Concurrent and sequential initiation of ovarian function suppression with chemotherapy in premenopausal women with endocrine-responsive early breast cancer: an exploratory analysis of TEXT and SOFT.

BACKGROUND: Recent breast cancer treatment guidelines recommend that higher-risk premenopausal patients should receive ovarian function suppression (OFS) as part of adjuvant endocrine therapy. If chemotherapy is also given, it is uncertain whether to select concurrent or sequential OFS initiation. DESIGN AND METHODS: We analyzed 1872 patients enrolled in the randomized phase III TEXT and SOFT trials who received adjuvant chemotherapy for hormone receptor-positive, HER2-negative breast cancer and upon randomization to an OFS-containing adjuvant endocrine therapy, initiated gonadotropin-releasing-hormone-agonist triptorelin. Breast cancer-free interval (BCFI) was compared between patients who received OFS concurrently with chemotherapy in TEXT (n = 1242) versus sequentially post-chemotherapy in SOFT (n = 630). Because timing of trial enrollment relative to adjuvant chemotherapy differed, we implemented landmark analysis re-defining BCFI beginning 1 year after final dose of chemotherapy (median, 15.5 and 8.1 months from enrollment to landmark in TEXT and SOFT, respectively). As a non-randomized treatment comparison, we implemented comparative-effectiveness propensity score methodology with weighted Cox modeling. RESULTS: Distributions of several clinico-pathologic characteristics differed between groups. Patients who were premenopausal post-chemotherapy in SOFT were younger on average. The median duration of adjuvant chemotherapy was 18 weeks in both groups. There were 231 (12%) BC events after post-landmark median follow-up of about 5 years. Concurrent use of triptorelin with chemotherapy was not associated with a significant difference in post-landmark BCFI compared with sequential triptorelin post-chemotherapy, either in the overall population (HR = 1.11, 95% CI 0.72-1.72; P = 0.72; 4-year BCFI 89% in both groups), or in the subgroup of 692 women <40 years at diagnosis (HR = 1.13, 95% CI 0.69-1.84) who are less likely to develop chemotherapy-induced amenorrhea. CONCLUSION: Based on comparative-effectiveness modeling of TEXT and SOFT after about 5 years median follow-up, with limited statistical power especially for the subgroup <40 years, neither detrimental nor beneficial effect of concurrent administration of OFS with chemotherapy on the efficacy of adjuvant therapy that includes chemotherapy was detected. CLINICALTRIALS.GOV: NCT00066690 and NCT00066703.

Pathological complete response in locally advanced breast cancer: determinants and predictive significance.

BACKGROUND: Neoadjuvant chemotherapy is now the standard approach for most large breast cancers including locally advanced cancers of the breast. The majority of patients respond satisfactorily to chemotherapy with effective downsizing of tumours to consider breast conservation surgery. Pathological complete response (pathCR) is known to be a strong predictor of good outcome; however, many factors are known to influence the extent of response to chemotherapy. It has been observed that smaller the tumour, better is the response achieved in contrast to larger and locally advanced tumours where only one-third may respond well enough to merit breast conservation. Various other clinical, biological and molecular factors are also being evaluated as effective predictors of chemosensitivity. Most of these are either not easily available for all patients in developing countries or are overtly expensive and not applicable for all patients. METHODS: We evaluated the clinical and pathological predictors of response to chemotherapy in 1402 women with locally advanced breast cancer. RESULTS: There was a higher rate of pathCR in smaller tumours, younger women and ER-negative as well as triple negative tumours. The presence of ductal carcinoma in situ (DCIS) and lymphatic and vascular invasion (LVI) were associated with lower pathCR. CONCLUSION: In the absence of ready availability of expensive molecular and genomic assays, clinical parameters and standard histopathological variables can also be useful indicators of response to neoadjuvant chemotherapy. Additionally, they can help identify those who could be eventually conserved or have a better outcome.

Evaluation of glomerular and tubular renal function in neonates with birth asphyxia.

BACKGROUND: Acute kidney injury (AKI) is one of the commonest manifestations of end-organ damage associated with birth asphyxia. OBJECTIVE: To evaluate glomerular and tubular dysfunction in neonates with moderate to severe birth asphyxia. DESIGN: Prospective cohort study. SETTING: Neonatal unit of a teaching hospital. METHODS: Subjects were inborn neonates of ≥34 completed weeks of gestation with an APGAR score <7 at 1 min after birth. Renal function tests including serum electrolytes were measured daily until 96 hrs of life along with urinary output. Fractional excretion of sodium (FeNa), renal failure index (RFI), urinary myoglobin and creatinine clearance (CrCl) were calculated using timed urine collection. Staging of AKI was undertaken using Acute Kidney Injury Network criteria (AKIN). PRIMARY OUTCOME MEASUREMENT: Recovery of glomerular function. RESULTS: A total of 2196 neonates were born during the study period (September 2006 to April 2007), 44 of whom met the inclusion criteria. Data from 36 neonates were available for final analysis. AKI developed in 9·1% (1/11) infants with moderate asphyxia and 56·0% (12/25) infants with severe asphyxia, making a total incidence of 41·7%. AKI persisted in 16·6% neonates at 96 hours of life. Ten neonates (27·7%) had serum creatinine levels >1·5 mg/dl. In neonates with AKI, tubular function (Fe Na, RFI, urinary myoglobin) was significantly deranged until 72-96 hrs of life. One infant died and one who was critically ill was discharged against medical advice; both had AKI. CONCLUSION: It is feasible to use AKIN staging for evaluating AKI in neonates with birth asphyxia.

Can We Avoid Axillary Lymph Node Dissection (ALND) in Patients with 1-2 Positive Sentinel/Low Axillary Lymph Nodes (SLN/LAS+) in the Indian Setting?

The ACOSOG Z0011 study, heralded as a "practice changing" trial, suggested that women with T1-2 breast cancer with 1-2 SLN+, undergoing breast conservation therapy, need not be offered further ALND. However, whether these results are applicable to all women in the Indian setting, it remains debatable. A retrospective audit of all cN0 operated from 2013 to 2018 was conducted. We analyzed the percentage of additional LN positive (LN+) in the ALND group and compared it to the ACOZOG Z11 trial. Of the 2350 cN0 with EBC who underwent LAS, 687 (29%) had positive lymph nodes on final histopathology. Five hundred ninety-seven (86.9%) patients had 1-2 LN+, 40 (5.8%) patients had 3 LN+, and 50 (7.3%) had 4 or more nodes positive. Demographic features in the ACOSOG Z11 are different from those in our study, looking at ACOZOG Z11 versus our cohort-median pT 1.7 cm versus 3 cm, 45% micrometastasis versus 99.16% macrometastasis, and 28-30% grade 3 tumors versus 73.7%. In our cohort 31.82% of the 1-2 LN positive had additional LN+ on ALND. Keeping in mind the difference in clinicopathological features between our cohort and that of ACOZOG Z0011 and that 31.82% of women had additional LN+ on ALND, it may not be appropriate to apply the results of the ACOSOG Z0011 trial directly to our general population. Possibly, only a select subset of patients who match the trial population of the ACOSOG Z11 could be offered observation of the axilla and validated nomograms can be used to identify high-risk patients.

Microwave synthesis and antifungal evaluations of some chalcones and their derived diaryl-cyclohexenones.

Microwave irradiation (MWI) of acetophenones and substituted benzaldehydes in water resulted in a "green-chemistry" procedure for the preparation of chalcones (1-14), through base catalyzed Claisen-Schmidt condensation reaction, in good yields. Further 3,5-diaryl-6-carbethoxy-2-cyclohexen-1-ones (1a-14a) were prepared through base catalyzed cyclocondensation of above chalcones with ethylacetoacetate using MWI as the energy source and silica as support. Out of fourteen cyclohexenones, ten (1a, 4a, 5a, 6a, 7a, 9a, 10a, 11a, 12a and 13a) are reported for the first time in literature. The synthesized compounds were characterized using various spectroscopic techniques, viz. ((1)H NMR and IR) and screened for their antifungal activity in vitro against Sclerotium rolfsii and Rhizoctonia solani by poisoned food technique. The compounds tested were found to be active against R. solani whereas against S. rolfsii, moderate activity was observed, as evident from LC(50) values. The most potent compounds against R. solani were 1-(4-Fluoro-phenyl)-3-phenyl-propenone (13) and 1,3-Diphenyl-propenone (14) having LC(50) values of 2.36 and 2.49 mg L(- 1) respectively (LC(50) of Hexaconazole = 1.12 mg L(- 1)) and against S. rolfsii 3-(4-Fluoro-phenyl)-5-(3-nitro-phenyl)-6-carbethoxy-2-cyclohexen-1-one (12a) was most active having LC(50) value of 285 mg L(- 1)compared to Hexaconazole (LC(50) = 1.27 mg L(- 1)).

Novel therapeutic strategies targeting telomere maintenance mechanisms in high-risk neuroblastoma.

The majority of high-risk neuroblastomas can be divided into three distinct molecular subgroups defined by the presence of MYCN amplification, upstream TERT rearrangements or alternative lengthening of telomeres (ALT). The common defining feature of all three subgroups is altered telomere maintenance; MYCN amplification and upstream TERT rearrangements drive high levels of telomerase expression whereas ALT is a telomerase independent telomere maintenance mechanism. As all three telomere maintenance mechanisms are independently associated with poor outcomes, the development of strategies to selectively target either telomerase expressing or ALT cells holds great promise as a therapeutic approach that is applicable to the majority of children with aggressive disease.Here we summarise the biology of telomere maintenance and the molecular drivers of aggressive neuroblastoma before describing the most promising therapeutic strategies to target both telomerase expressing and ALT cancers. For telomerase-expressing neuroblastoma the most promising targeted agent to date is 6-thio-2'-deoxyguanosine, however clinical development of this agent is required. In osteosarcoma cell lines with ALT, selective sensitivity to ATR inhibition has been reported. However, we present data showing that in fact ALT neuroblastoma cells are more resistant to the clinical ATR inhibitor AZD6738 compared to other neuroblastoma subtypes. More recently a number of additional candidate compounds have been shown to show selectivity for ALT cancers, such as Tetra-Pt (bpy), a compound targeting the telomeric G-quadruplex and pifithrin-α, a putative p53 inhibitor. Further pre-clinical evaluation of these compounds in neuroblastoma models is warranted.In summary, telomere maintenance targeting strategies offer a significant opportunity to develop effective new therapies, applicable to a large proportion of children with high-risk neuroblastoma. In parallel to clinical development, more pre-clinical research specifically for neuroblastoma is urgently needed, if we are to improve survival for this common poor outcome tumour of childhood.

Differential expression of Aspergillus fumigatus protein in response to treatment with a novel antifungal compound, diethyl 4-(4-methoxyphenyl)-2,6-dimethyl-1,4-dihydropyridin-3,5-dicarboxylate.

A dihydropyridine derivative, diethyl 4-(4-methoxyphenyl)-2,6-dimethyl-1,4-dihydropyridin-3,5-dicarboxylate (2e), having potent antifungal activity against pathogenic species of Aspergillus was investigated for its possible molecular mechanism of action. The SDS-PAGE coupled with nano-high-performance liquid chromatography-tandem mass spectrometry was used directly to assess both absolute abundance and differential expression of proteins in the secretory phases of Aspergillus fumigatus under the influence of 2e. It was observed that the compound inhibited the expression of two proteins of 60.99 and 79.77 kDa. Both of these secretory proteins that were inhibited by 2e, were analysed further by matrix assisted laser desorption ionization time-of-flight mass spectrometry. The 60.99- and 79.77-kDa proteins were identified as probable retroelement pol polyprotein and elongation factor G respectively. These targeted proteins could be the products of potentially virulence-related genes of A. fumigatus which may unravel the mode of action of 2e and pathobiology of A. fumigatus.

Low axillary sampling in clinically node-negative operable breast cancer.

BACKGROUND: Targeted sentinel node biopsy has been extensively validated. It has been incorporated into standard guidelines for axillary prediction in women with clinically node-negative operable breast cancer. However, the high cost of the gamma probe and the need for radiocolloid have limited its widespread acceptance in developing countries. We aimed to validate low axillary sampling as a reliable alternative method to sentinel node biopsy in a developing country. METHODS: An anatomically guided low axillary sampling removes the lower level I axillary fat with lymph nodes and the method was validated by completing axillary clearance in all women. RESULTS: Three hundred fifty-five women with clinically node-negative operable breast cancer underwent validation of low axillary sampling, with lymph nodes identified in all of them. The median number of nodes identified in low axillary sampling was 5 with overall node-positivity of 32.1% (114 of 355). Ten of these 114 patients were wrongly identified as node-negative by the sampled lymph nodes, i.e. a false-negative rate of 8.8%. Further exploratory analysis showed that 6-node low axillary sampling gave an excellent false-negative rate of 1.5% with 95% sensitivity, which was comparable with the highly targeted sentinel node biopsy technique. CONCLUSIONS: With an overall false-negative rate of 8.8% with 5-node low axillary sampling, and even better false-negative rate of 1.5% with 6-node low axillary sampling, axillary sampling is a low-cost technology, which is a reliable alternative to sentinel node biopsy for axillary nodal prediction in clinically node-negative breast cancer.

Drug use pattern in children at a teaching hospital.

This study aimed to evaluate drug utilization in pediatric out-patient department of a tertiary care teaching hospital. The patient and drug information of 254 patients was analyzed for WHO recommended prescribing indicators. The average number of drugs per prescription was 2.31 and 45% of medicines were prescribed from National List of Essential Medicines. The use of injectibles was low (1.18%) while an antibiotic was prescribed in 29.1%. Only 5.8% medicines were prescribed by generic name. Interventions are required to improve prescribing by generic name so as to further rationalize drug use in pediatric population.

Targeting protein acetylation for improving cancer therapy.

Acetylation is one of the most important post-translational modification of proteins determining the structure, function and intracellular localization that plays an important role in the signal transduction pathways related to diverse cell functions, both during unstimulated and stress conditions. Protein acetylation in cells is regulated by a co-ordinated action of histone acetyl transferases (HAT) and histone deacetylases(HDAC) that ensures the maintenance of homeostasis and execution of activities related to damage response viz. DNA repair, cell cycle delay, apoptosis and senescence. Since inhibition of histone deacetylation, stalls the progress of many nuclear events including proliferation and damage response events on the one hand and the levels of deacetylases are elevated in many tumours on the other. Histone deacetylase has been among the targets for the development of anticancer drugs and adjuvant. The recent observation showing acetylation of proteins by calreticulin (an endoplasmic reticulum resident protein) with a high efficiency when polyphenolic acetates are the acetyl group donating molecules and acetyl CoA as weak substrate extends the realm of protein acetylation beyond HAT/HDAC combination. Elucidation of the relative roles of HAT/HDAC mediated acetylation viz. a calreticulin mediated acetylation in cell function under a variety of stress conditions would hold key to the design of drugs targeting protein acetylation system.

Predicting loco-regional recurrence risk in T1, T2 breast cancer with 1-3 positive axillary nodes postmastectomy: Development of a predictive nomogram.

BACKGROUND: Role of postmastectomy radiotherapy (PMRT) in early breast cancer with 1-3 positive axillary nodes is still controversial. Hence, there is a need to identify subgroup of patients who have sufficiently high risk of disease recurrence to benefit from PMRT. AIM: The aim is to evaluate clinical outcomes of patients postmastectomy having pathological T1-T2 tumors with 1-3 positive axillary lymph nodes (LNs) treated with adjuvant systemic therapy and develop a predictive nomogram. MATERIALS AND METHODS: Data collected retrospectively from eligible patients from 2005 to 2011. Kaplan-Meier survival analysis was used for all time-to-event analysis. Various known clinical and pathological risk factors were correlated with outcome using uni- and multi-variable analysis in SPSS version 21. All comparisons were two-tailed and P < 0.05 were considered statistically significant. The nomogram to predict the risk of loco-regional control (LRC) was developed using least absolute shrinkage and selection operator shrinkage model in hdnom.io software. RESULTS: 38/242 (15.7%) patients had recurrent disease at loco-regional (10 patients), distant sites (22 patients) and simultaneous loco-regional and distant sites (6 patients) at a median follow-up 59.5 (range 4-133) months. Five years estimate of LRC, distant disease-free survival (DFS), DFS, cause-specific survival and overall survival was 87.8%, 85.4%, 84.2%, 93.1%, and 91.5%, respectively. Pathological tumor size, margin status, LN ratio as continuous variables and grade and triple negative breast cancer status as categorical variables were the risk factors included in the model for building nomogram. CONCLUSION: The nomogram developed based on institutional data can be a valuable tool in guiding adjuvant PMRT depending on the risk of 5 years loco-regional recurrence.

Central obesity increases risk of breast cancer irrespective of menopausal and hormonal receptor status in women of South Asian Ethnicity.

BACKGROUND: Current evidence suggests that the relationship between obesity and breast cancer (BC) risk may vary between ethnic groups. METHODS: A total of 1633 BC cases and 1504 controls were enrolled in hospital-based case-control study in Mumbai, India, from 2009 to 2013. Along with detailed questionnaire, we collected anthropometric measurements on all participants. We used unconditional logistic regression models to estimate odds ratios (ORs) and 95% confidence interval (CI) for BC risk associated with anthropometry measurements, stratified on tumour subtype and menopausal status. RESULTS: Waist-to-hip ratio (WHR) of ≥0.95 was strongly associated with risk of BC compared to WHR ≤0.84 in both premenopausal (OR = 4.3; 95% CI: 2.9-6.3) and postmenopausal women (OR = 3.4; 95% CI: 2.4-4.8) after adjustment for body mass index (BMI). Premenopausal women with a BMI ≥30 were at lower risk compared to women with normal BMI (OR = 0.5; 95% CI: 0.4-0.8). A similar protective effect was observed in women who were postmenopausal for <10 years (OR = 0.6; 95% CI: 0.4-0.9) but not in women who were postmenopausal for ≥10 years (OR = 1.8; 95% CI: 1.1-3.3). Overweight and obese women (BMI: 25-29.9 and ≥ 30 kg/m(2), respectively) were at increased BC risk irrespective of menopausal status if their WHR ≥0.95. Central obesity (measured in terms of WC and WHR) increased the risk of both premenopausal and postmenopausal BCs irrespective of hormone receptor (HR) status. CONCLUSIONS: Central obesity appears to be a key risk factor for BC irrespective of menopausal or HR status in Indian women with no history of hormone replacement therapy.

Socio-demographic, Epidemiological and Environmental Determinants of Acute Gastroenteritis in Western India.

INTRODUCTION: An outbreak of acute gastroenteritis had occurred in Rajpara village of Bhavnagar district. The objective of this study was to find out the socio-demographic, epidemiological and environmental determinants of this outbreak. METHODS: A case-control study was conducted in Rajpara village among 238 cases of acute gastroenteritis and an equal number of controls in January 2015. Multiple logistic regression was used for identifying the variables independently predicting acute gastroenteritis. RESULTS: Upper socio-economic status, occupation requiring travel outside village, source of drinking water from well of 'new' Rajpara village, change in taste of water, use of chlorine tablets, travel outside village in last week, another family member affected with acute gastroenteritis, using common utensil for hand washing, hand washing before eating, ate food from outside in last week, having sanitary latrine at house, waste disposal in a common dump (instead of at house), waste accumulation around house and flies inside house were significantly associated with occurrence of acute gastroenteritis. On multiple logistic regression, change in taste of water (P<0.001), waste disposal in a common dump (P=0.012), another family member been affected (P<0.001), waste accumulation around house (P<0.001), higher socio-economic status (P=0.002) and eating outside food (P=0.011) made a significant contribution to prediction. CONCLUSIONS: Socio-demographic factors (higher socio-economic status), epidemiological correlates (change in taste of water, another family member been affected with acute gastroenteritis and eating outside food) and environmental determinants (waste disposal in a common dump and waste accumulation around house) significantly determines the occurrence of cases of acute gastroenteritis.

Potential use of a novel lipase from Aspergillus carneus in deacetylation reactions.

A novel lipase from Aspergillus carneus has been used in organic solvents for efficient regioselective and chemoselective deacetylation of the peracetates of polyphenolic aromatic ketones, esters and amides. A reversal of regioselectivity was observed as compared with the results obtained during deacetylation with porcine pancreatic lipase (PPL).

Validation of EORTC quality-of-life questionnaire in Indian women with operable breast cancer.

BACKGROUND: The European Organization for Research and Treatment of Cancer (EORTC) module QLQ-C30 and the breast cancer-specific module BR-23 have been validated worldwide to assess the quality of life (QOL) in women with breast cancer. No such study has been published on Indian women using EORTC questionnaires. METHODS: QOL was assessed in relation to surgery, adjuvant chemotherapy, radiation therapy and hormone therapy in 299 Indian women with operable breast cancer (OBC) at the Breast Unit of Tata Memorial Hospital (TMH), Mumbai, from October 1998 to September 2001. The QLQ-C30 module was used to assess physical health, emotional, cognitive and social functioning, and the BR-23 module to assess breast cancer treatment-related symptoms. Assessment was done at 3 visits: visit 1 (after surgery); visit 2 (during adjuvant therapy) and visit 3 (on completion of adjuvant therapy). RESULTS: Of the 299 women at first visit, 274 (91.6%) completed the visit 2 questionnaire and 239 (80%) completed the visit 3 questionnaire. Only those women who filled the questionnaires at all 3 visits were included as 'valid visits' for analysis (193 of 299; 64.5%). The reliability and validity of the English and translated versions of the questionnaires were tested by Cronbach alpha (0.61-0.96) and item-scale correlation (0.63-0.93). Women with breast conservation treatment had a superior body image as compared to those with mastectomy (p <0.001). Physical, emotional and cognitive functions were not related to the type of surgery. Global QOL, physical, sexual and role functioning were found to deteriorate with chemotherapy (p < or = 0.01). Radiotherapy had only local adverse effects (p < 0.001 ), while hormone therapy had no adverse impact on QOL. CONCLUSION: QLQ-C30 and BR-23 questionnaires can be used reliably to assess QOL in Indian patients. The translated versions were found to be valid for further use in clinical trials on Indian women with breast cancer.

Comparison of referrals for lumbar spine magnetic resonance imaging from physiotherapists, primary care and secondary care: how should referral pathways be optimised?

OBJECTIVE: To compare sensitivity of pathology on imaging between referrals from primary care, physiotherapists, spinal surgeons and other secondary care providers. DESIGN AND SETTING: A retrospective review of 200 consecutive magnetic resonance imaging (MRI) scans of patients' first presentations to radiology for MR lumbar scanning at a tertiary orthopaedic centre. A scan report was defined as positive if there was any evidence of neural compromise. Fisher's exact 2×2 contingency analyses were performed. RESULTS: Eighty-seven (44%) scans were positive and 113 (57%) were negative. Forty-four percent of scans requested by general practitioners (GPs) were reported as positive compared with 57% of scans requested by physiotherapists. Only 40% and 20% of scans requested by specialist spinal surgeons and non-spinal team secondary care providers were positive, respectively. Physiotherapist referrals for MRI lumbar spine scans were significantly more likely to be positive compared with GPs (P=0.05), spinal surgeons (P=0.03) and others (P=0.004). CONCLUSION: When appropriate, referrals via the extended physiotherapy service should be encouraged, rather than referrals directly from GPs. With appropriate training and in the appropriate clinical context, extended physiotherapy services could include inpatients and could accept outpatient referrals from other secondary care providers and not just from GPs; this would improve efficiency and reduce the workload of the radiology department and the spinal surgical unit.

A Rare Case of Richter's Variety of Obstructed Femoral Hernia in a Male.

Femoral hernias are elusive conditions that, despite having life-threatening complications, are often undiagnosed in asymptomatic patients. They are less common than inguinal hernias and occur more frequently in females [Purushotham et al. (2014) J Evol Med Dent Sci 3(05):1160-1163]. In the first place, femoral hernia in a male patient is itself, a very rare clinical presentation, let alone complications like obstruction or strangulation in the second place. Thus, despite the fact that femoral hernias account for only 2-4 % of all groin hernias, their timely and correct diagnosis is vital due to the increased mortality associated with emergency surgery for their complications [Arkoulis et al. (2012) Ox J Med, J Surg Case Rep 2012(6):6]. This, however, is not always easy, where mortality has been found to be tenfold. Here, we present a case of right-sided obstructed femoral hernia of Richter's variety in a male of 52 years of age.

Seroprevalence and comparison of different serological tests for brucellosis detection in small ruminants.

AIM: The aim was to study the seroprevalence and efficacy of the different serological tests used for detection of antibody against Brucella species in small ruminants of Banaskantha district of North-Gujarat. MATERIALS AND METHODS: Total 1000 serum samples comprising of 485 from sheep and 515 from goat tested for detection of antibodies against the Brucella species by three different serological tests viz., Rose bengal plate test (RBPT), Standard tube agglutination test (STAT), and Indirect Enzyme-linked immunosorbent assay (I-ELISA). RESULTS: The seroprevalence of brucellosis in small ruminants was 11.30%, 11.10%, and 8.80% by RBPT, STAT, and I-ELISA, respectively. The seroprevalence of brucellosis was found to be higher in sheep than goats. The sensitivity of RBPT was found slight more than STAT, but the specificity of both tests was same. In this study, the overall agreement of RBPT and STAT with I-ELISA was found 92.50% and 92.30% in small ruminants, respectively. CONCLUSION: I-ELISA was a better serological test as compared to RBPT and STAT in the sense of sensitivity, specificity, and rapidity and it could be advocated for screening of brucellosis in sheep and goats.

Mutational analysis of two conserved sequence motifs in HIV-1 reverse transcriptase.

Two conserved sequence motifs, occurring in HIV-1 reverse transcriptase at residues 110-116 and 183-190, have been studied using site-directed mutagenesis of the cloned gene. In particular, aspartates at positions 185 and 186 have each been mutated to either asparagine or glutamate. The resulting mutant proteins were catalytically inactive but still able to bind the template-primer complex, poly rA-oligo dT. Other mutations in these regions resulted in reduced reverse trascriptase activity but the mutation of tyrosine-183 to serine caused a significant increase in the Km for dTTP and the Ki for inhibition by 3'-azidothymidine-triphosphate, 2',3'-dideoxythymidine-triphosphate and phosphonoformic acid.