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Highly Significant Increase (highly + significant_increase)
Selected AbstractsAge-dependent differential expression of genes involved in steroid signalling pathway in the brain of protandrous black porgy, Acanthopagrus schlegeliDEVELOPMENTAL NEUROBIOLOGY, Issue 5 2009Sherly Tomy Abstract The mechanisms underlying brain sex differentiation in animals are poorly understood. In the present study, using black porgy, Acanthopagrus schlegeli, as primary experimental model, we investigated the temporal expression patterns of receptors for androgen (ar) and estrogen (esr1 and esr2a) in the brain during posthatching ages and analyzed them against the timing of gonadal germ cell development. We hypothesized that endogenous estrogens naturally masculinize the brain of black porgy. The expression of sex steroid receptors was studied in relation to a wider suite of other related genes (nr5a2, nr0b1, star, and cyp19a1b) to provide some insight into the monomale sex differentiation pattern observed in this species. Our results revealed a highly significant increase in esr1 together with the increase in esr2a at 120 dph (days posthatching), suggesting a significant role for esr in sex differentiation in this species. Temporal expression patterns of nr5a2, nr0b1, star, sex steroid receptors, and cyp19a1b in the brain provided evidence for their physiological roles in the monomale sex differentiation in this species. The expression of nr5a2, star, ar, esr1, esr2a, and cyp19a1b increased at 120 dph, a period when brain sex differentiation probably occurs in this species. The study also suggests that neurosteroidogenesis in black porgy may be regulated by both nr5a2 -dependent and nr5a2 -independent mechanisms. The results demonstrated striking differences in the abundance of the gene transcripts in discrete brain region throughout ontogeny. In addition, the sex steroid hormone levels and aromatase activity in brain at different developmental states and the changes in the gene expression patterns in response to aromatase inhibitor treatment are also discussed. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2009 [source] Age-related changes in transient and oscillatory brain responses to auditory stimulation during early adolescenceDEVELOPMENTAL SCIENCE, Issue 2 2009Catherine Poulsen Maturational changes in the capacity to process quickly the temporal envelope of sound have been linked to language abilities in typically developing individuals. As part of a longitudinal study of brain maturation and cognitive development during adolescence, we employed dense-array EEG and spatiotemporal source analysis to characterize maturational changes in the timing of brain responses to temporal variations in sound. We found significant changes in the brain responses compared longitudinally at two time points in early adolescence, namely 10 years (65 subjects) and 11.5 years (60 of the 65 subjects), as well as large differences between adults, studied with the same protocol (Poulsen, Picton & Paus, 2007), and the children at 10 and 11.5 years of age. The transient auditory evoked potential to tone onset showed decreases in the latency of vertex and T-complex components, and a highly significant increase in the amplitude of the N1 wave with increasing age. The auditory steady state response to a 40-Hz frequency-modulated tone increased in amplitude with increasing age. The peak frequency of the envelope-following response to sweeps of amplitude-modulated white noise also increased significantly with increasing age. These results indicate persistent maturation of the cortical mechanisms for auditory processing from childhood into middle adulthood. [source] Retinal capillary basement membrane thickness in diabetic mice genetically modified at the haptoglobin locusDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 2 2007Rachel Miller-Lotan Technion Faculty of Medicine Abstract Background Individuals with diabetes mellitus (DM) homozygous for the haptoglobin (Hp) 1 allele are at decreased risk of retinopathy as compared to DM individuals with the Hp 2 allele. We sought to recapitulate these findings in DM mice genetically modified at the Hp locus. Methods An early morphological characteristic of the microangiopathy seen in diabetic retinal disease is retinal capillary basement membrane (RCBM) thickening. RCBM thickness as assessed by electron microscopy was performed on a total of 12 eyes taken from three mice in each of the four study groups (three eyes from C57Bl/6 Hp 1 and C57Bl/6 Hp 2 mice with and without streptozotocin-induced diabetes). Results The non-parametric Kruskal,Wallis ANOVA test demonstrated that there was a highly significant difference between the four groups of mice (P < 0.0001). Mann,Whitney tests for specific pair-wise comparisons demonstrated that there was no significant difference in the RCBM thickness between Hp 1 and Hp 2 mice (p = 0.70) or between DM Hp 1 and non-DM Hp 1 mice (p = 0.42). However, induction of diabetes resulted in a marked increase in RCBM thickness in Hp 2 mice compared to non-DM Hp 2 mice (p = 0.0004) and compared to DM Hp 1 mice (p = 0.0005). Conclusions A highly significant increase in RCBM thickness was observed in DM mice with the Hp 2 genotype. These data provide important support for association studies done in humans showing an increased prevalence of diabetic retinopathy in individuals with the Hp 2 genotype. Copyright © 2006 John Wiley & Sons, Ltd. [source] Topical ascorbic acid on photoaged skin.EXPERIMENTAL DERMATOLOGY, Issue 3 2003Clinical, topographical, ultrastructural evaluation: double-blind study vs. placebo Abstract:, Vitamin C is known for its antioxidant potential and activity in the collagen biosynthetic pathway. Photoprotective properties of topically applied vitamin C have also been demonstrated, placing this molecule as a potential candidate for use in the prevention and treatment of skin ageing. A topically applied cream containing 5% vitamin C and its excipient were tested on healthy female volunteers presenting with photoaged skin on their low-neck and arms in view to evaluate efficacy and safety of such treatment. A double-blind, randomized trial was performed over a 6-month period, comparing the action of the vitamin C cream vs. excipient on photoaged skin. Clinical assessments included evaluation at the beginning and after 3 and 6 months of daily treatment. They were performed by the investigator and compared with the volunteer self assessment. Skin relief parameters were determined on silicone rubber replicas performed at the same time-points. Cutaneous biopsies were obtained at the end of the trial and investigated using immunohistochemistry and electron microscopy. Clinical examination by a dermatologist as well as self-assessment by the volunteers disclosed a significant improvement, in terms of the ,global score', on the vitamin C-treated side compared with the control. A highly significant increase in the density of skin microrelief and a decrease of the deep furrows were demonstrated. Ultrastructural evidence of the elastic tissue repair was also obtained and well corroborated the favorable results of the clinical and skin surface examinations. Topical application of 5% vitamin C cream was an effective and well-tolerated treatment. It led to a clinically apparent improvement of the photodamaged skin and induced modifications of skin relief and ultrastructure, suggesting a positive influence of topical vitamin C on parameters characteristic for sun-induced skin ageing. [source] Survival rates, causes of failure and productivity of Skylark Alauda arvensis nests on lowland farmlandIBIS, Issue 4 2002P. F. Donald This paper analyses data from 995 Skylark Alauda arvensis nests found on lowland farms in southern England from 1996 to 1998. The majority of recorded nest failures were caused by predation except in agricultural grass, where trampling and agricultural operations were equally important. Nest survival rates varied between crop types, nests in cereals being around twice as likely to succeed as nests in grass or set-aside. In cereals, nest survival rates increased with increasing distance from the nearest tramline and declined over the course of the breeding season. Predator control also had a significant independent effect on nest survival rates. On one farm where many other factors were held constant, a highly significant increase in nest survival rates from 12.3% to 40.7% coincided with the introduction of intensive predator control, which also appeared to bring forward mean laying dates. Most environmental factors explaining significant variation in nest survival rates did so only at the chick stage. The mean number of chicks produced per nesting attempt was 1.26 in cereals, 0.78 in set-aside and 0.63 in grass, the differences being due primarily to variation in nest survival rates. Low densities of Skylark territories in cereal crops are not therefore the consequence of low breeding success at the scale of the individual nest and probably reflect limitations on the number of attempts made in a season. Measures taken to improve the attractiveness of cereal crops as a nesting habitat for Skylarks, and beneficial changes in grassland management, are likely to increase overall productivity. [source] Albumin infusion fails to restore circulatory function following paracentesis of tense ascites as assessed by beat-to-beat haemodynamic measurementsINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 12 2008D. Schneditz Summary Aims:, To study whether circulatory changes during large volume paracentesis (LVP) in patients with liver cirrhosis and tense ascites as assessed by novel non-invasive haemodynamic measuring technology are reversed by subsequent albumin infusion. Materials and methods:, Eleven patients with portal hypertensive ascites secondary to liver cirrhosis of Child's class B or C were studied during LVP (10.7 ± 4.4 l) and subsequent infusion of albumin. Digital arterial pulse waves were continuously measured by vascular unloading technique providing data for beat-to-beat values of systolic (Ps), diastolic (Pd) and mean arterial pressures (Pm), respectively, as well as for heart rate (Fh), stroke volume (Vs), cardiac output (Qco) and peripheral resistance (R). Data extrapolated to the end of paracentesis, albumin infusion and follow-up phases were compared with the end of the equilibration phase. Results:, At the end of paracentesis, Ps, Pm and Pd changed by ,14 ± 15% (p < 0.05), ,16 ± 11% (p < 0.01) and ,17 ± 11% (p < 0.001), respectively, whereas Qco and Fh did not change substantially. There was a highly significant increase in Vs by +21 ± 25% (p < 0.01). The largest change was seen in R which significantly decreased by ,29 ± 24% (p < 0.01). This change was not reversed by infusion of albumin and persisted up to the end of follow-up. Conclusion:, The haemodynamic changes following LVP appear to be first and foremost controlled by changes in peripheral resistance with insufficient cardiac compensation. Further studies combining albumin with vasopressors for prevention of paracentesis-induced circulatory changes are needed. [source] Investigation into possible DNA damaging effects of ultrasound in occupationally exposed medical personnel , the alkaline comet assay studyJOURNAL OF APPLIED TOXICOLOGY, Issue 3 2005Verica Garaj-Vrhovac Abstract In the present paper the possible DNA damaging effects of ultrasound in occupationally exposed medical personnel were investigated using the alkaline comet assay. The extent of DNA migration in peripheral blood leucocytes was measured. Parameters of the comet assay were studied in 30 medical workers occupationally exposed to ultrasound and in 30 corresponding unexposed control subjects. It was found that the subjects who were occupationally exposed to ultrasound for various periods of time showed a highly significant increase in levels of DNA damage compared with the control. The results obtained have confirmed the usefulness of the alkaline comet assay as a sensitive biodosimetric method, reflecting the current level of DNA damage and[sol ]or repair in peripheral blood leucocytes of ultrasound-exposed subjects. In spite of their limitations, the results of the present investigation indicate that individuals occupationally exposed to ultrasound may experience an increased genotoxic risk, emphasizing the need for more research into the nature and extent of the biological consequences to medical personnel working with ultrasonic equipment. Copyright © 2005 John Wiley & Sons, Ltd. [source] Reversal of Electrical Remodeling After Cardioversion of Persistent Atrial FibrillationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2004MERRITT H. RAITT M.D. Introduction: In animals, atrial fibrillation results in reversible atrial electrical remodeling manifested as shortening of the atrial effective refractory period, slowing of intra-atrial conduction, and prolongation of sinus node recovery time. There is limited information on changes in these parameters after cardioversion in patients with persistent atrial fibrillation. Methods and Results: Thirty-eight patients who had been in atrial fibrillation for 1 to 12 months underwent electrophysiologic testing 10 minutes and 1 hour after cardioversion. At 1 week, 19 patients still in sinus rhythm returned for repeat testing. Reverse remodeling of the effective refractory period was not uniform across the three atrial sites tested. At the lateral right atrium, there was a highly significant increase in the effective refractory period between 10 minutes and 1 hour after cardioversion (drive cycle length 400 ms: 204 ± 17 ms vs 211 ± 20 ms, drive cycle length 550 ms: 213 ± 18 ms vs 219 ± 23 ms, P < 0.001). The effective refractory period at the coronary sinus and distal coronary sinus did not change in the first hour but had increased by 1 week. The corrected sinus node recovery time did not change in the first hour but was shorter at 1 week (606 ± 311 ms vs 408 ± 160 ms, P = 0.009). P wave duration also was shorter at 1 week (135 ± 18 ms vs 129 ± 13 ms, P = 0.04) consistent with increasing atrial conduction velocity. Conclusion: The atrial effective refractory period increases, sinus node function improves, and atrial conduction velocity goes up in the first week after cardioversion of long-standing atrial fibrillation in humans. Reverse electrical remodeling of the effective refractory period occurs at different rates in different regions of the atrium. (J Cardiovasc Electrophysiol, Vol. 15, pp. 507-512, May 2004) [source] CXCL12 chemokine up-regulates bone resorption and MMP-9 release by human osteoclasts: CXCL12 levels are increased in synovial and bone tissue of rheumatoid arthritis patientsJOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2004Francesco Grassi Chemokines are involved in a number of inflammatory pathologies and some of them show a pivotal role in the modulation of osteoclast development. Therefore, we evaluated the role of CXCL12 chemokine on osteoclast differentiation and function and we analyzed its expression on synovial and bone tissue biopsies from rheumatoid arthritis (RA) patients. Osteoclasts were obtained by 7 days in vitro differentiation with RANKL and M-CSF of CD11b positive cells in the presence or absence of CXCL12. The total number of osteoclast was analyzed by Tartrate-resistant acid phosphatase (TRAP)-staining and bone-resorbing activity was assessed by pit assay. MMP-9 and TIMP-1 release was evaluated by ELISA assay. CXCL12 expression on biopsies from RA patients was analyzed by immunohistochemistry. Osteoclasts obtained in the presence of CXCL12 at 10 nM concentration displayed a highly significant increase in bone-resorbing activity as measured by pit resorption assay, while the total number of mature osteoclasts was not affected. The increased resorption is associated with overexpression of MMP-9. Immunostaining for CXCL12 on synovial and bone tissue biopsies from both rheumatoid arthritis (RA) and osteoarthritis (OA) samples revealed a strong increase in the expression levels under inflammatory conditions. CXCL12 chemokine showed a clear activating role on mature osteoclast by inducing bone-resorbing activity and specific MMP-9 enzymatic release. Moreover, since bone and synovial biopsies from RA patients showed an elevated CXCL12 expression, these findings may provide useful tools for achieving a full elucidation of the complex network that regulates osteoclast function in course of inflammatory diseases. J. Cell. Physiol. 199: 244,251, 2004© 2003 Wiley-Liss, Inc. [source] Impact of changes in antigen level on CD38/PD-1 co-expression on HIV-specific CD8 T cells in chronic, untreated HIV-1 infection,,JOURNAL OF MEDICAL VIROLOGY, Issue 3 2010Thomas Vollbrecht Abstract Excessive immune activation is a hallmark of chronic uncontrolled HIV infection. During the past years, growing evidence suggests that immune inhibitory signals also play an important role in progressive disease. However, the relationship between positive and negative immune signals on HIV-specific CD8 T cells has not been studied in detail so far in chronic HIV-1 infection. In this study, the expression of markers of positive (CD38) and negative (PD-1) immune signals on virus-specific CD8 T cells in chronic, untreated HIV-1 infection was evaluated using intracellular cytokine staining. Viral escape mutations were assessed by autologous virus sequence analysis and subsequent peptide titration assays. Single-epitope CD8 T-cell responses toward Gag, Pol, and Nef were compared in 12 HIV-1 controllers (viral load <5,000,cp/ml) and 12 HIV-1 progressors (viral load >50,000,cp/ml) and a highly significant increase of CD38/PD-1 co-expression on virus-specific CD8 T cells in progressors was found (P,<,0.0001). The level of CD38/PD-1 co-expression was independent of epitope specificity. Longitudinal follow-up revealed a clear drop in CD38/PD-1 co-expression on virus-specific CD8 T cells after the suppression of antigen following either viral escape mutation or the initiation of HAART (P,=,0.004). Antigen persistence with a fluctuating viral load revealed stable levels of CD38/PD-1 co-expression whereas significant rises in viral load were accompanied or even preceded by substantial increases in CD38/PD-1 co-expression. The CD38/PD-1 phenotype clearly distinguishes HIV-specific CD8 T-cell responses between controllers and progressors. Whether it plays a causative role in disease progression remains debatable. J. Med. Virol. 82:358,370, 2010. © 2010 Wiley-Liss, Inc. [source] UNCOUPLING OF SILICON COMPARED WITH CARBON AND NITROGEN METABOLISMS AND THE ROLE OF THE CELL CYCLE IN CONTINUOUS CULTURES OF THALASSIOSIRA PSEUDONANA (BACILLARIOPHYCEAE) UNDER LIGHT, NITROGEN, AND PHOSPHORUS CONTROL1JOURNAL OF PHYCOLOGY, Issue 5 2002Pascal Claquin The elemental composition and the cell cycle stages of the marine diatom Thalassiosira pseudonana Hasle and Heimdal were studied in continuous cultures over a range of different light- (E), nitrogen- (N), and phosphorus- (P) limited growth rates. In all growth conditions investigated, the decrease in the growth rate was linked with a higher relative contribution of the G2+M phase. The other phases of the cell cycle, G1 and S, showed different patterns, depending on the type of limitation. All experiments showed a highly significant increase in the amount of biogenic silica per cell and per cell surface with decreasing growth rates. At low growth rates, the G2+M elongation allowed an increase of the silicification of the cells. This pattern could be explained by the major uptake of silicon during the G2+M phase and by the independence of this process on the requirements of the other elements. This was illustrated by the elemental ratios Si/C and Si/N that increased from 2- to 6-fold, depending of the type of limitation, whereas the C/N ratio decreased by 10% (E limitation) or increased by 50% (P limitation). The variations of the ratios clearly demonstrate the uncoupling of the Si metabolism compared with the C and N metabolisms. This uncoupling enabled us to explain that in any of the growth condition investigated, the silicification of the cells increased at low growth rates, whereas carbon and nitrogen cellular content are differently regulated, depending of the growth conditions. [source] Effect of Auxiliary Grooves on Molar Crown Preparations Lacking Resistance Form: A Laboratory StudyJOURNAL OF PROSTHODONTICS, Issue 2 2008DClinDent, GradDipClinDent, Po-Ching Lu BDSc(Hons) Abstract Purpose: To investigate the effect of auxiliary grooves on resistance to dislodgment of crowns on compromised molar preparations lacking resistance form. Materials and Methods: Thirty human molar teeth were randomly assigned to three groups of ten, and prepared to a height-to-width ratio of 0.3 with a total convergence of 50°, and 1-mm shoulder margin. Base metal alloy copings were constructed with a 45° loading platform and cemented with zinc phosphate cement under a 50 N load. Initially, resistance testing was conducted using a Universal Testing Machine (Instron) at 1 mm/min for all 30 specimens. Following crown dislodgment, Group 1 copings were recemented and retested, Group 2 had one axial groove added, and Group 3 had two axial grooves added. New copings for Groups 2 and 3 were made, cemented, and again tested for resistance. Standardized radiographs were taken prior to initial cementation and scanned into digital images. The percentage of area occupied by the pulpal chamber above the acrylic mounting (PS), and the closest distance to pulp from the preparation surface (CD) were measured. Results: Recementation or the addition of one groove did not affect the dislodgment values (p > 0.05), but addition of two grooves caused a highly significant increase in resistance (p < 0.001). Regression analysis showed an inverse relationship between initial resistance values and pulpal space area. Lower resistance values were observed when the pulpal space area was large (p= 0.004). Conclusions: Crowns can be recemented without affecting resistance to dislodgment. Two grooves should be incorporated into compromised molar crown preparations to increase resistance form. Teeth with large pulps and therefore less coronal dentine have poorer resistance form, and therefore would benefit from placement of auxiliary grooves. [source] Protein synthesis and mRNA storage in cattle oocytes maintained under meiotic block by roscovitine inhibition of MPF activityMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 4 2004Céline Vigneron Abstract Roscovitine, a specific inhibitor of MPF kinase activity, has been shown to block efficiently and reversibly the meiotic resumption of oocytes from different species, including cattle. In view to verify that oocytes maintain germinal vesicle like molecular activities under roscovitine treatment, we compared in the present study the M-phase Promoting Factor (MPF) and Mitogen Activated Protein (MAP) kinase activities; protein synthesis and phosphorylation patterns in oocytes and cumulus cells; and CDK1 and Cyclin B messengers storage under control culture and under roscovitine inhibition. We observed that roscovitine induced a full and reversible inhibition of MPF kinase activity and of the activating phosphorylation of both ERK1/2 MAPK. During in vivo maturation, there was a highly significant increase in the relative mRNA level of both cyclin B1 and CDK1 whereas during in vitro culture, the relative amount of CDK1 messenger was reduced. These messengers may be used as markers for the optimization of in vitro maturation treatment. Roscovitine reversibly prevented this drop in relative quantities of CDK1 messenger. Oocytes cultured in the presence of roscovitine maintained a GV like profile of protein synthesis except that two proteins of 48 and 64 kDa specific of matured oocytes also appeared under roscovitine treatment. However, roscovitine did not prevent most of the modifications of protein phosphorylation pattern observed during maturation. In conclusion, results of this study revealed that the use of roscovitine did not prevent all the events related to maturation of bovine oocytes. Mol. Reprod. Dev. 69: 457,465, 2004. © 2004 Wiley-Liss, Inc. [source] Improvement of reading speed after providing of low vision aids in patients with age-related macular degenerationACTA OPHTHALMOLOGICA, Issue 8 2009Nhung Xuan Nguyen Abstract. Purpose:, Age-related macular degeneration (AMD) is the most common cause of severe visual impairment, including loss of reading ability, among elderly persons in developed countries. The aim of the present study was to evaluate reading ability before and after providing of appropriate low vision aids. Methods:, Five hundred and thirty patients with different stages of AMD (age 82 ± 8 years) were included in this retrospective study. All patients underwent a standardized ophthalmological examination including evaluation of magnification requirement and careful providing of low vision aids. Before and after the provision of low vision aids, reading speed [words per minute (wpm)] was evaluated using standardized reading texts. Results:, For the whole group, the average best-corrected distance visual acuity of the better eye was 0.18 ± 0.15, with 69% of patients having visual acuity of 0.1 (20/200) or better. The mean magnification requirement was 7.4 ± 6.3-fold (range 2,25). Visual rehabilitation was achieved with optical visual aids in 58% of patients, whereas 42% of patients needed electronically closed-circuit TV systems. Mean reading speed was 20 ± 33 wpm before and increased significantly to 72 ± 35 (p < 0.0001) after the provision of low vision aids for the whole group. Between patients with visual acuity < 0.1 and patients with visual acuity of 0.1 or better, there are highly significant differences in reading speed before (0.4 ± 3.8 versus 20 ± 28 wpm, p , 0.0001) and after providing of visual aids (40 ± 13 versus 84 ± 30 wpm, p , 0.0001). Patients with severe visual impairment (visual acuity , 0.1) showed significantly lower improvement of reading speed compared to patients with visual acuity of 0.1 or better following rehabilitation (p , 0.0001). Before providing of low vision aids, only 16% of patients were able to read; in contrast, reading ability was achieved in 94% of patients after the provision of low vision aids for the whole group. Conclusion:, Our results indicate the great value of low vision rehabilitation through adequate providing of vision aids for the improvement of reading ability, with a highly significant increase of reading speed without training of eccentric viewing in patients with retained central fixation. The prompt implementation of low vision aids in patients with macular degeneration will help them to maintain and regain their reading ability, which can lead to an increase in independence, communication, mental agility and quality of life. [source] INVESTIGATION OF THE MICROCIRCULATION AND THE STATE OF OXIDATIVE STRESS IN THE RAT AFTER SCORPION ENVENOMATIONCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 4 2007Z Sahnoun SUMMARY 1Severe cases of scorpion envenomation (SE) generally show both respiratory and cardiocirculatory dysfunction. However, the pathophysiology of SE remains controversial. In the present study, we tried to explain the pathophysiology of the haemodynamic perturbations and cardiac failure in rats poisoned by the venom of Buthus occitanus tunetanus through a histomorphometric study of myocardial and muscular skeletal microcirculation and analysis of the oxidative stress state in order to evaluate the implication of the inflammatory process in the pathogenesis of SE. 2Experiments were performed on 96 rats divided into 16 groups (n = 6 in each group). Two groups were used to determine the optimum conditions of venom administration and times when to measure haemodynamic parameters. The B. occitanus tunetanus venom was administered at a dose of 800 µg/kg and tissues were removed 5 and 20 min after envenomation. Six groups were used for histomorphometric study: two control groups, two poisoned groups an two melatonin-pretreated and poisoned groups. The histomorphometric study was performed on isolated hearts and skeletal muscles. The final eight groups of rats (two control groups, two envenomated groups, two control groups pretreated with melatonin and two groups pretreated and envenomated) were used to investigate the state of tissue oxidative stress during SE and to evaluate the anti-oxidant effect of melatonin on rats poisoned with B. occitanus tunetanus venom. This study was based on the determination of tissue malondialdehyde in isolated organs as an indicator of thiobarbituric acid-reactive substances (TBARS). Melatonin was injected at a dose of 5 mg/kg, i.v., 15 min before the administration of serum or venom. Data were compared using analysis of variance and Tukey's test for multiple pair-wise comparisons. 3Five minutes after venom injection, a significant reduction in the mean relative volume of venules and arterioles in the heart and skeletal muscles of poisoned rats was noted. Twenty minutes after venom injection, these volumes were significantly increased in the heart and skeletal muscles of poisoned rats. Pretreatment of envenomated rats with melatonin resulted in a significant decrease in the mean relative volume of the venules and arterioles in the heart and skeletal muscles 5 and 20 min after venom injection compared with untreated envenomated rats. Investigation of the oxidative stress state showed a highly significant increase in TBARS in poisoned rats compared with control groups 5 and 20 min after venom injection. Melatonin pretreatment of rats poisoned with B. occitanus tunetanus venom resulted in an important and highly significant reduction of TBARS compared with untreated envenomated rats. 4It appears from the results of the present study that administration of B. occitanus tunetanus venom engendered an excessive myocardial and skeletal muscular vasoconstriction attributed to massive catecholamine release followed by arteriolar and venular vasodilatation. This venous stasis at the muscular microcirculation could be due to myocardiac failure. However, the concomitant presence of arteriolar vasodilatation suggests an inflammatory process in the pathophysiology of SE. This process was suggested by the genesis of a state of oxidative stress in relation to the important lipoperoxidation, which was inhibited by administration of the anti-oxidant melatonin. Thus, melatonin pretreatment seemed to accentuate the first phase of vascular reactivity in envenomed rats and inhibit the second vasodilator phase observed 20 min after administration of the venom. [source] Testing the effect of including oral health in general health checks for elderly patients in medical practice , a randomized controlled trialCOMMUNITY DENTISTRY AND ORAL EPIDEMIOLOGY, Issue 1 2007C. Lowe Abstract,,, Aim:, To test the feasibility and effectiveness of an oral health referral process for elderly patients (aged 75 years or over) attending a preventive health check (PHC) with their general medical practitioner. Objectives:, To evaluate the effectiveness of the process in increasing dental attendance at baseline and 6 months after the intervention. To identify key characteristics of those who accepted an oral health visit (OHV). To determine the proportion of people attending the OHV who required treatment and subsequently attended a dentist. Setting:, Three general medical practices in east Cheshire, UK. Design:, A randomized controlled trial. Method:, Elderly patients attending their general medical practice for PHCs were randomly assigned to a test group, who were invited to attend for an OHV, and to a control group, who received no intervention. Six months after the PHC the effectiveness of the process was measured. Results:, Some 50% of those invited for an OHV accepted. Those accepting were more likely to be edentulous, wear dentures or have a current oral health problem, than those declining. Regression analysis showed the best predictors of acceptance to be having a current dental problem or pain and not having a regular dentist. The mean time since their last dental visit was 8.1 years which was significantly longer than those declining the OHV. 63% of individuals attending the OHV were assessed as having a realistic treatment need and 70% of those referred went on to complete the course of treatment. In the test group a highly significant increase in reported dental visiting was found at sixth month evaluation. The primary care staff were happy to include the dental checklist and felt it was a valuable addition to the PHC. Conclusions:, The offer of an OHV was taken up most readily by those with current oral problems, or pain and those with no regular dentist. The inclusion of a dental checklist within the PHC for elderly patients together with help with arranging a dental appointment shows promise as a way of ensuring the dental needs of this group are met. [source] | |||||||||||||