Micro-morpho-anatomical transitions at various stages of in vitro development of Crinum malabaricum Lekhak and Yadav: A critically endangered medicinal plant

Crinum malabaricum Lekhak & Yadav is a recently discovered and critically endangered aquatic bulbous plant of the family Amaryllidaceae. It gained attention as a wild source of the acetylcholinesterase inhibiting alkaloid 'galanthamine' used to treat Alzheimer and Parkinson diseases. The bulbs of this plant contain the highest amount of galanthamine among Crinum species. In vitro regeneration systems were developed to produce quality uniform plantlets of C. malabaricum. Bright field light microscopy was used to analyse micro-morpho-anatomical developments taking place in the leaves and roots during in vitro, ex vitro and in vivo transitions of plantlets. Leaves and roots of plants raised in vitro possessed a higher degree of microscopic structural anomalies, such as underdeveloped epicuticular wax deposition, immature and non-functional stomata, more aquiferous parenchyma with a reduced lumen. Roots developed in vitro were characterized by extremely large, uneven cortical cells and reduced intercellular spaces. The vascular tissues were under-developed and only primary vascular tissues were observed. As a result of ex vitro acclimation, there was a significant acceleration in the improvement of tissue systems in leaves and roots. Such plantlets can tolerate elevated temperatures and light under in vivo conditions. Thus, the microscopic evaluation of the structural trajectory in different stages of plantlet development provides an understanding of the acclimation process and structural adaptations, which could help enhance survival of in vitro raised plantlets under ex vitro and in vivo conditions.

Gallbladder Cancer: A Single-Institution 10-Year Experience-Analysis of Adenocarcinoma Subtypes and Tumors Arising from Intracholecystic Papillary Neoplasms

BACKGROUND

Gallbladder cancer accounts for 1.2% of global cancer diagnoses. Literature on biliary-type adenocarcinoma (BTA), and specifically carcinoma arising from intracholecystic papillary-tubular neoplasms (ICPNs), is limited. This study describes a retrospective, single-institution experience with gallbladder cancer, focusing on histological subtypes and prognosis.

METHODS

A retrospective review was performed of patients who underwent cholecystectomy for a malignant neoplasm of the gallbladder between 2007 and 2017. Demographic, clinicopathologic, and operative variables, as well as survival outcomes, were analyzed.

RESULTS

From a total of 145 patients, BTAs were most common (93, 64%). Compared with non-BTAs, BTAs were diagnosed at a lower American Joint Committee on Cancer stage (p = 0.045) and demonstrated longer median recurrence-free survival (38 vs. 16 months, p = 0.014; median follow-up 36 months). Tumors arising from ICPNs (18, 12%) were more commonly associated with BTA (14 cases). Compared with BTAs not associated with ICPNs (29 patients), associated cases demonstrated lower pathologic stage (p = 0.006) and lower rates of liver and perineural invasion (0% vs. 49% and 14% vs. 48%, respectively; p < 0.05). Cumulative 5-year survival probability was higher for patients with gallbladder neoplasm of any subtype associated with ICPNs compared with those that were not associated with ICPNs (54% vs. 41%, p = 0.019; median follow-up 23 months). This difference was also significant when comparing BTAs associated with ICPNs and non-associated cases (63% vs. 52%, p = 0.005).

CONCLUSIONS

This study demonstrated unique pathological and prognostic features of BTAs and of carcinomas arising from ICPNs. Histopathological variance may implicate prognosis and may be used to better guide clinical decision making in the treatment of these patients.

Systematic green synthesis of silver oxide nanoparticles for antimicrobial activity

In this present research, we succeeded in synthesizing nanostructured silver particles (NS-AgPs) using bio active agent present in the leaf extracts of Cleome gynandra (CG) under green synthesis. While adding silver nitrate (AgNO₃) solution in green extracts of CG leaf containing bio compound, the mixture turns from yellow to reddish brown, as a consequence of existence of nanostructured silver particles (NS-AgPs) and later UV instrument is used to obtain the Ultraviolet visible spectroscopy (UV-vis) spectra to confirm existing nanostructured silver particles (NS-AgPs) in aqueous solutions (synthesized sample). To confirm existing functional groups in NS-AgPs, the fourier transform infrared spectroscopy (FTIR) study is carried throughout this research. The scanning and tunneling of wave like nature of electrons passing through powdered NS-AgPs sample gives Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) images respectively, which are carried out to find out the 2-dimensional size and shape distribution of NS-AgPs. Further dynamic light scattering (DLS) and zeta potential studies are used to confirm the size and good stability of NS-AgPs respectively. It is evident that NS-AgPs exhibits a strong toxic activity against microorganism and to confirm this mechanism the antibacterial (against Escherichia coli and Staphylococcus aureus) study is carried out.

Studies on the spectrometric analysis of metallic silver nanoparticles (Ag NPs) using Basella alba leaf for the antibacterial activities

In this present investigation, an aqueous Basella alba leaves extract was used to synthesize AgNPs. The green synthesis approach is carried out in our work due to non-toxic, less cost, and ecofriendly methods. FTIR spectra are used to confirm the biomolecules present in B.alba leaves extract along with AgNPs and these compounds are responsible for Ag particle from micro to nanostructure. The FCC structure and crystalline nature of the AgNPs are analyzed with the help of XRD and TEM techniques respectively. DLS and Zeta potential techniques are carried out to find the size and stability of AgNPs respectively and UV is used to verify the presence of AgNPs in synthesized samples employing SPR peaks around 435 nm. The antioxidant studies expose eminent scavenging activity which ranges from 13.71% to maximum 67.88%. Green synthesized AgNPs possess well organized biological activities concerning antioxidant and antibacterial, which can be used in some biologically applications.

A novel biogenic Allium cepa leaf mediated silver nanoparticles for antimicrobial, antioxidant, and anticancer effects on MCF-7 cell line

In the present study, Allium cepa leaf extract was utilized to reduce the silver nitrate into the nanoscale range of silver ions (Ag NPs). The biosynthesized Ag NPs were extensively characterized by X-ray diffraction analysis (XRD), Dynamic light scattering analysis (DLS), UV-Visible spectroscopy (UV-vis), Transmission electron microscopy (TEM), Energy dispersive X-ray analysis (EDX) and Fourier transform infrared spectroscopy (FTIR). The antioxidant activity of synthesized Ag NPs was verified by DPPH assay. From the results obtained from XRD and DLS studies, the size of Ag NPs was determined to be around 54.3 nm. The measured zeta potential value of -19.1 mV confirms the excellent stability of biosynthesized Ag NPs. TEM analyses reveal that the biosynthesized Ag NPs have a spherical structure of 13 nm in size. The presence of various functional groups was confirmed through FTIR studies and EDAX verifies the weight percentage of silver content in biosynthesized nanoparticles to be 30.33%. In the present study, anti-cancer activity was carried out by using breast cancer cell line MCF-7. Further, silver nanoparticles exhibited antimicrobial effectiveness against gram-positive Bacillus cereus and gram-negative Escherichia coli. The MTT assay also showed better cytotoxic activity against the MCF- 7 cell line.

POS1397 HYDROXYCHLOROQUINE INDUCED RETINAL TOXICITY IN PATIENTS WITH RHEUMATIC DISEASES

Background:

Retinal toxicity from hydroxychloroquine (HCQ) is rare, but the vision loss maybe irreversible and could have medicolegal consequences.

Objectives:

To determine the prevalence and assess the predictors of retinal toxicity due to HCQ in patients with rheumatic diseases. There is paucity of literature on retinal toxicity due to HCQ in rheumatic diseases.

Methods:

A retrospective observational study was conducted in the Department of Clinical Immnuology and Rheumatology, Sri Ramachandra Institute of Higher Education and Research,Chennai, India from November 2018-May 2020, on patients taking HCQ for more than 6 months. All patients underwent ophthalmological screening at baseline and every 6 months, and thereafter by modern day screening methods-Humphrey Visual Field (HVF)10-2, Spectral Domain Optical Coherence Tomography(SD-OCT), except for patients with evidence of suspected retinal toxicity at baseline.Fundus autofluorescence (FAF) was done in feasible patients.

Results:

9 out of 743(1.2%) patients were identified to have retinal toxicity, detected via fundus examination (n=9), SD-OCT (n=8/9), HVF 10-2 (n=6/9), FAF (n=1/9). 55.5% (n=5/9) had Rheumatoid Arthritis(RA) and 44.4% (n=4/9) had Systemic Lupus Erythematosus(SLE) as their primary diagnosis. 77.7% (n=7/9) were females. The mean age was 47.5 years (20-72 years).75%(n=3/4) of SLE patients were below 30 years of age. The average daily and cumulative dose of HCQ in these 9 patients were 244 mg (200-400mg) and 311.22g(73-730g)respectively, whereas the mean recommended dose as per real body weight was 287.2mg/day. Average duration of HCQ consumption was 3.6 years (1-10 years).Only 11.1% (n=1/9) had presented with visual complaints of black floaters.

Conclusion:

The asymptomatic nature of this irreversible toxicity, warrants frequent screening.Retinal toxicity was not age-related.Toxicity was manifested at low daily and cumulative doses.Screening should be done atleast every 6 months by fundus examination.Objective tests like HVF and SD-OCT should be done annually, especially in patients with underlying rheumatic diseases.The early manifestation of retinal toxicity in young SLE patients could have a genetic association and needs further evaluation.

References:

[1]Mortada A Abozaid et al. hydoxychloroquine retinopathy in a ohort of patients from upper Egypt.Journal of Egyptioan Ophthalmological Society 2017;110:110-113

[2]Roy AN,Samala V,Kumar YA,Fatima SS.Assessing the risk of retinopathy in Indian patients using hydroxychloroquine for rheumatic and musculoskeletal Diseases:A Retrospective Observational Study.Indian J Rheumatol 2020.

Disclosure of Interests:

None declared

AB0773 PATTERN OF MACROPHAGE ACTIVATION SYNDROME IN RHEUMATIC DISEASES

Background:

Macrophage activation syndrome (MAS) is a rare, potentially fatal condition complicating autoimmune diseases, as their initial manifestation or during its course.

Objectives:

To describe the pattern of MAS and its salient features in patients with rheumatic diseases.

Methods:

A retrospective observational study was conducted in 16 patients diagnosed with MAS, due to rheumatic diseases in Department of Rheumatology, SRIHER, Chennai from January 2018-December 2020.

Results:

The primary diseases were Systemic Lupus Erythematosus(SLE) in 75%(n=12),Adult Onset Still Disease(AOSD) in18.7%(n=3) and Kikuchi Disease in 6.25%(n=1). 50%(n=8) presented with MAS as the initial manifestation.Others had a known rheumatic disease with an average duration of 6.5 years.Occult MAS was seen in 25%(n=4). The most frequent clinical features were unremitting fever(n=15) and splenomegaly(n=15).All had hyperferritinemia-mean of 2971.10 ng/mL(531-12536).Sub group analysis showed significant hypofibrinogenemia(129.8 vs 200.62 mg/dl) in patients presenting with MAS as their initial manifestation.Transaminitis(666/252.5 vs 243/217.62 U/L), hypertriglyceridemia(316 vs 275.8 mg/dl), high LDH(2490 vs 938.75) were more severe in this group, but not significant.All with SLE had increased disease activity, with 50%(n=8) having SLEDAI 2K of ≥15.Bone marrow aspiration showed haemophagocytes in 81.25%(n=13).H score of >169 was seen in 93.75%(n=15). Infection was the commonest trigger for MAS(n=9)-bacterial(n=5), viral(n=4), fungal(n=1) and mycobacterial(n=2),followed by parturition(n=1).All patients were managed with pulse steroids followed by intravenous cyclophosphamide(n=8), rituximab(n=2), mycophenolate mofetil(n=2) in SLE, tocilizumab(n=2) and etoposide(n=1) in AOSD.Mortality rate was 18.75%(n=3).

Conclusion:

Spectrum of MAS in rheumatic diseases could be occult, associated with infection,high disease activity,or lead to mortality. High index of clinical suspicion is required, due to overlap of features like fever, cytopenias and organomegaly in MAS & SLE.Hyperferritinemia, high LDH, & transaminitis could aid in differentiating & early diagnosis. New criteria for rheumatic diseases,including these parameters are needed, especially in resource-limited settings where sIL-2Rα & NK cell activity tests are not feasible.

References:

[1]Stuart J.Carter et al. Macrophage activation syndrome in adults:Recent advances in pathophysiology, diagnosis and treatment. Rheumatology 2019;58;5-17

[2]Ai-Chun Liu et al.Macrophage activation syndrome in systemic lupus erythematosus:a multicentre,case-control study in China.Clin Rheumatol 2017.

Table 1.

MAS-SALIENT FEATURES

FEATURESINITIAL MANIFESTATIONS [n=8]KNOWN RHEUMATIC DISEASES[n=8]P VALUE(<0.05)Primary rheumatic diseasesSLE5(62.5%)7(87.5%)-AOSD2(25%)1(12.5%)Kikuchi disease1(12.5%)0Fever8(100%)7(87.5%)0.30Respiratory2(25%)5(62.5%)0.13Neurological1(12.5%)4(50%)0.10Bleeding2(25%)1(12.5%)0.52Splenomegaly8(100%)7(87.5%)0.30Hepatomegaly6(75%)3(37.5%)0.13Haemoglobin(g/dl)8.58(5.4-11.7)8.2(5.2-11.5)0.70WBC count(/μL)5550(1000-11800)3477.5(1200-6200)0.19Platelet count(x 109/l)1.41(0.30-2.4)1.35(0.32-1.8)0.90ESR(mm/hr)76.75(42-137)68(20-127)0.65AST(U/L)666(36-3481)257.75(45-642)0.36ALT(U/L)252.5(18-790)217.62(28-1044)0.82LDH(U/L)2490.12(164-16,000)938.75(357-1569)0.44Ferritin(ng/ml)2187.46(532-7500)3754.75(531-12536)0.37Triglycerides(mg/dl)316(53-551)275.8(160-317)0.52Fibrinogen(mg/dl)129.8(76-178)200.62(140-292)0.009Complement 3(mg/dl)39.14(13-60)[n=5]57.72(32-95)[n=7]0.16Complement 4(mg/dl)4.24(1.2-6)[n=5]14.22(2.8-34)[n=7]0.07Anti dsDNA antibodies[ELISA] IU/ml596.2(90-1151)[n=5]316.82(10-800)[n=7]0.26

MAS-Macrophage activation syndrome,WBC-white blood cell,ESR-erythrocyte sedimentation rate,AST-aspartate aminotransferase, ALT-alanine aminotransferase, LDH-lactate dehydrogenase, dsDNA-double standed deoxyribonucleic acid

Disclosure of Interests:

None declared

Application of flow cytometry in the analysis of lymphoid disease in the lung and pleural space

Various types of lymphoid neoplasms can occur in the lung. Lung parenchyma, the pleura or the pleural cavity can be the primary site of a lymphoid neoplasm or can be involved secondarily as a result of systemic dissemination from a separate primary site. Recognition of pulmonary lymphoid neoplasms (PLN) has increased secondary to technological advances in the medical field. Multiparameter flow cytometry (FC) is a one of the diagnostic tools that serves an essential role in the detecting and categorizing PLNs. FC allows for rapid identification and immunophenotypic characterization of PLN. In this article, we discuss the role of FC in the diagnosis of the most commonly encountered PLNs as well as their basic clinicopathologic features. We briefly discuss the role of FC in identifying non-hematolymphoid neoplasms in lung specimens as well.

Recurrent metastatic primary inflammatory myofibroblast tumour of the gallbladder following pancreaticoduodenectomy

Inflammatory myofibroblast tumour (IMT) is an uncommon soft tissue tumour with an unpredictable clinical course: mostly benign, occasionally locally aggressive and rarely capable of metastasis. Diagnosed mainly in the mesentery, omentum, retroperitoneum, pelvis and lungs, IMT is extremely rare as a primary gallbladder tumour. Despite improved radiographical capabilities, differentiating the tumour from other more common causes of gallbladder neoplasms necessitates histopathological and immunohistochemistry tests. Once diagnosed, malignant potential should be taken into consideration, striving for an en bloc R0 resection and postoperative long-term follow-up with routine ancillary imaging. The authors present the case of a recurrent primary IMT of the gallbladder, after two surgical treatments, including a pancreaticoduodenectomy. Now 3 years after initial diagnoses the patient is asymptomatic, but has developed local and distant metastases and is being treated with systemic corticosteroid.

Squamous Cell Carcinoma From Marjolin's Ulcer of the Foot in a Diabetic Patient: Case Study

Squamous cell carcinoma (SCC) has been commonly reported by foot and ankle specialists. Marjolin's ulcer is a malignancy that involves a posttraumatic scar or ulceration that can develop into SCC from chronic neuropathic pedal wounds, venous stasis, or decubitus ulcerations. Most Marjolin's ulcers are found in the lower extremity, specifically the feet, and it is twice as common in females as males. Biopsy of the tumor is the reference standard to diagnose SCC, and wide excision of SCC is the most common treatment option. The present case study describes an 83-year-old diabetic wheelchair-bound female who presented to the wound care clinic with a right heel nonhealing pressure ulceration. After biopsy and surgical excision, the patient was found to have SCC. This case was followed up for 5 years in which the patient had successful excision of the tumor with no recurrence. The clinical significance of our case study is to assist in the diagnosis, management, and prognosis of patients with SCC. In addition, this study has shown that adequate excision of the tumor margins and depth is necessary to prevent potential recurrence and metastasis.

Survival and risk of breast cancer recurrence after breast reconstruction with deep inferior epigastric perforator flap

BACKGROUND

Women who undergo autologous breast reconstruction have been reported to have an increased risk of breast cancer recurrence compared with those who have mastectomy alone. It has been suggested that more extensive surgery possibly activates dormant micrometastases. The aim of this study was to evaluate whether delayed unilateral deep inferior epigastric perforator (DIEP) flap reconstruction after mastectomy increases the risk of breast cancer recurrence or affects mortality among women previously treated for breast cancer.

METHODS

This was a matched retrospective cohort study including women with a previous unilateral invasive breast cancer who received a delayed DIEP flap breast reconstruction and a control cohort of individually matched women with unilateral breast cancer who underwent mastectomy but no autologous breast reconstruction. Matching criteria comprised: year of diagnosis (+/-3 years), age at diagnosis (+/-5 years), type of cancer and demographic region. The primary endpoints were local recurrence or distant metastasis, and overall mortality was a secondary endpoint. Absolute risk of recurrent disease and mortality was analysed, and relative risks were estimated using Cox proportional hazards analysis.

RESULTS

There were 225 women in the DIEP cohort and 450 in the no-DIEP cohort. The median follow-up time was 125 months. There was no difference in absolute risk of recurrence between the cohorts. The hazard ratio for breast cancer recurrence in DIEP versus no-DIEP cohorts was 0·76 (95 per cent c.i. 0·47 to 1·21).

CONCLUSION

There is no increased risk in breast cancer recurrence after delayed DIEP flap reconstruction compared with mastectomy alone.

International validation of the European Organisation for Research and Treatment of Cancer QLQ-BRECON23 quality-of-life questionnaire for women undergoing breast reconstruction

Background

The aim was to carry out phase 4 international field-testing of the European Organisation for Research and Treatment of Cancer (EORTC) breast reconstruction (BRECON) module. The primary objective was finalization of its scale structure. Secondary objectives were evaluation of its reliability, validity, responsiveness, acceptability and interpretability in patients with breast cancer undergoing mastectomy and reconstruction.

Methods

The EORTC module development guidelines were followed. Patients were recruited from 28 centres in seven countries. A prospective cohort completed the QLQ-BRECON15 before mastectomy and the QLQ-BRECON24 at 4–8 months after reconstruction. The cross-sectional cohort completed the QLQ-BRECON24 at 1–5 years after reconstruction, and repeated this 2–8 weeks later (test–retest reliability). All participants completed debriefing questionnaires.

Results

A total of 438 patients were recruited, 234 in the prospective cohort and 204 in the cross-sectional cohort. A total of 414 reconstructions were immediate, with a comparable number of implants (176) and donor-site flaps (166). Control groups comprised patients who underwent two-stage implant procedures (72, 75 per cent) or delayed reconstruction (24, 25 per cent). Psychometric scale validity was supported by moderate to high item-own scale and item-total correlations (over 0·5). Questionnaire validity was confirmed by good scale-to-sample targeting, and computable scale scores exceeding 50 per cent, except nipple cosmesis (over 40 per cent). In known-group comparisons, QLQ-BRECON24 scales and items differentiated between patient groups defined by clinical criteria, such as type and timing of reconstruction, postmastectomy radiotherapy and surgical complications, with moderate effect sizes. Prospectively, sexuality and surgical side-effects scales showed significant responsiveness over time (P &lt; 0·001). Scale reliability was supported by high Cronbach's α coefficients (over 0·7) and test–retest (intraclass correlation more than 0·8). One item (finding a well fitting bra) was excluded based on high floor/ceiling effects, poor test–retest and weak correlations in factor analysis (below 0·3), thus generating the QLQ-BRECON23 questionnaire.

Conclusion

The QLQ-BRECON23 is an internationally validated tool to be used alongside the EORTC QLQ-C30 (cancer) and QLQ-BR23 (breast cancer) questionnaires for evaluating quality of life and satisfaction after breast reconstruction.

Emergence of HIV-1 drug-resistant variants in women following antiretroviral prophylaxis for the prevention of mother to child transmission

PURPOSE

Emergence of drug resistance following HIV prophylaxis has an important impact on ART program.

OBJECTIVE

To investigate the emergence of drug resistance in HIV-1 infected pregnant women.

MATERIALS AND METHODS

Fifty-three HIV-1 infected pregnant women who had received 4-12 weeks of antenatal AZT followed by Nevirapine during delivery and Combivir [AZT + 3TC] for 1 week postpartum (group-1, n = 48) or who come at the time of delivery and received Nevirapine followed by Combivir for 1 week (group-2, n = 5) were recruited. Samples were collected prior to the start of the prophylaxis and 5-8 weeks postpartum. In addition, a third sample was collected between 26-65 weeks postpartum from 7 women. Amplification of HIV-1 pol gene and drug resistance analysis was done.

RESULT

Two (3.8%) women in group-1 showed transmitted drug resistance and they continued to show this even at 6 weeks postpartum. One (2%) woman from group-1 showed a mutation after 6-8 weeks of prophylaxis. Among the samples collected between 26-65 weeks postpartum, 3/7 (43%) showed mutations and all these women belong to group-1. Women belonging to group-2 didn't show mutation prior to or following prophylaxis.

CONCLUSION

In contrast to the available data among pregnant women with ART prophylaxis, our data showed reduced frequency of mutations following 5-8 weeks of postpartum but an emergence of mutation later (26-65 weeks). The addition of Combivir with the single dose Nevirapine during delivery and the early stage of the disease with higher CD4 counts could be the reasons for this.

Neural bases of selective attention in action video game players

Over the past few years, the very act of playing action video games has been shown to enhance several different aspects of visual selective attention, yet little is known about the neural mechanisms that mediate such attentional benefits. A review of the aspects of attention enhanced in action game players suggests there are changes in the mechanisms that control attention allocation and its efficiency (Hubert-Wallander, Green, & Bavelier, 2010). The present study used brain imaging to test this hypothesis by comparing attentional network recruitment and distractor processing in action gamers versus non-gamers as attentional demands increased. Moving distractors were found to elicit lesser activation of the visual motion-sensitive area (MT/MST) in gamers as compared to non-gamers, suggestive of a better early filtering of irrelevant information in gamers. As expected, a fronto-parietal network of areas showed greater recruitment as attentional demands increased in non-gamers. In contrast, gamers barely engaged this network as attentional demands increased. This reduced activity in the fronto-parietal network that is hypothesized to control the flexible allocation of top-down attention is compatible with the proposal that action game players may allocate attentional resources more automatically, possibly allowing more efficient early filtering of irrelevant information.

Bacterial identification in the diagnostic laboratory: how much is enough?

The major impetus for bacterial identification came after the advent of solid culture media. Morphological appearance of bacterial colonies was often sufficient for their identification in the laboratory. Even in modern times, preliminary identification of most cultivable bacteria is based on such morphological characters. Advances have been made media for the presumptive identification of common organisms encountered in clinical samples. Phenotypic characterisation of bacteria with, physiological tests with a battery of biochemical tests differentiate related bacterial genera as well as confirm their identity. . Each laboratory can select its own method(s) of identification, provided they are based on scientific / epidemiological evidence; clinical laboratory and standards institute (CLSI) is a widely accepted organization and laboratories in many parts of the world follow its recommendations for bacterial identification. Some of the latest advances in identification include Matrix Assisted Laser Desorption Ionization - Time of Flight Mass Spectroscopy (MALDI-TOF) is a state of art facility used for fast and reliable species-specific identification of bacteria including Mycobacteria and fungi including yeasts. However the single most important factor that decides the method of bacterial identification in any laboratory is the cost involved. In the final analysis, selection of tests for bacterial identification should be based on their standardization with proper scientific basis. Considering the cost and lack of easy availability of commercial kits, we have put forward a simplified and rapid method of identification for most commonly encountered bacterial pathogens causing human infection in India.

Botanical ratchets

Ratcheting surfaces are a common motif in nature and appear in plant awns and grasses. They are known to proffer selective advantages for seed dispersion and burial. In two simple model experiments, we show that these anisotropically toothed surfaces naturally serve as motion rectifiers and generically move in a unidirectional manner, when subjected to temporally and spatially symmetric excitations of various origins. Using a combination of theory and experiment, we show that a linear relationship between awn length and ratchet efficiency holds under biologically relevant conditions. Grass awns can thus efficiently transform non-equilibrium environmental stresses from such sources as humidity variations into useful work and directed motion using their length as a fluctuation amplifier, yielding a selective advantage to these organelles in many plant species.

Extracorporeal irradiation for pelvic reconstruction in Ewing’s sarcoma

We review the treatment of pelvic Ewing’s sarcoma by the implantation of extracorporeally-irradiated (ECI) autografts and compare the outcome with that of other reported methods.

We treated 13 patients with ECI autografts between 1994 and 2004. There were seven males and six females with a median age of 15.7 years (interquartile range (IQR) 12.2 to 21.7). At a median follow-up of five years (IQR 1.8 to 7.4), the disease-free survival was 69% overall, and 75% if one patient with local recurrence after initial treatment elsewhere was excluded. Four patients died from distant metastases at a mean of 17 months (13 to 23). There were three complications which required operative intervention; one was a deep infection which required removal of the graft. The functional results gave a mean Musculoskeletal Tumor Society score of 85% (60% to 97%), a mean Toronto extremity salvage score of 86% (69% to 100%) and a mean Harris hip score of 92 (67 to 100).

We conclude that ECI grafting is a suitable form of treatment for localised and resectable pelvic Ewing’s sarcoma.

Expression patterns of inhibitor of apoptosis proteins in malignant pleural mesothelioma

Inhibitor of apoptosis proteins (IAPs) comprise a family of structurally similar proteins, five of which are widely studied in the context of cancer: IAP-1/MIHC/cIAP2, IAP-2/MIHB/cIAP1, livin/ML-IAP/KIAP, survivin, and XIAP/MIHA/hILP. IAPs are overexpressed by most neoplasms, promote tumour cell survival after a wide variety of apoptotic stimuli, and frequently have gene and/or protein expression patterns associated with a relatively poor prognosis. However, many IAPs are also expressed by normal tissues, can facilitate apoptotic cell death, and have expression patterns associated with a relatively favourable prognosis in some cases. The result is that the precise role(s) of IAPs in human tumours is not exactly known. It has been previously reported that IAP-1 is overexpressed in malignant pleural mesothelioma (MPM) and is responsible for a large degree of the resistance of cultured MPM cells to cisplatin. Given the high homology of IAP family members, it is likely that other IAPs will be important in MPM. In the present study, the gene and protein expression patterns of IAP-1, IAP-2, survivin, livin, and XIAP have been determined in MPM cell lines (n=9) and a large number of MPM tumours using high-density oligonucleotide microarrays (n=40) and an MPM tissue array (n=66). Human tumours were linked to clinical data and it was found that IAP-1 and survivin mRNA expression patterns were associated with a relatively shorter patient survival, while those of XIAP and livin were associated with a relatively longer patient survival. Abundant protein for all IAPs was also detected in MPM tumours, where they were expressed primarily in the cytoplasm. Only IAP-1 and livin protein was expressed in the nucleus of MPM tumours. These results provide the rationale for additional study of this gene family in MPM and cancer in general.

Inhibitor of apoptosis proteins are regulated by tumour necrosis factor-alpha in malignant pleural mesothelioma

Inhibitor of apoptosis proteins (IAPs) are overexpressed by most neoplasms and promote tumour cell survival after a wide variety of apoptotic stimuli elicited via intrinsic (ie mitochondrial) and extrinsic (ie death receptor) pathways. It has previously been reported that one of these proteins, IAP-1(MIHC/cIAP2), is overexpressed in malignant pleural mesothelioma (MPM) and is responsible for a large degree of the resistance of cultured MPM cells to cisplatin. Subsequent analysis in a larger number of human tumours revealed that additional IAPs (eg IAP-2/MIHB/cIAP1, livin/ML-IAP/KIAP, survivin, and XIAP/MIHA/hILP) are also overexpressed in MPM and, with the exception of IAP-2, have expression patterns that correlate with prognosis. In the present study, potential regulatory mechanisms of IAP genes in MPM were investigated and it was found that tumour necrosis factor-alpha (TNF-alpha) can increase mRNA and protein levels of IAP-1, IAP-2, and XIAP, but not livin or survivin in MPM cell lines (n=4). It was also found that IAP gene expression levels are increased concomitantly with translocation to the nucleus of the TNF-responsive transcription factor NF-kappaB. Co-incubation of MPM cells with TNF-alpha and pyrrolidine dithiocarbamate (PDTC), an NF-kappaB inhibitor, prevented TNF-mediated up-regulation of IAP gene expression levels. In survival studies, TNF-alpha was not toxic to MPM cells at any concentration examined. However, MPM cells exposed to TNF-alpha were twice as resistant to cisplatin in dose response survival assays compared with unstimulated controls and were found to have a significantly greater fraction of surviving cells at multiple cisplatin concentrations (p<0.0087). Finally, it was found that levels of circulating TNF-alpha were statistically significantly (p=0.031) (median 312.5 pg/ml) higher in MPM patients (n=6) prior to surgical tumour debulking compared with those after surgery (median 0 pg/ml). These results when combined with previous observations by our laboratory and others strongly suggest that IAPs act synergistically with TNF family members to promote survival of MPM tumour cells after exposure to cisplatin and possibly other chemotherapeutic drugs.

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus: a multicentre study

PURPOSE

Methicillin resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen. We report the prevalence and antibiotic susceptibility pattern of MRSA in major southern districts of Tamilnadu.

METHODS

A total of 7172 clinical specimens and 1725 carrier screening samples were collected from different centers and subjected to MRSA screening using conventional microbiological methods. Subsequently the antibiotic sensitivity test was performed for the confirmed MRSA isolates.

RESULTS

Out of 906 strains of S. aureus isolated from clinical and carrier samples, 250 (31.1%) and 39 (37.9%) were found to be methicillin resistant respectively. Almost all clinical MRSA strains (99.6%) were resistant to penicillin, 93.6% to ampicillin, and 63.2% towards gentamicin, co-trimoxazole, cephalexin, erythromycin, and cephotaxime. All MRSA strains (100%) of carrier screening samples had resistance to penicillin and about 71.8% and 35.9% were resistant to ampicillin and co-trimoxazole respectively. Multidrug resistance was observed among 63.6% of clinical and 23% of carrier MRSA isolates. However, all strains of clinical and carrier subjects were sensitive to vancomycin.

CONCLUSION

The determination of prevalence and antibiotic sensitivity pattern of MRSA will help the treating clinicians for first line treatment in referral hospitals.

1,3,5-Triiodo-2,4,6-trimethylbenzene at 293 K

In the structure of triiodomesitylene (1,3,5-triiodo-2,4,6-trimethylbenzene), C(9)H(9)I(3), at 293 K, the benzene ring is found to be significantly distorted from ideal D(6h) symmetry; the average endocyclic angles facing the I atoms and the methyl groups are 123.8 (3) and 116.2 (3) degrees, respectively. The angle between the normal to the molecular plane and the normal to the (100) plane is 5.1 degrees. No disorder was detected at 293 K. The thermal motion was investigated by a rigid-body motion tensor analysis. Intra- and intermolecular contacts are described and topological differences compared with the isomorphous compounds trichloromesitylene and tribromomesitylene are discussed.

Merits of performing coronary artery by-pass grafts on the beating heart

A retrospective study of 1006 patients was undertaken to evaluate the benefit of a change of strategy in performing coronary artery by-pass grafting surgery. Group A consisted of 500 patients who were consecutively operated on cardiopulmonary by-pass and group B consisted of 506 patients who were consecutively operated on using "off pump" techniques. Pre-operative risk profile in both groups were similar as was as in the operating time. There was distinct benefit in amount of homologous transfusion, period of ICU stay, increased usage of radial artery conduit and improvement in transoesophageal echocardiography assessment of ischaemic mitral incompetence immediately after revascularisation in off pump (group B). Though there was a lower mortality in group B ie, 3/506 vis-a-vis 10/500 in group A this is not of statistical significance. Improvement in left ventricular ejection fraction >5.0% occurred more frequently in one month follow-up visits of group B patients. Period of return to active life was also shorter (28 versus 56 days). Based on observations, we conclude that there is a distinct benefit in avoiding cardiopulmonary by-pass while performing coronary artery by-pass grafting.

Chemosensitivity of lymphocytes from patients with B-cell chronic lymphocytic leukemia to chlorambucil, fludarabine, and camptothecin analogs

Chemosensitivity of B lymphocytes, obtained from 65 patients with B-cell chronic lymphocytic leukemia (B-CLL), Rai stages 0 through IV, was determined using the MTT assay. The results were expressed by the drug concentration required for 50% inhibition of cell viability (IC50). The cytotoxicity of chlorambucil (CLB) was compared with that of fludarabine and the DNA topoisomerase I inhibitors, camptothecin, 9-aminocamptothecin, 10,11-methylenedioxy-20(S)-camptothecin (10,11-MDC) and 9-amino-10,11-methylenedioxy-20(S)-campthothecin (9-A-10,11-MDC), and topotecan. Considerable heterogeneity in sensitivity to CLB was observed, with a median IC50 of 40.5 mumol/L in untreated patients. B-CLL cells from patients treated with CLB had a significantly higher median IC50 of 86.0 mumol/L (P < .01). Untreated as well as CLB-treated patients were divided into two subsets. For the purpose of this study, B-CLL lymphocytes with an IC50 CLB of less than 61.0 mumol/L were designated as "sensitive" and those with an IC50 CLB of > or = 61.0 mumol/L were designated as "resistant." After baseline assays, 15 untreated patients received CLB; after treatment, the IC50 increased in B-CLL lymphocytes from 13 of 15 patients. The response to CLB treatment, determined by its effect on the absolute lymphocyte count and by the Eastern Cooperative Oncology Group clinical criteria, was significantly better in patients whose lymphocytes had an IC50 CLB of less than 61.0 mumol/L before therapy (P < .01). B-CLL lymphocytes also had a variable degree of sensitivity in vitro to each of the other drugs. There was significant cross-resistance between CLB and fludarabine (P < 0.01). Whereas only 29% of CLB-resistant B-lymphocyte specimens obtained from individual patients were sensitive to fludarabine in vitro, 52% and 67% of CLB-resistant lymphocyte samples were sensitive to 10,11-MDC and 9-A-10,11-MDC, respectively. We have previously reported that p53 gene mutations were associated with aggressive B-CLL and a poor prognosis. B lymphocytes from seven patients with these mutations were resistant to CLB, and five of six were resistant to fludarabine. Lymphocytes from four of seven were resistant to 10,11-MDC, and three of four were resistant to 9-A-10,11-MDC. This study implies that the MTT assay may be useful in identifying subsets of CLL patients resistant to conventional chemotherapy. However, definitive conclusions can not be drawn in view of the small number of patients studied prospectively. In addition, these results suggest the potential of camptothecin-based therapy for patients unresponsive to standard treatment.