Penile erection and cardiovascular function: effects and pathophysiology

Penile erection (PE) is a hemodynamic event that results from a neuroendocrine process, and it is influenced by the cardiovascular status of the patient. However, it may also modulate an individual's cardiovascular events. The present study provides the mechanisms involved in the association of PE and cardiovascular function. Erection upsurges the cardiac rate, blood pressure, and oxygen uptake. Sex-enhancing strategies, such as phosphodiesterase inhibitors, alprostadil, and testosterone also promote vasodilatation and cardiac performance, thus preventing myocardial infarction. More so, drugs that are used in the treatment of hypertensive heart diseases (such as angiotensin system inhibitors and β-blockers) facilitate vasodilatation and PE. These associations have been linked with nitric oxide- and testosterone-dependent enhancing effects on the vascular endothelium. In addition, impaired cardiovascular function may negatively impact PE; therefore, impaired PE may be a pointer to cardiovascular pathology. Hence, evaluation of the cardiovascular status of an individual with erectile dysfunction (ED) is essential. Also, employing strategies that are used in maintaining optimal cardiac function may be useful in the management of ED.

Febuxostat attenuates aluminum chloride-induced hepatorenal injury in rats with the impact of Nrf2, Crat, Car3, and MNK-mediated apoptosis

Aluminum (Al) is a ubiquitous xenobiotic with known toxicity for both humans and animals. Our study was conducted to investigate the protective role of febuxostat (Feb) against aluminum chloride (AlCl3)-induced hepatorenal injury in rats. Hepatorenal injury was induced by oral administration of AlCl3 (40 mg/kg b.w.), for 2 months. Twenty-four male Sprague-Dawley rats were randomly allocated into four groups (six rats/group). The first group received the vehicle thought the experiment. The second group was considered as a control positive group. The third and fourth groups received oral treatment of Feb (10 mg/kg.b.w.) and (15 mg/kg.b.w.), respectively with AlCl3, concurrently for 2 months. Twenty-four hours, after the last treatment, serum biochemical, molecular, histopathology, and immunohistochemical studies were evaluated. Our findings showed that rats intoxicated with Alcl₃ had disturbed biochemical picture. In addition, intoxication with AlCl3 increased oxidative stress and apoptosis, as demonstrated by an increase in malodialdeyde (MDA), carnitine o-acetyltransferase (Crat), and carbonic anhydrase (Car3) with a decrease in glutathione (GSH), MAP kinase-interacting serine/threonine kinase (MNK) and nuclear factor-erythroid 2-related factor 2 (Nrf2) mRNA expression. Furthermore, the levels of tumor necrosis factor-alpha (TNF-α) and the levels of caspase-3 were elevated with sever hepatic and renal pathological changes. Conversely, Feb (15 mg/kg.b.w.) could improve the serum biochemical indices and repressed MDA, Crat, and Car3 levels, whereas it increased GSH, MNK, and Nrf2 levels. Feb inhibited the apoptotic effect of AlCl3 in the liver and kidney by decreasing caspase-3 and TNF-α expression. The protective effect of Feb against AlCl3 toxicity was confirmed by histopathological findings. Moreover, molecular docking studies supported the anti-inflammatory effect of Feb due to its significant binding interactions with cyclooxygenase-1 (COX-1), NF-kappa-B-inducing kinase (NIK), and mitogen-activated protein kinases-p38 (MAPK-p38). The findings suggest that Feb system Feb can avert Alcl3-induced hepatotoxicity and nephrotoxicity by enhancing the antioxidant defense system, and inhibiting the inflammatory cascade and apoptosis.

Radiotherapy of the Hepatocellular Carcinoma in Mice Has a Time-Of-Day-Dependent Impact on the Mouse Hippocampus

Chronic liver diseases including hepatocellular carcinoma (HCC) create a state of chronic inflammation that affects the brain via the liver-brain axis leading to an alteration of neurotransmission and cognition. However, little is known about the effects of HCC on the hippocampus, the key brain region for learning and memory. Moreover, radiotherapy used to treat HCC has severe side effects that impair patients' life quality. Thus, designing optimal strategies, such as chronotherapy, to enhance the efficacy and reduce the side effects of HCC treatment is critically important. We addressed the effects of HCC and the timed administration of radiotherapy in mice on the expression of pro-inflammatory cytokines, clock genes, markers for glial activation, oxidative stress, neuronal activity and proliferation in the hippocampal neurogenic niche. Our data showed that HCC induced the upregulation of genes encoding for pro-inflammatory cytokines, altered clock gene expressions and reduced proliferation in the hippocampus. Radiotherapy, in particular when applied during the light/inactive phase enhanced all these effects in addition to glial activation, increased oxidative stress, decreased neuronal activity and increased levels of phospho(p)-ERK. Our results suggested an interaction of the circadian molecular clockwork and the brain's innate immune system as key players in liver-brain crosstalk in HCC and that radiotherapy when applied during the light/inactive phase induced the most profound alterations in the hippocampus.

Biocompatibility and Surface Roughness of Different Sustainable Dental Composite Blocks: Comprehensive In Vitro Study

The study purposed to investigate the biocompatibility and sustainability of two computer-aided design/computer-aided manufacturing (CAD/CAM) resin-based composites compared to a resin-modified ceramic in terms of surface roughness, biofilm formation, cytotoxicity, genotoxicity, and cellular changes observed under transmission electron microscopy (TEM). Three CAD/CAM blocks were used, two resin-based composites [Brilliant Crios (BC) and Cerasmart, (CS) and one hybrid ceramic (Vita Enamic (EN)]. Each block was sectioned into 10 × 12 × 2 mm specimens, followed by finishing and polishing. Each specimen was evaluated for surface roughness using 3D optical profilometry and scanned by scanning electron microscopy. Biofilm formation and its relation to surface roughness have been investigated for all tested materials. A Hep-2 cell line was used to investigate the viability through MTT assay. The cytotoxicity of the materials was measured at 24, 48, and 168 h. The activity of P53, caspase 3, and cytochrome C was evaluated to detect the genotoxicity of different groups, followed by TEM tracking of the cellular changes. Statistical analysis was implemented by utilizing a one-way analysis of variance test. The significance was set at P ≤ 0.05. With regard to the surface roughness, no statistically significant differences were shown between groups. BC possessed the highest biofilm formation value, followed by EN and CS, with no significance between them. No correlation between surface roughness of tested materials and biofilm formation was shown. Considering viability, the highest values were recorded for EN, whereas BC showed the lowest values. P53-fold changes in EN were significantly the lowest, indicating less genotoxicity. Within the current study's limitations, BC showed the highest biofilm formation. However, no significant surface roughness difference or correlation with biofilm formation was observed in tested materials. EN showed the lowest cytotoxicity and the highest viability. EN revealed the best compatibility performance among tested materials. On the contrary, the BC exhibited fewer preferences.

Resveratrol: A Potential Protector Against Benzo[a]pyrene- Induced Lung Toxicity

<b>Background and Objective:</b> Benzo[a]pyrene (B[a]P), a major component of lipophilic pollutants then can be translated to diffluent substances. The aim of t he present article was to investigate protective activity of resveratrol against lung toxicity induced by B[a]P. Material and Methods: Male Sprague-Dawley rats were randomly assigned to 6 groups (6 animals/group): 3 negative control groups, control positive, B[a]P (20 mg kg<sup></sup><sup>1</sup> b.wt., resveratrol (50 mg kg<sup></sup><sup>1</sup> b.wt.)-B[a]P and vitamin C (1 g kg<sup></sup><sup>1</sup> b.wt.)-B[a]P groups. <b>Results:</b> The daily oral administration of the resveratrol (50 mg kg<sup></sup><sup>1</sup> b.wt.) and vitamin C (1 g kg<sup></sup><sup>1</sup> b.wt.) for 30 days to rats treated with B[a]P (20 mg kg<sup></sup><sup>1</sup> b.wt.) resulted in a significant improve plasma cholesterol, triglyceride and HDL-C as well as serum TNF-α, TBARS, IL-2,IL-6, haptoglobin, histamine, IgA, Ig E,Ig G and Ig M in B[a]P treated rats. On the other hand oral administration of resveratrol elevated the SOD, GPx and GR gene expression in lung rats treated with B[a]P. Furthermore, resveratrol and vitamin C nearly normalized these effects in lung histoarchitecture. <b>Conclusion:</b> The obtained biochemical, molecular biology and histological results of this study proved the lung protective activity of resveratrol against B[a]P induced lung toxicity in rats.

Downregulation of TLR4-NF-?B-p38 MAPK Signalling in Cholestatic Rats Treated with Cranberry Extract

<b>Background and Objective:</b> Cholestasis is a liver disease that occurs when bile flow is restricted or blocked. Estrogen-induced cholestasis is marked by a reduction in bile flow and the accumulation of bile acids in the liver as well as liver damage. The aim was to evaluate the hepatoprotective effect on EE-induced cholestasis in rats of Cranberry Water Extract (CWE). <b>Materials and Methods:</b> Adult albino rats weighing approximately 150±10 g were divided into six groups of six animals each. As control groups, three groups (I, II and IV) and three experimental groups were used (III, V, VI). <b>Results:</b> Oral administration for 15 days of CWE (150 mg kg<sup>1</sup> b.wt.) in EE-treated rats (100 μg kg<sup>1</sup> 5 days b.wt.) improved serum cholesterol, bile acid and TBIL as well as hepatic SOD and GPx significantly. Also, CWE inhibited ALP, ALT, γ-GT activity as well as levels of TNF-α, NO, MMP-2 and MMP-9 and MDA in comparison with the EE treatment rats. On the other hand, the liver TLR4, NF-κB and p38MAPK gene expression was down regulated group of rats administrated with cranberry extract when compared with the EE-treated rats. CWE's prophylactic action II is more pronounced than prophylactic one. The hepatoprotective effects of cranberry in restoring normal liver functional ability were also supported by histopathological examination of liver tissues. <b>Conclusion:</b> The results show clearly that cranberry extract has a strong prophylactic effect in EE-induced cholestasis by normalizing the levels of TLR4, NF-κB and p38MAPK gene expression.

Does timing matter in radiotherapy of hepatocellular carcinoma? An experimental study in mice

This study investigates whether a chronotherapeutic treatment of hepatocellular carcinoma (HCC) may improve treatment efficacy and mitigate side effects on non-tumoral liver (NTL). HCC was induced in Per2::luc mice which were irradiated at four time points of the day. Proliferation and DNA-double strand breaks were analyzed in irradiated and nonirradiated animals by detection of Ki67 and γ-H2AX. Prior to whole animal experiments, organotypic slice cultures were investigated to determine the dosage to be used in whole animal experiments. Irradiation was most effective at the proliferation peaks in HCC at ZT02 (early inactivity phase) and ZT20 (late activity phase). Irradiation effects on NTL were minimal at ZT20. As compared with NTL, nonirradiated HCC revealed disruption in daily variation and downregulation of all investigated clock genes except Per1. Irradiation affected rhythmic clock gene expression in NTL and HCC at all ZTs except at ZT20 (late activity phase). Irradiation at ZT20 had no effect on total leukocyte numbers. Our results indicate ZT20 as the optimal time point for irradiation of HCC in mice at which the ratio between efficacy of tumor treatment and toxic side effects was maximal. Translational studies are now needed to evaluate whether the late activity phase is the optimal time point for irradiation of HCC in man.

Antioxidant and Antiapoptotic Effects of a Turraea fischeri Leaf Extract on Cryopreserved Goat Sperm

This study evaluated the efficacy of Turraea fischeri leaf extract for maintaining the viability of cryopreserved goat sperm. Ejaculated semen was collected from 5 mature Baladi bucks (50-60 kg, 2-4 years of age) and those samples with mass motility ≥ 70% and sperm concentration ≥ 2.5 × 109/mL were selected, pooled, and divided into 4 aliquots. Each aliquot was diluted in Tris-citric-soybean lecithin extender containing a different concentration of T. fischeri leaf extract (0, 125, 250, or 375 µg/mL). Treated semen samples were cooled to 5 °C, transferred to 0.25-mL French straws, and stored in liquid nitrogen (LN2) at -196 °C. After thawing, membrane integrity was examined by transmission electron microscopy, apoptotic activity by Annexin/propidium iodide staining and flow cytometry, and both enzyme activities and antioxidant capacity by spectroscopic assays. The leaf extract at 375 µg/mL significantly improved semen quality as indicated by enhanced total antioxidant capacity, reduced H2O2 concentration, a greater proportion of structurally intact motile sperm, and concomitant reductions in apoptosis and necrosis. The extract also significantly increased the proportion of sperm with a contiguous plasma membrane and intact acrosome (p < 0.05). Furthermore, LC-MS revealed numerous secondary metabolites in the extract that may contribute to sperm cryopreservation.

P2Y2 deficiency impacts adult neurogenesis and related forebrain functions

Adult neurogenesis occurs particularly in the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ) of the lateral ventricle. This continuous addition of neurons to pre-existing neuronal networks is essential for intact cognitive and olfactory functions, respectively. Purinergic signaling modulates adult neurogenesis, however, the role of individual purinergic receptor subtypes in this dynamic process and related cognitive performance is poorly understood. In this study, we analyzed the role of P2Y₂ receptor in the neurogenic niches and in related forebrain functions such as spatial working memory and olfaction using mice with a targeted deletion of the P2Y₂ receptor (P2Y2^-/- ). Proliferation, migration, differentiation, and survival of neuronal precursor cells (NPCs) were analyzed by BrdU assay and immunohistochemistry; signal transduction pathway components were analyzed by immunoblot. In P2Y2^-/- mice, proliferation of NPCs in the SGZ and the SVZ was reduced. However, migration, neuronal fate decision, and survival were not affected. Moreover, p-Akt expression was decreased in P2Y2^-/- mice. P2Y2^-/- mice showed an impaired performance in the Y-maze and a higher latency in the hidden food test. These data indicate that the P2Y₂ receptor plays an important role in NPC proliferation as well as in hippocampus-dependent working memory and olfactory function.

Bending effect on the Majorana bound states in planar Josephson junctions

We consider the bending effect on the formation of Majorana bound states (MBSs) in planar Josephson junctions where the normal stripe is tilted in a V shape. Our results show that the MBSs remain robust for moderate bending angles. Beyond some critical angles, the degradation of MBSs can be revealed by its eigenspectrum as well as the Majorana polarization (MP). Our results show that the parameter space of bending angle for robust MBSs can be significantly enlarged by tuning the superconducting phase difference across the Josephson junction. These findings suggest that the interplay of the junction geometry and the device parameters provides richer degree of freedom in designing topological superconducting devices for future applications. The MP analysis is an indispensable tool for characterizing the Majorana states.

Relationship between locomotor activity rhythm and corticosterone levels during HCC development, progression, and treatment in a mouse model

Cancer-related fatigue (CRF) and stress are common symptoms in cancer patients and represent early side effects of cancer treatment which affect the life quality of the patients. CRF may partly depend on disruption of the circadian rhythm. Locomotor activity and corticosterone rhythms are two important circadian outputs which can be used to analyze possible effects on the circadian function during cancer development and treatment. The present study analyzes the relationship between locomotor activity rhythm, corticosterone levels, hepatocellular carcinoma (HCC) development, and radiotherapy treatment in a mouse model. HCC was induced in mice by single injection of diethylnitrosamine (DEN) and chronic treatment of phenobarbital in drinking water. Another group received chronic phenobarbital treatment only. Tumor bearing animals were divided randomly into four groups irradiated at four different Zeitgeber time points. Spontaneous locomotor activity was recorded continuously; serum corticosterone levels and p-ERK immunoreaction in the suprachiasmatic nucleus (SCN) were investigated. Phenobarbital treated mice showed damped corticosterone levels and a less stable 24 hours activity rhythm as well as an increase in activity during the light phase, reminiscent of sleep disruption. The tumor mice showed an increase in corticosterone level during the inactive phase and decreased activity during the dark phase, reminiscent of CRF. After irradiation, corticosterone levels were further increased and locomotor activity rhythms were disrupted. Lowest corticosterone levels were observed after irradiation during the early light phase; thus, this time might be the best to apply radiotherapy in order to minimize side effects.

Theoretical investigation of the scanning tunneling microscopy of Majorana bound states in topological superconductor vortices

Scanning tunneling microscopy (STM) is an indispensable tool in detecting Majorana bound states (MBSs) in vortices of topological superconductors. By reducing the computational complexity via non-uniform grids, we systematically study the tunnel coupling as well as the temperature dependence of the differential conductance of MBSs in two dimensional devices. Numerical results show that the conductance peak approaches the quantized value 2e ²/h in strong coupling limit at low temperatures which are characteristic features of MBSs. More interestingly, a conductance local minimum in the spatially scanning is observed when the STM tip is placed at the vortex center. The dip structure can be enhanced with increased temperature or enlarged vortex size. We ascribe this observation to the sensitivity of the Andreev reflection processes of carriers at the vortex center where the thermal energy could be comparable to the vanishing pair potential. We also investigate the STM of two-vortex systems where the hybridization of the vortices can lead to oscillatory behavior of the state energy. With small inter-vortex distances, the original MBSs in vortices can merge into topologically trivial states and the conductance peak can be significantly suppressed.

A Polyphenol-Rich Extract From Entada abyssinica Reduces Oxidative Damage in Cryopreserved Ram Semen

The Splinter bean, Entada abyssinica, is widely used in folk medicine. In the current work, we profiled the secondary metabolites from E. abyssinica bark extract using LC-MS and investigated its effect on cryopreserved ram semen. Twenty-eight compounds, including tannins and gallic acid derivatives that prevailed in the extract, were tentatively identified. Results showed that the quality of the post-thawed semen showed a significant improvement when the extract was added to the extender at a concentration of 375 μg/mL. The progressive motility and plasma membrane integrity of sperm cells were significantly increased in the post-thawed semen; however, the total antioxidant capacity (TAC) was insignificantly increased. A significant decrease in the concentration of hydrogen peroxide was detected as well. No significant changes were observed in activities of lactate dehydrogenase (LDH), alanine aminotransaminase (ALT), and aspartate transaminase (AST) within the treated samples. Intact sperm percentage was significantly increased, while apoptotic and necrotic sperm percentages were reduced significantly. Molecular docking of some individual components from the extract revealed their potential to interfere with the apoptosis cascade in which Bcl-2 is involved. In conclusion, Entada abyssinica appears to be useful for cryopreservation presumably owing to its polyphenol content that has potent antioxidant capacity scavenging reactive oxygen species (ROS), enhancing the endogenous antioxidant system and inhibiting lipid peroxidation.

Time-dependent changes in proliferation, DNA damage and clock gene expression in hepatocellular carcinoma and healthy liver of a transgenic mouse model

Hepatocellular carcinoma (HCC) is highly resistant to anticancer therapy and novel therapeutic strategies are needed. Chronotherapy may become a promising approach because it may improve the efficacy of antimitotic radiation and chemotherapy by considering timing of treatment. To date little is known about time-of-day dependent changes of proliferation and DNA damage in HCC. Using transgenic c-myc/transforming growth factor (TGFα) mice as HCC animal model, we immunohistochemically demonstrated Ki67 as marker for proliferation and γ-H2AX as marker for DNA damage in HCC and surrounding healthy liver (HL). Core clock genes (Per1, Per2, Cry1, Cry2, Bmal 1, Rev-erbα and Clock) were examined by qPCR. Data were obtained from samples collected ex vivo at four different time points and from organotypic slice cultures (OSC). Significant differences were found between HCC and HL. In HCC, the number of Ki67 immunoreactive cells showed two peaks (ex vivo: ZT06 middle of day and ZT18 middle of night; OSC: CT04 and CT16). In ex vivo samples, the number of γ-H2AX positive cells in HCC peaked at ZT18 (middle of the night), while in OSC their number remained high during subjective day and night. In both HCC and HL, clock gene expression showed a time-of-day dependent expression ex vivo but no changes in OSC. The expression of Per2 and Cry1 was significantly lower in HCC than in HL. Our data support the concept of chronotherapy of HCC. OSC may become useful to test novel cancer therapies.

Impact of Targeted Deletion of the Circadian Clock Gene Bmal1 in Excitatory Forebrain Neurons on Adult Neurogenesis and Olfactory Function

The circadian system is an endogenous timekeeping system that synchronizes physiology and behavior with the 24 h solar day. Mice with total deletion of the core circadian clock gene Bmal1 show circadian arrhythmicity, cognitive deficits, and accelerated age-dependent decline in adult neurogenesis as a consequence of increased oxidative stress. However, it is not yet known if the impaired adult neurogenesis is due to circadian disruption or to loss of the Bmal1 gene function. Therefore, we investigated oxidative stress and adult neurogenesis of the two principle neurogenic niches, the hippocampal subgranular zone and the subventricular zone in mice with a forebrain specific deletion of Bmal1 (Bmal1 fKO), which show regular circadian rhythmicity. Moreover, we analyzed the morphology of the olfactory bulb, as well as olfactory function in Bmal1 fKO mice. In Bmal1 fKO mice, oxidative stress was increased in subregions of the hippocampus and the olfactory bulb but not in the neurogenic niches. Consistently, adult neurogenesis was not affected in Bmal1 fKO mice. Although Reelin expression in the olfactory bulb was higher in Bmal1 fKO mice as compared to wildtype mice (Bmal1 WT), the olfactory function was not affected. Taken together, the targeted deletion of Bmal1 in mouse forebrain neurons is associated with a regional increase in oxidative stress and increased Reelin expression in the olfactory bulb but does not affect adult neurogenesis or olfactory function.

Polyphenolics from Albizia harveyi Exhibit Antioxidant Activities and Counteract Oxidative Damage and Ultra-Structural Changes of Cryopreserved Bull Semen

Albizia harveyi is a tropical deciduous tree, found across South and Eastern Africa and widely used in traditional medicine. The leaf extract ameliorated the damaging effects of the frozen-thawing process in cryopreserved bull semen. In a dose-dependent pattern, sperm motility, viability, and membrane integrity were improved compared to the untreated control. Furthermore, the extract increased the percentage of viable sperm cells and reduced the percentages of early apoptotic and apoptotic sperm cells as well as the damage in sperm ultra-structure. These activities are in agreement with the robust antioxidant properties in vitro and in the seminal fluid as observed in the total antioxidant capacity and the lipid peroxidation parameter malondialdehyde. LC-MS yielded 35 compounds. The extract was dominated by quercetin-O-galloyl-hexoside and quercetin-O-pentoside, along with other flavonoid glycosides. The polyphenols are probably responsible for the observed activities. In conclusion, the current findings show that A. harveyi leaves are rich in bioactive polyphenols with functional properties, validating its traditional use.

Terahertz acoustic phonon detection from a compact surface layer of spherical nanoparticles powder mixture of aluminum, alumina and multi-walled carbon nanotube

We present terahertz spectroscopy study on spherical nanoparticles powder mixture of aluminum, alumina, and MWCNTs induced by surface mechanical attrition treatment (SMAT) of aluminum substrates. Surface alloying of AL, Al₂O₃ 0.95% and MWCNTs 0.05% powder mixture was produced during SMAT process, where a compact surface layer of about 200 μm due to ball bombardment was produced from the mixture. Al₂O₃ alumina powder played a significant role in MWCNTs distribution on surface, those were held in deformation surface cites of micro-cavities due to SMAT process of Al. The benefits are the effects on resulted optical properties of the surface studied at the terahertz frequency range due to electrical isolation confinement effects and electronic resonance disturbances exerted on Al electronic resonance at the same range of frequencies. THz acoustic phonon around 0.53-0.6THz (17-20cm^-1) were observed at ambient conditions for the spherical nanoparticles powder mixture of Al, Al₂O₃ and MWCNTs. These results suggested that the presence of Al₂O₃ and MWCNTs during SMAT process leads to the optically detection of such acoustic phonon in the THz frequency range.

Computational study of the inhibitory mechanism of the kinase CDK5 hyperactivity by peptide p5 and derivation of a pharmacophore

The hyperactivity of the cyclic dependent kinase 5 (CDK5) induced by the activator protein p25 has been linked to a number of pathologies of the brain. The CDK5-p25 complex has thus emerged as a major therapeutic target for Alzheimer's disease (AD) and other neurodegenerative conditions. Experiments have shown that the peptide p5 reduces the CDK5-p25 activity without affecting the endogenous CDK5-p35 activity, whereas the peptide TFP5, obtained from p5, elicits similar inhibition, crosses the blood-brain barrier, and exhibits behavioral rescue of AD mice models with no toxic side effects. The molecular basis of the kinase inhibition is not currently known, and is here investigated by computer simulations. It is shown that p5 binds the kinase at the same CDK5/p25 and CDK5/p35 interfaces, and is thus a non-selective competitor of both activators, in agreement with available experimental data in vitro. Binding of p5 is enthalpically driven with an affinity estimated in the low µM range. A quantitative description of the binding site and pharmacophore is presented, and options are discussed to increase the binding affinity and selectivity in the design of drug-like compounds against AD.

Impact of subdomain D1 of the short form S1b of the human prolactin receptor on its inhibitory action on the function of the long form of the receptor induced by prolactin

BACKGROUND

Long-form (LF) homodimers of the human prolactin receptor (PRLR) mediate prolactin's diverse actions. Short form S1b inhibits the LF function through heterodimerization. Reduced S1b/LF-ratio in breast cancer could contribute to tumor development/progression. Current work defines the structural and functional relevance of the D1 domain of S1b on its inhibitory function on prolactin-induced LF function.

METHODS

Studies were conducted using mutagenesis, promoter/signaling analyses, bioluminescence resonance energy transfer (BRET) and molecular modeling approaches.

RESULTS

Mutation of E69 in D1 S1b or adjacent residues at the receptor surface near to the binding pocket (S) causes loss of its inhibitory effect while mutations away from this region (A) or in the D2 domain display inhibitory action as the wild-type. All S1b mutants preserved prolactin-induced Jak2 activation. BRET reveals an increased affinity in D1 mutated S1b (S) homodimers in transfected cells stably expressing LF. In contrast, affinity in S1b homodimers with either D1 (A) or D2 mutations remained unchanged. This favors LF mediated signaling induced by prolactin. Molecular dynamics simulations show that mutations (S) elicit major conformational changes that propagate downward to the D1/D2 interface and change their relative orientation in the dimers.

CONCLUSIONS

These findings demonstrate the essential role of D1 on the S1b structure and its inhibitory action on prolactin-induced LF-mediated function.

GENERAL SIGNIFICANCE

Major changes in receptor conformation and dimerization affinity are triggered by single mutations in critical regions of D1. Our structure-function/simulation studies provide a basis for modeling and design of small molecules to enhance inhibition of LF activation for potential use in breast cancer treatment.

Hospital-acquired Clostridium difficile infection among patients with type 2 diabetes mellitus in acute medical wards

BACKGROUND

Clostridum difficile (C. difficile) infection is increasingly seen among hospitalised patients with type 2 diabetes mellitus but its rate and associated risk factors are not known. We aimed to determine the rate and characteristics of hospital-acquired C. difficile infection in subjects with type 2 diabetes mellitus admitted into acute medical wards.

METHODS

Our prospective cross-sectional study involved 159 patients with established type 2 diabetes mellitus admitted into acute medical wards who developed a hospital-acquired C. difficile infection. Stools were tested for C. difficile toxins using a toxin A/B kit and a toxin A kit. Clinical features, laboratory findings, types of antibiotics, and use of a proton pump inhibitor were examined for their association with the infection.

RESULTS

Thirteen subjects were positive for toxin A and one for toxin B. Using univariable analysis, we found that patients with type 2 diabetes mellitus and hospital acquired C. difficile infection were younger (mean 53.8 years, p=0.02), had diarrhoea and abdominal pain (p=0.001) but no fever. Sepsis (p=0.02) and use of a proton pump inhibitor (p=0.01) were more commonly implicated as the cause of the infection. Of the various types of antibiotics prescribed, carbapenem (28.6% vs 4.1%, p=0.01) and metronidazole (42.9% vs 19.3%, p=0.04) were significantly associated with hospital acquired C. difficile infection.

CONCLUSIONS

Patients with type 2 diabetes mellitus admitted into acute medical wards and who developed hospital-acquired C. difficile infection have distinct characteristics.

Early detection of prostate cancer: evaluating the diagnostic performance of prostate specific antigen by comparing with histological technique among africans

This study was conducted to investigate the diagnostic performance characteristics of prostate specific antigen (PSA) by comparing serum PSA value with histological findings in patients suspevted of having prostate cancer in Aminu Kano Teaching Hospital. Nigeria. Clinical and Laboratory records were examined and collated for serum PSA values, together with histological findings of biopsy specimen, clinical diagnosis, age of patients, and mode of presentation. The serum PSA values were determined by ELECSYS 1010 autoanalysers Roche, Germany based on electrochemiluminescence immunoassay technique. The results show that serum PSA values increase with age in the assymptomatic non-cancer patients who came for medical check up but were within normal limit. In prostatic disease conditions PSA values were raised in benign prostatic hyperplasia 35.957± 4.0315ng/ml, in undifferentiated carcinoma 56.22±4.295ng/ml and adenocarcinoma >100ng/ml as compared to the normal range (0-4ng/ml). These cases were confirmed by histological diagnosis. It is concluded that PSA evaluations is a sensitive marker for prostate cancer but because of various other conditions that affect serum PSA concentration, other methods of investigations such as Digital Rectal examination, Trans Urethral Ultra-Sonography and histological examination should be combined to confirm diagnosis. Prognosis of patients will be better if early diagnosis is made.

Solid-pseudopapillary carcinoma: a case study and literature review

Solid-pseudopapillary tumour (SPT) is a rare exocrine tumour of the pancreas and is considered to have low malignant potential. Few morphological criteria are used to predict malignant behaviour such as equivocal perineural invasion, angioinvasion and invasion to surrounding tissue, and should be designated as solid-pseudopapillary carcinoma (SPC). We report a case of SPC. Clinical and radiological findings are typical for SPT with no metastatic disease. There is no tumour recurrence after 4&emsp14;months postresection. Clinical history and radiological findings were retrieved from the patient's record sheet and Viarad system. H&E staining and few immunoproxidase staining were reviewed by several pathologists. The histological findings are typical for SPT, with additional perineural invasion. There is no angioinvasion or capsular invasion identified. This is our first experience in diagnosing and managing SPC. We look forward to seeing the patient's disease status during her next routine follow-up. We expect good disease-free survival and very low risk of tumour recurrence, in view of only one risk factor (perineural invasion) and uninvolved surgical margins by the tumour.

Microcatheter to recanalization (procedure time) predicts outcomes in endovascular treatment in patients with acute ischemic stroke: when do we stop?

BACKGROUND AND PURPOSE

Endovascular treatment for acute ischemic stroke consists of various mechanical and pharmacologic modalities used for recanalization of arterial occlusions. We performed this study to determine the relationship among procedure time, recanalization, and clinical outcomes in patients with acute ischemic stroke undergoing endovascular treatment.

MATERIALS AND METHODS

We analyzed data from consecutive patients with acute ischemic stroke who underwent endovascular treatment during a 6-year period. Demographic characteristics, NIHSS score before and 24 hours after the procedure, and discharge mRS score were ascertained. Procedure time was defined by the time interval between microcatheter placement and recanalization or completion of the procedure. We estimated the procedure time after which favorable clinical outcome was unlikely, even after adjustment for age, time from symptom onset, and admission NIHSS scores.

RESULTS

We analyzed 209 patients undergoing endovascular treatment (mean age, 65 ± 16 years; 109 [52%] men; mean admission/preprocedural NIHSS score, 15.3 ± 6.8). Complete or partial recanalization was observed in 176 (84.2%) patients, while unfavorable outcome (mRS 3-6) was observed in 138 (66%) patients at discharge. In univariate analysis, patients with procedure time ≤30 minutes had lower rates of unfavorable outcome at discharge compared with patients with procedure time ≥30 minutes (52.3% versus 72.2%, P = .0049). In our analysis, the rates of favorable outcomes in endovascularly treated patients after 60 minutes were lower than rates observed with placebo treatment in the Prourokinase for Acute Ischemic Stroke Trial. In logistic regression analysis, unfavorable outcome was positively associated with age (P = .0012), admission NIHSS strata (P = .0017), and longer procedure times (P = .0379).

CONCLUSIONS

Procedure time in patients with acute ischemic stroke appears to be a critical determinant of outcomes following endovascular treatment. This highlights the need for procedure time guidelines for patients being considered for endovascular treatment in acute ischemic stroke.

Adulticidal Activity of Olea vera, Linum usitatissimum and Piper nigera against Anopheles stephensi and Aedes aegypti under Laboratory Conditions

BACKGROUND

There are several plant extractions which are being used for mosquito control. The aim of this study was to evaluate the efficacy of Olea vera, Linum usitatissimum and Piper nigera against Anopheles stephensi and Aedes aegypti under laboratory conditions.

METHODS

These tests were carried out using WHO recommended bioassay method for adult mosquitoes.

RESULTS

The extracts from black pepper was more effective as adulticide with lowest LC(50) values (2.26% and 8.4%) against Aedes aegypti and Anopheles stephensi after 24 h of exposure while after 48h (1.56% and 5.11%) respectively. In terms of LC(90) value black pepper was best with (8.66% and 30.1%) against Ae. aegypti and An. stephensi after 24 h of exposure while after 48h (4.59% and 17.3%) respectively. In terms of LT(50) black pepper took 15 h to kill 50% tested population of Ae. aegypti while against An. stephensi it took more than 2 days. In terms of percentage mortality black pepper kill 84% of the population of Ae. aegypti and 44.75% of the An. stephensi population.

CONCLUSION

Black pepper showed best results in term of LC(50), LC(90), LT(50) and percentage mortality against Ae. aegypti and An. stephensi. Our study suggested that the plant extracts have potential to kill adult mosquitoes, are environment friendly and can be used for the control of mosquitoes.

The clinical and cost effectiveness of bee honey dressing in the treatment of diabetic foot ulcers

Honey is known, since antiquity, as an effective wound dressing. Emergence of resistant strains and the financial burden of modern dressings, have revived honey as cost-effective dressing particularly in developing countries. Its suitability for all stages of wound healing suggests its clinical effectiveness in diabetic foot wound infections. Thirty infected diabetic foot wounds were randomly selected from patients presenting to Surgery Department, Suez Canal University Hospital, Ismailia, Egypt. Honey dressing was applied to wounds for 3 months till healing, grafting or failure of treatment. Changes in grade and stage of wounds, using University of Texas Diabetic Wound Classification, as well as surface area were recorded weekly. Bacterial load was determined before and after honey dressing. Complete healing was significantly achieved in 43.3% of ulcers. Decrease in size and healthy granulation was significantly observed in another 43.3% of patients. Bacterial load of all ulcers was significantly reduced after the first week of honey dressing. Failure of treatment was observed in 6.7% of ulcers. This study proves that commercial clover honey is a clinical and cost-effective dressing for diabetic wound in developing countries. It is omnipresence and concordance with cultural beliefs makes it a typical environmentally based method for treating these conditions.

Structural and dynamic determinants of ligand binding and regulation of cyclin-dependent kinase 5 by pathological activator p25 and inhibitory peptide CIP

The crystal structure of the cdk5/p25 complex has provided information on possible molecular mechanisms of the ligand binding, specificity, and regulation of the kinase. Comparative molecular dynamics simulations are reported here for physiological conditions. This study provides new insight on the mechanisms that modulate such processes, which may be exploited to control pathological activation by p25. The structural changes observed in the kinase are stabilized by a network of interactions involving highly conserved residues within the cyclin-dependent kinase (cdk) family. Collective motions of the proteins (cdk5, p25, and CIP) and their complexes are identified by principal component analysis, revealing two conformational states of the activation loop upon p25 complexation, which are absent in the uncomplexed kinase and not apparent from the crystal. Simulations of the uncomplexed inhibitor CIP show structural rearrangements and increased flexibility of the interfacial loop containing the critical residue E240, which becomes fully hydrated and available for interactions with one of several positively charged residues in the kinase. These changes provide a rationale for the observed high affinity and enhanced inhibitory action of CIP when compared to either p25 or the physiological activators of cdk5.

The Relative Performance Capabilities of Passive, Active and Semi-Active Car Suspension Systems

Based on the well-known quarter car representation of the automobile suspension design problem, pdomnce parameters relating to passenger discomfort, working space and tyre load variability are generated for passive, active and semi-active suspension systems. Active systems of two types having different hardware implications are considered, and linear optimal control theory is used in each case to derive a good set o control law parameters. The semi-active systems studied have control laws based on the fully active systems, but are capable only of dissipating energy, so that where the corresponding active system would be acting as an energy supply, the semi-active system switches off Practically realizable switching dynamics are assumed in the calculations. Results for all the systems, for one road surface roughness and vehicle speed, are generated in a form which allows comparison between systems of diffient types which have equal suspension working space requirements. The wider implications of the results are discussed, and far-reaching conclusions about the relative capabilities and design features of passive, active and semi-active systems are drawn.

Key issues in the computational simulation of GPCR function: representation of loop domains

Some key concerns raised by molecular modeling and computational simulation of functional mechanisms for membrane proteins are discussed and illustrated for members of the family of G protein coupled receptors (GPCRs). Of particular importance are issues related to the modeling and computational treatment of loop regions. These are demonstrated here with results from different levels of computational simulations applied to the structures of rhodopsin and a model of the 5-HT2A serotonin receptor, 5-HT2AR. First, comparative Molecular Dynamics (MD) simulations are reported for rhodopsin in vacuum and embedded in an explicit representation of the membrane and water environment. It is shown that in spite of a partial accounting of solvent screening effects by neutralization of charged side chains, vacuum MD simulations can lead to severe distortions of the loop structures. The primary source of the distortion appears to be formation of artifactual H-bonds, as has been repeatedly observed in vacuum simulations. To address such shortcomings, a recently proposed approach that has been developed for calculating the structure of segments that connect elements of secondary structure with known coordinates, is applied to 5-HT2AR to obtain an initial representation of the loops connecting the transmembrane (TM) helices. The approach consists of a simulated annealing combined with biased scaled collective variables Monte Carlo technique, and is applied to loops connecting the TM segments on both the extra-cellular and the cytoplasmic sides of the receptor. Although this initial calculation treats the loops as independent structural entities, the final structure exhibits a number of interloop interactions that may have functional significance. Finally, it is shown here that in the case where a given loop from two different GPCRs (here rhodopsin and 5-HT2AR) has approximately the same length and some degree of sequence identity, the fold adopted by the loops can be similar. Thus, in such special cases homology modeling might be used to obtain initial structures of these loops. Notably, however, all other loops in these two receptors appear to be very different in sequence and structure, so that their conformations can be found reliably only by ab initio, energy based methods and not by homology modeling.

Impact of industrial wastewater disposal on surface water bodies in Mostord area, north greater Cairo

The studied area (Shoubra El-Khima, Bahteem and Mostorod) lies in the industrial area north of Greater Cairo. The area suffers from several environmental problems such as sewage and disposal of pollutants from the surrounding factories into the surface water pathways in the area. Water samples were collected seasonally from different waterways found in the area, domestic and or industrial liquid wastes from 12 discharge tubes of different factories (as a point source of pollution). Chemical characteristics of different water samples and its heavy metals content were determined using ion coupled plasma technique (ICP). Results indicate that industrial and domestic wastewater samples contain several toxic levels of tested heavy metals (Cd, Co, Pb and Ni) which have a serious impact on surface waterways in the area. Shebin El-Qanater collector drain samples exhibited the highest levels of Cd, Co, Pb and Ni compared to other tested water bodies. Mostorod collector drain samples showed the highest levels of Zn and Cu. Industrial effluent samples collected from Cairo Company for Fabric industry had the highest amounts of total Zn Cu, Cd, Co and Pb, while Delta steel company discharges the highest amounts of total Fe and Mn. Al-Ahleya Plastic Company discharges the highest amounts of total-Ni. Generally, it is necessary to impose the environmental laws and its regulation regarding the industrial wastewater treatments and disposals to minimize the risk of the adverse effects of these pollutants.

Differences in conformational properties of the second intracellular loop (IL2) in 5HT(2C) receptors modified by RNA editing can account for G protein coupling efficiency

Adenosine-to-inosine RNA editing events that have been demonstrated for 5HT (2C) receptors resulted in alterations of the amino acid sequence at positions 156, 158 and 160 in the intracellular loop 2 (IL2) region. The edited receptor isoforms were shown to have reduced basal activity, but similar maximum responses to agonist binding. To identify the molecular mechanism of these pharmacological effects of editing we explored the conformational properties of the edited IL2 in comparison with the wild type. The results from conformational studies of the IL2 isoforms, using biased Monte Carlo simulations with an implicit solvent model based on a screened Coulomb potential, show that the compared loops differ in their preferred spatial orientations as a result of differences in the conformational space that is accessible to them by energy criteria. For the IL2 of the unedited (5HT (2C-INI) ) receptor, the preference for structures oriented towards the 7TM bundle is larger than for the 5HT (2C-VGV) edited receptor. This difference in preferred orientation can affect the association of IL2 with other intracellular loop domains involved in G protein coupling and hence the coupling efficiency. The results illustrate the high sensitivity of the system to small changes in the interaction surface presented to other intracellular loops, and/or the G protein.

Outcomes of noncardiac surgery after coronary bypass surgery or coronary angioplasty in the Bypass Angioplasty Revascularization Investigation (BARI)

PURPOSE

Previous studies have shown that coronary artery bypass surgery reduces the risk of cardiac complications after noncardiac surgery. Whether coronary angioplasty provides equivalent protection is not known.

SUBJECTS AND METHODS

Patients were randomly assigned to undergo cardiac artery bypass surgery or angioplasty as part of the Bypass Angioplasty Revascularization Investigation trial. All subsequent noncardiac surgeries during a mean (+/- SD) follow-up of 7.7 years were recorded among participants in the ancillary Study of Economics and Quality of Life. Rates of mortality and nonfatal myocardial infarction, length of stay, and hospital costs were compared by the original randomized assignment.

RESULTS

A total of 501 patients had noncardiac surgery at a median of 29 months after their most recent coronary revascularization procedure. Mortality and nonfatal myocardial infarction within 30 days of the first noncardiac surgery occurred in 4 of the 250 of the surgery-assigned patients and in 4 of the 251 of the angioplasty-assigned patients (P = 1.0). There were no significant differences in the mean length of hospital stay (6.3 +/- 6.7 versus 6.2 +/- 6.8 days; P = 0.47) or hospital cost ($8,920 +/- $11,511 versus $7,785 +/- $7,643; P = 0.33) between the surgery and angioplasty groups. Similar results were obtained when subsequent noncardiac procedures were included in the analysis.

CONCLUSION

Rates of myocardial infarction and death after noncardiac surgery are similarly low after contemporary bypass surgery or angioplasty in patients with multivessel coronary artery disease.

Optical properties of nonequilibrium low-dimensional systems

The optical properties of low-dimensional carrier systems ("quantum wire" type) driven away from equilibrium are studied. The frequency and wave-vector-dependent dielectric function of a quasi-one-dimensional electron system under the action of an exciting external pumping source is derived. The optical responses of the system are obtained in terms of its nonequilibrium thermodynamic state, the latter characterized resorting to a nonequilibrium statistical ensemble formalism.

Quality of life in HIV disease as measured by the McGill quality of life questionnaire

OBJECTIVE

To test the acceptability, validity, and internal consistency reliability of the McGill quality of life questionnaire (MQOL) for persons living with HIV/AIDS.

DESIGN

The validity of MQOL was tested by having HIV-seropositive outpatients complete the 16-item MQOL, a single-item scale (SIS) measuring overall quality of life (QOL), and a physical symptom questionnaire.

METHODS

Factor analysis was used as a guide for construction of MQOL subscales. Validity was studied by determining the correlation between MQOL and SIS, and between MQOL physical measures, CD4 counts and the physical symptoms questionnaire. Multiple regression was employed to determine how best to combine MQOL subscales to predict SIS.

RESULTS

MQOL was acceptable to this patient population. Factor analysis suggests that MQOL can be represented by live measures: a single item measuring physical well-being and four subscales representing physical symptoms, psychological symptoms, existential well-being, and support. Multiple regression analyses suggest that the existential domain contributes greatly to QOL for people with advanced HIV disease (CD4 counts < 100 x 10(6)/l).

CONCLUSION

MQOL is an acceptable and valid measure of QOL for people living with HIV/AIDS, with meaningful and reliable subscales as well as a summary score. The inclusion of a measure of existential well-being in MQOL may make it a more valid measure of QOL, especially for people with advanced disease, than QOL instruments which do not include this domain.

SA gene expression in the proximal tubule of normotensive and hypertensive rats

Previous studies have shown that the SA gene is expressed at higher levels in the kidney of genetically hypertensive rats than in control strains and that in hybrid crosses of genetically hypertensive rats and normotensive controls, markers in or close to the SA gene cosegregate with blood pressure. The present studies examine the localization of the SA gene product in the kidney by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). cDNA was prepared from microdissected nephron segments from Sprague-Dawley (SD) rats, spontaneously hypertensive rats (SHRs), and Wistar-Kyoto (WKY) rats, and RT-PCR was performed using specific primers. In all three strains, SA gene mRNA was found to be abundantly expressed in proximal tubules. SA PCR product was occasionally detected at approximately 100-fold lower abundance in glomeruli, while no signal was obtained from the collecting duct, thick ascending limb of the loop of Henle, or arcuate artery. Within the proximal tubule of normotensive rats, distribution of SA mRNA was found to be strain dependent: in SD rats it was expressed at high levels in the proximal convoluted tubule, whereas in WKY rats it was restricted to the proximal straight tubule. In SHRs, SA PCR product was detected along the entire proximal tubule. Induction of hypertension by renal artery clamping (two-kidney, one-clamp Goldblatt model) did not alter the pattern of expression observed in the SD rat. These results indicate that an extension of SA gene expression to the full length of the proximal tubule accompanies spontaneous hypertension and that in nonhypertensive animals the pattern of gene product expression is more restricted but shows substantial strain variability.

Factors that influence women's nutrition knowledge in Saudi Arabia

We studied knowledge of nutritional needs during pregnancy and lactation in 150 pregnant Saudi women at three primary health care centers in Riyadh, Saudi Arabia. We used an interview schedule to collect data regarding the women's knowledge and to determine the effects of certain independent variables on the knowledge scores. Green et al.'s (1980) PRECEDE model provided the theoretical framework for the study. Descriptive statistics, t test, and chi-square methods were used to analyze the data. The majority of the women had poor nutrition knowledge scores, with no significant differences among the three centers. A positive relationship was found between knowledge score and educational level. Negative relationships were found between knowledge score and number of pregnancies, number of deliveries, and number of living children. The findings have several implications for efforts to improve the health status of women in Saudi Arabia.

Serum strontium estimation as a diagnostic criterion of the type of drowning water

The estimation of serum strontium in rabbits before and after death by drowning, in soft or hard water, or by barbiturate intoxication is highly promising as a method in medicolegal practice. It not only diagnoses drowning but also indicates the type of drowning water. Atomic absorption spectrophotometry is a good method for the estimation.

Effects of reovirus type 1 on the developing mouse embryo

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