2% patients. The obtained results stated that the 4 days course of cefuroxime axetil can be sufficient and efficacy in treatment of acute bacterial infections of maxillary sinuses and ear media.