Hepatoprotective effects of diethylcarbamazine in acute liver damage induced by carbon tetrachloride in rats

This research was carried out to determine a potential role of leukotrienes in the acute hepatotoxicity induced by CC14 in rats. An inhibitor of leukotrienes biosynthesis, diethylcarbamazine (DEC, 25 and 50 mg ·kg-1 ip) exerted hepatoprotective effects, decreasing the activity of alanine aminotransfer-ase in serum and the concentration of liver triglycerides. DEC reduced histological damage of liver evidenced by electron microscopy. The hepatoprotective effects of DEC were dose-dependent. The results favor the role of leukotrienes in CC14 hepatotoxicity.     

Global environmental change: preventive measures to reduce the impact on human health

Awareness of the magnitude of worldwide climate change and theloss of biological diversity that may occur as the result ofpresent human activities is increasing. However, much needsto be done to reverse current trends and prevent unprecedentedglobal environmental changes which are expected to produce irreversibleresults, and to have profound implications for the health ofindividuals. This paper briefly reviews what is known aboutthe global environmental changes that are taking place and theirpredicted impact on human health. Some of the preventive measuresand activities in which public health professionals need toassume leadership roles in the critical years ahead are discussed.Our hope is to enliven a much needed dialogue among health professionalson the crucial issue of environmental survival in which preventionmay be the only viable solution.     

PGE1 abolishes the mitochondrial-independent cell death pathway induced by D-galactosamine in primary culture of rat hepatocytes

Background and Aim:  PGE₁ reduces in vivo and in vitro D-galactosamine (D-GalN)-induced cell death in hepatocytes. The present study was undertaken to elucidate the intracellular pathway by which D-GalN induces cell death in cultured hepatocytes. In addition, we evaluated if PGE₁ was able to modulate different parameters related to D-GalN-induced apoptosis in cultured rat hepatocytes.
Methods:  Hepatocytes were isolated from male Wistar rats (225–275 g) by the classical collagenase procedure. PGE₁ (1 µM) was administered 2 h before D-GalN (5 mM) in primary culture of rat hepatocytes. Apoptosis was determined by DNA fragmentation and caspase-3, -6, -8 and -9 activation in hepatocytes. Caspase activation was evaluated by the detection of the related cleaved product and its associated activity. Cell necrosis was determined by the measurement of lactate dehydrogenase (LDH) activity in culture medium. To elucidate the role of mitochondria, we measured neutral (nSMase) and acid (aSMase) sphingomyelinase, as well as the expression of cytochrome c in mitochondria and cytoplasm fractions from D-GalN treated hepatocytes.
Results:  D-GalN induced caspase-3 activation and DNA fragmentation in hepatocytes. This apoptotic response was not associated with the activation of caspase-6, -8 or -9. The use of specific inhibitors confirmed that only caspase-3 was involved in D-GalN-induced apoptosis. D-GalN did not modify nSMase and aSMase activities, nor mitochondrial cytochrome c release in hepatocytes.
Conclusions:  D-GalN induced apoptosis through caspase-3 activation but without modification of the activity of caspase-6, -8, -9, SMases or cytochrome c release. PGE₁ appears to prevent D-GalN-induced apoptosis by a mitochondria-independent mechanism.     

Concept Mapping: An Effective Instructional Strategy for Diet Therapy

Concept mapping is an instructional strategy that requires learners to identify, graphically display, and link key concepts in instructional reading material. Although proven effective in numerous disciplines as a means to promote critical thinking and self-directed learning, concept mapping has not been tested in diet therapy. The objective of this study was to implement concept mapping as a small-group, cooperative learning strategy in an upper-division diet therapy course and to evaluate student attitudes about the effect of concept mapping on knowledge, self-directed learning, problem-solving, and collaborative skills. Students in the first semester (n=27) initially learned course material by lecture (4 weeks) followed by an integrated mapping/lecture format (12 weeks); the second semester (n=25) used an integrated mapping lecture format for the full 16 weeks. At the end of both semesters, students completed a 10-item original survey questionnaire. Responses for first (n=25) and second (n=21) semesters were analyzed independently. Results indicated that a majority of students thought participation in concept mapping enhanced knowledge of diet therapy principles (n=19 of 25; 18 of 21), self-directed learning (n=14 of 25; 18 of 21), critical thinking (n=21 of 25; 14 of 21), problem-solving (n=22 of 25; 16 of 21), and collaboration (n=24 of 25; 20 of 21) skills. When noncooperation of teammates was a factor, concept mapping was viewed as more frustrating and time consuming than lecture. This study demonstrated concept mapping as an effective learning strategy for diet therapy; it improves students’ ability to engage in self-directed learning, critical thinking, collaboration, and creative problem solving. Results suggest that concept mapping is most effective when accompanied with comprehensive training, coordinated lectures, instructor guidance, and long-term practice. J Am Diet Assoc. 1995; 95:908–911.     

Increased Kidney Glucose Utilization Induced by Cyclosporine:Lack of Relation to Magnesium Excretion

Increased Kidney Glucose Utilization Induced by Cyclospone:Lack of Relation to Magnesium Excretion. BOROWITZ, J. L, MAYER,P. R., RODRIGUEZ, C A., AND ANTOUN, M. (1989).Fundam. Appl Toxicol12, 158–162. Cyclosporine enhances D-[5-³H]glucose utilizationin homogenates of rat kidney medulla but not kidney cortex orliver. This is true whether cyclosporine is added to fresh tissuehomogenates or is given to rats prior to sacrifice. Throughthe use of isolated perfused rat kidneys, an attempt was madeto relate increased glucose utilization by cyclosporine to apossible consequence of cyclosponne nephrotoxicity, viz., lossof magnesium in urine. Although an enhanced rate of glucoseutilization by cyclosporine was evident in isolated kidneys,glucose consumption was not related to urinary magnesium loss.In fact, kidneys from cyclosporine-treated rats actually showeda normal or even diminished urinary magnesium loss. The datasuggest that cyclosporine-induced magnesium imbalance may beextrarenal in origin and that the kidney medulla may be a primarysite of the nephrotoxic action of cyclosporine since the drugincreases glucose utilization at this site.     

A functional and clinical reinterpretation of human perineal neuromuscular anatomy: Application to sexual function and continence

Modern anatomical and surgical references illustrate perineal muscles all innervated by branches of the pudendal nerve but still organized into anatomically distinct urogenital and anal triangles with muscles inserting onto a central perineal body. However, these conflict with the anatomy commonly encountered during dissection. We used dissections of 43 human cadavers to characterize the anatomical organization of the human perineum and compare our findings to standard references. We found bulbospongiosus and the superficial portion of the external anal sphincter (EAS) were continuous anatomically with a common innervation in 92.3% of specimens. The superficial transverse perineal muscle inserted anterior and lateral to the midline, interdigitating with bulbospongiosus. The three EAS subdivisions were anatomically discontinuous. Additionally, in 89.2% of our sample the inferior rectal nerve emerged as a branch of S3 and S4 distinct from the pudendal nerve and innervated only the subcutaneous EAS. Branches of the perineal nerve innervated bulbospongiosus and the superficial EAS and nerve to levator ani innervated the deep EAS. In conclusion, we empirically demonstrate important and clinically relevant differences with perineal anatomy commonly described in standard texts. First, independent innervation to the three portions of EAS suggests the potential for functional independence. Second, neuromuscular continuity between bulbospongiosus and superficial EAS suggests the possibility of shared or overlapping function of the urogenital and anal triangles. Clin. Anat. 29:1053–1058, 2016. © 2016 Wiley Periodicals, Inc.     

Retention of dental sealants placed on sound teeth and incipient caries lesions as part of a service‐learning programme in rural areas in Mexico

International Journal of Paediatric Dentistry 2012; 22: 451–458 Background. Dental sealants are an effective treatment for the prevention and management of caries. Objective. To determine the retention of sealants placed in a rural setting in Mexico as part of an international service‐learning (ISL) programme and to determine associations between dental sealant’s retention and caries diagnosis at the time of sealant placement. Methods. Children aged 6–15 were examined for dental caries, received sealants by dental students as part of an ISL programme, and were re‐examined 4, 2, or 1 years after placement to assess sealant survival. Sealants were placed on permanent sound surfaces and enamel caries lesions [International Caries Assessment and Detection System (ICDAS) criteria]. Sealant survival was explored using Cochran–Mantel–Haenszel tests and multivariate prediction models. Results. 219 (46%) of 478 (mean age = 10.53 SD = 5.11) children who had received sealants returned for a recall examination (mean age = 10.89 SD = 3.11). After 1–4 years, 96.4% to 60.6% of the sealants placed on sound teeth had survived, and for sealants placed on surfaces with enamel caries lesions (ICDAS 1–3), 94.2% to 55.6% had survived. Differences were not statistically significant. Conclusions. Sealants had survival rates comparable to those previously reported in the literature. Sealants placed on sound and enamel caries lesions had similar survival rates.     

Echocardiographic wall motion abnormalities and the signal averaged electrocardiogram in the acute phase of a first myocardial infarction

We studied the relationship between wall motion abnormalitiesdetermined by echocardiography and the signal-averaged electrocardiogramin 82 consecutive patients during the acute phase of a firstmyocardial infarction. An abnormal signal-averaged electrocardiogramwas defined as the presence of two of the following criteria:a QRS duration 114 ms, a root mean square voltage (RMS) ofthe last 40 ms 25 µV and an amplitude signal lower than40µV lasting 39 ms. The left ventricle was divided into13 segments and the contraction pattern divided into akinesiaalone (including dyskinesia) (group A), hypokinesia alone (groupB) and both hypokinesia and akinesia (group C). An abnormal signal-averaged electrocardiogram was found in 14/82patients (17%) and was correlated with the persistence of occlusionof the infarct-related vessel (32% vs 9%. P < 0.02). In patientswith a patent vessel, the incidence of an abnormal signal-averagedelectrocardiogram was 14% in group A, 9% in group B and 0% ingroup C (NS). In patients with an occluded vessel an abnormalsignal-averaged electrocardiogram was found in 10% of groupA patients, in 36% in group B patients and in 75% of group Cpatients (P = 0.05). Our study suggests that the presence of hypokinetic areas duringthe acute phase of a first myocardial infarction and an abnormalsignal-averaged electrocardiogram indicate an occluded infarct-relatedvessel.