Evaluation des effets de l’extrait aqueux des fleurs de Nymphaea lotus Linn. (Nymphéacées) sur la fonction de reproduction des rats normoglycémique et diabétique de type 1

In traditional medicine of Cameroon, Nymphaea lotus Linn. (Nympheaceae) is used for treatment of male sexual disorders. The aim of this study was to evaluate the effects of the N. lotus flowers aqueous extracts on general mating behavior, fertility and some androgenic parameters of normoglycemic and diabetic adult male rats. Mating behavior assessment was carried out with primiparous and with oestrus female rats. Male rats were divided into 5 groups and subjected once in a day to the following treatment: distilled water (10 mL/kg), Sildenafil citrate (5mg/kg), Testosterone enanthate (5mg/kg) and plant extract (75 mg/kg and 150 mg/kg). Treatment lasted for 8 and 55 days before sacrifice. Organ weight, epididymal sperm counts, motility, viability, histomorphometric analysis, muscular strength, seminal fructose, cholesterol level, epididymal and serum proteins testicular were determined. Results showed a dose- dependant influence of the treatment in sperm count and motility which significantly increases compared to the distilled water-administered control. An increase in some sexual performance parameters (mount and intromission frequencies) was observed in both diabetic and normal rats compared to respective controls. The latencies of mount and intromission were significantly reduced. Computed frequencies of penile licking, index of libido and sexual motivation were higher in normal and diabetic extract-treated animals; which suggest an enhancement of motivational parameters. The treatment also caused significant increases in the weight of the testis, prostate, epididymis, in serum cholesterol and epididymal protein level in normal rats compared to the distilled water-administered control. These results indicate an androgenic pro-sexual potential of N. lotus in male rats and justify the empirical use of N. lotus in the management of erectile dysfunction and fertility disorders in males. Key-words: Nymphaea lotus, prosexual, androgenic, fertility, diabetic, male rat. //Selon les tradipraticiens de l’Ouest-Cameroun, Nymphaea lotus Linn. (N. lotus), de la famille des Nymphéacées, est utilisé pour le traitement des dysfonctionnements sexuels chez les hommes. Dans cette étude, l’effet de l’extrait aqueux des fleurs de N. lotus sur la fonction de reproduction des rats mâles adultes normaux et diabétiques a été évalué. Dans le but d’évaluer les effets de l’extrait aqueux des fleurs de N. lotus sur les paramètres généraux de copulation, d’androgénicité et de fertilité, les rats normoglycémiques et diabétiques ont été divisé en 3 groupes contrôle [Groupe I- recevant de l’eau distillée, Groupe II et III recevant respectivement du citrate de sildénafil (5 mg/kg) et l’énanthate de testostérone (5 mg/kg)] et deux groupes expérimentaux traités à l’extrait aux doses 75 mg/kg (Groupe IV) et 150 mg/kg (Groupe V). L’eau distillée, l’extrait et la substance de référence était administré per os une fois par jour. Pour analyser le comportement sexuel et la fertilité, des femelles primipares et en oestrus étaient utilisées. Le traitement a duré 8 et 55 jours avant le sacrifice. Le poids relatif des organes, le nombre de spermatozoïde, la motilité, les analyses morphométriques, la force musculaire, le taux de cholestérol, le taux de protéines sériques et épididymaires étaient déterminé. Le temps de latence de monte et d’intromission a diminué significativement alors que la fréquence d’éjaculation a augmenté. L’index de libido, la fréquence de monte, d’intromission, d’éjaculation, d’orientation des mâles vis-à-vis d’eux même et l’index de motivation sexuelle a augmenté chez les animaux traités l’extrait comparés à ceux ayant reçu de l’eau distillée aussi bien chez les normaux que chez le diabétiques qui n’enregistrent d’ailleurs aucune éjaculation. Le traitement a augmenté significativement (P < 0,01) le poids des testicules, de la prostate et de l’épididyme. Il est observé une augmentation dose-dépendante du nombre et de la motilité des spermatozoïdes (P < 0,05), ainsi qu’une augmentation significative (P < 0,001) temps-dépendant du taux de cholestérol sérique et de protéines épididymaires. Ces résultats indiquent un potentiel androgénique pro-érectile de N. lotus chez les rats mâles et justifient l’utilisation empirique des fleurs de N. lotus dans le traitement des dysfonctions érectiles et des problèmes de fertilité chez les hommes. Mots-clés: Nymphaea lotus, pro-érectile, androgénique, fertilité, diabétiques, rat male

The contexts of scratching behavior and postconflict behavior in squirrel monkeys (Saimiri sciureus)

Self-directed behavior (SDB), such as scratching, is a reliable indicator of emotional arousal in non-human primates. In contrast, affiliative behavior, such as social grooming, has been shown to have a calming effect in primates and reduce arousal. In order to test whether the expression of SDB was related to arousal, the scratching behavior of eight captive squirrel monkeys (Saimiri sciureus) was compared across four social contexts (huddling, proximity to others, solitary and post-conflict). In addition,rates of scratching were examined before and after affiliative behavior during the postconflict context. I tested for this effect by using the post-conflict/matched control(PC/MC) method in which post-conflict (PC) behavior of an animal is compared to thebehavior of the same animal in a baseline, nonaggressive situation or a matched control(MC). Context and associated scratching data were obtained from a total of 98 hours of focal sample data. Scratching was significantly lower while animals were huddling thanthe other two contexts. Scratching rates while solitary were significantly higher than those occurring while animals were in proximity. Scratching was also higher in PC than MC. Following conflict, animals were significantly more likely to make contact withthird parties not involved in aggression. Most of these (79%) were a third party approaching a combatant. Further, scratching rates decreased following post-conflict third party contacts and the decrease was not due to a general decrease in scratching thatmight have been occurring after the aggressive interaction. Huddling behavior appears to reduce arousal in squirrel monkeys and may act as a tension-reduction mechanism. The elevated scratching in the solitary context may suggest that squirrel monkeys may be engaged in activities while solitary, such as vigilant behavior that may increase arousal. The third party post conflict affiliative contacts observed were the first such interactions observed in squirrel monkeys. The fact that these third contacts reduced scratching ratesin the combatants indicates that 'consolation' may have been demonstrated in this species. The overall pattern of results suggested that scratching was reliable behavioral indicator of anxiety in squirrel monkeys. These results indicate that overt behavior can be used to assess emotional states in this and other species, acting as a mediator to understanding how emotions regulate social behavior.

Pattern of mineralization after regenerative periodontal therapy with enamel matrix proteins

A derivative (EMD) of enamel matrix proteins (EMPs) is used for periodontal regeneration because EMPs are believed to induce the formation of acellular extrinsic fiber cementum (AEFC). Other reports, however, indicate that EMPs have osteogenic potential. The aim of this study was to characterize the nature of the tissue that forms on the root surface following application of EMD. Ten human teeth affected by periodontitis and scheduled for extraction were treated with EMD. Four to six weeks later, they were extracted and processed for analysis by light microscopy and transmission electron microscopy. Immunocytochemistry with antibodies against bone sialoprotein (BSP) and osteopontin (OPN) was performed to determine the mineralization pattern. The newly formed tissues on the root were thick and contained embedded cells. Small mineralization foci were regularly seen, and large organic matrix patches were occasionally seen, but a distinct mineralization front was lacking. While labeling for BSP was always associated with small mineralization foci and large matrix patches, OPN labeling was seen inconsistently. It is concluded that tissues resembling either cellular intrinsic fiber cementum or a type of bone were observed. The mineralization pattern mostly resembled that found in bone, except for a few areas that exhibited a hitherto undescribed mineralization pattern.

Human adrenal corticocarcinoma NCI-H295R cells produce more androgens than NCI-H295A cells and differ in 3beta-hydroxysteroid dehydrogenase type 2 and 17,20 lyase activities

The human adrenal cortex produces mineralocorticoids, glucocorticoids, and androgens in a species-specific, hormonally regulated, zone-specific, and developmentally characteristic fashion. Most molecular studies of adrenal steroidogenesis use human adrenocortical NCI-H295A and NCI-H295R cells as a model because appropriate animal models do not exist. NCI-H295A and NCI-H295R cells originate from the same adrenocortical carcinoma which produced predominantly androgens but also smaller amounts of mineralocorticoids and glucocorticoids. Research data obtained from either NCI-H295A or NCI-H295R cells are generally compared, although for the same experiments no direct comparison between the two cell lines has been performed. Therefore, we compared the steroid profile and the expression pattern of important genes involved in steroidogenesis in both cell lines. We found that steroidogenesis differs profoundly. NCI-H295A cells produce more mineralocorticoids, whereas NCI-H295R cells produce more androgens. Expression of the 3beta-hydroxysteroid dehydrogenase (HSD3B2), cytochrome b5, and sulfonyltransferase genes is higher in NCI-H295A cells, whereas expression of the cytochrome P450c17 (CYP17), 21-hydroxylase (CYP21), and P450 oxidoreductase genes does not differ between the cell lines. We found lower 3beta-hydroxysteroid dehydrogenase type 2 but higher 17,20-lyase activity in NCI-H295R cells explaining the 'androgenic' steroid profile for these cells and resembling the zona reticularis of the human adrenal cortex. Both cell lines were found to express the ACTH receptor at low levels consistent with low stimulation by ACTH. By contrast, both cell lines were readily stimulated by 8Br-cAMP. The angiotensin type 1 receptor was highly expressed in NCI-H295R than NCI-H295A cells and angiotensin II stimulated steroidogenesis in NCI-H295R but not NCI-H295A cells. Our data suggest that comparative studies between NCI-H295A and NCI-H295R cells may help find important regulators of mineralocorticoid or androgen biosynthesis.

EFFECT OF ELECTRICAL DISCHARGE PATTERN ON SPARK IGNITED FLAME KERNEL DEVELOPMENT

Fuel-lean combustion and exhaust gas recirculation (EGR) in spark ignition engines improve engine efficiency and reduce emission. However, flame initiation becomes more difficult in lean and dilute fuel-air mixture with traditional spark discharge. This research proposal will first provide an intensive review on topics related to spark ignition including properties of electrical discharge, flame kernel behavior and spark ignition modeling and simulation. Focus will be laid on electrical discharge pattern effect as it is showing prospect in extending ignition limits in SI engines. An experimental setup has been built with an optically accessible constant volume combustion vessel. Multiple imaging techniques as well as spectroscopy will be applied. By varying spark discharge patterns, preliminary test results are available on consequent flame kernel development. In addition to experimental investigation of spark plasma and flame kernel development, spark ignition modeling with detailed description of plasma channel is also proposed for this study.

Hypervigilance-avoidance pattern in spider phobia

Cognitive-motivational theories of phobias propose that patients' behavior is characterized by a hypervigilance-avoidance pattern. This implies that phobics initially direct their attention towards fear-relevant stimuli, followed by avoidance that is thought to prevent objective evaluation and habituation. However, previous experiments with highly anxious individuals confirmed initial hypervigilance and yet failed to show subsequent avoidance. In the present study, we administered a visual task in spider phobics and controls, requiring participants to search for spiders. Analyzing eye movements during visual exploration allowed the examination of spatial as well as temporal aspects of phobic behavior. Confirming the hypervigilance-avoidance hypothesis as a whole, our results showed that, relative to controls, phobics detected spiders faster, fixated closer to spiders during the initial search phase and fixated further from spiders subsequently.

STRUCTURAL CONTROL OF A SMALL-SCALE TEST-BED SHAKER STRUCTURE USING A SPONGE-TYPE MAGNETO-RHEOLOGICAL FLUID DAMPER

Semi-active damping devices have been shown to be effective in mitigating unwanted vibrations in civil structures. These devices impart force indirectly through real-time alterations to structural properties. Simulating the complex behavior of these devices for laboratory-scale experiments is a major challenge. Commercial devices for seismic applications typically operate in the 2-10 kN range; this force is too high for small-scale testing applications where requirements typically range from 0-10 N. Several challenges must be overcome to produce damping forces at this level. In this study, a small-scale magneto-rheological (MR) damper utilizing a fluid absorbent metal foam matrix is developed and tested to accomplish this goal. This matrix allows magneto-rheological (MR) fluid to be extracted upon magnetic excitation in order to produce MR-fluid shear stresses and viscosity effects between an electromagnetic piston, the foam, and the damper housing. Dampers for uniaxial seismic excitation are traditionally positioned in the horizontal orientation allowing MR-fluid to gather in the lower part of the damper housing when partially filled. Thus, the absorbent matrix is placed in the bottom of the housing relieving the need to fill the entire device with MR-fluid, a practice that requires seals that add significant unwanted friction to the desired low-force device. The damper, once constructed, can be used in feedback control applications to reduce seismic vibrations and to test structural control algorithms and wireless command devices. To validate this device, a parametric study was performed utilizing force and acceleration measurements to characterize damper performance and controllability for this actuator. A discussion of the results is presented to demonstrate the attainment of the damper design objectives.

[Diabetes update: preventing type 2 diabetes. Individualized stepwise therapy (oral antidiabetic agents). Multifactorial intervention]

Preclinical disorders of glucose metabolism should be systematically included in the high-risk group for diabetes mellitus and affected individuals provided with preventive measures. Their underlying insulin resistance is determined with the help of a checklist and a method called homeostasis model assessment (HOMA). Patients with impaired fasting glucose (IFG) must change their lifestyles. If this does not lead to a response or the patient is unable to modify behavior, medication is required. In the case of manifest type 2 diabetes mellitus, a graded schedule is used for differential management, which should be based on nutritional and exercise therapy. Oral medication with metformin is probably the drug of choice in both obese and non-obese patients. It is crucial not to delay raising the level of treatment until HbA1c has fallen to within an unsatisfactory range (wait-and-see strategy). Rather, the level should be intensified when persistent exacerbation starts to become apparent (proactive therapy). In diabetes mellitus, the same guidelines for secondary prevention apply to the associated cardiovascular risk factors as with coronary heart disease. An intensified and, especially, early treatment is to be preferred over a conservative, wait-and-see approach, in this case as well.

Swimming and diving behavior in apes (Pan troglodytes and Pongo pygmaeus): first documented report

Extant hominoids, including humans, are well known for their inability to swim instinctively. We report swimming and diving in two captive apes using visual observation and video recording. One common chimpanzee and one orangutan swam repeatedly at the water surface over a distance of 2-6 m; both individuals submerged repeatedly. We show that apes are able to overcome their negative buoyancy by deliberate swimming, using movements which deviate from the doggy-paddle pattern observed in other primates. We suggest that apes' poor swimming ability is due to behavioral, anatomical, and neuromotor changes related to an adaptation to arboreal life in their early phylogeny. This strong adaptive focus on arboreal life led to decreased opportunities to interact with water bodies and consequently to a reduction of selective pressure to maintain innate swimming behavior. As the doggy paddle is associated with quadrupedal walking, a deviation from terrestrial locomotion might have interfered with the fixed rhythmic action patterns responsible for innate swimming.

Canine keratinocytes upregulate type I interferons and proinflammatory cytokines in response to poly(dA:dT) but not to canine papillomavirus.

Papillomaviruses (PV) are double stranded (ds) DNA viruses that infect epithelial cells within the skin or mucosa, most often causing benign neoplasms that spontaneously regress. The immune system plays a key role in the defense against PVs. Since these viruses infect keratinocytes, we wanted to investigate the role of the keratinocyte in initiating an immune response to canine papillomavirus-2 (CPV-2) in the dog. Keratinocytes express a variety of pattern recognition receptors (PRR) to distinguish different cutaneous pathogens and initiate an immune response. We examined the mRNA expression patterns for several recently described cytosolic nucleic acid sensing PRRs in canine monolayer keratinocyte cultures using quantitative reverse transcription-polymerase chain reaction. Unstimulated normal cells were found to express mRNA for melanoma differentiation associated gene 5 (MDA5), retinoic acid-inducible gene I (RIG-I), DNA-dependent activation of interferon regulatory factors, leucine rich repeat flightless interacting protein 1, and interferon inducible gene 16 (IFI16), as well as their adaptor molecules myeloid differentiation primary response gene 88, interferon-β promoter stimulator 1, and endoplasmic reticulum-resident transmembrane protein stimulator of interferon genes. When stimulated with synthetic dsDNA [poly(dA:dT)] or dsRNA [poly(I:C)], keratinocytes responded with increased mRNA expression levels for interleukin-6, tumor necrosis factor-α, interferon-β, RIG-I, IFI16, and MDA5. There was no detectable increase in mRNA expression, however, in keratinocytes infected with CPV-2. Furthermore, CPV-2-infected keratinocytes stimulated with poly(dA:dT) and poly(I:C) showed similar mRNA expression levels for these gene products when compared with expression levels in uninfected cells. These results suggest that although canine keratinocytes contain functional PRRs that can recognize and respond to dsDNA and dsRNA ligands, they do not appear to recognize or initiate a similar response to CPV-2.

An examination of the Gonorrhea Cases & Places Study: An analysis of the Theory of Gender and Power, Situational/Environmental Variables Theory, and Sexual Script Theory as it relates to risky sexual behavior in African American adults

Objective. The purpose of the study is to provide a holistic depiction of behavioral & environmental factors contributing to risky sexual behaviors among predominantly high school educated, low-income African Americans residing in urban areas of Houston, TX utilizing the Theory of Gender and Power, Situational/Environmental Variables Theory, and Sexual Script Theory. Methods. A cross-sectional study was conducted via questionnaires among 215 Houston area residents, 149 were women and 66 were male. Measures used to assess behaviors of the population included a history of homelessness, use of crack/cocaine among several other illicit drugs, the type of sexual partner, age of participant, age of most recent sex partner, whether or not participants sought health care in the last 12 months, knowledge of partner's other sexual activities, symptoms of depression, and places where partner's were met. In an effort to determine risk of sexual encounters, a risk index employing the variables used to assess condom use was created categorizing sexual encounters as unsafe or safe. Results. Variables meeting the significance level of p<.15 for the bivariate analysis of each theory were entered into a binary logistic regression analysis. The block for each theory was significant, suggesting that the grouping assignments of each variable by theory were significantly associated with unsafe sexual behaviors. Within the regression analysis, variables such as sex for drugs/money, low income, and crack use demonstrated an effect size of ≥ ± 1, indicating that these variables had a significant effect on unsafe sexual behavioral practices. Conclusions. Variables assessing behavior and environment demonstrated a significant effect when categorized by relation to designated theories.

Northern hemispheric winter warming pattern after tropical volcanic eruptions: Sensitivity to the ozone climatology

An important key for the understanding of the dynamic response to large tropical volcanic eruptions is the warming of the tropical lower stratosphere and the concomitant intensification of the polar vortices. Although this mechanism is reproduced by most general circulation models today, most models still fail in producing an appropriate winter warming pattern in the Northern Hemisphere. In this study ensemble sensitivity experiments were carried out with a coupled atmosphere-ocean model to assess the influence of different ozone climatologies on the atmospheric dynamics and in particular on the northern hemispheric winter warming. The ensemble experiments were perturbed by a single Tambora-like eruption. Larger meridional gradients in the lower stratospheric ozone favor the coupling of zonal wind anomalies between the stratosphere and the troposphere after the eruption. The associated sea level pressure, temperature, and precipitation patterns are more pronounced and the northern hemispheric winter warming is highly significant. Conversely, weaker meridional ozone gradients lead to a weaker response of the winter warming and the associated patterns. The differences in the number of stratosphere-troposphere coupling events between the ensembles experiments indicate a nonlinear response behavior of the dynamics with respect to the ozone and the volcanic forcing.

In vitro analog of classical conditioning of feeding behavior in aplysia.

The feeding behavior of Aplysia californica can be classically conditioned using tactile stimulation of the lips as a conditioned stimulus (CS) and food as an unconditioned stimulus (US). Moreover, several neural correlates of classical conditioning have been identified. The present study extended previous work by developing an in vitro analog of classical conditioning and by investigating pairing-specific changes in neuronal and synaptic properties. The preparation consisted of the isolated cerebral and buccal ganglia. Electrical stimulation of a lip nerve (AT4) and a branch of the esophageal nerve (En2) served as the CS and US, respectively. Three protocols were used: paired, unpaired, and US alone. Only the paired protocol produced a significant increase in CS-evoked fictive feeding. At the cellular level, classical conditioning enhanced the magnitude of the CS-evoked synaptic input to pattern-initiating neuron B31/32. In addition, paired training enhanced both the magnitude of the CS-evoked synaptic input and the CS-evoked spike activity in command-like neuron CBI-2. The in vitro analog of classical conditioning reproduced all of the cellular changes that previously were identified following behavioral conditioning and has led to the identification of several new learning-related neural changes. In addition, the pairing-specific enhancement of the CS response in CBI-2 indicates that some aspects of associative plasticity may occur at the level of the cerebral sensory neurons.

Hepatic and renal cytochrome p450 gene regulation during citrobacter rodentium infection in wild-type and toll-like receptor 4 mutant mice.

Citrobacter rodentium is the rodent equivalent of human enteropathogenic Escherichia coli infection. This study investigated regulation of hepatic and renal cytochrome P450 (P450) mRNAs, hepatic P450 proteins, cytokines, and acute phase proteins during C. rodentium infection. Female C3H/HeOuJ (HeOu) and C3H/HeJ (HeJ) mice [which lack functional toll-like receptor 4 (TLR4)] were infected with C. rodentium by oral gavage and sacrificed 6 days later. Hepatic CYP4A10 and 4A14 mRNAs were decreased in HeOu mice (<4% of control). CYP3A11, 2C29, 4F14, and 4F15 mRNAs were reduced to 16 to 55% of control levels, whereas CYP2A5, 4F16, and 4F18 mRNAs were induced (180, 190, and 600% of control, respectively). The pattern of P450 regulation in HeJ mice was similar to that in HeOu mice for most P450s, with the exception of the TLR4 dependence of CYP4F15. Hepatic CYP2C, 3A, and 4A proteins in both groups were decreased, whereas CYP2E protein was not. Renal CYP4A10 and 4A14 mRNAs were significantly down-regulated in HeOu mice, whereas other P450s were unaffected. Most renal P450 mRNAs in infected HeJ mice were increased, notably CYP4A10, 4A14, 4F18, 2A5, and 3A13. Hepatic levels of interleukin (IL)-1beta, IL-6, and tumor necrosis factor alpha (TNFalpha) mRNAs were significantly increased in infected HeOu mice, whereas only TNFalpha mRNA was significantly increased in HeJ mice. Hepatic alpha1-acid glycoprotein was induced in both groups, whereas alpha-fibrinogen and angiotensinogen were unchanged. These data indicate that hepatic inflammation induced by C. rodentium infection is mainly TLR4-independent and suggest that hepatic P450 down-regulation in this model may be cytokine-mediated.