Modification of bentonite with black cotton soil and carboxyl methyl cellulose for the enhancement of hydraulic performance of geosynthetic clay liners.

Geosynthetic clay liners (GCLs) are mostly used as flow barriers in landfills and waste containments due to their low hydraulic conductivity to prevent the leachate from reaching the environment. The self-healing and swell-shrink properties of soft clays (expansive soils) such as bentonite enable them as promising materials for the GCL core layers. However, it is important to modify their physico-chemical properties in order to overcome the functional limitations of GCL under different hydraulic conditions. In the present study, locally available black cotton soil (BCS) is introduced in the presence of an anionic polymer named carboxymethyl cellulose (CMC) as an alternative to bentonite to enhance the hydraulic properties of GCL under different compositions. The modified GCL is prepared by stitching the liner with an optimum percentage of CMC along with various percentages of BCS mixed with bentonite. Hydraulic conductivity tests were performed on the modified GCL using the flexi-wall permeameter. The results suggest that the lowest hydraulic conductivity of 4.58 × 10-10 m/s is obtained when 25% of BCS is blended with bentonite and an optimum 8% CMC and further addition of BCS results in the reduction of the hydraulic conductivity.

A system of radiological criteria for grading and prognosticating temporal lobe contusions.

INTRODUCTION: Temporal contusions are common in patients with head injuries and require close monitoring due to the propensity of these patients to deteriorate rapidly and fatally. This study attempts to introduce a radiological grading system for temporal lobe contusions and analyse its prognostic value so as to better identify patients at risk of deterioration. METHODS: The study was conducted as a cross-sectional observational study from April 2011-March 2017 on 42 patients with temporal lobe contusion. Each patients was graded according to the proposed system from a minimum of four to a maximum of 13 and then further grouped in three grades - grade 1 (score = 4), grade 2 (score 5-7) and grade 3 (score > 7) - and their clinical course was closely observed. RESULTS: The minimum and maximum scores observed were four and 11 respectively. The proposed grading system has statistically significant correlation to the Glasgow Coma Scale (p-value < 0.05). All patients in grade 1 (17) could be managed conservatively, while all those in grade 3 (five) needed immediate surgical intervention. Of 20 patients in grade 2, 11 had a score of 5-6 and did not require surgery, whereas nine patients had a score of seven and of these eight required delayed surgical intervention. This correlation was statistically significant (p-value < 0.05). CONCLUSION: The proposed temporal lobe contusion grading system is a good radiological tool to predict the clinical course of patients and thereby identify patients at higher risk of delayed deterioration.

Forty years of clinical excellence at the Dr A Lakshmipathi Neurosurgical Centre and Post-Graduate Institute of Neurological Surgery, Voluntary Health Services (VHS) Hospital.

The Achanta Lakshmipathi Neurosurgical Center (ALNC) and Post Graduate Institute of Neurological Surgery is a private teaching neurosurgical institution located in the VHS (Voluntary Health Services) Hospital Chennai. It has been a leader and trendsetter among the private academic neurosurgical training institutions, and because of its unique legacy, has influenced the progress of Neurosurgery in India. The center was the second neurosurgical Institute to be created by Prof. B Ramamurthi and has trained neurosurgeons in the unique ALNC school of Neurosurgery. The Institute has grown to become a centre of excellence in microsurgery, and spinal surgery and has become a training centre for neurosurgery since 1985. The unique humanitarian aspects of the Voluntary Health Services Hospital helped in bringing the best of Neurosurgery to all strata of society. Forty years after its inception, the ALNC continues its delivery of excellence in clinical neurosurgery and academics.

Does cerebellar flocculus size affect subjective outcomes in pediatric auditory brainstem implantation.

OBJECTIVES: The objectives of study was to 1) Describe relevant surgical anatomy in defining and accessing the lateral recess for placement of electrode, 2) Propose a working classification for grades of Flocculus; 3) To determine if different grades of cerebellar flocculus effects placement of ABI electrode and subjective outcomes in implantees. METHODS: Our study was a prospective study, and comprised of cohort of 12 patients who underwent ABI surgery via retrosigmoid approach between 1 Jan 2012 to 31 Dec 2014. All children with congenital profound sensorineural hearing loss with either absent cochlea or cochlear nerve were included in the study. Relevant anatomy was noted. We also noted down the difficulty encountered during the placement of ABI electrode. Auditory perception and speech intelligibility was scored post operatively for 1 year. RESULTS: Cerebellar flocculus was divided into 4 grades depending on the morphology of cerebellar flocculus. It was noted that Grade 3 & 4 flocculus (Group B) had difficult ABI electrode placement in comparison to Grade 1 & 2 flocculus (Group A). The subjective outcomes of Group A was better than Group B. However the p value was not statistically significant. CONCLUSION: Cerebellar flocculus can be graded depending on morphology and size. Flocculus of higher grades can make the placement of ABI electrodes difficult and adversely effects the postoperative subjective outcomes.

Effect of compositional heterogeneity on dissolution of non-ideal LNAPL mixtures.

The extent of dissolution of petroleum hydrocarbon fuels into groundwater depends greatly on fuel composition. Petroleum fuels can consist of thousands of compounds creating different interactions within the non-aqueous phase liquid (NAPL), thereby affecting the relative dissolution of the components and hence a groundwater plume's composition over long periods. Laboratory experiments were conducted to study the variability in the effective solubilities and activity coefficients for common constituents of gasoline fuels (benzene, toluene, p-xylene and 1,2,4-trimethylbenzene) (BTX) in matrices with an extreme range of molar volumes and chemical affinities. Four synthetic mixtures were investigated comprising BTX with the bulk of the NAPL mixtures made up of either, ethylbenzene (an aromatic like BTX with similar molar volume); 1,3,5-trimethylbenzene (an aromatic with a greater molar volume); n-hexane (an aliphatic with a low molar volume); and n-decane (an aliphatic with a high molar volume). Equilibrium solubility values for the constituents were under-predicted by Raoult's law by up to 30% (higher experimental concentrations) for the mixture with n-hexane as a filler and over-predicted by up to 12% (lower experimental concentrations) for the aromatic mixtures with ethylbenzene and 1,3,5-trimethylbenzene as fillers. Application of PP-LFER (poly-parameter linear free energy relationship) model for non-ideal mixtures also resulted in poor correlation between experimentally measured and predicted concentrations, indicating that differences in chemical affinities can be the major cause of deviation from ideal behavior. Synthetic mixtures were compared with the dissolution behavior of fresh and naturally weathered unleaded gasoline. The presence of lighter aliphatic components in the gasoline had a profound effect on estimating effective solubility due to chemical affinity differences (estimated at 0.0055 per percentage increase in the molar proportion of aliphatic) as well as reduced molar volumes (estimated at -0.0091 in the activity coefficient per unit increase in molar volume, mL/mol). Previously measured changes in activity coefficients due to natural weathering of 0.25 compares well to 0.27 calculated here based on changes in the chemical affinity and molar volumes. The study suggests that the initial estimation of the composition of a fuel is crucial in evaluating dissolution processes due to ideal and non-ideal dissolution, and in predicting long term dissolution trends and the longevity of NAPL petroleum plume risks.

Scenario-based modelling of mass transfer mechanisms at a petroleum contaminated field site-numerical implications.

Knowledge about distribution of dissolved plumes and their influencing factors is essential for risk assessment and remediation of light non-aqueous phase liquid contamination in groundwater. Present study deals with the applicability of numerical model for simulating various hydro-geological scenarios considering non-uniform source distribution at a petroleum contaminated site in Chennai, India. The complexity associated with the hydrogeology of the site has limited scope for on-site quantification of petroleum pipeline spillage. The change in fuel composition under mass-transfer limited conditions was predicted by simultaneously comparing deviations in aqueous concentrations and activity coefficients (between Raoult's law and analytical approaches). The effects of source migration and weathering on the dissolution of major soluble fractions of petroleum fuel were also studied in relation to the apparent change in their activity coefficients and molar fractions. The model results were compared with field observations and found that field conditions were favourable for biodegradation, especially for the aromatic fraction (benzene and toluene (nearly 95% removal), polycyclic aromatic hydrocarbons (up to 65% removal) and xylene (nearly 45% removal). The results help to differentiate the effect of compositional non-ideality from rate-limited dissolution towards tailing of less soluble compounds (alkanes and trimethylbenzene). Although the effect of non-ideality decreased with distance from the source, the assumption of spatially varying residual saturation could effectively illustrate post-spill scenario by estimating the consequent decrease in mass transfer rate.

Management of pediatric intracranial meningiomas: an analysis of 31 cases and review of literature.

OBJECTIVE: The purpose of this study is to understand the epidemiology, clinical features, behavior, and the prognostic factors that influence the outcome of intracranial meningiomas in children. METHODS: Thirty-one patients with age less than 18 years who underwent surgery for intracranial meningiomas during the period of at 1988-2012 at Voluntary Health Services Hospital, Chennai, India were studied. These formed 3.7 % of the total 831 cases of intracranial meningiomas operated at the institute. RESULTS: The study group included 22 (71 %) males and 9 (29 %) females. The mean age of presentation was 15 years, with the youngest being 9 months old. Two (6 %) had evidence of neurofibromatosis type 2 (NF2). The most common symptoms at presentation were seizures in 11 (35.5 %), weakness of limbs in 11 (35.5 %), and raised intracranial pressure in 10 (32 %). Convexity meningiomas were seen in 16 (51 %) and skull base in 15(49 %). Multiple meningiomas was seen in two (6 %) of the patients and intraventricular location was found in one patient (3 %). Two (6 %) had evidence of NF2. Gross total excision was achieved in 26 (83 %) and subtotal excision in 5 (17 %). WHO grade I was found in 20 (64 %) and higher grade was seen in 11 (36 %). The mean follow-up was 46.2 months. Recurrence was seen in 20 patients (64 %). In patients with higher grade or with recurrence resurgery and radiotherapy was given. Three (9 %) had multiple recurrences. On a mean follow-up of 46.2 months, 25 patients (81 %) were neurologically intact, 5 (16 %) were having moderated disability, and 1 (3 %) patient died. CONCLUSIONS: Childhood meningiomas are uncommon lesions with a slight male predominance. They can have a varied clinical presentation. Higher grade is found more frequently compared with adults. Gross total resection is the goal and in higher grade meningiomas radiotherapy helps as a good adjuvant. Though the rate of recurrence is high, resurgery and radiotherapy gives a good outcome.

Isolated skull base primary Ewing's sarcoma: an extremely rare location.

A 16-year-old boy presented with history of headache and blurring of distant vision. He had UMN facial paresis and papilledema. Imaging revealed a heterogenous space occupying lesion in the middle cranial fossa base with mass effect and midline shift and non homogenous contrast enhancement with erosion of the petrous bone. He underwent gross total excision of the lesion. Histopathology and immunohistochemistry were suggestive of skull base Ewing's sarcoma. Bone scan was done to rule out primary involvement of other extracranial location. We have discussed the epidemiology, presentation, management and prognosis of such cases.

Methanol extract of Bauhinia purpurea leaf possesses anti-ulcer activity.

OBJECTIVE: The aim of the present study was to determine the anti-ulcer activity of a methanol extract of Bauhinia purpurea leaf (MEBP). MATERIALS AND METHODS: MEBP was administered at doses of 100, 500 and 1,000 mg/kg and its effects on acute toxicity, absolute ethanol- and indomethacin-induced gastric ulceration, and pyloric ligation tests in rats were investigated. RESULTS: At a dose of 5,000 mg/kg, MEBP did not cause any signs of toxicity in rats when given orally. Oral administration of MEBP exerted anti-ulcer activity (p < 0.05) in all models tested. However, a dose-dependent protection was observed only in the indomethacin-induced gastric ulceration model. Histological studies supported the observed anti-ulcer activity of MEBP. In the pyloric ligation assay, MEBP significantly increased gastric wall mucus secretion (p < 0.05), but did not affect the acidity of the gastric contents. CONCLUSION: MEBP exhibited anti-ulcer activity, which could be due to the presence of flavonoids, saponins or other polyphenols, thereby validating the traditional use of B. purpurea in the treatment of ulcers.

Primary spinal intradural extramedullary lymphoma causing cauda equina syndrome.

We report a case of lumbar intradural extramedullary lesion in an 11-year-old boy who presented with cauda equina syndrome and acute bladder disturbance. He underwent emergency surgical resection of the lesion, which was proved to be a lymphoma by histopathology and immunohistochemistry. He has improved neurologically and after 1 year, he is leading a normal life with near normal neurological functions. This is the second case of primary spinal intradural extramedullary lymphoma. This is the first such case in the pediatric age group and causing cauda equina syndrome. We describe the characteristics of such tumors along with pathogenesis and management.

Invasive rhino-cerebral fungal granuloma.

BACKGROUND: Increased incidence of fungal infection has been reported globally in the recent years. Fungal infection of the central nervous system remains one of the most difficult diseases to treat and requires multi-modality intensive therapeutic strategies. MATERIALS AND METHODS: Retrospective analysis of case records of patients with confirmed skull base fungal granuloma treated at a tertiary hospital between 1988-2008. An attempt was made to stage the extent of skull base fungal granuloma based on neuroimaging, operative findings and course of the disease on serial follow-up. RESULTS: Thirty-three patients with skull base fungal granuloma were treated surgically during the study period. The mean age at presentation was 33.2 years and diabetes was a major predisposing factor. Eight patients expired in the first two months following surgical intervention due to flare-up of the disease. Eighteen patients who underwent grossly total excision had a mean progression-free survival (PFS) of 43 months and seven patients with subtotal excision had a mean PFS of 23 months. Better survival probability was noted in those patients who underwent total excision at surgery and received complete course of amphotericin. CONCLUSION: Total surgical excision with complete course of antimycotic drug therapy increases PFS. A better antimycotic drug with less toxicity and high efficacy with fungicidal property can make a difference in the outcomes of the disease.

Suboccipital segment of the vertebral artery: a cadaveric study.

OBJECTIVE: To study the course, relationships, branches and possible anomalies of the vertebral artery in the suboccipital region in adult Indian cadavers. MATERIALS AND METHODS: Twenty-one suboccipital segment vertebral artery specimens from embalmed, Indian adult cadavers were dissected and studied. Dissection was performed using microsurgical instruments and was carried out from the skin up to the vertebral artery in layers. The course, relationships and the branches of the vertebral artery were studied and measurements were taken using Vernier calipers. The readings obtained were corroborated with the measurements derived from the digital images using a computer. OBSERVATIONS: All the vertebral arteries had a tortuous course and were covered with rich venous plexuses. None of the specimens had an anomalous course. The artery was divided into a vertical segment (Vv) between C2 and C1 vertebra and a horizontal segment (Vh) from the C1 transverse foramina to its dural entry. The mean diameter of the artery was 4.8 mm. The shortest distance of Vv segment from the dural tube was 16.1 mm, and the distance from the C2 ganglion was 7.2 mm. The average length of the Vv segment was 15 mm and the average length of the Vh segment was 35.6 mm. The average of the shortest distance between the vertebral artery and the midline was 13.4 mm. CONCLUSION: The vertebral artery has a tortuous course and is prone to accidental iatrogenic injury, which can result in devastating neurological sequelae depending on contralateral vertebral artery flow. A thorough anatomical knowledge of this segment is essential for the surgeon who intends to operate in this area.

Evaluation of antibacterial activity, phenol and flavonoid contents of Thespesia populnea flower extracts.

Flavonoids which were reported as having many pharmacological activities, antimicrobial, antioxidant, cytotoxic, chemoprevention activities and they possess strong antiproliferative effects related to inhibition of cell cycle progression and apoptosis induction. On the basis of this Thespesia populnea (L.) Sol. Ex Correa (Family-Malvaceae) was selected and it is having the major composition of flavonoids and the antibacterial activity of methanolic extract of Thespesia populnea flowers was investigated by agar well diffusion method. Furthermore our phytochemical studies indicated that methanolic extract of Thespesia populnea flowers contains flavonoids, alkaloids, tannins and anthroquinone glycosides. Moreover the individual components were identified by thin layer chromatography and Rf value was compared with standard flavonoid quercetin. The total phenolic and flavonoid content studies were also quantified. The bacteria used for antibacterial study were Shigella flexneri (NCIM 4924), Rhodococcus terrae (NCIM 5126), Escherichiae coli (ATCC 11775), Streptococcus faecalis (NCIB 2406), Klebsiella pneumoniae (ATCC 13883),Brevibacterium luteum (NCIM 2923), Micrococcus flavum (NCIM 2376), Proteus mirabilis (NCIB 8268), Bacillus licheniformis (NCIM 2468), Micrococcus luteus (ATCC 2984), Flavobacterium devorans (NCIM 2581), Shigella sonei(ATCC 29930), Shigella boydii (ATCC 8700) and Shigella dysentriae (ATCC 13313).According to our results in the lowest tested concentration of 62.5 microg/ml and 125mug/ml 7.2% of the plant extract were active, 5% active in the concentration of 250 microg/ml, 75.7% active in the concentration of 500 microg/ml and 92.8% active at the concentration of 1000 microg/ml in a dose dependent manner.

Intracranial epithelioid hemangioendothelioma.

INTRODUCTION: Epithelioid hemangioendothelioma (EHE) is an uncommon soft-tissue vascular neoplasm. Although a well-defined entity outside the neuraxis, its intracranial occurrence is rare. Literature review revealed 35 reported cases till date. CASE REPORT: The authors report a case of intracranial EHE in a 15-year-old girl, who presented with a short history and unusual radiology. Following radical removal, the lesion recurred within 1 month and progressed to terminal stages. This tumor is thought to have an indolent intermediate malignancy potential and such rapid progression has not been reported so far.

Pharmacological actions of Thespesia populnea relevant to Alzheimer's disease.

Thespesia populnea (Malvaceae) is a large tree found in the tropical regions and coastal forests of India. Various parts of T. populnea are found to possess useful medicinal properties, such as antifertility, antibacterial, anti-inflammatory, antioxidant, purgative and hepatoprotective activity. The present study was undertaken to investigate the effects of T. populnea bark on cognitive functions, total cholesterol levels and cholinesterase activity in mice. A total of 312 mice divided into 52 different groups were employed in the present investigation. The ethanolic extract of T. populnea (TPE) was administered orally in three doses (100, 200 and 400 mg/kg) for 7 successive days to different groups of young and aged mice. The learning and memory parameters were assessed using elevated plus maze and passive avoidance apparatus. TPE (200 and 400 mg/kg, p.o.) showed significant improvement in memory of young and aged mice. TPE also reversed the amnesia induced by scopolamine (0.4 mg/kg, i.p.) and diazepam (1 mg/kg, i.p.). Furthermore, TPE reduced significantly the central (brain) cholinesterase activity in mice. TPE exhibited a remarkable cholesterol lowering property comparable to simvastatin (a standard drug) in the present study. Furthermore, we observed that, T. populnea bark possessed a powerful memory enhancing activity in mice. Since diminished cholinergic transmission and increased cholesterol levels appear to be responsible for development of amyloid plaques and dementia in Alzheimer patients, TPE may prove to be a useful medicine on account of its multifarious beneficial effects, such as memory improving property, cholesterol lowering, anticholinesterase and anti-inflammatory activity. Therefore, T. populnea bark appears to be a promising candidate for improving memory and it would be worthwhile to explore the potential of this plant in the management of Alzheimer patients.

Auditory brainstem implantation: The first Indian experience.

Multichannel auditory brainstem implants (ABI) are currently indicated for patients with neurofibromatosis type II (NF2) involving both vestibulocochlear nerves. The ABI helps bypass the damaged cochlear nerves and restores a level of auditory sensation via the electrical stimulation of the cochlear nucleus. The implant is usually placed in the lateral recess of the fourth ventricle at the time of tumor resection to stimulate the cochlear nucleus. We report a case of ABI done on a 15-year-old girl with bilateral vestibular schwannomas.

Synthesis and study of antibacterial and antifungal activities of novel 1-[2-(benzoxazol-2-yl)ethoxy]- 2,6-diarylpiperidin-4-ones.

Some novel benzoxazolylethoxypiperidones have been synthesized and their antibacterial activity against streptococcus faecalis, bacillus subtilis, escherichia coli, staphylococcus aureus aand pseudomonas aeruginosa and antifungal activity against Candida-6, Candida albicans, Aspergillus niger, Candida-51 and Aspergillus flavus were evaluated. Compounds 37, 38 and 39 exerted potent in vitro antibacterial activity against Streptococcus faecalis while compounds 40 and 41 exhibited potent in vitro antifungal activity against Candida-51.

Posttraumatic total dislocation of the upper thoracic spine.

BACKGROUND: Difficulty in proper visualization of the upper thoracic spine in plain radiographs allows for injuries at this level to be missed, especially in a busy trauma center. This window of error is increased when the patient presents with no symptoms or signs of neurologic or spinal involvement, as upper thoracic dislocations commonly present early. CASE DESCRIPTION: The authors report a 19-year-old girl who developed progressive paraparesis 18 hours following initial presentation with a scalp avulsion injury. Imaging revealed a complete dislocation at T1-T2, with cord compression. Emergency surgical decompression and reconstruction of her spinal column was performed with a 360-degree stabilization. There was immediate neurologic improvement and on follow-up the patient is neurologically normal. CONCLUSIONS: The case highlights the difficulty in visualization of the upper thoracic spine in routine radiographs taken in a casualty setting. Treating physicians should have a low threshold for investigation of cervico-thoracic dislocations. The possibility of a delayed progressive dislocation should be kept in mind when dealing with injuries with a potential for spinal injury.

Idiopathic chronic hypertrophic pachymeningitis causing thoracic cord compression.

Chronic idiopathic pachymeningitis is a rare cause of compressive myelopathy, especially of the thoracic spinal cord. The hypertrophic dura causes symptoms either by pressure on the spinal cord or by vascular compromise. The authors report the diagnostic dilemmas in a 48-year-old lady who presented with progressive spastic paraparesis of 4 months duration. MRI showed an extradural hypointense band, surrounding and flattening the thoracic cord in the anteroposterior direction, extending from C7 to T11. Neither the CT scan nor the myelogram provided any clue to the diagnosis. A T1-T10 laminectomy was performed. The dura was hypertrophied and found compressing the cord. The posterior dura was excised and the spinal cord was decompressed. The histopathology showed hypertrophic pachymeningitis. The patient improved neurologically. She was started empirically on anti-tubercular chemotherapy, though she was serologically negative for all known causes of pachymeningitis.