Retention of Knowledge and Efficacy of a Hands-on Training Session in Oxygen Therapy for COVID-19 among Healthcare Workers.

Introduction: We conducted basic hands-on training in oxygen therapy and ventilatory management of coronavirus disease-2019 (COVID-19) patients to health care workers (HCWs) at our tertiary care hospital. We designed this study aiming to find out the impact of hands-on training in oxygen therapy for COVID-19 patients on the knowledge and degree of retention of this gained knowledge 6 weeks after the training session among HCWs. Materials and methods: The study was conducted after obtaining approval from the Institutional Ethics Committee. A structured questionnaire consisting of 15 multiple-choice questions was given to the individual HCW. This was followed by a structured 1-hour training session on "Oxygen therapy in COVID-19", following which the same questionnaire was given to the HCWs with the questions in a different order. After 6 weeks, the same questionnaire with questions in a different format was sent to the participants as a Google form. Results: A total of 256 responses were obtained for the pre-training test and post-training test. The median [IQR] pre-training test scores and post-training test scores were 8 [7-10] and 12 [10-13], respectively. The median retention score was 11 [9-12]. The retention scores were significantly higher than the pre-test scores. Conclusion: About 89% of the HCWs had a significant gain of knowledge. About 76% of the HCWs were able to retain knowledge, which also means the training program was successful. A definitive improvement in baseline knowledge was observed after 6 weeks of training. We propose conducting reinforcement training after 6 weeks of primary training to further augment retention. How to cite this article: Singh A, Salhotra R, Bajaj M, Saxena AK, Sharma SK, Singh D, et al. Retention of Knowledge and Efficacy of a Hands-on Training Session in Oxygen Therapy for COVID-19 among Healthcare Workers. Indian J Crit Care Med 2023;27(2):127-131.

Sinomenine inhibits amyloid beta-induced astrocyte activation and protects neurons against indirect toxicity.

Amyloid beta is a major constituent of the plaques found in the brains of patients suffering from Alzheimer's disease (AD). A growing body of research work suggests that neuroinflammation plays important roles in the development of AD. Thus, considerable efforts are directed towards identification of compounds that can reduce or inhibit neuroinflammation. Here, we show that sinomenine, a compound present in a Chinese medicinal plant, Sinomenium acutum, inhibits oligomeric amyloid beta-induced production of reactive oxygen species (ROS), nitric oxide (NO) and inflammation-related molecules from astrocytic cells. The conditioned medium from oligomeric amyloid beta-treated astrocytic cells induces cell death in the hippocampal neuronal cells. Importantly, sinomenine inhibits this cell death. In addition, this compound has inhibitory effects on the production of ROS, NO and inflammation-related factors from oligomeric amyloid-beta treated human astrocytes. Finally, the conditioned medium from oligomeric amyloid beta-treated human astrocytes induces cell death in the primary culture of human neurons, which is inhibited by sinomenine. Thus, sinomenine inhibits amyloid beta-induced production of toxic factors from astrocytes, and confers protection to hippocampal neuronal cells as well as human neurons against indirect toxicity. The results suggest that this compound could provide beneficial effects in AD and other neurodegenerative conditions by reducing inflammation and neuronal cell death.

Effects of a Tripeptide on Mitogen-Activated Protein Kinase and Glycogen Synthase Kinase Activation in a Cell Line Derived from the Foetal Hippocampus of a Trisomy 16 Mouse: an Animal Model of Down Syndrome.

Down syndrome (DS) is a developmental disorder that results from the trisomy of chromosome 21. DS patients show several abnormalities including cognitive deficits. Here, we show enhanced activation of the extracellular signal-regulated kinase (ERK), a kinase that critically regulates synaptic plasticity and memory, in a hippocampal cell line derived from trisomy 16 mouse foetus. In addition, these cells show enhanced activation of p38 mitogen-activated protein kinase (p38 MAPK). The hyper-activation of ERK and p38 MAPK is significantly reduced by a small peptide, Gly-Pro-Glu (GPE), derived from insulin-like growth factor-1. In addition, the trisomic cells show reduced level of inhibitory phosphorylation of glycogen synthase kinase-3ß (GSK-3ß), which is enhanced by GPE. Furthermore, the trisomic cells do not show ERK activation in response to KCl depolarization or forskolin treatment. Importantly, ERK activation by these stimuli is observed after GPE treatment of the cells. These results suggest that GPE may help reduce aberrant signalling in the trisomic neurons by affecting MAPK and GSK-3ß activation.

Lar maintains the homeostasis of the hematopoietic organ in Drosophila by regulating insulin signaling in the niche.

Stem cell compartments in metazoa get regulated by systemic factors as well as local stem cell niche-derived factors. However, the mechanisms by which systemic signals integrate with local factors in maintaining tissue homeostasis remain unclear. Employing the Drosophila lymph gland, which harbors differentiated blood cells, and stem-like progenitor cells and their niche, we demonstrate how a systemic signal interacts and harmonizes with local factor/s to achieve cell type-specific tissue homeostasis. Our genetic analyses uncovered a novel function of Lar, a receptor protein tyrosine phosphatase. Niche-specific loss of Lar leads to upregulated insulin signaling, causing increased niche cell proliferation and ectopic progenitor differentiation. Insulin signaling assayed by PI3K activation is downregulated after the second instar larval stage, a time point that coincides with the appearance of Lar in the hematopoietic niche. We further demonstrate that Lar physically associates with InR and serves as a negative regulator for insulin signaling in the Drosophila larval hematopoietic niche. Whether Lar serves as a localized invariable negative regulator of systemic signals such as insulin in other stem cell niches remains to be explored.

Conformation change of α-synuclein(61－95) at the air-water interface and quantitative measurement of the tilt angle of the axis of its α-helix by multiple angle incidence resolution spectroscopy.

Various techniques have been developed to determine protein's structure to understand how proteins work.  Compared with X-ray crystallography requiring proteins to form single crystal structure and NMR which usually needs long time measurement, surface FT-IR techniques are able to quickly determine the tilt angle (the key information to determine whether the α-helix is transmembrane) of peptides/proteins in a monolayer at the interface (e.g. membranes). Specifically, for α-helical peptides/proteins in membrane, the tilt angle of the axis is one of the key information. In this paper, Multiple Angle Incidence Resolution Spectroscopy (MAIRS), a recently developed surface FTIR technique, was applied for the first time to quantitatively determine the tilt angle of the axis of α-helical model peptide related to α-synuclein (α-syn). α-Syn is a 140-amino-acid presynaptic protein whose aggregation is the hallmark of Parkinson's disease (PD). It is difficult for α-syn to form a single crystal structure and the primary structure of α-syn constitutes three domains: the N-terminus containing residues 1-60; the nonamyloid component (NAC) which spans residues 61-95 and is highly prone to aggregation; and C-terminus with residues 96-140. Here, the NAC part (i.e., α-syn(61-95)) responsible for the aggregation was found to change its unstructured conformation in aqueous solution to α-helix at the air-water interface by circular dichroism and MAIRS. In addition, the instinct power of MAIRS to quantitatively measure the tilt angle of the axis of α-helical α-syn(61-95) in monolayer was fully exhibited. Therefore, MAIRS is a potential supplemental technique to X-ray crystallography and NMR to determine the structure of membrane peptides/proteins.

Cell Adhesion-Mediated Actomyosin Assembly Regulates the Activity of Cubitus Interruptus for Hematopoietic Progenitor Maintenance in Drosophila.

The actomyosin network is involved in crucial cellular processes including morphogenesis, cell adhesion, apoptosis, proliferation, differentiation, and collective cell migration in Drosophila, Caenorhabditiselegans, and mammals. Here, we demonstrate that Drosophila larval blood stem-like progenitors require actomyosin activity for their maintenance. Genetic loss of the actomyosin network from progenitors caused a decline in their number. Likewise, the progenitor population increased upon sustained actomyosin activation via phosphorylation by Rho-associated kinase. We show that actomyosin positively regulates larval blood progenitors by controlling the maintenance factor Cubitus interruptus (Ci). Overexpression of the maintenance signal via a constitutively activated construct (ci.HA) failed to sustain Ci-155 in the absence of actomyosin components like Zipper (zip) and Squash (sqh), thus favoring protein kinase A (PKA)-independent regulation of Ci activity. Furthermore, we demonstrate that a change in cortical actomyosin assembly mediated by DE-cadherin modulates Ci activity, thereby determining progenitor status. Thus, loss of cell adhesion and downstream actomyosin activity results in desensitization of the progenitors to Hh signaling, leading to their differentiation. Our data reveal how cell adhesion and the actomyosin network cooperate to influence patterning, morphogenesis, and maintenance of the hematopoietic stem-like progenitor pool in the developing Drosophila hematopoietic organ.

Phacoemulsification Versus Manual Small Incision Cataract Surgery in Patients With Fuchs Heterochromic Iridocyclitis.

PURPOSE: To compare the safety and efficacy of phacoemulsification and manual small incision cataract surgery (SICS) to treat cataract in patients with Fuchs heterochromic iridocyclitis (FHI). DESIGN: A randomized, double-masked, prospective, multicenter study. METHODS: Consecutive patients with cataract after FHI were randomly assigned to have phacoemulsification or manual SICS by 1 of 2 surgeons experienced in both techniques. Complications (intraoperatively and postoperatively), operative time, visual acuities, endothelial cell counts, and surgically induced astigmatism were compared. RESULTS: At 6 months, 65 (92.8%) patients in the phacoemulsification group and 70 (92.1%) in the manual SICS group had a corrected distance visual acuity of 20/63 or better (P = 0.974). Surgical time was significantly shorter in the SICS group (11.2 ± 2.4 minutes) than in the phacoemulsification group (14.2 ± 3.1 minutes) (P < 0.001). The mean surgically induced astigmatism was 0.8 ± 0.2 diopters (D) in the phacoemulsification group and 1.16 ± 0.2 D in the SICS group (P < 0.001). Endothelial cell counts at 1 week and at 6 months did not differ significantly in the phacoemulsification and SICS groups (t test; P = 0.133 and P = 0.032, respectively). Intraoperatively, 2 (3%) eyes randomized to receive phacoemulsification and 4 (5.3%) eyes randomized to receive SICS had posterior capsular rent (P = 0.465). CONCLUSIONS: Both techniques achieved good visual outcomes with low rates of complications. Manual SICS may be a viable alternative for cataract management in patients with FHI in settings with limited access to phacoemulsification.

Phacoemulsification versus small incision cataract surgery in patients with uveitis.

AIM: To compare the safety and efficacy of phacoemulsification and small incision cataract surgery (SICS) in patients with uveitic cataract. METHODS: In a prospective, randomized multi-centric study, consecutive patients with uveitic cataract were randomized to receive phacoemulsification or manual SICS by either of two surgeons well versed with both the techniques. A minimum inflammation free period of 3mo (defined as less than 5 cells per high power field in anterior chamber) was a pre-requisite for eligibility for surgery. Superior scleral tunnel incisions were used for both techniques. Improvement in visual acuity post-operatively was the primary outcome measure and the rate of post-operative complications and surgical time were secondary outcome measures, respectively. Means of groups were compared using t-tests. One way analysis of variance (ANOVA) was used when there were more than two groups. Chi-square tests were used for proportions. Kaplan Meyer survival analysis was done and means for survival time was estimated at 95% confidence interval (CI). A P value of <0.05 was considered statistically significant. RESULTS: One hundred and twenty-six of 139 patients (90.6%) completed the 6-month follow-up. Seven patients were lost in follow up and another six excluded due to either follow-up less than six months (n=1) or inability implant an intraocular lens (IOL) because of insufficient capsular support following posterior capsule rupture (n=5). There was significant improvement in vision after both the procedures (paired t-test; P<0.001). On first postoperative day, uncorrected distance visual acuity (UDVA) was 20/63 or better in 31 (47%) patients in Phaco group and 26 (43.3%) patients in SICS group (P=0.384). The mean surgically induced astigmatism (SIA) was 0.86±0.34 dioptres (D) in the phacoemulsification group and 1.16±0.28 D in SICS group. The difference between the groups was significant (t-test, P=0.002). At 6mo, corrected distance visual acuity (CDVA) was 20/60 or better in 60 (90.9%) patients in Phaco group and 53 (88.3%) in the manual SICS group (P=0.478). The mean surgical time was significantly shorter in the manual SICS group (10.8±2.9 versus 13.2±2.6min) (P<0.001). Oral prednisolone, 1 mg/kg body weight was given 7d prior to surgery, continued post-operatively and tapered according to the inflammatory response over 4-6wk in patients with previously documented macular edema, recurrent uveitis, chronic anterior uveitis and intermediate uveitis. Rate of complications like macular edema (Chi-square, P=0.459), persistent uveitis (Chi-square, P=0.289) and posterior capsule opacification (Chi-square, P=0.474) were comparable between both the groups. CONCLUSION: Manual SICS and phacoemulsification do not differ significantly in complication rates and final CDVA outcomes. However, manual SICS is significantly faster. It may be the preferred technique in settings where surgical volume is high and access to phacoemulsification is limited, such as in eye camps. It may also be the appropriate technique for uveitic cataract under such circumstances.

A randomized controlled trial of peeling and aspiration of Elschnig pearls and neodymium: yttrium-aluminium-garnet laser capsulotomy.

AIM: To compare surgical peeling and aspiration and neodymium yttrium garnet laser capsulotomy for pearl form of posterior capsule opacification (PCO). METHODS: A prospective, randomized, double blind, study was done at Rotary Eye Hospital, Maranda, Palampur, India, Santosh Medical College Hospital, Ghaziabad, India and Laser Eye Clinic, Noida India. Consecutive patients with pearl form of PCO following surgery, phacoemulsification, manual small incision cataract surgery and conventional extracapsular cataract extraction (ECCE) for age related cataract, were randomized to have peeling and aspiration or neodymium yttrium garnet laser capsulotomy. Corrected distance visual acuity (CDVA), intra-operative and post-operative complications were compared. RESULTS: A total of 634 patients participated in the study, and 314 (49.5%) patients were randomized to surgical peeling and aspiration group and 320 (50.5%) to the Nd:YAG laser group. The mean pre-procedural logMAR CDVA in peeling and neodymium: yttrium-aluminium-garnet (Nd:YAG) laser group was 0.80±0.25 and 0.86±0.22, respectively. The mean final CDVA in peeling group (0.22±0.23) was comparable to Nd:YAG group (0.24±0.28; t test, P=0.240). There was a significant improvement in vision after both the procedures (P<0.001). A slightly higher percentage of patients in Nd:YAG laser group (283/88.3%) than in peeling group (262/83.4%) had a CDVA of 0.5 (20/63) or better at 9mo (P<0.001). On the contrary, patients having CDVA worse than 1.00 (20/200) was also significantly higher in Nd:YAG laser group as compared to peeling group (25/7.7% vs 15/4.7%, respectively). On application of ANCOVA, there was less than 0.001% risk that PCO thickness and total laser energy had no effect on rate of complications in Nd:YAG laser group and less than 0.001 % risk that PCO thickness had no effect on complications in peeling group respectively. Sum of square analysis suggests that in the Nd:YAG laser group, thick PCO had a stronger impact on complications (Fischer test probability, Pr<0.0001) than thin PCO and total laser energy (Fischer test probability, Pr<0.002), respectively; similarly, in peeling group, thick PCO and preoperative vision had a stronger effect on complications than thin PCO, respectively (Fischer test probability, Pr<0.001).The rate of complications like uveitis (P=0.527) and cystoid macular edema (P=0.068), did not differ significantly between both the groups. However, intraocular pressure spikes (P=0.046) and retinal detachment (P<0.001) were significantly higher in Nd:YAG laser group as compared to peeling group. Retinal detachment was more common in patients having degenerative myopia (7/87.5%, P<0.001). Recurrence of pearls was the most common cause of reduction of vision in the peeling group (24/7.6%, P<0.001). CONCLUSION: There is no alternative to Nd:YAG laser capsulotomy for fibrous subtype of PCO. For pearl form of PCO, both techniques are comparable with regard to visual outcomes. Nd:YAG laser capsulotomy has a higher incidence of IOP spikes and retinal detachment whereas recurrence of pearls may occur after successful peeling and aspiration. When posterior capsulotomy is needed in patients with retinal degenerations, retinopathies and pre-existing retinal breaks, the clinician should be cautious about increased risks of possible complications of Nd:YAG laser capsulotomy.

Comparison of endothelial cell loss and complications between phacoemulsification and manual small incision cataract surgery (SICS) in uveitic cataract.

INTRODUCTION: Endothelial cell loss and complications after cataract surgery may be higher when cataract is complicated by uveitis. OBJECTIVE: To compare endothelial cell damage and complication rates after phacoemulsification and manual small incision cataract surgery (SICS) in patients with uveitis. MATERIALS AND METHODS: Patients with uveitic cataract were randomly allocated for phacoemulsification (n=75) or manual SICS (n=80) in a double blind prospective study. In the bag implantation of a hydrophobic acrylic intraocular lens was aimed in all cases. Patients with follow up of less than six months were excluded. Main outcome measures were alteration in endothelial cell counts (ECC) and morphology, improvement in vision and complication rates. ECC was measured preoperatively and at 1 week, 3 months and six months, postoperatively. RESULTS: Six patients were lost to follow up and another three due inability to implant IOL. There were no significant difference in endothelial cell counts (P= 0.032), the variance of endothelial cell size (CV) and percentage of hexagonal cells between both the groups at six months (Mann-Whitney test, P=0.283). Endothelial cell density was significantly less in the group in which vitrectomy and/or pupil dilatation procedures were performed (2290±31.5 cells/mm2) versus (2385±50.3 cells/mm2), respectively (t test, P less than0.001). Incidence of postoperative complications that were observed like persistent uveitis (P=0.591), macular edema (P=0.671) and PCO (P=0.678) and visual outcome (P=0.974) were comparable between the two groups. CONCLUSIONS: Manual SICS and phacoemulsification do not differ significantly in endothelial cell loss and complication rates in uveitic eyes. However, increased anterior chamber manoeuvring due to additional procedures may lead to significantly higher endothelial cell loss.

Manual suture less small incision cataract surgery in patients with uveitic cataract.

PURPOSE: The purpose of this study is to evaluate the outcome of manual small incision cataract surgery (SICS) in eyes with uveitic cataract. SETTING: Medical college hospital of the subcontinent. DESIGN: Retrospective case series. MATERIALS AND METHODS: In this retrospective study, patients who underwent SICS with posterior chamber intraocular lens implantation for uveitic cataract from 2006 to 2009 were evaluated. Patients with less than 3 months follow-up were excluded. Post-operative vision and complications were analyzed. RESULTS: A total of 54 patients completed the study. The mean age was 52.3 ± 9.3 years. The mean follow-up was 11.53 ± 5.05 months. The mean surgical time was (10.2 ± 3.8 min). Etiological diagnosis was possible in 31.41% (17/54) of patients. There was a statistically significant improvement in vision after surgery (P < 0.001). When uveitis was well-controlled, pre-operative corticosteroids did not change post-operative inflammation (P = 0.796). However, pre-operative corticosteroids were statistically significantly associated to final best corrected visual acuity (BCVA) (P = 0.010). CONCLUSION: SICS with posterior chamber intraocular lens implantation is safe in most cataracts due to uveitis and improves BCVA at 6 months. Inflammation should be well-controlled pre-operatively for at least 3 months. Posterior capsule opacification, macular edema and persistent uveitis were the main factors affecting visual outcome. SICS requires minimal instrumentation, surgical time is short and can also be performed in rural clinics and eye-camps, where phacoemulsification machines are unavailable. SICS may be a more practical and cost-effective technique for uveitic cataract, in such circumstances.

Development and evaluation of a multiplex polymerase chain reaction for the detection of Mycobacterium tuberculosis from pulmonary specimens.

BACKGROUND: The diagnosis of pulmonary tuberculosis is still a major challenge. Using a polymerase chain reaction (PCR), one can detect Mycobacterium tuberculosis in clinical samples within a few hours. However, single gene targets may result in false negativity due to the absence of target DNA in some M. tuberculosis isolates. The objective of this study was to develop and evaluate a multiplex PCR (M-PCR) using IS6110 and devR primers for the detection of M. tuberculosis in sputum samples. METHODS: Sputum samples were collected from: (1) 200 confirmed cases of tuberculosis; (2) 100 suspected cases of tuberculosis diagnosed on the basis of clinical and radiological findings; (3) 200 non-tubercular patients suffering from respiratory diseases other than tuberculosis, in whom tuberculosis had been excluded. All 500 sputum samples were subjected to PCR using IS6110 primers, and M-PCR using IS6110 and devR primers; results were compared with conventional techniques. RESULTS: It was found that M-PCR was 97.5% successful in detecting the presence of tuberculosis in the confirmed tuberculosis group as compared to 84.5% by IS6110-based PCR. In the suspected tuberculosis group, M-PCR could detect 45% of cases as compared to 40% by IS6110-based PCR. Overall, the specificities of both the PCR and M-PCR were found to be 96.5%. CONCLUSIONS: This study demonstrated that the M-PCR assay is more sensitive than the IS6110-based PCR for the detection of M. tuberculosis in sputum specimens and could be applied in situations of highly suspected tuberculosis when all others tests including IS6110 PCR are negative.

Genetic polymorphisms among Mycobacterium tuberculosis isolates from patients with pulmonary tuberculosis in northern India.

Restriction fragment length polymorphism (RFLP) based on IS6110 is considered the gold standard for Mycobacterium tuberculosis molecular typing. It is useful to discriminate among M. tuberculosis strains, investigate outbreaks and distinguish between reactivation and re-infection. We studied polymorphisms among M. tuberculosis isolates from northern India using RFLP to determine the presence of a correlation between IS6110 based fingerprints and drug resistance and to look for relapse and transmission among patients and their contacts. RFLP patterns of PvuII digested genomic DNA of 100 M. tuberculosis isolates were analyzed using southern blotting with a 245 bp IS6110 probe. Drug sensitivity testing (DST) was conducted for rifampicin (40 microg/ml), isoniazid (1 microg/ml), ethambutol (2 microg/ml) and streptomycin (4 microg/ml) using the proportion method. A high degree of polymorphism was seen among the M. tuberculosis isolates and the number of IS6110 copies varied from 0 to 14, with a predominance of isolates with 11 bands. Seventy-five isolates had a high number of bands, 9 had an intermediate number, 6 isolates had a low number and 10 isolates had no bands. No correlation between IS6110 band numbers and RFLP banding patterns was found with drug resistance or for any particular geographical area, although clustering was seen amongst MDR-TB cases. No cases of relapses or transmissions were seen.

Does multiplex polymerase chain reaction increase the diagnostic percentage in osteoarticular tuberculosis? A prospective evaluation of 80 cases.

PURPOSE: Multiplex Polymerase Chain Reaction (MPCR) is a technique in which two or more gene targets are amplified in a single reaction. This has increased sensitivity of diagnosis as a single gene target may be absent in some Mycobacterium tuberculosis strains. METHODS: MPCR using two target genes specific for Mycobacterium tuberculosis, that is, IS6110 and MPB 64, ZN staining and Mycobacterial culture were performed on synovial fluid/pus samples of 80 (three confirmed, 77 suspected) patients of osteoarticular tuberculosis and 25 non tuberculosis patients. RESULTS: MPCR had a sensitivity of 100% in confirmed cases and 81.8% in clinically suspected cases. AFB was positive in one patient and Mycobacterial culture was positive in three patients. MPCR also had 100% specificity; MPB64 was positive in five patients in which IS6110 was negative whereas IS6110 was positive in two patients in which MPB64 was negative. CONCLUSIONS: MPCR is a sensitive and specific method for diagnosis of paucibacilliary conditions such as osteoarticular tuberculosis.

Activity-dependent acetylation of alpha tubulin in the hippocampus.

Posttranslational modifications in proteins play critical roles in synaptic plasticity and memory. In addition, the enduring form of long-term potentiation (LTP) and long-term memory require synthesis of proteins. Some of the mRNAs are present in the dendrites and are locally translated into proteins. Microtubules play critical roles in neuronal transport including the transport of mRNAs from the cell body to the dendrites. Here, we show that KCl depolarization increases acetylation of α-tubulin, a constituent of microtubules, in the CA1 region of the hippocampal slices. Furthermore, activation of N-methyl-D: -aspartate receptor, a type of glutamate receptor that plays critical roles in LTP and memory, also enhances α-tubulin acetylation. These results show that acetylation of α-tubulin is modulated in an activity-dependent manner.

Tetrahydrocurcumin confers protection against amyloid ß-induced toxicity.

Amyloid plaques and neurofibrillary tangles are the hallmarks of Alzheimer's disease. Amyloid ß, a primary component of the amyloid plaques, is neurotoxic. Considerable attention has been directed toward identifying compounds with neuroprotective properties. Using rat primary hippocampal cultures, we show that tetrahydrocurcumin (THC), a metabolite of curcumin, shows a protective effect against oligomeric amyloid-ß-induced toxicity. We further show that THC reduces amyloid-ß-induced (i) increase in the level of reactive oxygen species, (ii) decrease in mitochondrial membrane potential, and (iii) caspase activation. In addition, we show that THC protects human neurons from oligomeric amyloid-ß-induced toxicity as well. Thus, THC confers protection against amyloid-ß-induced toxicity, and the antioxidant activity may contribute to its protective effect.

Enhanced detection of Mycobacteria stained with rhodamine auramine at 37 degrees C.

Sputum smear microscopy is the most efficient and rapid technique for detection of acid-fast bacilli (AFB). Fluorochrome method of staining is preferred for Mycobacteria in the overburdened laboratories as the fluorescing bacilli are more readily detected than the fuchsin stained bacilli in shorter period of time. A total of 300 sputum samples obtained from suspected cases of Tuberculosis were collected and were subjected to staining by rhodamine auramine at 37 degrees C and also at room temperature (conventional method). The smears were then blindly evaluated. Fifty-eight samples were positive by both methods and 5 were positive at 37 degrees C only. Staining at 37 degrees C increased the smear positivity by 8.6% over conventional staining at room temperature. No smears were positive only with staining at room temperature alone. Out of 58 smears positive by both methods, 25 had equal number of AFB in both smears, 22 had more AFB in smear stained at 37 degrees C and 11 had greater number of AFB in smears stained at room temperature. Our study, therefore, indicates that rhodamine auramine staining at 37 degrees C is superior to conventional auramine method at room temperature for detecting AFB in sputum smears.

Synthesis and Reactions of Calix[4]arene Bisanhydrides(1).

The tetrabenzyl ether, tetra-p-bromobenzenesulfonate, and tetra-p-methylbenzenesulfonate of p-carboxymethylcalix[4]arene in the 1,3-alternate conformation have been converted to the corresponding bisanhydrides. Reactions of the bisanhydrides with alcohols or amines afford calix[4]arenes carrying two carboxymethyl and two carboalkoxymethyl or two amidomethyl groups on the upper rim positions. The substitution pattern that is established confers molecular chirality on the calixarenes.