From transabdominal to totally extra-peritoneal robotic ventral hernia repair: observations and outcomes

PURPOSE

While robotic-assisted hernia repair has increased the popularity of minimally invasive hernia surgery, selecting between the types of approaches is a challenge for both experts and novices alike. In this study, we compared a single surgeon's early experience transitioning from transabdominal hernia repair with sublay mesh in either the pre-peritoneal or retrorectus space (TA-SM) and enhanced-view totally extra-peritoneal (eTEP) ventral hernia repair in the peri-operative and long-term post-operative time periods.

METHODS

We conducted a retrospective review of 50 eTEP and 108 TA-SM procedures to collect demographics, intraoperative details, and 30-day and 1-year post-operative outcomes. Statistical analysis was performed utilizing Chi-square analysis, Fisher's test, and two sample t-tests with equal variances.

RESULTS

There were no significant differences in patient demographics or comorbidities. eTEP patients had larger defects (109.1 cm² vs. 31.8 cm², p = 0.043) and mesh used (432.8 cm² vs. 137.9 cm², p = 0.001). Operative times were equivalent (158.3 ± 90.6 min eTEP and 155.8 ± 65.2 min TA-SM, p = 0.84), but conversion to alternate procedure type was higher for the transabdominal approach (4% eTEP vs. 22% TA-SM, p < 0.05). Hospital stay was less in the eTEP cohort (1.3 days vs. 2.2 days, p < 0.05). Within 30 days, there were no significant differences in emergency visits or hospital readmissions. There was a greater propensity for eTEP patients to develop seromas (12.0% vs. 1.9%, p < 0.05). At 1 year, there was no statistically significant difference in recurrence rate (4.56% eTEP vs. 12.2% TA-SM, p = 0.28) respective to average time to recurrence (9.17 months eTEP vs. 11.05 months TA-SM).

CONCLUSION

The eTEP approach can be adopted safely and efficiently, and may have superior peri-operative outcomes including fewer conversions and reduced hospital stay.

Identification of a promising inhibitor from Illicium verum (star anise) against the main protease of SARS-CoV-2: insights from the computational study

SARS-CoV-2, the causing agent of coronavirus disease (COVID-19), first broke out in Wuhan and rapidly spread worldwide, resulting in a global health emergency. The lack of specific drugs against the coronavirus has made its spread challenging to control. The main protease (M^pro) is a key enzyme of SARS-CoV-2 used as a key target in drug discovery against the coronavirus. Medicines derived from plant phytoconstituents have been widely exploited to treat various diseases. The present study has evaluated the potential of Illicium verum (star anise) phytoconstituents against M^pro by implementing a computational approach. We performed molecular docking and molecular dynamics simulation study with a set of 60 compounds to identify their potential to inhibit the main protease (M^pro) of SARS-CoV-2. DFT study and post dynamics free energy calculations were also performed to strengthen the findings. The identified four compounds by docking study exhibited the highest potential compared to other selected phytoconstituents. Further, density functional theory (DFT) calculation, molecular dynamics simulation and post dynamics MM-GBSA energy calculation predicted Verimol-G as a potential compound, which formed stable interactions through the catalytic dyad residues. The HOMO orbital energy (-0.250038) from DFT and the post dynamics binding free energy calculation (-73.33 Kcal/mol) correlate, suggesting Verimol-G is the best inhibitor compared to the other phytoconstituents. This compound also complies with the ADME properties of drug likeliness. Thus, based on a computational study, we suggest that Verimol G may be developed as a potential inhibitor against the main protease to combat COVID-19.Communicated by Ramaswamy H. Sarma.

A Comparative Study Of Concurrent Chemo-Radiotherapy With or Without Neoadjuvant Chemotherapy in Treatment of Locally Advanced Non Small Cell Lung Cancer

INTRODUCTION

The standard treatment for unresectable stage III non-small-cell lung cancer (NSCLC) is concurrent chemoradiotherapy. This study was undertaken to evaluate whether induction chemotherapy along with concurrent chemoradiotherapy would result in better tumor control, improved symptom control and any variation in toxicity as compared to concurrent chemoradiotherapy alone.

PATIENTS AND METHODS

Between February 2015 to September 2016, 25 patients each were randomized to control group, in which they received concurrent chemoradiotherapy with weekly cisplatin 40 mg/m2 intravenous, during chest radiotherapy of 66Gy in 33 fractions for 6.5 weeks, and study group, in which patients received three cycles of induction chemotherapy with Cisplatin 75 mg/m2and Paclitaxel 175 mg/m2administered every 21 days followed by identical chemoradiotherapy.

RESULTS

The two groups of patients (with induction vs. without induction chemotherapy) were similar in age, performance status, histology, grade, and stage. At 6thmonth follow-up, complete response was seen in 6 patients in control arm and 7 patients in study arm (?2 = 1.603, p = 0.205) and partial response was seen in 13 and 12 patients in control and study arms respectively (?2 = 1.932, p = 0.165). Symptom control of cough, hemoptysis, chest pain and dyspnoea were also similar in both groups.

DISCUSSION

In our study, no difference in treatment outcome with respect to the two groups was observed, which was similar to studies which have been conducted previously. Radiation is a good modality for symptom control of cough, hemoptysis, chest pain and dyspnoea. In toxicities, pneumonitis and hematological toxicity was slightly higher in study group even at 6th month follow up.

CONCLUSION

Slight increase in toxicity with no added benefit in locoregional tumor control and symptom regression, was seen in patients receiving induction chemotherapy followed by chemoradiotherapy. Concurrent chemoradiotherapy alone can thus be used as only modality of treatment in unresectable stage III NSCLC.

Lactoferrin, a potential iron-chelator as an adjunct treatment for mucormycosis - A comprehensive review

Mucormycosis is a deadly infection which is caused by fungi of the order Mucorales including species belonging to the genus Rhizopus, Mucor, Mycocladus, Rhizomucor, Cunninghamella, and Apophysomyces. Despite antifungal therapy and surgical procedures, the mortality rate of this disease is about 90-100% which is exceptionally high. The hypersensitivity of patients with raised available serum iron indicates that the Mucorales are able to use host iron as a critical factor of virulence. This is because iron happens to be a crucial element playing its role in the growth of cells and development. In this review, we have described Lactoferrin (Lf) as a potential iron-chelator. Lf is a naturally occurring glycoprotein which is expressed in most of the biological fluids. Moreover, Lf possesses exclusive anti-inflammatory effects along with several anti-fungal effects that could prove to be helpful to the pathological physiology of inexorable mucormycosis cases. This literature summarises the biological insights into the Lf being considered as a potential fungistatic agent and an immune regulator. The review also proposes that unique potential of Lf as an iron-chelator can be exploited as the adjunct treatment for mucormycosis infection.

Comparison of peak wall stress and peak wall rupture index in ruptured and asymptomatic intact abdominal aortic aneurysms

BACKGROUND

Previous studies have suggested that finite element analysis (FEA) can estimate the rupture risk of an abdominal aortic aneurysm (AAA); however, the value of biomechanical estimates over measurement of AAA diameter alone remains unclear. This study aimed to compare peak wall stress (PWS) and peak wall rupture index (PWRI) in participants with ruptured and asymptomatic intact AAAs.

METHODS

The reproducibility of semiautomated methods for estimating aortic PWS and PWRI from CT images was assessed. PWS and PWRI were estimated in people with ruptured AAAs and those with asymptomatic intact AAAs matched by orthogonal diameter on a 1 : 2 basis. Spearman's correlation coefficient was used to assess the association between PWS or PWRI and AAA diameter. Independent associations between PWS or PWRI and AAA rupture were identified by means of logistic regression analyses.

RESULTS

Twenty individuals were included in the analysis of reproducibility. The main analysis included 50 patients with an intact AAA and 25 with a ruptured AAA. Median orthogonal diameter was similar in ruptured and intact AAAs (82·3 (i.q.r. 73·5-92·0) versus 81·0 (73·2-92·4) mm respectively; P = 0·906). Median PWS values were 286·8 (220·2-329·6) and 245·8 (215·2-302·3) kPa respectively (P = 0·192). There was no significant difference in PWRI between the two groups (P = 0·982). PWS and PWRI correlated positively with orthogonal diameter (both P < 0·001). Participants with high PWS, but not PWRI, were more likely to have a ruptured AAA after adjusting for potential confounders (odds ratio 5·84, 95 per cent c.i. 1·22 to 27·95; P = 0·027). This association was not maintained in all sensitivity analyses.

CONCLUSION

High aortic PWS had an inconsistent association with greater odds of aneurysm rupture in patients with a large AAA.

Biophysical Characterization of Type III Pantothenate Kinase (PanK) from Acinetobacter baumannii

BACKGROUND

Type-III Pantothenate kinase from the multi drug resistant bacteria, Acinetobacter baumannii (AbPanK) catalyzes the first step of the essential Coenzyme A biosynthesis pathway. AbPanK is an attractive drug target against the bacteria since it is an essential enzyme and its structure is significantly different from the human PanK.

METHODS

AbPanK was cloned, expressed, purified and crystallized. A good quality single crystal was used for X-ray intensity data collection. Dynamic light scattering was done for calculating the hydrodynamic radii and its oligomeric nature in the solution. Binding studies of this protein with its two substrates, Pantothenate and ATP were done using spectrofluorometer.

RESULTS

Our results indicated that AbPanK shows a strong affinity with pantothenate with dissociation constant of 1.2 x 10- 8 M and moderate affinity towards ATP of 3.7x 10-3 M. This fact was further substantiated by the calculations of Km of both substrates using kinase assay kit. Dynamic light scattering studies have shown that it exists as homogenous solution with hydrodynamic radii corresponding to the molecular weight of 29.55 kDa. A low-resolution X-ray intensity data set was collected, which shows that AbPank crystallizes in P2 space group with cell dimensions of a= 165 Å, b= 260 Å, and, c= 197 Å and α= 90.0, β= 113.60, γ= 90.0.

DISCUSSION

Recombinant Pantothenate kinase from Acinetobacter baumannii was purified to homogeneity and crystallized. The enzyme exhibits very low sequence identity (28%) to other corresponding enzymes.

CONCLUSION

The recombinant enzyme was active and its binding affinities with its substrates pantothenate and ATP have been studied. This information would be very useful while designing the inhibitors of this enzyme in order to fight bacterial infections associated to this pathogen.

Emergent robotic versus laparoscopic surgery for perforated gastrojejunal ulcers: a retrospective cohort study of 44 patients

BACKGROUND

Perforated gastrojejunal ulcers are a known complication following Roux-en-Y gastric bypass (RYGB) surgery requiring emergent surgical repair. The robotic approach has not been evaluated for emergency general surgery.

METHODS

A retrospective cohort study from 2015 to 2019 was performed identifying all patients who underwent repair of perforated gastrojejunal ulcers after RYGB at a single institution. Patient characteristics and outcomes were compared by robotic or laparoscopic approach.

RESULTS

Of the 44 patients analyzed, there were 24 robotic and 20 laparoscopic repairs of perforated gastrojejunal ulcers. No patients were initially approached with open surgery. In-room-to-surgery-start time was significantly faster in the robotic group than the laparoscopic group (25 versus 31 min, p = 0.01). Complication rate, complication severity, operating time, hospital length of stay, postoperative vasopressor requirement, discharge to home, hospital length of stay and 30-day readmission were all improved in the robotic group, although these were not statistically significant. Both total inpatient and procedural costs were more in the robotic group than the laparoscopic group.

CONCLUSION

Perforated hollow viscus is not a contraindication for the use of the surgical robot, which may improve outcomes.

Lack of an effective drug therapy for abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) rupture is a common cause of death in adults. Current AAA treatment is by open surgical or endovascular aneurysm repair. Rodent model and human epidemiology, and genetic and observational studies over the last few decades have highlighted the potential of a number of drug therapies, including medications that lower blood pressure, correct dyslipidaemia, or inhibit thrombosis, inflammation or matrix remodelling, as approaches to managing small AAA. This review summarizes prior AAA pathogenesis data from animal and human studies aimed at identifying targets for the development of drug therapies. The review also systematically assesses past randomized placebo-controlled drug trials in patients with small AAAs. Eleven previously published randomized-controlled clinical trials testing different drug therapies aimed at slowing AAA progression were identified. Five of the trials tested antibiotics and three trials assessed medications that lower blood pressure. Meta-analyses of these trials suggested that neither of these approaches limit AAA growth. Allocation to blood pressure-lowering medication was associated with a small reduction in AAA rupture or repair, compared to placebo (relative risk 0.94, 95% confidence intervals 0.89, 1.00, P = 0.047). Three further trials assessed the effect of a mast cell inhibitor, fibrate or platelet aggregation inhibition and reported no effect on AAA growth or clinical events. Past trials were noted to have a number of design issues, particularly small sample sizes and limited follow-up. Much larger trials are needed to properly test potential therapeutic approaches if a convincingly effective medical therapy for AAA is to be identified.

Studying land use dynamics using decadal satellite images and Dyna-CLUE model in the Mahanadi River basin, India

Population growth rate indicates the proportional rate of settlement expansion and landscape modification in any river basin. The Mahanadi River basin (MRB), which is a densely populated, cropland and forest-dominated landscape, is selected as a case study area for studying the nature of built-up expansion and the corresponding land cover modifications. Satellite data-derived land use/land cover (LU/LC) maps for the years 1995, 2005, and 2015 were used for identification of landscape changes during the past three decades. One of the major LU/LC changes are observed in terms of increase in the water, which may be attributed to construction of new dams at the cost of the croplands and forest areas. Conversion of forest to cropland and expansion and densification of built-up areas in and around the existing built-up areas are also identified as a major LU/LC change. The geostatistical analysis was performed to identify the relationship between LU/LC classes with drivers, which showed that built-up areas were more in topographically flat terrain with higher soil depth, and expanded more around the existing built-up areas; cropland areas were more at lower elevation and less sloppy terrain, and forest areas were more at higher elevation. The LU/LC scenario of 2025 was projected using a spatially explicit dynamic conversion of land use and its effects (Dyna-CLUE) modeling platform with the LU/LC change trends of past 10 years (2005-2015) and 20 years (1995-2015). The major LU/LC changes observed during 2005-2015 were built-up expansion by 36.53% and deciduous forest and cropland reduction by 0.35% and 0.45%, respectively. Thus, the corresponding predicted change during 2015-2025 estimated built-up expansion by 25.70% and deciduous forest and croplands loss by 0.43% and 0.35%, respectively. On the other hand, during 1995 to 2015, the total built-up expansion and deciduous forest and cropland reduction were observed 50.79%, 0.45%, and 0.73%, respectively. Thus, the predicted changes during 2015-2025 were estimated as 18.48% built-up expansion and 0.22% and 0.21% deciduous forest and cropland loss. However, with the conditions of restricted deforestation and less landscape modification, the LU/LC projections show less built-up area expansion, reducing the cropland, fallow land, plantation, and waste land. The reduced numbers of land cover conversions types during 2005-2015 compared with 1995-2005 indicate more stabilized landscape. The input LU/LC maps and statistical analysis demonstrated the landscape modifications and causes observed in the basin. The model projected LU/LC maps are giving insights to possible changes under multiple pathways, which will help the agriculture, forest, urban, and water resource planners and managers in improved policy-making processes.

Structural and biochemical studies of phosphopantetheine adenylyltransferase from Acinetobacter baumannii with dephospho-coenzyme A and coenzyme A

Phosphopantetheine adenylyl transferase catalyzes a rate limiting penultimate step of the multistep reaction which produces coenzyme A (CoA) as a final product. CoA is required as an essential cofactor in a number of metabolic reactions. Therefore inhibiting the function of this enzyme will lead to cell death in bacteria. Acinetobacter baumannii is multi drug resistant pathogen and causes infections in immunocompromised patients. AbPPAT has been cloned, expressed, purified and crystallized and structures of two complexes of AbPPAT with dephospho coenzyme A (dPCoA) and coenzyme A (CoA) have been determined. Both dPCoA and CoA molecules are observed in the substrate binding site of AbPPAT. A comparison with the structures of the complexes of PPAT from other species shows that the orientations of dPCoA are identical in all the structures. On the other hand, as observed from the structures of the complexes of CoA with PPAT, the orientations of CoA are found to differ considerably. This shows that the substrates occupy identical positions in the substrate binding sites of enzymes whereas the positions of inhibitors may differ. The binding studies carried out using fluorescence method and surface plasmon resonance techniques showed that binding affinity of CoA towards AbPPAT is nearly three times higher than that of dPCoA.

Systematic review and meta-analysis of clinical trials examining the effect of hyperbaric oxygen therapy in people with diabetes-related lower limb ulcers

AIM

To examine the efficacy of hyperbaric oxygen therapy in healing diabetes-related lower limb ulcers through a meta-analysis of randomized clinical trials.

METHODS

A literature search was conducted to identify appropriate clinical trials. Inclusion required randomized study design and reporting of the proportion of diabetes-related lower limb ulcers that healed. A meta-analysis was performed to examine the effect of hyperbaric oxygen therapy on ulcer healing. The secondary outcomes were minor and major amputations.

RESULTS

Nine randomized trials involving 585 participants were included. People allocated to hyperbaric oxygen therapy were more likely to have complete ulcer healing (relative risk 1.95, 95% CI 1.51-2.52; P<0.001), and less likely to require major (relative risk 0.54, 95% CI 0.36-0.81; P=0.003) or minor (relative risk 0.68, 95% CI 0.48-0.98; P=0.040) amputations than control groups. Sensitivity analyses suggested the findings were dependent on the inclusion of one trial. Adverse events included ear barotrauma and a seizure. Many of the trials were noted to have methodological weaknesses including absence of blinding of outcome assessors, lack of a justifiable sample size calculation and limited follow-up.

CONCLUSIONS

This meta-analysis suggests hyperbaric oxygen therapy improves the healing of diabetes-related lower limb ulcers and reduces the requirement for amputation. Confidence in these results is limited by significant design weaknesses of previous trials and inconsistent findings. A more rigorous assessment of the efficacy of hyperbaric the efficacy of hyperbaric oxygen therapy is needed.

Inhibition of human 3-hydroxy-3-methylglutaryl CoA reductase by peptides leading to cholesterol homeostasis through SREBP2 pathway in HepG2 cells

In mammalian cells, human 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), a rate-limiting endoplasmic reticulum (ER) bonded enzyme, plays a central role in the cholesterol homeostasis via the negative feedback mechanism. The present study indicates that the interactions of novel peptides with the catalytic domain of HMGCR, provides an alternative therapeutic candidate for reducing cholesterol. The potential natural origin of HMGCR peptide inhibitors were filtered from the peptide library using the molecular docking, which revealed three strong candidates for inhibition. This information was used for synthesizing peptides, which were evaluated for inhibition against HMGCR. The stronger docking interactions were confirmed by experimental dissociation constant (K_D) values of 9.1 × 10^-9 M, 1.4 × 10^-8 M and 1.2 × 10^-8 M for peptides NALEPDNRIESEGG (Pep-1), NALEPDNRIES (Pep-2) and PFVKSEPIPETNNE (Pep-3) respectively. The immunological based interactions show a strong evidence of peptide-HMGCR complexes. The LDL uptake showed enhancements after treatments with peptides in the extracellular environment of HepG2 cells, which was further, corroborated through increase in the immunofluorescence signal of the localized LDL-R protein expression on the cell membrane. The results showed that the mRNA and protein expression of transcription factors were significantly up-regulated showing regulation of cholesterol biosynthesis in peptide treated HepG2 cells. The binding of transcription factors, sterol regulatory element (SRE) and cAMP-response element (CRE) on HMGCR promotor further confirms the cholesterol biosynthesis regulation. All the above results suggested a key role of peptide/s in alleviating cholesterol accumulation in tissue via inhibition of rate-limiting HMGCR enzyme.

Meta-analysis of clinical trials examining the benefit of structured home exercise in patients with peripheral artery disease

Background

Supervised exercise is recommended for the management of peripheral artery disease (PAD); however, the uptake is limited. Structured home exercise programmes may be more feasible, but their effectiveness is unclear. This systematic review and meta-analysis examined the benefit of structured home exercise programmes for treating PAD in comparison to controls not receiving an exercise programme.

Methods

A literature search was conducted to identify RCTs comparing structured home exercise with controls not receiving an exercise programme among patients with PAD. To be included, studies had to report outcomes from treadmill or corridor walking tests, or objective assessment of physical activity. Inverse variance-weighted meta-analysis was performed to compare changes in maximum walking distance and intermittent claudication onset distance in treadmill tests, walking distance during a 6-min walking test, and physical activity measured using a pedometer or accelerometer. Summarized results are presented in terms of standard deviation differences.

Results

Eleven randomized trials involving 807 patients were included. Follow-up ranged from 2 to 24 months; only one trial included follow-up beyond 12 months. Meta-analyses showed that structured home exercise programmes led to significant improvements in maximum walking distance (mean difference (MD) 0·32, 95 per cent c.i. 0·15 to 0·50; P &lt; 0·001), intermittent claudication onset distance (MD 0·45, 0·27 to 0·62; P &lt; 0·001), walking distance in a 6-min walking test (MD 0·28, 0·09 to 0·47; P = 0·004) and physical activity (MD 0·27, 0·11 to 0·43; P = 0·001).

Conclusion

This meta-analysis suggests that structured home exercise programmes are effective at improving walking performance and physical activity in the short term for patients with PAD.

Systematic Review and Meta-Analysis of the Association Between C-Reactive Protein and Major Cardiovascular Events in Patients with Peripheral Artery Disease

BACKGROUND

Patients with peripheral artery disease (PAD) are at substantial risk of cardiovascular events. There is interest in using blood markers, such as C-reactive protein (CRP), to monitor prognosis and treatment efficacy in PAD patients. The aim of this meta-analysis was to assess the association between CRP and major cardiovascular events in PAD patients.

METHOD

Studies evaluating the association between CRP and major cardiovascular events (myocardial infarction, stroke, cardiac revascularisation and mortality) were identified using MEDLINE and the Cochrane library. Studies that did not include participants with PAD, measure CRP, or follow-up patients for cardiovascular events were excluded. Meta-analyses of published adjusted hazard ratios (HR) were conducted using an inverse variance-weighted random effects model, and heterogeneity was assessed with the I² index.

RESULTS

A total of 16 studies involving 5041 participants met the inclusion criteria for the systematic review. Eight studies were included in the meta-analyses. Summary effect estimates were reported as HR comparing higher and lower quantiles, and HR per unit increase in log_eCRP. PAD patients with higher CRP had a significantly greater risk of major cardiovascular events compared with those with lower CRP (HR 2.26, 95% CI 1.65-3.09, p < 0.001). The HR for major cardiovascular events was 1.38 (95% CI 1.16-1.63, p < 0.001) per unit increase in log_eCRP.

CONCLUSIONS

The present findings suggest that high circulating CRP is predictive of major cardiovascular events in PAD patients.

Assessment and validation of a novel angiographic scoring system for peripheral artery disease

BACKGROUND

Angiography is used routinely in the assessment of lower-limb arteries, but there are few well validated angiographic scoring systems. The aim of this study was to develop and validate a novel angiographic scoring system for peripheral artery disease.

METHODS

An angiographic scoring system (the ANGIO score) was developed and applied to a sample of patients from a single vascular surgical department who underwent CT angiography of the lower limbs. The reproducibility of the ANGIO score was compared with those of the Bollinger and Trans-Atlantic inter-Society Consensus (TASC) IIb systems in a series of randomly selected patients. Associations between the ANGIO score and lower-limb ischaemia, as measured by the ankle : brachial pressure index (ABPI), and outcome events (major lower-limb amputations and cardiovascular events - myocardial infarction, stroke and cardiovascular death) were assessed.

RESULTS

Some 256 patients undergoing CT angiography were included. The interobserver reproducibility of the ANGIO score was better than that of the other scoring systems examined (κ = 0·90, P = 0·002). There was a negative correlation between the ANGIO score and ABPI (ρ = -0·33, P = 0·008). A higher ANGIO score was associated with an increased risk of major lower-limb amputation (hazard ratio (HR) for highest versus lowest tertile 9·30, 95 per cent c.i. 1·95 to 44·38; P = 0·005) and cardiovascular events (HR 2·73, 1·31 to 5·70; P = 0·007) following adjustment for established risk factors.

CONCLUSION

The ANGIO score provided a reproducible and valid assessment of the severity of lower-limb ischaemia and risk of major amputation and cardiovascular events in these patients with peripheral artery disease.

Probiotic and functional characterization of bifidobacteria of Indian human origin

AIMS

To identify and characterize the probiotic and functional attributes of bifidobacteria isolated from human sources by in vitro methods.

METHODS AND RESULTS

Twelve isolates of bifidobacteria were obtained from different human sources viz; human milk, infant and adult faeces. The preliminary identification of isolates was done using genus-specific PCR followed by species level identification using 16S rRNA sequencing. All the isolates invariably showed potential probiotic characteristics. Finally, three most promising isolates were subjected to safety evaluation and were found to be safe. These were further evaluated for their potential functional characteristics like, antioxidative, antimutagenic and cholesterol assimilation. The isolates viz; NBIF-5 (73·55 ± 0·03%) and NBIF-7 (64·06 ± 0·03%) assimilated significantly higher cholesterol than NBIF-2. The maximum antioxidative activity was observed in NBIF-2 (56·56 ± 0·28% of radical inhibition). High percentage antimutagenicity scores of 52·41 ± 2·25% and 53·68 ± 1·98% against sodium azide (NaN3) were shown by NBIF-2 and NBIF-7 respectively.

CONCLUSIONS

Three strains (NBIF-2, NBIF-5 and NBIF-7) were found to be endowed with appreciable probiotic and functional activities.

SIGNIFICANCE AND IMPACT OF THE STUDY

With growing demands for probioitcs and bifidobacteria being prominent ones, new strains of diversified origin have the potential to be explored for commercial and functional applications and thus can be added to the existing commercially available strains of this genera.

Robotic Single- and Multisite Cholecystectomy in Children

BACKGROUND

Elective cholecystectomy is a high-volume, simple procedure, well suited for the development of a pediatric robotic surgery program. Surgical robot software, by "reversing" the surgeon's hands, simplifies single-site cholecystectomy through a single incision at the umbilicus.

MATERIALS AND METHODS

Data were reviewed on the first nine children who had robotic cholecystectomy, with the Da Vinci® Surgical System (Intuitive Surgical Inc., Sunnyvale, CA) device, at our institution. All cases were performed by a single surgeon, proctored by an experienced robotic general surgeon.

RESULTS

There were 9 patients: the first 4 patients had robotic multiport cholecystectomy, and the last 5 had robotic single-site cholecystectomy. Eight were girls. They were 10-18 years of age (median, 14 years). Diagnoses were biliary dyskinesia (n = 5) and symptomatic cholelithiasis (n = 4). Median body mass index was 24.9 (range, 20.2-43.8) kg/m(2). Median anesthesia time for multiport cholecystectomy was 139 (range, 120-162) minutes; median anesthesia time for single-site cholecystectomy was 169 (range 122-180) minutes. Median console time for multiport cholecystectomy was 47 (range, 44-58) minutes; median console time for single-site cholecystectomy was 69 (range, 66-86) minutes. Eight of the 9 patients went home on the day of surgery, and 1 stayed overnight. Patients were seen at 13-20 days after surgery (median, 14 days). There were no complications. There were no conversions to open surgery and none from single-site to multiport surgery.

CONCLUSIONS

Robotic cholecystectomy is safe and efficacious and is a suitable introductory procedure for pediatric surgeons considering a robotic surgery program. Single-site robotic cholecystectomy is a cosmetically attractive option but takes longer than multiport robotic cholecystectomy.

Long-Term Follow-Up Results following Elective Treatment of Unruptured Intracranial Aneurysms with the Pipeline Embolization Device

BACKGROUND AND PURPOSE

Numerous reports of treatment of wide-neck aneurysms by flow diverters have been published; however, long-term outcomes remain uncertain. This article reports the imaging results of unruptured aneurysms treated electively with the Pipeline Embolization Device for up to 56 months and clinical results for up to 61 months.

MATERIALS AND METHODS

One hundred nineteen aneurysms in 98 patients from 3 centers admitted between August 2009 and June 2011 were followed at 6-month, 1-year, and 2+-year postprocedural timeframes. Analyses on the effects of incorporated vessels, previous stent placement, aneurysm size, and morphology on aneurysm occlusion were performed.

RESULTS

The 1- and 2+-year imaging follow-ups were performed, on average, 13 and 28 months postprocedure. At 2+-year follow-up, clinical data were 100% complete and imaging data were complete for 103/116 aneurysms (88.8%) with a 93.2% occlusion rate. From 0 to 6 months, TIA, minor stroke, and major stroke rates were 4.2%, 3.4%, and 0.8% respectively. After 6 months, 1 patient had a TIA of uncertain cause, with an overall Pipeline Embolization Device-related mortality rate of 0.8%. An incorporated vessel was significant for a delay in occlusion (P = .009) and nonocclusion at 6 months and 1 year, with a delayed mean time of occlusion from 9.1 months (95% CI, 7.1-11.1 months) to 16.7 months (95% CI, 11.4-22.0 months). Other factors were nonsignificant.

CONCLUSIONS

The Pipeline Embolization Device demonstrates continued very high closure rates at 2+ years, with few delayed clinical adverse sequelae. The presence of an incorporated vessel in the wall of the aneurysm causes a delay in occlusion that approaches sidewall closure rates by 2 years.

Mode of binding of the antithyroid drug propylthiouracil to mammalian haem peroxidases

The mammalian haem peroxidase superfamily consists of myeloperoxidase (MPO), lactoperoxidase (LPO), eosinophil peroxidase (EPO) and thyroid peroxidase (TPO). These enzymes catalyze a number of oxidative reactions of inorganic substrates such as Cl(-), Br(-), I(-) and SCN(-) as well as of various organic aromatic compounds. To date, only structures of MPO and LPO are known. The substrate-binding sites in these enzymes are located on the distal haem side. Propylthiouracil (PTU) is a potent antithyroid drug that acts by inhibiting the function of TPO. It has also been shown to inhibit the action of LPO. However, its mode of binding to mammalian haem peroxidases is not yet known. In order to determine the mode of its binding to peroxidases, the structure of the complex of LPO with PTU has been determined. It showed that PTU binds to LPO in the substrate-binding site on the distal haem side. The IC50 values for the inhibition of LPO and TPO by PTU are 47 and 30 µM, respectively. A comparision of the residues surrounding the substrate-binding site on the distal haem side in LPO with those in TPO showed that all of the residues were identical except for Ala114 (LPO numbering scheme), which is replaced by Thr205 (TPO numbering scheme) in TPO. A threonine residue in place of alanine in the substrate-binding site may affect the affinity of PTU for peroxidases.

Role of multivitamins, micronutrients and probiotics supplementation in management of HIV infected children

OBJECTIVES

To assess the immuno-clinical response of micronutrients supplementation in human immunodeficiency virus (HIV) infected children (both on and without antiretroviral therapy) and to assess the role of probiotics in improvement of CD4 counts in HIV infected children not on antiretroviral therapy.

METHODS

This was an open labeled randomized control study, conducted in Department of Pediatrics and Antiretrovial Therapy (ART) Center, S.N. Medical College, Agra. One hundred and twenty seven HIV infected children aged ≤ 15 y were included in the study. Enrolled children were randomized to receive micronutrients for 6 mo or probiotics for 3 mo. Children who did not receive supplements served as control. Change in WHO clinical stage, immunological stage, CD4 counts and body mass index (BMI) status were taken at the end of 6 mo. In probiotic group, mean CD4 count were taken as outcome measure. A detailed history, examination and WHO clinical staging were recorded for all the patients.

RESULTS

In micronutrient supplemented group (not on ART), significant improvement was seen in WHO clinical staging (p = 0.049) when compared to controls after 6 mo. Probiotic supplemented group showed significant increase in CD4 counts compared to control group (p = 0.0022) in children >5 y. Control group showed significant decline in CD4 count in children ≤5 y (-65.3 cells/mm(3), p=0.005) and in children >5 y (-87.9 cells/mm(3), p=0.05) after 12 wk of supplementation.

CONCLUSIONS

Probiotics supplementation has shown significant improvement in CD4 counts. Micronutrients supplementation has shown significant delay in the progression towards advance stage of disease.

Association of Superoxide dismutases (SOD1 and SOD2) and Glutathione peroxidase 1 (GPx1) gene polymorphisms with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a metabolic disorder resulting from oxidative stress (OS), the root cause of insulin resistance, β-cell dysfunction, and impaired glucose tolerance. Antioxidant enzymes play key roles in cellular defense and can be used as important biomarkers for T2DM. The present study was undertaken to evaluate three genetic polymorphisms viz. SOD1 + 35A/C, SOD2 + 47C/T, and GPx + 599C/T in 207 T2DM cases and 210 healthy controls from North India. DNA was extracted from blood samples and genotyping was done by PCR-RFLP. Genotypic/allelic frequencies and haplotype/gene-gene interaction analysis were performed using SPSS (version 15.0) and SHEsis (v. online). Except age, all other biochemical parameters showed highly significant association in T2DM cases (P < 0.001). In North Indian population, SOD1 + 35A/C variant was monomorphic. Genotype/allele frequencies of SOD2 + 47C/T polymorphism and carriage rate of 'C' allele showed significant association (p < 0.05, < 0.001; OR 2.434). Genotype/allele frequencies of GPx1 + 599C/T and carriage rate showed no association although the odds ratio of GPx1 'C' allele indicated a 1.362 times higher risk of T2DM. SOD2 'CT' and GPx1 'CC' genotypes showed maximum association with biochemical parameters. Haplotype/gene-gene interaction analysis in controls and cases showed that SOD2 + 47C/T and GPx1 + 599C/T were in linkage disequilibrium (D: 0.168; r(2): 0.10) and individuals with this combination had a 1.273 times higher risk [OR; CI (95%)] of developing T2DM. Thus, we conclude that it is essential to assess the combinatorial association of gene variants with T2DM in order to identify risk haplotypes in a population.

Crystal structure of peptidyl-tRNA hydrolase from a Gram-positive bacterium, Streptococcus pyogenes at 2.19 Å resolution shows the closed structure of the substrate-binding cleft

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Structure of peptidyl-tRNA hydrolase (Pth) from Streptococcus pyogenes.

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First structure of Pth from a Gram-positive bacterium.

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Conformations of the lid and gate loops are different from those observed in other Pth enzymes.

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The substrate-binding channel is closed at both sites of the lid and gate loops.

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In Pth structures from other species, the channel is fully open at the lid loop.

Peptidyl-tRNA hydrolase (Pth) catalyses the release of tRNA and peptide components from peptidyl-tRNA molecules. Pth from a Gram-positive bacterium Streptococcus pyogenes (SpPth) was cloned, expressed, purified and crystallised. Three-dimensional structure of SpPth was determined by X-ray crystallography at 2.19 Å resolution. Structure determination showed that the asymmetric unit of the unit cell contained two crystallographically independent molecules, designated A and B. The superimposition of C^α traces of molecules A and B showed an r.m.s. shift of 0.4 Å, indicating that the structures of two crystallographically independent molecules were identical. The polypeptide chain of SpPth adopted an overall α/β conformation. The substrate-binding cleft in SpPth is formed with three loops: the gate loop, Ile91–Leu102; the base loop, Gly108–Gly115; and the lid loop, Gly136–Gly150. Unlike in the structures of Pth from Gram-negative bacteria, the entry to the cleft in the structure of SpPth appeared to be virtually closed. However, the conformations of the active site residues were found to be similar.

Long-term quality of life after living kidney donation

BACKGROUND

The supply of deceased donor kidneys available for transplantation is not sufficient to meet the demand. Despite a low rate of complications for donors and superior outcomes for recipients, living kidney donation (LKD) is on the decline for reasons that remain unclear.

METHODS

We performed a retrospective review and analysis of living kidney donors (LDs) who underwent donor nephrectomy between January 1, 2000 and December 31, 2010. Candidates who were excluded from LKD were identified as control subjects (CSs). LDs and CSs were invited to voluntarily undergo a quality of life assessment using Short Form 12 v1.0 Questionnaire (SF-12) and an addendum questionnaire (AQ). The SF-12 and AQ were administered by telephone. Statistical analysis of the results was performed to obtain the SF-12 physical component score (PCS), SF-12 mental component score (MCS), and the AQ score. PCS and MCS for the general population were obtained from the 1998 National Survey of Functional Health Status.

RESULTS

During the study period, 83 LDs and 116 CSs were interviewed. LDs were noted to have higher PCS (54.1 vs 49.6) and MCS (55.7 vs 49.4) compared with the general population. Ninety-nine percent of LDs believed that their quality of life did not decrease after LKD; 21.7% reported experiencing complications. Half of the LDs (48%) reported missing 1 day of work for evaluation; 71% of LDs reported missing at least 4 weeks of work after LKD. Nearly all LDs (99%) would undergo donation again. Fifty-two percent of LDs reported adhering to the recommended 2-year follow-up schedule with the transplantation team; 87% of LDs reported seeing their primary care physician.

CONCLUSION

LDs are physically and mentally healthier after LKD compared to the general population. Most donors miss at least 1 month of work for LKD and undergo some form of post-donation monitoring. Despite this commitment, LKD is a very satisfying experience.

Occurrence of complications in newly diagnosed type 2 diabetes patients: a hospital based study

Type 2 diabetes is characterised by a long asymptomatic period of hyperglycaemia and many individuals with type 2 diabetes have complications even at the time of diagnosis. The purpose of present study was to study and compare the prevalence of complications at the time of diagnosis of type 2 diabetes in newly diagnosed asymptomatic and symptomatic patients. One hundred and five consecutive newly diagnosed cases of type 2 diabetes were selected for study based on fasting blood glucose level > or = 126 mg/dl. Individuals who were known diabetic, individuals presenting with acute complications were excluded from study. The prevalence rates of various complications in newly diagnosed diabetic patients were studied in both asymptomatic and symptomatic subjects and results were analysed statistically using test of proportion and Chi-square test. There were 40.95% of newly diagnosed diabetes patients who were asymptomatic. There was no significant difference between those having symptoms of diabetes and those without symptoms of diabetes with regard to age, sex, weight and hypertension. Occurrence of both microvascular and macrovascular complications were not different in the two groups studied. We also observed a very high prevalence of microvascular (32.55%) complications in asymptomatic newly diagnosed type 2 diabetes patients. Since 35.20% of cases in this study were below 50 years and various complications develop 10-20 years after onset of disease, this study suggests that screening for diabetes should commence at the age of 40 years in general population.

Safety of the pipeline embolization device in treatment of posterior circulation aneurysms

BACKGROUND AND PURPOSE

The published results of treating internal carotid artery aneurysms with the PED do not necessarily apply to its use in the posterior circulation because disabling brain stem infarcts can be caused by occlusion of a single perforator. In this multicenter study, we assessed the safety of PED placement in the posterior circulation.

MATERIALS AND METHODS

A prospective case registry was maintained of all posterior circulation aneurysms treated with PEDs at 3 Australian neurointerventional centers during a 27-month period. The objective was to assess the complications and aneurysm occlusion rates associated with posterior circulation PEDs.

RESULTS

Thirty-two posterior circulation aneurysms were treated in 32 patients. No deaths or poor neurologic outcomes occurred. Perforator territory infarctions occurred in 3 (14%) of the 21 patients with basilar artery aneurysms, and in all 3, a single PED was used. Two asymptomatic intracranial hematomas were recorded. No aneurysm rupture or PED thrombosis was encountered. The overall rate of permanent neurologic complications was 9.4% (3/32); all 3 patients had very mild residual symptoms and a good clinical outcome. Aneurysm occlusion was demonstrated in 85% of patients with >6 months of follow-up and 96% of patients with >1 year of follow-up.

CONCLUSIONS

The PED is effective in the treatment of posterior circulation aneurysms that are otherwise difficult or impossible to treat with standard endovascular or surgical techniques, and its safety is similar to that of stent-assisted coiling techniques. A higher clinical perforator infarction rate may be associated with basilar artery PEDs relative to the internal carotid artery.

A risk-prediction model for in-hospital mortality after heart transplantation in US children

We sought to develop and validate a quantitative risk-prediction model for predicting the risk of posttransplant in-hospital mortality in pediatric heart transplantation (HT). Children <18 years of age who underwent primary HT in the United States during 1999-2008 (n = 2707) were identified using Organ Procurement and Transplant Network data. A risk-prediction model was developed using two-thirds of the cohort (random sample), internally validated in the remaining one-third, and independently validated in a cohort of 338 children transplanted during 2009-2010. The best predictive model had four categorical variables: hemodynamic support (ECMO, ventilator support, VAD support vs. medical therapy), cardiac diagnosis (repaired congenital heart disease [CHD], unrepaired CHD vs. cardiomyopathy), renal dysfunction (severe, mild-moderate vs. normal) and total bilirubin (≥ 2.0, 0.6 to <2.0 vs. <0.6 mg/dL). The C-statistic (0.78) and the Hosmer-Lemeshow goodness-of-fit (p = 0.89) in the model-development cohort were replicated in the internal validation and independent validation cohorts (C-statistic 0.75, 0.81 and the Hosmer-Lemeshow goodness-of-fit p = 0.49, 0.53, respectively) suggesting acceptable prediction for posttransplant in-hospital mortality. We conclude that this risk-prediction model using four factors at the time of transplant has good prediction characteristics for posttransplant in-hospital mortality in children and may be useful to guide decision-making around patient listing for transplant and timing of mechanical support.

Crystal structure of peptidyl-tRNA hydrolase from mycobacterium smegmatis reveals novel features related to enzyme dynamics

Peptidyl-tRNA hydrolase from Mycobacterium smegmatis is a single domain 21 kDa protein involved in the hydrolysis of prematurely produced peptidyl-tRNAs to ensure the viability of cells in bacteria, thus making it a potentially important drug target. In order to aid the development of potent drugs for controlling bacterial infections, the three-dimensional structure of peptidyl-tRNA hydrolase from Mycobacterium smegmatis has been determined. The protein adopts a compact α/β globular fold with a twisted β-sheet surrounded by α-helices. The functionally important C-terminal stretch has been unambiguously modeled for the first time in the unliganded structure of peptidyl-tRNA hydrolase. The segment, Gly138 - Val150 is mobile because it lacks significant interactions with the rest of the protein molecule. This conformational flexibility is reflected through different values of distances between a reference atom Ala147 C(α) of the segment Gly138 - Val150 to Gly114 C(α) from another segment from opposite side of the substrate binding channel in Mycobacterium smegmatis (7.8 Ǻ), Mycobacterium tuberculosis (9.5 Ǻ) and Escherichia coli (11.8 Ǻ). Similarly, the conformation of loop Gly109 - Gly117 with respect to another loop Asp95 - Asp100 also shows variability of the substrate binding cleft as the distance between Asp98 O(δ2) to Gly113 C(α) in Mycobacterium smegmatis is 4.5 Ǻ while the corresponding distances in Mycobacterium tuberculosis and Escherichia coli are 3.1 Ǻ and 6.7 Ǻ respectively. The hydrogen bonded interactions between Asn116, His22 and Asp95 indicate a stereochemically favorable arrangement of these residues for catalytic action.

Trends in wait-list mortality in children listed for heart transplantation in the United States: era effect across racial/ethnic groups

We sought to evaluate trends in overall and race-specific pediatric heart transplant (HT) wait-list mortality in the United States (US) during the last 20 years. We identified all children <18 years old listed for primary HT in the US during 1989-2009 (N = 8096, 62% White, 19% Black, 13% Hispanic and 6% Other) using the Organ Procurement and Transplant Network database. Wait-list mortality was assessed in four successive eras (1989-1994, 1995-1999, 2000-2004 and 2005-2009). Overall wait-list mortality declined in successive eras (26%, 23%, 18% and 13%, respectively). The decline across eras remained significant in adjusted analysis (hazard ratio [HR] 0.70 in successive eras, 95% confidence interval [CI], 0.67-0.74) and was 67% lower for children listed during 2005-2009 versus those listed during 1989-1994 (HR 0.33; CI, 0.28-0.39). In models stratified by race, wait-list mortality decreased in all racial groups in successive eras. In models stratified by era, minority children were not at higher risk of wait-list mortality in the most recent era. We conclude that the risk of wait-list mortality among US children listed for HT has decreased by two-thirds during the last 20 years. Racial gaps in wait-list mortality present variably in the past are not present in the current era.

Endovascular treatment using predominantly stent-assisted coil embolization and antiplatelet and anticoagulation management of ruptured blood blister-like aneurysms

BACKGROUND AND PURPOSE

BBA is a rare type of intracranial aneurysm that is difficult to treat both surgically and endovascularly and is often associated with a high degree of morbidity/mortality. The aim of this study was to present clinical and angiographic results, as well as antiplatelet/anticoagulation regimens, of endovascular BBA treatment by using predominantly stent-assisted coil embolization.

MATERIALS AND METHODS

Thirteen patients (men/women, 6/7; mean age, 49.3 years) with ruptured BBAs were included from 2 different institutions. Angiographic findings, treatment strategies, anticoagulation/antiplatelet protocols, and clinical (mRS) and angiographic outcome were retrospectively analyzed.

RESULTS

Eleven BBAs were located in the supraclinoid ICA, and 2 on the basilar artery trunk. Nine of 13 were ≤3 mm in the largest diameter, and 8/13 showed early growth before treatment. Primary stent-assisted coiling was performed in 11/13 patients, double stents and PAO in 1 patient, each. Early complementary treatment was required in 3 patients, including PAO in 2. In stent-placement procedures, altered periprocedural antiplatelet (11/12) and postprocedural heparin (6/12) protocols were used without evidence of thromboembolic events. Two patients had early rehemorrhage, including 1 major fatal SAH. Twelve of 13 BBAs showed complete or progressive occlusion at late angiographic follow-up. Clinical midterm outcome was good (mRS scores, 0-2) in 12/13 patients.

CONCLUSIONS

Stent-assisted coiling of ruptured BBAs is technically challenging but can be done with good midterm results. Reduced periprocedural and postprocedural antiplatelet/anticoagulation protocols may be used with a low reasonable risk of thromboembolic complications. However, regrowth/rerupture remains a problem underlining the importance of early angiographic follow-up and re-treatment, including PAO if necessary.

Association of race and socioeconomic position with outcomes in pediatric heart transplant recipients

We assessed the association of socioeconomic (SE) position with graft loss in a multicenter cohort of pediatric heart transplant (HT) recipients. We extracted six SE variables from the US Census 2000 database for the neighborhood of residence of 490 children who underwent their primary HT at participating transplant centers. A composite SE score was derived for each child and four groups (quartiles) compared for graft loss (death or retransplant). Graft loss occurred in 152 children (122 deaths, 30 retransplant). In adjusted analysis, graft loss during the first posttransplant year had a borderline association with the highest SE quartile (HR 1.94, p = 0.05) but not with race. Among 1-year survivors, both black race (HR 1.81, p = 0.02) and the lowest SE quartile (HR 1.77, p = 0.01) predicted subsequent graft loss in adjusted analysis. Among subgroups, the lowest SE quartile was associated with graft loss in white but not in black children. Thus, we found a complex relationship between SE position and graft loss in pediatric HT recipients. The finding of increased risk in the highest SE quartile children during the first year requires further confirmation. Black children and low SE position white children are at increased risk of graft loss after the first year.

Clinical use of sildenafil in pulmonary artery hypertension

Severe pulmonary hypertension is a debilitating disease with short life expectancy that often affects young people. It is usually idiopathic pulmonary artery hypertension and is characterized by progressive elevation of pulmonary artery pressure and vascular resistance, right ventricular failure and death with a limited median survival time. There is an imbalance in vasoconstrictive and vasodilatory substances. The phosphodiesterase-5 inhibitor sildenafil, a pulmonary and penile vasodilator initially approved for erectile dysfunction, is found to be efficacious in severe pulmonary artery hypertension. There are limited treatment options for the management of pulmonary artery hypertension in developing countries and sildenafil is a reasonable treatment option. This article reviews the relevant clinical data in pulmonary hypertension and the role of sildenafil in its management.

Racial and ethnic differences in mortality in children awaiting heart transplant in the United States

Racial differences in outcomes are well known in children after heart transplant (HT) but not in children awaiting HT. We assessed racial and ethnic differences in wait-list mortality in children <18 years old listed for primary HT in the United States during 1999-2006 using multivariable Cox models. Of 3299 listed children, 58% were listed as white, 20% as black, 16% as Hispanic, 3% as Asian and 3% were defined as 'Other'. Mortality on the wait-list was 14%, 19%, 21%, 17% and 27% for white, black, Hispanic, Asian and Other children, respectively. Black (hazard ratio [HR] 1.6, 95% confidence interval [CI] 1.3, 1.9), Hispanic (HR 1.5, CI 1.2, 1.9), Asian (HR, 2.0, CI 1.3, 3.3) and Other children (HR 2.3, CI 1.5, 3.4) were all at higher risk of wait-list death compared to white children after controlling for age, listing status, cardiac diagnosis, hemodyamic support, renal function and blood group. After adjusting additionally for medical insurance and area household income, the risk remained higher for all minorities. We conclude that minority children listed for HT have significantly higher wait-list mortality compared to white children. Socioeconomic variables appear to explain a small fraction of this increased risk.

Proteomics-based approach for identification and purification of human phosphate binding apolipoprotein from amniotic fluid

Human amniotic fluid is of both maternal and fetal origin; it protects the fetus and provides the environment for growth and development of the fetus. We used a proteomics-based approach for targeting and purifying human phosphate binding protein, a member of the DING family of proteins from amniotic fluid, using Blue Sepharose CL-6B, DEAE-Sephacel and gel filtration chromatography. The protein had earlier been reported to be serendipitously purified along with PON1 (paraoxonase 1). It was identified using electro-spray-ionization-time-of-flight mass spectrometry and was found to be human phosphate binding protein. Human phosphate binding proteins have been reported to play a role as phosphate scavengers and may have a protective function against phosphate-related disorders, such as atherosclerosis, diabetes and kidney stones.

Isolation, purification, crystallization and preliminary crystallographic studies of amaryllin, a plant pathogenesis-related protein from Amaryllis belladonna

A novel antifungal protein, amaryllin, has been isolated from the underground bulbs of Amaryllis belladonna, purified to homogeneity and crystallized. The protein was extracted using ammonium sulfate fractionation. The purified protein samples indicated a molecular weight of 15 kDa on SDS-PAGE. The protein showed antifungal activity against Aspergillus flavus and Fusarium oxysporum. The N-terminal sequence of the first 15 amino-acid residues was determined using Edman degradation and did not show significant sequence identity to any known protein. The protein was crystallized using the hanging-drop vapour-diffusion method with 30% PEG 8000 as precipitating agent. The crystals diffracted to 2.7 A resolution and belonged to the orthorhombic space group I222 or I2(1)2(1)2(1), with unit-cell parameters a = 48.6, b = 61.9, c = 79.6 A. The complete sequence and structure determination of amaryllin are in progress.

Prolactin inducible protein in cancer, fertility and immunoregulation: structure, function and its clinical implications

Prolactin inducible protein (PIP) is a 17- kDa single polypeptide chain, known by various names due to its versatile nature and function in human reproductive and immunological systems. It is expressed in several exocrine tissues such as the lacrimal, salivary, and sweat glands. Its expression is up regulated by prolactin and androgens, and estrogens down regulate it. Due to its over-expression in metastatic breast and prostate cancer, presently PIP is considered as a prognostic biomarker. Moreover, its aspartyl-proteinase nature suggests its role in tumor progression. PIP has unique features because it is small in size and plays multiple important functions. Its ability to bind potentially with CD4-T cell receptor, immunoglobulin G (IgG), actin, zinc alpha2-glycoprotein (ZAG), fibronectin and enamel pellicle, reveals its important biological functions. This is the first comprehensive review on the structure and functional analysis of PIP and its clinical applications.

Waiting list mortality among children listed for heart transplantation in the United States

BACKGROUND

Children listed for heart transplantation face the highest waiting list mortality in solid-organ transplantation medicine. We examined waiting list mortality since the pediatric heart allocation system was revised in 1999 to determine whether the revised allocation system is prioritizing patients optimally and to identify specific high-risk populations that may benefit from emerging pediatric cardiac assist devices.

METHODS AND RESULTS

We conducted a multicenter cohort study using the US Scientific Registry of Transplant Recipients. All children <18 years of age who were listed for a heart transplant between 1999 and 2006 were included. Among 3098 children, the median age was 2 years (interquartile range 0.3 to 12 years), and median weight was 12.3 kg (interquartile range 5 to 38 kg); 1294 (42%) were nonwhite; and 1874 (60%) were listed as status 1A (of whom 30% were ventilated and 18% were on extracorporeal membrane oxygenation). Overall, 533 (17%) died, 1943 (63%) received transplants, and 252 (8%) recovered; 370 (12%) remained listed. Multivariate predictors of waiting list mortality include extracorporeal membrane oxygenation support (hazard ratio [HR] 3.1, 95% confidence interval [CI] 2.4 to 3.9), ventilator support (HR 1.9, 95% CI 1.6 to 2.4), listing status 1A (HR 2.2, 95% CI 1.7 to 2.7), congenital heart disease (HR 2.2, 95% CI 1.8 to 2.6), dialysis support (HR 1.9, 95% CI 1.2 to 3.0), and nonwhite race/ethnicity (HR 1.7, 95% CI 1.4 to 2.0).

CONCLUSIONS

US waiting list mortality for pediatric heart transplantation remains unacceptably high in the current era. Specific high-risk subgroups can be identified that may benefit from emerging pediatric cardiac assist technologies. The current pediatric heart-allocation system captures medical urgency poorly. Further research is needed to define the optimal organ-allocation system for pediatric heart transplantation.

Characterization of anisotropy in viscoelastic properties of intra-abdominal soft tissues

A portable instrumentation rig is presented for characterizing nonlinear viscoelastic anisotropic response of intra-abdominal organ-tissues. Two linearly independent in-situ experiments are performed at each indentation site on the intra-abdominal organ, by subjecting the organ to 1) normal and 2) tangential displacement stimuli using the above robotic device. For normal indentation experiments, the indenter is ramped into the tissue and held for 10 seconds before sinusoidal indentation stimuli are applied. For tangential (shear) loading, the indenter tip is rigidly glued to the soft tissue surface. Sinusoidal displacement stimuli are then applied laterally in the tangential plane and the force response is recorded. Tangential loading is repeated along orthogonal directions to measure in-plane mechanical properties. Combined analysis of both experiments leads to assessment of anisotropy. In situ experiments on fresh human cadavers are currently under way at the Albany Medical College.

Cosmic inhomogeneities and averaged cosmological dynamics

If general relativity (GR) describes the expansion of the Universe, the observed cosmic acceleration implies the existence of a "dark energy." However, while the Universe is on average homogeneous on large scales, it is inhomogeneous on smaller scales. While GR governs the dynamics of the inhomogeneous Universe, the averaged homogeneous Universe obeys modified Einstein equations. Can such modifications alone explain the acceleration? For a simple generic model with realistic initial conditions, we show the answer to be "no." Averaging effects negligibly influence the cosmological dynamics.

Crystal structure of the novel complex formed between zinc alpha2-glycoprotein (ZAG) and prolactin-inducible protein (PIP) from human seminal plasma

This is the first report on the formation of a complex between zinc alpha2-glycoprotein (ZAG) and prolactin-inducible protein (PIP). The complex was purified from human seminal plasma and crystallized using 20% polyethylene glycol 9000 and 5% hexaethylene glycol. The structure of the complex has been determined using X-ray crystallographic method and refined to an R(cryst) of 0.199 (R(free)=0.239). The structure of ZAG is broadly similar to the structure of serum ZAG. The scaffolding of PIP consists of seven beta-strands that are organized in the form of two antiparallel beta-pleated sheets, resulting in the formation of a sandwiched beta-sheet. The amino acid sequence of PIP contains one potential N-glycosylation site at Asn77, and the same is found glycosylated with four sugar residues. The structure of the complex shows that the beta-structure of PIP is ideally aligned with the beta-structure of domain alpha3 of ZAG to form a long interface between two proteins. The proximal beta-strands at the long interface are arranged in an antiparallel manner. There are 12 hydrogen bonds and three salt bridges between ZAG and PIP. At the two ends of vertical interface, two salt bridges are formed between pairs of Lys41-Asp233 and Lys68-Glu229. On the perpendicular interface involving alpha1-alpha2 domains of ZAG and a loop of PIP, another salt bridge is formed. The internal space at the corner of the L-shaped structure is filled with solvent molecules including a carbonate ion. The overall buried area in the complex is approximately 914 A(2), which is considerably higher than the 660 A(2) reported for the class I major histocompatibility complex structures.

Crystal structure of the complex of group I PLA2with a group II-specific peptide Leu-Ala-Ile-Tyr-Ser (LAIYS) at 2.6 Å resolution

Phospholipases A(2)s (PLA(2)s) are widely distributed in mammals and snake venoms. They catalyze the production of arachidonic acid from membrane phospholipids leading to the bioynthesis of pro-inflammatory eicosanoids. A peptide Leu-Ala-Ile-Tyr-Ser (LAIYS) was designed and synthesized as a specific inhibitor of PLA(2). It was shown earlier that the peptide bound to group II PLA(2) specifically and had a dissociation constant (K(d)) of 8.8 x 10(-9) M. In the present studies for the binding of LAIYS with a group I PLA(2) from Naja naja sagittifera using surface plasmon resonance the dissociation constant was found to be 4.5 x 10(-5) M which is considerably lower than the value found for the group II PLA(2). In order to determine the details of binding at the molecular level, a group I PLA(2) from the venom of Naja naja sagittifera was crystallized with peptide LAIYS. The crystal structure showed the presence of LAIYS at the substrate-binding site but has fewer interactions than those observed with group II PLA(2) from Daboia russelli pulchella. The observed difference in the binding affinity is caused primarily due to poor fitting of the peptide LAIYS in the binding site of group I PLA(2). Apparently, the location of Trp 19 in group I PLA(2) is not favourable for the binding of LAIYS. The two complexes also differ drastically in the formation of intermolecular interactions. In the present structure, the side chain of Ser (P) interacts with His 48 and Asp 49 while in the complex with group II PLA(2) it was Tyr (P) OH that formed the corresponding interactions. Tyr (P) in group I PLA(2) is the main contributor of the hydrophobic interactions whereas in the complex of LAIYS with group II PLA(2) it was the peptide segment Leu-Ala-Ile that produced the bulk of hydrophobic forces. The structures further showed that the peptide LAIYS was fully inside the substrate-binding region of the group II PLA(2) while a significant portion of the peptide LAIYS was hanging outside the surface of the group I PLA(2). The buried area in the complex with group II PLA(2) was 811 A(2) whereas, the corresponding area in group I PLA(2) was 449 A(2). This shows that the peptide LAIYS is very compatible with the substrate-binding site of group II PLA(2) and rather poorly fits into the substrate-binding site of group I PLA(2). This indicates that a highly specific ligand for one form of PLA(2) may be a poor partner for another form of enzyme.

Endothelin and its receptor interactions: role of extracellular receptor domain and length of peptide ligands

Human endothelin B receptor and its domain-truncated forms were cloned and expressed in Pichia pastoris. Ligand binding studies with expressed proteins were carried out using biotinylated endothelins. Competitive binding and liposome incorporation studies showed that the extracellular region is essential for ligand binding and that longer peptides have higher affinity.

The mistletoe lectin I--phloretamide structure reveals a new function of plant lectins

The X-ray structure at 2.7A resolution of the complex between the European mistletoe lectin I (Viscum album, ML-I) and the plant growth hormone, 3-(p-hydroxyphenyl)-propionic acid amide (phloretamide, PA) from xylem sap has revealed the binding of PA at the so far undescribed hydrophobic cavity located between the two subunits of this ribosome-inhibiting protein. No such cavity is observed in related lectins. The binding of PA is achieved through interactions with the non-conserved residues Val228A, Leu230A, Arg388B, and the C-terminal Pro510B. It is conceivable that binding of PA to ML-I is part of a defence mechanism of the parasite against the host, whereby the parasite prevents the growth hormone of the host from interfering with its own regulatory system. The specific binding of PA to ML-I indicates that heterodimeric RIPs are multifunctional proteins whose functions in the cell have not yet been fully recognized and analyzed.

Cardiac rehabilitation improves heart rate recovery following peak exercise in children with repaired congenital heart disease

We assessed heart rate (HR) recovery following peak exercise before and after a 12-week cardiac rehabilitation program in 14 children, 12.1+/-1.8 years of age, with repaired complex congenital heart disease (CHD; 11 with Fontan surgery) and impaired exercise performance. Exercise testing using bicycle ergometry was performed at baseline, after completion of the rehab program and 1.0+/-0.2 years after the baseline test. These data were compared to HR recovery in 15 controls (age, 12.7+/-2.4 years) with CHD (13 with Fontan surgery) with two serial exercise tests at an interval of 1.1+/- 0.3 years. There was no change in peak HR between the two serial tests in either group. Peak VO2 improved in the rehab group (26.3+/-9.6 ml/kg/min at baseline vs 30.9+/-9.6 ml/kg/min after rehab, p=0.01) but remained unchanged in controls on serial testing. One-minute HR recovery (in beats per minute) improved significantly following completion of the rehab program (27+/-15 at baseline vs 40+/-23 after rehab, p=0.01). Partial improvement in 1-minute HR recovery in the rehab group persisted 1 year later (1-minute HR recovery, 35+/-19; p=0.1 compared to baseline). There was no change in 1-minute HR recovery over time in the control group (37+/-16 vs 40+/-13, p = not significant). In conclusion, HR recovery following peak exercise improves in children with CHD after participation in a cardiac rehab program.

Protective role of antioxidant enzymes under high temperature stress

An experiment was conducted to study the effect of high temperature stress on the antioxidant enzyme activity in five wheat genotypes viz., PBW 343, PBW 175, HDR-77, HD 2815 and HD 2865. There was significant increase in the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) in the late and very late planting and at all stages of plant growth, i.e., vegetative, anthesis and 15 days after anthesis (DAA), however glutathione reductase (GR) and peroxidase (POX) activity decreased under late and very late plantings compared to normal planting. In general HD 2815, HDR-77 showed relatively higher SOD, APX, GR, CAT and POX activity in the late plantings compared to PBW 343, PBW 175 and HD 2865. Significant reduction in chlorophyll content and increase in membrane injury index were observed in all genotypes with age, and also under late and very late sowings at all the stages of plant growth. However HD 2815 and HDR-77, which showed highest activity of various antioxidant enzymes under late and very late sowing also showed minimum reduction in chlorophyll content and lower membrane injury index, indicating the amelioration of high temperature stress induced oxidative stress by antioxidant enzymes. Various antioxidant enzymes showed positive correlation (r) with chlorophyll content and negative with membrane injury index at most of the stages in the five wheat genotypes.

Specific binding of non-steroidal anti-inflammatory drugs (NSAIDs) to phospholipase A2: structure of the complex formed between phospholipase A2 and diclofenac at 2.7 A resolution

Type IIA secretory phospholipase A2 (PLA2) enzymes catalyze the hydrolysis of the sn-2 ester bond of glycerophospholipids to release fatty acids and lysophospholipids. In order to elucidate the role of PLA2 in inflammatory disorders and to determine the mode of binding of non-steroidal anti-inflammatory drugs (NSAIDs) to PLA2, the detailed three-dimensional structure of a complex formed between a group IIA PLA2 from Daboia russelli pulchella and 2-[(2,6-dichlorophenyl)amino]benzeneacetic acid (diclofenac) has been determined. The preformed complex was crystallized by equilibrating the protein solution against a mixture of 0.20 M ammonium sulfate and 30% PEG 4000. The crystals belong to space group P4(3), with unit-cell parameters a = b = 53.0, c = 48.4 A. The structure was solved by the molecular-replacement method and refined to R(cryst) and R(free) factors of 0.192 and 0.211, respectively, using reflections to 2.7 A resolution. The structure showed that diclofenac occupies a very favourable position in the centre of the substrate-binding hydrophobic channel that allows a number of intermolecular interactions. The binding mode of diclofenac involved crucial interactions with important residues for substrate recognition such as Asp49, His48 and Gly30. In addition, it included three new interactions involving its Cl atoms with Phe5, Ala18 and Tyr22. It also showed an extensive network of hydrophobic interactions involving almost all of the residues of the substrate-binding hydrophobic channel. The binding affinity of diclofenac was determined using surface plasmon resonance, which gave an equilibrium constant of 4.8 +/- 0.2 x 10(-8) M.

Crystal structure of a calcium-induced dimer of two isoforms of cobra phospholipase A2 at 1.6 A resolution

The calcium-induced formation of a complex between two isoforms of cobra venom phospholipase A2 reveals a novel interplay between the monomer-dimer and activity-inactivity transitions. The monodispersed isoforms lack activity in the absence of calcium ions while both molecules gain activity in the presence of calcium ions. At concentrations higher than 10 mg/ml, in the presence of calcium ions, they dimerize and lose activity again. The present study reports the crystal structure of a calcium-induced dimer between two isoforms of cobra phospholipase A2. In the complex, one molecule contains a calcium ion in the calcium binding loop while the second molecule does not possess an intramolecular calcium ion. However, there are two calcium ions per dimer in the structure. The second calcium ion is present at an intermolecular site and that is presumably responsible for the dimerization. The calcium binding loops of the two molecules adopt strikingly different conformations. The so-called calcium binding loop in the calcium-containing molecule adopts a normal conformation as generally observed in other calcium containing phospholipase A(2) enzymes while the conformation of the corresponding loop in the calcium free monomer deviates considerably with the formation of a unique intraloop Gly33 (N)-Cys27 (O) = 2.74 A backbone hydrogen bond. The interactions of Arg31 (B) with Asp49 (A) and absence of calcium ion are responsible for the loss of catalytic activity in molecule A while interactions of Arg2 (B) with Tyr52 (B) inactivate molecule B.