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.

Improved neuropsychological and neurological functioning across three antiretroviral regimens in diverse resource-limited settings: AIDS Clinical Trials Group study a5199, the International Neurological Study

BACKGROUND

AIDS Clinical Trials Group (ACTG) A5199 compared the neurological and neuropsychological (NP) effects of 3 antiretroviral regimens in participants infected with human immunodeficiency virus type 1 (HIV-1) in resource-limited settings.

METHODS

Participants from Brazil, India, Malawi, Peru, South Africa, Thailand, and Zimbabwe were randomized to 3 antiretroviral treatment arms: A (lamivudine-zidovudine plus efavirenz, n = 289), B (atazanavir, emtricitabine, and didanosine-EC, n = 293), and C (emtricitabine-tenofovir-disoproxil fumarate plus efavirenz, n = 278) as part of the ACTG PEARLS study (A5175). Standardized neurological and neuropsychological (NP) screening examinations (grooved pegboard, timed gait, semantic verbal fluency, and finger tapping) were administered every 24 weeks from February 2006 to May 2010. Associations with neurological and neuropsychological function were estimated from linear and logistic regression models using generalized estimating equations.

RESULTS

The median weeks on study was 168 (Q1 = 96, Q3 = 192) for the 860 participants. NP test scores improved (P < .05) with the exception of semantic verbal fluency. No differences in neurological and neuropsychological functioning between treatment regimens were detected (P > .10). Significant country effects were noted on all NP tests and neurological outcomes (P < .01).

CONCLUSIONS

The study detected no significant differences in neuropsychological and neurological outcomes between randomized ART regimens. Significant improvement occurred in neurocognitive and neurological functioning over time after initiation of ARTs. The etiology of these improvements is likely multifactorial, reflecting reduced central nervous system HIV infection, better general health, and practice effects. This study suggests that treatment with either of the World Health Organization -recommended first-line antiretroviral regimens in resource-limited settings will improve neuropsychological functioning and reduce neurological dysfunction.

CLINICAL TRIALS REGISTRATION

NCT00096824.

Biomaterial implants mediate autologous stem cell recruitment in mice

Autologous stem cells, recognized as the best cells for stem cell therapy, are associated with difficult extraction procedures which often lead to more traumas for the patients and time-consuming laboratory work, which delays their subsequent application. To combat such challenges, it was recently uncovered that, shortly after biomaterial implantation, following the recruitment of inflammatory cells, substantial numbers of mesenchymal stem cells (MSC) and hematopoietic stem cells (HSC) were recruited to the implantation sites. These multipotent MSC could be differentiated into various lineages in vitro. Inflammatory signals may be responsible for the gathering of stem cells, since there is a good relationship between biomaterial-mediated inflammatory responses and stem cell accumulation in vivo. In addition, the treatment with the anti-inflammatory drug dexamethasone substantially reduced the recruitment of both MSC and HSC. The results from this work support that such strategies could be further developed towards localized recruitment and differentiation of progenitor cells. This may permit the future development of autologous stem cell therapies without the need for tedious cell isolation, culture and transplantation.