Electrophysiological characterization of left ventricular myocytes from obese Sprague-Dawley rat

Objective: Obesity is a complex multifactorial disease that is often associated with cardiac arrhythmias. Various animal models have been used extensively to study the effects of obesity on physiological functions, but, to our knowledge, no study related to ionic membrane currents has been performed on isolated cardiac myocytes. Therefore, we examined the electrophysiological characteristics of four ionic currents from isolated left ventricular myocytes of a high‐energy (HE)‐induced obesity rat model. Research Methods and Procedures: Male Sprague‐Dawley rats were fed with either a control diet or a diet containing 33% kcal as fat (HE) for 14 weeks starting at 6 weeks of age. Voltage‐clamp experiments were performed on ventricular myocytes. Leptin receptor (ObR) expression was measured using ObR enzyme‐linked immunosorbent assay. Results: In the HE group, rats designated as obese did not develop a cardiac hypertrophy, either at the organ level or at the cellular level. Densities and kinetics of the L‐type calcium current, the transient outward potassium current, the delayed rectifier potassium current, and the sodium‐calcium exchange current (I_NCX) were not significantly different between control and obese rats. A down‐regulation of ObR expression was evidenced in the heart of obese rats compared with controls. Acute exposure (5 minutes) of leptin (100 nM) did not induce a significant modification in the current densities either in control or in obese rats, except for I_NCX density measured in control rats. Discussion: The absence of effect of leptin on I_NCX in obese rats could be a potential arrhythmogenic substrate in obesity.     

Freshwater fish diversity in Algeria with emphasis on alien species

Little is known about freshwater fish diversity in Algeria, especially after the broad national program of introduction of exotic species applied for over 20 years. This paper is an attempt to describe the current situation emphasizing the characteristics of the various introductions of non-autochthonous species, their current status and their possible impacts. The freshwater fish fauna of Algeria is composed of 48 species belonging to 15 families. Twenty-one species are autochthonous, of which, three are endemic (Haplochromis desfontainii, Aphanius saourensis, Aphanius apodus), two are endangered (H. desfontainii, Aphanius iberus), and one is critically endangered (Anguilla anguilla). Twenty-seven species were introduced, of which, 18 never became established and 9 are established. Four species are reported for the first time: Abramis brama, Aspius aspius, Carassius carassius, Perca fluviatilis. Since 1860, 303 introduction events have been recorded at almost 107 different sites in Algeria. The number of introduction events per site was between 1 and 10. Most of the introduced fish are found in Oubéïra Lake (seven species). Aquaculture development was the main reason for fish introductions (37.0%). The five most often introduced species were Cyprinus carpio (86 records), Hypophthalmichthys molitrix (65 records), Aristichthys nobilis (51 records), Oreochromis niloticus niloticus (33 records), and Ctenopharyngodon idella (18 records). Since the adverse effects of introduced fish are risky and demonstrated in several countries, the adoption of the precautionary principle is recommended when new introductions are planned. It is important, therefore, to adopt regulations and procedures which will minimize the risks arising from introductions.     

Ultrastructural characters of the spermatozoon of the digenean Hypocreadium caputvadum Kacem et al., 2011 (Lepocreadioidea: Lepocreadiidae), an intestinal parasite of Balistes capriscus in Tunisia

The ultrastructural organization of the spermatozoon of the digenean Hypocreadium caputvadum (Lepocreadioidea: Lepocreadiidae) is described. Live digeneans were collected from Balistes capriscus (Teleostei: Balistidae) from the Gulf of Gabès, Tunisia (Eastern Mediterranean Sea). The mature spermatozoon of H. caputvadum shows several ultrastructural characters such as two axonemes of different lengths exhibiting the classical 9 + “1” trepaxonematan pattern, a nucleus, two mitochondria, granules of glycogen, external ornamentation of the plasma membrane and two bundles of parallel cortical microtubules. Moreover, in the anterior extremity, the second axoneme is partly surrounded by a discontinuous and submembranous layer of electron-dense material. Our study provides new data on the spermatozoon of H. caputvadum in order to improve the understanding of phylogenetic relationships in the Digenea, particularly in the superfamily Lepocreadioidea. In this context, the electron-dense material surrounding one of the axonemes in the anterior spermatozoon extremity constitutes the unique distinguishing ultrastructural character of lepocreadioideans, and it is present in spermatozoa of lepocreadiids, aephnidiogenids and gyliauchenids.     

Managing the risk of cancer in Cowden syndrome: a case report

ABSTRACT: INTRODUCTION: Cowden syndrome is a rare cancer predisposition syndrome inherited in an autosomaldominantfashion. The syndrome is characterized by hamartomatous polyps that affectmultiple organs: skin, mucous membranes, thyroid, breast, gastrointestinal tract,endometrium and brain. It is also associated with an increased risk of developing malignancyin many tissues but especially breast, thyroid and endometrium. CASE PRESENTATION: We present the case of a 30-year-old Tunisian woman with mental retardation who presentedto our facility with rectal hamartomatous polyps. Her medical history included fibrocysticdisease of the breast over the last three years. A physical examination revealed macrocephaly,hyperkeratotic papules on the mid-facial skin, palmoplantar keratosis and oral mucosalpapillomatosis. A breast examination revealed nodular breast tissue bilaterally and a diffusethyroid goiter. Our patient was clinically euthyroid. A total thyroidectomy was performed. Ahistopathologic examination revealed thyroid papillary carcinoma. A gastrointestinalevaluation revealed esophageal and gastric polyps. Biopsies showed hyperplastic andadenomatous lesions associated with Helicobacter pylori. A final diagnosis of Cowdensyndrome was made according to the syndrome testing criteria adapted by the US NationalComprehensive Cancer Network. A prophylactic bilateral mastectomy was proposed butrefused by our patient. Our patient was kept under surveillance for breast and colorectalmalignancies. CONCLUSIONS: Early and accurate diagnosis of Cowden syndrome is essential because it is a cancerpredisposition syndrome that carries an increased risk for developing malignancy in manytissues, especially breast and thyroid. For this reason, education regarding the signs andsymptoms of cancer is important. All patients must be screened for malignancies and optionsfor prophylactic mastectomy should be discussed. Guidelines for cancer screening includingsurveillance and management plans for these patients should be distinguished from those ofthe general population, and may lead to a more timely diagnosis and treatment of cancersassociated with this syndrome.     

Molecular evidence of conspecificity of South African hares conventionally considered Lepus capensis L., 1758

Conventionally, Lepus capensis is considered to range across large parts of Africa, the Middle East, Central and Far East Asia. However, a recent morphological study restricts cape hares tentatively to a small range in the Western Cape Region of South Africa and groups all other L. capensis-type hares from South Africa into a new species: L. centralis. Here, we studied molecular relationships among L. capensis-type hares from South Africa. Phenotypically and morphologically the individuals matched either the newly described L. capensis or L. centralis. We examined 66 hares for allelic variation at 13 microsatellite loci and for sequence variation of the hypervariable domain 1 of the mitochondrial control region. All tree-generating analyses of the currently obtained sequences and all South African cape hare sequences downloaded from GenBank revealed monophyly when compared to sequences of various other Lepus species. A network analysis indicated close evolutionary relationships between hares of the “L. capensis-phenotype” and the “L. centralis-phenotype” (according to Palacios et al. 2008) from the southwest of the Western Cape, relative to their pronounced evolutionary divergence from all other more central, northern, and north-eastern L. capensis-type hares. F-statistics, a Bayesian admixture STRUCTURE model, as well as a principal coordinate analysis of microsatellite data indicated close genetic relationships among all South African L. capensis-type hares studied presently. A coalescence model-based migration analysis for microsatellite alleles indicated gene flow between most of the considered subspecies of cape hare, including L. capensis capensis and L. capensis centralis, theoretically sufficient to balance stochastic drift effects. Concordantly, AMOVA models revealed only little effects of partitioning microsatellite variation into the two suggested morpho-species “L. capensis” and “L. centralis”. Under an “Interbreeding Species Concept” (e.g. a strict or relaxed Biological Species Concept), the current molecular data demonstrate conspecificity of the two proposed morpho-species “L. capensis” and “L. centralis”. Based on the present molecular data the differentiation of subspecies of cape hares from southern Africa is discussed.     

Effects of salt stress on photosynthesis,PSII photochemistry and thermal energy dissipation in leaves of two corn (<Emphasis Type="Italic">Zea mays</Emphasis> L.) varieties

The effect of four different NaCl concentrations (from 0 to 102 mM NaCl) on seedlings leaves of two corn (Zea mays L.) varieties (Aristo and Arper) was investigated through chlorophyll (Chl) a fluorescence parameters, photosynthesis, stomatal conductance, photosynthetic pigments concentration, tissue hydration and ionic accumulation. Salinity treatments showed a decrease in maximal efficiency of PSII photochemistry (F_v/F_m) in dark-adapted leaves. Moreover, the actual PSII efficiency (ϕ_PSII), photochemical quenching coefficient (q_p), proportion of PSII centers effectively reoxidized, and the fraction of light used in PSII photochemistry (%P) were also dropped with increasing salinity in light-adapted leaves. Reductions in these parameters were greater in Aristo than in Arper. The tissue hydration decreased in salt-treated leaves as did the photosynthesis, stomatal conductance (g _s) and photosynthetic pigments concentration essentially at 68 and 102 mM NaCl. In both varieties the reduction of photosynthesis was mainly due to stomatal closure and partially to PSII photoinhibition. The differences between the two varieties indicate that Aristo was more susceptible to salt-stress damage than Arper which revealed a moderate regulation of the leaf ionic accumulation.     

Sesquiterpenoids from Teucrium ramosissimum

An antiplasmodial bioguided investigation of the EtOAc extract of the aerial parts of Teucrium ramosissimum led to isolation and identification of three sesquiterpenoids, teucmosin, 4α-hydroxy-homalomenol C, 1β,4β,7α-trihydroxy-8,9-eudesmene and two trinorsesquiterpenoids, 4β-hydroxy-11,12,13-trinor-5-eudesmen-1,7-dione and 1β,4β-dihydroxy-11,12,13-trinor-8,9-eudesmen-7-one together with five known sesquiterpenoids, oplopanone, homalomenol C, oxo-T-cadinol, 1β,4β,6β-trihydroxyeudesmane, 1β,4β,7α-trihydroxyeudesmane and four flavonoids, 5-hydroxy-7,4′-dimethoxyflavone, salvigenin, genkwanin and cirsimaritin. The structures and the relative stereochemistry were elucidated by extensive spectroscopic studies including 1D and 2D NMR and mass spectrometry (MS). Homalomenol C, 4β-hydroxy-11,12,13-trinor-5-eudesmen-1,7-dione, oxo-T-cadinol and 1β,4β,6β-trihydroxyeudesmane displayed a significant in vitro antiplasmodial activity against Plasmodium falciparum with IC₅₀ values ranging from 1.2 to 5.0 μg/ml. Furthermore, no cytotoxicity was observed upon the human diploid lung cell line MRC-5 for these compounds.     

Chemical Composition and In Vitro Evaluation of Antimicrobial,Antioxidant and Antigerminative Properties of the Seed Oil from the Tunisian Endemic Ferula tunetana Pomel ex Batt.

Essential oil of the seeds from the endemic Tunisian plant Ferula tunetana Pomel ex Batt . was analyzed for its chemical composition and screened for its antimicrobial, antioxidant and antigerminative properties. The chemical composition of the isolated oil is reported for the first time. According to the GC/FID, GC/MS and ¹³C‐NMR analysis results; 18 compounds were identified accounting for 84.6% of the total oil. The chemical composition of this essential oil was characterized by the presence of a high proportion of monoterpene hydrocarbons (77.3%) followed by oxygenated sesquiterpenes (4.1%) and sesquiterpene hydrocarbons (3.2%). α‐Pinene (39.8%), β‐pinene (11.5%) and (Z)‐β‐ocimene (7.5%) were the predominant compounds. Moreover, the isolated oil was tested for its antimicrobial activity using the disc‐diffusion and the microdilution assays against six Gram‐positive and five Gram‐negative bacteria as well as towards two Candida species. The isolated oil was tested also for its antioxidant activity against DPPH, ABTS, and hydrogen peroxide (H₂O₂), and for its antigerminative potential. It was found that it exhibited interesting antimicrobial activity against Salmonella typhimurium LT2 DT104 (inhibition zone (IZ) 16.2 ± 1.0 mm) and Bacillus cereus ATCC 14579 (IZ 15.8 ± 1.0 mm). However, it exerted a moderate antioxidant activity against H₂O₂ (IC₅₀ 78.2 ± 2.98 μg/ml) and towards (IC₅₀ 89.2 ± 3.82 μg/ml). The antigerminative effect of this oil was also evaluated in this work. Results showed a toxic effect.     

The hand of man first then Santa Rosalia’s blessing: a critical examination of the supposed criticism by Samraoui (2017)

Samraoui (J Insect Conserv.  https://doi.org/10.1007/s10841-017-9966-2, 2017) claims that he shows evidence that our conservation plan of Urothemis edwardsii has failed and that natural dispersal was the only cause of the recent rapid range expansion of the species in Northeast Algeria. Here, we show that his analysis is biased, many of his arguments are erroneous and strongly contradictory, many key studies are dismissed, and the few data used as evidence to refute our conclusions rather confirm them. We also provide data to prove that our conservation plan did not cause any harm to the source population by comparing exuviae-based estimation of population size in 2012 and 2016. We discuss the need for future monitoring and management and highlight that the recommendations of Samraoui (J Insect Conserv, 2017) are misleading, and thus are unlikely to bring us closer to an effective long-term conservation of the species in the region. Beyond our criticism, we explain why we should not dismiss the direct and indirect implications of final instar larvae translocation in successful colonization of odonates in particular, which could also be applied to aquatic insects in general.     

Effect of Ramadan on the diurnal variation in short-term high power output

This study examined the effects of Ramadan fasting on anaerobic performances and their diurnal fluctuations. In a balanced and randomized study design, 12 subjects were measured for maximal power (P_max; force-velocity test), peak power (P_peak), and mean power (P_mean) with the Wingate test at 07:00, 17:00, and 21:00 h on four different occasions: one week before Ramadan (BR), the second week of Ramadan (SWR), the fourth week of Ramadan (ER), and two weeks after Ramadan (AR). There was an interval of 28 h between any two successive tests. Oral temperature was measured before each test. Under each condition, the results showed a time-of-day effect on oral temperature. Analysis of variance revealed a significant (Ramadan×time-of-day of test) interaction effect on P_max. This variable improved significantly from morning to evening before Ramadan (1.1±0.2 W · kg^-1), during the second week of Ramadan (0.6±0.2 W · kg^-1), and two weeks after the end of Ramadan (0.9±0.2 W · kg^-1). However, daily fluctuations disappeared during the fourth week of Ramadan. For P_peak and P_mean, there was no significant Ramadan×test-time interaction. These variables improved significantly from morning to evening before Ramadan ([1±0.3 W · kg^-1] for P_peak and [1.7±1.6 W · kg^-1] for P_mean) and in the second week of Ramadan ([0.9±0.6 W · kg^-1] for P_peak and [1.7±1.5 W · kg^-1] for P_mean). However, they were not affected by time-of-day in the fourth week of Ramadan. Considering the effect of Ramadan on anaerobic performances, in comparison with before Ramadan, no significant difference was observed during Ramadan at 07:00 h. The variables were significantly lower in the second week of Ramadan and in the fourth week of Ramadan at 17:00 h and 21:00 h. P_mean was not affected during the second week of Ramadan. In conclusion, the time-of-day effect on anaerobic power variables tends to disappear during Ramadan. In comparison with the period before Ramadan, anaerobic performances were unaffected in the morning but impaired in the evening during Ramadan.