Further quantitative in silico analysis of SARS-CoV-2 S-RBD Omicron BA.4, BA.5, BA.2.75, BQ.1, and BQ.1.1 transmissibility

The Covid-19 variants' transmissibility was further quantitatively analyzed in silico to study the binding strength with ACE-2 and find the binding inhibitors. The molecular interaction energy values of their optimized complex structures (MIFS) demonstrated that Omicron BA.4 and 5's MIFS value (344.6 kcal mol^-1) was equivalent to wild-type MIFS (346.1 kcal mol^-1), that of Omicron BQ.1 and BQ. 1.1's MIFS value (309.9 and 364.6 kcal mol^-1). Furthermore, the MIFS value of Omicron BA.2.75 (515.1 kcal mol^-1) was about Delta-plus (511.3 kcal mol^-1). The binding strength of Omicron BA.4, BA. 5, and BQ.1.1 may be neglectable, but that of Omicron BA.2.75 was urging. Furthermore, the 79 medicine candidates were analyzed as the binding inhibitors from binding strength with ACE-2. Only carboxy compounds were repulsed from the ACE-2 binding site indicating that further modification of medical treatment candidates may produce an effective binding inhibitor.

Quantitative in silico analysis of SARS-CoV-2 S-RBD omicron mutant transmissibility

Covid-19 variants transmissibility was quantitatively analyzed in silico to understand the reaction mechanisms and to find the reaction inhibitors. Especially, SARS-CoV-2 omicron mutant (omicron S-RBD) binding affinity with human angiotensin-converting enzyme-2 (ACE-2) was quantitatively analyzed using molecular interaction (MI) energy values (kcal^.mol⁻¹) between the S-RBD and ACE-2. The MI of their optimized complex structures demonstrated that omicron's MI value (749.8) was 1.4 times delta MI (538.1) and 2.7 times alfa MI (276.9). The omicron S-RBD demonstrated the most vital transmissible strength. The 14 currently proposed medical treatment compounds did not show as the inhibitors to block the omicron S-RBD and ACE-2 binding; instead, they adsorbed at the ACE-2 active site and may inhibit the ACE-2 activity. A modified candidate (Gallo catechin gallate) whose two phenolic hydroxy groups were replaced with two carboxy groups was repulsed from ACE-2, indicating that further modification of medical treatment candidates may produce an effective docking inhibitor.

Outcomes of robot-assisted versus conventional laparoscopic low anterior resection in patients with rectal cancer: propensity-matched analysis of the National Clinical Database in Japan

BACKGROUND

Robot-assisted laparoscopic surgery has several advantages over conventional laparoscopy. However, population-based comparative studies for low anterior resection are limited. This article aimed to compare peri-operative results of robot-assisted low anterior resection (RALAR) and laparoscopy.

METHODS

This retrospective cohort study used data from patients treated with RALAR or conventional laparoscopic low anterior resection (CLLAR) between October 2018 and December 2019, as recorded in the Japanese National Clinical Database, a data set registering clinical information, perioperative outcomes, and mortality. Of note, the registry does not include information on the tumour location (centimetres from the anal verge) and diverting stoma creation. Perioperative outcomes, including rate of conversion to open surgery, were compared between RALAR and CLLAR groups. Confounding factors were adjusted for using propensity score matching.

RESULTS

Of 21 415 patients treated during the study interval, 20 220 were reviewed. Two homogeneous groups of 2843 patients were created by propensity score matching. The conversion rate to open surgery was significantly lower in the RALAR group than in the CLLAR group (0.7 versus 2.0 per cent; P < 0.001). The RALAR group had a longer operating time (median: 352 versus 283 min; P < 0.001), less intraoperative blood loss (15 versus 20 ml; P < 0.001), a lower in-hospital mortality rate (0.1 versus 0.5 per cent; P = 0.007), and a shorter postoperative hospital stay (median: 13 versus 14 days; P < 0.001) compared with the CLLAR group. The CLLAR group had a lower rate of readmission within 30 days (2.4 versus 3.3 per cent; P = 0.045).

CONCLUSION

These data highlight the reduced conversion rate, in-hospital mortality rate, intraoperative blood loss, and length of postoperative hospital stay for rectal cancer surgery in patients treated using robot-assisted laparoscopic surgery compared with laparoscopic low anterior resection.

Disease-modifying effects of COX-2 selective inhibitors and non-selective NSAIDs in osteoarthritis: a systematic review

Osteoarthritis (OA) is a potentially disabling disease whose progression is dependent on several risk factors. OA management usually involves the use of non-steroidal anti-inflammatory drugs (NSAIDs) that are the primary pharmacological treatments of choice. However, NSAIDs have often been associated with unwanted side effects. Cyclooxygenase (COX)-2 specific inhibitors, such as celecoxib, have been successfully used as an alternative in the past for OA treatment and have demonstrated fewer side effects. While abundant data are available for the clinical efficacy of drugs used for OA treatment, little is known about the disease-modifying effects of these agents. A previous review published by Zweers et al. (2010) assessed the available literature between 1990 and 2010 on the disease-modifying effects of celecoxib. In the present review, we aimed to update the existing evidence and identify evolving concepts relating to the disease-modifying effects of not just celecoxib, but also other NSAIDs. We conducted a review of the literature published from 2010 to 2016 dealing with the effects, especially disease-modifying effects, of NSAIDs on cartilage, synovium, and bone in OA patients. Our results show that celecoxib was the most commonly used drug in papers that presented data on disease-modifying effects of NSAIDs. Further, these effects appeared to be mediated through the regulation of prostaglandins, cytokines, and direct changes to tissues. Additional studies should be carried out to assess the disease-modifying properties of NSAIDs in greater detail.

Quantitative In Silico Analysis of Retention of Nitrobenzofurazan-Amino Acids in Reversed-Phase Ion-Pair Liquid Chromatography

The retention mechanisms of nitrobenzofurazan (NBD)-amino acids in reversed-phase ion-pair liquid chromatography were quantitatively analyzed in silico The most contributed interaction for the retention is the Lewis acid-base interaction between an aromatic ring of NBD-amino acids and hydroxyl-group hydrogen of tetra-butyl-ammonium hydroxide coated on the hydrophobic phase. Solvent effects significantly improved the relation between the calculated molecular interaction (MI) energy values using a molecular mechanics program and log k values measured in chromatography. The correlation coefficient between the calculated MI energy values and the log k values was >0.95.

Quantitative In Silico Analysis of Retention of Phenylthiohydantoin-Amino Acids in Reversed-Phase Ion-Pair Liquid Chromatography

The retention mechanisms of phenylthiohydantoin (PTH)-amino acids in reversed-phase ion-pair liquid chromatography were quantitatively analyzed in silico. The most significant interaction for the retention was the Lewis acid-base interaction between an aromatic ring of a PTH-amino acid and a hydroxyl-group hydrogen of tetra-alkyl ammonium hydroxide. Solvent effects, addition of molecular interaction (MI) energy values between an analyte and solvent molecules, significantly improved the relationship between the MI energy values, calculated using a molecular mechanics program, and logk values, measured via chromatography. The correlation coefficient between the calculated MI energy values and the logk values was 0.98 (n = 19).

The long-term outcome of transvaginal anterior levatorplasty for intractable rectovaginal fistula

AIM

Several procedures have been described for rectovaginal fistula with a wide range of success, but there is little information on the long-term outcome. The aim of the present study was to investigate the long-term outcome after transvaginal anterior levatorplasty (ALP) for intractable rectovaginal fistula.

METHOD

Data of 16 consecutive patients undergoing transvaginal ALP with fistulectomy and closure of the rectum and vagina between 1998 and 2011 were prospectively recorded and retrospectively investigated to study the long-term outcome.

RESULTS

Birth injury (n = 7), low anterior resection for rectal cancer (n = 3), pouch surgery for ulcerative colitis (n = 2) and a procedure for prolapse and haemorrhoids (n = 2) were the main causes of the fistula. Nine patients had a covering stoma before surgery. All patients underwent ALP, with a covering stoma in two patients. Infection occurred in one patient and wound rupture after surgery in another patient. These patients underwent reoperation by ALP. All fistulae had healed at a median follow-up of 84 (8-193) months after initial surgery or stoma closure.

CONCLUSION

Transvaginal ALP is effective for the treatment of mid or low rectovaginal fistula. The results show that a graft is not necessary regardless of whether or not previous surgery has been performed.

RSC Chromatography Monographs Quantitative In Silico Chromatography Computational Modelling of Molecular Interactions

All early chromatographic techniques, starting from the primitive "ancient" chromatography introduced by Tswett in the very early twentieth century, perfected in partition chromatography in the 1940s by Martin and Synge, and extended to a variety of additional separation mechanisms later, were first entirely experimental trial-and-error methods. The early years can also be characterized by searching for theoretical base of various separation techniques that would allow establishing relation between the structure of the analytes and their chromatographic behavior. The advent of computers followed by development of the new software then revolutionized the theoretical approaches and enabled detailed modeling instead of tedious experimentation. This book introduces the readers to the era of computational modeling in which molecular interactions are used to analyze the mechanisms of general molecular interactions with a special focus on biological applications. This article is protected by copyright. All rights reserved.

Transvaginal anterior levatorplasty with posterior colporrhaphy for symptomatic rectocele

BACKGROUND

We evaluated functional and morphological outcomes of transvaginal anterior levatorplasty with posterior colporrhaphy for symptomatic rectocele.

METHODS

Ten women (median 68 years) underwent transvaginal anterior levatorplasty with posterior colporrhaphy for symptomatic rectocele. Symptoms and continence were monitored before and after surgery. Manovolumetric study and defecography were performed in 9 of 10 patients before and 3-6 months after surgery. Twenty-one females without anorectal diseases were used as controls in manovolumetric study. The patients were followed up after a median of 89 months (range, 3-103).

RESULTS

Main symptoms (defecatory disorders in 9 patients, vaginal mass in 6, perineal discomfort in 2) disappeared after surgery. Six patients performed digitation preoperatively and gave up digitation on defecation after surgery. Stool incontinence disappeared in 4 of 5 preoperatively incontinent patients (Cleveland clinic score, 5-12) and continence score improved from 5 to 2 in the remaining patient. Three patients with urinary cough incontinence preoperatively did not experience incontinence after surgery but cough incontinence occurred occasionally in an 81-year-old patient postoperatively. Rectocele demonstrated on defecography disappeared postoperatively in all 9 patients who underwent defecography. High threshold volume and maximum tolerable volume, which were observed preoperatively, decreased to control levels after surgery.

CONCLUSION

Transvaginal anterior levatorplasty with posterior colporrhaphy might be an option for symptomatic rectocele to improve anorectal and urinary dysfunctions with morphological disorders.

Response of parathyroid hormone to exercise and bone mineral density in adolescent female athletes

BACKGROUND

This study investigates 1) the effects of amount of exercise on levels of serum parathyroid hormone (PTH) and calcium, and 2) the relationship between PTH response and bone mineral density in adolescent female athletes.

SUBJECTS

Twenty-one female athletes on a top-ranked high school basketball team in Japan participated in a one-month intensive basketball program. Subjects were divided into moderate-exercise and strenuous-exercise groups.

METHODS

The amount of exercise was quantified using estimated metabolic equivalent (METs) and exercise hours. Levels of serum intact-PTH and calcium were examined five times: twice before training to establish a baseline (T(-1) and T(0)), once 3rd week of the training period (T(1), once immediately at the end of the program (T(2)), and again one week later(3)). Bone mineral density of forearm (distal-BMD) was measured one week after the end of the program. PTH levels at T(1), T(2) and(3) were regressed on PTH at baseline (T(0)) for both groups and examined for statistical significance. Multiple regression analyses of the changes of PTH and distal-BMD were conducted.

RESULTS

1) Strenuous-exercise subjects showed both increased and decreased PTH levels, while moderate-exercise subjects showed a uniform decrease in PTH throughout the exercise period. 2) Increased PTH was an independent negative predictor of distal-BMD, while high lean body mass, increased serum Ca, and exercise volume were positive predictors.

CONCLUSION

The amount of exercise affects PTH response: moderate exercise suppresses PTH secretion, while strenuous exercise is apt to induce continuous secretion, which has a negative effect on BMD.

Role of the active site residues arginine-216 and arginine-237 in the substrate specificity of mammalian D-aspartate oxidase

D-aspartate oxidase (DDO) and D-amino acid oxidase (DAO) are flavin adenine dinucleotide-containing flavoproteins that catalyze the oxidative deamination of D-amino acids. Unlike DAO, which acts on several neutral and basic D-amino acids, DDO is highly specific for acidic D-amino acids. Based on molecular modeling and simulated annealing docking analyses, a recombinant mouse DDO carrying two substitutions (Arg-216 to Leu and Arg-237 to Tyr) was generated (R216L-R237Y variant). This variant and two previously constructed single-point mutants of mouse DDO (R216L and R237Y variants) were characterized to investigate the role of Arg-216 and Arg-237 in the substrate specificity of mouse DDO. The R216L-R237Y and R216L variants acquired a broad specificity for several neutral and basic D-amino acids, and showed a considerable decrease in activity against acidic D-amino acids. The R237Y variant, however, did not show any additional specificity for neutral or basic D-amino acids and its activity against acidic D-amino acids was greatly reduced. The kinetic properties of these variants indicated that the Arg-216 residue is important for the catalytic activity and substrate specificity of mouse DDO. However, Arg-237 is, apparently, only marginally involved in substrate recognition, but is important for catalytic activity. Notably, the substrate specificity of the R216L-R237Y variant differed significantly from that of the R216L variant, suggesting that Arg-237 has subsidiary effects on substrate specificity. Additional experiments using several DDO and DAO inhibitors also suggested the involvement of Arg-216 in the substrate specificity and catalytic activity of mouse DDO and that Arg-237 is possibly involved in substrate recognition by this enzyme. Collectively, these results indicate that Arg-216 and Arg-237 play crucial and subsidiary role(s), respectively, in the substrate specificity of mouse DDO.

Effect of edaravone on ischemia/reperfusion injury in rat urinary bladder--changes in smooth muscle cell phenotype and contractile function

Edaravone is a newly developed radical scavenging agent that has been widely used for protection against ischemia/reperfusion (I/R) injury in patients with cerebral infarction. The present study investigated the effects of edaravone on the I/R injury in rat urinary bladder. Adult male rats were divided in the four groups: groups 1-3 received 1 hour of ischemia followed by 1 hour of reperfusion with saline and with edaravone (1 and 3 mg/kg body weight), and group 4 were age-matched control rats. The in vivo ischemia was created by clamping the vesical arteries for 1 hour and reperfusion was accomplished by removing the clips and lasted for 1 hour. Edaravone or saline were administered after reperfusion for 30 min. Following reperfusion, the bladder was excised and separated. Bladder smooth muscle cell (SMC) phenotypic expression was investigated in the electron microscope. The number of contractile and non-contractile bladder SMC phenotype according to the morphological criteria was counted and the ratio of non-contractile to contractile phenotype was calculated. The responses to electrical field stimulation and carbachol were recorded. Edaravone administration resulted in the protection of the morphological changes and contractile responses to both EFS and carbachol that were affected by the agent. Our findings demonstrate that edaravone has a potentially protective effect on I/R-induced damage in the rat bladder.

Hyperactive mutants of mouse D-aspartate oxidase: mutagenesis of the active site residue serine 308

The role of Ser-308 of murine D-aspartate oxidase (mDASPO), particularly its side chain hydroxyl group, was investigated through the use of site-specific mutational analysis of Ser-308. Recombinant mDASPO carrying a substitution of Gly, Ala, or Tyr for Ser-308 was generated, and fused to either His (His-mDASPO), or glutathione S-transferase, His, and S (GHS-mDASPO) at its N-terminus. Wild-type His-mDASPO or GHS-mDASPO or their mutant derivatives were expressed in Escherichia coli and purified by affinity chromatography. All purified recombinant proteins had functional DASPO activity. The Gly-308 and Ala-308 mutants had significantly higher catalytic efficiency towards D-Asp and N-methyl-D-Asp, and a higher affinity for flavin adenine dinucleotide (FAD) compared to the wild-type enzyme. The Tyr-308 mutant had lower catalytic efficiency and binding capacity. These results suggest that the side chain hydroxyl group of a critical residue of mDASPO, Ser-308, down-regulates enzymatic activity, substrate binding, and FAD binding. This study provides information on the active site of DASPO that will considerably enhance our understanding of the biological significance of this enzyme.

Retention behaviour of polyunsaturated fatty acid methyl esters on porous graphitic carbon

Retention with porous graphitic carbon was investigated with 25 structures of fatty acid methyl esters (FAMEs) with two different mobile phases: CH(3)CN:CHCl(3) 60:40 (v/v) and CH(3)OH:CHCl(3) 60:40 (v/v) with both 0.1% triethylamine (TEA) and an equimolar amount of HCOOH. Preliminary results showed that the use of TEA/HCOOH led to the response increase of saturated FAMEs with evaporative light scattering detection. No increase was observed for unsaturated one. These modifiers may slightly reduce the retention of FAMEs but did not significantly modify the separation factor with porous graphitic carbon. Thermodynamic parameters were calculated for each structure using Van't Hoff plot measured over the temperature range from 10 to 50 degrees C, with the both mobile phase conditions. All the studied compounds were found linked by the same retention mechanism on porous graphitic carbon. Quantitative in silico analysis of the retention using a molecular mechanics calculation demonstrated a good correlation between the retention factors and the molecular interaction energy values (r>0.93). Especially the Van der Waals energy was predominant, and the contribution of electrostatic energy was negligible for the quantitative analysis of the retention. The results indicate that Van der Waals force, hydrophobic interaction, is predominant for the retention of FAMEs on this packing material. The relative retention for highly unsaturated homologues can be changed by the selection of the weak solvent CH(3)CN or CH(3)OH. Then isomers differing only in the position of the carbon double bond on the alkyl chain can be separated and their behaviour is summarised as the closer the carbon double bonds to the FAME polar head, the more the retention decreases. Finally, the more important the number of carbon double bonds in the alkyl chain is, the smaller the retention is.

Creatol, an oxidative product of creatinine in kidney transplant patients, as a useful determinant of renal function: a preliminary study

Creatol (CTL, 5-hydroxycreatinine) is a creatinine (Cr) oxidative metabolite, which was originally isolated from the urine of patients with chronic renal failure, representing a candidate for a uremic toxin. The effectiveness of CTL as an indicator of oxidative stress after kidney transplantation has not been reported. Therefore, we examined the relation between the change in oxidative stress (using CTL) in renal transplant patients and their change in renal function (using Cr). The serum Cr and serum and urine CTL were examined in five renal transplant patients. Serum CTL closely correlated with serum Cr. Serum CTL also correlated with urine CTL, but in some cases there was a time lag. Both the ratio of CTL/(Cr) and serum CTL observed in patient 2 were slow to improve after transplantation. The process through which oxidative stress was reduced was shown by the index of renal damage correlated with kidney function oxidative stress (using serum CTL) after transplantation. Our data suggested that CTL/Cr may be a good indicator of graft prognosis.