The abundance and structure of denitrifying bacterial community in different activated sludge samples were assessed, where the abundance of denitrifying functional genes showed nirS in the range of 10(4)-10(5), nosZ with 10(4)-10(6) and 16S rRNA gene in the range 10(9)-10(10) copy number per ml of sludge. The culturable approach revealed Pseudomonas sp. and Alcaligenes sp. to be numerically high, whereas culture independent method showed betaproteobacteria to dominate the sludge samples. Comamonas sp. and Pseudomonas fluorescens isolates showed efficient denitrification, while Pseudomonas mendocina, Pseudomonas stutzeri and Brevundimonas diminuta accumulated nitrite during denitrification. Numerically dominant RFLP OTUs of the nosZ gene from the fertilizer factory sludge samples clustered with the known isolates of betaproteobacteria. The data also suggests the presence of different truncated denitrifiers with high numbers in sludge habitat.

The concept of an intraductal approach to evaluate the breast microenvironment assumes direct access to the cancer-containing duct. Central duct access to the cancer-affected lobe is essential if cytology or cell markers are to be useful indicators of pre-malignant change. Access to the cancer-bearing lobe would be less important if field change effects of malignant change were predominantly supra-lobar. The aim of this study was to determine how often duct lavage fluid drains the breast cancer-affected segment. 58 patients undergoing mastectomy for breast cancer were recruited among which 47 had at least one fluid-yielding duct. Following duct lavage, fluid-yielding ducts were perfused ex vivo with Polyurethane Elastomer (PU4ii) resin. Specimens were sliced sagittally, and the extent of resin perfusion and anatomical relationship to the cancer-affected segment was recorded. Computed tomography (CT) scanning was performed on selected mastectomies before cut-up for a feasibility study of 3D duct reconstruction. The median number of fluid-yielding ducts cannulated per cancer-affected breast was 2 (range 1-4). 35/47 (74%) mastectomy specimens were successfully cannulated for resin perfusion. 29/35 (83%) showed tracing of the cancer-affected duct system, 6/35 resin perfusions traced duct systems unaffected by cancer and 12/35 perfusions extravasated. The proportion of sagittal breast slices perfused by resin was 13-68%(median 43%). Volume rendering CT showed it is feasible to produce a simulated image of the perfused ducts. Duct access to the cancer-containing segment is feasible in the majority of patients. Fluid-yielding ducts proportionately drain a significant volume of the breast. Large symptomatic cancers may cause obstruction with distal collapse. Further quantitative study of breast perfusion CT scans may be helpful for estimating the volume fraction of breast tissue perfused by fluid-yielding ducts. The intraductal approach is a valid concept for biomarker assessment of cancer-containing breast segments.

Denitrification was compared between Paracoccus sp. and Diaphorobacter sp. in this study, both of which were isolated from activated sludge of a denitrifying reactor. Denitrification of both isolates showed contrasting patterns, where Diaphorobacter sp. showed accumulation of nitrite in the medium while Paracoccus sp. showed no accumulation. The nitrate reduction rate was 1.5 times more than the nitrite reduction in Diaphorobacter sp., as analyzed by the resting state denitrification kinetics. Increasing the nitrate concentration in the medium increased the nitrite accumulation in Diaphorobacter sp., but not in Paracoccus sp., indicating a branched electron transfer during denitrification. Diaphorobacter sp. was unable to denitrify efficiently at high nitrate concentrations from 1 M, but Paracoccus sp. could denitrify even up to 2 M nitrate. Paracoccus sp. was found to be an efficient denitrifier with insignificant amounts of nitrite accumulation, and it could also denitrify high amounts of nitrate up to 2 M. Efficient denitrification without accumulation of intermediates like nitrite is desirable in the removal of high nitrates from wastewaters. Paracoccus sp. is shown to suffice this demand and could be a potential organism to remove high nitrates effectively.

ABSTRACT: INTRODUCTION: Very few studies have investigated whether the time elapsed between surgical resection and tissue fixation or the difference between core-cut and excision biopsies impact on immunohistochemically measured biomarkers, including phosphorylated proteins in primary breast cancer. The aim of this study was to characterise the differences in immunoreactivity of common biomarkers that may occur (1) as a result of tissue handling at surgery and (2) between core-cuts and resected tumours. METHODS: Core-cuts taken from surgical breast cancer specimens immediately after resection (sample A) and after routine X-ray of the excised tumour (sample B) were formalin-fixed and paraffin-embedded and compared with the routinely fixed resection specimen (sample C). The variation in immunohistochemical expression of Ki67, oestrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor 2 (HER2), p-Akt and p-Erk1/2 were investigated. RESULTS: Twenty-one tissue sets with adequate tumour were available. Median time between collection of core-cuts A and B was 30 minutes (range, 20 to 80 minutes). None of the markers showed significant differences between samples A and B. Similarly, Ki67, ER, PgR and HER2 did not differ significantly between core-cuts and main resection specimen, although there was a trend for lower resection values for ER (P = 0.06). However, p-Akt and p-Erk1/2 were markedly lower in resections than core-cuts (median, 27 versus 101 and 69 versus 193, respectively; both P < 0.0001 [two-sided]). This difference was significantly greater in mastectomy than in lumpectomy specimens for p-Erk1/2 (P = 0.01). CONCLUSIONS: The delay in fixation in core-cuts taken after postoperative X-ray of resection specimens has no significant impact on expression of Ki67, ER, PgR, HER2, p-Akt or p-Erk1/2. However, extreme loss of phospho-staining can occur during routine fixation of resection specimens. These differences are likely attributable to suboptimal fixation and may have major repercussions for clinical research involving these markers.

With emphasis on thermal behavior in presence of different pH conditions and salts, the kinetic and thermodynamic parameters of purified polygalacturonase (PG) of E. carotovora subsp. carotovora (Ecc) BR1 were studied since characterization of an enzyme is significant in the context of burgeoning biotechnological applications. Thermodynamic parameters for polygalacturonic acid hydrolysis by purified PG were, deltaH*= 7.98 kJ/mol, deltaG*= 68.86 kJ/mol, deltaS*=-194.48 J/mol/K, deltaG(E-S)=-1.04 kJ/mol and deltaG(E-T)=-8.96 kJ/mol. Its turnover number (k(cat)) was 21/sec. Purified PG was stable in 20-50 degrees C temperature range and was deactivated at 60 degrees C and 70 degrees C. Thermodynamic parameters (deltaH*, deltaG*, deltaS*) for irreversible inactivation of PG at different temperatures (30-60 degrees C) were determined, where effectiveness of various salts and different pH (4-8) individually for thermal stability of PG were characterized. The efficacy of various salts for thermal stability of PG was in the following order: MgCl₂ >BaCl₂ >KCl >CaCl₂ >NaCl. Present work projects biochemical, thermodynamics of substrate hydrolysis as well as thermal stabilization parameters of PG from Ecc.

SUMMARY: Carotid endarterectomy(CEA) is being increasingly performed under regional anaesthesia supplemented with sedation, the world over. Deep or superficial cervical plexus blocks or a combination of both have been found to be equally effective. Various imaging modalities like fluoroscopy, computed tomography (CT), CT-fluoroscopy, ultrasound etc have been used to increase the success rates of the technique and to reduce the rate of complications associated with the block. These are especially useful given the varying landmarks quoted by various authors as also inter-individual differences in anatomy. We present a case report of how fluoroscopy aided us in administering cervical plexus block.

Lichenysins are most potent anionic cyclic lipoheptapeptide biosurfactants produced by Bacillus licheniformis on hydrocarbonless medium with mainly glucose as carbon source. They have the capacity to lower the surface tension of water from 72 to 27 mN/m. Based on species specific variations they are named lichenysin A, B, C, D, G and surfactant BL86. The lowest ever interfacial tension against decane of 0.006 mN/m is obtained with acid precipitated lichenysin B. Surfactant BL86 and lichenysin B have recorded lowest ever CMC of 10 mg/L by any surfactant under optimal conditions. Surface and interfacial tension lowering ability bears significance in the context of oil recovery from oil reservoir. Similarity exists between structure and biosynthesis of surfactin and lichenysin. Surfactin being the most studied of the two, understanding its structure and biosynthesis gives an insight into the structure and biosynthesis of lichenysin. Lichenysin is synthesized by a multienzyme complex, lichenysin synthetase (LchA/Lic) encoded by 32.4 (26.6 kb) lichenysin operon lchA (lic). The structure of lichenysin and its operon indicate the nonribosomal biosynthesis with the same multifunctional modular arrangement as seen in surfactin synthetase SrfA. The lchA operon consists of lchAA-AC (lic A-C) and lchA TE (licTE) genes encoding the proteins LchAA, LchAB, LchAC and thioesterase LchA-TE. The licA (lchAA) gene is 10,746 bp and codes for a 3,582 amino acids protein, licB (lchAB) gene is 10,764 bp and codes for a similar sized protein, while licC (lchAC) gene is 3,864 bp and codes for protein containing 1,288 amino acid. The biotechnological potential of lichenysin in MEOR has triggered research on structure-activity relationship. Both the nature of peptide and fatty acid dictate the activity of the biosurfactant. Tailormade biosurfactant with desired attributes can be obtained from engineered synthetases. Basic studies are lacking on mechanism of biosynthesis by lichenysin synthetase however, studies on various aspects of lichenysin including regulation are expected to swell in coming years.

Bacterial biofilms adapt and shape their structure in response to varied environmental conditions. A statistical methodology was adopted in this study to empirically investigate the influence of nutrients on biofilm structural parameters deduced from confocal scanning laser microscope images of Paracoccus sp.W1b, a denitrifying bacterium. High concentrations of succinate, Mg(++), Ca(++), and Mn(++) were shown to enhance biofilm formation whereas higher concentration of iron decreased biofilm formation. Biofilm formed at high succinate was uneven with high surface to biovolume ratio. Higher Mg(++) or Ca(++) concentrations induced cohesion of biofilm cells, but contrasting biofilm architectures were detected. Biofilm with subpopulation of pillar-like protruding cells was distributed on a mosaic form of monolayer cells in medium with 10 mM Mg(++). 10 mM Ca(++) induced a dense confluent biofilm. Denitrification activity was significantly increased in the Mg(++)- and Ca(++)-induced biofilms. Chelator treatment of various biofilm ages indicated that divalent cations are important in the initial stages of biofilm formation.