Reconstruction of Complex Abdominal Wall Defects

Introduction

Reconstruction of large abdominal wall defects not amenable to primary closure remains a challenging problem. These defects result from trauma, previous surgery, infection and tumour resection. The primary objectives of abdominal wall reconstructions are to protect abdominal contents and provide functional support. The abdominal wall reconstruction aims at providing basic component parts, i.e. skin, soft tissue and fascia. For large soft tissue defects, pedicled or free flap closure can be used. In clean wounds, fascial replacement is accomplished with synthetic mesh provided there is adequate soft tissue coverage.

Methods

We treated a total of 20 consecutive patients with complex abdominal wall defects utilizing various reconstructive procedures. There were 15 males (75%) and 5 females (25%). The aetiology included dehiscence of laparotomy wounds in eight (40%), following ablative surgery for malignant tumours in seven (35%), trauma in three (15%) and congenital defects in two (10%) cases. The reconstructive procedures consisted of onlay prolene mesh in seven (35%), Gore-Tex (PTFE) dual mesh both as inlay and onlay in five (25%), facial partition release technique in three (15%), inlay prolene mesh covered with omentum and split skin graft in two (10%), inlay prolene mesh covered with expanded skin in two (10%), and Gore-Tex dual mesh covered with latissimus dorsi myocutaneous flap in one (5%) case. Postoperatively none developed mesh infection or extrusion. Three patients with malignant aetiology received postoperative radiotherapy. During follow up, one patient developed ventral hernia cephalad to the repair and one died due to recurrence of abdominal wall malignancy.

Conclusion

The reconstruction of an abdominal wall defect requires a comprehensive plan of preoperative and post operative care of the patient and aims toward restoration of abdominal structural integrity by a variety of procedures. The use of new biomaterials and tissue expanders provides reliable and durable abdominal wall closure along with good aesthetic results.Key Words: Abdominal wall defect, Mesh repair, Abdominal wall reconstruction     

The Role of anti-HBc IgM in Screening of Blood Donors

Background

Transfusion transmitted hepatitis B has always been a dreaded disease, with incidence of increased transmission through donated blood. The screening test for hepatitis B infection is detection of HBsAg that does not rule out the risk of transmission of hepatitis B as the donor may be in the ‘window period’. During this period, detection of the antibody to the hepatitis B core antigen (anti-HBc) IgM type serves as a useful serological marker. The aim of this study was to screen blood donors for anti-HBc type IgM and anti - HBc Ag total for detection and to find their incidence amongst blood donors.

Methods

2552 voluntary blood donors were screened by the ELISA method for HBsAg and anti - HBc IgM and other mandatory screening markers. 704 of the test blood samples were also screened for anti-HBc total.

Result

Of the 2552 donor, 47 (1.84 %) cases were HBsAg positive. A total of 11 (0.43 %) blood units were reactive for HBcAg IgM and of these, 10 (0.39 %) were HBsAg negative and reactive for anti-HBcAg IgM. Of the 704 samples tested for anti - HBcAg total, 112 (15.9%) samples were reactive.

Conclusion

Screening of blood for anti-HBc total is practical in the western world as the incidence of HBsAg and anti-HBc is low in these countries and these positive blood units for anti - HBcAg total can be discarded. This may not be practical in India as the incidence of anti- HBcAg total is high in our population. It is recommended that all blood units should be tested for anti - HBc IgM for infectivity status of the blood donors in the window period and to discard blood if positive.Key Words: Window period, Hepatitis B surface antigen, Anti hepatitis B core antigen     

Non-toxic Pseudomonas aeruginosa exotoxin A expressing the FMDV VP1 G-H loop for mucosal vaccination of swine against foot and mouth disease virus

Synthetic peptides derived from the G-H loop of the foot and mouth disease virus (FMDV) capsid protein VP1 are relatively poor at recapitulating the native conformation present in the virus, and thus are often poor immunogens. We hypothesized that a candidate mucosal vaccine against FMDV could be developed using the non-toxic Pseudomonas aeruginosa exotoxin A (ntPE) to deliver the G-H loop in its native conformation. An added benefit of this approach is the potential for ntPE to serve as an effective carrier/adjuvant molecule for delivery of the fusion protein across the epithelial barrier by virtue of its capacity to bind to CD91. A chimeric protein (ntPE-GH) was generated by inserting the coding sequence of the G-H loop into an expression plasmid encoding ntPE, in place of the native Ib loop. Recombinant ntPE-GH and wild-type ntPE were each expressed in Escherichia coli, purified over a nickel resin, then administered intranasally to the pigs, with or without the mucosal adjuvant cholera toxin (CT). Both the ntPE and ntPE-GH induced mucosal and systemic immune responses against ntPE; moreover, ntPE-GH administered without CT induced anti-GH loop serum IgG antibodies. In conclusion, these data demonstrate that ntPE can be used as a mucosal carrier/adjuvant to induce an immune response against the VP1 G-H loop of FMDV.     

BRCA1 alterations are associated with endometriosis,but BRCA2 alterations show no detectable endometriosis risk: a study in Indian population

Purpose

To investigate the role of genetic variations and expression alterations of BRCA1 and BRCA2 genes in the pathophysiology of endometriosis.

Methods

A genetic association study was conducted in 573 endometriosis cases and 490 controls of Indian origin. We genotyped 13 selected promoter SNPs of BRCA1 gene and 2 selected promoter SNPs of BRCA2 gene by PCR-sequencing analysis. In addition, to better understand genetic contributions to the pathophysiology of endometriosis, the expression pattern of BRCA1 & 2 was analyzed in the eutopic endometria of endometriosis cases and controls by western-blot and immunohistochemical analysis.

Results

Our results revealed significant association between BRCA1 rs71361504 (−/GTT) SNP and endometriosis risk in Indian women (P < 0.0001), while the remaining SNPs of both BRCA1 & 2 genes showed no difference between cases and controls. Western-blot and immunohistochemical analysis revealed significantly decreased BRCA1 expression levels in eutopic endometria of patients compared with controls (P < 0.05). Furthermore, nuclear BRCA1 was frequently lost compared with cytoplasmic BRCA1 in eutopic endometria of patients. Expression of BRCA2 did not differ between patients and controls.

Conclusions

BRCA1 rs71361504 SNP may modify the endometriosis risk in Indian women. In addition, decreased expression of BRCA1 may play an important role in the pathophysiology of endometriosis. The analysis of BRCA1 genetic variants and/or expression might help to identify patients at high risk for disease outcome.

Electronic supplementary material

The online version of this article (doi:10.1007/s10815-014-0379-9) contains supplementary material, which is available to authorized users.     

Pharmacodynamic profile of the direct thrombin antagonist bivalirudin given in combination with the glycoprotein IIb/IIIa antagonist eptifibatide

Background Because of the adverse characteristics associated with heparin, direct antagonists of thrombin have been investigated as anticoagulants during percutaneous coronary interventions. However, the hematologic and clinical interactions between direct thrombin antagonists and inhibitors of platelet glycoprotein IIb-IIIa are incompletely explored. Methods Forty-two patients who underwent elective percutaneous coronary intervention were randomized to receive a bivalirudin 1.0 mg/kg bolus followed by a 4-hour infusion at 2.5 mg/kg/h; a bivalirudin 0.75 mg/kg bolus followed by a 4-hour infusion at 1.75 mg/kg; or a heparin 60 U/kg bolus. All the patients also received eptifibatide, given as 2 sequential boluses of 180 μg/kg followed by a 2 μg/kg/min infusion for 18 to 24 hours, and aspirin. Results After the bolus dose of the study drug, turbidimetric platelet aggregation in response to 5 μmol/L adenosine diphosphate increased in patients assigned to heparin but not those assigned to bivalirudin. After eptifibatide, platelet aggregation was eliminated in all 3 treatment groups. The effect of heparin and the effects of both bivalirudin regimens on the formation of thrombin antithrombin complexes and prothrombin fragment 1.2 were comparable. Neither agent affected the formation of platelet-monocyte complexes or expression of CD 63 lysosomal antigen. There were no major bleeding events, and a single non-Q-wave myocardial infarction (MI) occurred in a patient treated with bivalirudin. Conclusion These findings show the feasibility of combining the direct thrombin antagonist bivalirudin with a potent antagonist of platelet glycoprotein IIb-IIIa. Clinical trials are needed to assess the safety and efficacy of this combination. (Am Heart J 2002;143:585-93.)     

An integrated WRF/HYSPLIT modeling approach for the assessment of PM2.5 source regions over the Mississippi Gulf Coast region

Fine particulate matter (PM_2.5) is majorly formed by precursor gases, such as sulfur dioxide (SO₂) and nitrogen oxides (NO_x), which are emitted largely from intense industrial operations and transportation activities. PM_2.5 has been shown to affect respiratory health in humans. Evaluation of source regions and assessment of emission source contributions in the Gulf Coast region of the USA will be useful for the development of PM_2.5 regulatory and mitigation strategies. In the present study, the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model driven by the Weather Research & Forecasting (WRF) model is used to identify the emission source locations and transportation trends. Meteorological observations as well as PM_2.5 sulfate and nitric acid concentrations were collected at two sites during the Mississippi Coastal Atmospheric Dispersion Study, a summer 2009 field experiment along the Mississippi Gulf Coast. Meteorological fields during the campaign were simulated using WRF with three nested domains of 36, 12, and 4?km horizontal resolutions and 43 vertical levels and validated with North American Mesoscale Analysis. The HYSPLIT model was integrated with meteorological fields derived from the WRF model to identify the source locations using backward trajectory analysis. The backward trajectories for a 24-h period were plotted at 1-h intervals starting from two observation locations to identify probable sources. The back trajectories distinctly indicated the sources to be in the direction between south and west, thus to have origin from local Mississippi, neighboring Louisiana state, and Gulf of Mexico. Out of the eight power plants located within the radius of 300?km of the two monitoring sites examined as sources, only Watson, Cajun, and Morrow power plants fall in the path of the derived back trajectories. Forward dispersions patterns computed using HYSPLIT were plotted from each of these source locations using the hourly mean emission concentrations as computed from past annual emission strength data to assess extent of their contribution. An assessment of the relative contributions from the eight sources reveal that only Cajun and Morrow power plants contribute to the observations at the Wiggins Airport to a certain extent while none of the eight power plants contribute to the observations at Harrison Central High School. As these observations represent a moderate event with daily average values of 5?C8???g?m^?3 for sulfate and 1?C3???g?m^?3 for HNO₃ with differences between the two spatially varied sites, the local sources may also be significant contributors for the observed values of PM_2.5.     

The management of ultrasound equipment at Sheffield Teaching Hospitals NHS Foundation Trust

Management of ultrasound equipment at Sheffield Teaching Hospitals NHS Foundation Trust is described. The organisation and input of various stakeholders and their involvement with ultrasound equipment management and scientific ultrasound is discussed. Two important stakeholders are the Medical Equipment Management Group and the Radiation Safety Steering Committee. The Medical Equipment Management Group has a specific sub-group, the Ultrasound sub-group, and its role is to coordinate the purchase, replacement and quality assurance of ultrasound equipment in the Trust. The Radiation Safety Steering Committee has a non-ionising radiation representative and the role of this committee is to provide corporate assurance that any health and safety issues arising from the use of radiation to either patients, members of the public or staff within the Trust are being effectively managed. The Ultrasound sub-group of the Medical Equipment Management Group has successfully brought together management of all ultrasound equipment within the Trust and is in the process of fulfilling the quality assurance and training milestones set out by the Medical Equipment Management Group. Advice from the Radiation Safety Steering Committee has helped to increase awareness of ultrasound safety and good scanning practice, especially in the case of neonatal ultrasound imaging, within the Trust. In addition, the RSSC has given advice on clinical pathways for patients undergoing ionising radiation imaging while being treated by extra-corporeal shockwave lithotripsy.     

TaqIA polymorphism in dopamine D2 receptor gene complicates weight maintenance in younger obese patients

ObjectiveThe A1 allele of the TaqIA polymorphism in the dopamine D2 receptor gene (rs1800497) has been associated with obesity. However, the effect of the polymorphism on the success in weight loss and/or weight maintenance during weight-loss programs has not been evaluated thus far.MethodsThe rs1800497 was genotyped in 202 (135 female, 67 male) severely obese individuals with an initial body mass index of 41.7 ± 0.5 kg/m² who participated in a weight-loss program consisting of a weight-loss phase with a formula diet (12 wk) and a weight-maintenance phase (40 wk). Measurements were collected at baseline, after the weight-loss phase, and at the end of the weight-maintenance phase at 1 y.ResultsGenotyping revealed 4 A1A1, 67 A1A2, and 131 A2A2 genotype carriers. Of the 202 subjects in the program, 66.8% completed the program and 33.2% terminated prematurely. Neither the attrition rate (P = 0.44) nor the overall weight loss was influenced by the different genotypes (P = 0.96). However, younger A1⁺ participants (A1A1 and A1A2) had a higher body mass index at all time points (baseline, P = 0.04; after weight loss, P = 0.05; after weight maintenance, P = 0.02). They also showed less overall weight loss (P = 0.05), which derived mainly from a greater weight regain during the maintenance phase (P = 0.02).ConclusionIn this program, younger A1⁺ participants exhibited problems in maintaining weight loss during a weight-loss program.     

Effect of surfaces on fluid-phase prekallikrein activation

The activation of prekallikrein by factor XII fragments (XIIf), during incubation in plastic tubes was previously noted to be increased by high molecular weight (HMW) kininogen as well as other plasma proteins. In this report, we investigated the mechanism responsible for this increase. Although we confirmed that HMW kininogen, bovine serum albumin, fibrinogen, cold insoluble globulin, and mixed phospholipids apparently increased prekallikrein activation, we found that the product of prekallikrein activation (kallikrein) lost substantial activity in less than 0.5 min after exposure to a variety of fresh surfaces. This loss was partially prevented by the presence of various proteins and phospholipids. Similar protection against inactivation of XIIf, the enzyme in this reaction, was also found. In contrast, no loss of the substrate, prekallikrein, was observed during incubation. The loss of kallikrein activity was found to be proportional to the surface area of the incubation vessel as well as the concentration of kallikrein. Further loss of kallikrein activity could also be prevented by pretreating the vessel with kallikrein. We therefore conclude that various substances apparently affect prekallikrein activation in a purified system by preventing the enzyme and product in the reaction mixture from losing activity due to adsorption to a surface.