The effect of oral dexamethasone on duration of analgesia after upper limb surgery under infraclavicular brachial plexus block: a randomised controlled trial.

The effects of oral dexamethasone on peripheral nerve blocks have not been investigated. We randomly allocated adults scheduled for forearm or hand surgery to oral placebo (n = 61), dexamethasone 12 mg (n = 61) or dexamethasone 24 mg (n = 57) about 45 min before lateral infraclavicular block. Mean (SD) time until first pain after block were: 841 (327) min; 1171 (318) min; and 1256 (395) min, respectively. Mean (98.3%CI) differences in time until first postoperative pain for dexamethasone 24 mg vs. placebo and vs. dexamethasone 12 mg were: 412 (248-577) min, p < 0.001; and 85 (-78 to 249) min, p = 0.21, respectively. Mean (98.3%CI) difference in time until first postoperative pain for dexamethasone 12 mg vs. placebo was 330 (186-474) min, p < 0.001. Both 24 mg and 12 mg of oral dexamethasone increased the time until first postoperative pain compared with placebo in patients having upper limb surgery under infraclavicular brachial plexus block.

Antibiotic use during pregnancy alters the commensal vaginal microbiota.

Antibiotics may induce alterations in the commensal microbiota of the birth canal in pregnant women. Therefore, we studied the effect of antibiotic administration during pregnancy on commensal vaginal bacterial colonization at gestational week 36. Six hundred and sixty-eight pregnant women from the novel unselected Copenhagen Prospective Studies on Asthma in Childhood (COPSAC2010 ) pregnancy cohort participated in this analysis. Detailed information on oral antibiotic prescriptions during pregnancy filled at the pharmacy was obtained and verified prospectively. Vaginal samples were obtained at pregnancy week 36 and cultured for bacteria. Women who received oral antibiotics during any pregnancy trimester had an increased rate of colonization by Staphylococcus species in the vaginal samples as compared with samples obtained from women without any antibiotic treatment during pregnancy (adjusted OR 1.63, 95% CI 1.06-2.52, p 0.028). Oral antibiotic administration in the third trimester were also associated with increased colonization by Staphylococcus species (adjusted OR 1.98, 95% CI 1.04-3.76, p 0.037). These bacteriological changes were associated with urinary tract infection antibiotics. Women treated in the third trimester of pregnancy were more often colonized by Escherichia coli than women without antibiotic treatment in the third trimester (adjusted OR 1.91, 95% CI 1.04-3.52, p 0.038). This change was associated with respiratory tract infection (RTI) antibiotics. We did not observe any significant changes in vaginal Streptococcus agalactiae (group B streptoccocus) or Staphylococcus aureus colonization following antibiotic treatment in pregnancy. Antibiotic administration during pregnancy leads to alterations in the vaginal microbiological ecology prior to birth, with potential morbidity, and long-term effects on the early microbial colonization of the neonate.

Rhamnogalacturonan acetylesterase elucidates the structure and function of a new family of hydrolases.

BACKGROUND: The complex polysaccharide rhamnogalacturonan constitutes a major part of the hairy region of pectin. It can have different types of carbohydrate sidechains attached to the rhamnose residues in the backbone of alternating rhamnose and galacturonic acid residues; the galacturonic acid residues can be methylated or acetylated. Aspergillus aculeatus produces enzymes that are able to perform a synergistic degradation of rhamnogalacturonan. The deacetylation of the backbone by rhamnogalacturonan acetylesterase (RGAE) is an essential prerequisite for the subsequent action of the enzymes that cleave the glycosidic bonds. RESULTS: The structure of RGAE has been determined at 1.55 A resolution. RGAE folds into an alpha/beta/alpha structure. The active site of RGAE is an open cleft containing a serine-histidine-aspartic acid catalytic triad. The position of the three residues relative to the central parallel beta sheet and the lack of the nucleophilic elbow motif found in structures possessing the alpha/beta hydrolase fold show that RGAE does not belong to the alpha/beta hydrolase family. CONCLUSIONS: Structural and sequence comparisons have revealed that, despite very low sequence similarities, RGAE is related to seven other proteins. They are all members of a new hydrolase family, the SGNH-hydrolase family, which includes the carbohydrate esterase family 12 as a distinct subfamily. The SGNH-hydrolase family is characterised by having four conserved blocks of residues, each with one completely conserved residue; serine, glycine, asparagine and histidine, respectively. Each of the four residues plays a role in the catalytic function.

Crystallization and preliminary X-ray diffraction studies of the heterogeneously glycosylated enzyme rhamnogalacturonan acetylesterase from Aspergillus aculeatus.

Well diffracting crystals of rhamnogalacturonan acetylesterase from Aspergillus aculeatus have been obtained in two polymorphic modifications despite its heterogeneous glycosylation. The best-diffracting crystals (resolution 1.55 A) are orthorhombic. The limit of the diffraction pattern of the other (trigonal) form is 2.5 A. The ability of the enzyme to crystallize appears to depend on the glycosylation of the protein sample. This aspect has been investigated by mass spectrometry, which also showed that the orthorhombic crystals have the same glycosylation as the protein sample used in the crystallization.