Rola sygnalizacji kisspeptyny w osi podwzgórze–przysadka–nadnercza — aktualna perspektywa

  The discovery of kisspeptins in the recent past remoulded current understanding of the neuroendocrine axis relating to the regulation of human puberty and reproduction. Kisspeptins have been recognised to act upstream of GnRH and have been shown to play a vital role in the control of the hypothalamic–pituitary–gonadal axis via regulation of gonadotrophin secretion, onset of puberty, and control of fertility. KNDy (kisspeptin/neurokinin-B/dynorphin) neurons have been suggested to modulate GnRH pulsatile secretion, which is required to support reproductive function in both sexes. They have also been involved in mediating both positive and negative sex steroid feedback signals to GnRH neurons and serve as a vital connection between reproduction and metabolic status of the body. When kisspeptin is administered to healthy humans, and in patients with reproductive disorders, it strongly and directly stimulates GnRH and subsequent LH secretion and enhances LH pulse frequency. These observations suggest that kisspeptins are a potential novel therapeutic approach for treating disorders with either pathologically reduced or augmented gonadotrophins pulsatile secretion and is currently a focus of translational research. Kisspeptins have also been identified in several peripheral reproductive organs, indicating their role in modulation of ovarian function, embryo implantation, and placentation, but a great deal of work remains to be done to explore further in this regard, and the evidence is only available from studies done on animal models. In this review we will mainly focus on current available evidence related to the role of kisspeptins in controlling GnRH pulse frequency, specifically their role in puberty, fertility, and reproduction. We will also be appraising other factors that regulate the kiSS1/Kisspeptin/GPR-54 system. (Endokrynol Pol 2015; 66 (6): 534–547)    Odkrycie kisspeptyn, które miało miejsce całkiem niedawno, odmieniło obecne rozumienie osi neuroendokrynnej, związanej z regulacją okresu dojrzewania i rozrodu. Odkryto, że kisspeptyny działają przed GnRH i odgrywają istotną rolę w kontroli osi podwzgórze–przysadka– nadnercza poprzez regulację wydzielania gonadotropiny, rozpoczęcia okresu dojrzewania oraz kontroli płodności. Zasugerowano, że komórki KNDy (kisspeptyna/neurokinina-B/dynorfina) modulują pulsacyjne uwalnianie GnRH, wymagane, aby wspomagać funkcję rozrodczą u obu płci. Komórki te są również zaangażowane w przekazywanie zarówno pozytywnych, jak i negatywnych sygnałów hormonów płciowych do neuronów GnRH, a także stanowią kluczowe połączenie między reprodukcją i stanem metabolicznym ciała. Kiedy kisspeptyna jest podawana jednostkom zdrowym i pacjentom z zaburzeniami płodności, silnie i bezpośrednio stymuluje GnPH i dalsze uwalnianie LH oraz poprawia częstotliwość impulsów LH. Obserwacje te przedstawiają kisspeptyny jako nowe potencjalne terapeutyczne podejście w leczeniu zaburzeń patologicznie obniżonego lub zwiększonego pulsacyjnego uwalniania gonadotropin i obecnie stanowi główny punkt zainteresowania badań przekładających się na zastosowanie praktyczne. Kisspeptyny zidentyfikowano także w kilku organach obwodowych, uczestnicząc w modulacji czynności jajników, implantacji zarodka oraz placentacji, lecz dalsze badania w tym kierunku będą wymagały jeszcze wiele wysiłku, a dowody można uzyskać jedynie z badań przeprowadzanych na modelach zwierzęcych. W niniejszej pracy autorzy skupili się głównie na obecnie dostępnych dowodach związanych z rolą kisspeptyn w kontrolowaniu częstotliwości impulsów GnRH, a zwłaszcza ich rolą w okresie dojrzewania, płodności oraz reprodukcji. W niniejszym artykule poddano ocenie także inne czynniki regulujące system kiSS1/Kisspeptin/GPR-54. (Endokrynol Pol 2015; 66 (6): 534–547)

spectrum of acquired demyelinating disorders of the central nervous system in adults in a tertiary care hospital

Acquired demyelinating disorders of the central nervous system are diverse group of conditions characterized by destruction or disturbance of myelin sheath in the central nervous system i.e. brain and spinal cord. These vary in their causes, clinical presentations, and prognosis

Phylogenetics of HCV: Recent advances

Hepatitis C virus (HCV), a virus present in human population from indefinite time period, has affected millions of people globally, by causing liver infection which in majority of cases leads to chronicity, cirrhosis, end stage liver disease and hepatocellular carcinoma (HCC). The disease burden is expected to increase in the developing and under developed world in future. The distribution of HCV genotypes is changing, as are the modes of transmission. Evolution of HCV is a highly dynamic process as it exploits all known mechanisms of genetic variation including recombination and mutation, to ensure its survival. It occurs both through multiple processes of adaptive selection that drive sequence change and through drift, in which phenotypically neutral sequence changes accumulate over time without altering the phenotype or behaviour of the virus. However, despite its potential to change rapidly, the longer-term evolution of HCV appears to be remarkably conservative. Phylogenetic and statistical models of viral evolution are useful in reconstructing mutational pathways of drug resistance. The two major divisions of viral heterogeneity include genotypes and quasispecies. The rate of nucleotide changes varies significantly among the different regions of the viral genome. The present HCV classification is incomplete, as new genotypes and variants are being identified till yet. Diversification of HCV occurred over time but with different rates. Host immune pressure is thought to be a main factor driving diversification in HCV quasispecies. Core and hypervariable regions are more diverse while 5' un-translated region (UTR) and 3' UTR are highly conserved across the genotypes.Keywords: HCV, phylogeny, 5' UTR, viral evolution, recombination, quasispeciesAfrican Journal of Biotechnology Vol. 9(36), pp. 5792-5799, 6 September, 201

Impact of Fiber Duplication on Protection Architectures Feasibility for Passive Optical Networks

Adaptability of high capacity passive optical network (PON) requires the provision of an efficient fault detection and restoration mechanism throughout the network at an acceptable cost. The readily adapted pre-planned protection strategy relies on component duplication, which significantly increases the cost of deployment for PON. Therefore, it is imperative to determine a suitable component that requires high redundancy and determine the impact of protection for that component on feasibility of PON. Five protection architecture including ITU-T 983.1 Type C, single ring, dual ring, tree- and ring-based architectures with hybrid star-ring topology at the optical distribution network (ODN), are considered to evaluate the impact of fiber duplication in terms of capital expenditure (CAPEX), operation expenditure (OPEX), reliability, and support for maximum number of subscribers. Reliability block diagram (RBD) based analysis shows that desirable 5 nines connection availability is provided by each protection architecture and utilization of ring topology avoids duplication of the fiber but effects the number of subscribers. Furthermore, it is observed that OF duplication at ODN is the main contributor to CAPEX. Collectively hybrid protection architectures provide efficient performance and proves to be a feasible solution for the deployment of survivable PONs at the access domain

Self-Concept, Self- Affirmation and Psychological Distress in Women with Polycystic Ovarian Syndrome (PCOS)

To study the relationship among self-concept, self- affirmation and psychological distress in females having Polycystic Ovary Syndrome (PCOS). In this correlational study one hundred patients with polycystic ovarian syndrome participated with age ranging from 21-40 years. Self-Concept questionnaire, self-Affirmation scale, and Kessler psychological distress scale were used to collect data The results of this study revealed that negative-self-concept has significantly positive relationship with psychological distress. Multiple regression revealed that positive self-concept negatively predicted psychological distress in females having polycystic ovarian disease. Independent sample t=test revealed that psychological distress is more in married women (M= 32.96, SD=8.60) as compared to single women (M=28.12, SD, 8.14). It was concluded that negative self-concept has positive association with psychological distress while self-affirmation is negatively correlated with psychological distress

Association of Interleukin-6 Gene Promoter Polymorphism with Coronary Artery Disease in Pakistani Families

Interleukin-6 (IL-6) is a well-known inflammatory cytokine and suggested to be involved in the development of coronary artery disease (CAD). IL-6 gene expression has been investigated with controversy in CAD patients. This study investigates the association of the IL-6 gene expression with CAD, the molecular basis for the regulation of interleukin-6 expression in a Pakistani population. Our data show that the serum IL-6 levels were increased in patients with CAD compared with healthy controls and that the IL-6 gene polymorphism at -174 was more prevalent in CAD cases. There was a statistically significant association between the IL-6 gene polymorphism and CAD, which may be associated with an increased risk for the disease. Moreover, circulating IL-6 and hs-CRP levels were significantly higher in patients with CC genotype (PC polymorphism. This is the first report on the IL-6 expression and the IL-6 gene polymorphism in patients with CAD from Pakistan, and hence it highlights a novel risk factor for the disease

Comparative Study of Single- Versus Split-Dose Polyethylene Glycol Electrolyte Solution Before Undergoing Colonoscopy

Objective: To compare the outcome of consumption of a single versus split-dose polyethylene glycol electrolyte solution in patients undergoing colonoscopy in the morning. Methodology: A randomised controlled trial was conducted at the Department of Gastroenterology, Sir Ganga Ram Hospital, Lahore, from April to July 2021. A total of 274 patients undergoing colonoscopy, who fulfilled the selection criteria were included through a "non-probability, consecutive sampling technique". The patients were randomly divided into two groups. In group A, single dose of PEG was administered. Group B was administered a split dose of PEG which was to be consumed in two parts, 1st in evening before colonoscopy and the second in the morning. Efficacy was labelled if adequate cleaning of the intestines and a BBPS score of ≥6 were achieved during colonoscopy. Results:  In the single dose group, the mean age of patients was 45.15 ± 13.37 years, 68 (49.6%) patients were male, 69 (50.4%) patients were female, efficacy of the procedure was achieved in 54 (39.4%) patients, and the mean BBPS score was 4.99 ± 0.90. In the split dose group, mean age of patients was 49.85 ± 11.38 years, 56 (40.9%) patients were male, 81 (59.1%) patients were female, efficacy of the procedure was achieved in 137 (100%) patients, and the mean BBPS score was 7.61 ± 0.49. The difference in both groups was highly significant (p-value < 0.0001). Conclusion: A split dose is thus more efficacious and acceptable than a single dose of polyethylene glycol electrolyte solution given for bowel preparation

WORKPLACE BULLYING: CASE STUDY OF PUBLIC SECTOR UNIVERSITY

Workplace bullying is an amalgamation of negative behaviors of varying intensity that can severely damage one‟s ability to work effectively or efficiently. The study aims to examine the prevalence, forms and perceived perpetrator(s) of workplace bullying in a public sector university, ultimately highlighting the existing policies and procedures aiming to discourage the practice of workplace bullying at an organizational level. The study adopts a mixed method strategy. A two-step sampling approach is adopted for gathering quantitative data, where stratified sampling was followed by simple random sampling technique. For qualitative data, purposive sampling is used. The study identifies that workplace bullying prevails among university‟s faculty members where more than half of the respondents were exposed to it. The perceived perpetrators were mostly male employees targeting male employees on the same  hierarchical level. Also, faculty members belonging from the middle age and those who are at the middle of their career experienced highest exposure to bullying at work

Design and Analysis of Self-Healing Tree-Based Hybrid Spectral Amplitude Coding OCDMA System

This paper presents an efficient tree-based hybrid spectral amplitude coding optical code division multiple access (SAC-OCDMA) system that is able to provide high capacity transmission along with fault detection and restoration throughout the passive optical network (PON). Enhanced multidiagonal (EMD) code is adapted to elevate system’s performance, which negates multiple access interference and associated phase induced intensity noise through efficient two-matrix structure. Moreover, system connection availability is enhanced through an efficient protection architecture with tree and star-ring topology at the feeder and distribution level, respectively. The proposed hybrid architecture aims to provide seamless transmission of information at minimum cost. Mathematical model based on Gaussian approximation is developed to analyze performance of the proposed setup, followed by simulation analysis for validation. It is observed that the proposed system supports 64 subscribers, operating at the data rates of 2.5 Gbps and above. Moreover, survivability and cost analysis in comparison with existing schemes show that the proposed tree-based hybrid SAC-OCDMA system provides the required redundancy at minimum cost of infrastructure and operation

Potent Implications of miRNA in Cancer Biology – A Brief Review

Groundbreaking findings through high-throughput technologies have deepened our understanding on an intricate interplay between products of coding sequences and noncoding RNAs. Increasingly it is being realized that miRNA, produced from what was previously considered as "genomic trash" have revolutionized the field of molecular and translational oncology. Overwhelmingly accumulating in-vitro and in-vivo studies have demonstrated that miRNA are key players involved in post-transcriptional regulation of gene network in numerous human pathologies including cancer. In this review we have attempted to provide recent advancements related to multifaceted roles played by miRNA in modulation of oncogenes and tumor suppressor genes