Molecular docking, dynamics, and quantum chemical study of vanillylacetone and beta-hydroxy ketone derivatives against Mpro of SARS-CoV-2

This study is carried out to find novel active drug candidates which can effectively bind to key residues of main protease (Mpro) of SARS-CoV-2. We performed molecular docking of fifty-seven (57) ligands from two classes: vanillylacetone and its derivatives and beta-hydroxy ketone derivatives against Mpro of SARS-CoV-2. We also docked three antiviral drugs as reference/benchmark drugs including remdesivir (RDV), chloroquine (CQ), and hydroxychloroquine (HCQ) against Mpro for comparison of inhibition tendencies of selected ligands. Binding energies of our reference drugs are as: CQ = -5.1 kcal mol-1 (with predicted inhibition constant (Ki pred) = 177 μmol), HCQ = -5.7 kcal mol-1 (Ki pred = 64.07 μmol) and RDV -6.3 kcal mol-1 (Ki pred = 13.95 μmol). We got remarkable results for our docked ligands as 79% of total ligands indicated binding energies better than CQ, 39 % better than both HCQ and CQ, and 19 % better than all reference drugs. More interestingly interaction analysis of eight best-docked ligands showed that they interacted with desired key residues of Mpro. We further selected the four best-docked ligands L1 = -6.6 kcal mol-1 (Ki pred =13.95 μmol), L6 = -7.0 kcal mol-1 (Ki pred = 7.08 μmol), L34 = -6.0 kcal mol-1 (Ki pred = 38.54 μmol), and L50 = -6.6 kcal mol-1 (Ki pred =13.95 umol) for further analysis by quantum chemical study, molecular dynamic (MD) simulations and ADMET analysis. We have also carried out MD-simulations of six more docked ligand L2, L14, L20, L36, L46 and L48 some of which were showing weak binding affinities and some average binding affinities to check their simulation behavior. Their RMSD, RMSF and binding free energy results were also quite satisfying. We believe the current investigation will evoke the scientific community and highlights the potential of selected compounds for potential use as antiviral compounds against Mpro of SARS-CoV-2.

Enhanced and Fast Face Recognition by Hashing Algorithm

This paper presents a face hashing technique for fast face recognition. The proposed technique employs the two existing algorithms, i.e., 2-D discrete cosine transformation and K-means clustering. The image has to go through different pre-processing phases and the two above-mentioned algorithms must be used in order to obtain the hash value of the face image. The searching process is increased by introducing a modified form of binary search. A new database architecture called Facebases has also been introduced to further speedup the searching process.

Asian earthquake: report from the first volunteer British hospital team in Pakistan

At 8:52 am on 8 October 2005 a massive earthquake wracked northern Pakistan and Kashmir. Various teams were sent to Islamabad and the disaster region from the UK. We discuss the types of injury patterns seen and recommend that a central register of volunteers should be created to deal with similar situations in the future.

Endoscopic retrograde cholangiopancreatography in gallstone-associated acute pancreatitis

BACKGROUND

Early endoscopic retrograde cholangio-pancreatography with or without endoscopic sphincterotomy (ERCP+/-ES) has been advocated to reduce complications in patients presenting with a severe attack of gallstone-associated acute pancreatitis (GAP). However, a recent trial has reported contradictory results. Importantly, patients with acute cholangitis were excluded suggesting it may be a major confounding factor affecting previous studies.

OBJECTIVES

To assess the effectiveness of early ERCP+/-ES compared to conservative management stratified according to severity of disease, concealment of randomisation, acute cholangitis and bilirubin level in the reduction of mortality, morbidity, length of hospitalisation and cost in adults suspected of having GAP.

SEARCH STRATEGY

We searched - Cochrane Library (Issue 4 2003), Medline (1966-2004), EMBASE (1980-2004) and LILACS. 'Grey literature' was sought by looking at cited references and hand searched to identify further relevant trials. Conference proceedings of United European Gastroenterology Week (published in Gut) and Digestive Disease Week (published in Gastroenterology) were also hand searched.

SELECTION CRITERIA

Randomized controlled trials (RCT) of adult patients, from 15 years old or greater, presenting with gallstone-associated acute pancreatitis (GAP) comparing ERCP +/- ES versus Conservative management within 72 hours of admission.

DATA COLLECTION AND ANALYSIS

Data were assessed for quality independently by two reviewers. Wherever appropriate, results were pooled together and sub-grouped by predicted severity of disease. Fixed and random effects models were applied. Sensitivity analysis was performed to test the fragility of results.

MAIN RESULTS

Three trials, involving 511 patients, met inclusion criteria. The test for heterogeneity yielded statistically non-significant results (p-value 0.1 to 0.63) suggesting all comparisons were above the established threshold for combinability (p<0.1). Fixed effect and random effect meta-analyses gave identical results. Early ERCP +/- ES was associated with non-significant effect on reduction of mortality in predicted mild (OR = 0.62, 95% CI = 0.27 to 1.41) and severe GAP (OR = 0.62, 95% CI = 0.27 to 1.41). Reduction in complications was non-significant in predicted mild (OR = 0.89, 95% CI = 0.53 to 1.49), but significant in severe GAP (OR = 0.27, 95% CI = 0.14 to 0.53). There was insufficient evidence to draw any conclusions about hospital stay and cost.

REVIEWERS' CONCLUSIONS

Odds of having complications are reduced in predicted severe disease by early ERCP +/- ES. This effect was however, non-significant in predicted mild disease and for reduction of mortality in either predicted mild or severe disease. These results are controlled for confounding due to associated acute cholangitis and are robust for clinical and statistical heterogeneity.

Recurrent rectal carcinoma treated with high dose rate intraluminal brachytherapy

A 65 years old man with recurrent rectal cancer was treated with remote afterloading High Dose Rate Intraluminal Brachytherapy (HDRILB). After eight weeks of HDRILB there was complete regression of the tumor. Bleeding per rectum and pain in the perineum were greatly improved. He died of myocardial infarction after 41 months of treatment with HDRILB. The treated lesions were incomplete remission at the time of death. The procedure was well tolerated. The only treatment-associated toxicity was grade 2 proctitis, which was treated conservatively. HDRILB can be used as one of the treatment options in patients with recurrent rectal cancers who have undergone previous abdominal surgery and external beam irradiation, as exhibited in our limited experience.

Low-salt bowel cleansing preparation (LoSo Prep) as preparation for colonoscopy: a pilot study

BACKGROUND

Currently available colon cleansing preparations are often poorly tolerated.

AIM

To evaluate the efficacy of a low-volume, low-salt preparation for colonoscopy.

METHODS

This was a pilot study in patients scheduled for colonoscopy. The preparation consisted of 34 g of magnesium citrate and four bisacodyl tablets the day before the procedure, and one bisacodyl suppository on the morning of the procedure.

RESULTS

Twenty patients (age range, 49-81 years; all males) were entered into the study. There were no significant side-effects associated with the preparation. All rated the taste as 'tolerable or better'. The examination was considered to be adequate, with no limitations, in 17 patients (85%), and was scored as good to excellent (no solid stool) in 11 (55%), acceptable (small amounts of solid stool) in six (30%) and poor in three (15%: two in-patients and one out-patient). Importantly, two of the failures then received a standard polyethylene glycol preparation and again failed to show adequate colon preparation.

CONCLUSIONS

This pilot study showed that the low-salt colon cleansing preparation was an effective alternative preparation for colonoscopy.

Expression of inducible nitric oxide synthase contributes to the development of pancreatitis following pancreatic ischaemia and reperfusion

BACKGROUND

Inducible nitric oxide synthase (iNOS) activity is increased in experimentally induced acute pancreatitis. Increased expression of this isoform of nitric oxide synthase has been demonstrated in several organs subjected to ischaemia-reperfusion injury. The present experiment investigated the expression of iNOS and the effect of selective iNOS inhibition in pancreatic ischaemia-reperfusion.

METHODS

Wistar rats (n = 40) were randomly and equally assigned to four groups. Groups 2 and 4 underwent 60 min of total pancreatic ischaemia followed by 6 h of reperfusion (I-R). Groups 1 and 3 underwent sham operation. The selective iNOS inhibitor L-N(6)-(1-iminoethyl)-lysine (L-NIL) was administered to groups 3 and 4. Expression of iNOS was examined by immunohistochemistry. Other investigations included measurement of serum amylase activity and pancreatic wet : dry weight ratio, and histopathological examination.

RESULTS

Eight of ten rats in group 2 (I-R only) expressed iNOS but none of the ten animals in group 1 (sham laparotomy) did so. Group 4 (I-R + L-NIL) animals had significantly lower serum amylase levels and wet : dry weight ratios than those in group 2 (I-R only). Microscopic evidence of pancreatic injury was present only in rats in group 2 (I-R only).

CONCLUSION

Expression of iNOS during reperfusion following pancreatic ischaemia contributes significantly to the development of acute pancreatitis.

Genotypes of Helicobacter pylori obtained from gastric ulcer patients taking or not taking NSAIDs

OBJECTIVE

Whether Helicobacter pylori infection and use of nonsteroidal antiinflammatory drugs (NSAIDs) are independent risk factors for ulcerogenesis remains unclear. We undertook this study to evaluate H. pylori isolates from gastric ulcer patients to determine whether the genotype of the infecting isolate could be correlated with the use or nonuse of NSAIDs.

METHODS

Fifty-two patients presenting with gastric ulcer and infected with H. pylori were included; 26 patients were taking NSAIDs or aspirin (ASA) regularly at the time of ulcer diagnosis. Polymerase chain reaction (PCR) was employed to assess the presence and mosaicism of the following H. pylori genes: cagA, vacA, iceA, and picB.

RESULTS

We found no statistical differences in the presence of these genes in H. pylori isolates from gastric ulcer patients taking or not taking prescription NSAIDs or ASA. A 297-bp fragment of the cagA gene was detected in 96% of the isolates from the NSAID and ASA users and 100% from the non-NSAID users (p = 1.0). A larger and more variable region of the cagA gene was detected more frequently among the isolates from non-NSAID users than those from NSAID users (p = 0.05). Ninety-two percent of the isolates were identified as vacA genotype s1. The dominant vacA subtype was s1b, 76.9% and 65.4% in isolates from non-NSAID-taking or NSAID-taking patients, respectively (p = 0.4). iceA1 genotype was not correlated with gastric ulcer as this allele was only detected in 17.3% of all isolates.

CONCLUSIONS

No significant differences in the presence of the candidate virulence genes vacA, cagA, picB, or iceA were detected in isolates from gastric ulcer patients taking prescription NSAIDs or ASA, compared with those not taking these drugs, indicating that single gene presence does not allow discrimination of isolates that may be important in NSAID-induced ulcerogenesis. A variable region of the cagA gene was more frequently detected in isolates from patients not taking NSAIDs or ASA, suggesting that this gene may be modified by NSAID- or ASA-related factors or that certain strains may be selected for in patients taking these medications.

Houseflies are an unlikely reservoir or vector for Helicobacter pylori

The route of transmission of Helicobacter pylori from individual to individual remains undefined. It has recently been reported that the domestic housefly, Musca domestica, when fed pure cultures of H. pylori, was able to harbor the organism in its midgut for up to 30 h (P. Grubel, S. Hoffman, F. K. Chong, N. A. Barstein, C. Mepani, and D. R. Cave, J. Clin. Microbiol. 35:1300-1303, 1997). Our investigation examined whether houseflies could acquire H. pylori from fresh human feces. Domestic houseflies (40 flies/group) were exposed for 24 h to feces from an H. pylori-positive volunteer, feces from an H. pylori-negative volunteer, or feces from an H. pylori-negative volunteer to which a known amount of viable H. pylori had been added. At various intervals, flies were sacrificed and the midguts were excised, homogenized, and plated in duplicate onto selective horse blood agar plates. All plates were incubated under microaerobic conditions at 37 degreesC for 14 days. Emergent colonies presumptive of H. pylori were picked and tested biochemically to confirm the identity as H. pylori. H. pylori was not recovered from houseflies fed human feces either naturally infected or artificially infected with H. pylori. These results suggest that the domestic housefly is not a vector for transmission or a reservoir for H. pylori infection.

A simple alternative technique of orchiopexy for high undescended testis

Medial displacement of the testicular vessels constitutes an important principle for a successful operation for high undescended testis. Prentiss's manoeuvre involving division of the fascia transversalis attempts to achieve this objective but has not found favour with surgeons because it is more invasive. A simple alternative procedure of rerouting the testicular pedicle behind the fascia transversalis is described. The technique has been reported earlier and this paper aims to illustrate the steps with the help of intraoperative photographs. This method serves as a fixation procedure owing to the 'button-hole' effect of a small pathway and may be combined with other techniques of scrotal fixation such as formation of a dartos pouch and suturing.