Single-center kidney paired donation: the Methodist San Antonio experience

Many potential kidney transplant recipients are unable to receive a live donor transplant due to crossmatch or blood type incompatibility. Kidney paired donation increases access to live donor transplantation but has been significantly underutilized. We established a kidney paired donation program including consented incompatible donor/recipient pairs as well as compatible pairs with older non-human leukocyte antigen identical donors. Over a 3-year period, a total of 134 paired donor transplants were performed, including 117 incompatible pairs and 17 compatible pairs. All transplants were done with negative flow cytometry crossmatches and five were done with desensitization combined with paired donation. Kidney paired donation transplants included two-way and three-way exchanges as well as three chains initiated by nondirected donors. Of the sensitized recipients transplanted by paired donation, 44% had calculated panel reactive antibody levels greater than 80%. Transplantation of females and prior transplant recipients was significantly higher with paired donation. Only three episodes of rejection occurred and no transplants were lost due to rejection. These data highlight the potential of kidney paired donation and suggest that all transplant centers should be actively engaged in paired donation to increase access to live donor transplantation.

MicroRNA-155 inhibits proliferation and migration of human extravillous trophoblast derived HTR-8/SVneo cells via down-regulating cyclin D1

MiR-155 is known to participate in various cellular processes by targeting gene expression. We previously revealed a link between miR-155 and perturbation of trophoblast invasion and differentiation. This study aimed to investigate the target molecule(s) of miR-155 on the influence on the proliferation and migration of trophoblast cells. Bioinformatics analysis showed that, at the 3' untranslated region (UTR) of cyclin D1, six bases are complementary to the seed region of miR-155. Luciferase assays and cyclin D1 3'UTR transfection assays validated that cyclin D1 3'UTR was the target of miR-155 in HTR-8/SVneo cells. Overexpression of miR-155 in HTR-8/SVneo cells reduced the level of cyclin D1 protein, decreased cell proliferation and invasion, and increased cell number at the G1 stage. Furthermore, the increased expression of miR-155 also regulated the protein levels of kinase inhibitory protein p27 and phosphorylated cytoskeletal protein filamin A. In conclusion, we found that cyclin D1 may be a target of miR-155 in HTR-8/SVneo cells, and demonstrated a negative regulatory role of miR-155 involved in cyclin D1/p27 pathway in proliferation and migration of the cells.

A prospective study of bacterial flora in nasal cavity of patients with persistent allergic rhinitis

It remains unanswered whether persistent allergic inflammation in nasal mucosa alters bacterial colonization and infection. The aim of this study was to investigate the bacterial flora in the nasal cavity of patients with persistent allergic rhinitis (PAR) and to correlate the bacteriological findings with presence of nasal symptoms, nasal eosinophil and neutrophil counts. A total of 255 subjects, aged between 6 - 74 years (mean 33.9 years) was randomly selected from a population-based rhinitis survey study in Singapore. All subjects went through a thorough medical history and nasal examinations. Serum specific IgE to a panel of common house dust mites, nasal cytological and microbiological examinations were performed. PAR was diagnosed in 107 patients and none of them had received previous regular therapy. There is a significant relationship between PAR and eosinophil grades, but not with neutrophil count. No statistically significant difference was found in quantitative and qualitative bacterial flora in nasal cavity between PAR patients and subjects with non-rhinitis or with non-allergic rhinitis. There is a significant inverse correlation between ongoing rhinorrhoea and quantitative bacterial load, and between signs of nasal mucosa (pale and edema) and the presence and type of bacterial pathogens. In conclusion, our study demonstrates that patients with untreated (or using PRN medicine) PAR do not result in a significant change in bacterial flora in their nasal cavity.

Risk scoring system for prediction of contrast-induced nephropathy in patients with pre-existing renal impairment undergoing percutaneous coronary intervention

INTRODUCTION

Baseline renal impairment is the most recognised risk factor for development of contrast-induced nephropathy (CIN) post percutaneous coronary intervention (PCI). We examined the additional risk factors in this high-risk group and aimed to develop a risk model for prediction of CIN.

METHODS

A cohort of 770 consecutive patients with existing impaired renal function (estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2), who received routine prophylactic saline hydration and oral N-acetylcysteine treatment while undergoing PCI between May 2005 to October 2008 in our centre, were enrolled. The study endpoint, CIN, was defined as > 25% increase from baseline creatinine within 48 hours post PCI.

RESULTS

Despite routine prophylaxis, CIN occurred in 11.4% of the patients. Important clinical predictors for CIN were age (odds ratio [OR] 1.59, 95% confidence level [CI] 1.0-2.52, p = 0.049), anaemia with haemoglobin < 11 mg/dL (OR 2.26, 95% CI 1.41-3.61, p = 0.001), post-procedure creatinine kinase rise (OR 1.12, 95% CI 1.07-1.16 for every 500 u/L increase, p < 0.001), systolic hypotension with blood pressure < 100 mmHg (OR 2.53, 95% CI 1.16-5.52, p = 0.016) and higher contrast volume. The incidence of CIN was significantly higher in patients with more severe renal failure (6.3%, 17.4% and 40.8% when eGFR was 40-60, 20-40 and < 20 ml/min/1.73 m2 respectively, p < 0.001). A prediction model was developed based on these findings. The incidence of CIN could vary from 2% to > 50% depending on these additional risk profiles.

CONCLUSION

Patients with impaired renal function undergoing PCI are at high risk of developing CIN despite traditional prophylaxis. A model of risk prediction could be used to predict its occurrence.

A novel multi-parameter scoring system for distinguishing sarcoidosis from sputum negative tuberculosis

BACKGROUND

Sarcoidosis is a granulomatous disorder of unknown cause, affecting multiple organs. Tuberculosis is the world's second most common cause of death from infectious diseases. Due to the similar clinical, radiological and histopathological pictures in sarcoidosis and tuberculosis, Mycobacterium tuberculosis has been considered as potential infectious factor. However, it remains difficult to distinguish sarcoidosis from tuberculosis, especially when sputum examinations for mycobacterium are negative.

METHODS

1. to establish a scoring system for differentiating sarcoidosis and tuberculosis: We collected the risk factors, laboratory data and the data of clinical, radiographic, pathological manifestations from the 117 of sarcoidosis patients and 181 of sputum negative tuberculosis patient. And we put them into the designed form. Based on the results of univariate analysis, clinical experience and the literature, we further selected 13 variables that were more supportive to distinguish the two diseases. Finally 9 variables were selected based on logistic regression to establish the scoring systems with significant differences between the two diseases. The beta-coefficient form the logistic regression were used to calculate the weight of each variable. Four types of comprehensive scoring models were established in the end (clinical-- radiographic; clinical--radiographic--radionuclide; clinical--radiographic--pathological and clinico-radiographic--radionuclide--pathological group). Receiver operating characteristics (ROC) analysis was used to determine an optimal cutoff point for each scoring system. 2. to validate the accuracy of the established scoring system: 73 of new sarcoidosis patients and 57 of new tuberculosis patients were chosen to assess the diagnosis accuracy of the four scoring systems.

RESULTS

1. we established four types of comprehensive scoring models, included clinical--radiographic; clinical--radiographic--radionuclide; clinical--radiographic--pathological and clinico--radiographic--radionuclide--pathological scoring models, the optimal cutoff values respectively were 9, 17, 18 and 22, the sensitivity and specificity of the four scoring system to distinguish the two diseases respectively were: 93.16% (109/117) and 97.79% (177/181), 92.31% (108/117) and 98.90% (179/181); 93.16% (109/117) and 98.90% (179/181); 94.87% (111/117) and 98.90% (179/181). 2. Validation of the scoring systems with 130 new patients (73 of sarcoidosis and 57 of tuberculosis):, the sensitivity and specificity of CR, CRE, CRP, CREP were 91.78% (67/73) and 87.72% (50/57), 97.26% (69/73) and 98.25% (56/57), 94.52% (71/73) and 96.49% (55/57), 98.63% (72/73) and 98.25% (56/57) respectively.

CONCLUSIONS

The four scoring systems established by this study can be utilized to differentiate sarcoidosis and sputum negative tuberculosis effectively. Based on the availability of clinical-radiographical/histopathological data, any of the four diagnostic scoring systems were reliable tools for differential diagnosis, with increased information leading to better discrimination.

Overexpression of adiponectin promotes focal angiogenesis in the mouse brain following middle cerebral artery occlusion

Recent studies indicate that overexpression of adiponectin (APN) could attenuate ischemic brain injury. However, the mechanism of APN effect remains unclear. In this study, we investigated the cellular mechanisms of APN action during cerebral ischemia. Adult mice (n=120) received an intracerebral injection of adeno-associated viral vector carrying the APN gene (AAV-APN). The mice were subjected to a transient ispilateral middle cerebral artery occlusion (tMCAO) after 7-day AAV-APN gene transfer. Cortical atrophy volume, neurological function, microvessels counts, phospho-AMPK and downstream angiogenic factor vascular endothelial growth factor (VEGF) were examined. Overexpression of APN was observed in the mouse brain following AAV-APN gene transfer. Cortical atrophy volume was attenuated in the AAV-APN-transduced mice compared with the AAV-GFP and saline-treated mice (7.9 ± 0.6%, 19.8 ± 0.3% and 20.3 ± 1.1%, respectively, P<0.05), with significant improvement in neurological function and an increased number of microvessels (199 ± 5 vs 151 ± 4 and 148 ± 4 mm(-2), P<0.01). Furthermore, the expression of phospho-AMPK and VEGF were increased in the AAV-APN-transduced compared with the control mice (P<0.01), whereas inhibiting phospho-AMPK, reducing VEGF expression and attenuating the effect of APN on brain atrophy and angiogenesis (P<0.01). APN overexpression attenuates ischemia-induced brain atrophy and has improvement in neurological function. The consequence is related to promotion of focal angiogenesis. The AMPK signaling pathway has an important role in upregulating angiogenic factor VEGF.

Novel monoclonal antibodies to ESAT-6 and CFP-10 antigens for ELISA-based diagnosis of pleural tuberculosis

OBJECTIVE

To elucidate the potential of monoclonal antibodies (mAbs) of culture filtrate protein 10 (CFP-10) and early secretory antigenic target 6 (ESAT-6) in tuberculosis (TB) diagnosis.

DESIGN

We generated and characterised monoclonal and polyclonal antibodies against Mycobacterium tuberculosis-specific antigens ESAT-6 and CFP-10 by immunising BALB/c mice with an ESAT-6/CFP-10 fusion protein. Stable hybridoma cell lines were established and mAbs were specifically identified by immunoblotting and immunoprecipitation. The mouse mAbs were used to coat plates, and biotin-labelled polyclonal antibodies were used to detect the antigens. One hundred and seventy-three samples of sputum culture supernatants and pleural effusion aspirates have been tested.

RESULTS

The ESAT-6 enzyme-linked immunosorbent assay (ELISA) detected the culture supernatants and pleural effusion specimens that were positive for M. tuberculosis, but failed to identify M. tuberculosis-positive specimens in the non-M. tuberculosis culture supernatants or control specimens. This yielded a sensitivity of 95.4% and a specificity of 100% for the ESAT-6-specific ELISA. The CFP-10 ELISA presented less satisfactory sensitivity and specificity, of respectively 81.6% and 92.2%. Results showed positive detection rates of ESAT-6 and CFP-10 of 86.8% (33/38) and 76.3% (29/38) for the diagnosis of tuberculous pleural effusion in patients bacteriologically negative for M. tuberculosis culture.

CONCLUSION

The ESAT-6 and CFP-10 ELISAs incorporating mAbs generated in this study serve as potential tools in the laboratory diagnosis of TB.

Correlation of brain natriuretic peptide and microalbuminuria in patients with heart failure

OBJECTIVE

To evaluate the changes of plasma levels of N-terminal pro-brain natriuretic pepide (NT-proBNP) and microalbuminuria (MAU) in patients with heart failure and the correlation between them.

METHODS

Ninety-one patients with heart failure were divided into different groups according to different stages of heart failure. Plasma levels of NT-proBNP were measured by microsome enzyme immunoassay (MEIA). Plasma levels of MAU were determined by immune scattering turbidimetry (ICTM). Simultaneously, left ventricular ejection fraction (LVEF) and left ventricular end diastolic diameter (LVEDD) were measured by Doppler echocardiography for all patients. The correlation of NT-proBNP and MAU was evaluated at different stages of heart failure.

RESULTS

The plasma levels of NT-proBNP and MAU increased with the severity of heart failure. There was a high correlation between NT-proBNP and MAU (r = 0.885, p < 0.001).

CONCLUSION

Both NT-proBNP and MAU levels were closely associated with the severity of heart failure.

Interleukin-17 exacerbates hepatic steatosis and inflammation in non-alcoholic fatty liver disease

Mechanisms associated with the progression of simple steatosis to non-alcoholic fatty liver disease (NAFLD) remain undefined. Regulatory T cells (T(regs)) play a critical role in regulating inflammatory processes in non-alcoholic steatohepatitis (NASH) and because T helper type 17 (Th17) functionally oppose T(reg)-mediated responses, this study focused on characterizing the role of Th17 cells using a NAFLD mouse model. C57BL/6 mice were fed either a normal diet (ND) or high fat (HF) diet for 8 weeks. Mice in the HF group had a significantly higher frequency of liver Th17 cells compared to ND-fed mice. Neutralization of interleukin (IL)-17 in HF mice ameliorated lipopolysaccharide (LPS)-induced liver injury reflected by decreased serum alanine aminotransferase (ALT) levels and reduced inflammatory cell infiltrates in the liver. In vitro, HepG2 cells cultured in the presence of free fatty acids (FFA; oleic acid and palmitic acid) for 24 h and IL-17 developed steatosis via insulin-signalling pathway interference. IL-17 and FFAs synergized to induce IL-6 production by HepG2 cells and murine primary hepatocytes which, in combination with transforming growth factor (TGF-β), expanded Th17 cells. It is likely that a similar process occurs in NASH patients, as there were significant levels of IL-17(+) cell infiltrates in NASH patient livers. The hepatic expression of Th17 cell-related genes [retinoid-related orphan receptor gamma (ROR)γt, IL-17, IL-21 and IL-23] was also increased significantly in NASH patients compared to healthy controls. Th17 cells and IL-17 were associated with hepatic steatosis and proinflammatory response in NAFLD and facilitated the transition from simple steatosis to steatohepatitis. Strategies designed to alter the balance between Th17 cells and T(regs) should be explored as a means of preventing progression to NASH and advanced liver diseases in NAFLD patients.

Genome-wide association with MRI atrophy measures as a quantitative trait locus for Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with considerable evidence suggesting an initiation of disease in the entorhinal cortex and hippocampus and spreading thereafter to the rest of the brain. In this study, we combine genetics and imaging data obtained from the Alzheimer's Disease Neuroimaging Initiative and the AddNeuroMed study. To identify genetic susceptibility loci for AD, we conducted a genome-wide study of atrophy in regions associated with neurodegeneration in this condition. We identified one single-nucleotide polymorphism (SNP) with a disease-specific effect associated with entorhinal cortical volume in an intron of the ZNF292 gene (rs1925690; P-value=2.6 × 10(-8); corrected P-value for equivalent number of independent quantitative traits=7.7 × 10(-8)) and an intergenic SNP, flanking the ARPP-21 gene, with an overall effect on entorhinal cortical thickness (rs11129640; P-value=5.6 × 10(-8); corrected P-value=1.7 × 10(-7)). Gene-wide scoring also highlighted PICALM as the most significant gene associated with entorhinal cortical thickness (P-value=6.7 × 10(-6)).

Combinatorial treatment of bone marrow stem cells and stromal cell-derived factor 1 improves glycemia and insulin production in diabetic mice

Transdifferentiation of stem cells into insulin-producing cells for the treatment of diabetes have shown promising but inconsistent results. We examined the potential for attracting bone marrow stem cells (BMSCs) to the pancreas using a chemokine, stromal cell-derived factor 1 (SDF-1). SDF-1 treatment markedly increased the number of GFP labeled BMSCs in the pancreas, but surprisingly, the majority was observed in liver. The liver cells had typical pancreatic endocrine cell gene expression including insulin I, insulin II, PDX-1, somatostatin, and glucagon. Combined treatment with SDF-1 and BMSC transplant reduced hyperglycemia and prolonged the long-term survival of diabetic mice, and a sub group had complete normoglycemia (<150 mg/dl), restored blood insulin levels, and normal glucose tolerance. Our results suggest that SDF-1 could potentially be used to improve the homing of stem cells and β-cell regeneration. The mechanism appears to involve an increase in insulin producing cells mainly in the liver.

Densitometry trends in postmenopausal Asian women undergoing bisphosphonate treatment

INTRODUCTION

Bisphosphonates have been shown to be effective in reducing the risk of fragility fractures in several landmark clinical trials conducted in Western populations. However, limited studies on bone mineral densitometry (BMD) trends have been conducted in Asian women. We conducted a retrospective review of electronic records to determine the actual BMD trends in a local population of postmenopausal women on bisphosphonate treatment.

METHODS

The electronic records of all women over 50 years of age who had undergone BMD at Singapore General Hospital in 2004 were examined. Patients who were later started on bisphosphonates and continued the treatment for at least two years were selected for the study. Their subsequent BMD results were recorded, and longitudinal analysis was applied to determine the BMD trends as a cohort.

RESULTS

A total of 254 postmenopausal women were included for analysis. Their mean BMD T-score was -2.70 before treatment, and improved to -2.56 and -2.27 one and two years after treatment, respectively. However, the score deteriorated to -2.50 and -2.62 three and four years after treatment, respectively. The difference between each year's results and those of the baseline was statistically significant.

CONCLUSION

In our study, the BMD scores in our local population showed improvement in the first two years of bisphosphonate treatment but declined subsequently. Our findings contrasted with those of studies conducted in Western populations. Further prospective studies are suggested so as to elucidate the actual BMD trends and fracture risk reduction in Asian women on bisphosphonate treatment.

Development of a novel monoclonal antibody to B7-H4: characterization and biological activity

Objective

B7-H4, a member of the B7 family of immunoregulatory receptors, may participate in the negative regulation of cell-mediated immunity. Aberrant B7-H4 expression is detected in some tumors and it plays a role in the occurrence and development of tumors. The aim of this study was to elucidate the functional and structural properties of B7-H4.

Methods

We developed a monoclonal antibody (mAb) against the extracellular domain of B7-H4 through immunization of Balb/c mice with 3T3-mB7-H4 cells which expressed extrinsic B7-H4. A stable hybridoma cell line was established. Then, we analysised the characterization of the mAb through Enzyme linked immunosorbent assay (ELISA), Immunoprecipitation (IP), western blotting, Immunohistochemical (IHC), and tested the biological activity of the mAb.

Results

ELISA, IP, and western blotting analyses indicated that the mAb specifically recognized B7-H4. In addition, flow cytometry demonstrated that the mAb exhibits excellent reactivity when applied to leukemic cells. IHC staining revealed that the mAb stained in a predominantly diffuse plasmalemmal or cytoplasmic pattern when applied to certain tumor tissues. The preliminary results of the mAb's biological activity showed that the mAb could effectively inhibit the function of B7-H4 in the inhibition of T cell, while promotingg the growth of T cells and the secretion of Interleukin-2 (lL-2), Interleukin-4 (IL-4), Interleukin10 (IL-10) and Interferon-γ (IFN-γ).

Conclusion

This mAb will be a valuable tool for the further investigation of B7-H4 function.

A cohort study of risk factors and clinical outcome predictors for patients presenting with unstable angina and non ST segment elevation myorardial infraction undergoing coronary intervention

INTRODUCTION

Thrombolysis in Myocardial Infarction (TIMI) score has been used to predict outcomes in patients presenting with unstable angina (UA) and non-ST elevation myocardial infarction (NSTEMI). Our study assessed other clinical predictors for patients with UA/NSTEMI undergoing early percutaneous coronary intervention (PCI).

MATERIALS AND METHODS

A cohort of 3822 patients presented with UA/NSTEMI from June 2001 to March 2008 in our center were recruited. Patients underwent PCI during admission. We analyzed the potential risk predictors for major adverse cardiac events (MACE) and death at 1 month and 6 month.

RESULTS

Median age was 57.1 +/- 11.1, 78.1 percent men, 34.5 percent had diabetes, 58.8 percent had hypertension. Coronary lesions involving left main and proximal left anterior descending artery was 27.6 percent. 36.1 percent had NSTEMI. Significant predictors for mortality at 6 months were age older than 70 years (p = 0.001, OR = 5.5), female gender (p = 0.001, OR = 2.98), anaemia (p < 0.001 OR = 8.47), baseline renal impairment (P < 0.001, OR = 7.38) and development of contrast nephropathy (CIN) which was defined as 25% or 0.5 mg/dl increase from baseline Creatinine within 48 h after PCI (p = 0.005, OR = 5.8). Diabetes was a predictor of MACE at 6 months (p = 0.003, OR = 1.51) but not mortality.

CONCLUSIONS

In patients with UA/NSTEMI, our study showed that MACE and mortality were increased in elderly, female and presence of anaemia. Mortality, but not MACE was increased in chronic renal impairment and development of CIN; while diabetes increased only MACE, but not mortality.

SUMMARY

We analyzed a cohort of 3822 patients with UA/NSTEMI underwent PCI and found that elderly, female, presence of anemia, diabetes and chronic renal impairment were high risk predictors for adverse clinical outcome. In addition, development of CIN increased mortality.

Detection of Laribacter hongkongensis using species-specific duplex PCR assays targeting the 16S rRNA gene and the 16S-23S rRNA intergenic spacer region (ISR)

AIMS

For the rapid detection of Laribacter hongkongensis, which is associated with human community-acquired gastroenteritis and traveller's diarrhoea, we developed a duplex species-specific PCR assay.

METHODS AND RESULTS

Full-length of the 16S-23S rRNA intergenic spacer region (ISR) sequences of 52 L. hongkongensis isolates were obtained by PCR-based sequencing. Two species-specific primer pairs targeting 16S rRNA gene and ISR were designed for duplex PCR detection of L. hongkongensis. The L. hongkongensis species-specific duplex PCR assay showed 100% specificity, and the minimum detectable level was 2.1 × 10(-2) ng μl(-1) genomic DNA which corresponds to 5000 CFU ml(-1).

CONCLUSIONS

The high specificity and sensitivity of the assay make it suitable for rapid detection of L. hongkongensis.

SIGNIFICANCE AND IMPACT OF THE STUDY

This species-specific duplex PCR method provides a rapid, simple, and reliable alternative to conventional methods to identify L. hongkongensis and may have applications in both clinical and environmental microbiology.