Manual Instruments as an Alternative to Drilling for Bony Exposure in Skull Base Surgery: Concept and Technique.

Background Drilling in neurosurgery is an integral part of surgical exposure, especially in skull base approaches and craniovertebral junction (CVJ) surgeries. Most of such drillings are done in close proximity to the neurovascular structures in skull base surgeries and cervical-medullary junction or facet/pedicle in CVJ surgeries. Reluctance to drilling among young neurosurgeons is due to less hands-on experience during training and also, in the early part of the career, due to fear of injury to neurovascular structures. Methods Five commonest bone removals for skull base region and CVJ surgeries that can be safely done using manual instruments were identified based on experiences of senior authors. The authors highlight key technical nuances to widen surgical corridors using manual instruments safely for skull base surgical approaches. Results Basic neuroanatomical concepts and basic physics help in using manual instruments safely for bone removals in various skull base surgical approaches. Conclusions Manual instruments may be used for bone removals in selected skull base surgical approaches, which help young neurosurgeons to perform these surgeries in limited-resource settings.

Lignocellulolytic enzymes from Aspergillus allahabadii for efficient bioconversion of rice straw into fermentable sugars and biogas.

The study was aimed at developing lignocellulolytic strain capable of efficient hydrolysis of mild alkali deacetylated (MAD) rice straw. The valorisation of lignin rich black liquor obtained during pre-treatment of rice straw into biogas was also evaluated. Study reports highly proficient cellulolytic Aspergillus allahabadii strain harbouring a spectrum of CAZymes based on comparative genome wide analysis that was subjected to strain breeding for developing a hyper producing strain. The secretome analysis showed up-modulation and several folds increase in the CAZyme activities in the culture extracts of the developed strain MAN 40 when compared to parent. The cellulolytic cocktail of the developed strain showed 1.52 folds higher saccharification of MAD rice straw when compared to Cellic CTec 3. Moreover, in-situ addition of cellulases derived from developed strains resulted in ∼3.7 folds higher methane production during anaerobic digestion of mixture of lignin rich black liquor and differently treated rice straw.

Economizing the lignocellulosic hydrolysis process using heterologously expressed auxiliary enzymes feruloyl esterase D (CE1) and ß-xylosidase (GH43) derived from thermophilic fungi Scytalidium thermophilum.

Two lignocellulolytic accessory enzymes, feruloyl esterase D (FAED_SCYTH) and ß-xylosidase (XYL43B_SCYTH) were cloned and produced in the Pichia pastoris X33 as host. The molecular weight of recombinant enzymes FAED_SCYTH and XYL43B_SCYTH were ~ 31 and 40 kDa, respectively. FAED_SCYTH showed optimal activity at pH 6.0, 60 °C; and XYL43B_SCYTH at pH 7.0, 50 °C. FAED_SCYTH and XYL43B_SCYTH exhibited t1/2: 4 and 0.5 h, respectively (50 °C, pH 5.0). The ß-xylosidase was bi-functional with pronounced activity against pNP-α-arabinofuranoside besides being highly xylose tolerant (retaining ~ 97% activity in the presence of 700 mM xylose). Cocktails prepared using these enzymes along with AA9 protein (PMO9D_SCYTH) and commercial cellulase CellicCTec2, showed improved hydrolysis of the pre-treated lignocellulosic biomass. Priming of pre-treated lignocellulosic biomass with these accessory enzymes was found to further enhance the hydrolytic potential of CellicCTec2 promising to reduce the enzyme load and cost required for obtaining sugars from biorefinery relevant pre-treated substrates.

An innovative approach of priming lignocellulosics with lytic polysaccharide mono-oxygenases prior to saccharification with glycosyl hydrolases can economize second generation ethanol process.

Two Lytic polysaccharide Mono-Oxygenases (LPMOs), non-modular (PMO_08942) and modular (PMO_07920), from thermotolerant fungus Aspergillus terreus 9DR cloned and expressed in Pichia pastoris X33 and purified to homogeneity using ion-exchange chromatography were found to be of ~29 and ~40 kDa, respectively. Both LPMOs were optimally active at 50 °C; PMO_08942 was active under acidic condition (pH 5.0) and PMO_07920 at pH 7.0. Modular LPMO (PMO_07920) tethered to CBM-1 was found to be versatile as it showed appreciable activity on complex polysaccharide (both cellulose and xylans) as compared to non-modular (PMO_08942). The t1/2 of PMO_08942 (~192 h, pH 5.0) and PMO_0792 (~192 h, pH 7.0) at 50 °C, suggests highly stable nature of these LPMOs. Fluorescently tagged modular AA9 was studied microscopically to understand interaction with pretreated biomass. Priming of biomass for up to 6 h with LPMOs prior to initiating hydrolysis with core cellulase enzyme resulted in significantly higher saccharification.

Discovery and Expression of Thermostable LPMOs from Thermophilic Fungi for Producing Efficient Lignocellulolytic Enzyme Cocktails.

In this study, two novel thermostable lytic polysaccharide monooxygenases (LPMOs) were cloned from thermophilic fungus Scytalidium thermophilum (PMO9D_SCYTH) and Malbranchea cinnamomea (PMO9D_MALCI) and expressed in the methylotrophic yeast Pichia pastoris X33. The purified PMO9D_SCYTH was active at 60 °C (t1/2 = 60.58 h, pH 7.0), whereas, PMO9D_MALCI was optimally active at 50 °C (t1/2 = 144 h, pH 7.0). The respective catalytic efficiency (kcat/Km) of PMO9D_SCYTH and PMO9D_MALCI determined against avicel in presence of H2O2 was (6.58 × 10-3 and 1.79 × 10-3 mg-1 ml min-1) and carboxy-methylcellulose (CMC) (1.52 × 10-1 and 2.62 × 10-2 mg-1 ml min-1). The HRMS analysis of products obtained after hydrolysis of avicel and CMC showed the presence of both C1 and C4 oxidized oligosaccharides, in addition to phylogenetic tree constructed with other characterized type 1 and 3 LPMOs demonstrated that both LPMOs belongs to type-3 family of AA9s. The release of sugars during saccharification of acid/alkali pretreated sugarcane bagasse and rice straw was enhanced upon replacing one part of commercial enzyme Cellic CTec2 with these LPMOs.

Characterization of a novel Lytic Polysaccharide Monooxygenase from Malbranchea cinnamomea exhibiting dual catalytic behavior.

A novel Lytic Polysaccharide Monooxygenase (LPMO) family AA9 (PMO9A_MALCI) protein from thermophilic fungus Malbranchea cinnamomea was cloned and expressed in Pichia pastoris. The expressed protein was purified to homogeneity using ion exchange and hydrophobic interaction chromatography. SDS-PAGE analysis showed PMO9A_MALCI to be ~27 kDa protein. High performance anion exchange chromatography and mass spectrometry confirmed that purified protein was active against an array of cellulosic (avicel, carboxy methyl cellulose) and hemicellulosic (birch wood xylan, wheat arabinoxylan and rye arabinoxylan) substrates, releasing both oxidized and unoxidized cello-oligosaccharide and xylo-oligosaccharide products respectively. Presence of double oxidized products during mass spectrometric analysis as well as in-silico analysis confirmed that the expressed protein belongs to Type 3 LPMO family. Molecular dynamic simulations further confirmed the sharing of common amino acid residues conserved for catalysis of both cellulosic and hemicellulosic substrates which further indicates that both substrates are equally preferred. Enzymatic cocktails constituted by replacing a part of commercial cellulase CellicCTec2 with PMO9A_MALCI (9:1/8:2) led to synergistic improvement in saccharification of acid and alkali pretreated biomass. This is the first report on heterologous expression of LPMO from M. cinnamomea, exhibiting catalysis of cellulose and pure xylan.

A novel modification of the autoimplantation therapy for the treatment of multiple, recurrent and palmoplantar warts.

BACKGROUND: Ideal treatment for warts should be effective, safe, have less morbidity and provide long-lasting immunity against human papilloma virus. This can optimally achieved by the stimulation of the immune system against the virus. The autoimplantation of warts, autowart injection and quadrivalent vaccines have been used for this purpose. Autoimplanatation is a simple technique where the subcutis deep wart tissue is harvested as a donor and implanted into the uninvolved skin. However, this led to two wounds, at donor and recipient sites. AIM: The aim was to evaluate the safety and efficacy of a novel modification of autoimplantation therapy in the treatment of multiple, recurrent and palmoplantar warts. SUBJECTS AND METHODS: Thirty-three patients with multiple, recurrent and palmoplantar warts were enrolled. Instead of taking a bit of the wart tissue, the donor tissue was harvested by paring the wart. The pared tissue was implanted deep into the subcutis by stab incision done using the same surgical blade no. 11. The resolution of all warts within 3 months after the procedure was considered successful. Patients with complete clearance were followed up for 1 month for any recurrence. RESULTS: Out of 35 patients, 27 patients were available for follow-up. A total of 20 (74.1%) patients showed a complete clearance of warts within 3 months. Partial clearance was seen in 1 patient. Erythematous nodules developed at the site of implantation in 3 (11.1%) patients. There was relapse in one patient. CONCLUSION: A modified technique of autoimplantation of warts employing the pared stratum corneum tissue from the wart is a simple, effective, less traumatic and rapid procedure in the treatment of multiple, recurrent and palmoplantar warts.

Appraisal of transverse nasal groove: a study.

BACKGROUND: Transverse nasal groove is a condition of cosmetic concern which awaits due recognition and has been widely described as a shallow groove that extends transversely over the dorsum of nose. However, we observed variations in the clinical presentations of this entity, hitherto undescribed in literature. AIMS: We conducted a clinicoepidemiological study of transverse nasal lesions in patients attending our outpatient department. METHODS: We conducted a prospective observational study. We screened all patients attending our out-patient department for presence of transverse nasal lesions, signs of any dermatosis and associated other skin conditions. RESULTS: One hundred patients were recruited in the study. Females (80%) predominated over males. Most patients were of 15-45 years age group (70%). Majority of the transverse nasal lesions were classical transverse nasal groove (39%) and others included transverse nasal line (28%), strip (28%), ridge (4%) and loop (1%). Seborrhoeic diathesis was the most common condition associated with transverse nasal lesion. CONCLUSIONS: Occurrence of transverse nasal line, strip, ridge and loop, in addition to classical transverse nasal groove implies that latter is actually a subset of transverse nasal lesions. Common association of this entity with seborrheic dermatitis, seborrhea and dandruff raises a possibility of whether transverse nasal lesion is a manifestation of seborrheic diathesis.