Diagnostic Validity of Orthopantomogram Compared to Dual Energy X-ray Absorptiometry Scan in Detecting Osteoporosis

Introduction Osteoporosis is one of the most common and rampant metabolic bone disorders among the geriatric, particularly affecting postmenopausal women. Even though resorption tends to occur more rapidly in bones with a higher proportion of trabecular bone (e.g., vertebrae, pelvis, calcaneus), bones with significant cortical bone content also do undergo resorption, for example, mandible. The dental manifestations that may indicate low-bone density include loose teeth, receding gums, and ill-fitting or loose dentures.

Objective To validate the efficacy of orthopantomograms (OPGs) in recognizing bone mineral density (BMD) changes of the mandible using mandibular cortical index (MCI) and substantiate the same with dual energy X-ray absorptiometry (DEXA) scan on femoral neck and spine.

Materials and Methods This cross-sectional study comprised 60 geriatric patients of both genders. All the patients were subjected to panoramic radiographs wherever clinically indicated. The visual analysis was done based on the radiographic appearance of the mandibular cortical border and results were compared with DEXA scan reports, followed by an analysis of three grades of MCI and BMD statistically.

Results In our study, out of 40 patients in C2 and C3 subgroups, 67% and 20% were normal, respectively. The incidence of osteopenia was 33% in the C2 group and 70% in the C3 group, whereas Osteoporosis was present only among 10% of the population in the C3 group. The difference between the groups are statistically significant (p = 0.01). These findings imply that a progressive link exists between BMD and deteriorating cortical morphology.

Conclusion The purpose of this study is that dentists will be able to refer patients to physicians of suspected low BMD, based on incidental findings on panoramic radiographs for further examination. There is a statistically significant correlation present between DEXA and MCI, so the latter can also be used for screening BMD changes.

Genomic, epigenomic, and biophysical cues controlling the emergence of the lung alveolus

The lung alveolus is the functional unit of the respiratory system required for gas exchange. During the transition to air breathing at birth, biophysical forces are thought to shape the emerging tissue niche. However, the intercellular signaling that drives these processes remains poorly understood. Applying a multimodal approach, we identified alveolar type 1 (AT1) epithelial cells as a distinct signaling hub. Lineage tracing demonstrates that AT1 progenitors align with receptive, force-exerting myofibroblasts in a spatial and temporal manner. Through single-cell chromatin accessibility and pathway expression (SCAPE) analysis, we demonstrate that AT1-restricted ligands are required for myofibroblasts and alveolar formation. These studies show that the alignment of cell fates, mediated by biophysical and AT1-derived paracrine signals, drives the extensive tissue remodeling required for postnatal respiration.

Thermo mechanical and Control Behaviour of Copper based Shape Memory Alloy Bimorph Actuator towards the Development of Micro Positioning System

A shape memory alloy (SMA) bimorph actuator is a composite structure composed of flexible polyimide substrate and SMA thin film deposited using thermal evaporation technique. In this work, the substrate thickness in the range of 25 - 75 mm was selected for the development of CuAlNiMn SMA bimorph actuator. An investigation on the control behavior of copper based SMA bimorph towards the development of micro positioning system has been performed. The actuation behavior of the SMA bimorph was studied using electrical actuation. Subsequently, a proportional integral derivative (PID) controller was designed to control the bimorph actuator with proper tuning of gain parameters. The displacement of the bimorph actuator was controlled through dedicated experimental setup consisted of laser displacement sensor, data acquisition system and LabVIEW software. The CuAlNiMn SMA bimorph actuator resulted in a satisfying control performance which can be extended to MEMS applications. A preliminary prototype of the SMA bimorph actuator based micro positioning system has been developed.

STAT3-BDNF-TrkB signalling promotes alveolar epithelial regeneration after lung injury

Alveolar epithelial regeneration is essential for recovery from devastating lung diseases. This process occurs when type II alveolar pneumocytes (AT2 cells) proliferate and transdifferentiate into type I alveolar pneumocytes (AT1 cells). We used genome-wide analysis of chromatin accessibility and gene expression following acute lung injury to elucidate repair mechanisms. AT2 chromatin accessibility changed substantially following injury to reveal STAT3 binding motifs adjacent to genes that regulate essential regenerative pathways. Single-cell transcriptome analysis identified brain-derived neurotrophic factor (Bdnf) as a STAT3 target gene with newly accessible chromatin in a unique population of regenerating AT2 cells. Furthermore, the BDNF receptor tropomyosin receptor kinase B (TrkB) was enriched on mesenchymal alveolar niche cells (MANCs). Loss or blockade of AT2-specific Stat3, Bdnf or mesenchyme-specific TrkB compromised repair and reduced Fgf7 expression by niche cells. A TrkB agonist improved outcomes in vivo following lung injury. These data highlight the biological and therapeutic importance of the STAT3-BDNF-TrkB axis in orchestrating alveolar epithelial regeneration.

Development of Sn-doped ZnO based ecofriendly piezoelectric nanogenerator for energy harvesting application

In this work, we have a demonstrated zinc oxide (ZnO) polymer-based ecofriendly piezoelectric nanogenerator (PENG) on a paper substrate for an energy harvesting application. The ZnO thin film is developed on the paper substrate, where different doping concentrations of Sn have been investigated systematically to validate the effect of doping towards enhancing the device performance. The piezoelectric potential of the fabricated device is evaluated by applying three different loads (4 N, 8 N, 22 N), where the source of the corresponding mechanical loads is based on the object of a musical drum stick. The results suggest that the pristine ZnO PENG device can generate a maximum output voltage and current of 2.15 V and 17 nA respectively. Moreover, the ZnO PENG device doped with 2.5% Sn achieved an even higher voltage (4.15 V) and current (36 nA) compared to pristine ZnO devices. In addition, the hydrothermal growth technique used to develop Sn-doped ZnO has the benefits of high scalability and low cost. Hence, the Sn-doped PENG device is a suitable candidate for energy harvesting applications operating in both uniform and non-uniform loading conditions.

Efficacy of Bromelain along with Trypsin, Rutoside Trihydrate Enzymes and Diclofenac Sodium Combination Therapy for the treatment of TMJ Osteoarthritis - A Randomised Clinical Trial

INTRODUCTION

Osteoarthritis (OA) is a degenerative disorder characterized by chronic inflammatory response of cartilage and articular surface involving Temporomandibular Joint (TMJ). Pain as one of the major symptom of osteoarthritis affects the quality of life and is usually managed by Non Steroidal Anti Inflammatory Drugs (NSAIDs) such as diclofenac sodium. Bromelain, trypsin and rutoside trihydrate formulation can be used to treat this disease because of anti-inflammatory and anti-oxidant effects.

AIM

To assess the effectiveness of oral bromelain, trypsin, rutoside trihydrate enzymes and diclofenac sodium combination therapy over diclofenac sodium for the treatment of TMJ osteoarthritis.

MATERIALS AND METHODS

Thirty Patients with symptomatic TMJ osteoarthritis were randomly divided into three groups. 10 patients were treated with diclofenac sodium (Group 1), 10 were given oral enzymes (bromelain, trypsin, rutoside trihydrate) and diclofenac sodium combination (Group 2), and 10 were treated with oral enzyme preparation (bromelain, trypsin, rutoside trihydrate) (Group 3). Patients were evaluated on day 1, day 4, day 7 and day 10. Comparison of pain rating within three groups was assessed using numeric rating scale. The efficacy criteria were analysed applying ANOVA followed by post-hoc test.

RESULTS

Inter group comparison of the effectiveness of management of pain, resulted in a value p < 0.05 between Group 2 and other two groups, which indicated that Group 2 patients responded better than Group 1 and Group 3, while p > 0.05 between Group 1 and Group 3 showed both groups responded equally to the treatment.

CONCLUSION

The trial showed significant improvement in reducing pain in patients treated with oral enzymes and diclofenac sodium combination therapy.

Dilated odontoma: A report of two cases from a radiological perspective

Dilated odontoma is the most extreme form of dens invaginatus. The lesion appears as a roughly spherical mass that does not resemble a tooth but in a way appears tooth - like on radiographs due to somewhat similar radiodensity. The lesion is mostly spherical in appearance and hence the term “dilated.” Occasionally, we come across cases of simultaneous pathologies. Here, we report two cases of a dilated odontoma one of which is associated with dentigerous cyst and in other case dilated odontoma pushing the maxillary sinus superiorly. Histologically, the mass was composed of dentinal tubules. These morphological and histological features are compatible with those of a dilated odontoma.

Idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP) is defined as a hematologic disorder, characterized by isolated thrombocytopenia without a clinically apparent cause. The major causes of accelerated platelet consumption include immune thrombocytopenia, decreased bone marrow production, and increased splenic sequestration. The clinical presentation may be acute with severe bleeding, or insidious with slow development with mild or no symptoms. The initial laboratory tests useful at the first visit to predict future diagnosis were erythrocyte count, leukocyte count, anti-glycoprotein IIb/IIIa antibodies, reticulated platelets, plasma thrombopoietin level. Treatment should be restricted to those patients with moderate or severe thrombocytopenia who are bleeding or at risk of bleeding. We present a case report on ITP with clinical presentation, diagnosis and management.

Comparative profile of circulating antigenic peptides in CSF, serum & urine from patients with neurocysticercosis diagnosed by immunoblotting

Traditionally serum and/or CSF specimens have been used for detection of either specific antibodies or antigens as a supportive diagnosis of NCC. However, in recent days, much interest has been shown employing noninvasive specimens such as urine. In our study, we identified and compared a profile of circulating antigenic peptides of parasite origin in three different body fluids (CSF, serum and urine) obtained from confirmed NCC cases and control subjects. The circulating antigenic peptides were resolved by SDS-PAGE and subjected to immunoblotting. For confirmation of their origin as parasite somatic or excretory secretory (ES) material, immunoreactivity was tested employing affinity purified polyclonal Taenia solium metacestode anti-somatic or ES antibodies, respectively. Only lower molecular weight antigenic peptides were found circulating in urine in contrast to serum and CSF specimens. Few somatic peptides were identified to be 100% specific for NCC (19·5 kDa in all three specimens; 131, 70 kDa in CSF and serum only; 128 kDa in CSF only). Similarly, the specific ES peptides detected were 32 kDa (in all three specimens), 16·5 kDa (in serum and CSF only), and 15 kDa (urine only). A test format detecting either one or more of these specific peptides would enhance the sensitivity in diagnosis of NCC.

A comparative study on the diagnostic utility of ultrasonography with conventional radiography and computed tomography scan in detection of zygomatic arch and mandibular fractures

Objectives:

The objective of the following study is to evaluate the usefulness of ultrasonography (USG) in comparison with conventional radiography and computed tomography (CT) scan in the diagnosis of zygomatic arch and mandibular fractures.

Materials and Methods:

A total of 40 patients with suspected fracture of the zygomatic arch and/or mandibular fractures were included in the study. Two groups (one for zygomatic arch fractures and the other for mandibular fractures) of 20 patients each were designed for the study. Ultrasonographic examinations were performed using small linear probe (LA435, Siemens Acuson Antares) with 10 MHz frequency. Data from CT and conventional radiography were compared with that of USG.

Results:

Sensitivity and specificity of USG in assessing zygomatic arch fractures were 100% and 100%, respectively; and that of mandibular fractures were 94.74% and 100%, respectively. Overall sensitivity, specificity, positive predictive value, and negative predictive value of USG against CT in diagnosing zygomatic arch and mandibular fractures were found out to be 97.4%, 100%, 100%, and 66.7%, respectively.

Conclusion:

USG is a very reliable tool in detection of fractures involving zygomatic arch and mandible. It can be used for screening of suspected fractures of zygomatic arch and mandible to avoid unnecessary radiation exposure from conventional radiography and CT scans.

Autoimmune polyglandular syndrome type 1

Autoimmune Polyglandular Syndrome (APS) Type 1 is a rare hereditary disorder that damages organs in the body. This disease entity is the result of a mutation in the AIRE gene. It is characterized by three classic clinical features - hypoparathyroidism, Addison's disease, and chronic mucocutaneous candidiasis. For a patient to be diagnosed as having APS Type 1 syndrome at least two of these features needs to be present. The third entity may develop as the disease progresses. We report a case of a 35-year-old female patient with a history of seizure from the age of 11 years, who was managed with anticonvulsant drugs. With worsening of the seizure episodes, patient was diagnosed to have hypoparathyroidism together with the manifestations of oral candidiasis, nails dystrophy, enamel hypoplasia, and hypogonadism. A diagnosis of APS-1 was considered. The facility for genetic analysis of the AIRE gene mutation was not accessible, as the test costs were prohibitive and not affordable for the patient. Patient management was directed to treating individual disease components. However, cerebral and dental changes were irreversible.

Inhibitory effects of bioactive leads isolated from Pseudomonas aeruginosa PS3 and Pseudomonas fluorescens PS7 on MAP kinases and down regulation of pro inflammatory cytokines (TNF-α, IL-1β) and mediators (NO, iNOS and COX)

Pure lead molecules, showing anti-inflammatory effect were isolated from the marine Pseudomonas aeruginosa PS3 (GenBank Accession No. EF488968) and Pseudomonas fluorescens PS7 (GenBank Accession No. EF488969) using solvent extraction procedures, subsequent column fractionation, followed by bio activity based screening. The structures of the lead molecules (3S, 8aS)-3-isobutylhexahydropyrrolo[1,2-a]pyrazine-1,4-dione (Compound 1) and (8aS)-3-(4-hydroxybenyl) hexahydropyrrolo[1,2-a]pyrazine-1,4-dione (Compound 2) obtained from P. aeruginosa PS3 and P. fluorescens PS7 respectively were established employing spectral analysis. Compounds 1 and 2 at their IC(50) values of 84 and 53μM concentrations respectively down regulated expression of tumor necrosis factor-α (TNF-α) and interleukin 1-β (IL-1β) in peripheral blood mononuclear cells (PBMCs) and inducible nitric oxide synthase (iNOS) gene in RAW 264.7 cells. Immunoblot analysis revealed the inhibitory effect of pure compounds on phosphorylation of all the three mitogen activated protein kinases (MAPK) such as ERK, JNK and p38 MAPK. The results of the present investigation revealed that the pure compounds are anti-inflammatory in nature.

Regional odontodysplasia: report of a case

Regional odontodysplasia is an unusual nonhereditary dental anomaly of uncertain origin. It presents clinically as delayed or failed eruption, abscess formation, early exfoliation, and malformed teeth and radiographically as defective enamel and dentin formation, giving the teeth a fuzzy silhouette. Because teeth are essential for psychological and functional development of the child, appreciation and management of regional odontodysplasia is important for comprehensive dental care. The purpose of this paper was to present the case of a 12-year-old female who presented with an eruption disturbance affecting a single segment of her jaw and characteristic ghost teeth radiographic appearance. The approach toward management should be aimed at preserving the unerupted affected teeth for the development of the alveolar ridge, conserving the erupted teeth (if salvageable) or extraction followed by prosthetic rehabilitation.

Recombinant Gluconacetobacter diazotrophicus containing Cry1Ac gene codes for 130-kDa toxin protein

Recombinant Gluconacetobacter diazotrophicus containing Cry1Ac gene from Bacillus thuringiensis var. kurstaki borne on pKT230, shuttle vector, was generated. PCR amplification of Cry1Ac gene present in recombinant G. diazotrophicus yielded a 278-bp DNA product. The nitrogenase assay has revealed that the recombinant G. diazotrophicus in sugarcane stem produced similar levels of nitrogenase compared to wild-type G. diazotrophicus. The presence of 130-kDa protein in apoplastic fluid from sugarcane stem harvested from pots inoculated with recombinant G. diazotrophicus shows that the translocated G. diazotrophicus produces 130-kDa protein which is recognized by the hyperimmune antiserum raised against 130-kDa protein. The first instar Eldana saccharina neonate larvae that fed on artificial medium containing recombinant G. diazotrophicus died within 72 h after incubation.

Anti inflammatory potential of Decalepis hamiltonii (Wight and Arn) as evidenced by down regulation of pro inflammatory cytokines-TNF-alpha and IL-2

ETHNOPHARMACOLOGICAL RELEVANCE

Ancient tribes in the Western Ghats of India use the roots of Decalepis hamiltonii Wight and Arn (Asclepiadaceae) for several medicinal purposes particularly inflammation.

AIM

To investigate whether the pure compounds obtained from the Decalepis hamiltonii have anti inflammatory activity.

MATERIALS AND METHODS

The bioactive lead molecules from the roots of Decalepis hamiltonii were extracted into dichloromethane/methanol and purified by silica gel column chromatography. Structural elucidation of the purified compounds was performed with (1)H and (13)C NMR and mass spectrometry. The in vitro anti inflammatory activity of the pure compounds was studied in mitogen induced peripheral blood mononuclear cells (PBMCs) employing [(3)H] thymidine uptake assay and their effect on cytokine expression by reverse transcriptase polymerase chain reaction (RT-PCR). The inhibition of nuclear factor kappaB (NF-kappaB) activity in the presence of pure compounds was determined in J774 A.1 cells. The cytotoxicity of the compounds was tested using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay kit.

RESULTS AND DISCUSSION

Lupeol acetate (Compound 1) and (2S)-5,7,4'-trihydroxy flavanone 4'-O-beta-d-glucoside (Compound 2) isolated from Decalepis hamiltonii roots inhibited the proliferation of mitogen induced PBMCs with an IC(50) value of 8 and 0.5mug/ml respectively. MTT assay revealed the compounds to be non-cytotoxic. Though, both the compounds down regulated the synthesis of mRNA of the pro inflammatory cytokines, interleukin-2 (IL-2) and tumour necrosis factor-alpha (TNF-alpha), the anti inflammatory cytokine interleukin-10 (IL-10), was found to be up regulated. NF-kappaB activation in J774 A.1 cells were also inhibited by both the compounds.

CONCLUSION

Lupeol acetate and (2S)-5,7,4'-trihydroxy flavanone 4'-O-beta-d-glucoside isolated from Decalepis hamiltonii roots showed anti inflammatory activities by down regulating TNF-alpha and IL-2 specific mRNA, besides up regulating the synthesis of mRNA of IL-10.

Cherubism combined with epilepsy, mental retardation and gingival fibromatosis (Ramon syndrome): a case report

Cherubism is an inherited, autosomal dominant disorder that characteristically affects the jaws of children. The disease typically manifest as a bilateral swelling with associated submandibular lymph node enlargements and usually regresses as age advances. The disease is microscopically indistinguishable from other giant cell lesions and is essentially a clinical diagnosis. The association of cherubism with gingival fibromatosis, epilepsy, mental retardation, stunted growth, and hypertrichosis is referred as Ramon syndrome. We report a case of Ramon syndrome in an 8 year old girl.

Progeria

Hutchinson Gilford Progeria Syndrome (HGPS) is a rare, sporadic, autosomal dominant syndrome that involves premature ageing and death at early age due to myocardial infarction or stroke. A 30-year-old male with clinical and radiologic features highly suggestive of HGPS is presented here with description of differential diagnosis, dental considerations and review of literature.

Correlations between genotyping and antibiograms of clinical isolates of Pseudomonas aeruginosa from three different south Indian hospitals

PURPOSE

To compare the molecular relationships and antibiograms of nosocomial isolates of Pseudomonas aeruginosa obtained from three different genres of hospitals located in Southern India, two located at Hyderabad (one private hospital and an ophthalmic hospital) and one in Puducherry (tertiary care teaching hospital). Each of these hospitals, which follow different infection control strategies and various problems associated with it, were investigated.

MATERIALS AND METHODS

Antibiograms generated by disk diffusion susceptibility testing for clinically relevant antibiotics and genotyping through fluorescent amplified fragment length polymorphism analysis (fAFLP) were the tools used in the study.

RESULTS

Molecular genotyping revealed a heterogeneous group of unrelated molecular clusters of P. aeruginosa strains having higher resistance that are apparently being endemic throughout the tertiary care teaching hospital. In eye care hospital, only a few distinct strains of P. aeruginosa predominating the study period were shown to be responsible for outbreaks. The third private hospital witnessed a group of resistant and persistent strains that might have clonally originated from a diverse collection of strains.

CONCLUSIONS

The divergent kind of strains in our study suggests that there may be a direct link between the infection control practices followed in each hospital and kind of strains isolated in that particular setup. The study also emphasizes the need for maintaining infection control practices in hospitals with superior standards, failure of which might result in thriving of persistent P. aeruginosa clones in the hospitals.

Detection of pneumolysin and autolysin genes among antibiotic resistant Streptococcus pneumoniae in invasive infections

PURPOSE

To detect the presence of autolysin and pneumolysin genes among Streptococcus pneumoniae strains isolated from different disease entities among Indian patients. The study also attempted to determine antimicrobial susceptibility of the isolates.

MATERIALS AND METHODS

A total of 24 S. pneumoniae isolates were checked for the presence of lytA gene coding for autolysin and ply gene coding for pneumolysin using polymerase chain reaction (PCR). All the isolates were subjected to susceptibility testing by disc diffusion method for 10 different therapeutically relevant antibiotics. Minimum inhibition concentration (MIC) was determined using broth dilution method for ampicillin, penicillin and ciprofloxacin.

RESULTS

Eleven isolates from ocular infections and 13 isolates from different invasive diseases showed susceptibility to most of the antibiotics tested except chloramphenicol and ciprofloxacin. Fifty percentage of the isolates showed resistance to chloramphenicol and ciprofloxacin. A moderate level of resistance of 18% was noted for cefepime and ceftriaxone. Only 6% of resistance was observed for amoxicillin and ceftazidime. MIC levels ranged from 0.015 to 1 microg/mL for ampicillin and only one isolate had an MIC of 1 microg/mL. The MIC levels for penicillin ranged from 0.062 to 4 microg/mL, wherein nine isolates showed high levels of MICs ranging from 2 to 4 microg/mL. Six isolates had a very high resistance levels for ciprofloxacin with MIC ranging from 32-128 microg/mL. The presence of lytA was observed in 23 out of 24 isolates tested whereas only 17 isolates were positive for pneumolysin. Four ocular isolates and one isolate from ear infection were negative for pneumolysin.

CONCLUSION

Emerging resistance observed for cefepime and ceftriaxone might be due their increased and frequent usage nowadays. Presence of pneumolysin appears to be more critical for pathogenesis of invasive infections than the ocular infections. However, presence of lytA gene in all the isolates signifies that irrespective of site of isolation, kind of infection caused, autolysin is an obligate necessity for this organism.

In vivo autofluorescence characteristics of pre- and post-treated oral submucous fibrosis: a pilot study

AIMS AND OBJECTIVES

To compare the autofluorescence spectra of oral submucous fibrosis (OSF) with normal mucosa, the autofluorescence spectra of OSF before and after treatment with intralesional dexamethasone and hyaluronidase, the clinical improvement following treatment with the changes in autofluorescence spectra and to prove that autofluorescence spectroscopy is a good method for diagnosis and assessment of treatment effectiveness in OSF.

MATERIALS AND METHODS

The study was conducted at the Department of Oral Medicine and Radiology, Tamilnadu Government Dental College and Hospital, Chennai and Division of Medical Physics and Lasers, Department of Physics, Anna University, Chennai in 20 patients seeking medical management for symptomatic OSF and 20 patients who had dental caries only without any oral mucosal diseases and oral habits were used as normal controls. Their ages ranged from 20 to 40 years, including both male and female. In vivo fluorescence emission spectra were obtained using a handheld optical fiber probe attached to a Fluoromax-2 spectrofluorometer.

RESULTS

The fluorescence spectrum of OSF had an intense fluorescence emission at 385 nm with a secondary emission peak at 440 nm compared with that of the normal oral mucosa. The average fluorescence spectrum of the post treated OSF mucosa had a lesser intensity around 385 nm and a higher intensity around 440 nm than that of the pre treated OSF mucosa, thereby mimicking the normal oral mucosa. All the three clinical parameters (maximal mouth opening, tongue protrusion and the severity of burning sensation) showed a high statistical significance, with P < 0.001, as in the case of classification of pre treated OSF mucosa from the post treated OSF mucosa using the autofluorescence technique.

CONCLUSION

The change in the fluorescence emission spectrum for both normal and OSF mucosa before and after treatment can be explained by analyzing the changes in the fluorescence intensity of the endogenous fluorophores.

Phenotypic and genotypic assays for detecting the prevalence of metallo-β-lactamases in clinical isolates of Acinetobacter baumannii from a South Indian tertiary care hospital

Nosocomial infections caused byAcinetobacter baumanniioften prove difficult to treat owing to their multiple drug resistance. Carbapenems play a pivotal role in the management of severeAcinetobacterinfections. However, reports of carbapenem resistance have been increasing alarmingly due to production of a variety of carbapenemases including metallo-β-lactamases (MBLs). This study investigated by both phenotypic and genotypic assays the prevalence of MBLs in a total of 55A. baumanniistrains isolated from a South Indian tertiary care hospital. Random amplified polymorphic DNA (RAPD) genotyping and antimicrobial susceptibility testing for nine clinically relevant antibiotics was done for characterization of isolates. Phenotypic expression of MBLs was examined by a simple double disc synergy (DDS) test, and the presence of the most frequent MBL coding genes,blaIMP1andblaVIM2, was checked by PCR. RAPD analysis generated six clusters of isolates and there was very little correlation between RAPD clusters and resistant profiles. Most of the isolates showed complete or high resistance to imipenem (100 %), meropenem (89 %), amikacin (80 %), cefotaxime (89 %) and ciprofloxacin (72 %). In addition, 44 % of isolates showed a high MIC level (≥16 μg ml−1) for meropenem. Thirty-nine isolates (70.9 %) were positive for MBL production by the DDS test whileblaIMP1gene amplification was seen only in 23 isolates (42 %). Interestingly, none of the isolates showed amplification ofblaVIM2. Further investigations on DDS-positive/PCR-negative isolates by spectrophotometric assay showed MBL activity in most of the isolates, suggesting involvement of other genes. The high incidence of isolates possessing MBL activity in the present study represents an emerging threat of complete resistance to carbapenems amongAcinetobacterspp. in India.

Correlation between biofilm production and multiple drug resistance in imipenem resistant clinical isolates of Acinetobacter baumannii

PURPOSE

To study the qualitative and quantitative methods for the investigation of biofilm formation and to examine the correlation between biofilm and antibiotic resistance among the clinical isolates of Acinetobacter baumannii . We also verified the association between biofilm and presence of extended spectrum beta-lactamases, particularly, bla PER-1 .

METHODS

A total of 55 isolates were subjected to susceptibility testing by disc diffusion method for 13 clinically relevant antibiotics. Screening for biofilm production was done by both qualitative and quantitative methods through tube and microtitre plate assay respectively. The presence of bla PER-1 was checked by PCR.

RESULTS

A. baumannii isolates showed very high resistance (>75%) to imipenem, cephotaxime, amikacin and ciprofloxacin. Only cefoperazone, netillin and norfloxacin were found to be effective agents. Results of microtitre and tube methods were concordant with 34 isolates (62%) showing biofilm formation. Resistance to four antibiotics such as amikacin (82% vs. 17.6%, P < 0.001), cephotaxime (88% vs. 11%, P P < 0.001), ciprofloxacin (70% vs. 29%, P =0.005) and aztreonam (38% vs. 11%, P =0.039) was comparatively higher among biofilm producers than non-biofilm producers. Microtitre assay additionally detected 14 weakly adherent isolates. Only 11 isolates had bla PER-1 gene and among these two were strong biofilm producers, while remaining were weakly adherent isolates.

CONCLUSION

Microtitre plate method was found to be a more sensitive method for biofilm detection. This study demonstrates a high propensity among the clinical isolates of A. baumannii to form biofilm and a significant association of biofilms with multiple drug resistance. Presence of bla PER-1 appears to be more critical for cell adherence than for biofilm formation.

Inhibition of MAP kinases and down regulation of TNF-alpha, IL-beta and COX-2 genes by the crude extracts from marine bacteria

Crude ethyl acetate extracts from marine bacterial isolates Staphylococcus arlettae KP2 (GenBank accession No. EU594442) and Planococcus maritimus KP8 (GenBank accession No. EU594443) isolated from Andaman seas were studied for their anti-inflammatory effect by lymphocyte proliferation assay (LPA) employing peripheral blood mononuclear cells (PBMCs). The crude extracts from both the bacteria down regulated the synthesis of inflammatory mediators such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and cyclooxygenase-2 (COX-2), besides markedly inhibiting p38 mitogen activated protein (MAP) kinase. These results suggest that the crude ethyl acetate extracts from both the isolates do contain compounds capable of inhibiting inflammation in mitogen induced PBMC and efforts to score potential bioactive molecules from these extracts may prove to be a promising preposition.

Cloning, expression, and sequence analysis of diaminopropionate ammonia lyase gene from a nonvirulent Salmonella typhimurium PU011

BACKGROUND

Seeds ofLathyrus sativus, a legume plant, contain 3-oxalyl and 2,3-dioxalyl DAP (O-DAP), neurotoxins which when consumed causes Neurolathyrism or Osteolathyrism, in humans, affecting nervous system and bone formation respectively. Some microorganisms viz virulent and non-virulentSalmonella typhimurium, Salmonella typhi and Pseudomonad have been shown to detoxifyL-alpha,beta-diaminopropionate (DAP), the immediate precursor of O-DAP.

RESULT

The gene coding for diaminopropionate ammonia lyase (DAPAL) which detoxifies DAP was cloned from nonvirulentS. typhimurium PU011 into Escherichia coli DH5alpha and the nucleotides sequenced (1212 bp). Whereas the specific enzyme activity of DAPAL obtained from recombinantE. coli PU018 was 0.346 U/mg, the specific activity of the enzyme from nonvirulentS. typhimurium PU011 was 0.351 U/mg. The DAPAL corresponding to 43 kDa protein was found both in nonvirulentS. typhimurium PU011 andE. coli PU018. The Km value was found to be 0.740 mM and 0.680 mM forS. typhimurium PU011 and 0.741 mM and 0.683 mM forE. coli PU018 when grown in minimal medium (MM+DAP) andL. sativus seed extracts respectively, indicating that both of them were capable of utilizing the neurotoxins present inL. sativus seeds. The biomass, enzyme production and the effect of pH and temperature on DAPAL enzyme activity from both non-virulentS. typhimurium PU011 andE. coli PU018 were found to be similar.

CONCLUSION

The recombinantE. coli PU018 as well as non-virulentS. typhimurium PU011 are as good as pathogenicS. typhimurium in detoxifying DAP, the immediate precursor of O-DAP present inL. sativus seeds.

Synthesis, characterization and in vitro biological activity studies of Cu–M (M=Cu2+, Co2+, Ni2+, Mn2+, Zn2+) bimetallic complexes

Six new bimetallic complexes of the type CuCu, CuCo, CuNi, CuZn and CuMn were prepared. The structures of these complexes and the ligand have been proposed on the basis of FAB mass, elemental analysis, UV-vis, IR, EPR and CV studies. All the complexes completely cleave pBS (SK-) DNA at a concentration of 10 microM; however, even at lower concentrations of 2 microM and 0.1 microM, the complexes (I and Ia) showed partial cleavage. The results of the fluorescence binding studies of the metal complexes with CT-DNA showed that the presence of aliphatic ligands added additional binding effects including electrostatic, hydrogen binding and vander Waals interactions. Complexes (I, Ia) showed 50% inhibition of COX-1 and COX-2 activities at as low a concentration as 12.5 microM, 13.5 microM, 14 microM and 14.5 microM. Inhibition assay of top I and top II by different complexes in mutant yeast strains (JN394, JN394 t(-1) and JN394 t(2-5)) with all the complexes showed significant inhibition of topoisomerase at 5 microM concentration. Complexes I and Ia exhibited good anti-microbial activities against all human pathogens tested except Klebsiella pneumoniae. The following studies showed that among the synthesized bimetallic complexes, complexes I and Ia seem to be promising candidates possessing DNA cleavage activities besides anti-microbial and anti-inflammatory properties to serve as chemical nucleases and chemotherapeutic agents.

Mucormycosis presenting as palatal perforation

Mucormycosis is an opportunistic fungal infection that is caused by normally saprobic organism of the class Zygomycetes. The main form of mucormycosis are pulmonary and rhinocerebral. Rhinocerebral mycormycosis typically starts in the maxillary antrum, particularly in poorly controlled diabetics. Invasion of surrounding tissue can cause necrotizing ulceration of palate with a blackish slough and exposure of bone. A case of mucormycosis presenting as palatal performation is discussed in this article.