999 resultados para Half-normal plot
Resumo:
In many tumors, the amount of chondroitin sulfate in the extracellular matrix has been shown to be elevated when compared to the corresponding normal tissue. Nevertheless, the degree of chondroitin sulfate increase varies widely. In order to investigate a possible correlation between the amount of chondroitin sulfate and tumor size, several individual specimens of human leiomyoma, a benign uterine tumor, were analyzed. The glycosaminoglycans from eight tumors were extracted and compared with those from the respective adjacent normal myometrium. The main glycosaminoglycan found in normal myometrium was dermatan sulfate, with small amounts of chondroitin sulfate and heparan sulfate. In leiomyoma, both dermatan sulfate and chondroitin sulfate were detected and the total amounts of the two galactosaminoglycans was increased in all tumors when compared to normal tissue. In contrast, the heparan sulfate concentration decreased in the tumor. To assess the disaccharide composition of galactosaminoglycans, these compounds were incubated with bacterial chondroitinases AC and ABC. The amounts of L-iduronic acid-containing disaccharides remained constant, whereas the concentration of D-glucuronic acid-containing disaccharides increased from 2 to 10 times in the tumor, indicating that D-glucuronic acid-containing disaccharides are responsible for the elevation in galactosaminoglycan concentration. This increase is positively correlated with tumor size.
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Ketamine is believed to reduce airway and pulmonary tissue resistance. The aim of the present study was to determine the effects of ketamine on the resistive, elastic and viscoelastic/inhomogeneous mechanical properties of the respiratory system, lungs and chest wall, and to relate the mechanical data to findings from histological lung analysis in normal animals. Fifteen adult male Wistar rats were assigned randomly to two groups: control (N = 7) and ketamine (N = 8). All animals were sedated (diazepam, 5 mg, ip) and anesthetized with pentobarbital sodium (20 mg/kg, ip) or ketamine (30 mg/kg, ip). The rats were paralyzed and ventilated mechanically. Ketamine increased lung viscoelastic/inhomogeneous pressure (26%) compared to the control group. Dynamic and static elastances were similar in both groups, but the difference was greater in the ketamine than in the control group. Lung morphometry demonstrated dilation of alveolar ducts and increased areas of alveolar collapse in the ketamine group. In conclusion, ketamine did not act at the airway level but acted at the lung periphery increasing mechanical inhomogeneities possibly resulting from dilation of distal airways and alveolar collapse.
The effect of porphyrins on normal and transformed mouse cell lines in the presence of visible light
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Photodynamic therapy consists of the uptake of a photosensitizing dye, often a porphyrin, by tumor tissue and subsequent irradiation of the tumor with visible light of an appropriate wavelength matched to the absorption spectrum of the photosensitizing dye. This class of molecules produces reactive oxygen species when activated by light, resulting in a direct or indirect cytotoxic effect on the target cells. Photodynamic therapy has been used in the treatment of cancer but the technology has a potential for the treatment of several disease conditions mainly because of its selectivity. However, it is not clear why the porphyrins are retained preferentially by abnormal tissue. This paper describes a study of the effect of the association of porphyrin and visible light on two mouse fibroblast cell lines: A31, normal cells and B61, an EJ-ras transformed variant of A31. Two water-soluble porphyrins were used, a positively charged one, tetra(N-methyl-4-pyridyl)porphyrin chloride, and a negatively charged one, tetra(4-sulfonatophenyl)porphyrin-Na salt (TPPS4) in order to assess the effect on cell survival. The results suggest that the B61 cell line is more sensitive to incubation with the anionic porphyrin (TPPS4) followed by light irradiation and that the anionic porphyrin is more efficient in killing the cells than the cationic porphyrin.
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In order to identify latent bioelectrical oscillators, 15 normal subjects (aged 9-17 years, 8 males, 7 females) were subjected to intermittent photic stimulation. The EEG amplitude spectra corresponding to the 11 fixed frequencies of stimulation presented (3-24 Hz) were combined to form "profiles" of the driving reaction in the right occipital area. The driving response varied with frequency, and was demonstrable in 70-100% of cases (using as criterion peak amplitudes 20% larger than those of the neighbors). The strongest responses were observed at the frequency closest to the alpha peak of the resting EEG. A secondary profile maximum was in the theta band. In 10 subjects, this maximum exceeded half the alpha peak (with an average of 72.4% of the alpha peak), while in the resting spectra, theta amplitudes were much lower than the alpha maxima. This responsiveness in theta activity seems to be characteristic of prepubertal and pubertal subjects. The profiles and resting EEG spectra showed a highly significant Pearson's correlation, with the peak in the theta band of the profiles being the main difference observed between them. The correlation coefficient was significantly correlated with the ratio of the maxima in the theta and alpha bands (R = -0.77, P<0.001). The correlation coefficient between profile and resting spectrum may be a useful indicator in screening methods used to reveal latent cerebral oscillators. Profiles for the second and third harmonics were correlated with those of the first harmonic (fundamental frequency), when considering the corresponding EEG frequencies. Peak frequencies in all three profiles were close to those of the individual's background alpha rhythm, and peak amplitudes in higher harmonics were not much lower than those of the fundamental frequency (mean values of 84 and 63%, for second and third harmonics, respectively).
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Undernutrition of dams and pups disrupts the retrieval efficiency of mothers. However, if the mothers are assessed in their home cages, they spend more time with their litters. In the present study the effect of test conditions on pup retrieval behavior of mothers receiving a 25% (well-nourished group) and 8% casein diet (undernourished group) was examined. In agreement with previous studies, undernourished mothers spent more time with their litters than well-nourished dams as lactation proceeded. Pup retrieval behavior varied with test conditions. In the first experiment, the maternal behavior of dams was assessed by the standard procedure (pups were separated from their mother and scattered over the floor of the home cage). The mother was then returned and the number of retrieved pups was recorded. From day 3 to 8, the retrieval efficiency of undernourished dams decreased, while the retrieval efficiency of well-nourished mothers did not vary. In the second experiment, mothers were subjected to a single retrieval test (on day 9 of lactation) using the procedure described for experiment 1. No difference between well-nourished and undernourished mothers was observed. In the third experiment, seven-day-old pups were separated from the mothers and returned individually to a clean home cage. Dietary treatment did not affect the retrieval efficiency. However, undernourished dams reconstructed the nest more slowly than did well-nourished dams. Taken together, these results suggest that pup retrieval behavior of the undernourished mother is not impaired by dietary restriction when the maternal environment is disturbed minimally.
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The early demonstration of lung involvement in systemic lupus erythematosus (SLE) patients is a difficult but important task. In the present study we attempted to identify abnormalities in pulmonary clearance of 99mTc-DTPA in SLE, correlating their clearance data with clinical findings and disease activity. Forty-six consecutive SLE patients with and without active disease (LACC score) and 30 normal volunteers were studied. All subjects were submitted to pulmonary scintigraphy with 99mTc-DTPA to evaluate the pulmonary clearance, and to a chest X-ray, and SLE patients were submitted to tests of disease activity, spirometry, arterial blood gases and tests to assess acute-phase proteins. Pulmonary clearance was faster in SLE patients with active disease when compared to normal controls [half-life of 67.04 min (51.52-82.55 min) in active SLE versus 85.87 min (78.85-92.87 min) in controls, P<0.05] and there was a higher frequency of abnormal clearance rates in patients with active disease (11 of 26 patients, 42.3%) when compared with SLE patients without disease activity (2 of 20 patients, 10%) (P = 0.04). A significant correlation was observed between the clearance rates and cough (P<0.05), but not between the clearance rates and dyspnea symptoms or radiological findings, duration of SLE disease, antinuclear antibody titers and patterns, C-reactive protein or anti-double stranded DNA antibodies. We conclude that the pulmonary clearance of 99mTc-DTPA is increased in SLE patients with active disease.
Resumo:
This thesis presents point-contact measurements between superconductors (Nb, Ta, Sn,Al, Zn) and ferromagnets (Co, Fe, Ni) as well as non-magnetic metals (Ag, Au, Cu, Pt).The point contacts were fabricated using the shear method. The differential resistanceof the contacts was measured either in liquid He at 4.2 K or in vacuum in a dilutionrefrigerator at varying temperature down to 0.1 K. The contact properties were investigatedas function of size and temperature. The measured Andreev-reflection spectrawere analysed in the framework of the BTK model – a three parameter model that describescurrent transport across a superconductor - normal conductor interface. Theoriginal BTK model was modified to include the effects of spin polarization or finitelifetime of the Cooper pairs. Our polarization values for the ferromagnets at 4.2 K agree with the literature data, but the analysis was ambiguous because the experimental spectra both with ferromagnets and non-magnets could be described equally well either with spin polarization or finite lifetime effects in the BTK model. With the polarization model the Z parametervaries from almost 0 to 0.8 while the lifetime model produces Z values close to 0.5. Measurements at lower temperatures partly lift this ambiguity because the magnitude of thermal broadening is small enough to separate lifetime broadening from the polarization. The reduced magnitude of the superconducting anomalies for Zn-Fe contacts required an additional modification of the BTK model which was implemented as a scaling factor. Adding this parameter led to reduced polarization values. However, reliable data is difficult to obtain because different parameter sets produce almost identical spectra.
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Two radioaerosol preparations, TechneScan®-DTPA (99mTc-DTPA, 40 mCi/3 ml; IPEN-CNEN, São Paulo, SP, Brazil) and TechneScan®-DTPA/AEROSOL (99mTc-DTPA/A, 15 mCi/1.5 ml with 0.5 ml ethanol; Mallinckrodt Medical, St. Louis, MO, USA), were compared in pulmonary ventilation studies in terms of total radiocounts and clearance after inhalation. An aerosol with ethanol is supposed to better distribute the radioparticles in the lungs. Twenty normal nonsmoking volunteers (10 men and 10 women), mean age of 23.2 years (range: 20 to 35 years), were studied. Images were obtained immediately and 30, 60 and 90 min after inhalation. Total and regional counts were obtained and the clearance half-lives of both lungs were determined. There was no difference in total counts between the two types of radioaerosol at any time (mean of ~188,000 cpm for male and female subjects at time zero in both aerosols). The highest count was obtained in the middle region of both lungs (P<0.001) with both preparations. The clearance half-life did not differ between aerosols (mean of ~80-88 min for male and female subjects for both aerosols). Small nonsignificant regional differences were observed. No differences between genders or between right and left lung were observed. 99mTc-DTPA/A generated the highest output of radioaerosol. 99mTc-DTPA with alcohol costs approximately five times more than the aerosol without alcohol. The present results show that either kind of aerosol may be adopted routinely for use in pulmonary examinations without affecting diagnosis. We suggest that the amount of 740 mBq (20 mCi) of 99mTc-DTPA in 1.5 ml saline can be used for routine examinations resulting in reduction of costs in pulmonary ventilation studies without diagnostic impairment.
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The aim of the present study was to determine the expression of the genes for type 1 (SDR5A1) and type 2 (SDR5A2) 5alpha-reductase isoenzymes in scalp hairs plucked from 33 hirsute patients (20 with polycystic ovary syndrome and 13 with idiopathic hirsutism) and compare it with that of 10 men and 15 normal women. SDR5A1 and SDR5A2 expression was estimated by RT-PCR using the gene of the ubiquitously expressed protein ß2-microglobulin as an internal control. The results are expressed as arbitrary units in relation to ß2-microglobulin absorbance (mean ± SEM). SDR5A2 expression was not detected in any hair samples analyzed in this study. No differences were found in SDR5A1 mRNA levels between men and normal women (0.78 ± 0.05 vs 0.74 ± 0.06, respectively). SDR5A1 gene expression in the cells of hair plucked from the scalp of normal women (0.85 ± 0.04) and of women with polycystic ovary syndrome (0.78 ± 0.05) and idiopathic hirsutism (0.80 ± 0.06) was also similar. These results indicate that SDR5A1 gene expression in the follicular keratinocytes from the vertex area of the scalp seems not to be related to the differences in hair growth observed between normal men and women and hirsute patients. Further studies are needed to investigate the expression of the 5alpha-reductase genes in other scalp follicular compartments such as dermal papillae, and also in hair follicles from other body sites, in order to elucidate the mechanism of androgen action on the hair growth process and related diseases.
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The multidrug resistance P-glycoprotein is a transmembrane efflux pump expressed by lymphocytes and is involved in their cytolytic activity. In the present study, we investigated the age-related changes of P-glycoprotein function in normal peripheral blood lymphocytes. Blood samples from 90 normal volunteers (age range, 0 to 86 years) were analyzed. P-glycoprotein function was assessed by the flow cytometric rhodamine 123 assay. P-glycoprotein function was highest in cord blood and progressively declined with age in peripheral blood T CD4+ and CD8+ cells. In contrast, P-glycoprotein function did not vary with age in CD19+ B or CD16+CD56+ natural killer cells. These data suggest that the decline in P-glycoprotein function in T CD4+ and CD8+ lymphocytes as a function of age may contribute to the decrease in T cell cytolytic activity with aging.
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The objective of the present study was to determine the effects of retinoic acid on the growth of the mouse mammary cells HC11 and HC11ras, which are a model for in vitro breast cancer progression. The expression of the two classes (RARs and RXRs) of retinoic acid receptor mRNAs was determined by Northern blot analysis. Receptor functional integrity was determined by testing whether RAR ß mRNA could be induced by retinoic acid. The effects of a 72-h exposure to 50 µM 13-cis retinoic acid on HC11 and HC11ras cell proliferation and HC11 cell differentiation were investigated by flow cytometric cell cycle analysis, and by determination of ß-casein mRNA expression, respectively. The possibility that retinoic acid would induce the expression of the vitamin D receptor and synergize with vitamin D, a known inhibitor of HC11 cell growth, was also investigated. HC11 cells expressed higher mRNA levels of both RAR a and RAR g when compared to HC11ras cells. In contrast, RAR ß, as well as RXR a, ß and g expression was low in both HC11 and HC11ras cells. In addition, RAR ß mRNA was induced by retinoic acid treatment in both cells. In spite of these observations, no effects were seen on cell proliferation or differentiation upon exposure to retinoic acid. Neither vitamin D receptor induction nor synergy with vitamin D on growth inhibition was observed. We conclude that the RAR expression profile could be related to the transformed state in HC11ras cells and that the retinoic acid resistance observed merits further investigation.
Resumo:
Estrogen (ER) and progesterone (PR) receptors in the normal uterine cervix, cervical intraepithelial neoplasia and invasive carcinoma were studied in consecutive samples from Hospital do Câncer, São Paulo, between 1996 and 1997. Tissue was collected by removing a fragment of the tumoral area using a 5-mm diameter biopsy punch, followed by removal of a macroscopically normal area as close as possible from the tumor. Histopathological confirmation was obtained for all specimens analyzed. A total of 24 normal tissues, 17 cases of cervical intraepithelial neoplasia and 7 of invasive carcinomas were studied. The ER/PR ratio was determined by immunohistochemistry using monoclonal antibodies specific for each receptor. Adjacent tissue slides were submitted to generic PCR for human papillomavirus (HPV) DNA detection followed by typing by dot blot hybridization. About half (45.8%) of the tumors were HPV DNA positive while 29.1% of the patients were also HPV positive in their respective normal tissue. ER was negative in the tumoral epithelium of 11 HPV-positive patients (P = 0.04). There was a trend in the ER distribution in normal tissue that was opposite to that from lesions, but it was not statistically significant (P = 0.069). No difference in ER distribution in stromal tissues was observed between HPV-positive and HPV-negative tissues. PR staining was negative in the epithelium of all cases studied. The results obtained from this small number of cases cannot be considered to be conclusive but do suggest that factors related to viral infection affect the expression of these ER/PR cervix receptors.
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The actin cytoskeleton is a dynamic structure that determines cell shape. Actin turnover is mandatory for migration in normal and malignant cells. In epithelial cancers invasion is frequently accompanied by epithelial to mesenchymal transition (EMT). In EMT, cancer cells acquire a migratory phenotype through transcriptional reprogramming. EMT requires substantial re-organization of actin. During the past decade, new actin regulating proteins have been discovered. Among these are members of the formin family. To study formin expression in tissues and cells, antibodies for detection of formin proteins FMNL1 (Formin-like protein 1), FMNL2 (Formin-like protein 2) and FHOD1 (Formin homology 2 domain containing protein 1) were used. The expression of formins was characterized in normal tissues and selected cancers using immunohistochemistry. The functional roles of formins were studied in cancer cell lines. We found that FMNL2 is widely expressed. It is a filopodial component in cultured melanoma cells. In clinical melanoma, FMNL2 expression has prognostic significance. FHOD1 is a formin expressed in mesenchymal cell types. FHOD1 expression is increased in oral squamous cell carcinoma (SCC) EMT. Importantly, FHOD1 participates in invasion of cultured oral SCC cells. FMNL1 expression is low in normal epithelia, but high in leukocytes and smooth muscle cells. Expression of FMNL1 can be found in carcinoma; we detected FMNL1 expressing cells in basal type of breast cancer. Our results indicate that formins are differentially expressed in normal tissues and that their expression may shift in cancer. Functionally FMNL2 and FHOD1 participate in processes related to cancer progression. Studying formins is increasingly important since they are potential drug targets.
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The use of bovine pericardium as a urethral patch to substitute a ventral segment of canine urethras was studied. Healing, epithelial growth, urethral permeability, fistulas, and calcification were analyzed. Thirty male mongrel dogs of medium and large size underwent resection of a ventral segment of the medial urethra measuring 2.0 x 0.5 cm, which was replaced with a bovine pericardium graft, treated with buffered glutaraldehyde and preserved in formaldehyde. Two running sutures of polygalactin 5-0 were applied, one on each side of the patch. The corpus spongiosum was closed with uninterrupted suture and the skin with interrupted suture of polygalactin 5-0. Six months later, the animals were examined and sacrificed under anesthesia. Retrograde urethrograms showed that the urethral healing was complete in six of the 30 animals, without stenosis, fistulas or dilations. Microscopic examination showed complete epithelization of these six urethras. The remaining 24 animals presented urethrocutaneous fistulas without stenosis, demonstrated by urethral catheterism using a 10-Fr plastic catheter. These data show that a successful urethral reconstruction of the penile urethra was possible in only 20% of the operated animals. Infection and leakage may be the cause of the urethrocutaneous fistulas present in 80% of cases. Further studies are necessary to determine whether such fistulas are avoidable. If they are, the bovine pericardium may well be an option in the treatment of urethral lesions in dogs.
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Panic disorder is thought to involve dysfunction in the septohippocampal system, and the presence of a cavum septum pellucidum might indicate the aberrant development of this system. We compared the prevalence and size of cavum septum pellucidum in 21 patients with panic disorder and in 21 healthy controls by magnetic resonance imaging. The length of the cavum septum pellucidum was measured by counting the number of consecutive 1-mm coronal slices in which it appeared. A cavum septum pellucidum of >6 mm in length was rated as large. There was no significant difference in the proportion of patients (16 of 21 or 76.2%) and controls (18 of 21 or 85.7%) with a cavum septum pellucidum (P = 0.35, Fisher's exact test, one-tailed), and no members of either group had a large cavum septum pellucidum. The mean cavum septum pellucidum rating in the patient and control groups was 1.81 (SD = 1.50) and 2.09 (SD = 1.51), respectively. There were also no significant differences between groups when we analyzed cavum septum pellucidum ratings as a continuous variable (U = 196.5; P = 0.54). Across all subjects there was a trend towards a higher prevalence of cavum septum pellucidum in males (100%, 10 of 10) than females (75%, 24 of 32; P = 0.09, Fisher's exact test, one-tailed). Thus, we conclude that, while panic disorder may involve septo-hippocampal dysfunction, it is not associated with an increased prevalence or size of the cavum septum pellucidum.