An expression signature of the angiogenic response in gastrointestinal neuroendocrine tumours: correlation with tumour phenotype and survival outcomes

Background:

Gastroenteropancreatic neuroendocrine tumours (GEP-NETs) are heterogeneous with respect to biological behaviour and prognosis. As angiogenesis is a renowned pathogenic hallmark as well as a therapeutic target, we aimed to investigate the prognostic and clinico-pathological role of tissue markers of hypoxia and angiogenesis in GEP-NETs.

Methods:

Tissue microarray (TMA) blocks were constructed with 86 tumours diagnosed from 1988 to 2010. Tissue microarray sections were immunostained for hypoxia inducible factor 1α (Hif-1α), vascular endothelial growth factor-A (VEGF-A), carbonic anhydrase IX (Ca-IX) and somatostatin receptors (SSTR) 1–5, Ki-67 and CD31. Biomarker expression was correlated with clinico-pathological variables and tested for survival prediction using Kaplan–Meier and Cox regression methods.

Results:

Eighty-six consecutive cases were included: 51% male, median age 51 (range 16–82), 68% presenting with a pancreatic primary, 95% well differentiated, 51% metastatic. Higher grading (P=0.03), advanced stage (P<0.001), high Hif-1α and low SSTR-2 expression (P=0.03) predicted for shorter overall survival (OS) on univariate analyses. Stage, SSTR-2 and Hif-1α expression were confirmed as multivariate predictors of OS. Median OS for patients with SSTR-2+/Hif-1α-tumours was not reached after median follow up of 8.8 years, whereas SSTR-2-/Hif-1α+ GEP-NETs had a median survival of only 4.2 years (P=0.006).

Conclusion:

We have identified a coherent expression signature by immunohistochemistry that can be used for patient stratification and to optimise treatment decisions in GEP-NETs independently from stage and grading. Tumours with preserved SSTR-2 and low Hif-1α expression have an indolent phenotype and may be offered less aggressive management and less stringent follow up.

Relationship of resting brain hyperconnectivity and schizophrenia-like symptoms produced by the NMDA receptor antagonist ketamine in humans

N-methyl-D-aspartate glutamate receptor (NMDA-R) antagonists produce schizophrenia-like positive and negative symptoms in healthy human subjects. Preclinical research suggests that NMDA-R antagonists interfere with the function of gamma-aminobutyric acid (GABA) neurons and alter the brain oscillations. These changes have been hypothesized to contribute to psychosis. In this investigation, we evaluated the hypothesis that the NMDA-R antagonist ketamine produces alterations in cortical functional connectivity during rest that are related to symptoms. We administered ketamine to a primary sample of 22 subjects and to an additional, partially overlapping, sample of 12 subjects. Symptoms before and after the experimental session were rated with the Positive and Negative Syndrome Scale (PANSS). In the primary sample, functional connectivity was measured via functional magnetic resonance imaging almost immediately after infusion began. In the additional sample, this assessment was repeated after 45 min of continuous ketamine infusion. Global, enhanced functional connectivity was observed at both timepoints, and this hyperconnectivity was related to symptoms in a region-specific manner. This study supports the hypothesis that pathological increases in resting brain functional connectivity contribute to the emergence of positive and negative symptoms associated with schizophrenia.

Spectrum of lymphoproliferative disorders following renal transplantation in North India

Post-transplant lymphoproliferative disorder (PTLD) is a well-recognized, but uncommon complication of organ transplantation. This study was a retrospective analysis of 2000 patients who underwent renal transplantation over a period of 30 years (1980-2010). Forty malignancies were diagnosed in 36 patients. Of these, 29 patients (1.45%) had PTLD (7 females, 22 males) accounting for 72.5% of all malignancies after transplantation. Twenty-two (75.8%) developed non-Hodgkin lymphoma and seven patients (24.2%) had myeloma. Diagnosis was made by biopsy of the involved organ in 21 patients (72.4%) and aspiration cytology in five patients (17.2%). In three patients, the diagnosis was made only at autopsy. Mean age at the time of diagnosis of PTLD was 41.9 years (range 21-69 years). Time interval from transplantation to the diagnosis of PTLD ranged from 3 months to 144 months with a median of 48 months. Only five patients (17.2%) developed PTLD within a year of transplantation. Twelve patients developed PTLD 1-5 years and 12 patients 5-10 years after transplantation. Organ involvement was extra nodal in 18 patients (82%). Thirteen (59%) patients had disseminated disease and nine (41%) had localized involvement of a single organ (brain-3, liver-1, allograft-1, perigraft node-1, retroperitoneal lymph nodes-3). Infiltration of the graft was noted in two patients. Patients with myeloma presented with backache, pathological fracture, unexplained anemia or graft dysfunction. PTLD was of B cell origin in 20 cases (70%). CD 20 staining was performed in 10 recent cases, of which 8 stained positive. Of the 26 patients diagnosed during life, 20 (69%) died within 1 year of diagnosis despite therapy. In conclusion, PTLD is encountered late after renal transplantation in the majority of our patients and is associated with a dismal outcome. The late onset in the majority of patients suggests that it is unlikely to be Epstein Barr virus related.

The biochemical utility of chromogranin A, chromogranin B and cocaine- and amphetamine-regulated transcript for neuroendocrine neoplasia

Neuroendocrine neoplasia (NEN) is a heterogeneous group of tumours and often represents a therapeutic challenge to clinicians. The peptides chromogranin A (CgA), chromogranin B (CgB) and cocaine- and amphetamine-regulated transcript (CART) are widely distributed throughout the neuroendocrine system. CgA and CgB have been used as general NEN biomarkers for many years, while CART has only recently been identified. Of these biomarkers, CgA is the most commonly used. However, circulating CgA concentrations exhibit considerable intra-individual biological variation, are altered by proton pump inhibitors (PPIs) and somatostatin analogues and are elevated in non-NEN malignancies. Therefore, interpretation of CgA results must be in the context of these confounding factors. The effects of treatment and non-NEN conditions on circulating CgB and CART concentrations are less well understood. CgB is less affected by impaired renal function and PPIs than CgA; while, circulating CART concentrations lack a diurnal variation in humans and are more reliable markers of pancreatic NEN malignancy than CgA. The utility of circulating CgA measurements in NEN prognosis, surveillance and disease recurrence has been widely investigated. However, the utility of CgB and CART in NEN management is yet to be elucidated. Further studies are needed to establish whether CgB and CART are useful alternatives to CgA.

An unusual cause of gross hematuria and renal dysfunction in a young male

Monoclonal immunoglobulin deposition disease (MIDD) is an uncommon disease with a peak incidence between the 5^th and 6^th decades of life. It is characterized by non-fibrillar, Congo red negative deposition of monoclonal immunoglobulins in various organs, including in the kidneys. MIDD can be of three types depending on the composition of the deposits, and includes light chain deposition disease (LCDD), heavy chain deposition disease and light and heavy chain deposition disease, of which LCDD is the most common. Renal involvement is a universal finding in MIDD, and is in the form of renal insufficiency, microscopic hematuria and nephrotic range proteinuria. Gross hematuria is a rare occurrence. Renal biopsy usually shows nodular sclerosing glomerulopathy on light microscopy and diffuse linear staining of glomerular and tubular basement membrane on immunofluorescence microscopy. We report a young male who presented with rapidly progressive renal failure and gross hematuria and was diagnosed as LCDD with nodular glomerulopathy and crescents on renal biopsy.

Lipoprotein metabolism differs between Marek's disease susceptible and resistant chickens

Marek's disease (MD) is a lymphoproliferative disease of chickens caused by MD virus and has an important impact on the poultry industry worldwide. There have been reports showing different physiological characteristics between MD susceptible and resistant chickens. However, little is known about whether there are differences in lipid metabolism between MD susceptible and resistant lines of chickens. In this study, we examined the BW and the weight of tissues (abdominal fat, breast muscle with bone, leg muscle with bone, liver, and heart), the lipoprotein-cholesterol concentrations and distributions, and the plasma and tissue levels of adiponectin and its receptors in the highly resistant and susceptible lines during chicken growth. Our data showed that the increase in total cholesterol during growth was mainly due to the elevation of cholesterol in the low-density/very low-density lipoprotein fraction in MD susceptible chickens, whereas the increase of total cholesterol was mainly attributable to the increase in high-density lipoprotein-cholesterol in MD resistant chickens. Meanwhile, the MD resistant line appeared to have increased plasma adiponectin levels compared with MD susceptible chickens during growth. Taken together, our data suggested that lipoprotein-cholesterol and adiponectin metabolism are different between MD susceptible and resistant chickens.

Association between -1486 T>C and +1174 G>A single nucleotide polymorphisms in TLR9 gene and severity of lupus nephritis

Signaling through Toll-like receptor-9 (TLR9), a mediator of innate immune responses, could have a role in the pathogenesis of systemic lupus erythematosus (SLE). Some studies have shown an association between polymorphisms in the TLR9 gene and disease manifestations. We investigated whether two single nucleotide polymorphisms (-1486 T>C and +1174 G>A) in the TLR9 gene are associated with the risk of renal involvement in SLE. DNA samples from 112 SLE patients (62 with lupus nephritis) and 100 healthy controls were obtained. TLR9 polymorphisms (-1486 T>C and +1174 G>A) were analyzed by polymerase chain reaction–restriction fragment length polymorphism. Genotype and allelic frequencies were compared between lupus patients and healthy controls. Clinical and laboratory manifestations and activity scores on renal biopsy of patients with lupus nephritis were compared between various genotypes. There was no difference in the frequency of genotype or allele distribution at either of the two loci between lupus patients and controls and in lupus patients with or without nephritis. Patients with CC/CT genotype at the -1486 position had higher serum creatinine (P = 0.03) and Austin activity scores (P = 0.015). Patients with AA/AG genotype at +1174 position showed higher serum creatinine (P = 0.04), proteinuria (P = 0.011), anti-dsDNA titers (P < 0.001) and Austin activity scores (P = 0.003) than the GG genotype. Variations at the -1486 and +1174 positions of TLR9 gene are not associated with increased risk of SLE or that of kidney involvement in North Indians. CC/CT genotypes at -1486 and AA/AG at +1174 positions are associated with more severe kidney disease at presentation.

Optimization for rapid synthesis of silver nanoparticles and its effect on phytopathogenic fungi

In this present study, silver nanoparticles were synthesized by green chemistry approach using Acalypha indica leaf extract as reducing agents. The reaction medium employed in the synthesis process was optimized to attain better yield, controlled size and stability. Further, the biosynthesized silver nanoparticles were conformed through UV-vis spectrum, XRD and HR-TEM analyses. Different concentration of silver nanoparticles were tested to know the inhibitory effect of fungal plant pathogens namely Alternaria alternata, Sclerotinia sclerotiorum, Macrophomina phaseolina, Rhizoctonia solani, Botrytis cinerea and Curvularia lunata. Interestingly, 15 mg concentration of silver nanoparticles showed excellent inhibitory activity against all the tested pathogens. Thus, the obtained results clearly suggest that silver nanoparticles may have important applications in controlling various plant diseases caused by fungi.

A comparison of the performance of ⁶⁸Ga-DOTATATE PET/CT and ¹²³I-MIBG SPECT in the diagnosis and follow-up of phaeochromocytoma and paraganglioma

PURPOSE

To compare the sensitivity of (123)I-metaiodobenzylguanidine (MIBG) SPECT and (68)Ga-DOTATATE PET/CT in detecting phaeochromocytomas (PCC) and paragangliomas (PGL) in the initial diagnosis and follow-up of patients with PCC and PGL disease.

METHODS

Retrospective analysis of 15 patients with PCC/PGL who had contemporaneous (123)I-MIBG and (68)Ga-DOTATATE imaging.

RESULTS

Of the 15 patients in the series, 8 were concordant with both modalities picking up clinically significant lesions. There were no patients in whom both modalities failed to pick up clinically significant lesions. There was discordance in seven patients: 5 had positive (68)Ga-DOTATATE and negative (123)I-MIBG, and 2 (12 and 14) had negative (68)Ga-DOTATATE and positive (123)I-MIBG. Utilizing (123)I-MIBG as the gold standard, (68)Ga-DOTATATE had a sensitivity of 80 % and a positive predictive value of 62 %. The greatest discordance was in head and neck lesions, with the lesions in 4 patients being picked up by (68)Ga-DOTATATE and missed by (123)I-MIBG. On a per-lesion analysis, cross-sectional (CT and MRI) and (68)Ga-DOTATATE was superior to (123)I-MIBG in detecting lesions in all anatomical locations, and particularly bony lesions.

CONCLUSION

First, (68)Ga-DOTATATE should be considered as a first-line investigation in patients at high risk of PGL and metastatic disease, such as in the screening of carriers for mutations associated with familial PGL syndromes. Second, if (123)I-MIBG does not detect lesions in patients with a high pretest probability of PCC or PGL, (68)Ga-DOTATATE should be considered as the next investigation. Third, (68)Ga-DOTATATE hould be considered in preference to (123)I-MIBG in patients in whom metastatic spread, particularly to the bone, is suspected.

Rituximab induced pulmonary fibrosis in a patient with lupus nephritis

We describe a 26-year-old woman who was diagnosed eleven years ago with systemic lupus erythematosus and who had suffered multiple relapses. She presented with class IV lupus nephritis with thrombotic microangiopathy, for which she received three doses of rituximab along with plasmapheresis, with no response, and soon became dialysis dependent. One month after the last dose of rituximab, she presented with dyspnoea and hypoxia. A transbronchial lung biopsy revealed pulmonary fibrosis. A diagnosis of rituximab induced pulmonary fibrosis was made after excluding other causes and she was treated with intravenous methyl prednisolone with which there was marked improvement in symptoms and hypoxemia. This is the first report of rituximab induced pulmonary fibrosis in a patient with lupus nephritis.

Capilia test for identification of Mycobacterium tuberculosis in MGIT™-positive cultures

BACKGROUND

The performance of the Capilia test for rapid identification of Mycobacterium tuberculosis complex (MTC) in Mycobacterium Growth Indicator Tube (MGIT) positive samples with contaminating organisms is not well documented.

OBJECTIVE

To assess the diagnostic yield of the Capilia test in the rapid identification of MTC in MGIT-positive cultures.

DESIGN

A total of 459 selected sputum samples were cultured using BACTEC™ MGIT™ 960. Tubes flagged positive by the MGIT instrument (MGIT-positive) were examined for acid-fast bacilli and cording in smears, spotted on blood agar (BA), subcultured for biochemical tests and tested using the Capilia test. Based on smear and growth on BA, MGIT-positive tubes were grouped into MGIT true-positive, MGIT-positive with contamination and MGIT contamination. Performance parameters of Capilia test such as sensitivity, specificity, efficiency, and positive and negative predictive values (PPV, NPV) for each of these groups were determined against biochemical tests as gold standard.

RESULTS

Of the 346 MGIT-positives, respectively 233, 73 and 40 were MGIT true-positive, MGIT-positive with contamination and MGIT contamination. For the three groups, the PPV and NPV of the Capilia test were respectively 97%, 96% and 100%, and 32%, 27% and 60%.

CONCLUSION

In settings with high contamination of MGIT cultures, the performance of the Capilia test is diminished.

Cloning and characterization of chicken fat mass and obesity associated (Fto) gene: fasting affects Fto expression

Fat mass and obesity associated gene (Fto), also known as Fatso, is a member of the Fe-II and 2-oxoglutarate-dependent dioxygenase superfamily. Recent studies in humans and rodents suggest that Fto is involved in food intake regulation and lipid metabolism, whereas single nucleotide mutations in the Fto gene are associated with obesity and type 2 diabetes. The Fto gene is highly conserved from green algae to humans, but little is known about the avian Fto gene or protein. The objectives of the current study were to clone full-length chicken Fto cDNA and to determine the effect of age or feeding status on Fto expression. With the use of rapid amplification of cDNA ends, the full-length chicken Fto cDNA was cloned and found to share 63% to 66% homology with the mammalian Fto nucleotide sequence. Several regions of the chicken Fto protein, including the substrate (2-oxoglutarate) binding domains, were found to be identical to mammalian Fto protein. Western blotting with anti-human Fto antibody and reverse transcription PCR studies showed that Fto protein and gene were ubiquitously expressed in various tissues of the chicken. With the use of quantitative PCR, Fto mRNA levels were found to be higher in liver and skeletal muscle of 8-wk-old chickens than in 4-wk-old chickens. In addition, alterations in feeding status resulted in significant changes in Fto mRNA and Fto protein expression in the liver but not in skeletal muscle and adipose tissue of broiler chickens. Taken together, our data suggest that Fto probably plays a significant role in liver function and energy metabolism in the chicken.

K(ATP) channel openers in the trigeminovascular system

BACKGROUND

The ATP-sensitive K(+) (K(ATP)) channel openers levcromakalim and pinacidil are vasodilators that induce headache in healthy people. The neuropeptide calcitonin gene-related peptide (CGRP) induces headache in healthy people and migraine in migraineurs, potentially through a mechanism that involves opening of vascular or neuronal K(ATP) channels and mast cell degranulation. Using rat as a model, we studied the molecular presence of K(ATP) channels in the trigeminovascular system. Furthermore, we examined whether K(ATP) channel openers stimulate the in vitro release of CGRP and whether they degranulate dural mast cells.

METHODS

mRNA and protein expression of K(ATP) channel subunits were studied in the trigeminal ganglion (TG) and trigeminal nucleus caudalis (TNC) by qPCR and western blotting. In vitro CGRP release was studied after application of levcromakalim (1 µM) and diazoxide (10 µM) to freshly isolated rat dura mater, TG and TNC. Rat dural mast cells were challenged in situ with levcromakalim (10(-5) M) to study its potential degranulation effect.

RESULTS

mRNA and protein of K(ATP) channel subunits Kir6.1, Kir6.2, SUR1 and SUR2B were identified in the TG and TNC. K(ATP) channel openers did not release or inhibit capsaicin-induced CGRP release from dura mater, TG or TNC. They did also not induce dural mast cell degranulation.

CONCLUSIONS

K(ATP) channel openers do not interact with CGRP release or mast cell degranulation. Activation of these channels in the CNS is antinociceptive and therefore cannot explain the headache induced by K(ATP) channel openers. Thus, they are likely to induce headache by interaction with extracerebral K(ATP) channels, probably the SUR2B isoforms.

The ethics of clinical and epidemiological research

The global burden of tuberculosis (TB) demands that research be undertaken. The vulnerability of the populations most at risk for TB demands that such research be subject to ethical review to protect their rights and interests. In this brief article we cannot review the vast and important literature bearing on the ethics of clinical and epidemiological research and public health surveillance. Instead, we have focused on three questions that have been at the center of discussion and debate and which have special relevance for TB. First, we examine a question that has special bearing when wealthy nations or international organizations carry out research in poor countries: what does justice require in the post trial period? Second, we examine the question of how the principles of consent and confidentiality may require modification in record-based epidemiological research. Third, we look at the challenges posed by public health surveillance, which in many cases requires case reporting by clinicians to public health agencies. By way of conclusion, we take note of the centrality of enhancing the institutional capacities for ethical review of research in poor nations.