Abstract 3379: Comprehensive circulating tumor DNA and CTC profiling of treatment naïve early-stage head and neck cancer patients reveals early signature of disease progression

Comprehensive CtDNA and CTC profiling of treatment naïve early-stage head and neck cancer patients reveals early signatures of disease progressionBackground: We performed comprehensive ctDNA analysis on early-stage HNC patients in a pilot study to determine the mutational landscape in HNC patients with a known tobacco history. Methods: We analysed ctDNA of 18 early-stage HNC patients for genomic landscapes using the illumina NextSeq 2000 NGS. A custom-designed OncoIndex gene panel was used for the hybrid capture target-enrichment of critical cancer genes. Panel was designed to detect cancer targeting exonic sequence of 600 genes reporting SNVs and indels along fusions and copy number amplification. The gene panel detected genome-wide signatures including bTMB, MSI (microsatellite instability), HRD (homologous recombination deficiency) prediction and calculate cfDNA tumor fraction. Results: 80 % patients showed presence of at least one CTC in peripheral blood, possibly indicating the progressive disease at the time of presentation. Comprehensive genomic profile obtained from plasma cfDNA of early-stage HNC cancer patients predominantly had low bTMB and MSI Scores (99 % patients). However, HRD and LOH matrix was high for 60 % patients indicating highly dysregulated DNA repair activities. Concurring to these observations, 98 % patients had mutations in key tumor suppressor and DNA damage response (DDR) genes possibly resulting in their loss of function. Besides DNA damage pathway, 60% patients harboured alterations in RTK genes including FGFR, EGFR and PDEGFR family and 32% patients showed activating mutations in Erk1 and its upstream regulators. MSH2 was the most prominently mutated gene (37%) followed by FGFR (32%). Surprisingly, unlike HPV positive advanced HNC cases, TP53 mutations were not detected in any patient, though alterations in TS genes were most prevalent in the study population. 51% alterations resulted into truncated proteins possibly impairing their functions, while 42% alterations were point mutations, 6 % were frameshift and 1 % indels. Presence of mutations in BRAF, PDGFR, FGFR and KIT genes suggested for the potential therapy resistance. Tumor fraction representing ctDNA showed elevated range from 20 % to 45 % with a corresponding ploidy between 2 to 4. Conclusions: Comprehensive ctDNA profile showed major gene alterations in TS and DDR response pathway genes besides mutations in proliferative signaling members. TP53 mutation was not detected, although critical tumor suppressor and DDR genes were predominantly mutated, suggesting for a unique mutation pattern associated with early-stage HNC due to tobacco etiology. Our results suggest that comprehensive ctDNA analysis along CTC profiling can predict the disease progression beforehand and may offer new treatment options to early-stage HNC patients.

Citation Format: Gowhar Shafi, Atul Bharde, Fauzul Moubeen, Kanchan Hariramani, Alain D’Souza, Trupti Kad, Bhagwat Jadhav, Sangita Prajapati, Aditi Rani, Madhura Basavalingegowda, Mohan Uttarwar, Gourishankar Aland, Sreeja Jayant, Aravindan Vasudevan, Pankaj Chaturvedi, Jayant Khandare. Comprehensive circulating tumor DNA and CTC profiling of treatment naïve early-stage head and neck cancer patients reveals early signature of disease progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3379.

Accelerated Epigenetic Aging Mediates the Association between Vitamin D Levels and Knee Pain in Community-Dwelling Individuals

OBJECTIVES

To examine the relationship between Vitamin D status and pain intensity and disability in individuals with and without knee pain, and to examine the role of epigenetics in this relationship.

DESIGN

Cross-sectional analysis of data from the UPLOAD-2 study (Understanding Pain and Limitations in OsteoArthritic Disease-2).

PARTICIPANTS

189 individuals aged 45-65 years and older.

MEASUREMENTS

Serum Vitamin D levels, pain related interference and characteristic pain intensity measures, and the epigenetic clock GrimAge derived from blood analyses.

RESULTS

Lower Vitamin D was associated with advanced epigenetic aging (AgeAccelGrim), greater pain and disability and that (AgeAccelGrim) mediated the relationship between Vitamin D status and self-reported pain (ab = -0.0799; CI [-0.1492, -0.0237]) and disability (ab = -0.0669; CI [-0.1365, -0.0149]) outcomes.

CONCLUSION

These data support the notion that lifestyle factors such as nutrition status play a key role in aging process, as well as the development and maintenance of age-related diseases such as pain. Modifying nutrition status could help promote healthy aging and reduce pain.

Effect of genotype, seed development stages, and processing treatments on Bowman-Birk inhibitor in soybean and its level in commercial soy products

Bowman-Birk inhibitor (BBI) is a protease inhibitor that affects protein digestibility; however, it is increasingly being recognised as anutraceutical and cosmeceutical molecule. In the present study, BBI concentration during soybean seed development, its loss during processing treatments, and the level in commercial soy products were determined. Significant differences for BBI concentration were observed across the genotypes and seed development stages. Genotype × seed development stage interaction was also found to be significant (P<0.05) for BBI concentration. Boiling, autoclaving, microwave irradiation, and sprouting resulted in significant (P<0.05) loss of BBI. Minimum loss was observed in sprouting, while autoclaving for 5 min completely deactivated BBI. Microwave irradiation of the soaked seeds resulted in higher BBI loss than of dry seeds. Among the commercial soy products, BBI concentration was high in soy flour brands, minuscule in ready-to-cook miso soup and undetectable in extruded soy products and roasted soy nuts.

Association of Childhood Attention Deficit Hyperactivity Disorder Symptoms with Academic and Psychopathological Outcomes in Indian College Students: a Retrospective Survey

OBJECTIVE

To survey the prevalence of retrospectively recalled clinically significant symptoms of attention deficit hyperactivity disorder (ADHD) in childhood and determine the association of ADHD symptoms in childhood with current academic achievement and psychopathological outcomes among college students in the state of Kerala, India.

METHODS

A self-administered questionnaire was distributed to 5784 students from 58 colleges selected by cluster random sampling. The Barkley Adult ADHD Rating Scale-IV was used for recollection of childhood ADHD symptoms; a total score of ≥60 (indicating the 99 percentile) was taken as the cut-off for clinically significant ADHD symptoms in childhood. The Alcohol, Smoking and Substance Involvement Screening Test was used to assess lifetime use of alcohol and tobacco. The Kessler Psychological Distress Scale was used to assess non-specific psychological distress. Lifetime suicidality and exposure to sexual abuse were assessed by asking relevant questions. Students who recalled having clinically significant ADHD symptoms in childhood were compared with those who did not.

RESULTS

Of 5784 students, 639 (11.5%) did not complete the questionnaire. Of the remaining 5145 students, 1750 (34.8%) were men and 3395 (65.2%) were women, with a mean age of 19.4 years. 143 (2.8%) students reported clinically significant ADHD symptoms in childhood. Childhood ADHD symptoms were significantly more common in men and in those living in urban areas. In the bivariate analysis, those with clinically significant ADHD symptoms in childhood had significantly higher odds of poorer academic performance, alcohol use, tobacco use, psychological distress, suicidal thoughts, suicidal attempts, and contact and non-contact sexual abuse, after adjusting for sex and residence.

CONCLUSIONS

Clinical evaluation and appropriate management may be warranted for adults who retrospectively recall clinically significant ADHD symptoms in childhood.

Mirror finger patterns of apparent monozygotic twins and sib pairs with Schizophrenia

BACKGROUND

Although mirror images are noted in some twins, no such reports are available for twins and subjects with schizophrenia.

AIM

The study was to assess the occurrence of mirror image finger patterns in apparent monozygotic twins with schizophrenia. Another objective was to elucidate these characteristics among sib pairs with schizophrenia for comparison with those of the twins.

MATERIALS AND METHODS

Eight apparent monozygotic twin pairs and eight sib pairs with schizophrenia were investigated. The frequency of identical patterns in the right side finger of one twin and the corresponding left side finger of the other twin was assessed, and similarly on other sides. Similar assessment was made in sib pairs with schizophrenia and normal sib pairs.

RESULTS

The left middle finger pattern of one of the twin pair was found to be the mirror image of the right middle finger of the other twin in all the twin pairs studied and so was in seven of the sib pairs with schizophrenia. These mirror images of sib pairs with schizophrenia was more than those of normal sib pairs. This difference was accentuated with significantly more of these patterns in the twins in comparison to those among normal sib pairs. Notably, no difference emerged between the sib pairs with schizophrenia and the twins in any of their finger pairs.

CONCLUSION

Mirror images that are probably due to factors like abnormal genotypes and L- DNA, appear to be promising tools to study the etiology of schizophrenia.

Study of anemia in nondialysis dependent chronic kidney disease with special reference to serum hepcidin

We studied the role of serum hepcidin in anemia of chronic kidney disease (CKD) in a hospital-based cross-sectional study. Serum hepcidin, ferritin, and high-sensitivity C-reactive protein (hsCRP) levels were evaluated in patients of CKD. Hepcidin levels were increased in patients as compared to healthy adults. Hepcidin levels increased as CKD progressed through stage 3-5 (P trend = 0.015) but did not correlate with estimated glomerular filtration rate. Hepcidin correlated positively with ferritin (P < 0.0001) and transferrin saturation (TSAT) (P = 0.0217) and negatively with erythropoietin (EPO) levels (P = 0.0258) but did not correlate with either hsCRP or estimated glomerular filtration rate. Iron status influenced hepcidin levels of patients. Patients were divided according to iron status on the basis of TSAT and serum ferritin levels. We observed that while absolute iron deficiency (transferrin saturation <20%, ferritin <40 ng/ml) is associated with downregulation of hepcidin, hepcidin is elevated in other two categories of CKD patients (P = 0.0039). Iron status of patients also influenced interaction between hepcidin and hemoglobin (Hb). Hepcidin correlated negatively with Hb in patients with sufficient iron status (r = -0.7452, P < 0.0001) but nearly correlated positively with Hb in patients with absolute iron deficiency (r = 0.9428, P = 0.0572). Almost similar association persisted when cutoff value for serum ferritin was raised to 100 ng/ml as per NKF/KDOQI 2006 clinical practice guidelines except that no association was observed in absolute iron deficiency category. Cutoff value for hepcidin for differentiating absolute iron deficiency from other categories in our study population is ≤ 34 ng/ml (area under curve = 0.836, P < 0.0001). In conclusion, serum hepcidin level is increased in nondialysis CKD patients as compared to healthy adults possibly due to associated inflammation and decreased renal clearance. Furthermore, iron status modifies hepcidin level and its association with Hb. Raised hepcidin can predict the need for parenteral iron therapy and need for higher dose of recombinant human EPO to overcome iron-restricted erythropoiesis.

Fusion of axis with third cervical vertebra: a case report

Introduction: Fusion of one or more contiguous vertebral segments is usually the result of embryological failure of normal spinal segmentation. It may be associated with syndromes such as Klippel-Feil. Fused cervical vertebrae (FCV) may also be acquired or pathologic. FCV is generally associated with disease like tuberculosis, other infections, juvenile rheumatoid arthritis and trauma. The commonest site of involvement is C2-C3. In condition of fusion the two vertebrae appear not only structurally as one but also function as one. This anomaly may be asymptomatic; however, it may also manifest in the form of serious clinical features such as myelopathy, limitation of the neck movement, muscular weakness, atrophy or neurological sensory loss.

Case report: We observed the fusion of axis with 3rd cervical vertebra. Body, laminae and spines of C2 and C3 were completely fused on both anterior and posterior aspects, whereas the pedicles and transverse processes were not fused. Foramen transversarium was present on both the vertebrae bilaterally.

Conclusion: This variation is noteworthy to neurosurgeons and radiologists in studying computed tomography (CT) and magnetic resonance imaging (MRI) scans.

Abstract P3-05-05: Targeting tumor re-wiring by triple blockade of mTORC1, ERBB and ER signaling pathways in endocrine resistant breast cancer

AIM To target tumor re-wiring by combined mTORC1 inhibition plus hormonal treatment with or without co-blockade of ERBB signaling in endocrine resistant models of human breast cancer (BC).

BACKGROUND Around 80% of BCs are estrogen receptor positive (ER+). Endocrine therapies target estrogenic stimulation of tumor growth but resistance remains problematic. Several strategies have shown that resistance often depends on the acquisition of enhanced cross-talk between ER and growth-factor pathways, allowing the disease to circumvent the need for steroid hormones. We have previously reported the antiproliferative effects of the combination of everolimus (RAD001-mTORC1 inhibitor) with endocrine therapy in resistance models, but potential routes of escape from treatment via ERBB2/3 signaling were observed. We hypothesised that combined targeting of three signaling pathways, namely ER, ERBB and mTORC1 may provide enhanced anti-tumor activity.

METHODS ER+ BC cell lines (MCF7, SUM44 and HCC1428) adapted to long term estrogen-deprivation (LTED) which model relapse on an aromatase inhibitor, along with their wild-type (wt) cell lines were treated with neratinib, a pan-ERBB tyrosine kinase inhibitor, in combination with RAD001 ± estradiol (E2), tamoxifen or fulvestrant. End points included proliferation, cell signaling, cell cycle and effect on ER-mediated transactivation and recruitment by ChIP.

RESULTS All cell lines showed a concentration-dependent decrease in proliferation in response to RAD001 (IC50 0.6-50nM in absence of E2 and 1-10nM in presence of E2). A wide range of IC50 values (300-1000nM) was observed with neratinib treatment in the presence of E2. However, in the absence of E2, wt cell lines showed IC50 values in excess of 1800nM with hormetic dose response curves, in which lower concentrations induced cell proliferation. In contrast, LTED IC50 values ranged between 400-900nM. Combination of either agent with endocrine therapy caused a concentration dependent decrease in proliferation in all wt cell lines and their LTED derivatives, but the maximum effect was observed when a triple combination of RAD001, neratinib and ER-blockade was used. Expression of pS6 was dramatically suppressed by RAD001 ± neratinib in all cell lines tested, whilst neratinib caused a cell line specific reduction in expression of ERBB family proteins. Upregulation of pAKT was observed in all cell lines following treatment with RAD001, indicating both inhibitors were effectively suppressing their respective targets. Combination of RAD001 with neratinib suppressed the upregulation of pAKT and significantly reduced cell cycle progression. In the absence of E2, RAD001 caused a reduction in ER-mediated transcription and decrease in recruitment of ER and the CREB-binding protein (CBP) to the TFF1 promoter. In contrast, neratinib induced a marked increase in ER-recruitment and concomitant rise in ER-mediated transactivation, which was reduced by the addition of RAD001.

CONCLUSION Targeting tumor re-wiring by triple blockade of ERBB, ER and mTORC1 signaling pathways significantly reduces cell proliferation supporting the potential combination in patients who have relapsed on endocrine therapy and retain a functional ER.

Citation Format: Nikitorowicz-Buniak J, Ribas R, Rani A, Pancholi S, Guest SK, Cutler Jr RE, Lalani A, Dowsett M, Johnston SR, Martin L-A. Targeting tumor re-wiring by triple blockade of mTORC1, ERBB and ER signaling pathways in endocrine resistant breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-05-05.

Antibacterial and antioxidant activity of lichen species Ramalina roesleri

Solvent extracts of Ramalina roesleri Nyl were assayed for antimicrobial and antioxidant activity. Hexane extract was highly active against Staphylococcus aureus and Streptococcus mutans. The 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity of extracts ranged from 29.42% to 87.90%. Atranorin, protolichesterinic acid, usnic acid, 2-hydroxy-4-methoxy-6-propyl benzoic acid, homosekikaic acid, sekikaic acid, benzoic acid, 2,4-dihydroxy-6-propyl and 2,4-dihydroxy-3,6-dimethyl benzoate were isolated from the hexane extract. Maximum DPPH radical scavenging activity was exhibited by sekikaic acid followed by homosekikaic acid.

Duplicated anterior belly of the digastric muscle

During routine dissection of the submental region of a 65-year-old female cadaver, a bilateral supernumerary muscle, medial to the anterior bellies of the digastric muscle, was observed. The accessory muscle bundle was attached proximally to the digastric fossa of the mandible, with an intermediate attachment to the body of hyoid bone and a distal attachment to the medial margin of the lower end of the anterior belly of the digastric muscle and its intermediate tendon on the respective side. These types of bilaterally symmetrical accessory muscles of the submental region may be erroneously identified as an infarcted submental lymph node or a pseudomass on radiological examinations.

Regional hippocampal differences in AKT survival signaling across the lifespan: implications for CA1 vulnerability with aging

Distinct neuronal populations differ by the degree of damage caused from cellular stress. Hippocampal neurons of area CA1 are especially vulnerable to several stressors that increase as age advances. We show here that survival signaling, as measured by activated protein kinase B (AKT), was significantly reduced in the nuclear CA1 region across the lifespan compared with CA3. In agreement with these findings, the pro-apoptotic protein and AKT nuclear substrate, forkhead box O3a transcription factor (FOXO3a), were significantly higher in CA1. Further, regional differences in PH domain and leucine-rich repeat protein phosphatase 1 (PHLPP1), a recently discovered inhibitor of AKT, inversely correlated with nuclear phosphorylated AKT at Ser473. Altogether, our data suggest that regional differences in nuclear levels of activated AKT may contribute to regional differences in hippocampal vulnerability and implicate PHLPP1 as a potential target for therapeutic intervention to improve hippocampal health.

Epidermal growth factor receptor-directed therapy in esophageal cancer

Esophageal adenocarcinoma (EAC) is one of the fastest growing malignancies in the US. The long-term survival of patients with this cancer remains poor; only 25% of patients undergoing surgical excision are alive after 5 years. Multimodal programs that incorporate radiotherapy, chemotherapy and surgery for localized tumors may result in a modest survival advantage. However, significant strides in this disease can result from the inclusion of targeted therapies. The epidermal growth factor receptor (EGFR) family represents one such target and is receiving increasing attention due to the advent of specific inhibitors. Studies conducted by us and others have shown that the overexpression of EGFR family signaling intermediates is common in Barrett's esophagus and EAC. In the latter case, EGFR expression may have prognostic significance. EGFR inhibitors, including oral tyrosine kinase inhibitors and monoclonal antibodies, result in a synergistic antitumor effect with chemotherapeutic agents or with radiotherapy. Therefore, several ongoing studies include EGFR-directed therapy either alone or in combination with chemoradiotherapy for this disease. Our study of gefitinib, oxaliplatin and radiotherapy suggested that gefitinib can be safely incorporated into an oxaliplatin-based chemoradiation program for esophageal cancer, although the clinical activity of this combination is modest. Herein, we review the current literature on this subject.

Isolation, structural elucidation and characterization of impurities in Cefdinir

Three unknown impurities in Cefdinir bulk drug at levels below 0.2% (ranging from 0.05 to 0.2%) have been detected by high performance liquid chromatography (HPLC). These impurities were isolated from crude sample of Cefdinir using preparative HPLC. Based on the spectral data (NMR, IR and MS) the structures of these impurities were characterized as (6R, 7R)-7-[(z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-8-oxo-3-vinyl-5-thia-1-azabicyclo [4.2.0] oct-2-ene-2-carboxylic acid-5-oxide (I). (6R, 7R)-7-[(z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-8-oxo-3-vinyl-5-thia-1-azabi-cyclo [4.2.0] oct-3-ene-2-carboxylic acid (II). (6R, 7R)-7-[(z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-8-oxo-3-methyl-5-thia-1-azabicyclo-[4.2.0]oct-2-ene-2-carboxylic acid (III), respectively. The origin and structural elucidation of all impurities have been discussed.

Simultaneous Ocular and Systemic Cysticercosis and Tuberculosis

Human cysticercosis and tuberculosis are endemic diseases in developing countries. Both these diseases have certain common factors of origin. We would like to present the co-existence of these infections in a 20-year-old female. She was a known case of pulmonary and ocular tuberculosis and she acquired cysticercosis of the eye and brain.

Epidemiologic classification of seizures associated with neurocysticercosis: observations from a sample of seizure disorders in neurologic care in India

AIMS

To determine the etiologic role of neurocysticercosis (NC) in a hospital-based sample of epilepsies divided according to International League Against Epilepsy (ILAE) epidemiological criteria and number of seizures prior to presentation.

METHODS

A sample comprising 1026 consecutive patients with either definite seizures or epilepsy attending a Neurology Outpatient Service was divided into four subgroups: single seizure (n = 314), incident epilepsy (n = 127), prevalent epilepsy (n = 398) and recurrent acute symptomatic seizures (RASS) (n = 175). The etiologic contribution of NC to each of the subgroups was examined with imaging studies.

RESULTS

Neurocysticercosis was diagnosed on imaging studies in 34.6% of patients with seizure disorder of any type, 59.2% of those with a single seizure, 23.7% of those with recurrent seizure disorder, 92.0% of those with RASS, none of cases of incident epilepsy and 2.0% with prevalent epilepsy. A diagnosis of NC was significantly associated with single seizures (P < 0.001).

CONCLUSIONS

Imaging abnormalities consistent with NC are frequently noted in persons presenting with a single seizure in neurologic care in NC-endemic countries like India. The probability of diagnosing NC diminishes with increasing numbers of seizures. Among samples of individuals with recurrent-unprovoked seizures, it is rare for imaging to demonstrate lesions of NC.

Visual performance after interface haemorrhage during laser in situ keratomileusis

AIM

To study the visual performance in eyes with interface haemorrhage during laser assisted in situ keratomileusis (LASIK).

METHODS

Case records of 20 patients, who had bleeding from the limbal vessels in one eye during LASIK (group 1) and uncomplicated surgery in the fellow eye (group 2) were studied. The parameters evaluated were uncorrected visual acuity (UCVA) best corrected visual acuity (BCVA), spherical equivalent of refraction (SEQ), contrast sensitivity, and glare acuity preoperatively and at 1, 3, and 6 months postoperatively.

RESULTS

The mean preoperative SEQ in group 1 and 2 eyes was -5.79 (2.3) D and -5.27 (1.68) D, respectively. The mean decimal UCVA at 6 months after LASIK in group 1 and 2 eyes were 0.6 (0.2) and 1.0 respectively (p<0.001). The mean decimal BCVA at 1 week after LASIK in group 1 and 2 eyes were 0.89 (0.04) and 1.0 respectively (p<0.05). However, all eyes had a BCVA of 6/6 at 1, 3, and 6 months after LASIK. The mean contrast sensitivity values preoperatively in group 1 and 2 eyes were 161.3 (8.7) and 172 (68.2) respectively. There was a significant decrease in group 1 at 6 months (102 (60.5) (p<0.01)) compared to group 2. The decimal glare acuity preoperatively in group 1 and 2 eyes was 0.95 (0.11) and 0.89 (0.12), respectively. It decreased significantly in group 1 (0.7) (0.1 (p<0.01)) compared to group 2 at the 6 month follow up.

CONCLUSION

Occurrence of intraoperative interface haemorrhage may affect the visual performance following LASIK surgery.

Posterior corneal topographic changes after partial flap during laser in situ keratomileusis

AIM

To study the posterior corneal topographic changes in eyes with partial flaps during laser assisted in situ keratomileusis (LASIK).

METHODS

Case records of 16 patients, who had partial flap in one eye during LASIK (group 1) and uncomplicated surgery in the other eye (group 2), were studied. Following occurrence of partial flap intraoperatively, laser ablation was abandoned in all the eyes. A 160/180 micro m flap was attempted during the initial procedure using the Hansatome microkeratome (Bausch & Lomb Surgicals, Munich, Germany). LASIK surgery in all cases was performed using a 180 micro m plate, at the mean interval of 4.16 (SD 1.5) months following the initial procedure. None of the eyes had intraoperative complication during LASIK. Relative posterior corneal surface elevation above the best fit sphere (BFS) before the initial procedure, before, and after LASIK were compared using the Orbscan slit scanning corneal topography/pachymetry system.

RESULTS

Posterior corneal elevation was comparable in the two groups, both preoperatively (group 1; 16.4 (4.8) micro m, group 2; 16.1 (4.8) micro m) and after final surgery (group 1; 57.2 (15.6) micro m, group 2; 54.3 (13.1) micro m). In group 1 after occurrence of partial flap, the posterior corneal elevation was 16.9 (4.4) micro m, and this increase was not significant statistically (p=0.4). On multiple linear regression analysis, residual bed thickness (p<0.001) was independently the significant determinant of final posterior corneal elevation in both groups.

CONCLUSION

The inadvertent occurrence of partial flap during LASIK procedure does not contribute to the increase in posterior corneal elevation.

Association of pyrogenic exotoxin genes with pharyngitis and rheumatic fever/rheumatic heart disease among Indian isolates of Streptococcus pyogenes

AIM

To monitor the presence of various pyrogenic exotoxin genes in strains of Streptococcus pyogenes isolated in India.

METHODS & RESULTS

Isolates recovered from pharyngitis (52) and rheumatic fever (RF)/ rheumatic heart disease (RHD) (8) patients were analysed for the presence of toxin genes, speA, speB and speF, by PCR. The specificity of the products was confirmed by restriction enzyme digestion and Southern hybridization. Among the 60 isolates studied, the incidence of speA, speB and speF were 5(8.3%), 56(93.3%) and 53(88.3%), respectively. The expression of these genes was established in representative isolates by RT-PCR.

CONCLUSIONS

Comparative analysis of frequency of the speA, speB and speF genes, among pharyngitis and RF/RHD associated isolates, showed higher incidence in RF/RHD (25%, 100%,100%) as compared to pharyngitis patients (5.8%, 92.3%, 86.5%), respectively. SIGNIFICANCE OF STUDY: The presence of the speA gene, which is usually associated with scarlet fever or toxic shock-like syndrome, within few Indian isolates may be indicative of new virulent strains circulating within the Indian community. High distribution of toxin genes among RF/RHD compared to pharyngitis isolates indicate their possible role in increased virulence.

Use of bovine xenograft in reconstruction of traumatic anterior cranial fossa bone defects involving the frontal sinus

Four patients underwent reconstruction of anterior cranial fossa of skull defects between November 1997 and January 1998. All of them had traumatic anterior cranial fossa defect and were reconstructed with lyophilised bovine cortical bone graft. There was no cerebrospinal fluid leakage, meningitis, extradural abscess or other infections. This study demonstrates that the use of bovine bone graft in the reconstruction of anterior base defects is safe.