Silver nanoparticles induces apoptosis of cancer stem cells in head and neck cancer

Background

Several nano formulations of silver nanoparticles with bioconjugates, herbal extracts and anti-cancerous drug coating have been vividly studied to target cancer. Despite of such extensive studies, AgNPs (silver nanoparticles) have not reached the stage of clinical use. Out of all possible reasons for this failure, the unexplored effect on Cancer Stem Cell (CSC) population and mechanism of action of AgNPs, are the most plausible ones and are worked upon in this study.

Methods

AgNPs were synthesized by chemical reduction method using sodium citrate and characterized by UV, FTIR, XRD and electron microscopy. CSC population was isolated from Cal33 cell line by MACS technique. MTT assay, trypan blue exclusion assay, Annexin V and PI based apoptosis assay and cell cycle assay were performed.

Results

The results showed that synthesized AgNPs have cytotoxic activity on all cancer cell lines tested with the IC50 value of a wide range (1.5-49.21 µg/ml for cell lines and 0.0643-0.1211 µg/ml for splenocytes and thymocytes). CSCs Cal33 showed higher resistance to AgNP treatment and arrest in G1/G0 phase upon cell cycle analysis.

Conclusion

AgNPs as an anti-cancer agent although have great potential but is limited by its off-target effects on normal cells and less effective on cancer stem cells at lower concentrations.

Landscaping tuberculosis multimorbidity: findings from a cross-sectional study in India

BACKGROUND

Multimorbidity, the concurrent presence of two or more chronic conditions is an emerging public health challenge. Till date, most of the research have focused on the presence and interaction of selected co-morbidities in tuberculosis (TB). There exist a critical knowledge gap on the magnitude of multimorbidity among TB patients and its impact on health outcomes.

METHODS

We undertook a cross-sectional study to assess the prevalence and patterns of multimorbidity among newly diagnosed TB patients in two states of India. A total of 323 patients were interviewed using a structured multimorbidity assessment questionnaire for primary care (MAQ-PC). MAQ-PC is already validated for Indian population and elicits 22 chronic conditions. We defined TB multimorbidity as the co-existence of TB with one or more chronic conditions and identified commonly occurring dyads (TB + single condition) and triads (TB + two conditions).

RESULTS

More than half (52%) of TB patients reported multimorbidity. Among dyads, depression, diabetes mellitus (DM), acid peptic disease (APD), hypertension, chronic alcoholism, arthritis and chronic back ache (CBA) were the most common co-occurring conditions while 'DM + arthritis', 'depression + APD', 'depression + DM' were the most commonly occurring triads among TB patients. Factors such as increasing age, low levels of education, alcohol abusers, drug-resistant TB and having health insurance were significantly associated with multimorbidity among TB patients.

CONCLUSIONS

Our findings suggest high prevalence of multimorbidity among newly diagnosed TB patients in India. The presence of concordant and discordant conditions with TB may increase the health complexity, thus necessitating appropriate care protocols. Given, the current situation, wherein TB and non-communicable diseases (NCD) services are delivered through collaborative framework between programmes, there is a need for addressing multimorbidity at the healthcare delivery level.

The Multifunction Role of Tumor-Associated Mesenchymal Stem Cells and Their Interaction with Immune Cells in Breast Cancer

Mesenchymal stem cells (MSCs) are a heterogeneous group of progenitor cells that play a multifunctional role including tissue regeneration, self-renewal properties, and differentiate into cells of mesodermal lineage such as adipocytes, osteoblasts, and chondrocytes. MSCs come into contact with tumor microenvironment (TME) and differentiate into tumor-associated MSCs (TA-MSCs). Various substances such as chemokines, cytokines, growth factors, and others are released by tumor cells to recruit MSCs. TA-MSCs induced epithelial-mesenchymal transition (EMT) program which mediates tumor growth progression, migration, and invasion. Role of MSCs in the tumor progression, stemness, malignancy, and treatment resistance in the breast cancer TME. Immunomodulation by MSCs is mediated by a combination of cell contact-dependent mechanisms and soluble substances. Monocytes/macrophages, dendritic cells, T cells, B cells, and NK cells all show signs of MSCs' immunomodulatory capability. In a complicated interplay initiated by MSCs, anti-inflammatory monocytes/macrophages and regulatory T cells (Tregs) play a key role, as they unveil their full immunomodulatory potential. MSC- secreted cytokines are commonly blamed for the interaction between MSCs, monocytes, and Tregs. Here, we review the current knowledge of cellular and molecular mechanisms involved in MSC-mediated immunomodulation and focus on the role MSCs play in breast cancer progression and its TME.Abbreviation MSC: Mesenchymal Stem Cells; TME: Tumor Microenvironment; TAMS; Tumour-associated Macrophages; ECM: Extracellular matrix; CAFs: Cancer-associated Fibroblasts; CFUs: Colony-forming unit Fibroblasts; Tregs: T regulatory cells; Bregs; Regulatory B cells; IFN-γ: Interferon-gamma; TNF-α: Tumour Necrosis Factor-alpha; IL: Interleukin; TGF-β: transforming growth factorβ; PGE2: Prostaglandin E2; CXCR: Chemokine Receptor; Blimp-1; B lymphocyte-induced maturation protein-1; CCL: Chemokine motif ligand; EMT: Epithelial-mesenchymal transition.

Effects of oral probiotic and lactoferrin interventions on iron-zinc homeostasis, oxidant/antioxidant equilibrium and diarrhoea incidence of neonatal piglets

The objective of this study was to examine the effects of early-life host specific probiotic and lactoferrin (LF) supplementations on diarrhoea incidence, iron (Fe)-zinc (Zn) balance and antioxidant capabilities in serum of neonatal piglets. A total of eight sow litters obtained from parity matched sows were randomly divided into four groups and assigned to one of the four interventions: control (2.0 ml normal saline), bovine lactoferrin (bLF) (100 mg bLF in normal saline), probiotic (Pb) (1×10⁹ cfu of swine origin Pediococcus acidilactici FT28 strain) and bLF+Pb (both 100 mg bLF and 1×10⁹ cfu of P. acidilactici FT28). All the piglets received supplementations once daily orally for first 7 days of life. The incidence of diarrhoea markedly decreased in bLF group compared to control group. Notably, no incidences of diarrhoea were recorded in Pb and bLF+Pb groups. The Zn and Fe concentrations were significantly increased from day 7 to 21 in bLF and on day 21 in bLF+Pb group. No such changes were noted in Pb group. Total antioxidant capacity (TAC) in serum was significantly increased on days 7 and 15 in bLF group and on days 7 and 21 in bLF+Pb group. Malonaldehyde concentration was markedly reduced from day 7 to 21 in bLF and bLF+Pb groups. The concentrations of nitrate on days 15 and 21 and malonaldehyde on day 7 were significantly higher in Pb group, but mean TAC was unaltered from day 0 to 21. Although no correlation between the incidence of diarrhoea and Zn/Fe and oxidant/antioxidant homeostasis was noted in the Pb group, the supplementation of P. acidilactici FT28 alone was sufficient to prevent the incidence of diarrhoea in neonatal piglets. Taken together, it is concluded that strategic supplementation of P. acidilactici FT28 in early life could help in preventing diarrhoea until weaning of piglets.

Characterisation and comparison of immune response mechanisms in an indigenous and a commercial pig breed after classical swine fever vaccination

The live attenuated classical swine fever (CSF) vaccine has been successfully used to prevent and control CSF outbreaks for 6 decades. However, the immune response mechanisms against the vaccine remain poorly understood. Moreover, very few reports exist regarding the breed differences in the response to CSF vaccine. In this study, we generated the peripheral blood mononuclear cell transcriptomes of indigenous Ghurrah and commercial Landrace pig breeds, before and 7 days after CSF vaccination. Subsequently, between and within-breed differential gene expression analyses were carried out. Results revealed large differences in pre-vaccination peripheral blood mononuclear cell transcriptome profiles of the two breeds, which were homogenised 7 days after vaccination. Before vaccination, gene set enrichment analysis showed that pathways related to antigen sensing and innate immune response were enriched in Ghurrah, while pathways related to adaptive immunity were enriched in Landrace. Ghurrah exhibited greater immunomodulation compared to Landrace following the vaccination. In Ghurrah, cell-cycle processes and T-cell response pathways were upregulated after vaccination. However, no pathways were upregulated in Landrace after vaccination. Pathways related to inflammation were downregulated in both the breeds after vaccination. Key regulators of inflammation such as IL1A, IL1B, NFKBIA and TNF genes were strongly downregulated in both the breeds after vaccination. Overall, our results have elucidated the mechanisms of host immune response against CSF vaccination in two distinct breeds and revealed common key genes instrumental in the global immune response to the vaccine.

Fractional flow reserve derived from computed tomography coronary angiography in the assessment and management of stable chest pain: the FORECAST randomized trial

Aims 

Fractional flow reserve (FFR_CT) using computed tomography coronary angiography (CTCA) determines both the presence of coronary artery disease and vessel-specific ischaemia. We tested whether an evaluation strategy based on FFR_CT would improve economic and clinical outcomes compared with standard care.

Methods and results 

Overall, 1400 patients with stable chest pain in 11 centres were randomized to initial testing with CTCA with selective FFR_CT (experimental group) or standard clinical care pathways (standard group). The primary endpoint was total cardiac costs at 9 months. Secondary endpoints were angina status, quality of life, major adverse cardiac and cerebrovascular events, and use of invasive coronary angiography. Randomized groups were similar at baseline. Most patients had an initial CTCA: 439 (63%) in the standard group vs. 674 (96%) in the experimental group, 254 of whom (38%) underwent FFR_CT. Mean total cardiac costs were higher by £114 (+8%) in the experimental group, with a 95% confidence interval from −£112 (−8%) to +£337 (+23%), though the difference was not significant (P = 0.10). Major adverse cardiac and cerebrovascular events did not differ significantly (10.2% in the experimental group vs. 10.6% in the standard group) and angina and quality of life improved to a similar degree over follow-up in both randomized groups. Invasive angiography was reduced significantly in the experimental group (19% vs. 25%, P = 0.01).

Conclusion 

A strategy of CTCA with selective FFR_CT in patients with stable angina did not differ significantly from standard clinical care pathways in cost or clinical outcomes, but did reduce the use of invasive coronary angiography.

126 White-Eyed Blowout Fracture in The Paediatric Patient Thought to Be A Head Injury – A Missed Diagnosis

White eyed blowout fracture or ‘trapdoor fracture’ is an orbital floor injury caused by blunt force trauma directly to the orbit causing ocular muscle entrapment between fractured bones of the floor of the orbit. It is most commonly encountered in the paediatric patient population and presents acutely with little to no periorbital signs of injury. This serious diagnosis is frequently missed at initial presentation due to a lack of obvious soft tissue pathology, termed “White Eyed” blow out fracture. It is frequently misdiagnosed as a head injury due to presenting nausea and vomiting and failure to examine eye movements.

The authors present a case of a 15-year-old male who suffered blunt force trauma to the orbit and a white eyed blowout fracture ensued. This was not identified in the emergency department and the patient consequently suffered permanent motility deficit of the globe. We outline recommendations for emergency department practitioners to help identify such presentations and see their timely surgical management.

PRODUCTION AND OPTIMIZATION OF CYCLODEXTRIN GLUCANOTRANFERASE FROM BACILLUS SP. SS2

An extracellular cyclodextrin glucanotranferase enzyme producing bacterium was isolated from the soil sample collected from Dumas Beach, Surat, India. The isolate was biochemically, physiologically, and phylogenetically characterized and was identified as a strain of Bacillus cereus group. The production of CGTase enzyme was optimized using various starch sources as substrates such as soluble starch, corn starch, potato starch, and rice starch. The enzyme production was found to be maximum when potato starch was added in the medium as substrate. The enzyme activity was measured as 5.132±0.25 U/mL in soluble starch, 8.423±0.33U/mL in corn starch, 14.329 ± 0.14 U/mL in potato starch, and 12.762 ± 0.09 U/mL in rice starch. The optimization of operating parameters such as pH, incubation temperature, potato starch concentration, incubation time, and agitation speed affecting enzyme production was further carried out using Response Surface Methodology, a combined method of statistical and mathematical approach. Central Composite Design was selected for optimization and the optimum levels of these parameters were identified as 8.8, 38°C, 2.2%, 50 h, and 200 rpm for pH, incubation temperature, potato starch concentration, incubation time, and agitation speed respectively. The final CGTase enzyme activity at the optimum levels of all the factors was measured to be as 38.313 U/mL which was in agreement with the software predicted enzyme activity of 39.901 U/mL and was more than twice the original activity. This study demonstrates the utility of strain SS2 for CGTase production which can be used as an alternative for commercial cyclodextrin production.

AB1151 COMPLIANCE/CONCORDANCE WITH MYCOPHENOLATE MOFETIL IN PATIENTS WITH CONNECTIVE TISSUE DISORDERS IN COVENTRY

Background:

Connective tissue disorders like Systemic lupus erythematosus (SLE) are multi-organ systemic conditions characterised by disordered immune function. Mycophenolate Mofetil (MMF) is commonly used for treatment of SLE1and other connective tissue disorders like Sjogren’s syndrome, myositis and Scleroderma. Compliance with drugs remains a significant issue in management of these conditions and varying reports from across the world2,3continue to show significant lack of concordance resulting in increased disease activity and damage.

Objectives:

The aim of this study was to investigate the compliance/concordance specifically with MMF treatment among patients attending clinics at University Hospitals Coventry and Warwickshire NHS Trust (UHCW)with SLE and other connective tissue disorders.

Methods:

Ethical approval was obtained through research and development department within the Trust. This is a retrospective study collating non-identifiable hospital pharmacy data in patients who requested the prescription for MMF drug between January 2015 and December2018. Since MMF was required to be prescribed from the hospital (i.e. General practitioners within the region were unable to prescribe it), we have records for all prescriptions for these patients. We extracted information on sample size, frequency of prescription requested and length of follow up. Clinical data were obtained from paper and electronic notes of the patients. Data were analysed using the data analysis tool pack for linear regression, on Microsoft Excel package version 16.29.1.

Results:

We recruited 144 patients into this study, (74%) of these are females. Age range for this group was 2-89 years, median age was 45 (±11.2) years with a mean (±SD) age of 35.6 (±11.2) years and a disease duration of 8.8 (±6.2) years. 73.1% were White British, the remaining included 8.3% Indian, 5.5% Pakistani, 2.7% Black British, 2% Caucasian, 2.1% Chinese, and 6.3% other. Overall, we had 54 patients with SLE and 90 Patients with other connective tissue disorders. Good compliance (81-100%) with MMF therapy was seen in 49 patients, (34%). Poor compliance (0-20%) was seen in 13 patients, (9%). We found a significant correlation between lack of compliance and risk of flares (r= 0.25,p< 0.002), displayed in Figure 1. We also found a significant difference in compliance patters depending on diagnosis and also on age. SLE patients were 34% less compliant with MMF in comparison to other connective tissue disorders. Demographics suggested the degree of compliance increased with age. Patients between 40-69 years of age were 65% more compliant in comparison to the age 20-39 years (p< 0.002).

Conclusion:

SLE and connective tissue disorder patients within Coventry continue to have issues relating to compliance/concordance with MMF treatment and this appears to be worse in patients with SLE and in the 20-39 years of age. These patients also appear to be getting flares hence, this remains a major problem in the management of these conditions.

References:

[1]Gordon C, Amissah-Arthur MB, Gayed M et al. The British Society for Rheumatology guideline for the management of systemic lupus erythematosus in adults. Rheumatol 2017; doi: 10.1093/rheumatology/kex286.

[2]Alsowaida N, Alrasheed M, Mayet A, Alsuwaida A and Omair M A. Medication adherence, depression and disease activity among patients with systemic lupus erythematosus. Lupus 2018,27(2), 327–332. doi:10.1177/0961203317725585.

[3]Chehab G, G M Sauer, J G Richter, R Brinks, R Willers, R Fischer-Betz, B Winkler-Rohlfing, and M Schneider. Medical Adherence in Patients with Systemic Lupus Erythematosus in Germany: Predictors and Reasons for Non-Adherence – a Cross-Sectional Analysis of the LuLa-Cohort.” Lupus (September 2018),1652–60. doi:10.1177/0961203318785245.

Disclosure of Interests:

None declared

Morbidity associated with the immediate vertical rectus abdominus myocutaneous flap reconstruction after radical pelvic surgery

AIM

Patients who undergo radical pelvic surgery often have problems with perineal wound healing and pelvic collections. While there is recognition of the perineal morbidity, there also remains uncertainty around the benefit of vertical rectus abdominus myocutaneous (VRAM) flaps due to the balance between primary healing and the complications associated with this form of reconstruction. This study aimed to evaluate factors associated with significant flap and donor site related complications following VRAM flap reconstruction for radical pelvic surgery.

METHOD

A retrospective analysis of VRAM flap related complications was undertaken from prospectively maintained databases for all patients undergoing radical pelvic surgery (2001- 2017) in two cancer centres.

RESULTS

In all, 154 patients were identified [median age 62 years (range 26-89 years), 80 (52%) men]. Thirty-three (21%) patients experienced significant donor or flap related complications. Major complications (Clavien-Dindo ≥ 3) related to the abdominal donor site occurred in nine (6%) patients, while those related to the flap or perineal site occurred in 28 (18%) patients. Only smoking (P = 0.003) and neoadjuvant radiotherapy (P = 0.047) were associated with the development of significant flap related complications on univariate analysis. Flap related complications resulted in a significantly longer hospital stay (P < 0.001).

CONCLUSION

Careful patient selection is required to balance the risks vs the benefits of VRAM flap reconstruction. Immediate VRAM reconstruction in patients undergoing radical pelvic surgery can achieve early healing and stable perineal closure; it has a low but significant morbidity. Major flap related complications are significantly associated with smoking status and neoadjuvant radiotherapy and result in a prolonged length of hospital stay.

Potential of Bacillus amyloliquefaciens for biocontrol of bacterial canker of tomato incited by Clavibacter michiganensis ssp. michiganensis

A total of 150 rhizobacteria and endorhizobacteria previously isolated from three different horticultural crops; strawberry, apple and apricot were screened for antagonistic activitiy against Clavibacter michiganensis ssp. michiganensis. Among them strain S1, exhibiting significantly higher antagonistic and plant growth promoting ability was characterized as Bacillus amyloliquefaciens based on morphological, biochemical and partial gene sequence analysis of 16S rRNA. B. amyloliquefaciens strain S1 showed maximum growth inhibition of C. michiganensis (12 mm). Moreover, B. amyloliquefaciens strain S1 exhibit significant phosphorus solubilization (94.16 %SEl) and indole acetic acid (27 μg ml^-1) production under in vitro conditions. Antagonistic activity of Bacillus amyloliquefaciens strain S1 was compared with other four strains KU₂S1, R₂S₍₁₎, RG₁₍₃₎ and AG₁₍₇₎ against bacterial canker of tomato under net house conditions. Minimum bacterial canker disease incidence (30.0%) was recorded in B. amyloliquefaciens S1 followed by RG₁₍₃₎ after 30 days of inoculation. The bio-control efficacy was higher in B. amyloliquefaciens S1 treated plants, followed by RG₁₍₃₎.

Quantification and comparison of TLR2 activity in monocyte-derived macrophages of zebu and crossbred cattle

The present study was conducted to quantify and compare TLR2 (toll-like receptor 2) activity in monocyte-derived macrophages of zebu (Tharparkar) and crossbred (Holstein-Friesian × Jersey × Brown Swiss × Hariana) cattle. The cells were either induced with Pam3CSK4 or kept as control. The TLR2 activity was quantified in terms of IκB-α inhibitory subunit (NFKBIA) messenger RNA (mRNA) copies using real-time, one-step reverse transcription-polymerase chain reaction (RT-PCR). Toll-like receptor 2 activity of induced cells was in the range of 1060421 ± 477937 (n=3) to 3514715 ± 290222 (n=3) copies for Tharparkar cattle (n=7) and in the range of 1365532 ± 47243 (n=3) to 3016510 ± 172340 (n=3) copies for the crossbred cattle (n=7). For uninduced cells, this activity was within the range of 117 ± 51 (n=3) to 293 ± 103 (n=3) copies for the Thraparkar cattle (n=7), and in the range of 182 ± 122 (n=3) to 296 ± 88 (n=3) copies for the crossbred cattle (n=7). The TLR2 activity of induced cells in both groups was found to be significantly higher than that of the respective uninduced cells (P<0.0001). Furthermore, upon comparison, TLR2 activities of induced and uninduced cells of the Tharparkar were not found to be significantly different from those of the crossbred cattle (P=0.8154 and P=0.6670). In the present study, we have quantified and compared, for the first time, TLR2 activity in terms of NFKBIA mRNA copies in monocyte-derived macrophages of Tharparkar and crossbred cattle and found that both have equivalent TLR2 activity.

CD48 on blood leukocytes and in serum of asthma patients varies with severity

BACKGROUND

CD48 is a membrane receptor (mCD48) on eosinophils and mast cells and exists in a soluble form (sCD48). CD48 has a pivotal role in murine asthma and in the proinflammatory interactions of mast cells with eosinophils via its ligand CD244. Thus, CD48 might be important in human asthma.

METHODS

Therefore, two separate cohorts (IL and UK) comprising mild, moderate, and severe asthma and healthy volunteers were evaluated for blood leukocyte mCD48 expression and sCD48 in serum. Asthmatic bronchial biopsies were immunostained for CD48. sCD48 effect on CD244-dependent eosinophil activation was evaluated.

RESULTS

Eosinophil mCD48 expression was significantly elevated in moderate while downregulated in severe asthma. mCD48 expression on B, T, and NK cells and monocytes in severe asthma was significantly increased. sCD48 levels were significantly higher in mild while reduced in severe asthma. sCD48 optimal cutoff values for differentiating asthma from health were identified as >1482 pg/ml (IL) and >1619 pg/ml (UK). In asthmatic bronchial biopsies, mCD48 was expressed predominantly by eosinophils. sCD48 inhibited anti-CD244-induced eosinophil activation.

CONCLUSIONS

mCD48 and sCD48 are differentially expressed in the peripheral blood of asthma patients of varying severity. sCD48 inhibits CD244-mediated eosinophil activation. These findings suggest that CD48 may play an important role in human asthma.

Risk factor profiling and study of atherosclerotic coronary plaque burden and morphology with coronary computed tomography angiography in coronary artery disease among young Indians

BACKGROUND

With a decade earlier manifestation of coronary artery disease (CAD) and paucity of data characterizing coronary plaque with coronary computed tomography angiography (CTA) among CAD patients in India, the study aimed to analyze patient characteristics and coronary plaque burden and morphology in young Indian patients with CAD.

METHODS

Serial coronary CTA was performed in 96 CAD patients. Among 60 patients ≤40years, risk factor and coronary plaque analysis done using a 256- slice CT in 33 patients with acute coronary syndrome (ACS) was compared with 27 patients with chronic stable angina (CSA). Univariate and multivariate analysis was performed, for factors predicting ACS as an outcome among young CAD patients. In addition, quantitative and morphologic plaque characteristics were compared among those ≤40years and >40years.

RESULTS

Among 60 subjects ≤40years of age, 77% had dyslipidemia, 70% high lipoprotein(a), 53.33% elevated hs-CRP and 73.33% raised homocysteine. hs-CRP (9.33 vs. 3.33, p value=0.01) and serum triglycerides (178.67 vs. 141.42, p value=0.03) were markedly raised in patients with ACS. Statistically significant number of patients in the ACS group had positive remodelling (ACS, 69.7% vs. CSA, 14.8%; p value<0.001), low attenuation plaque (ACS, 63.6% vs. CSA, 11.1%; p value<0.001), spotty calcification (ACS, 36.4% vs. CSA, 3.7%; p=0.002) and non-calcified plaque (ACS, 69.7% vs. CSA, 11.1%; p<0.001). On multivariate analysis, only lipoprotein (a) >30mg/dL and composite vulnerability score maintained a predictive value for ACS in patients ≤40years. Statistically significant number of patients in the younger age group had higher mean total plaque volume (66.17±41.31mm³ vs. 44.94±49.07mm³; p=0.03), remodelling index (1.5±0.27 vs. 1.08±0.38; p=0.0001). Comparing culprit lesion characteristics of ACS patients in the two age groups, positive remodelling (95.8% vs. 70.5%, p=0.02), spotty calcification (50% vs. 11.7%, p=0.01) and non-calcified plaque (95.8% vs. 70.5%, p=0.02) were significantly more frequent in patients ≤40years.

CONCLUSION

ACS in young Indians is characterized by a higher prevalence of both conventional and newer risk factors. In addition, culprit lesions in young ACS patients are more frequently characterized by coronary plaques with high risk morphological features. This may have implications in terms of preventive strategies to identify this high-risk group.

Interpretation of Post-operative Distal Humerus Radiographs After Internal Fixation: Prediction of Later Loss of Fixation

PURPOSE

Stable fixation of distal humerus fracture fragments is necessary for adequate healing and maintenance of reduction. The purpose of this study was to measure the reliability and accuracy of interpretation of postoperative radiographs to predict which implants will loosen or break after operative treatment of bicolumnar distal humerus fractures. We also addressed agreement among surgeons regarding which fracture fixation will loosen or break and the influence of years in independent practice, location of practice, and so forth.

METHODS

A total of 232 orthopedic residents and surgeons from around the world evaluated 24 anteroposterior and lateral radiographs of distal humerus fractures on a Web-based platform to predict which implants would loosen or break. Agreement among observers was measured using the multi-rater kappa measure.

RESULTS

The sensitivity of prediction of failure of fixation of distal humerus fracture on radiographs was 63%, specificity was 53%, positive predictive value was 36%, the negative predictive value was 78%, and accuracy was 56%. There was fair interobserver agreement (κ = 0.27) regarding predictions of failure of fixation of distal humerus fracture on radiographs. Interobserver variability did not change when assessed for the various subgroups.

CONCLUSIONS

When experienced and skilled surgeons perform fixation of type C distal humerus fracture, the immediate postoperative radiograph is not predictive of fixation failure. Reoperation based on the probability of failure might not be advisable.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

Choline metabolic pathway gene polymorphisms and risk for Down syndrome: An association study in a population with folate-homocysteine metabolic impairment

BACKGROUND/OBJECTIVES

Choline is an essential nutrient involved in one-carbon metabolism, but its role in mechanisms underlying meiotic non-disjunction is poorly known. The relationship between folate-homocysteine metabolic pathway gene polymorphism and Down syndrome (DS) risk has been widely analyzed, but there are limited reports on its correlation with choline metabolism. In the present case-control association study, we investigated the relationship of three single-nucleotide polymorphisms (SNPs) (phosphatidylethanolamine N-methyltransferase (PEMT) rs12325817, choline dehydrogenase (CHDH) rs12676 and homocysteine methyltransferase (BHMT) rs3733890) of choline metabolism with risk for DS.

SUBJECT/METHODS

Genotyping of 228 mothers of a down syndrome child (DSM) and 200 control mothers (CMs) for all SNPs was performed by PCR coupled with restriction fragment length polymorphism method.

RESULTS

A significantly increased risk for BHMT +742AA genotype with an odds ratio of 4.96 (95% confidence interval (CI): 1.66-14.88, P=0.0036) was observed. For PEMT rs12325817 and CHDH rs12676, no significant difference in allelic and genotypic frequencies was observed. In genotypic combination analysis considering PEMT -744GG/CHDH +432GG/BHMT +742GG as the reference combination, PEMT -744GC/CHDH +432GG/BHMT +742GG genotypic combination was significantly higher in DSM compared with that in CMs with an odds ratio of 2.061 (95% CI: 1.10-3.86, P=0.0342). We also observed an epistatic interaction between methylenetetrahydrofolate reductase (MTHFR) rs1801133 and choline metabolic pathway gene variants.

CONCLUSIONS

Our findings indicate impaired choline metabolism showing a greater risk for DS, especially in a population associated with homocysteine-folate impairment. Further studies are required to confirm our findings.

Rapid detection of rifampicin resistance in Mycobacterium tuberculosis by high-resolution melting curve analysis

SETTING

High-resolution melting curve analysis (HRMA) can be used to screen for mutations in genes without the need for specific probes, with low turnaround time and high cost-effectiveness.

OBJECTIVE

To detect the sensitivity and specificity of a line-probe assay (LPA) and HRMA in comparison with BACTEC™ MGIT™ 960 for the detection of rifampicin (RMP) resistance.

DESIGN

A total of 219 Mycobacterium tuberculosis isolates tested by MGIT 960 for RMP susceptibility were tested with HRMA and LPA. Discordant samples were processed for sequencing of the RMP resistance-determining region (RRDR) of the rpoB gene.

RESULTS

HRMA identified 93 of 103 (90.3%) isolates that were resistant and 113/116 (97.4%) that were susceptible on MGIT 960, with a sensitivity and specificity of respectively 90.3% and 97.4%. HRMA identified 117/119 (98.3%) LPA-susceptible and 94/100 (94%) resistant isolates, with 98.3% specificity and 94% sensitivity. Two isolates that were susceptible on LPA but resistant on HRMA showed silent mutations at 539 and 541 codons on sequencing, while 6 isolates that were susceptible on HRMA but resistant on LPA showed D516V (n = 4) and H526C/D (n = 2) mutations. Four isolates (3.9%) that were resistant on MGIT were susceptible on all three genotypic methods, which could be due to mutations outside the RRDR or efflux pumps.

CONCLUSION

HRMA shows good potential as a rapid screening tool for the detection of drug resistance.