Self-reported non-adherence to ART and virological outcome in a multiclinic UK study

Adherence is of fundamental importance to ART success. We examined the association of self-reported non-adherence with demographic factors, health and behaviour issues, and virological outcome, in a multi-clinic study. Seven hundred and seventy-eight HIV patients in five clinics in London and Brighton completed a questionnaire on adherence and HIV/health issues at baseline in 2005/6. For 486 subjects taking ART, non-adherence in the past week was defined as: (A)>or=1 dose missed or taken incorrectly (wrong time/circumstances); (B)>or=1 dose missed; (C)>or=2 doses missed. Questionnaire data were matched with routine treatment and virology data for consenting subjects (61.4%). We assessed four virological outcomes in 307 of 486 patients: (i) VL>50c/mL using latest VL at the questionnaire and excluding patients starting HAART<24 weeks ago; (ii) VL>50c/mL using the first VL from 6 to 12 months post-questionnaire; (iii) any VL>50c/mL from 6 to 12 months post-questionnaire; (iv) among patients with VL<50c/mL at questionnaire, time to first subsequent VL>50c/mL over two years follow up. Non-adherence was reported by 278 (57.2%), 102 (21.0%) and 49 (10.1%) of 486 patients, for definitions A, B and C, respectively. Non-adherence declined markedly with older age, and tended to be more commonly reported by Black patients, those born outside the UK, those with greater psychological symptoms and those with suicidal thoughts. There was a weaker association with physical symptoms and no association with gender/sexuality, education, unemployment, or risk behaviour (p>0.1). In logistic regression analyses, younger age, non-UK birth and psychological variables were independent predictors of non-adherence [e.g., for non-adherence B: odds ratios (95% CI) were 0.95 (0.92, 0.98) for every year older age; 1.6 (1.0, 2.5) for non-UK born; 2.3 (1.5, 3.7) for suicidal thoughts]. Non-adherence was associated with poorer virological outcome; the most consistent association was for definition C. Among 255 patients with VL<50c/mL at baseline, non-adherence definition C was independently associated with subsequent VL>50c/mL [adjusted hazard ratio (95% CI) 3.2 (1.5, 7.2)]. Non-UK birth and psychological symptoms predicted non-adherence, but the most striking association was with younger age. Age should be an important consideration in clinical strategies to minimise non-adherence and in decisions regarding ART initiation. A simple measure of non-adherence can identify patients at risk of poorer virological outcome.

The use and abuse of hypothesis tests: how to present P values

This overview highlights some of the key issues involved in performing and interpreting hypothesis tests. We describe the general approach taken in performing a hypothesis test with a focus on how to state the null and alternative hypothesis, and why two-sided tests are usually more appropriate than one-sided tests. We describe best practice techniques in performing and presenting the results of hypothesis tests. We recommend that, alongside any p-values, authors should also present estimates of the size of any treatment effects and their confidence intervals. Furthermore, they should specify the exact p-value rather than using terms such as 'NS' or the commonly used asterix notation. We discuss other pitfalls that are encountered at the analysis stage such as the use of repeated observations on individuals, the use of multiple tests on the data and the erroneous use of parametric tests when data are not normally distributed and vice versa. We highlight these points using two different examples: one looking at the use of compression stockings for preventing the occurrence of DVT on long-haul flights and a second hypothetical study comparing laser versus surgery techniques for the removal of varicose veins.

Comparison of nucleoside reverse transcriptase inhibitor use as part of first-line therapy in a Serbian and a UK HIV clinic

BACKGROUND

Use of dideoxynucleoside reverse transcriptase inhibitors (dNRTIs) may lead to increased mitochondrial toxicity. We compared nucleoside reverse transcriptase inhibitor (NRTI) use as part of antiretroviral therapy (ART) in two HIV clinics: one in a low-middle income (HIV Centre Belgrade [HCB], Serbia) and one a high income (ICDC, Royal Free Hospital, London, UK) country.

METHODS

Antiretroviral naïve patients starting ART from 2003 to 2005 were included. Specific NRTIs were compared between centers, focusing on dNRTI use. Kaplan-Meier estimates of the percentage of patients making changes to their NRTI backbone (a) for any reason or (b) for mitochondrial toxicity (peripheral neuropathy, pancreatitis, lactic acidosis) were calculated.

RESULTS

Of 287 HCB patients, 89 (31.0%) received didanosine (ddI)-containing, 39 (13.6%) stavudine (d4T)-containing, and 39 (13.6%) ddI+d4T-containing regimens; for 539 ICDC patients, these were 18 (3.3%), 66 (12.2%), and 0 (0.0%), respectively (p < .0001). After 12 months, 57.5% and 52.6% at HCB and ICDC had switched their NRTI backbone. This was reduced to 34.5% at HCB after excluding changes due to drug supply interruption and to 11.2% and 1.3% at HCB and ICDC after changes were made for mitochondrial-related reasons. At 6 months, 73/80 (91.3%) and 385/488 (78.9%) had viral load below 50 copies/mL at HCB and ICDC, respectively.

CONCLUSION

Patients treated at HCB faced higher levels of mitochondrial-related toxicity, likely due to greater dNRTI use.

The associations between age and the development of laboratory abnormalities and treatment discontinuation for reasons other than virological failure in the first year of highly active antiretroviral therapy

OBJECTIVE

The aim of this study was to describe the relationship between age and the time to treatment discontinuation in the absence of virological failure as well as the development of specific laboratory abnormalities, in patients starting highly active antiretroviral therapy (HAART) for the first time.

METHODS

Analyses included 8708 antiretroviral-naïve patients from the UK Collaborative HIV Cohort (CHIC) study who started HAART from 1998 onwards. We considered time to the first discontinuation of any drug in the initial HAART regimen for reasons other than virological failure; the association between this and age at the start of HAART was determined using proportional hazards regression after adjustment for potential confounders. The incidence of specific laboratory abnormalities in the first year after starting HAART was compared in those of different ages using multiple logistic regression.

RESULTS

A total of 2650 patients discontinued at least one drug in their HAART regimen in the first year for reasons other than virological failure; after controlling for confounders, those aged < 30 years at the time of starting HAART were more likely to discontinue than those aged 30-39 years [relative hazard (RH) 1.12; 95% confidence interval (CI) 1.01, 1.24] as were those aged > or = 50 years (RH 1.14; 95% CI 1.00, 1.31). There were strong associations between greater age and raised total cholesterol, decreased haemoglobin and raised triglycerides over the first year, although the latter disappeared after adjustment for pre-HAART levels, suggesting that this finding reflected higher pre-HAART triglyceride levels in older individuals.

CONCLUSIONS

Continued attempts to improve the tolerability of HAART regimens may help to sustain the good outcomes in all age groups over the longer term.

Diabetes, colorectal cancer and cyclooxygenase 2 inhibition

Diabetes is a risk factor for cancer and specifically colorectal cancer. It is also associated with increased cancer mortality. Aspirin, non-steroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase 2 (Cox-2) inhibitors have been shown to decrease the incidence of colorectal cancer. This effect may be mediated by inhibiting prostaglandin synthesis. Long-term use of high-dose aspirin and NSAIDs is associated with significant gastrointestinal side effects. Unfortunately, the use of Cox-2 inhibitors is associated with an increased incidence of acute myocardial infarction and death from cardiovascular disease. The increased risk of cardiovascular disease in patients with diabetes results in the loss of the potential to use Cox-2 inhibitors for cancer chemoprophylaxis. Until a safer type of Cox-2 inhibitor is available, or low-dose aspirin is evaluated for chemoprophylaxis, a more intense screening programme for colorectal cancer may be appropriate for patients with diabetes, especially men. Healthcare professionals managing patients with diabetes should be aware of the increased risk of this type of cancer.

An audit of viral load in one clinical population to describe features of viraemic patients on antiretroviral therapy

OBJECTIVES

To assess the prevalence of an undetectable viral load (VL) (<50 HIV-1 RNA copies/mL) in a clinical population and to identify those viraemic and at risk of failing antiretroviral therapy (ART).

METHODS

An audit of a complete clinical population on 1 January 2005 via a clinical database and clinical note review.

RESULTS

On 1 January 2005, 1910 patients were under care; 1229/1332 (92%) of those exposed to ART for >16 weeks had a VL of <50 copies/mL. We examined 49/56 case notes of viraemic patients to identify explanations for viraemia. Common reasons included previous initial mono- or dual therapy, adherence problems, more advanced HIV disease, concomitant medications, physical and mental health issues and being less well linked into the service. A review of these patients' current status on 1 April 2007 showed that six of the 49 had since died. However, of those still alive, 20 (47%) had a VL <500 copies/mL.

CONCLUSIONS

The proportion of patients on ART with detectable viraemia is low in current clinical practice. New drugs may help those who are failing because of resistance. However, there is a small minority of patients who, for various reasons, appear unable to maintain sufficient adherence to ART.

Prognosis in patients with transient ischaemic attack (TIA) and minor stroke attending TIA services in the North West of England: the NORTHSTAR Study

BACKGROUND

The ABCD2 score predicts stroke risk within a few days of transient ischaemic attack (TIA). It is not clear whether the predictive value of the ABCD2 score can be generalised to UK TIA services, where delayed presentation of TIA and minor stroke are common. We investigated prognosis, and the use of the ABCD2 score, in patients attending TIA services in the North West of England with a diagnosis of TIA or minor stroke.

METHODS

711 patients with TIA or minor stroke were prospectively recruited from five centres (median duration from index event to recruitment 15 days). The primary outcome was the composite of incident TIA, stroke, acute coronary syndrome or cardiovascular death at the 3 month follow-up. Prognostic factors were analysed using Cox proportional hazards regression.

RESULTS

The primary outcome occurred in 126 (18%) patients. Overall, there were 30 incident strokes. At least one incident TIA occurred in 100 patients (14%), but only four had a subsequent stroke. In multifactorial analyses, the ABCD2 score was unrelated to the risk of the primary outcome, but predicted the risk of incident stroke: score 4-5: hazard ratio (HR) 3.4 (95% CI 1.0 to 12); score 6-7: HR 4.8 (1.3 to 18). Of the components of the ABCD2 score, unilateral motor weakness predicted both the primary outcome (HR 1.8 (1.2 to 2.8)) and stroke risk (HR 4.2 (1.3 to 14)).

CONCLUSIONS

In patients attending typical NHS TIA services, the risk of incident stroke was relatively low, probably reflecting delays to assessment. Current provision of TIA services, where delayed presentation to "rapid access" TIA clinics is common, does not appear to provide an appropriate setting for urgent evaluation, risk stratification or timely secondary prevention for those who may be at highest risk.

How good are systemic symptoms and blood inflammatory markers at detecting individuals with tuberculosis?

SETTING

The diagnosis of tuberculosis (TB) may be rejected in the absence of symptoms such as fever, sweats or weight loss.

OBJECTIVES

To determine how frequently these features and blood test evidence of inflammation were absent in individuals with TB.

METHODS

Prospective cohort study of 175 unselected subjects diagnosed with TB at a UK TB service between 2003 and 2006.

RESULTS

Eight (5%) subjects identified by screening and 24 (14%) without culture confirmation were excluded. Of the remaining 143, fever, sweats or weight loss were absent in respectively 37%, 39% and 38%. All three symptoms were absent in 25%. In 88 subjects with pulmonary disease, all three symptoms were absent in 20% (10% of smear-positive cases). Overall, C-reactive protein was normal in 15%, erythrocyte sedimentation rate in 21% and lactate dehydrogenase in 55%. In a multivariable model, factors associated with absent symptoms included drug-resistant TB (adjusted odds ratio [aOR] 3.58, P = 0.004) and female sex (aOR 3.15, P = 0.004).

CONCLUSIONS

In our population, TB, including pulmonary disease, frequently presented without fever, sweats or weight loss and with normal blood inflammatory markers. This information is of as much relevance to policy makers seeking to improve active case detection as to clinicians and the general public.

Clinical application of a rapid lung-orientated immunoassay in individuals with possible tuberculosis

BACKGROUND

Immunological ex vivo assays to diagnose tuberculosis (TB) have great potential but have largely been blood-based and poorly evaluated in active TB. Lung sampling enables combined microbiological and immunological testing and uses higher frequency antigen-specific responses than in blood.

METHODS

A prospective evaluation was undertaken of a flow cytometric assay measuring the percentage of interferon-gamma synthetic CD4+ lymphocytes following stimulation with purified protein derivative of Mycobacterium tuberculosis (PPD) in bronchoalveolar lavage fluid from 250 sputum smear-negative individuals with possible TB. A positive assay was defined as >1.5%.

RESULTS

Of those who underwent lavage and were diagnosed with active TB, 95% (106/111) had a positive immunoassay (95% CI 89% to 98%). In 139 individuals deemed not to have active TB, 105 (76%) were immunoassay negative (95% CI 68% to 82%). Of the remaining 24% (34 cases) with a positive immunoassay, a substantial proportion had evidence of untreated TB; in two of these active TB was subsequently diagnosed. Assay performance was unaffected by HIV status, disease site or BCG vaccination. In culture-positive pulmonary cases, response to PPD was more sensitive than nucleic acid amplification testing (94% vs 73%). The use of early secretory antigen target-6 (ESAT-6) responses in 71 subjects was no better than PPD, and 19% of those with culture-confirmed TB and a positive PPD immunoassay had no detectable response to ESAT-6.

CONCLUSIONS

These findings suggest that lung-orientated immunological investigation is a potentially powerful tool in diagnosing individuals with sputum smear-negative active TB, regardless of HIV serostatus.

No association between HIV disease and its treatment and thyroid function

OBJECTIVES

The aims of the study were (i) to investigate the prevalence of overt and subclinical thyroid disease in HIV-positive patients in a London teaching hospital; (ii) to determine risk factors associated with the development of thyroid dysfunction, including highly active antiretroviral therapy (HAART) and individual antivirals, and (iii) to determine the occurrence of thyroid dysfunction longitudinally over 3 years.

METHODS

The study consisted of retrospective analyses of thyroid function tests (TFT) in HIV-positive patients. The period prevalence of and factors associated with clinical and subclinical thyroid dysfunction were investigated. Patients with normal TFT but previous thyroid disease were identified from pharmacy records and included in the overt category.

RESULTS

A total of 1565 patients (73% of the clinic population) had at least one TFT taken since 2001. Overall, 3584 samples were analysed. Of the patients included in the study, 1233 (79%) were male, 1043 (66%) were white and 365 (23%) were black African, and in 969 (62%) the main risk for HIV was homosexual sex. Median age at baseline was 37 years. Nine hundred patients (58%) were on HAART at the start of the study. Thirty-nine (2.5%) were found to have overt hypothyroidism, and eight (<1%) had overt hyperthyroidism. Sixty-one (4%) had subclinical hypothyroidism, five (<1%) had subclinical hyperthyroidism and 263 (17%) had a nonthyroidal illness. A normal TFT was obtained for 1118 patients (75.5%). Multivariate analysis suggested that no independent variables were significantly associated with overt hypothyroidism, including HAART and stavudine use specifically. Repeated measurements over 3 years were available for 825 patients and only eight new cases (1%) of overt thyroid disease occurred.

CONCLUSIONS

The prevalence of overt thyroid disease was low in this cohort, suggesting that screening is not warranted.

Comparison of in vitro and in vivo properties of [99mTc]cRGD peptides labeled using different novel Tc-cores

AIM

The alfa(v)beta(3) integrin is involved in angiogenesis and tumor metastasis. Arginine-glycine-aspartic acid (RGD)-peptides bind with high affinity to this integrin. This study compares the influence of (99m)Tc-labeling applying novel Technetium-cores on imaging characteristics of the radiolabeled peptide.

METHODS

Different peptide conjugates based on the cyclic pentapeptide c(RGDyK) (cRGD) were prepared and characterized (HYNIC-, Cys-, L2- and Pz1-cRGD). Radiolabeling experiments using different coligands for HYNIC-cRGD, the (99m)Tc(CO)(3) metal fragment for PZ-1-cRGD (pyrazolyl-derivative), the Tc-nitrido-core using a phosphine-coligand (PNP) for Cys-cRGD and an isonitrile-conjugate (L2-cRGD) together with a NS(3)-coligand (4+1 concept) were performed and showed labeling yields >90% at high specific activities.

RESULTS

A high in vitro stability was observed, plasma protein binding and lipophilicity varied considerably between different radiolabeled cRGD conjugates. Experiments on biological activity of the radiolabeled peptides using alfa(v)beta(3) positive (M21) and negative (M21L) tumor cells did show specific uptake of various conjugates. Studies in tumor bearing animals revealed significant differences between different conjugates concerning pharmacokinetic behavior (predominant renal excretion to considerable hepatobiliary clearance) as well as tumor uptake (0.2-2.7%ID/g). Highest specific tumor uptake and tumor/background values were found for [(99m)Tc]EDDA/HYNIC-c(RGDyK), [(99m)Tc]Nitrido-PNP-Cys-c(RGDyK) and [(99m)Tc(CO)(3)]-Pz1-c(RGDyK).

CONCLUSIONS

Using novel Tc-cores such as the (99m)Tc(CO)(3) metal fragment, Tc-nitrido- and the 4+1 concept peptides could be labeled with [(99m)Tc]technetium at high specific activities resulting in complexes with high stability, but binding moieties have to be optimized especially concerning hydrophilicity resulting in renal rather than hepatobiliary excretion. This comparative study underlines that peptide labeling strategies using (99m)Tc have to be properly selected and optimized. Different in vitro assays are necessary to predict targeting properties in vivo.

Treatment outcomes amongst previously antiretroviral-naïve HIV-infected patients starting lopinavir/ritonavir-containing antiretroviral regimens at the Royal Free Hospital*

OBJECTIVE

To describe outcomes in patients starting first-line antiretroviral regimens including lopinavir/ritonavir (LPV/r) in a routine clinic setting.

METHODS

Previously naïve patients starting LPV/r-containing antiretroviral therapy were included in the study. Virological failure was defined as the first of two viral loads >500 HIV-1 RNA copies/mL more than 6 months after starting LPV/r. Cumulative percentages experiencing virological failure were calculated using Kaplan-Meier methods.

RESULTS

A total of 195 individuals had a median follow-up time of 1.7 years. At 48 weeks, 87.9, 77.4 and 71.6% of patients with pretreatment CD4 counts of <50, 50-200 and >200 cells/microL, respectively, remained on LPV/r. By 48, 72 and 96 weeks, 2.2, 3.0 and 5.0% of patients, respectively, had experienced virological failure, ignoring treatment changes but censoring follow-up at discontinuation of all antiretrovirals; these percentages became 24.0, 33.7 and 42.3% when LPV/r discontinuation was considered as virological failure. Censoring those who stopped LPV/r with a viral load <50 copies/mL and considering as virological failures those who stopped LPV/r with a viral load >50 copies/mL gave 12.1, 14.6 and 17.0% virological failure at 48, 72 and 96 weeks, respectively. Median CD4 count increases at 24, 48 and 72 weeks were 167, 230 and 253 cells/microL, respectively.

CONCLUSIONS

Few patients experienced virological failure whilst on a LPV/r-based regimen, although it was not uncommon for patients in our clinic with higher baseline CD4 counts to discontinue LPV/r.

Haemoglobin and albumin as markers of HIV disease progression in the highly active antiretrovial therapy era: relationships with gender

OBJECTIVES

The aims of the study were to describe gender differences in haemoglobin and albumin and to investigate the prognostic value of these measurements in relation to highly active antiretroviral therapy (HAART).

METHODS

Anaemia was defined as haemoglobin <13.5 g/dL for men and <11.5 g/dL for women. Albumin <35 g/L was defined as hypoalbuminaemia. Proportional hazards models were used to describe relationships between these markers and HIV progression and death.

RESULTS

A total of 291 patients had pre-HAART and 1-year measurements. Mean haemoglobin and albumin levels pre-HAART were lower in women than in men (haemoglobin: 11.2 vs 13.2 g/dL, respectively, P<0.0001; albumin: 37.4 vs 40.2 g/L, respectively, P<0.0001), and a higher proportion of women were anaemic and hypoalbuminaemic compared with men. Despite a rise in both markers in the first year on HAART, mean haemoglobin levels remained lower by 2.08 g/dL (P<0.0001) and albumin by 2.88 g/L (P<0.0001) in women. In the 495 patients included in this analysis, haemoglobin and albumin levels were both significantly related to short-term risk of AIDS and death independently of CD4 count [hazards ratio (HR)=0.73/g/dL higher haemoglobin, 95% confidence interval (CI) 0.55-0.82, P<0.0001 and HR=0.87/g/L higher albumin, 95% CI 0.83-0.91, P<0.0001]. The prognostic value did not differ by gender.

CONCLUSIONS

Women were more likely to be anaemic and/or hypoalbuminaemic pre-HAART, but post-HAART increases were similar to those in men. Both haemoglobin and albumin were strong independent prognostic factors for risk of AIDS and death, regardless of gender.

Effects of highly active antiretroviral therapy on paediatric metabolite levels

OBJECTIVES

Highly active antiretroviral therapy (HAART) has extended survival of HIV-infected children into adulthood, raising concerns about long-term metabolic changes in childhood.

METHODS

A longitudinal study of metabolite levels in paediatric HIV-infected patients before and after starting HAART (January 2000 to June 2003). The effects of HAART on nonfasting blood levels of total (TC), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol, cholesterol ratio and lactate were analysed using mixed-effects regression.

RESULTS

A total of 146 children attended 1208 appointments (median 6.7/child). Of these, 99 (68%) were African. At baseline, 75 (51%) were on HAART and had higher TC (4.19 vs 3.49 mmol/L, P<0.0001), HDL (1.03 vs 0.82 mmol/L, P<0.0001), and LDL (2.54 vs 2.11 mmol/L, P=0.0003) than those not on HAART. Metabolites increased with time on HAART exposure and then stabilized. At 2 years, TC had increased by 0.93 mmol/L (P<0.0001), with 29 children (20%) having repeated TC levels above the 95th centile. LDL and HDL had increased by 0.69 and 0.31 mmol/L at 2 years, respectively (both P<0.0001). Lactates declined with increasing age (-0.06 mmol/L/year, P=0.0001).

CONCLUSIONS

This is the first cohort study to demonstrate significant elevations of HDL as well as LDL in children on HAART. This rise in cardio-protective HDL may represent a positive effect of treatment.

Adverse events and treatment interruption in tuberculosis patients with and without HIV co-infection

BACKGROUND

Serious treatment associated adverse events are thought to occur more frequently in individuals with tuberculosis (TB) who are co-infected with HIV. A study was undertaken to assess the frequency of serious (grade III/IV) adverse events and interruption of anti-TB treatment in the era of effective antiretroviral therapy.

METHODS

The incidence of serious adverse events was retrospectively compared in 312 individuals treated for TB, 156 of whom were co-infected with HIV.

RESULTS

111 HIV infected individuals (71%) received highly active antiretroviral therapy at the same time as anti-TB treatment. Serious adverse events were recorded in 40% HIV infected and 26% HIV uninfected individuals (p = 0.008). Peripheral neuropathy and persistent vomiting were more common in co-infected patients (p<0.001; p = 0.006), although all cause interruption of anti-TB treatment occurred with similar frequency in the two groups (13% in HIV infected patients and 15% in HIV uninfected patients; p = 0.74). In 85% of HIV infected patients and 87% of HIV uninfected individuals this was due to hepatotoxicity, which typically presented within 2 months of starting treatment. The median delay in restarting treatment was 4 weeks, so most individuals required full TB re-treatment.

CONCLUSION

Despite a greater rate of serious (grade III/IV) adverse events among HIV infected individuals, discontinuation of anti-TB treatment occurred with a similar frequency in HIV infected and HIV uninfected individuals.

Systemic sclerosis associated pulmonary hypertension: improved survival in the current era

OBJECTIVES

To measure survival, haemodynamic function and functional class in patients with systemic sclerosis associated pulmonary arterial hypertension (SSc-PAH) in two treatment eras.

METHODS

Six year longitudinal study of 92 consecutive patients with SSc-PAH diagnosed by cardiac catheterisation. Data were collected both prospectively and retrospectively. Patients were given basic treatment (diuretics, digoxin, oxygen and warfarin). Where clinically indicated, a prostanoid was used as advanced treatment (historical control group). From 2002, the range of treatments available expanded to include bosentan, which was generally the preferred treatment (current treatment era group). Survival was measured from the date of diagnosis of pulmonary hypertension by cardiac catheterisation. Six minute walking distance and haemodynamic function were measured at the time of diagnosis and at least one month after treatment was started.

RESULTS

The historical control group comprised 47 patients, all of whom received basic treatment; 27 of these were also treated with prostanoids. The current treatment era group comprised 45 patients, all of whom received bosentan as preferred treatment. Kaplan-Meier survival in the historical control group was 68% at one year and 47% at two years. Survival in the current treatment era group was 81% and 71% (p = 0.016) at one and two years, respectively. Pulmonary vascular resistance increased in the historical control group (by 147 dyn.s.cm(-5)), whereas in the current treatment era group, it remained stable over an average of nine months (decrease of 16 dyn x s x cm(-5), p < 0.006).

CONCLUSION

Survival of selected patients with SSc-PAH has improved in the current treatment era. In contrast to patients treated historically with basic drugs and prostanoids, patients treated in the current treatment era had improved survival associated with a lack of deterioration in cardiac haemodynamic function.

Energy intake and physical activity in Pima Indians: comparison with energy expenditure measured by doubly-labeled water

To test the validity of survey techniques for measuring diet and activity patterns of Pima Indians, sequential 24-hour recalls, a food frequency questionnaire (FFQ), and an activity questionnaire were compared to free-living energy expenditure. Total energy expenditure (TEE) measured by doubly labeled water was 13.27 +/- 2.95 MJ/d for the 12 males (mean +/- SD: 35 +/- 14 yr; 97 +/- 35 kg; 32 +/- 9% body fat) and 11.67 +/- 1.85 MJ/d for the 9 females (31 +/- 13 yr; 106 +/- 32 kg; 49 +/- 6% body fat). Energy intake assessed by 24-hour recall was 13.59 +/- 7.81 MJ/d for men and 9.29 +/- 2.77 MJ/d for women, compared to 12.84 + 2.85 and 9.40 + 2.61 MJ/d for men and women, respectively, by FFQ. Both dietary methods indicated significant underreporting by women when compared to TEE. Energy intake assessed by FFQ was significantly correlated with TEE (r=0.48, p=0.03). This was true with 24-hour recall energy intake only when data from two extremely large alcohol consumers were eliminated (r=0.64, p=0.03, N=19). Although a low level of activity was apparent, the activity questionnaire produced significant correlations with measurements of energy expenditure and therefore represents an important tool for examining the relationship between physical activity and diseases.

Virological response to highly active antiretroviral therapy is unaffected by antituberculosis therapy

We compared 156 human immunodeficiency virus (HIV)-infected patients who had tuberculosis with control populations of similar size. Of 111 patients with HIV infection and tuberculosis who received highly active antiretroviral therapy (HAART) and therapy for tuberculosis concurrently, 92 (83%) achieved or maintained virus loads of <50 copies/mL, and 99 (89%) achieved or maintained a >or=2 log10 reduction in virus load after 6 months. Virological response and changes in CD4 cell count were equivalent to those in 111 matched HIV-infected subjects without tuberculosis starting HAART. Tuberculosis recurrence rates were similar to those found in an HIV-uninfected population of 156 subjects (3% and 1%, respectively). Treatment for HIV and tuberculosis does not compromise outcomes for either disease.

A randomised phase II study of interleukin-1 receptor antagonist in acute stroke patients

OBJECTIVES

The cytokine interleukin (IL)-1 mediates ischaemic brain damage in rodents. The endogenous, highly selective, IL-1 receptor antagonist (IL-1ra) protects against ischaemic cerebral injury in a range of experimental settings, and IL-1ra causes a marked reduction of cell death when administered peripherally or at a delay in transient cerebral ischaemia. We report here the first randomised, double blind, placebo controlled trial of recombinant human IL-1ra (rhIL-1ra) in patients with acute stroke.

METHODS

Patients within 6 hours of the onset of symptoms of acute stroke were randomised to rhIL-1ra or matching placebo. Test treatment was administered intravenously by a 100 mg loading dose over 60 seconds, followed by a 2 mg/kg/h infusion over 72 h. Adverse events and serious adverse events were recorded for up to 3 months, serial blood samples were collected for biological markers up to 3 months, and 5-7 day brain infarct volume was measured by computed tomography.

RESULTS

No adverse events were attributed to study treatment among 34 patients randomised. Markers of biological activity, including neutrophil and total white cell counts, C reactive protein, and IL-6 concentrations, were lower in rhIL-1ra treated patients. Among patients with cortical infarcts, clinical outcomes at 3 months in the rhIL-1ra treated group were better than in placebo treated.

CONCLUSIONS

These data suggest that rhIL-1ra is safe and well tolerated in acute stroke. In addition, rhIL-1ra exhibited biological activity that is relevant to the pathophysiology and clinical outcome of ischaemic stroke. Our findings identify rhIL-1ra as a potential new therapeutic agent for acute stroke.

Genetic and structural analysis of the Bacteroides conjugative transposon CTn341

The genetic structure and functional organization of a Bacteroides conjugative transposon (CTn), CTn341, were determined. CTn341 was originally isolated from a tetracycline-resistant clinical isolate of Bacteroides vulgatus. The element was 51,993 bp long, which included a 5-bp coupling sequence that linked the transposon ends in the circular form. There were 46 genes, and the corresponding gene products fell into three major functional groups: DNA metabolism, regulation and antibiotic resistance, and conjugation. The G + C content and codon usage observed in the functional groups suggested that the groups belong to different genetic lineages, indicating that CTn341 is a composite, modular element. Mutational analysis of genes representing the different functional groups provided evidence for the gene assignments and showed that the basic conjugation and excision genes are conserved among Bacteroides spp. A group IIA1 intron, designated B.f.I1, was found to be inserted into the bmhA methylase gene. Reverse transcriptase PCR analysis of CTn341 RNA showed that B.fr.I1 was functional and was spliced out of the bmhA gene. Six related CTn-like elements were found in the genome sequences of Bacteroides fragilis NCTC9343 and Bacteroides thetaiotaomicron VPI5482. The putative elements were similar to CTn341 primarily in the tra and mob regions and in the exc gene, and several appeared to contain intron elements. Our data provide the first reported sequence for a complete Bacteroides CTn, and they should be of considerable benefit to further functional and genetic analyses of antibiotic resistance elements and genome evolution in Bacteroides.

Late aortic root dilatation in tetralogy of Fallot may be prevented by early repair in infancy

The objectives of this study were to examine the relative contributions of development and hemodynamics in aortic root dilatation of tetralogy of Fallot, to assess the impact of systemic to pulmonary artery shunt on aortic annular size, and to seek any relationship between the timing of corrective surgery and subsequent aortic root size. We performed a retrospective analytical study at a tertiary referral center of M-mode and two-dimensionol aortic root measurements in children with tetralogy of Fallot prior to any surgical or palliative intervention, after insertion of a surgical shunt, and on intermediate and long-term follow-up post-repair. The main outcome measures were aortic root diameter prior to correction, after palliative shunt insertion, and after definitive repair. The study found that the aortic root is enlarged in unrepaired tetralogy of Fallot irrespective of age, increased in the first 3-6 months after palliative shunt surgery, and persisted into adulthood in those repaired after 1 year of age. Age-corrected aortic root dimensions normalized by mid-childhood in those who were repaired in infancy. Preexisting aortic root dilatation normalizes by 7 years of age in patients with tetralogy of Fallot who have been repaired in infancy, whereas it persists into adulthood in the group repaired post-infancy.

Gastrin releasing peptide (GRP) receptor targeted radiopharmaceuticals: a concise update

The gastrin releasing peptide (GRP) receptor is becoming an increasingly attractive target for development of new radiolabeled peptides with diagnostic and therapeutic potential. The attractiveness of the GRP receptor as a target is based upon the functional expression of GRP receptors in several tumors of neuroendocrine origin including prostate, breast, and small cell lung cancer. This concise review outlines some of the efforts currently underway to develop new GRP receptor specific radiopharmaceuticals by employing a variety of radiometal chelation systems.

Paradoxical reactions during tuberculosis treatment in patients with and without HIV co-infection

BACKGROUND

It has been suggested that deterioration of tuberculosis (TB) during appropriate treatment, termed a paradoxical reaction (PR), is more common and severe in HIV positive individuals on highly active antiretroviral therapy (HAART).

METHOD

A study was undertaken to determine the frequency of PR and its associated features in a population of HIV+TB+ patients and a similar sized group of HIV-TB+ individuals.

RESULTS

PR occurred in 28% of 50 HIV+TB+ patients and 10% of 50 HIV-TB+ patients. Disseminated TB was present in eight of 13 HIV+TB+ patients and four of five HIV-TB+ patients with PR. In 28 HIV+TB+ patients starting HAART, PR was significantly associated with commencing HAART within 6 weeks of starting antituberculosis treatment (p = 0.03) and was more common in those with disseminated TB (p = 0.09). No association was found between development of PR and baseline CD4 count or CD4 response to HAART.

CONCLUSIONS

PR is common in HIV infected and uninfected individuals with TB. Early introduction of HAART and the presence of disseminated TB appear to be important in co-infected patients.

Cardiovascular disease risk factors and antiretroviral therapy in an HIV-positive UK population

AIM

Although the benefits of antiretroviral therapy (ART) have been dramatic, studies have started to report a variety of drug-related side effects and toxicities. We sought to characterize the risk factors for cardiovascular disease present in an HIV-positive population.

METHODS

A total of 394 HIV-positive ambulant patients attending the Royal Free Hospital, London, were asked to complete a questionnaire. Questions focused on smoking habits and general health.

RESULTS

In total, 38% of patients were aged >40 years, 37% had a family history of heart disease, 3% had diabetes, 14% suffered from raised blood pressure, 20% had a body mass index (BMI)>26 kg/m3, 7% had an alcohol consumption above the recommended UK limit, and 18% had total cholesterol levels >6.3 mmol/L [corrected]. The rate of smoking observed (45%) was much higher than that observed amongst the general population in the British Health Survey for England (34%). There were significant differences between those receiving and not receiving ART. Those on ART tended to be younger (P<0.0001) and less likely to smoke cigarettes (P=0.06) or have an alcohol consumption above the recommended limit (P=0.08), but were more likely to have diabetes (P=0.05). More patients receiving ART reported, and so perceived themselves to have, raised blood fats (P<0.0001). This was confirmed when considering blood lipid levels, where those on ART had significantly raised total cholesterol levels compared to those not currently receiving ART (P<0.0001).

CONCLUSION

We have demonstrated an excess of cardiovascular risk factors in this cohort. These issues must be addressed if we wish to maintain the benefit of treating HIV infection.

Linkage analysis for autism in a subset families with obsessive-compulsive behaviors: evidence for an autism susceptibility gene on chromosome 1 and further support for susceptibility genes on chromosome 6 and 19

Although there is considerable evidence for a strong genetic component to idiopathic autism, several genome-wide screens for susceptibility genes have been carried out with limited concordance of linked loci, reflecting numerous genes of weak effect and/or sample heterogeneity. In the current study, linkage analysis was carried out in a sample of 62 autism-affected relative pairs with more severe obsessive-compulsive behaviors, selected from a larger (n=115) set of autism-affected relative pairs as a means of reducing sample heterogeneity. Obsessive-compulsive behaviors were assessed using the Autism Diagnostic Interview-Revised (ADI-R). In the sample with more severe obsessive-compulsive behaviors, multipoint NPL scores above 2 were observed on chromosomes 1, 4, 5, 6, 10, 11 and 19, with the strongest evidence for linkage on chromosome 1 at the marker D1S1656, where the multipoint NPL score was 3.06, and the two-point NPL score was 3.21. In follow-up analyses, analyzing the subset of families (n=35) where the patients had the most severe obsessive-compulsive behaviors generated a multipoint NPL score of 2.76, and a two-point NPL score of 2.79, indicating that the bulk of evidence for linkage was derived from the families most severely affected with obsessive-compulsive behaviors. The data suggest that there is an autism susceptibility gene on chromosome 1 and provide further support for the presence of autism susceptibility genes on chromosomes 6 and 19.

The complex oxidative stress response of Bacteroides fragilis: the role of OxyR in control of gene expression

Gram-negative anaerobes in the genus Bacteroides are the predominant members of the GI-tract microflora where they play an important role in normal intestinal physiology. Bacteroides spp. also are significant opportunistic pathogens responsible for an array of intra-abdominal and other infections. Bacteroides fragilis is the most common anaerobic pathogen and it possesses virulence factors such as a capsule and neuraminidase that contribute to its success as a pathogen. Infection occurs when organisms escape from the anaerobic colon to aerobic sites such as the peritoneum where O(2) concentrations average 6%. Thus in addition to the classic virulence factors, resistance to oxidative stress is essential and may be involved in the initiation and persistence of infection. In fact, B. fragilis is highly O(2) tolerant, surviving extended periods (>24h) of O(2) exposure without a significant affect on viability. For protection against this oxidative stress B. fragilis mounts a complex physiological response that includes induction of >28 proteins involved in detoxification of oxygen radicals, protection of macromolecules, and adaptive physiology. One experimental strategy used to characterize this oxidative stress response is the direct detection of genes and proteins induced during exposure to O(2) or H(2)O(2). The methods employed have included RNA differential display to capture unique mRNA transcripts produced during oxidative stress, and native or 2D-gel electrophoresis to isolate and identify newly formed stress-induced proteins. Using these and other approaches a wide array of genes induced by oxidative stress have been discovered. These include genes for catalase, superoxide dismutase, thioredoxin-peroxidase, p20-peroxidase, cytochrome c peroxidase, Dps, alkyl hydroperoxidase, aerobic ribonucleotide reductase, ruberythrin, starch utilization, aspartate decarboxylase, and an RNA binding protein. The genes encoding these activities fall into three regulatory classes: (1) induced by O(2) only, (2) induced by H(2)O(2) only, and (3) induced by either O(2) or H(2)O(2). Such a complex regulatory response will likely involve multiple regulators. Thus far one regulator has been identified, OxyR, which controls a subset of the class 3 genes that are induced by either O(2) or H(2)O(2). OxyR responds rapidly to oxidative stress and transcriptional analyses have shown that OxyR-controlled genes are activated by as little as 0.5% O(2) or 10 microM H(2)O(2). Maximal expression of most OxyR regulon genes was reached at 50 microM H(2)O(2) and 2% O(2). These oxidant concentrations are similar to environmental levels that would be experienced by the organisms in tissues outside of the colon suggesting that the OxyR regulon would be induced during the course of an infection.

IARC carcinogens reported in cigarette mainstream smoke and their calculated log P values

Cigarette smoke is a complex aerosol of minute liquid droplets (termed the particulate phase) suspended within a mixture of gases (CO(2), CO, NO(x), etc.) and semi-volatile compounds. The International Agency for Research on Cancer (IARC) has classified a number of the chemical constituents reported in cigarette mainstream smoke (MS) as carcinogens. Previously, we published a series of historical reviews reporting that 11 IARC Group 1 (known human), nine Group 2A (probable human) and 48 Group 2B (possible human) carcinogens have been observed in MS. Here, we expand the list of IARC classified carcinogens from 68 to 81 compounds (11 Group 1, 14 Group 2A and 56 Group 2B) reported in MS. A number of the IARC compounds reported in MS are found in the vapor phase including three Group 1, eight Group 2A and 18 Group 2B constituents. Several IARC MS compounds are found in both the vapor and particulate phases including two in Group 1, one in Group 2A and one in Group 2B. Forty-eight IARC MS carcinogens are found in the particulate phase only. Lipophilicity, as determined by the base 10 logarithm of the calculated octanol-water partition coefficient and denoted as Clog P, is reported for each of the 71 non-metallic MS IARC carcinogens. Clog P correlates with a number of biological activities including in vitro mutagenicity and carcinogenicity in rodents, and in the absence of any additional toxicological or epidemiological data, a high log P compound is more likely to be carcinogenic than a low log P compound.