Joint interpretation of AER/FGF and ZPA/SHH over time and space underlies hairy2 expression in the chick limb

Embryo development requires precise orchestration of cell proliferation and differentiation in both time and space. A molecular clock operating through gene expression oscillations was first described in the presomitic mesoderm (PSM) underlying periodic somite formation. Cycles of HES gene expression have been further identified in other progenitor cells, including the chick distal limb mesenchyme, embryonic neural progenitors and both mesenchymal and embryonic stem cells. In the limb, hairy2 is expressed in the distal mesenchyme, adjacent to the FGF source (AER) and along the ZPA-derived SHH gradient, the two major regulators of limb development. Here we report that hairy2 expression depends on joint AER/FGF and ZPA/SHH signaling. FGF plays an instructive role on hairy2, mediated by Erk and Akt pathway activation, while SHH acts by creating a permissive state defined by Gli3-A/Gli3-R>1. Moreover, we show that AER/FGF and ZPA/SHH present distinct temporal and spatial signaling properties in the distal limb mesenchyme: SHH acts at a long-term, long-range on hairy2, while FGF has a shortterm, short-range action. Our work establishes limb hairy2 expression as an output of integrated FGF and SHH signaling in time and space, providing novel clues for understanding the regulatory mechanisms underlying HES oscillations in multiple systems, including embryonic stem cell pluripotency. (C) 2012. Published by The Company of Biologists Ltd.FCT, Portugal [SFRH/BD/33176/2007]; Ciencia2007 Program Contract (Portuguese Government); IBB/CBME, LA; FCT, Portugal (National and FEDER COMPETE Program funds) [PTDC/SAU-OBD/099758/2008, PTDC/SAU-OBD/105111/2008]info:eu-repo/semantics/publishedVersio

Asian Indian College Students: Relationship between Parent–Child Communication Difficulties and Internalization

Children of Asian Indian immigrants in the United States vary in their acculturation from their parents to American culture and society. The U.S.-born second-generation and those who immigrate at an early age may be at risk for emotional and behavioral difficulties. The present study investigated whether certain sociocultural factors related to the negative adjustment of second-generation Asian Indian college students. A survey method measured acculturation, acculturative family distancing, perceived prejudice, and internalization difficulties (i.e., depression, trait anxiety, somatic symptoms, and self-critical perfectionism) of second-generation Asian Indian college students (N = 60), ages 19–25. The sample was primarily Keralite (64.5%) with cultural roots in Southern India, Christian (64.6%), and from the Northeast region of the US. The online survey consisted of Likert-type measures followed by two open-ended questions. College students reported a bicultural mode of acculturation, being adaptive to both mainstream culture and their family’s culture of origin. Parent-child communication difficulties, as reported by the participants, were found to be a significant predictor of internalization problems. Self-critical perfectionism and trait anxiety were the primary problems noted in this particular Asian Indian student sample. The students reported a moderate level of perceived prejudice, which was not related to internalization. From qualitative content analysis, some consistent themes emerged, such as, students’ high academic stress, feelings of inability to meet expectations set for oneself, and the need to protect others and self by not discussing emotional difficulties. Participants, nonetheless, acknowledged exaggerating difficulties more than underreporting them. Recommendations are made for prevention and intervention methods to be used by mental health providers, communities, and schools that have Asian Indian children and youth. Future directions in research and the study’s limitations are addressed

SARS Cov-2 vaccines and vaccination strategies

A rapid change has been undergone in the current pandemic and many countries are being exposed to the third wave of COVID-19. The tireless work for the discovery of vaccine had begun by the time the disease occupied a major part of the globe. This is mainly due to the efficacy of vaccines in preventing diseases and it is one of the cost effective strategies adopted for the prevention of many diseases. Currently a lot of countries have come forth with suitable vaccines to tackle the SARS CoV-2 to some extent. This paper incorporates details about vaccination and the common vaccines in use against COVID-19. Based on the evidences available, keen observations and studies carried out on the previously emerged SARS and MERS, the vaccine against SARS CoV-2 was developed, however the primary focus depend on the spike protein which was considered as a target for the development of suitable immunotherapies and thereby played a potential role in the vaccine development process. Vaccination is the most significant strategy to stop the pandemic and the efficacy of SARS-CoV-2 vaccines provides a genuine gauge of hope for future

GC-MS Analysis of Phytocomponents in Spermacoce articularis L. f. leaf

Spermacoce is a genus of the plant family Rubiaceae. Approximately 280 species distributed in subtropical and tropical regions in Asia and Africa etc. It is commonly known as Nathaisuri in Tamil. Leaf extract of the plant is used in against hemorrhoids, galls tones, jaundice and conjunctivitis. Roots are used to mouthwash to relieve toothache, decoction of the herb used to relieve headache, while seeds are demulcent in diarrhea, dysentery and antimicrobial activity. In vitro and In vivo leaf also contains alkaloids, glycosides, steroids, flavonoids and tannins. Liver diseases are a major public health. A 50% methanolic extract of the leaf were subjected to phytochemical studies and further investigated by GC-MS Analysis

Literary thoughts of H.A. Krishnapillai

In the 16th and 17th centuries A.D., Western Christianity came to Tamil Nadu along with the Western Europeans who came for trade. The Bible was first translated into Indian languages, and it was in Tamil that it was done by Ziegenbalg Iyer. Thus, as the Vedas spread all over the world, the people had a great deal of knowledge of the Scriptures, and since it was the time of European rule, the people had some knowledge of English. Pillai was also proficient in English. Therefore, he has not followed the Tamil tradition as it is, but has also incorporated the life of Europeans into his epic. Correctional Methods By the efforts of Christians, not only the Bible but also other literary texts were translated, so that the people had a wide range of knowledge of language and literature. His works are so good that he is praised as a Christian Kamban and a descendant of Veerama Munivar

Correlation of hemoglobin with creatinine clearance, antioxidant status, lipid peroxidation and ceruloplasmin in patients with chronic kidney disease

Background: Anaemia in CRF is caused primarily by a combination of depressed erythropoiesis and shortened erythrocyte lifespan caused by oxidative stress. Therefore, the present study was designed to investigate the correlation between Hb concentration and antioxidant and lipid peroxidation levels.Methods: The study group consisted of 50 patients with chronic kidney disease who were on conservative treatment with the age group of 20 to 60 years. Based on the creatinine clearance values the patients were assigned in to 3 groups; Stage 3, Stage- 4 and Stage- 5 as per NKF DOQI guidelines. Control group consisted of 50 age and sex matched, non-diabetic, non-smoker healthy volunteers. About 5 ml of blood was collected and serum was used for the estimation of superoxide dismutase, ceruloplasmin and malondialdehyde and haemoglobin level using standard methods. The correlations between the different groups are performed by applying Pearson’s correlation test. The p value of ≤0.05 was taken as the level of significance.Results: A positive correlation of Hb with creatinine clearance (r=0.46, p=0.001), SOD level(r=0.4, p=0.009), serum ceruloplasmin (r=0.3, p=0.07) was observed. Significant positive correlation was found between creatinine clearance and SOD level (r=0.4, p=0.008), ceruloplasmin (r=0.3, p=0.04). A negative correlation was obtained between serum malondialdehyde levels and haemoglobin concentration (r=-0.4, p=0.007) and between creatinine clearance and MDA levels (r=-0.4, p=0.01).Conclusions: The study provides a better understanding of the biochemical parameters underlying anaemia in chronic kidney disease. The increased production of ROS and deficiency of antioxidant enzymes altered the oxidant and antioxidant equilibrium in the plasma of CKD patients

Event--related desynchronization in diffusively coupled oscillator models

We seek explanation for the neurophysiological phenomenon of event related desynchronization (ERD) by using models of diffusively coupled nonlinear oscillators. We demonstrate that when the strength of the event is sufficient, ERD is found to emerge and the accomplishment of a behavioral/functional task is determined by the nature of the desynchronized state. We illustrate the phenomenon for the case of limit cycle and chaotic systems. We numerically demonstrate the occurrence of ERD and provide analytical explanation. We also discuss possible applications of the observed phenomenon in real physical systems other than the brain.Comment: Accepted in Physical Review Letter

To evaluate the hemoglobin concentration, lipid peroxidation and antioxidant status in patients with chronic kidney disease

Background: Oxidative stress plays an important role in the progression of CKD as well as in many of the complications associated with the disease. ROS promotes inflammation, accelerated ageing, fibrosis and apoptosis leading to progression of CKD. Therefore, the present study was carried out to evaluate the serum markers for early diagnosis of patients at different stages of chronic kidney disease.Methods: The study group consisted of 50 patients with chronic kidney disease who were on conservative treatment with the age group of 20 to 60 years. Based on the creatinine clearance values the patients were assigned in to 3 groups; Stage 3, Stage- 4 and Stage- 5 as per NKF DOQI guidelines. Control group consisted of 50 age and sex matched, non-diabetic, nonsmoker healthy volunteers. About 5 ml of blood was collected and serum was used for the estimation of superoxide dismutase, ceruloplasmin and malondialdehyde and haemoglobin level using standard methods. The data was analyzed by applying student’s t test. The p value of ≤0.05 was taken as the level of significance.Results: The haemoglobin concentration in all the 3 CKD stages was found to be significantly decreased (p<0.000) whereas, the serum malondialdehyde (MDA) was significantly increased (p=0.000) in patients with CKD. But serum SOD and ceruloplasmin levels of normal and patients with CKD showed significant decline (p<0.000) only in stage 5 whereas, in stage-2 and stage-3 patients it did not show significant variation.Conclusions: The results of the study reinforce the possibility that antioxidant supplementation may be helpful in correcting anaemia in chronic kidney disease. Treatment of renal anaemia is an effective intervention to ensure better quality of life, to prevent adverse cardiovascular outcomes and to retard the progression of chronic kidney disease so as to reduce the burden of end stage renal disease in the long run

Limb patterning: from signaling gradients to molecular oscillations

The developing forelimb is patterned along the proximal-distal and anterior-posterior axes by opposing gradients of retinoic acid and fibroblast growth factors and by graded sonic hedgehog signaling, respectively. However, how coordinated patterning along both axes is accomplished with temporal precision remains unknown. The limb molecular oscillator hairy2 was recently shown to be a direct readout of the combined signaling activities of retinoic acid, fibroblast growth factor and sonic hedgehog in the limb mesenchyme. Herein, an integrated time-space model is presented to conciliate the progress zone and two-signal models for limb patterning. We propose that the limb clock may allow temporal information to be decoded into positional information when the distance between opposing signaling gradients is no longer sufficient to provide distinct cell fate specification.C.J.S. was supported by Fundacao para a Ciencia e a Tecnologia, Portugal (grant SFRH/BPD/89493/2012); R.P.A. is funded by Ciencia 2007 Program Contract (Portuguese Government) and Programa Operacional Regional do Norte (ON.2) NORTE-07-0124-FEDER-000017. This work was supported by research grants from Institute for Biotechnology and Bioengineering/Centro de Biomedicina Molecular e Estrutural, LA (to I.P.), by the national Portuguese funding through Fundacao para a Ciencia e a Tecnologia (National and FEDER COMPETE Program funds: PTDC/SAU-OBD/099758/2008 and PTDC/SAU-BID/121459/2010 to I.P. and R.P.A., respectively) and by PEst-OE/EQB/LA0023/2011

Chick Hairy1 protein interacts with Sap18, a component of the Sin3/HDAC transcriptional repressor complex

<p>Abstract</p> <p>Background</p> <p>The vertebrate adult axial skeleton, trunk and limb skeletal muscles and dermis of the back all arise from early embryonic structures called somites. Somites are symmetrically positioned flanking the embryo axial structures (neural tube and notochord) and are periodically formed in a anterior-posterior direction from the presomitic mesoderm. The time required to form a somite pair is constant and species-specific. This extraordinary periodicity is proposed to depend on an underlying somitogenesis molecular clock, firstly evidenced by the cyclic expression of the chick <it>hairy1 </it>gene in the unsegmented presomitic mesoderm with a 90 min periodicity, corresponding to the time required to form a somite pair in the chick embryo. The number of <it>hairy1 </it>oscillations at any given moment is proposed to provide the cell with both temporal and positional information along the embryo's anterior-posterior axis. Nevertheless, how this is accomplished and what biological processes are involved is still unknown. Aiming at understanding the molecular events triggered by the somitogenesis clock Hairy1 protein, we have employed the yeast two-hybrid system to identify Hairy1 interaction partners.</p> <p>Results</p> <p>Sap18, an adaptor molecule of the Sin3/HDAC transcriptional repressor complex, was found to interact with the C-terminal portion of the Hairy1 protein in a yeast two-hybrid assay and the Hairy1/Sap18 interaction was independently confirmed by co-immunoprecipitation experiments. We have characterized the expression patterns of both <it>sap18 </it>and <it>sin3a </it>genes during chick embryo development, using <it>in situ </it>hybridization experiments. We found that both <it>sap18 </it>and s<it>in3a </it>expression patterns co-localize <it>in vivo </it>with <it>hairy1 </it>expression domains in chick rostral presomitic mesoderm and caudal region of somites.</p> <p>Conclusion</p> <p>Hairy1 belongs to the hairy-enhancer-of-split family of transcriptional repressor proteins. Our results indicate that during chick somitogenesis Hairy1 may mediate gene transcriptional repression by recruiting the Sin3/HDAC complex, through a direct interaction with the Sap18 adaptor molecule. Moreover, since <it>sap18 </it>and <it>sin3a </it>are not expressed in the PSM territory where <it>hairy1 </it>presents cyclic expression, our study strongly points to different roles for Hairy1 throughout the PSM and in the prospective somite and caudal region of already formed somites.</p