A London experience 1995-2012: demographic, dietary and biochemical characteristics of a large adult cohort of patients with renal stone disease

BACKGROUND

Kidney stone disease has an estimated prevalence of around 10%. Genetic as well as environmental factors are thought to play an important role in the pathogenesis of renal stones.

AIM

The aim of our study was to analyse and report the main characteristics of patients with kidney stones attending a large UK metabolic stone clinic in London between 1995 and 2012.

DESIGN

A cross-sectional study.

METHODS

Analysis of data from stone formers attending the University College and Royal Free Hospitals' metabolic stone clinic from 1995 to 2012. Demographic, clinical, dietary and biochemical characteristics have been summarized and analysed for men and women separately; trends over time have also been analysed.

RESULTS

Of the 2861 patients included in the analysis, 2016 (70%) were men with an average age of 47 years (range 18-87 years) and median duration of disease of 6 years (range 0-60 years). The prevalence of low urine volume, hypercalciuria, hyperoxaluria, hyperuricosuria and hypocitraturia was 5.6%, 38%, 7.9%, 18% and 23%, respectively. The prevalence of several risk factors for stones increased over time. The majority of stones were mixed, with around 90% composed of calcium salts in varying proportion.

CONCLUSION

Our findings in a large cohort of patients attending a London-based stone clinic over the past 20 years show differences in distributions of risk factors for stones for men and women, as well as metabolic profiles and stone composition. The impact of most risk factors for stones appeared to change over time.

Systemic jasmonic acid modulation in mycorrhizal tomato plants and its role in induced resistance against Alternaria alternata

Tomato plants colonised with the arbuscular mycorrhizal (AM) fungus Glomus fasciculatum show systemic induced resistance to the foliar pathogen Alternaria alternata, as observed in interactions of other AM-colonised plants with a range of pathogens. The role of jasmonic (JA) and salicylic (SA) acid in expression of this mycorrhiza-induced resistance (MIR) against A. alternata was studied by measuring: (i) activity of enzymes reported to be involved in their biosynthesis, namely lipoxygenase (LOX) and phenylammonia lyase (PAL); and (ii) levels of methyl jasmonate (MeJA) and SA. Transcript abundance of some defence genes associated with JA and SA response pathways were also studied. Both LOX and PAL activity increased twofold in response to pathogen application to control plants. AM-colonised plants had three-fold higher LOX activity compared to control plants, but unlike controls, this did not increase further in response to pathogen application. Higher LOX activity in AM-colonised plants correlated with four-fold higher MeJA in leaves of AM-colonised plants compared to controls. Treatment of plants with the JA biosynthesis inhibitor salicylhydroxamic acid (SHAM) led to 50% lower MeJA in both control and AM-colonised plants and correlated with increased susceptibility to A. alternata, suggesting a causal role for JA in expression of MIR against the pathogen. Genes involved in JA biosynthesis (OPR3) and response (COI1) showed six- and 42-fold higher expression, respectively, in leaves of AM-colonised plants compared to controls. AM-colonised plants also showed increased expression of the SA response gene PR1 and that of the wound-inducible polypeptide prosystemin. Our results suggest that the systemic increase in JA in response to AM colonisation plays a key role in expression of MIR against A. alternata.

Selective activation of angiotensin AT2 receptors attenuates progression of pulmonary hypertension and inhibits cardiopulmonary fibrosis

BACKGROUND AND PURPOSE

Pulmonary hypertension (PH) is a devastating disease characterized by increased pulmonary arterial pressure, which progressively leads to right-heart failure and death. A dys-regulated renin angiotensin system (RAS) has been implicated in the development and progression of PH. However, the role of the angiotensin AT2 receptor in PH has not been fully elucidated. We have taken advantage of a recently identified non-peptide AT2 receptor agonist, Compound 21 (C21), to investigate its effects on the well-established monocrotaline (MCT) rat model of PH.

EXPERIMENTAL APPROACH

A single s.c. injection of MCT (50 mg·kg(-1) ) was used to induce PH in 8-week-old male Sprague Dawley rats. After 2 weeks of MCT administration, a subset of animals began receiving either 0.03 mg·kg(-1) C21, 3 mg·kg(-1) PD-123319 or 0.5 mg·kg(-1) A779 for an additional 2 weeks, after which right ventricular haemodynamic parameters were measured and tissues were collected for gene expression and histological analyses.

KEY RESULTS

Initiation of C21 treatment significantly attenuated much of the pathophysiology associated with MCT-induced PH. Most notably, C21 reversed pulmonary fibrosis and prevented right ventricular fibrosis. These beneficial effects were associated with improvement in right heart function, decreased pulmonary vessel wall thickness, reduced pro-inflammatory cytokines and favourable modulation of the lung RAS. Conversely, co-administration of the AT2 receptor antagonist, PD-123319, or the Mas antagonist, A779, abolished the protective actions of C21.

CONCLUSIONS AND IMPLICATIONS

Taken together, our results suggest that the AT2 receptor agonist, C21, may hold promise for patients with PH.

Mutations seen among patients with pheochromocytoma and paraganglioma at a referral center from India

Determining the mutational status of susceptibility genes including RET, VHL, SDHx (SDHB, SDHC, SDHD) among patients with pheochromocytoma/paraganglioma (PCC/PGL) is gaining importance. These genes have not been systematically characterized among patients with PCC/PGL from India. The aim of the work was to screen the most frequently mutated genes among patients with PCC/PGL to determine the frequency and spectrum of mutations seen in this region. Fifty patients with PCC/PGL treated at our tertiary care hospital between January 2010 and June 2012 were screened for mutations in susceptibility genes using an algorithmic approach. Thirty-two percent (16/50) of patients were found to be positive for mutations including mutations among RET (n=4), VHL (n=6), SDHB (n=3), and SDHD (n=3) genes. None of these patients were positive for SDHC mutations. A significant association was found between young patients with bilateral tumors and VHL mutations (p=0.002). Two of the 3 patients with extra-adrenal SDHB associated tumors, had unique mutations, viz., c.436delT (exon 5) and c.788_857del (exon 8), one of which was malignant. High frequency of mutations seen among patients in this study emphasizes the need to consider mutational analysis among Indian patients with PCC/PGL.

Hematopoietic PBX-interacting protein (HPIP) is over expressed in breast infiltrative ductal carcinoma and regulates cell adhesion and migration through modulation of focal adhesion dynamics

The scaffolding protein, hematopoietic PBX-interacting protein (HPIP/PBXIP1), regulates cell migration necessary for cancer cell dissemination. However, the mechanism that governs this process remains unknown. We show here that HPIP expression is associated with stages of breast cancer where cell dissemination results in poor patient outcome. Our investigation finds a novel association of HPIP with focal adhesion kinase (FAK) regulating FA dynamics. Interestingly, this interaction that led to activation of FAK protein was mediated by the C-terminal domain of HPIP and not the typical integrin-binding motif. Further, short hairpin RNA-mediated knockdown of FAK expression significantly reduced HPIP-induced cell migration indicating participation of FAK pathway. Live-cell time-lapse imaging and biochemical analysis further established the role of HPIP in microtubule-induced FA disassembly. We also found that HPIP-mediated MAPK activation led to phosphorylation and subsequent activation of calpain2, and the activated calpain2 in turn proteolyses FA protein, talin. Interestingly, HPIP is also proteolysed by calpain2 in breast cancer cells. The proteolysis of HPIP and talin by calpain2, and the activation of calapin2 by HPIP-mediated MAPK phosphorylation, is a novel regulatory axis to modulate the cell migration signal. Together, we have determined HPIP as a novel activator of FAK and a new substrate of calpain2. These molecular interactions between HPIP and FAK, and HPIP and calpain2 regulate cell adhesion and migration through modulation of FA dynamics.

High-resolution computed tomography of the pulmonary manifestations of connective tissue diseases

Pulmonary disease is common in patients with connective tissue disease (CTD) and confers significant morbidity and mortality. High-resolution computed tomography (HRCT) provides considerable information regarding the distribution and severity of thoracic disease in CTD. Different anatomical compartments of the lung can be simultaneously affected in a given individual. Furthermore, lung injury may not be solely related to the underlying CTD, but may be caused by treatment or infections. Finally, the risk of developing cancer is increased in patients with certain CTDs. In this review, the HRCT manifestations of CTD are initially discussed with respect to the different compartments involved, followed by a description of the spectrum of pulmonary disease commonly occurring in specific CTDs.

Systematic review and meta-analysis of cytokeratin 19-based one-step nucleic acid amplification versus histopathology for sentinel lymph node assessment in breast cancer

Background

One-step nucleic acid amplification (OSNA) is a new rapid assay for detecting breast cancer metastases during surgery, saving a second procedure for patients requiring an axillary clearance. Many centres in the UK and abroad have adopted OSNA in place of routine histopathology, despite no published meta-analysis. The aim of this systematic review and meta-analysis was to determine whether intraoperative OSNA for lymph node assessment is comparable to routine histopathology in the detection of clinically relevant metastases.

Methods

PubMed, Embase, Web of Knowledge and regional databases were searched for relevant studies published before December 2012. Included studies compared OSNA and standard histology using fresh lymph nodes that were assessed in a clearly defined systematic manner in accordance with the index study.

Results

Twelve eligible studies were identified that included 5057 lymph nodes from 2192 patients. Although meta-analysis using a random-effects model showed a similar overall proportion of macrometastases detected (429 of 3234 versus 432 of 3234; odds ratio 0·99, 95 per cent confidence interval 0·86 to 1·15), analysis of concordance showed that the pooled positive predictive value for detecting macrometastases was 0·79. This suggests that up to 21 per cent of patients found to have macrometastases using OSNA would have an axillary clearance when histology would have classified the deposits as non-macrometastases. Furthermore, analysis of data from the index publication showed that the range of cytokeratin 19 titres for tumours of a given volume is too wide to predict tumour size.

Conclusion

OSNA has an unacceptably low positive predictive value, leading to axillary clearances that would not be recommended if standard histology had been used to assess the sentinel node.

Gentamicin use in neonates: should we have a change of practice?

Background

Gentamicin, one of the most commonly used antibiotics in neonates, has potential toxicity. This study was performed to determine the incidence of potential toxicity of gentamicin in term and preterm neonates.

Methods

A one-year retrospective study in neonates admitted to Special Baby Care Units at University Hospital of North Durham and Darlington Memorial Hospitals. We reviewed each admission and looked through the case notes in detail to document information about gentamicin administration, dosage and elevated gentamicin levels in the blood. Pre-third dose gentamicin levels >2 mg/L were classified as elevated.

Results

Overall, 192 babies (83 term and 109 preterm) had documented gentamicin levels. Of these, 43% (84/192) manifested elevated gentamicin levels. Of the babies with elevated gentamicin levels, 67% (56/84) weighed less than 2.5 kg. When a combination of gestation period and weight was considered, 61% (51/84) of preterm infants weighing <2.5 kg had elevated levels whereas only one term infant <2.5 kg exhibited elevated levels.

Conclusion

Preterm neonates and specifically low birth weight neonates tolerate gentamicin poorly. Dosage and/or interval of administration of the medication may need modification in this group to minimise toxicity.

Comparison of the flexural strength of two dual cure adhesive resin cements under oral simulated conditions: an in-vitro study

The purpose of this in vitro study was to evaluate the flexural strength of the newly developed self-adhesive dual cure resin cement and compare it with conventional resin cement under oral simulated conditions. A conventional resin cement (Calibra) and self adhesive resin cement (RelyX U100) were selected and 40 specimens of each cement were fabricated for the study. Half of these specimens were polymerized directly whereas the other half were polymerized through 2 mm of porcelain disc. Specimens were tested after 24hrs and after 30 days immersion in artificial saliva. A three point bending test was performed using universal testing machine at a crosshead speed of 1mm/min. Overall RelyX U100 showed higher mean flexural strength compared to Calibra (141.55 MPa, 119.46MPa, respectively). When the specimens of both the cements were light cured through 2 mm porcelain disc, their flexural strength decreased significantly. The mean flexural strength of both self adhesive and conventional dual cure adhesive resin cements was increased significantly after storage in artificial saliva for 30 days at 37 degreeC. Among the two dual cure resin cements, the self adhesive dual cure cement (RelyX U100) showed increased overall mean flexural strength as compared to conventional resin cement (Calibra) under all the curing and storage protocols.

Evaluation and comparison of the internal fit and marginal accuracy of base metal (nickelchromium) and zirconia copings before and after ceramic veneering: a sem study

This study compares the internal fit and marginal adaptation of copy milled Zirconia copings with Nickel-Chromium (Ni-Cr) copings fabricated using a lost wax technique before and after ceramic veneering. A standardized metal master die simulating a prepared crown was fabricated and twenty impressions of the metal die were made and poured with die stone. Wax patterns were made on ten dies and cast while light cure resin patterns were made on the other ten dies for copy milling the Zirconia copings. Five specimens from each group were subjected to ceramic veneering. All the test specimens were luted on to the fresh dies, embedded in dental plaster, sectioned and image analysis done using scanning electron microscopy. Thereafter statistical analysis is done using student t-test. The linear measurements for internal fit and marginal discrepancy were increased for Zirconia compared with Ni-Cr copings. The difference in the values of all the specimens of all the groups were not statistically significant (P > 0.05) except the values comparing the internal fit of Zirconia and Ni-Cr copings before ceramic veneering (P < 0.001) which was statistically significant. The internal fit and marginal adaptability of Ni-Cr copings were found to be better than the Copy milled Zirconia copings but internal fit and marginal adaptability deteriorated after ceramic veneering.