Idiopathic bilateral optic atrophy in the rhesus macaque

PURPOSE: To document the existence of idiopathic bilateral optic atrophy (BOA) in rhesus macaque monkeys and to characterize the structural and functional consequences of this condition. METHODS: In vivo assessment of retinal and optic nerve structure included fundus biomicroscopy and stereophotography. Functional analyses included transient pattern-reversal electroretinography (PERG) and full-field flash ERG, with both white flashes while dark adapted and red flashes on a blue background used to assess the photopic negative response (PhNR). Also measured were visual evoked cortical potentials (VEPs) and multifocal (mf)ERGs, with both a standard fast and slowed (7F) stimulation sequence. Post mortem histologic evaluation was performed on a subset of five animals with BOA and compared with data from 22 healthy normal animals. Blood tests, including vitamin E, B(12), folate, lead, and complete blood cell count with differential were obtained on the four animals that remained alive. RESULTS: Animals with BOA showed temporal pallor of the optic nerve head and thinning of the retinal nerve fiber layer (RNFL) between the temporal vascular arcades (i.e., of the papillomacular bundle). Severity of optic atrophy and RNFL loss varied between animals from mild to severe, but was similar in the two eyes of each animal. Functional changes included greater loss of the PERG N95, compared with the P50 component and substantial reduction of mfERG high-frequency components. The mfERG low-frequency components were slightly larger than normal. None of the full-field flash ERG amplitudes (a-wave, b-wave, oscillatory potentials, or PhNR) was significantly different from normal. There were no consistent abnormalities found in the results of any blood test. Histologic findings included axonal loss and gliosis limited to the temporal optic nerve, reduction of nuclei within the retinal ganglion cell layer, and thinning of the temporal retinal RNFL. CONCLUSIONS: The existence of BOA in nonhuman primates warrants caution on the part of investigators who use these animals in experimental models of ophthalmic disease.     

Enhancement of plasmid DNA immunogenicity with linear polyethylenimine

The utility of plasmid DNA as an immunogen has been limited by its weak immunogenicity. In the present study, we evaluated the ability of a family of linear polyethylenimine (PEI) polymers, complexed to plasmid DNA, to augment DNA expression in vivo and to enhance antigen‐specific adaptive immune responses. We showed that four of five structurally different PEIs that we evaluated increased in vivo DNA expression 20‐ to 400‐fold, and enhanced DNA‐induced epitope‐specific CD8+ T‐cell responses 10‐ to 25‐fold in BALB/c and C57BL/6J mice respectively, when delivered intravenously. Functional studies of the PEI‐DNA‐induced CD8+ T‐cell responses demonstrated that formulation of DNA with PEI was associated with increased numbers of cells secreting type I cytokines. In addition, PEI‐DNA complexes improved antigen‐specific T_H1‐helper cell and humoral responses. Most importantly, the PEI‐DNA complexes elicited memory cellular responses, capable of rapid expansion and accelerated clearance of a lethal dose of recombinant Listeria monocytogenes. Lastly, we identified physical properties of PEI‐DNA complexes that are associated with enhanced DNA‐elicited immunogenicity. These findings demonstrate that PEI polymers can play an important role in the development of DNA‐based vaccines in the setting of infectious disease prevention and cancer therapy.     

Control of hyperglycaemia in paediatric intensive care (CHiP): study protocol

Background

There is increasing evidence that tight blood glucose (BG) control improves outcomes in critically ill adults. Children show similar hyperglycaemic responses to surgery or critical illness. However it is not known whether tight control will benefit children given maturational differences and different disease spectrum.

Methods/Design

The study is an randomised open trial with two parallel groups to assess whether, for children undergoing intensive care in the UK aged ≤ 16 years who are ventilated, have an arterial line in-situ and are receiving vasoactive support following injury, major surgery or in association with critical illness in whom it is anticipated such treatment will be required to continue for at least 12 hours, tight control will increase the numbers of days alive and free of mechanical ventilation at 30 days, and lead to improvement in a range of complications associated with intensive care treatment and be cost effective. Children in the tight control group will receive insulin by intravenous infusion titrated to maintain BG between 4 and 7.0 mmol/l. Children in the control group will be treated according to a standard current approach to BG management. Children will be followed up to determine vital status and healthcare resources usage between discharge and 12 months post-randomisation. Information regarding overall health status, global neurological outcome, attention and behavioural status will be sought from a subgroup with traumatic brain injury (TBI). A difference of 2 days in the number of ventilator-free days within the first 30 days post-randomisation is considered clinically important. Conservatively assuming a standard deviation of a week across both trial arms, a type I error of 1% (2-sided test), and allowing for non-compliance, a total sample size of 1000 patients would have 90% power to detect this difference. To detect effect differences between cardiac and non-cardiac patients, a target sample size of 1500 is required. An economic evaluation will assess whether the costs of achieving tight BG control are justified by subsequent reductions in hospitalisation costs.

Discussion

The relevance of tight glycaemic control in this population needs to be assessed formally before being accepted into standard practice.

Trial Registration

Current Controlled Trials ISRCTN61735247     

Characterization of mycobacterial virulence genes through genetic interaction mapping

We have previously shown that approximately 5% of the genes encoded by the genome of Mycobacterium tuberculosis are specifically required for the growth or survival of this bacterium during infection. This corresponds to hundreds of genes, most of which have no identifiable function. As a unique approach to characterize these genes, we developed a method to rapidly delineate functional pathways by identifying mutations that modify each other's phenotype, i.e., "genetic interactions". Using this method, we have defined a complex set of interactions between virulence genes in this pathogen, and find that the products of unlinked genes associate to form multisubunit transporters that are required for bacterial survival in the host. These findings implicate a previously undescribed family of transport systems in the pathogenesis of tuberculosis, and identify genes that are likely to function in the metabolism of their substrates. This method can be readily applied to other organisms at either the single pathway level, as described here, or at the system level to define quantitative genetic interaction networks.     

A simple and sensitive high-performance liquid chromatographic method for the determination of vinflunine and 4-O-deacetylvinflunine from human blood

Vinflunine (VFL) is the first bifluorinated tubulin-targeted agent obtained through a semi synthetic process using superacidic chemistry. Pharmacologic models evidenced a high degree of activity from several cancer lines. The intravenous formulation of VFL (Javlor, Pierre Fabre Medicament, Boulogne, France) is registered for bladder cancer and is undergoing Phase III trials for nonsmall cell lung and breast cancer. To support most of the pharmacokinetic studies in humans, a sensitive high-performance liquid chromatography bioanalytical method coupled with ultraviolet detection was developed and validated for the simultaneous quantification of VFL and its active metabolite 4-O-deacetylvinflunine. The two compounds, together with 17-bromovinorelbine, used as an internal standard, were extracted from blood (1 mL) by a liquid-liquid process under basic conditions using diethyl ether. The organic phase was then back-extracted with HCl 0.1 mol/L. Analysis was performed through a cyano column and detection was set at 268 nm. Total analysis run time was less than 15 minutes. The assay was sensitive for the two compounds to at least 2 ng/mL and calibration curves were linear up to 200 ng/mL. The between-run imprecision and the mean inaccuracy were lower than 7% and 8.3%, respectively. Blood samples were stable when stored at -70°C over 24 months. The long-term reproducibility and the suitability of this analytical method were demonstrated through the analysis of about 6000 biologic samples during the clinical development of intravenous VFL. This method is adequately sensitive to monitor the blood concentrations observed at the recommended dose defined in a clinical setting.     

A comparison of propofol and amobarbital for use in the Wada test

129 Wada procedures were reviewed to examine the suitability of propofol (n=54) as a replacement to amobarbital (n=75) for use as an anaesthetic in the Wada test. Suitability was considered with respect to length of hemiplegia induced, the frequency of side effects and patient memory scores. Data was retrospectively collected from records of patients who had undergone the Wada procedure between 2004 and 2009 in Beaumont Hospital, Dublin. No significant differences were found between the two drugs on any of the measures. The results suggest that propofol represents a suitable alternative to amobarbital for use in the Wada procedure.     

Complex decisions: correlates of injectable contraceptive discontinuation following HIV-1 seroconversion in an HIV prevention trial

Contraceptive adherence during acute and recent HIV-1 infection is important to maternal and child health given the elevated risk of vertical HIV-1 transmission and additional complications of pregnancy. Injectable contraception (IC) is the most common non-barrier modern contraception method used in sub-Saharan Africa (SSA). Adherence to IC after HIV-1 seroconversion is not well understood. We examined factors associated with IC discontinuation among women in SSA diagnosed with HIV-1 infection while participating in a clinical trial of biomedical HIV-1 prevention. After diagnosis with HIV-1 infection in the VOICE trial, 255 women from South Africa, Uganda, and Zimbabwe enrolled in a longitudinal observational study (MTN-015). Contraceptive method was assessed at MTN-015 baseline and at 3, 12, and 24 months post-seroconversion. Correlates of IC discontinuation were examined by Cox proportional hazard modeling. IC use was reported at baseline by 78% of women enrolled (198/255), of which 92% (182/198) completed at least one follow-up visit. Two-thirds of women (66%, 121/182) continued on IC during the follow-up period (median 24 months). Lower rates of IC discontinuation were observed in women who reported having had at least one child (HR 0.39, 95% CI 0.20–0.82) or earning a personal income (HR 0.51, 95% CI 0.30–0.87) at baseline. These findings suggest that many women with HIV-1 infection face complex decision-making regarding family planning in the years that follow seroconversion and highlight that some women may discontinue IC use despite on-site provision of family planning services. Understanding the broader context of family planning choices in recently seroconverted women may be key to more effective linkages between family planning services and HIV-1 testing and care.     

Association of the joint effect of menopause and hormone replacement therapy and cancer in African American women: the Jackson Heart Study

Cancer is the second leading cause of death in the US and in Mississippi. Breast cancer (BC) is the most common cancer among women, and the underlying pathophysiology remains unknown, especially among African American (AA) women. The study purpose was to examine the joint effect of menopause status (MS) and hormone replacement therapy (HRT) on the association with cancers, particularly BC using data from the Jackson Heart Study. The analytic sample consisted of 3202 women between 35 and 84 years of which 73.7% and 22.6% were postmenopausal and on HRT, respectively. There were a total of 190 prevalent cancer cases (5.9%) in the sample with 22.6% breast cancer cases. Menopause (p<0.0001), but not HRT (p=0.6402), was independently associated with cancer. Similar results were obtained for BC. BC, cancer, hypertension, type 2 diabetes, prevalent cardiovascular disease, physical activity and certain dietary practices were all significantly associated with the joint effect of menopause and HRT in the unadjusted analyses. The family history of cancer was the only covariate that was significantly associated with cancer in the age-adjusted models. In examining the association of cancer and the joint effect of menopause and HRT, AA women who were menopausal and were not on HRT had a 1.97 (95% CI: 1.15, 3.38) times odds of having cancer compared to pre-menopausal women after adjusting for age; which was attenuated after further adjusting for family history of cancer. Given that the cancer and BC cases were small and key significant associations were attenuated after adjusting for the above mentioned covariates, these findings warrant further investigation in studies with larger sample sizes of cancer (and BC) cases.     

Clinical Review: Familial Mediterranean Fever—An Overview of Pathogenesis,Symptoms, Ocular Manifestations,and Treatment

Familial Mediterranean fever is an autoinflammatory multisystem disease, which most commonly affects patients from the Mediterranean basin. This review discusses the common polymorphisms in the MEFV gene as well as the role of pyrin in disease pathogenesis. Patients with familial Mediterranean fever typically develop peritonitis, pleuritis, arthritis, and fever. In addition, a number of authors have reported ophthalmic features. These case reports and series are further explored in this review. Colchicine has transformed the prognosis for patients with familial Mediterranean fever. The rationale for the use of colchicine, as well as the evidence for newer biologic agents is also covered.     

Patients with psoriasis and their compliance with medication.

BACKGROUND: Poor compliance with treatment advice in chronic conditions, such as psoriasis, represents a major challenge to health care professionals. Previous research suggests that the rate of noncompliance in chronic conditions may be as high as 40%. OBJECTIVE: This study was designed to examine self-reported compliance in patients with psoriasis. METHODS: We undertook an anonymous postal survey sent to consecutive patients with psoriasis attending a tertiary psoriasis specialty clinic. RESULTS: Thirty-nine percent of participants reported that they did not comply with the treatment regimen recommended. The noncompliant group had a higher self-rated severity of psoriasis (t = -2.16, P =. 03), were younger (t = 3.28, P =.001), and had a younger age at onset (t = 2.35, P =.02) than those who were compliant. The noncompliant group reported that psoriasis had a greater impact on daily life (t = -2.23, P =.028), but general well-being was not significantly different from those who complied (t =.47, P = not significant). CONCLUSION: Patients who reported intentional noncompliance with treatment advice were more likely to believe that both psoriasis and its treatment interfered with their quality of life but not overall well-being. The impact of treatment on daily life highlights the importance of joint decision making in planning treatment.