Maxillofacial Reconstruction With Three Dimensional Resin Bone Substitutes as an Alternative to Transition Group of Metals: A Structured Review.

In recent years, novel technologies and techniques have allowed today the production of controlled architecture materials. Although autogenous bone graft substitutes remain the gold standard, enormous defects require supplementary alloplastic substitutes for reconstruction. Polymers have lately been explored for the same purpose and their biological performance has been under research since the last decade. The aim of this review is to analyse maxillofacial reconstruction with three-dimensional resin bone substitutes. A Problem Intervention Comparison Outcomes (PICO) analysis was done and a search was carried out in the Cochrane Database, PubMed, Google Scholar etc databases and a hand search was done to collect the related literature. All articles for maxillofacial reconstruction with three-dimensional resin bone substitutes were scrutinised. The manuscripts published from 1990 till May 2021, were included in this review. A total of 106 articles were obtained from a PICO-based keyword search, and 91 manuscripts were retrieved after excluding the duplicates. Out of these 57 manuscripts were excluded on the basis of title and abstract. From the remaining 34 studies, 17 were excluded after reading the full text based on the inclusion and exclusion criteria. During data extraction, four studies were removed and finally, 13 studies were included in this research. From this scoping review, we could conclude that polymethylmethacrylate and polylactic acid formulations are very promising resin bone substitutes for 3-dimensional reconstruction of maxillofacial defects. However, rigorous long-term clinical trials are needed to validate this conclusion.

A study of genetic variants, genetic risk score and DNA methylation of PNPLA3 and TM6SF2 in alcohol liver cirrhosis.

BACKGROUND: Genetic and epigenetic factors are associated with the development of alcohol-associated liver disease (AALD). The single nucleotide polymorphisms (SNPs), rs738409 in Patatin-like phospholipase domain-containing protein (PNPLA3) and rs58542926 in Transmembrane 6 Superfamily Member 2 (TM6SF2) are strongly associated with AALD in different global populations, Hence, we analyzed the genetic risk score for these variants and deoxyribonucleic acid (DNA) methylation levels of the PNPLA3 and TM6SF2 genes among cases (alcohol liver cirrhosis) and controls (heavy drinkers without cirrhosis). METHOD: We studied patients with alcohol use disorder (AUD) with cirrhosis (AUD-C + ve, n = 136) and without cirrhosis (AUD-C-ve, n = 107) drawn from the clinical services of St. John's Medical College Hospital (SJMCH) (Gastroenterology and Psychiatry) and Centre for Addiction Medicine (CAM), National Institute of Mental Health and Neurosciences, (NIMHANS). Genotype data was generated for rs738409 (PNPLA3) and rs58542926 (TM6SF2) and used to calculate unweighted genetic risk score (uGRS) and weighted genetic risk scores (wGRS). DNA methylation levels were estimated by pyrosequencing at PNPLA3 and TM6SF2 loci. RESULTS: Overall we observed a significantly higher genetic risk score (weighted genetic risk score, wGRS) in individuals with alcohol use disorder compared to control population (p = < 0.01). Further, uGRS and wGRS were associated with the diagnosis of cirrhosis, even after correcting for age of onset, quantity and frequency of drinking. We also found hypomethylation at CpG2 of TM6SF2 gene in AUD-C + ve compared to AUD-C-ve (P = 0.02). CONCLUSION: We found that a genetic risk score based on SNPs in the PNPLA3 and TM6SF2 genes was significantly associated with cirrhosis in patients with AUD, suggesting a potential utility in identifying patients at risk and providing pre-emptive interventions. These may include interventions that aim to alter DNA methylation, which may be one of the mechanisms through which elevated genetic risk may influence the development of cirrhosis.

Reduced graphene oxide supported ZnO quantum dots for visible light-induced simultaneous removal of tetracycline and hexavalent chromium.

Semiconducting nanomaterials play an important role in the photocatalytic removal of aqueous pollutants like heavy metals, organic compounds, pathogens and antibiotics. In this study, we prepared ZnO quantum dots (QD) by the precipitation method and ZnO/rGO materials with varying percentages (0.5-2 wt%) of ZnO were prepared by the hydrothermal method. The synthesized catalysts were characterized by various physicochemical techniques, such as powder X-ray diffraction (XRD), Raman spectroscopy, ultraviolet-visible-diffuse reflectance spectroscopy (UV-VIS-DRS), Transmission Electron Microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR) and Brunauer-Emmett-Teller (BET) analysis to determine the structural as well as textural and surface properties. The photocatalytic activity of the prepared catalysts was analyzed during the individual and simultaneous removal of tetracycline (TC) and hexavalent chromium [Cr(vi)] in aqueous medium. Among all the catalysts, 1.5 wt% ZnO/rGO showed the highest visible light activity, where 68% tetracycline and 84% Cr(vi) abatement was observed after 120 min irradiation time. Moreover, tetracycline showed 70% mineralization. The photocatalytic activity is explained based on the photo-generated electron transfer from the conduction band (CB) of ZnO to the surface of rGO which prevents the recombination of excitons and produces OH˙ and O2 -˙; these radicals play an important role in degrading the TC and Cr(vi). The mechanism suggested that the co-existence of oxidizable and reducible species such as TC and Cr(vi) ensured the effective use of the photo-generated electrons and holes that leads to the efficient oxidation of TC and Cr(vi) reduction.

Association of Posterior Maxillary Bone Height and Dental Implant Placement: An Institutional Study.

This study evaluates the success of dental implants placed in the maxillary posterior region and whether an association exists regarding length and implant success. Dental implants are a surgical component that interfaces with jaw bone to support dental prostheses. In 1978, Brandmarks presented a two-stage threaded titanium root-form implant that has become the best-maintained dental implant. Differences in anatomy make treatment for posterior quadrants more challenging than that for anterior quadrants. The need for dental implants includes partial/complete edentulousness, tooth loss during a mixed dentition period, and immediate replacement due to trauma. This retrospective study was conducted as an institutional setting, and all patients undergoing implant surgery in the maxillary posterior region were considered. We performed Excel tabulation and data analysis using Statistical Package for the Social Sciences (IBM, Armonk, NY). Results show that posterior maxilla bone height was greater in females than males. Patients aged 41-50 yr with bone height of 12-14 mm occurred most often. For implant placement, females showed significant bone height in the posterior maxillary region, and age did not play a significant part in posterior bone height.

A Clinical Study of Effect of Hyperpyrexia on Otoacoustic Emissions in Children.

Various degrees of sensory neural hearing loss can be seen in the progression of some hereditary periodic fever syndromes. Otoacoustic emission testing can help to establish the inner ear involvement at an early period of a periodic fever with a risk of hearing loss (Abdul Kadir et al. in J Int Adv Otol 9(2.79):08-11, 2014). Sensorineural hearing loss is the common most complication of bacterial meningitis in childhood (Richardson in Pediatrics 102(6):1364-1368, 1998). When present from birth, or acquired in the pre-school years, hearing loss of any degree, even mild hearing loss, interferes with speech and language development. In addition to obvious communication deficits, the consequences of hearing loss in children and adults include psychosocial problems, such as frustration, irritability, anxiety, the tendency to withdraw from social interactions, and even depression (Dhar and Hall in Otoacoustic emissions: principles, procedures, and protocols, Plural Publishing, San Diego, 2011). OAE are acoustic signals emitted from cochlea to the middle ear and into the external ear where they are recorded. Evoked OAE are undetectable when deafness is above 30-35 dB Sound pressure level (Biswas in Clinical audio-vestibulometry for otologists and neurologists, Bhalani Publishing House, Mumbai, 1995). OAEs permit early detection of inner ear abnormalities associated with a wide variety of diseases and disorders, including Alport syndrome etc. With early detection, the serious consequences of hearing loss can sometimes be prevented. With proper identification and diagnosis of hearing impairment, timely and effective management for the same can be taken. Data for this study was collected from children (5-14 years) attending the Department of Otorhinolaryngology and Paediatrics Out-patient departments in P.E.S.I.M.S.R, Kuppam. Among the study population 43 (57.3%) were male and 32 (42.7%) were females showing the slight male preponderance. study was done on children with temperature > 1000 F, children with temperature were screened with OAE, and OAE was recorded in same children once fever has subsided and results were compared. This is a new study where we compared same group of children with fever and once fever has subsided. In most other studies, study group was compared to the healthy control group. In our study, children with fever having abnormal FDP values at f1were 9, they reverted back to base line once fever has subsided. This shows that there is no much damage to inner ear at lower frequencies. Almost 47 abnormal FDP values at f2 reverted back to normal. At higher frequencies (f3 and f4), there is no much change in abnormal FDPs with fever and after fever has subsided, this shows that there is more damage to inner ear at higher frequencies. This study demonstrated that hyperpyrexia causes hearing loss in children with fever probably due to cochlear involvement. We conclude that OAE can be used as a screening tool in detecting hearing loss among children because the technique is simple, reproducible, not expensive, not time consuming also effectively narrows down the children with high chances of hearing loss thereby effectively improves the chances of early diagnosis and hence children can be rehabilitated early, making a marked change in their future.

A Study of Clinical Significance of the Depth of Olfactory Fossa in Patients Undergoing Endoscopic Sinus Surgery.

The endoscope has revolutionized the diagnosis and treatment of diseases of the nose and paranasal sinuses. Endoscopic sinus surgery (ESS), like all minimally invasive surgery, is designed to combine an excellent outcome with minimal patient discomfort. Successful outcome with minimal complications can only be achieved with good knowledge of the endoscopic anatomy, appropriate training in the procedure and the understanding of the anatomical variations. The intraoperative complications of ESS are bleeding and injury to surrounding structures commonly the orbital structures and fovea ethmoidalis. This is a hospital based prospective observational study with an objective to define the distribution of Keros classification of the depth of olfactory fossa and its asymmetrical distribution rates based on Keros type. Prospective study in a tertiary rural based hospital. 100 patients above the age of 10 years from October 2013 to March 2015 for a period of one year six months undergoing endoscopic sinus surgery in the Department of ENT, P.E.S. Institute of Medical Sciences and Research, Kuppam were chosen randomly. The data was collected from these patients who will met the inclusion criteria of the study and before undergoing endoscopic sinus surgery by subjecting them to CT scan of paranasal sinuses. It is observed that a total of 100 patients had been studied in which the mean age of the population is 36.65 + 13.36 years. Youngest patient was 12 years old and eldest patient was 70 years old. Among the patients 50(50%) were males and remaining 50(50%) were females with a female to male ratio is 1:1. In the present study, the depth of olfactory fossa ranged from 2.1 to 8.3 mm inclusive of both sides in 200 CT images with a mean height of 5.21 mm. Of the 200 sides measured, the distribution of Keros classification is as the following-Keros type I 39(19.5%), Keros type II 143(71.5%) and Keros type III 18(9%) sides. Based on these observations, type II is the most common Keros type prevalent followed by type 1 Keros type and the least prevalent is the type III Keros type in the studied population. In the present study, on considering sides separately, the right side olfactory fossa depth ranged from 2.1 to 8.3 mm with a mean height of 5.43 mm and the left side olfactory fossa depth ranged from 2.1 to 8.1 mm with a mean height of 4.98 mm. On the right side, of 100 sides measured, the distribution of Keros classification is as the following-Keros type I 19(19%), Keros type II 68(68%) and Keros type III 13(13%) sides. On the left side, of 100 sides measured, the distribution of Keros classification is as the following-Keros type I 25(25%), Keros type II 70(70%) and Keros type III 5(5%) sides. Based on these observations, type II is the most common Keros type prevalent followed by type 1 Keros type and the least prevalent is the type III Keros type in the studied population on both sides. In the present study, out of 100 patients 23 patients were having asymmetric olfactory fossa between right and left sides based on Keros type, where as remaining 77% had symmetric Keros type on right and left sides. Out of 23 patients, 16 patients were having lower or deep olfactory fossa on right side, where as remaining 7 patients were having lower or deep olfactory fossa on left side. Based on these observations, a lower or deep ethmoid roof occurred more frequently on the right side than on the left side. Wilcoxon matched pair signed rank test is applied to see the significant difference between depth of right and left olfactory fossae. Since P value is < 0.001 the depth of olfactory fossa is significantly different from each other. The present study presents a precise, quantitative analysis of the olfactory fossa and ethmoid roof position as well as individual asymmetry. This information may be useful during pre-operative evaluation of CT images, as well as intraoperatively. The surgeon's understanding of the anatomy of a patient's ethmoid roof and its possible variations is crucial for countering possible complication risks during endoscopic sinus surgery.

Amelanotic Melanoma in the Vicinity of Acquired Melanocytic Nevi and not Arising from Agminated Melanocytic Nevi: Masquerading as Pyogenic Granuloma.

Amelanotic melanoma (AMM) presenting as pyogenic granuloma and occurring in the vicinity of acquired melanocytic nevi is rare. Herein, we report such a manifestation in a 68-year-old male who presented with the painful red nodule and multiple pigmented patches involving the left great toe. Histopathological examination of skin biopsy taken from the nodule with an immunohistochemical study using HMB45 and S-100 confirmed the diagnosis of AMM. Biopsy from the pigmented patch near the nodule showed features of melanocytic nevus. Investigative work up revealed metastatic deposits in the left inguinal lymph node with no evidence of systemic involvement, placing him in malignant melanoma Stage IIIC of American Joint Committee on Cancer (AJCC) tumor node metastasis system. The development of AMM in the vicinity of acquired melanocytic nevi and manifesting as granuloma pyogenicum is unique in this case.

Can community-based integrated vector control hasten the process of LF elimination?

Community-based integrated vector control (IVC) using polystyrene beads (EPS) and pyrethroid impregnated curtains (PIC) as an adjunct to mass drug administration (MDA) was implemented for lymphatic filariasis elimination, in the filaria endemic villages of Tirukoilur, south India. In all the villages, MDA was carried out by the state health machinery, as part of the national filariasis elimination programme. Thirty-six difficult-to-control villages were grouped as, viz, MDA alone, MDA + EPS and MDA + EPS + PIC arms. Implementation and monitoring of IVC was carried out by the community. After 3 years of IVC, higher reductions in filariometric indices were observed in both the community and vector population. Decline in antigenaemia prevalence was higher in MDA + IVC as compared to MDA alone arm. Vector density dropped significantly (P < 0.05) in both the IVC arms, and nil transmission was observed during post-IVC period. Almost 53.8 and 75.8 % of the cesspits in MDA + EPS and MDA + EPS + PIC arms were closed by the householders, due to the enhanced awareness on vector breeding. The paper presents the key elements of IVC implementation through social mobilization in a LF prevalent area. Thus, community-based IVC strategy can hasten LF elimination, as it reduced the transmission and filariometric indices significantly. Indices were maintained at low level with nil transmission, by the community through IVC tools.

Fatal swine influenza A H1N1 and Mycoplasma pneumoniae coinfection in a child.

One of the most common causes of death in influenza patients is secondary bacterial pneumonia and the most common pathogens involved are Streptococcus pneumoniae, Staphylococcus aureus, and Haemophilus influenza. To diagnose co infection with bacteria in a H1N1 case can be difficult but should be strongly suspected in a child who present with influenza like illness and lower respiratory tract signs or symptoms. We report coinfection of Mycoplasma pneumoniae in swine influenza A H1N1 child who presented with extensive pneumonia and expired within 48 hours.

Impact on prevalence of intestinal helminth infection in school children administered with seven annual rounds of diethyl carbamazine (DEC) with albendazole.

BACKGROUND & OBJECTIVES: One third of the world's population is infected with one or more of the most common soil-transmitted helminths (STH). Albendazole (ALB) is being administered with diethyl carbamazine (DEC) in filariasis endemic areas to eliminate lymphatic filariasis (LF) and helminth infections. In this study, the cumulative impact of seven annual rounds of mass drug administrations (MDA) of DEC and ALB on STH infection in school children in selected villages in southern India was determined. METHODS: During 2001-2010, seven MDAs were implemented by the Tamil Nadu s0 tate h0 ealth d0 epartment, India. LF and STH infections were monitored in school children from 18 villages of the two treatment arms (viz, DEC alone and DEC+ALB). Kato-Katz cellophane quantitative thick smear technique was employed to estimate STH infections at three weeks, six months and one year post MDA. RESULTS: Prior to treatment, an overall STH prevalence was 60 per cent. After each MDA, infection markedly reduced at three weeks post-treatment in both the arms. The prevalence increased at six months period, which was maintained up to one year. After seven rounds of MDA, the infection reduced from 60.44 to 12.48 per cent in DEC+ALB arm; while the reduction was negligible in DEC alone arm (58.77 to 52.70%). INTERPRETATION & CONCLUSIONS: Seven rounds of MDA with DEC+ALB reduced the infection load significantly, and further sustained low level of infection for 10 years. However, complete parasite elimination could not be achieved. To curtail STH infection in the community, MDA should be regularized and environmental sanitation measures need to be improved by effective community-based campaigns.

Stability-Indicating RP-HPLC Method for Simultaneous Estimation of Enrofloxacin and Its Degradation Products in Tablet Dosage Forms.

The present work was the development of a simple, efficient, and reproducible stability-indicating reverse-phase high performance liquid chromatographic (RP-HPLC) method for simultaneous determination enrofloxacin (EFX) and its degradation products including ethylenediamine impurity, desfluoro impurity, ciprofloxacin impurity, chloro impurity, fluoroquinolonic acid impurity, and decarboxylated impurity in tablet dosage forms. The separation of EFX and its degradation products in tablets was carried out on Kromasil C-18 (250 × 4.6 mm, 5 µm) column using 0.1% (v/v) TEA in 10 mM KH2PO4 (pH 2.5) buffer and methanol by linear gradient program. Flow rate was 1.0 mL min(-1) with a column temperature of 35°C and detection wavelength was carried out at 278 nm and 254 nm. The forced degradation studies were performed on EFX tablets under acidic, basic, oxidation, thermal, humidity, and photolytic conditions. The degraded products were well resolved from the main active drug and also from known impurities within 65 minutes. The method was validated in terms of specificity, linearity, LOD, LOQ, accuracy, precision, and robustness as per ICH guidelines. The results obtained from the validation experiments prove that the developed method is a stability-indicating method and suitable for routine analysis.

The heparan sulfate editing enzyme Sulf1 plays a novel role in zebrafish VegfA mediated arterial venous identity.

Arterial and venous specification is critical for establishing and maintaining a functioning vascular system, and defects in key arteriovenous signaling pathways including VEGF (vascular endothelial growth factor) lead to congenital arteriopathies. The activities of VEGF, are in part controlled by heparan sulfate (HS) proteoglycans, significant components of the endothelial glycocalyx. The level of 6-O sulfation on HS polysaccharide chains, that mediate the interaction between HS and VEGFA, is edited at the cell surface by the enzyme SULF1. We investigated the role of sulf1 in vascular development. In zebrafish sulf1 is expressed in the head and tail vasculature, corresponding spatially and temporally with vascular development. Targeted knockdown of sulf1 by antisense morpholinos resulted in severe vascular patterning and maturation defects. 93 % of sulf1 morphants show dysmorphogenesis in arterial development leading to occlusion of the distal aorta and lack of axial and cranial circulation. Co-injection of vegfa165 mRNA rescued circulatory defects. While the genes affecting haematopoiesis are unchanged, expression of several arterial markers downstream of VegfA signalling such as notch and ephrinB2 are severely reduced in the dorsal aorta, with a concomitant increase in expression of the venous markers flt4 in the dorsal aorta of the morphants. Furthermore, in vitro, lack of SULF1 expression downregulates VEGFA-mediated arterial marker expression, confirming that Sulf1 mediates arterial specification by regulating VegfA165 activity. This study provides the first in vivo evidence for the integral role of the endothelial glycocalyx in specifying arterial-venous identity, vascular patterning and arterial integrity, and will help to better understand congenital arteriopathies.

Diagnostic Role of Platelet Lymphocyte Ratio(PLR) in Pancreatic Head Masses.

Masses in and around pancreas constitute an important clinical entity in gastrointestinal surgical practice. Most common being adenocarcinoma of head of pancreas followed by inflammatory masses due to chronic pancreatitis. Accurate diagnosis is of central importance as therapeutic strategies range from observation to complete surgical removal including total pancreatectomy.Several tumor markers are available which could help in prognostication and diagnosis of carcinoma pancreas. Carbohydrate antigen 19-9(CA 19-9) is traditionally accepted best marker available. The role of new tumor marker platelet lymphocyte ratio (PLR) has been defined recently in prognostication of carcinoma pancreas. Role of PLR in diagnosing and its efficacy after combining it with CA 19-9 is not known. The aim of study was to assess the demographics of histologically proven neoplastic and inflammatory pancreatic head masses in our department. To assess the role of CA19-9 and platelet lymphocyte ratio(PLR) in determining nature of pancreatic head mass. Data consisted of histologically proven 45 patients .23 having head mass due to chronic pancreatitis and 22 because of neoplastic lesions. Demographics in terms of age, sex, previous pain episodes, presence of jaundice, history of alcohol intake were compared in both groups. Also tumor markers CA 19-9 and PLR individually and in combination were compared in both groups. Cancer pancreas significantly (p < 0.001) occurred in older age group, was significantly associated with jaundice (p = 0.005) and weight loss (p < 0.001). Accuracy in diagnosis of cancer pancreas was similar with CA 19-9 and PLR (68.89 %), where as combining CA 19-9 with PLR showed increased sensitivity(81.82 %) and accuracy(71.11 %) in diagnosing cancer pancreas. Other combinations showed no advantage. PLR is at least as good as CA 19-9 as diagnostic marker to differentiate between malignant and inflammatory head mass of pancreas.

Internal nasal valve and its significance.

UNLABELLED: Internal nasal valve (INV) is the narrowest area, of the nose where turbulence of the inspiratory and expiratory current takes place. This study analysis the significance of INV with respect to health and disease. STUDY DESIGN: Descriptive study/Prospective study. Study Centre: Tertiary Centre. 150 students were followed for 2 years after noting the endoscopic anatomic details of INV. The students who reported due to sinus/ear disease during this follow up period were again noted. The type of INV in health and disease were analysed. Septal deviation at the INV is noted in most of the cases of sinus/ear disease. It is advisable to correct the abnormality of INV if present simultaneously while clearing the ear/sinus pathology.

Phytoplankton diversity in the Parangipettai coastal waters, southeast coast of India.

An investigation was carried out during June 2005 to May 2007 on hydrography, composition and community structure of phytoplankton including chlorophyll a in Parangipettai coastal waters (southeast coast of India). Air and surface water temperatures varied from 25.5 to 31.2 degrees C and from 25 to 29.3 degrees C, respectively. Salinity values varied from 5 to 33.1 per thousand and the pH ranged between 7.2 and 8.3. Dissolved oxygen content varied from 3.1 to 7.9 mg l(-1) while the light extinction coefficient values (LEC) ranged between 1.8 and 11.0 cm. The range of inorganic nutrients viz., nitrate, nitrite, phosphate and silicate were: 6.5 - 27.0 microM; 1.0 - 8.9 microM; 0.1 - 3.0 microM and 15.0 - 140 microM, respectively. The range of chlorophyll a was: 2.0 - 7.5 microg l(-1). Presently, 117 phytoplankton species representing different classes viz: Bacillariophyceae (66); Dinophyceae (22); Cyanophyceae (19); Chlorophyceae (7) and Chrysophyceae (3) were recorded. The phytoplankton cell abundance varied from 0.14 to 132 cells ml(-1), with peak diversity (3.52 bits ind.(-1)) during summer season. The maximum abundance was found during summer season coinciding with the stable hydrographical conditions. Canonical Correspondence Analysis was applied in this study for discriminating environmental factors effecting on phytoplankton community at species level.

Phytoplankton diversity in pichavaram mangrove waters from south-east coast of India.

The results of an investigation carried out during September 2002 to August 2003 on hydrography, composition and community structure of phytoplankton including chlorophyll 'a' (Chl-a) content and primary productivity (PP) of the Pichavaram mangrove (South-east coast of India) are reported. Atmospheric and surface water temperatures varied from 30.0 to 34.8 degrees C and from 29.7 to 34.2 degrees C respectively while the light extinction coefficient values (LEC) (K) ranged between 3.2 and 14.9. Salinity values varied from 9.6 to 35.4 per thousand and the pH ranged between 7.2 and 8.6. Variation in dissolved oxygen content was from 3.2 to 6.5 ml l(-1). The ranges of inorganic nutrients viz., nitrate, nitrite, phosphate and silicate were: 7-36.23, 0.31-5.46, 0.28-3.70 and 12.26-56 64 microM respectively Chlorophyll 'a' content ranged between 0.20 and 105.60 microg l(-1) and the ranges of gross and net primary productivities (PP) were: 16.54-826.8 and11.52-610.2 mg Cm(-3) hr(-1) respectively. Presently a total of 94 species of phytoplankton were identified. Among these, the diatoms formed predominant group. Population density of phytoplankton varied from 400 to 3,21,000 cells(-1). While the peak diversity (5.23 bits/ind.) of the phytoplankton was observed during summer season, the maximum population density was found during summer season coinciding with the stable hydrographical conditions.

Schwannoma of the hard palate.

Schwannoma or neurilemmomas are benign, slow-growing, usually solitary, encapsulated tumors. They originate from the schwann cells of the nerve sheath. Approximately 30-40% of head and neck tumors are schwannomas. Intraoral schwannomas constitute a mere 1%. Tongue is the commonest site of schwannomas intraorally. Here we report a rare case of a hard palate swelling which was histopathologically diagnosed as schwannoma. The lesion was completely excised intraorally.