Novel Nuclear Roles for Testis-Specific ACTL7A and ACTL7B Supported by In Vivo Characterizations and AI Facilitated In Silico Mechanistic Modeling with Implications for Epigenetic Regulation in Spermiogenesis

A mechanistic role for nuclear function of testis-specific actin related proteins (ARPs) is proposed here through contributions of ARP subunit swapping in canonical chromatin regulatory complexes. This is significant to our understanding of both mechanisms controlling regulation of spermiogenesis, and the expanding functional roles of the ARPs in cell biology. Among these roles, actins and ARPs are pivotal not only in cytoskeletal regulation, but also in intranuclear chromatin organization, influencing gene regulation and nucleosome remodeling. This study focuses on two testis-specific ARPs, ACTL7A and ACTL7B, exploring their intranuclear activities and broader implications utilizing combined in vivo, in vitro, and in silico approaches. ACTL7A and ACTL7B, previously associated with structural roles, are hypothesized here to serve in chromatin regulation during germline development. This study confirms the intranuclear presence of ACTL7B in spermatocytes and round spermatids, revealing a potential role in intranuclear processes, and identifies a putative nuclear localization sequence conserved across mammalian ACTL7B, indicating a potentially unique mode of nuclear transport which differs from conventional actin. Ablation of ACTL7B leads to varied transcriptional changes reported here. Additionally, in the absence of ACTL7A or ACTL7B there is a loss of intranuclear localization of HDAC1 and HDAC3, which are known regulators of epigenetic associated acetylation changes that in turn regulate gene expression. Thus, these HDACs are implicated as contributors to the aberrant gene expression observed in the KO mouse testis transcriptomic analysis. Furthermore, this study employed and confirmed the accuracy of in silico models to predict ARP interactions with Helicase-SANT-associated (HSA) domains, uncovering putative roles for testis-specific ARPs in nucleosome remodeling complexes. In these models, ACTL7A and ACTL7B were found capable of binding to INO80 and SWI/SNF nucleosome remodeler family members in a manner akin to nuclear actin and ACTL6A. These models thus implicate germline-specific ARP subunit swapping within chromatin regulatory complexes as a potential regulatory mechanism for chromatin and associated molecular machinery adaptations in nuclear reorganizations required during spermiogenesis. These results hold implications for male fertility and epigenetic programing in the male-germline that warrant significant future investigation. In summary, this study reveals that ACTL7A and ACTL7B play intranuclear gene regulation roles in male gametogenesis, adding to the multifaceted roles identified also spanning structural, acrosomal, and flagellar stability. ACTL7A and ACTL7B unique nuclear transport, impact on HDAC nuclear associations, impact on transcriptional processes, and proposed mechanism for involvement in nucleosome remodeling complexes supported by AI facilitated in silico modeling contribute to a more comprehensive understanding of the indispensable functions of ARPs broadly in cell biology, and specifically in male fertility.

Flavone and Hydroxyflavones Are Ligands That Bind the Orphan Nuclear Receptor 4A1 (NR4A1)

It was recently reported that the hydroxyflavones quercetin and kaempferol bind the orphan nuclear receptor 4A1 (NR4A1, Nur77) and act as antagonists in cancer cells and tumors, and they inhibit pro-oncogenic NR4A1-regulated genes and pathways. In this study, we investigated the interactions of flavone, six hydroxyflavones, seven dihydroxyflavones, three trihydroxyflavones, two tetrahydroxyflavones, and one pentahydroxyflavone with the ligand-binding domain (LBD) of NR4A1 using direct-binding fluorescence and an isothermal titration calorimetry (ITC) assays. Flavone and the hydroxyflavones bound NR4A1, and their KD values ranged from 0.36 µM for 3,5,7-trihydroxyflavone (galangin) to 45.8 µM for 3'-hydroxyflavone. KD values determined using ITC and KD values for most (15/20) of the hydroxyflavones were decreased compared to those obtained using the fluorescence assay. The results of binding, transactivation and receptor-ligand modeling assays showed that KD values, transactivation data and docking scores for these compounds are highly variable with respect to the number and position of the hydroxyl groups on the flavone backbone structure, suggesting that hydroxyflavones are selective NR4A1 modulators. Nevertheless, the data show that hydroxyflavone-based neutraceuticals are NR4A1 ligands and that some of these compounds can now be repurposed and used to target sub-populations of patients that overexpress NR4A1.

Actin-related protein ACTL7B ablation leads to OAT with multiple morphological abnormalities of the flagellum and male infertility in mice†

The formation of fertilisation-competent sperm requires spermatid morphogenesis (spermiogenesis), a poorly understood program that involves complex coordinated restructuring and specialised cytoskeletal structures. A major class of cytoskeletal regulators are the actin-related proteins (ARPs), which include conventional actin variants, and related proteins that play essential roles in complexes regulating actin dynamics, intracellular transport, and chromatin remodeling. Multiple testis-specific ARPs are well conserved among mammals, but their functional roles are unknown. One of these is actin-like 7b (Actl7b) that encodes an orphan ARP highly similar to the ubiquitously expressed beta actin (ACTB). Here we report ACTL7B is expressed in human and mouse spermatids through the elongation phase of spermatid development. In mice, ACTL7B specifically localises to the developing acrosome, within the nucleus of early spermatids, and to the flagellum connecting region. Based on this localisation pattern and high level of sequence conservation in mice, humans, and other mammals, we examined the requirement for ACTL7B in spermiogenesis by generating and characterising the reproductive phenotype of male Actl7b KO mice. KO mice were infertile, with severe and variable oligoteratozoospermia (OAT) and multiple morphological abnormalities of the flagellum (MMAF) and sperm head. These defects phenocopy human OAT and MMAF, which are leading causes of idiopathic male infertility. In conclusion, this work identifies ACTL7B as a key regulator of spermiogenesis that is required for male fertility.

Testis-specific actin-like 7A (ACTL7A) is an indispensable protein for subacrosomal-associated F-actin formation, acrosomal anchoring, and male fertility

Formation of the acrosome during spermiogenesis is an essential process for creating fertilization-competent sperm. Of the numerous aspects required for acrosome biogenesis, adherence of the acrosomal outer membrane to the nuclear surface is mediated by the subacrosomal perinuclear theca. However, the cellular dynamics and congruent functions pertaining to these acrosomal anchoring factors are not well understood despite many of them being implicated as potential causes for human male infertility. Actin-like 7A (ACTL7A) is one such factor for which deleterious polymorphisms have recently been shown to cause human male infertility. It is thought that acrosomal attachment is coordinated by cytoskeletal associations between the acrosome and nucleus via the acroplaxome. To further illuminate the mechanistic underpinnings of ACTL7A for essential acrosome associations, in this study, we investigated its dynamic localization in the developing germline, molecular associations with other cytoskeletal components, and the cellular consequences of ablation. Our intracellular localization data show ACTL7A to be dynamically present within the nucleus and subacrosomal space and later associated with postacrosomal regions of developing spermatids. Through the generation of an Actl7a knock-out mouse model, we consistently observed disruption of acrosomal biogenesis with abnormal migration of the acrosomal granule and peeling acrosomes during spermatid elongation. Significantly, we found a complete loss of subacrosomal filamentous actin (F-actin) structures in knock-out spermatids suggesting a regulatory role for subacrosomal F-actin. Considering our reported data together with existing literature, we propose a mechanistic model explaining the essential role of ACTL7A for acroplaxome-associated F-actin, acrosomal attachment integrity, and male fertility.

Emergence Time and Sequence of Primary Teeth in a Sample of Nepalese Children

Background Primary teeth emergence is an important milestone in children and timing of emergence varies among populations. Objective To determine the emergence time and sequence of primary teeth in a sample of Nepalese children visiting Dhulikhel Hospital. Method A descriptive cross-sectional study was conducted in children of 5 months to 4 years visiting Dhulikhel Hospital. The emergence of incisal tip to incisal margin for incisors and canines, cusp tip to occlusal margin of molars visible were recorded along with age in months and gender. Descriptive statistics was done to calculate the mean age of emergence of each tooth with standard deviation. Unpaired t-test was used to assess the difference between the mean age of emergence of teeth between right and left sides and between boys and girls. Result The first teeth to emerge was mandibular central incisor at the age of 9.37 ± 1.42 months and the last one was maxillary second molar at the age of 32.91 ± 6.39 months. There was no significant difference in the mean emergence time between the maxillary and mandibular jaws, between right and left sides of jaws and between boys and girls except for primary maxillary right central incisor and mandibular right second molar which was found to be emerged early in girls. Conclusion The emergence time and sequence of primary teeth observed in the present study can be used as a baseline data for the children of Kavre district.

Hmga2 deficiency is associated with allometric growth retardation, infertility, and behavioral abnormalities in mice

The high mobility group AT-hook 2 (HMGA2) protein works as an architectural regulator by binding AT-rich DNA sequences to induce conformational changes affecting transcription. Genomic deletions disrupting HMGA2 coding sequences and flanking noncoding sequences cause dwarfism in mice and rabbits. Here, CRISPR/Cas9 was used in mice to generate an Hmga2 null allele that specifically disrupts only the coding sequence. The loss of one or both alleles of Hmga2 resulted in reduced body size of 20% and 60%, respectively, compared to wild-type littermates as well as an allometric reduction in skull length in Hmga2-/- mice. Both male and female Hmga2-/- mice are infertile, whereas Hmga2+/- mice are fertile. Examination of reproductive tissues of Hmga2-/- males revealed a significantly reduced size of testis, epididymis, and seminal vesicle compared to controls, and 70% of knock-out males showed externalized penis, but no cryptorchidism was observed. Sperm analyses revealed severe oligospermia in mutant males and slightly decreased sperm viability, increased DNA damage but normal sperm chromatin compaction. Testis histology surprisingly revealed a normal seminiferous epithelium, despite the significant reduction in testis size. In addition, Hmga2-/- mice showed a significantly reduced exploratory behavior. In summary, the phenotypic effects in mouse using targeted mutagenesis confirmed that Hmga2 is affecting prenatal and postnatal growth regulation, male reproductive tissue development, and presents the first indication that Hmga2 function is required for normal mouse behavior. No specific effect, despite an allometric reduction, on craniofacial development was noted in contrast to previous reports of an altered craniofacial development in mice and rabbits carrying deletions of both coding and noncoding sequences at the 5' part of Hmga2.

Translation and Validation of Oral Health-Related Early Childhood Quality of Life Tool for Nepalese Preschool Children

Background Early childhood caries (ECC) in preschool children debilitate their quality of life affecting oral function, appearance and social well-being. A tool for measuring oral health-related quality of life for preschoolers may help in making clinical decisions and assist policy makers in planning and management of health programs in the country. Objective To translate oral health-related early childhood quality of life (OH-ECQoL) tool into Nepali language and test its validity and reliability. Method OH-ECQoL was translated into Nepali language by two Nepalese professional translators which was back translated by professional English translator. This was sent to three independent advisors to see the appropriateness of translation. Pilot testing was done in 20 parents and questionnaire was finalized after needed corrections. Final version was introduced to the 118 parents of children aged 24- 71 months. Caries status was recorded for all children participating in the study. Concurrent, construct, discriminant validity and internal consistency reliability, test -retest reliability were evaluated. Result OH-ECQoL scores and perception of parents for general and oral health of their children was significant (at 0.01 level). There was significant difference in OH-ECQoL scores between no ECC and severe ECC groups and moderate and severe ECC groups (at 0.05 level). There was also a significant correlation between child impact section and family impact section (at 0.01 level). Cronbach's alpha was 0.891 demonstrating good internal consistency. Intra class coefficient was 0.963 suggesting excellent testretest reliability. Ninety-one (77.1%) children had severe ECC and 40(33.9%) parents were from upper middle class. Conclusion The Nepali version of OH-ECQoL is a valid and reliable tool for assessing the oral health-related early childhood quality of life in children of Nepal.

Activation of Meiotic Genes Mediates Ploidy Reduction during Cryptococcal Infection

Cryptococcus neoformans is a global human fungal pathogen that causes fatal meningoencephalitis in mostly immunocompromised individuals. During pulmonary infection, cryptococcal cells form large polyploid cells that exhibit increased resistance to host immune attack and are proposed to contribute to the latency of cryptococcal infection. These polyploid titan cells can generate haploid and aneuploid progeny that may result in systemic infection. What triggers cryptococcal polyploidization and how ploidy reduction is achieved remain open questions. Here, we discovered that Cryptococcus cells polyploidize in response to genotoxic stresses that cause DNA double-strand breaks. Intriguingly, meiosis-specific genes are activated in C. neoformans and contribute to ploidy reduction, both in vitro and during infection in mice. Cryptococcal cells that activated their meiotic genes in mice were resistant to specific genotoxic stress compared to sister cells recovered from the same host tissue but without activation of meiotic genes. Our findings support the idea that meiotic genes, in addition to their conventional roles in classic sexual reproduction, contribute to adaptation of eukaryotic cells that undergo dramatic genome changes in response to genotoxic stress. The discovery has additional implications for evolution of sexual reproduction and the paradox of the presence of meiotic machinery in asexual species. Finally, our findings in this eukaryotic microbe mirror the revolutionary discoveries of the polyploidization and meiosis-like ploidy reduction process in cancer cells, suggesting that the reversible ploidy change itself could provide a general mechanism for rejuvenation to promote individual survival in response to stress.

Tuberculosis and the art of macrophage manipulation

Macrophages are first-line responders against microbes. The success of Mycobacterium tuberculosis (Mtb) rests upon its ability to convert these antimicrobial cells into a permissive cellular niche. This is a remarkable accomplishment, as the antimicrobial arsenal of macrophages is extensive. Normally bacteria are delivered to an acidic, degradative lysosome through one of several trafficking pathways, including LC3-associated phagocytosis (LAP) and autophagy. Once phagocytozed, the bacilli are subjected to reactive oxygen and nitrogen species, and they induce the expression of proinflammatory cytokines, which serve to augment host responses. However, Mtb hijacks these host defense mechanisms, manipulating host cellular trafficking, innate immune responses, and cell death pathways to its benefit. The complex series of measures and countermeasures between host and pathogen ultimately determines the outcome of infection. In this review, we focus on the diverse effectors that Mtb uses in its multipronged effort to subvert the innate immune responses of macrophages. We highlight recent advances in understanding the molecular interface of the Mtb-macrophage interaction.

Developing tool and Measuring Integration Characteristics of Basic Science Curriculum to Improve Curriculum Integration

Background Integrated curriculum enhances students' learning and the retention of knowledge. At Patan Academy of Health Sciences, integrated organ system based curriculum is used with Problem Based Learning as the principle teaching learning method to foster students' learning. In addition, other approaches of integration were under taken such as integrated assessment; logical arrangement teaching learning methods (lectures and practicals); joint effort of faculty in curriculum planning and delivery; conducive environment to foster hidden curriculum. This study describes the perception of faculty and students on integration characteristics of Basic Science curriculum. Objective To measure the integration characteristics of Basic Science Curriculum. Method Tool was developed to measure integration characteristics of Basic Science Curriculum and ensure whether such planned integration has been achieved. Mixed method was used to measure the perception of the integration characteristics i) quantitatively by questionnaire survey to faculty and students ii) qualitatively by in-depth interview of students. Result Both faculty and students perceived that all the blocks in Basic Science was well integrated in the quantitative questionnaire survey. But, in the in-depth interview, students perceived integration of curriculum in organ system blocks were better integrated compared to Principle of Human Biology blocks where fundamentals of basic science disciplines were delivered. Students reflected that Problem Based Learning not only integrated Basic Science disciplines but also with clinical sciences and the social context. But, students perceived that Community Health Sciences curriculum was not so well integrated with Basic Science subjects. Conclusion Overall, this study showed that planned integration in Basic Science curriculum was successfully executed during curriculum implementation.

Assessing the Relationship of Maternal Factors and Family Income with Early Childhood Caries: A Hospital Based Study

Background Earlychildhood caries (ECC) is a multifactorial disease. Maternal factors and family income has major influence on the caries status of children. Objective To assess the relationship of maternal factors and family income with early childhood caries among children attending Pediatric Dentistry department of Dhulikhel Hospital. Method A cross sectional study was conducted among 239 children of age 3 to 6 years attending Pediatric Dentistry department of Dhulikhel Hospital, Kavre, Nepal. Age of child, mother's occupational status,educational level and family income were recorded. Oral examination of child was done to record decayed, missing, filled teeth (dmft). Descriptive analysis was done to observe the caries experience. Chi - square test was used to assess the relationship of caries experience with occupational status, education of mother and family income. Result The mean decayed, missing, filled teeth of the children was7.04±4.10. There was no significant relationship of early childhood caries with occupational status of mother (p=0.675), education of mother (p=0.140) and family income (p=0.158). Conclusion There was no relationship of maternal factors and family income with early childhood caries when surveyed among the children visiting Pediatric Dentistry department of Dhulikhel hospital.

Pheromone independent unisexual development in Cryptococcus neoformans

The fungus Cryptococcus neoformans can undergo a-α bisexual and unisexual reproduction. Completion of both sexual reproduction modes requires similar cellular differentiation processes and meiosis. Although bisexual reproduction generates equal number of a and α progeny and is far more efficient than unisexual reproduction under mating-inducing laboratory conditions, the α mating type dominates in nature. Population genetic studies suggest that unisexual reproduction by α isolates might have contributed to this sharply skewed distribution of the mating types. However, the predominance of the α mating type and the seemingly inefficient unisexual reproduction observed under laboratory conditions present a conundrum. Here, we discovered a previously unrecognized condition that promotes unisexual reproduction while suppressing bisexual reproduction. Pheromone is the principal stimulus for bisexual development in Cryptococcus. Interestingly, pheromone and other components of the pheromone pathway, including the key transcription factor Mat2, are not necessary but rather inhibitory for Cryptococcus to complete its unisexual cycle under this condition. The inactivation of the pheromone pathway promotes unisexual reproduction despite the essential role of this pathway in non-self-recognition during bisexual reproduction. Nonetheless, the requirement for the known filamentation regulator Znf2 and the expression of hyphal or basidium specific proteins remain the same for pheromone-dependent or independent sexual reproduction. Transcriptome analyses and an insertional mutagenesis screen in mat2Δ identified calcineurin being essential for this process. We further found that Znf2 and calcineurin work cooperatively in controlling unisexual development in this fungus. These findings indicate that Mat2 acts as a repressor of pheromone-independent unisexual development while serving as an activator for a-α bisexual development. The bi-functionality of Mat2 might have allowed it to act as a toggle switch for the mode of sexual development in this ubiquitous eukaryotic microbe.

An Experience of Pediatric Upper and Lower Gastrointestinal Endoscopy in a Tertiary Center

Background Although upper gastrointestinal endoscopy and colonoscopy is considered to be a gold standard in the diagnosis of many pediatric gastrointestinal disorders, there is limited data about its utility from our country. This important diagnostic tool is underutilized. Objective The objective of this study is to report the common indications, endoscopic findings and complications of pediatric upper gastrointestinal endoscopy and colonoscopy in a tertiary center to increase awareness amongst pediatricians. Methods This descriptive cross-sectional study was conducted in children undergoing upper gastrointestinal endoscopy and colonoscopy for various indications in a tertiary center from November 2014 to October 2016 (24 months). Results We performed 192 endoscopies during this period. Upper gastrointestinal endoscopy 158 and Colonoscopy 34. Mean age of patients was 10.2 years (range 6 months to 16 years) and 140(72.9%) patients were under 10 years of age. Common indications of UGI endoscopy were recurrent abdominal pain (67%), acute abdominal pain (12.6%), recurrent vomiting (8.0%), upper GI bleed (4.4%), failure to thrive (3.1%) and caustic ingestion (2.5%). An abnormality was detected in 128(81%) patients. Antral gastritis (55%) was the most common diagnosis. Thirty two percent of children with RAP had chronic moderate to severe gastritis and were positive for H. pylori in Giemsa stain on histopathological examination. Common indications of colonoscopy were Lower GI bleed and chronic diarrhea. Out of 22 patients who underwent colonoscopy for lower GI bleed, 18(82%) patients had rectal polyp and underwent snare polypectomy. Out of 12 patients who were evaluated for chronic diarrhea, 7(20%) were diagnosed to have cow's milk protein allergy and 5(15%) patients had inflammatory bowel disease. An abnormality was detected in 30(88%) patients. All children received sedation/ analgesia and tolerated the procedure well. Conclusion Upper gastrointestinal endoscopy and colonoscopy are safe procedure in children. The awareness about its diagnostic and therapeutic role should be raised amongst pediatricians in developing countries. There is also a need to develop training programs of pediatric gastroenterology and pediatric endoscopic suites in developing countries so that children may benefit from this state of the art diagnostic modality.

Permanent Teeth Emergence Time and Sequence in Children of Kavre District, Nepal

Background Population specific standards on the timing and sequence of emergence of permanent teeth are essential in planning dental care for children. There is only a single study on the emergence of permanent teeth in Nepalese children. Objective To determine the standards for permanent teeth emergence time and sequence in children of Kavre district, Nepal. Method A descriptive cross sectional study was conducted in 623 children of age 5 to 14 years from six different schools of Kavre district. The number of permanent tooth erupted except third molar was recorded along with age and gender. Data were analysed using SPSS 20.0. Descriptive statistics was used to determine the number and percentage of permanent teeth emerged at different ages and the mean age of emergence of each tooth. Student 't' test was used to determine the inter jaw differences in the mean age of emergence of each tooth. Result The study population constituted 50.7% boys and 49.3% girls of the total sample. The first tooth to emerge was mandibular first molar, whereas maxillary second molar tended to be the last to emerge in both the genders. Though in general, mandibular teeth tended to precede the corresponding maxillary teeth in emergence but significantly only mandibular central, lateral and second premolar emerged earlier than maxillary.( p ≤ 0.05) Conclusion This study can be used as a reference data for clinical and academic purpose especially for the children of Kavre district, Nepal.

Gentiana lutea exerts anti-atherosclerotic effects by preventing endothelial inflammation and smooth muscle cell migration

BACKGROUND AND AIMS

Studies suggest that Gentiana lutea (GL), and its component isovitexin, may exhibit anti-atherosclerotic properties. In this study we sought to investigate the protective mechanism of GL aqueous root extract and isovitexin on endothelial inflammation, smooth muscle cell migation, and on the onset and progression of atherosclerosis in streptozotocin (STZ)-induced diabetic rats.

METHODS AND RESULTS

Our results show that both GL extract and isovitexin, block leukocyte adhesion and generation of reactive oxygen species in human umbilical vein endothelial cells (HUVECs) and rat aortic smooth muscle cells (RASMCs), following TNF-alpha and platelet derived growth factor-BB (PDGF-BB) challenges respectively. Both the extract and isovitexin blocked TNF-α induced expression of ICAM-1 and VCAM-1 in HUVECs. PDGF-BB induced migration of RASMCs and phospholipase C-γ activation, were also abrogated by GL extract and isovitexin. Fura-2 based ratiometric measurements demonstrated that, both the extact, and isovitexin, inhibit PDGF-BB mediated intracellular calcium rise in RASMCs. Supplementation of regular diet with 2% GL root powder for STZ rats, reduced total cholesterol in blood. Oil Red O staining demonstrated decreased lipid accumulation in aortic wall of diabetic animals upon treatment with GL. Medial thickness and deposition of collagen in the aortic segment of diabetic rats were also reduced upon supplementation. Immunohistochemistry demonstrated reduced expression of vascular cell adhesion molecule-1 (VCAM-1), inducible nitric oxide synthase (iNOS), and vascular endothelial cadherin (VE-cadherin) in aortic segments of diabetic rats following GL treatment.

CONCLUSIONS

Thus, our results support that GL root extract/powder and isovitexin exhibit anti-atherosclerotic activities.

Subcellular Compartmentalization and Trafficking of the Biosynthetic Machinery for Fungal Melanin

Protection by melanin depends on its subcellular location. Although most filamentous fungi synthesize melanin via a polyketide synthase pathway, where and how melanin biosynthesis occurs and how it is deposited as extracellular granules remain elusive. Using a forward genetic screen in the pathogen Aspergillus fumigatus, we find that mutations in an endosomal sorting nexin abolish melanin cell-wall deposition. We find that all enzymes involved in the early steps of melanin biosynthesis are recruited to endosomes through a non-conventional secretory pathway. In contrast, late melanin enzymes accumulate in the cell wall. Such subcellular compartmentalization of the melanin biosynthetic machinery occurs in both A. fumigatus and A. nidulans. Thus, fungal melanin biosynthesis appears to be initiated in endosomes with exocytosis leading to melanin extracellular deposition, much like the synthesis and trafficking of mammalian melanin in endosomally derived melanosomes.

Neurospora crassa ASM-1 complements the conidiation defect in a stuA mutant of Aspergillus nidulans

Aspergillus nidulans StuA and Neurospora crassa ASM-1 are orthologous APSES (ASM-1, PHD1, SOK2, Efg1, StuA) transcription factors conserved across a diverse group of fungi. StuA and ASM-1 have roles in asexual (conidiation) and sexual (ascospore formation) development in both organisms. To address the hypothesis that the last common ancestor of these diverse fungi regulated conidiation with similar genes, asm-1 was introduced into the stuA1 mutant of A. nidulans. Expression of asm-1 complemented defective conidiophore morphology and restored conidia production to wild type levels in stuA1. Expression of asm-1 in the stuA1 strain did not rescue the defect in sexual development. When the conidiation regulator AbaA was tagged at its C-terminus with GFP in A. nidulans, it localized to nuclei in phialides. When expressed in the stuA1 mutant, AbaA::GFP localized to nuclei in conidiophores but no longer was confined to phialides, suggesting that expression of AbaA in specific cell types of the conidiophore was conditioned by StuA. Our data suggest that the function in conidiation of StuA and ASM-1 is conserved and support the view that, despite the great morphological and ontogenic diversity of their condiphores, the last common ancestor of A. nidulans and N. crassa produced an ortholog of StuA that was involved in conidiophore development.

Morphotype transition and sexual reproduction are genetically associated in a ubiquitous environmental pathogen

Sexual reproduction in an environmental pathogen helps maximize its lineage fitness to changing environment and the host. For the fungal pathogen Cryptococcus neoformans, sexual reproduction is proposed to have yielded hyper virulent and drug resistant variants. The life cycle of this pathogen commences with mating, followed by the yeast-hypha transition and hyphal growth, and it concludes with fruiting body differentiation and sporulation. How these sequential differentiation events are orchestrated to ensure developmental continuality is enigmatic. Here we revealed the genetic network of the yeast-to-hypha transition in Cryptococcus by analyzing transcriptomes of populations with a homogeneous morphotype generated by an engineered strain. Among this network, we found that a Pumilio-family protein Pum1 and the matricellular signal Cfl1 represent two major parallel circuits directing the yeast-hypha transition. Interestingly, only Pum1 coordinates the sequential morphogenesis events during a-α bisexual and α unisexual reproduction. Pum1 initiates the yeast-to-hypha transition, partially through a novel filament-specific secretory protein Fas1; Pum1 is also required to sustain hyphal growth after the morphological switch. Furthermore, Pum1 directs subsequent differentiation of aerial hyphae into fruiting bodies in both laboratory and clinical isolates. Pum1 exerts its control on sexual reproduction partly through regulating the temporal expression of Dmc1, the meiosis-specific recombinase. Therefore, Pum1 serves a pivotal role in bridging post-mating morphological differentiation events with sexual reproduction in Cryptococcus. Our findings in Cryptococcus illustrate how an environmental pathogen can ensure the completion of its life cycle to safeguard its long-term lineage success.

Afatinib use in non-small cell lung cancer previously sensitive to epidermal growth factor receptor inhibitors: the United Kingdom Named Patient Programme

INTRODUCTION

Afatinib prolongs progression-free survival (PFS) in patients with non-small cell lung cancer (NSCLC) who were previously sensitive to erlotinib or gefitinib. This study investigated experience of afatinib under a Named Patient Use (NPU) programme.

PATIENTS AND METHODS

Retrospective data for 63 patients were collected, including demographics, dose, toxicity and clinical efficacy.

RESULTS

Response rate and median PFS were 14.3% and 2.6months, respectively. Diarrhoea and rash were the most common toxicities; 46% of patients required a dose reduction and 41% had a dose delay.

CONCLUSIONS

Efficacy and safety in the NPU programme are consistent with the LUX-Lung 1 trial.

Congenic strains of the filamentous form of Cryptococcus neoformans for studies of fungal morphogenesis and virulence

Cryptococcus neoformans is an unconventional dimorphic fungus that can grow either as a yeast or in a filamentous form. To facilitate investigation of genetic factors important for its morphogenesis and pathogenicity, congenic a and α strains for a filamentous form were constructed. XL280 (α) was selected as the background strain because of its robust ability to undergo the morphological transition from yeast to the filamentous form. The MATa allele from a sequenced strain JEC20 was introgressed into the XL280 background to generate the congenic a and α pair strains. The resulting congenic strains were then used to test the impact of mating type on virulence. In both the inhalation and the intravenous infection models of murine cryptococcosis, the congenic a and α strains displayed comparable levels of high virulence. The a-α coinfections displayed equivalent virulence to the individual a or α infections in both animal models. Further analyses of the mating type distribution in a-α coinfected mice suggested no influence of a-α interactions on cryptococcal neurotropism, irrespective of the route of inoculation. Furthermore, deletion or overexpression of a known transcription factor, Znf2, in XL280 abolished or enhanced filamentation and biofilm formation, consistent with its established role. Overexpression of Znf2 in XL280 led to attenuation of virulence and a reduced abundance in the brain but not in other organs, suggesting that Znf2 might interfere with cryptococcal neurotropism upon extrapulmonary dissemination. In summary, the congenic strains provide a new resource for the exploration of the relationship in Cryptococcus between cellular morphology and pathogenesis.

Immediate neonatal outcome of adolescent pregnant mother at Nepal Medical College Teaching Hospital

Pregnancy in teenage period of life is often associated with maternal complications as well as preterm delivery, low birth weight babies and small for date babies. The purpose of this study was to know the immediate outcome of neonates delivered by adolescent pregnant mother at Nepal Medical College Teaching Hospital (NMCTH), Attarkhel, Kathmandu. A retrospective comparative study was carried out in 350 adolescent pregnant mother who had delivered newborn at NMCTH from April 2005 to February 2009. Data were obtained from the case record register from Archive. Prevalence of adolescent pregnancy was 11.1%. Majority of adolescent mother were aged between 17-19 years, belonging to Mongolian ethnicity, Hindu by belief and residing within Kathmandu Valley. More than 90.0% mothers were primigravida and 85.4% had complete antenatal check up (ANC). Normal vaginal delivery was the predominant mode of delivery in both group (84.6% vs 80.0%), followed by lower section caesarean section (LSCS) (14.0% vs 18.8%) and instrumental delivery (1.1% Vs 1.2%). In newborn, male outnumbered female (59.7% vs 40.3%). A reasonable number of preterm (10.9% Vs 6.3% p = 0.029), low birth weight (12.3% vs 9.1% P = 0.259) and small for gestational age babies (7.4% vs 5.1% p = 0.318)) and birth asphyxia (10.3% Vs 5.1% p = 0.009%) were found in this study. These newborns are often associated with high morbidity and mortality. Therefore, it is imperative to prevent teenage pregnancy by providing adequate access to health facilities and raising awareness about the sex and reproductive health amongst this population.

Impact of nutrition education on knowledge and haemoglobin status of hill women in Uttarakhand State of India

INTRODUCTION

This study aimed to examine the impact of the use of single vs. combination of media on nutritional knowledge and haemoglobin status of women in a rural hill area in Uttarakhand State, India.

METHODS

Women from three villages were selected randomly and divided into three groups namely, print media group (n = 59), multimedia group (n = 53) and control group (n = 111). The print media group was exposed to nutrition education through the use of calendars on anaemia for 60 days; the multimedia group was given nutrition education through a combination of media including calendars, video films, and group discussions for 60 days.

RESULTS

At pre-exposure stage, 62.7% of the women in the print media group, 67.9% of the multimedia group, and 66.7% of the control group had a low nutrition knowledge level. After exposure, the print media group and the multimedia group showed a significant rise in nutrition knowledge, with the multimedia group scoring significantly higher than the print media group. Overall, 69.1% of the women were anaemic with mean haemoglobin concentration of 10.74 +/- 0.86 g/dl. A non-significant rise in mean haemoglobin concentrations in the experimental groups was found at post-exposure stage.

CONCLUSION

Calendars and video films are effective in increasing nutrition knowledge of illiterate hill women. Use of mass media programmes of longer duration should be encouraged to combat the nutritional problems of rural communities.

Clinical profile of tuberculosis in children

Childhood tuberculosis is common in our community. The diagnosis in most cases is still based on clinical evidence alone. The present study was designed to study clinical profile, laboratory investigations and outcome of pediatric tuberculosis. A prospective study was conducted among the children admitted in Nepal Medical College from April 2007 to March 2011. The prevalence of tuberculosis was 1.5%. Pulmonary tuberculosis was common (53.7%) than extra pulmonary (46.3%) tuberculosis. BCG scar was present in 48.8%. History of tuberculosis contact was present in 36.6% and Mantoux test was positive in 39.0%. The most common symptoms were fever (75.6%), cough (63.4%) and weight loss (41.5%). Confirmed diagnosis was made (bacteriological or histological) only in 14.6%. This study supports the use of history and clinical features to diagnose childhood tuberculosis.

Profile of acute lower respiratory tract infection in children under fourteen years of age at Nepal Medical College Teaching Hospital (NMCTH)

The purpose of this study was to find out the current pattern and prevalence of acute lower respiratory tract infections in children at Nepal Medical College Teaching Hospital in Katmandu, Nepal. A retrospective study was done in 73 children, admitted to the Pediatric ward over a period of one year from January 2010-December 2010. This study showed, 52.0% children below two years of age had acute lower respiratory tract infections, where 68.4% had pneumonia and 31.6% had acute bronchiolitis. The prevalence of infections was 58.9% in male children. The occurrence of infections was common in January and April month. Pneumonia was detected in 37.7% children with malnutrition. The most common presenting symptoms was fever observed in 90.4%, cough in 71.2% and fast breathing in 34.2% children. The WBC count was high in 47.9% children, out of which 43.8% had pneumonia and 4.1% had bronchiolitis. Increased neutrophil count in 36.9% and increased ESR in 50.7% seen in patients only with pneumonia. Chest x-ray showed, lobar pneumonia in 45.2% children where right middle zone was most commonly involved in 42.4% patients. Six (8.2%) children were diagnosed as pulmonary tuberculosis. The average duration of hospital stay was 6 days.

Clinical and bacteriological profile of urinary tract infection in children at Nepal Medical College Teaching Hospital

The aim of this study was to study the clinical and bacteriological profile of urinary tract infection (UTI) in children. This was a prospective study of 40 culture positive cases of UTI in children who attended pediatric outpatient department of Nepal Medical College Teaching Hospital. UTI was more common in female (65.0%) than in male (35.0%). Half were in the age group 1- 5 years. Fever was the most common presentation (65.0%) followed by abdominal pain (42.5%), decreased appetite (37.5%) and dysuria (37.5%). Escherichia coli was the most common (67.5%) bacterial isolate followed by Klebsiella sps (20.0%) and Proteus sps (10.0%). E. coli was 100 % sensitive to nitrofurantoin. E. coli was also highly sensitive to ofloxacin, cefotaxim and amikacin (94.0%). Klebsiella was 100 % sensitive to ciprofloxacin and amikacin. Greater degree of resistance was seen to ampicillin, cotrimoxazole and nalidixic acid.

A role for endocytic recycling in hyphal growth

Actin plays multiple complex roles in cell growth and cell shape. Recently it was demonstrated that actin patches, which represent sites of endocytosis, are present in a sub-apical collar at growing tips of hyphae and germ tubes of filamentous fungi. It is now clear that this zone of endocytosis is necessary for filamentous growth to proceed. In this review evidence for the role of these endocytic sites in hyphal growth is examined. One possibility if that the role of the sub-apical collar is associated with endocytic recycling of polarized material at the hyphal tip. The 'Apical Recycling Model' accounts for this role and predicts the need for a balance between endocytosis and exocytosis at the hyphal tip to control growth and cell shape. Other cell differentiation events, including appressorium formation and Aspergillus conidiophore development may also be explained by this model.

Review of Paediatrics In-Patient at Nepal Medical College and Teaching Hospital

Introduction: This retrospective study was undertaken to analyze the disease pattern in the Pediatric ward in a Medical College. After analyzing the data, our study would emphasize on the prevention and the management modality of the most prevalent diseases in the community. Methodology: This study was carried out retrospectively for one year from January 2008 - December 2008 on the basis of age and sex and the frequency of disease according to the system involved. Results: A total number of 453 patients were admitted during the study period. There were 267(59%) male and 186(41%) female children. Less than five years age group accounted for 180(39.7%) excluding the neonate. In the study period, respiratory tract infections were the commonest cause of admission in all age group 198(43.7%), gastrointestinal including diarrhoeal diseases were 112(24.7%), enteric fever comprised of 22(5%), and other disease comprised of about 143(31.5%) of the total admissions. CNS diseases comprised of 43(9%) of which 7(16%) were meningitis and meningoencephalitis, 26(60%) of the total CNS cases were due to febrile convulsion. Respiratory diseases were found to be the major cause of morbidity in children. Conclusion: Children under five years age being the most common age group amongst all, with infection being the most predominant cause of Pediatric morbidity, the WHO/UNICEF algorithm for Integrated Management of Childhood Illness (IMCI) is specifically suited for the developing country like ours. Key words: Paediatric Inpatient; Morbidity; IMCI DOI: 10.3126/jnps.v31i1.3262J Nep Paedtr Soc 2010;31(1):25-29

Nanoionomer: evaluation of microleakage

BACKGROUND

Glass ionomer cements are widely used in pediatric practice due to their advantage of fluoride release and chemical bond to tooth structure. Adherence of the restorative material to the cavity walls is one of the most important characteristic for it to be proven as an ideal material as it prevents microleakage.

AIMS AND OBJECTIVES

This study was aimed at evaluating the microleakage of nanofilled resin-modified glass ionomer cement compared with the conventional and resin-modified glass ionomer cements.

MATERIALS AND METHODS

Standard class V cavities of size 3 mm x 2 mm x 2 mm were made on a total of 30 extracted teeth and restored with the conventional glass ionomer, resin-modified glass ionomer or nanoionomer. After thermocycling, teeth were immersed in 0.5% methylene blue dye for 24 h. They were then sectioned buccolingually. Microleakage was assessed for the occlusal and gingival walls using a compound microscope by two examiners independently.

RESULTS

Nanoionomer demonstrated the least microleakage, with a mean score of 1.3, compared with the resin-modified glass ionomer (score of 3.2) and conventional glass ionomer cement (score 2.6).

CONCLUSION

Nanoionomer exhibited adequate resistance to microleakage and thus may prove better than conventional or resin-modified glass ionomers.

Perinatal mortality audit

Perinatal mortality rate is a sensitive indicator of quality of care provided to women in pregnancy, at and after child birth and to the newborns in the first week of life. Regular perinatal audit would help in identifying all the factors that play a role in causing perinatal deaths and thus help in appropriate interventions to reduce avoidable perinatal deaths. A retrospective study of perinatal indices was conducted among 816 births delivered during the period of 1 year from April 2007 to March 2008 in Nepal Medical College. There were 11 still births and 11 early neonatal deaths. Breech presentation with stucked head and respiratory distress syndrome in preterm babies are the common causes for perinatal mortality. Within the Wigglesworth's classification; group 1, 3 and 4 are the common groups of perinatal death. The 76.5% of perinatal deaths and 100% of early neonatal deaths were low birth weight babies. Similarly 72.5% of perinatal death and 82% of early neonatal death were preterm babies. The perinatal mortality was 26.9/1000 births, comparable to other studies, but still emphasis should be given to upgrade the neonatal care. The efforts should be made for regular antenatal checkups and improvement of neonatal care.