Highly sensitive and ultra-rapid antigen-based detection of SARS-CoV-2 using nanomechanical sensor platform.

The rapid spread of COVID-19 including recent emergence of new variants with its extreme range of pathologies create an urgent need to develop a versatile sensor for a rapid, precise, and highly sensitive detection of SARS-CoV-2. Herein, we report a microcantilever-based optical detection of SARS-CoV-2 antigenic proteins in just few minutes with high specificity by employing fluidic-atomic force microscopy (f-AFM) mediated nanomechanical deflection method. The corresponding antibodies against the target antigens were first grafted on the gold-coated microcantilever surface pre-functionalized with EDC-NHS chemistry for a suitable antibody-antigen interaction. Rapid detection of SARS-CoV-2 nucleocapsid (N) and spike (S1) receptor binding domain (RBD) proteins was first demonstrated at a clinically relevant concentration down to 1 ng/mL (33 pM) by real-time monitoring of nanomechanical signal induced by antibody-antigen interaction. More importantly, we further show high specific detection of antigens with nasopharyngeal swab specimens from patients pre-determined with qRT-PCR. The results take less than 5 min (swab to signal ≤5 min) and exhibit high selectivity and analytical sensitivity (LoD: 100 copies/ ml; 0.71 ng/ml of N protein). These findings demonstrate potential for nanomechanical signal transduction towards rapid antigen detection for early screening of SARS-CoV-2 and its related mutants.

A database of annotated tentative orthologs from crop abiotic stress transcripts.

A minimal requirement to initiate a comparative genomics study on plant responses to abiotic stresses is a dataset of orthologous sequences. The availability of a large amount of sequence information, including those derived from stress cDNA libraries allow for the identification of stress related genes and orthologs associated with the stress response. Orthologous sequences serve as tools to explore genes and their relationships across species. For this purpose, ESTs from stress cDNA libraries across 16 crop species including 6 important cereal crops and 10 dicots were systematically collated and subjected to bioinformatics analysis such as clustering, grouping of tentative orthologous sets, identification of protein motifs/patterns in the predicted protein sequence, and annotation with stress conditions, tissue/library source and putative function. All data are available to the scientific community at http://intranet.icrisat.org/gt1/tog/homepage.htm. We believe that the availability of annotated plant abiotic stress ortholog sets will be a valuable resource for researchers studying the biology of environmental stresses in plant systems, molecular evolution and genomics.

Folic acid and phenytoin induced gingival overgrowth--is there a preventive effect.

The role of folic acid (5mg/day) in combination with oral hygiene measures (group II) vis-a-vis oral hygiene measures alone (group I) in prevention of phenytoin-induced gingival overgrowth was investigated in a one-year follow-up study on sixty, 8-13-year-old epileptic children receiving phenytoin. The allocation of the children to the two groups was done alternately. In these children, at baseline, plaque (Silness & Löe), gingivitis (Löe & Silness) and probing depths of gingival sulcus were recorded. These parameters were re-evaluated at 3-monthly intervals when gingival overgrowth was also recorded (Modified Harris & Ewalt Index). It was seen that, after a period of one year, gingival overgrowth occurred in 60 and 50 percent children of groups I & II respectively and its development, too, was delayed in group II. More cases (93 percent) in group II exhibited minimal overgrowth as against 78 percent in group I. The study concluded that systemic folic acid prescribed along with phenytoin delays the onset and reduces the incidence and severity of gingival overgrowth induced by phenytoin.

Incidence of phenytoin induced gingival overgrowth in epileptic children: a six month evaluation.

Thirty children aged 8-13 years with epileptic disorders and receiving mono-drug therapy with Phenytoin, were selected from the Departments of Pediatrics and Neurology of PGIMER, Chandigarh to evaluate the development of gingival overgrowth induced by phenytoin over a period of six months. These children were evaluated at baseline at three monthly intervals for a period of six months for plaque (Silness and Loe, 1964), gingivitis (Loe and Silness, 1963) and probing depth of the gingival sulcus. Gingival overgrowth was noted as and when it developed using modified version of Harris and Ewalt Index, 1942. No attempt was made to modify the childrens' prevailing oral habits. The results indicated that gingival overgrowth in 57% of the children was in the mesio-distal dimension of the gingival papillae and occurred within six months of initiation of therapy with Phenytoin.

In vitro experiment optimization for measuring tetrahydrocannabinol skin permeation.

The purpose of this study was to optimize in vitro experimental conditions for the measurement of Delta(9)-tetrahydrocannabinol (Delta(9)-THC) permeation across human skin using a flow-through diffusion cell system. The drug permeation rates through intact and stripped (stratum corneum (SC) removed) skin were also compared in order to determine if the SC provided significant resistance to the diffusion of hydrophobic Delta(9)-THC. The receiver fluids evaluated were HEPES-buffered Hank's balanced salt solution (HHBSS) with either 4 or 6% bovine serum albumin (BSA), Polyoxyethylene 20 Oleyl Ether (Brij 98) solution (0.5 and 6.0%), and hydroxypropyl-beta-cyclodextrin (HPBCD). The Delta(9)-THC permeability was significantly higher into Brij 98 solutions than into 4% BSA. BSA 6% receiver solutions showed significantly higher Delta(9)-THC permeation over BSA 4%. There were no significant differences in Delta(9)-THC permeability or lag time values between 0.5 and 6% Brij 98 receiver solutions. HPBCD failed to work as a suitable receiver solution. The Delta(9)-THC flux in the stripped skin experiments exceeded the flux in the intact skin experiments. It appears that the SC provides some resistance to the diffusion of Delta(9)-THC across human skin. These experimental results have confirmed the utility of several receiver solutions for the in vitro human skin diffusion study of Delta(9)-THC.

The intraocular pressure and diabetes--a correlative study.

In the present study 60 diabetics were examined for intraocular pressure, scleral rigidity and facility of outflow. The intraocular pressure was found higher than in the general population except in patients with proliferative retinopathy. There was no marked difference in scleral rigidity in diabetics. The facility of outflow was lower in diabetic patients.

Bombesin-like peptides stimulate phosphatidylinositol turnover in rat brain slices.

The ability of bombesin (BN)-like peptides to stimulate phosphatidylinositol turnover in rat brain slices was investigated. BN (1 microM) significantly stimulated inositol-1-phosphate (IP1) but not inositol-4,5-biphosphate (IP2) or inositol-1,4,5-trisphosphate (IP3) production using frontal cortex slices in the presence of LiCl (7.5 mM); BN had no effect on cAMP or cGMP levels. BN and the structurally-related gastrin releasing peptide (GRP) elevated IP1 levels in a dose-dependent manner. Similarly, nanomolar concentrations of the GRP fragment (Ac-GRP20-27) significantly elevated IP1 levels, whereas micromolar concentrations of the inactive GRP1-16 did not. BN significantly elevated IP1 levels in those brain regions enriched in BN receptors such as the olfactory bulb, hippocampus, striatum, thalamus and frontal cortex, whereas IP1 levels were not significantly increased in areas which have a low density of BN receptors such as the cerebellum, medulla/pons and midbrain. These data suggest that CNS BN receptors may utilize phosphatidylinositol as a second messenger.

Prevalence of Ocular Involvement in Leprosy in Easstern Uttar Pradesh.

A survey of 995 cases of leprosy revealed the prevalence of ocular involvement to be 275.4 per thousand. Lepromatous leprosy showed the highest prevalence. Majority of the cases were males, but prevalence of ocular involvement was higher in females. The 40-50 year age group showed the maximum prevalence. The time interval between the onset of skin lesions and the eye lesions, in majority of the cases was 5-10.

Corneal Blindness in Leprosy in Eastern Uttar Pradesh.

One hundred and eighteen cases of leprosy with ocular involvement were found to have corneal involvement out of a total 274 cases of ocular in volvement in leprosy. The common eye lesions observed were chronic conjunctivitis (54.01%), keratitis (47.07%), iritis (31.75%) and lagophthalmos (27.76%). In 38.98% of the cases, the time lag between the onset of skin lesions and corneal lesions was 5 to 15 years. The major causes, which lead to involvement of cornea, were corneal anaesthesia (116), lagophthalmos (76), ectropion (21), entropion (11) and trichiasis (4). Corneal blindness constituted 55.6% of total blindness in leprosy with ocular involvement.

A study of ocular complications in leprosy.

A total of 380 leprosy patients were studied in four different leprosy hospitals. The involvement of eye was found in 18.95% of cases in which 10.97% in lepromatous leprosy and 8.16% in non-lepromatous leprosy cases. In total cases studied 52.63% were of lepromatous leprosy and 47.37% of non lepromatous leprosy cases. Among them 11.05% were males and 18.95% were females. In 72 cases of ocular involvement, males constituted 80.56% and females 19.44% of cases. Maximum cases (52.78%) of ocular involvement were in leprosy patient with 5 to 10 years of duration. Blindness among the total leprosy patients studied was 1.84% which was mainly due to corneal opacity following exposure keratitis and ulceration, iridocyclitis and its complications.