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PubMed1995

Genotoxic effects of two industrial effluents and ethyl methane sulfonate in Clarias lazera.

The genotoxic effects of industrial effluents from a brewery and a textile mill and of ethyl methane sulfonate (EMS) were investigated by the micronucleus test in Clarias lazera, a tropical freshwater fish. Fish obtained from a local market were kept in laboratory aquaria for 3 wk and then exposed to different concentrations (0.5 to 8 mg/litre) of EMS or brewery or textile-mill effluent (10-60%, v/v) for 14 days. The frequency of micronucleated erythrocytes was determined from blood smears and the results were analysed by linear regression and variance analysis. Exposure to EMS or effluent resulted in statistically significant increases in micronucleus frequency and there was a positive dose-response effect over the entire dose range. The textile-mill effluent dose-response curve was significantly higher than that of the brewery effluent. The suitability of the micronucleus test in fish for the screening of aquatic genotoxicants is highlighted and the importance of intensified monitoring of the aquatic environment is emphasized.

Animals↗
PubMed1985

Ultradian and circadian respiratory rhythms in grouped small laboratory vertebrate species as a method to assess the effects of environmental challenges.

The recording over several days of the respiratory gases of groups of different laboratory vertebrates (mice, rats, quails), placed in a chamber with controlled ventilation, and in standardized environmental conditions of temperature, humidity, light, noise and feeding, shows ultradian (tau less than 24 hr) and circadian (tau congruent to 24 hr) rhythms. A simple variance analysis method shows periodic carbon dioxide changes, due to different environmental stimuli. Societal, light, acoustical, carbon monoxide and starvation challenges are given as examples. This technique enables us quickly to collect, on a great number of animals, data which correspond to societal behavior changes peculiar to the considered species.

Acoustic Stimulation↗
PubMed1979

Personality and male-female influences on the EEG alpha rhythm.

The amplitude and frequency of the alpha rhythm was measured in electroencephalic recordings from 45 male and 46 female university students. The mean alpha frequency of the female group was significantly greater than the male group. There was no significant difference in alpha frequency between females in the first half of the menstrual cycle and those in the second half. The relationship between questionnaire measures of psychoticism, extraversion and neuroticism, and the alpha rhythm was investigated using analysis of variance, correlation analysis and factor analysis. Alpha amplitude was significantly greater in extraverted subjects, alpha amplitude and extraversion scores were significantly correlated and both had high loadings on a single factor. No relationship between psychoticism or neuroticism and alpha frequency or amplitude was observed.

Adult↗
PubMed1995

Urinary cGMP levels during pregnancy with and without uterine contractions.

OBJECTIVE: The purpose of this study was to investigate the nitric oxide-cGMP (NO-cGMP) system by urinary cGMP level determinations in pregnant women with and without uterine contractions. DESIGN AND SUBJECTS: cGMP expressed in nmol/mmol of creatinine was performed by radio immuno-assay (Amersham UK) in urine samples obtained from 94 pregnant women with non-complicated pregnancies. Population A without contractions (n = 62) was divided into three groups according to the gestational age (group I, < or = 15 weeks; group II, 16-33 weeks; group III, > 33 weeks). The group III from A population was compared to B population (of the same gestational age) presenting uterine contractions (n = 32). RESULTS: In A population, no significant urinary cGMP level differences were observed whatever the gestational age. Nevertheless, the comparison between patients with or without uterine contractions (A III and B populations) showed a significant difference by a variance analysis (P < 0.05). Lower levels of cGMP were seen when uterine contractions occurred. CONCLUSION: Urinary cGMP levels are significantly decreased in pregnant women with uterine contractions, without any difference from early to late pregnancy. These results, completed by more precise investigations, could suggest that the NO-cGMP system might be implicated in uterine quiescence.

Cyclic GMP↗
PubMed1992

Antitumor activity of thaliblastine (NSC-68075) in experimental ovarian tumor cell lines sensitive and resistant to cisplatin.

Cytotoxicity of thaliblastine (thalicarpine, TBL; NSC-68075) and/or cisplatin (DDP) in DDP-sensitive (O-342) and-resistant (O-342/DDP) rat ovarian tumor cell lines was comparatively determined using the MTT assay. The 50% inhibitory dose (ID50) of DDP was found to be 6.2 microM in O-342 cells and 23.4 microM in O-342/DDP cells, while, vice versa, the ID50 of TBL was 39.3 micrograms/ml in the sensitive line and 27.3 micrograms/ml in the resistant line. Furthermore, simultaneous exposure of cells to DDP and TBL showed a significant superiority over DDP alone in O-342 cells, as evaluated with variance analysis (P less than 0.001). This enhancing effect of TBL on DDP cytotoxicity, however, was not observed in the resistant cells.

Animals↗
PubMed1996

Local hyperthermia of N2/N3 cervical lymph node metastases: correlationof technical/thermal parameters and response.

PURPOSE: Patients with advanced head and neck carcinomas, primarily nonresectable as well as recurrent cases, were treated in multimodality regimens with radiotherapy, chemotherapy, and local hyperthermia. Commercially available microwave and radiowave applicators were used in 50 patients with N2/N3 cervical lymph node metastases during more than 250 heat treatments. To assess technical suitability, the achieved power densities and thermal parameters were tested for correlation with anatomical and geometrical factors. To assess effectiveness, the response was compared with derived parameters of the achieved temperature distributions. METHODS AND MATERIALS: The temperature measurement points (in thermometry catheters) documented by computerized tomography are labeled according to tissue depth, shielding by osseous structures, and location in relation to the external applicators. Relative and absolute specific absorption rates (SAR) and cooling coefficients are extracted from the temperature-time curves. Time-averaged temperature-position curves are evaluated to obtain index temperatures (T90, T50, T20), minimum/maximum tumor temperatures, cumulative minutes T90 > or = 43 degrees C, and 43 degrees C-equivalent min T90. Radiation dose, treatment time, and chemotherapy regiment are also considered. A response parameter is defined using the pre- and posttherapeutic tumor volumes. A multivariate variance analysis is performed for the dependent variables power density, thermal parameters, and response. RESULTS: A significant correlation exists between power density and absorption, presence of a fat layer, and applicator illumination. The maximum depth is 5 cm, where SAR of >= 10 mW/g are registered. Achieved temperatures at individual measurement points are dependent on the SAR, and to a lesser extent, the perfusion-dependent cooling coefficients, but the index temperature T90 is only significantly related to intratumorally achieved SAR. The thermal gradient (T20-T50) and temperature peak (T20) are significantly influenced by the tumor volume. The response is directly related to the index temperature T90, equivalent minute T90 43 degrees C, and cumulative minutes T90 > or = 40.5 degrees C, and inversely related to the tumor volume. CONCLUSIONS: Local hyperthermia using microwave and radiowave applicators in the head and neck region is a tolerable and clinically practical supplementary therapy used as part of multimodal regimens, and has already been proven to be effective. However, the analyses also demonstrated the limits of currently available technology, and confirm the need for continued methodical research.

Adult↗
PubMed1993

Influence of spontaneous and surgical menopause on atherogenic metabolic risk.

We evaluated serum total-, LDL-, HDL-, cholesterol and triglycerides in 858 women. Sixty-seven were in premenopause, 307 in perimenopause, 326 in spontaneous menopause, and 158 women underwent hysterectomy. Of these, 101 had bilateral ovariectomy, 24 with unilateral ovariectomy and 33 with retention of both ovaries. After correcting for chronological age and body mass index by variance analysis, it was found that total-, LDL- and HDL-cholesterol significantly increased during menopause without changes in the total cholesterol/HDL-cholesterol, LDL-cholesterol/HDL-cholesterol and triglycerides/HDL-cholesterol ratio. The changes gradually occurred during the months preceding spontaneous cessation of menses. Atherogenic metabolic risk (as relative risk of high total and LDL-cholesterol, estimated by logistic regression analysis) significantly increased in all groups of women in reference to premenopause. The risk observed in surgical menopause with bilateral ovariectomy was higher than in spontaneous menopause, and conservation of ovaries in hysterectomized women seems to protect only partially against such an increase.

Adult↗
PubMed1989

Variability of indexes for myocardial ischemia: a comparison of exercise treadmill test, ambulatory electrocardiographic monitoring and symptoms of myocardial ischemia.

Fifty-four patients with chronic stable angina were studied to determine and compare weekly variability of indexes for the detection of myocardial ischemia. All patients underwent three single-blind placebo periods, each lasting 1 week. An exercise treadmill test, 24 h ambulatory electrocardiographic (Holter) monitoring (analyzed blindly) and an accurate diary of anginal attacks and nitroglycerin use were obtained at the end of each placebo period. An unbalanced, completely random component of variance analysis was used to calculate a component for within subject variability and a component for among subject variability. The coefficient of variation and percent variation (within subjects) of onset of chest pain during exercise were 19% and 30%, respectively; the corresponding values were 28% and 33% for onset of 1 mm ST depression, 15% and 15% for exercise duration, 44% and 27% for number of ischemic episodes/24 h, 56% and 43% for anginal frequency and 55% and 27% for nitroglycerin consumption, respectively. With use of this statistical method and variation within subjects, the change in the value of each variable necessary to exceed those attributable to spontaneous variation was determined. The trade-off between repeated measurements and number of subjects, the sample size estimated for planning studies and the minimal sample size for using various designs were also determined. Although the data indicate that all indexes for myocardial ischemia, both during exercise and during daily activity, vary considerably, but the exercise variables have less variability and are more reproducible.(ABSTRACT TRUNCATED AT 250 WORDS)

Ambulatory Care↗
PubMed1991

Modulation of excitatory synaptic transmission by drugs that reduce desensitization at AMPA/kainate receptors.

Desensitization at AMPA/kainate receptors has been proposed to contribute to the decay of excitatory synaptic currents. We examined the action of aniracetam, wheat germ agglutinin (WGA), and concanavalin A (Con A), drugs that act via separate mechanisms to reduce desensitization evoked by L-glutamate in rat hippocampal neurons. The decay of excitatory synaptic currents, and sucrose-evoked miniature excitatory postsynaptic currents (EPSCs) was slowed 2- to 3-fold by aniracetam. In contrast, WGA increased the EPSC decay time constant only 1.3-fold and Con A had no effect. Aniracetam increased the magnitude of stimulus-evoked EPSCs 1.9-fold; variance analysis suggests a postsynaptic mechanism of action. WGA and Con A reduced EPSC amplitude via a presynaptic mechanism. Aniracetam increased the burst length of L-glutamate-activated single-channel responses. Simulations suggest that aniracetam either slows entry into a desensitized state or decreases the closing rate constant for ion channel gating.

Animals↗
PubMed1992

Activation and desensitization of glutamate-activated channels mediating fast excitatory synaptic currents in the visual cortex.

Brief glutamate applications to membrane patches, excised from neurons in the rat visual cortex, were used to assess the role of desensitization in determining the AMPA/kainate receptor-mediated excitatory postsynaptic current (EPSC) time course. A brief (1 ms) application of glutamate (1-10 mM) produced a response that mimicked the time course of miniature EPSCs (mEPSCs). Direct evidence is presented that the rate of onset of desensitization is much slower than the decay rate of the response to a brief application of glutamate, implying that the decay of mEPSCs reflects channel closure into a state readily available for reactivation. Rapid application of glutamate combined with nonstationary variance analysis provided an estimate of the single-channel conductance and open probability, allowing an approximation of the number of available channels at a single synaptic site.

Animals↗
PubMed2005

Comparison of amniotic and intramembranous unidirectional permeabilities in late-gestation sheep.

OBJECTIVE: Amniotic fluid volume is regulated by the intrinsic modulation of intramembranous absorption. However, neither the mechanisms nor the rate-limiting barriers of this transport are known. We tested the hypothesis that the amnion is the rate-limiting barrier of intramembranous absorption by comparing unidirectional permeabilities of the amnion in vitro and the intramembranous pathway in vivo. STUDY DESIGN: Unidirectional permeabilities to 99m technetium pertechnate or [14 C]inulin of fresh ovine amnion were measured in vitro in a Ussing chamber; the permeability-surface area products were calculated by the multiplication of the permeabilities by gestational age-specific amniotic surface areas. Unidirectional permeabilities of the intramembranous pathway of the 2 tracers were calculated from solute fluxes between amniotic fluid and fetal blood in chronically catheterized late-gestation fetal sheep. Statistical comparisons included t -tests, least squares regression, analysis of variance, and analysis of covariance. RESULTS: In the isolated amnion in vitro, the ratio of permeabilities in the amniotic fluid to chorionic direction and the reverse direction was not significantly different from unity for 99m technetium pertechnate (1.03+/-0.10 [SE]; n=7) or [14 C]inulin (1.10+/-0.17; n=7). In contrast, in the in vivo preparation, the ratio of intramembranous permeabilities outward from the amniotic fluid and the reverse direction was greater than unity for 99m technetium pertechnate (2.10+/-0.34; n=8; P=.014) and [14 C]inulin (4.68+/-1.24; n=7; P=.025). The permeability-surface area product of 99m technetium pertechnate (2.18+/-0.79 mL/min) of the isolated amnion was similar to the in vivo intramembranous permeability (n=8) in the amniotic fluid to fetal blood direction (1.42+/-0.34 mL/min) and greater than that in the reverse direction (0.84+/-0.25 mL/min; P=.046). The permeability-surface area product of [14 C]inulin of the amnion (0.53+/-0.20 mL/min) was similar to intramembranous permeability (n=7) in the amniotic fluid to fetal blood (0.68+/-0.15 mL/min) direction and greater than that in the reverse direction (0.22+/-0.06 mL/min; P=.0097). CONCLUSION: Solute transport across the ovine amnion depends on solute size and appears to be limited only by the amnion's passive diffusional properties. In vivo intramembranous transport similarly depends on solute size but is not exclusively a passive diffusional process because it is primarily unidirectional outward from the amniotic fluid. Although it is a major barrier, the amnion is not the only barrier and does not appear to be responsible for the unidirectional nature of intramembranous absorption. Thus, unidirectionality appears to be imparted by nonpassive mechanisms in non-amnion tissues, which most likely includes vesicular transport within the endothelial cells of the intramembranous microvessels.

Absorption↗
PubMed2006

[Is entropy a monitor for the guidance of intraoperative analgesia?].

OBJECTIVE: Comparison between BIS (Bispectral Index) and state (SE) and response (RE) entropy during laparotomy for inflammatory bowel disease patients (IBD) and evaluation of the variations of RE and SE during nociceptive stimulation. STUDY DESIGN: Prospective, observational study. PATIENTS AND METHODS: Fourteen IBD's patients undergoing laparotomy were included. Anaesthesia aimed to maintain BIS between 40 and 60 by isoflurane and nitrous oxide. Analgesia was performed by sufentanil bolus administrated according to an increase of 20% of systolic blood pressure (SBP) and heart rate compared with the baseline values. BIS, RE and SE were measured at each nociceptive stimulation. A variance analysis (Anova) was used to assess BIS, RE and SE variations throughout surgery (p<0.05 as significant). Relationship between BIS, RE and SE was assessed by Pearson correlation (p<0.01 as significant). The ability for SE and RE to predict depth of anaesthesia and intraoperative analgesia was performed by calculating area under the receiver operated curves (AUC). RESULTS: BIS and entropy parameters had strictly the same evolution during anaesthesia. SBP increased significantly during nociceptive stimulation while no variation of RE was observed. A significant correlation was shown between BIS, RE and SE. The evaluation of anaesthesia depth was good for RE (AUC: 0.932+/-0.26) and SE (AUC: 0.926+/-0.27). There was however no difference between RE and SE to predict analgesic requirement. CONCLUSION: Because RE includes muscular frequency analysis, it does not allow analgesic requirement evaluation in paralyzed patients.

Adult↗
PubMed2005

Optimization of a model of red blood cells for the study of anti-oxidant drugs, in terms of concentration of oxidant and phosphate buffer.

The aggression of erythrocytes by an oxidative stress induces hemolysis. This paper aims to valid a model of erythrocytes in terms of composition of the phosphate buffer solution and of concentration of a well-known oxidant, AAPH. Three compositions of phosphate buffer solution are mixed with three concentrations of oxidant. The influence of these two parameters on hemolysis is independently studied by a variance analysis and a Kruskal-Wallis test when ANOVA is not available. The hemolysis rate increases with time at fixed oxidant concentration, but is not influenced by the composition of the buffer solution. The highest hemolysis rate, 90%, was only measured within 2 h with the highest oxidant concentration. If we retain this concentration of oxidant, the lower concentration of the buffer can by eliminated by a significant less hemolysis and the highest concentration of the buffer can by chosen in regard of the better precision for a similar hemolysis compared to the mean buffer. We hope to study the effect of anti-oxidant agent with such a model of erythrocytes.

Antioxidants↗
PubMed2005

Can follow-up radiography for acute scaphoid fracture still be considered a valid investigation?

AIM: To determine whether follow-up radiography is a valid diagnostic investigation in patients with suspected acute scaphoid fractures and normal initial radiographs. MATERIALS AND METHODS: Fifty sets of radiographs (initial and follow-up) were independently assessed by four expert observers for the presence or absence of a scaphoid fracture. Magnetic resonance imaging (MRI), performed in all cases, was used as the gold standard to determine the sensitivity, specificity, positive and negative predictive values of the observers' assessment of the follow-up radiograph. In addition, the reliability among observers of the follow-up radiograph was determined by reliability variance analysis. RESULTS: Of the 50 sets of radiographs, 35 patients had a scaphoid fracture and 15 were normal, as established from MRI report. For individual observer's assessment of the follow-up radiograph, sensitivities of 11, 9, 43 and 49%; specificities of 93, 93, 87 and 80%; positive predictive values of 80, 75, 88 and 85%; and negative predictive values of 31, 30, 39 and 40%. A reliability coefficient of more than 60% is needed for a diagnostic test to be considered reliable. Overall, the inter-observer reliability coefficient was 33%, with pair-wise inter-observer coefficients ranging from 18-53%. CONCLUSION: With poor sensitivity, poor negative predictive value and poor reliability, follow-up radiography cannot be considered a valid diagnostic examination for the detection of scaphoid fracture in patients with normal initial radiographs.

Adolescent↗
PubMed2004

Influence of mechanical and chemical polishing in the solubility of acrylic resins polymerized by microwave irradiation and conventional water bath.

OBJECTIVES: The aim of this work was to evaluate the solubility of acrylic resin activated by microwave irradiation (MI) or water bath (WB), when submitted to chemical (CP) or mechanical (MP) polishing. METHODS: Forty acrylic resin samples were made and processed either by water bath (74 +/- 1 degrees C, 9 h) or microwave irradiation (500 W, 3 min). After deflasking, the samples were finished with aluminum oxide sandpapers in decreasing granulations till reaching similar dimensions. The samples were divided into four groups according to the association between kind of polymerization and polishing: A (WB + CP), B (WB + MP), C (MI + CP) and D (MI + MP). Solubility test was performed for each group and percentile solubility was calculated. Data were statistically analyzed using variance analysis and Kruskal-Wallis. RESULTS: The average of percentile solubility (%) was obtained: A = 0.07, B = 0.02, C = 0.04, D = -0.14, however, no significant difference was found between types of polishing in the samples polymerized by water bath (A and B). When processed by microwave irradiation (C and D), there was significant difference between the applied methods of polishing, so that mechanical polishing lead to a lower solubility. SIGNIFICANCE: Solubility is a property of acrylic resins, representing not reacted substances releasing that could promote tissular reactions in prosthesis users. The association between polymerization by microwave irradiation and mechanical polishing showed less residual substances releasing for heat-cured acrylic resins, reducing the probability of developing tissular reactions.

Acrylic Resins↗
PubMed2005

Hand grip strength in patients with type 2 diabetes mellitus.

AIM: The aim of the present study was to compare hand grip strength and pinch power, which are important parameters of hand function, in 76 patients with type 2 diabetes mellitus (T2DM) (mean age: 50.11+/-7.6) with 47 non-diabetic control subjects (mean age: 46.93+/-10.2). METHODS: Grip strength was assessed with a Jamar dynamometer and pinch power was measured with a pinch gauge. Body composition was measured using a Tanita body composition analyzer. Mann-Whitney test, chi-square test, Fisher's exact test, T-test, Kruskal-Wallis variance analysis, Wilcoxon's signed rank test and Pearson's correlation coefficients were used to determine the differences and relations between groups. A p-value <0.05 was taken as statistically significant. RESULTS: Hand grip strength test values were significantly lower in the diabetic group compared with the control group. Key pinch power value for the right hand was significantly lower in the diabetic group than in the control group whereas the left hand value was similar. CONCLUSION: Hand grip strength and key pinch power values were found to be lower in patients with T2DM than in age-matched control subjects. Hands, as well as feet, are also affected by diabetes and physicians should be aware of this.

Adult↗
PubMed2006

Relative contribution of food and water to 27 metals and metalloids accumulated by caged Hyalella azteca in two rivers affected by metal mining.

Hyalella were caged at three sites in each of the two rivers for 17 days. Food added to the cages consisted of plant and detrital material collected from the same, or other, sites. Concentrations of some metals in Hyalella (e.g., Cd and Cu), but not others (e.g., Se), appeared to reach steady-state within 5 days in one of the rivers. Metal accumulation was minimal by day 5 in the other river, possibly due to the very low temperatures in this river for the first part of the exposure period. Both analysis of variance and analysis of covariance, using site as a categorical variable and metal in food as either a categorical or continuous variable, indicated that Cd, Cu and Se were the only metals for which concentration in food had a significant effect on concentration in Hyalella. Nevertheless, water was still a major source for these metals as well. Other metals which varied by over fivefold in food but for which concentration in food had no effect on concentration in Hyalella included Ag, As, Bi, Sb, U and Zn. Concentrations of the remaining metals varied less than fourfold in food, making it difficult to determine if these were accumulated from food.

Amphipoda↗
PubMed2006

Expression profiling of Botrytis cinerea genes identifies three patterns of up-regulation in planta and an FKBP12 protein affecting pathogenicity.

The ascomycete Botrytis cinerea is a broad-spectrum plant pathogen. Here, we describe the first macroarray transcriptomic study of the fungus in real-time infection conditions. Infection of Arabidopsis thaliana leaves by B.cinerea was monitored using macroarrays, containing 3032 genes. Variance analysis revealed that 7% of B.cinerea genes are differentially expressed during infection and allowed us to identify 27 genes significantly up-regulated in planta. Among them, two genes have already been associated with fungal pathogenicity, while eight genes have unidentified functions. The 27 genes were separated into three groups according to their expression profile. The first group showed maximal expression at the early stage following fungal penetration, the second one showed maximal expression at the outset of the colonization of plant leaves and the third group showed maximal expression when the colonization of plant leaves was completed. A gene of the last group (BcPIC5), which is homologous to FKBP12 proteins, was disrupted in order to determine its role in pathogenicity. At seven days post-inoculation, the lesions caused by the DeltaBcPIC5 mutant on bean leaves were reduced by 69% and did not further expand compared to the wild-type. These results confirm that transcriptomic analysis under infection conditions can be very valuable for the identification of fungal genes related to pathogenicity.

Arabidopsis↗