Feedbacks from the metabolic network to the genetic network reveal regulatory modules in E. coli and B. subtilis

The genetic regulatory network (GRN) plays a key role in controlling the response of the cell to changes in the environment. Although the structure of GRNs has been the subject of many studies, their large scale structure in the light of feedbacks from the metabolic network (MN) has received relatively little attention. Here we study the causal structure of the GRNs, namely the chain of influence of one component on the other, taking into account feedback from the MN. First we consider the GRNs of E. coli and B. subtilis without feedback from MN and illustrate their causal structure. Next we augment the GRNs with feedback from their respective MNs by including (a) links from genes coding for enzymes to metabolites produced or consumed in reactions catalyzed by those enzymes and (b) links from metabolites to genes coding for transcription factors whose transcriptional activity the metabolites alter by binding to them. We find that the inclusion of feedback from MN into GRN significantly affects its causal structure, in particular the number of levels and relative positions of nodes in the hierarchy, and the number and size of the strongly connected components (SCCs). We then study the functional significance of the SCCs. For this we identify condition specific feedbacks from the MN into the GRN by retaining only those enzymes that are essential for growth in specific environmental conditions simulated via the technique of flux balance analysis (FBA). We find that the SCCs of the GRN augmented by these feedbacks can be ascribed specific functional roles in the organism. Our algorithmic approach thus reveals relatively autonomous subsystems with specific functionality, or regulatory modules in the organism. This automated approach could be useful in identifying biologically relevant modules in other organisms for which network data is available, but whose biology is less well studied.Comment: 15 figure

Clinical profile and histo-pathological profile of peri-ocular lesions

Background: Eyelid carcinoma is the most common malignant lesion of eyelid region, and may involve either skin or tarus or inner layer of eyelid. The most common primary eyelid malignancy is basal cell carcinoma (BCC), squamous cell carcinoma (SqCC), sebaceous gland carcinoma (SGC), malignant melanoma, and Merkel cell carcinoma. The prevalence of these malignant lesion vary according to the geographical region. The aim of the study was to correlate the diagnosis of various peri-ocular lesions with the histological diagnosis.Methods: This prospective longitudinal study was conducted over a period of two years in patients with ocular and periocular skin lesions. All the patients underwent incision biopsy of the lesion biopsy material was sent for histopathology examination. The histological profile of the tumour was confirmed by the report.Results: The mean age in our study was 32.7±18.4 years with age range of 18 to 78 years, with 108 females (54%) and 92 males (46%). 173 (86.5%) were benign lesions and 27 (13.5%) were malignant lesions. Right eye was involved in more cases (n=104, 52%) as compared to left eye (n=96, 48%). Upper eye lid was involved more (n=102, 51%) than lower eye lid (n=98, 49%). Epidermal cyst was most common lesion (n=43, 21.5%), followed by dermoid cyst (n=28, 14%). Sebaceous gland carcinoma was most (n=15, 7.5%) malignant lesion, followed by basal cell carcinoma (n=7, 3, 5%).Conclusions: All excised eyelid lesions must be submitted for histopathologic confirmation to achieve 100% accuracy in diagnosis and treatment. Early diagnosis remains essential for adequate functional and cosmetic lid reconstruction

Practical stability and boundedness criteria of impulsive differential system with initial time difference

In this paper, an impulsive differential system is investigated for the first time for practical stability and boundedness criteria with respect to initial time difference. The investigations are carried out by perturbing Lyapunov functions and by using comparison results. A generalized Lyapunov function has been used for the investigation. The present results indicate that the stability criteria significantly depend on the moment of impulses.Publisher's Versio

Cardiovascular abnormalities in severe scrub typhus

Background: Himachal Pradesh is an endemic area for scrub typhus. If not treated early, it can lead to life threatening complications, affecting various systems of the body. Hence, this study was done with an objective to study the cardiovascular abnormalities in patients of severe scrub typhus.Methods: Authors conducted a hospital-based study in Departments of Medicine and Cardiology, of a tertiary care hospital in Sub-himalayan region in patients of severe scrub typhus from June 2016 to May 2017.Results: Thirty-two (55%) patients were aged <60 years with female preponderance (72%).   Electrocardiographic changes included sinus tachycardia in 56 (97%), axis deviation in 5(9%), ST-T changes in 3(5%) and atrial fibrillation in 1(2%). Echocardiographic changes included tricuspid regurgitation in 14(24%), pericardial effusion in 4(7%), myocarditis in 1(2%) and Regional wall motion abnormality in 1(2%). Left ventricular ejection fraction >45% in 47 (81%) and <45% in 11(19%).  Fifty-one patients had hypotension at presentation and 49 (90%) of them improved. Interestingly, 10 of 11 patients with reduced EF (<45%) survived whereas 6 of total 7 patients, who died, had preserved EF (>45 %).Conclusions: Severe scrub typhus manifested with ST/T changes, myocarditis, pericardial effusion, arrhythmias, shock and patients with reduced EF on Echocardiography had better outcome

Clinical profile of scrub typhus patients in a tertiary care centre in Himachal Pradesh, India

Background: Scrub typhus a zoonotic disease caused by gram negative bacteria O. tsutsugamushi, is endemic in Himachal Pradesh. This illness occurs mainly in monsoon and post monsoon season. study design of  this study was conducted in a tertiary care centre in Himachal Pradesh between July 2015 and June 2016. All the indoor patients with age above 18 years with a diagnosis of scrub typhus were included in this study.Results: Out of total 180 patients, 130 were female patients. Most patients were in the age group 21-30 (23.3%). All the patients presented with history of fever, but 54 patients presented with high grade fever. Other Most common symptom was chills and rigours (81%), followed by vomiting and headache each 32%, cough 31%. On examination 21% patients had eschar,14% patients had lymphadenopathy. Most number of patients presented in the month of September (51.6%), followed by August (33.3%).Conclusion: Scrub typhus being an important differential of acute undifferentiated fever in this region, should not be missed by primary care physicians, as once multi organ dysfunction sets in, mortality rate starts rising. So, there is a high need of sensitization of doctors and people about this illness so that early diagnosis and early treatment can be ensured

Prevalence of refractive errors and their association with socio demographic characteristics in pediatric patients attending tertiary eye care centre

Background: Uncorrected refractive errors are one of the major culprits of visual impairment among children in our country. Children included in school going age groups i.e., 6-16 years, represent 25% of population in developing countries. They fall in the category of preventable age group for correction of refractive errors. This paper describes the salient features and results of the cross-sectional study conducted to determine the prevalence of refractive errors and their association with socio demographic characteristics in pediatric population objective were to study the prevalence of refractive errors and their association with socio demographic characteristics in pediatric patients attending tertiary eye care centre.Methods: The cross-sectional study was conducted for a period of one year among children in 0-16 years age group and a total of 444 patients were included. All children were examined by ophthalmologists and refraction was done by optometrists. Data was analysed using web-based software open epi version 3.01.Results: Prevalence of refractive errors was found to be 29.5%. Amongst the socio demographic factors, there was a significant association of age and literacy with refractive errors whereas gender and residence were not found to be significant.Conclusions: Refractive errors are an important preventable cause of childhood ocular morbidity. Schools are an excellent platform to educate children and their parents regarding eye care and signs of ocular morbidity due to refractive errors. Health education activities in schools need to be intensified

Post craniectomy paradoxical brain herniation: a case report with radiological review

Sinking skin flap (SSF) syndrome and paradoxical brain herniation are rare complications after craniectomy. On CT scan, there is shrunken appearance of the skin flap at craniectomy site. The meningogaleal complex is drawn inwards and is resting on underlying deformed brain with resultant concave surface. It results due to altered CSF hydrodynamics. Paradoxical brain herniation is rare complications which occur in patients who undergo cerebrospinal fluid (CSF) drainage procedures like lumbar puncture (LP), external ventricular drainage, ventriculo-peritoneal shunting and post craniectomy. Its early detection on imaging is essential as it is a neurosurgical emergency. We report a case of 75 year old male previously operated for left chronic subdural hematoma in the left fronto-temporo-parietal region presenting with altered consciousness and inability to walk. Plain CT scan showed craniectomy defect in the left fronto-temporo-parietal region with indrawing of meningogaleal complex suggestive of Shrunken Skin Flap. There was mass effect on the left lateral ventricle and third ventricle with shift of the midline structures towards right (1cm) with evidence of subfalcine herniation suggestive of paradoxical brain herniation

Comparison of capillary based microflurometric assay for CD4+ T cell count estimation with dual platform Flow cytometry

The CD4+ T cell count estimation is an important monitoring tool for HIV disease progression and efficacy of anti-retroviral treatment (ART). Due to availability of ART at low cost in developing countries, quest for reliable cost effective alternative methods for CD4+ T cell count estimation has gained importance. A simple capillary-based microflurometric assay (EasyCD4 System, Guava Technology) was compared with the conventional flow cytometric assay for estimation of CD4+ T cell counts in 79 HIV infected individuals. CD4+ T cell count estimation by both the assays showed strong correlation (r = 0.938, p < 0.001, 95% CI 0.90 to 0.96). The Bland Altman plot analysis showed that the limits of variation were within agreeable limits of ± 2SD (-161 to 129 cells/mm(3)). The Easy CD4 assay showed 100% sensitivity for estimating the CD4+ T cell counts < 200 cells/mm(3 )and < 350 cells/mm(3 )and 97% sensitivity to estimate CD4+ T cell count < 500 cells/mm(3). The specificity ranged from 82 to 100%. The Kappa factor ranged from 0.735 for the CD4+ T cell counts < 350 cells/mm(3 )to 0.771 for < 500 cells/mm(3 )CD4+ T cell counts. The system works with a simple protocol, is easy to maintain and has low running cost. The system is compact and generates minimum amount of waste. Hence the EasyCD4 System could be applied for estimation of CD4+ T cell counts in resource poor settings