Suppression of plasma viral load below 20 copies/ml is required to achieve a long-term response to therapy

BACKGROUND

Current guidelines state that the goal of antiretroviral therapy for HIV-infected individuals is to suppress plasma viral load (pVL) to below 400 copies/ml.

METHODS

Predictors of achieving and maintaining pVL suppression were examined in a randomized trial of combinations of zidovudine, nevirapine and didanosine in patients with CD4+ T cell counts of between 200 and 600 x 10(6) cells/l who were naive to antiretroviral therapy and AIDS-free at enrolment.

RESULTS

One hundred and four patients had pVL > 500 copies/ml at baseline and a pVL nadir below 500 copies/ml. Of these, 77 patients experienced an increase in pVL above 500 copies/ml. The median number of days of pVL suppression to below 500 copies/ml was 285 (42) for patients with pVL nadir < or = (>) 20 copies/ml (P = 00.0001). The relative risk of an increase in pVL above 500 copies/ml associated with a pVL nadir below 20 copies/ml was 0.11 (P = 0.0001). The relative risks of an increase in pVL above 5000 copies/ml associated with a pVL nadir below 20 copies/ml or between 20 and 400 copies/ml were 0.05 [95% confidence interval (CI), 0.02-0.12] and 0.37 (95% CI, 0.23-0.61) respectively, compared with individuals with a pVL nadir > 400 copies/ml. Individuals with a pVL nadir < or = 20 copies/ml were at a significantly lower risk of virologic failure than individuals with a pVL nadir of between 21 and 400 copies/ml (P = 0.0001).

CONCLUSIONS

Our results demonstrate that suppression of pVL below 20 copies/ml is necessary to achieve a long-term antiretroviral response. Our data support the need for a revision of current therapeutic guidelines for the management of HIV infection.

Maternal cigarette smoking is associated with increased inner airway wall thickness in children who die from sudden infant death syndrome

The harmful effects of passive cigarette smoke exposure to infants include an increased frequency of asthma exacerbations, lower respiratory viral infections, and the sudden infant death syndrome (SIDS). Because of a difficulty in obtaining airway tissue from infants, little information is available on the effects of passive cigarette smoke exposure on the structure of the infant airway wall. We examined airway dimensions in 19 children who died from SIDS whose mothers smoked more than 20 cigarettes a day prenatally and postnatally, and compared these data with those from 19 infants who died from SIDS and had nonsmoking mothers. Total inner and outer wall areas were calculated for each airway and expressed in terms of the basement membrane perimeter (Pbm). Inner airway wall thickness was greater in the larger airways of those infants whose mothers had smoked more than 20 cigarettes a day. These findings suggest that infants exposed to a high level of passive cigarette smoke develop significant structural changes in their airways. Increased airway wall thickness may contribute to exaggerated airway narrowing and may help explain the previously observed abnormalities in neonatal lung function that have been described in infants of smoking mothers.

Precision and reliability for measurement of change in MRI lesion volume in multiple sclerosis: a comparison of two computer assisted techniques

OBJECTIVE

The serial quantification of MRI lesion load in multiple sclerosis provides an effective tool for monitoring disease progression and this has led to its increasing use as an outcome measure in treatment trials. Segmentation techniques must display a high degree of precision and reliability if they are to be responsive to small changes over time. This study has evaluated the performance of two such techniques, the manual outlining and contour methods, in serial lesion load quantification.

METHODS

Sixteen patients with clinically definite multiple sclerosis were scanned at baseline and after two years. Scan analysis was performed twice, independently by three observers using each technique.

RESULTS

For the absolute lesion volumes the median intrarater coefficient of variation (CV) was 3.2% for the contour technique and 7.6% for the manual outlining method (p < 0.005), the interrater CVs were 3.8% and 6.1% respectively (p < 0.01) and the reliability of both techniques was very high. For the change in lesion volume the intrarater and interrater repeatability coefficients were respectively 2.6 cm3 and 2.8 cm3 for the contour technique, and 3.3 cm3 and 3.7 cm3 for the manual outlining method (lower values reflect higher precision). The values for intrarater and interrater reliability for measuring change in lesion volume were respectively, 0.945 and 0.944 for the contour technique, and 0.939 and 0.921 for the manual outline method (perfect reliability = 1.0).

CONCLUSIONS

With such high values for reliability, the impact of measurement error in lesion segmentation on sample size requirements in multiple sclerosis treatment trials is minor. This study shows that a change in lesion volume can be measured with a higher level of precision and reliability with the contour technique and this supports its further application in serial studies.

Impact of improved depression treatment in primary care on daily functioning and disability

BACKGROUND

Few data are available regarding the impact of improved depression treatment on daily functioning and disability.

METHODS

In two studies of more intensive depression treatment in primary care, patients initiating antidepressant treatment were randomly assigned to either usual care or to a collaborative management programme including patient education, on-site mental health treatment, adjustment of antidepressant medication, behavioural activation and monitoring of medication adherence. Assessments at baseline as well as 4 and 7 months included several measures of impairment, daily functioning and disability: self-rated overall health, number of bodily pains, number of somatization symptoms, changes in work due to health, reduction in leisure activities due to health, number of disability days and number of restricted activity days.

RESULTS

Average data from the 4- and 7-month assessments in both studies, intervention patients reported fewer somatic symptoms (OR 0.68, 95% CI 0.46, 0.99) and more favourable overall health (OR 0.50, 95% CI 0.28, 0.91). While intervention patients fared better on other measures of functional impairment and disability, none of these differences reached statistical significance.

CONCLUSIONS

More effective acute-phase depression treatment reduced somatic distress and improved self-rated overall health. The absence of a significant intervention effect on other disability measures may reflect the brief treatment and follow-up period and the influence of other individual and environmental factors on disability.

Executive function in treated phenylketonuria as measured by the one-back and two-back versions of the continuous performance test

The executive dysfunction hypothesis in treated phenylketonuria was investigated by means of the one-back and two-back versions of the continuous performance test. Eleven non-retarded, primary school-age children with classical phenylketonuria who had been treated early and continuously were indistinguishable from healthy, matched controls on the measures and test performance was not predicted by historical or concurrent plasma phenylalanine concentrations. Mean lifetime phenylalanine concentrations for the phenylketonuric subjects were within ranges currently recommended as dietary optima in the United Kingdom. The negative neuropsychological test findings add weight to the rationale for this policy.

A randomized, double-blind trial comparing combinations of nevirapine, didanosine, and zidovudine for HIV-infected patients: the INCAS Trial. Italy, The Netherlands, Canada and Australia Study

CONTEXT

Current guidelines recommend that individuals infected with the human immunodeficiency virus type 1 (HIV-1) be treated using combinations of antiretroviral agents to achieve sustained suppression of viral replication as measured by the plasma HIV-1 RNA assay, in the hopes of achieving prolonged remission of the disease. However, until recently, many drug combinations have not led to sustained suppression of HIV-1 RNA.

OBJECTIVE

To compare the virologic effects of various combinations of nevirapine, didanosine, and zidovudine.

DESIGN

Double-blind, controlled, randomized trial.

SETTING

University-affiliated ambulatory research clinics in Italy, the Netherlands, Canada and Australia (INCAS).

PATIENTS

Antiretroviral therapy-naive adults free of the acquired immunodeficiency syndrome with CD4 cell counts between 0.20 and 0.60x10(9)/L (200-600/microL).

INTERVENTION

Patients received zidovudine plus nevirapine (plus didanosine placebo), zidovudine plus didanosine (plus nevirapine placebo), or zidovudine plus didanosine plus nevirapine.

MAIN OUTCOME MEASURE

Plasma HIV-1 RNA.

RESULTS

Of the 153 enrolled patients, 151 were evaluable. At week 8, plasma HIV-1 RNA levels had decreased by log 2.18, 1.55, and 0.90 in the triple drug therapy, zidovudine plus didanosine, and zidovudine plus nevirapine groups, respectively (P<.05). The proportions of patients with plasma HIV-1 RNA levels below 20 copies per milliliter at week 52 were 51%, 12%, and 0% in the triple drug therapy, zidovudine plus didanosine, and zidovudine plus nevirapine groups, respectively (P<.001). Viral amplification was attempted in 59 patients at 6 months. Viral isolation was unsuccessful in 19 (79%) of 24, 10 (53%) of 19, and 5 (31%) of 16 patients in the triple drug therapy, zidovudine plus didanosine, and zidovudine plus nevirapine groups, respectively. Among patients from whom virus could be amplified, resistance to nevirapine was found in all 11 patients receiving zidovudine plus nevirapine and in all 5 patients receiving triple drug therapy. Rates of disease progression or death were 23% (11/47), 25% (13/53), and 12% (6/51) for the zidovudine plus nevirapine, zidovudine plus didanosine, and triple drug therapy groups, respectively (P=.08).

CONCLUSIONS

Triple drug therapy with zidovudine, didanosine, and nevirapine led to a substantially greater and sustained decrease in plasma viral load than the 2-drug regimens studied. Our results also suggest that suppression of viral replication, as demonstrated by a decrease in the plasma HIV-1 RNA load below the level of quantitation of the most sensitive test available, may at least forestall the development of resistance.

Health effects of exposure to cyanobacteria (blue-green algae) during recreational water-related activities

The aim of this study was to investigate effects on health of exposure to cyanobacteria as a result of recreational water activities. Participants, who were aged six years and over, were interviewed at water recreation sites in South Australia, New South Wales and Victoria on selected Sundays during January and February 1995. Telephone follow-up was conducted two and seven days later to record any subsequent diarrhoea, vomiting, flu-like symptoms, skin rashes, mouth ulcers, fevers and eye or ear irritations. On the Sundays of interview, water samples from the sites were collected for cyanobacterial cell counts and toxin analysis. There were 852 participants, of whom 75 did not have water contact on the day of interview and were considered unexposed. The 777 who had water contact were considered exposed. No significant differences in overall symptoms were found between the unexposed and exposed after two days. At seven days, there was a significant trend to increasing symptom occurrence with duration of exposure (P = 0.03). There was a significant trend to increasing symptom occurrence with increase in cell count (P = 0.04). Participants exposed to more than 5000 cells per mL for more than one hour had a significantly higher symptom occurrence rate than the unexposed. Symptoms were not correlated with the presence of hepatotoxins. These results suggest symptom occurrence was associated with duration of contact with water containing cyanobacteria, and with cyanobacterial cell density. The findings suggest that the current safety threshold for exposure of 20,000 cells per mL may be too high.

Preparing kids for the new baby

Sibling prenatal classes are a natural extension of nursing's interest and expertise in childbirth preparation for expectant couples. From parents' perspective, these classes have the potential to decrease sibling rivalry and facilitate parental coping with older children's concerns about a new baby. From a nurse educator's perspective, sibling prenatal classes offer a rich learning experience for students by providing an opportunity to integrate knowledge about pregnancy and birth with communication skills and child development knowledge.

The polymerase chain reaction: from functional genomics to high-school practical classes

After a decade of intensive use as an in vitro alternative to cloning DNA, PCR is now well established as the default method for DNA and RNA analysis. Recent developments have consolidated this position by the introduction of more robust formats, improvements in thermal cyclers and labelling and detection methods. The trend is towards increasing automation, although comparatively few diagnostic kits based on PCR are in wide use. At the same time the applications of PCR are being extended with modifications such as long, accurate PCR and arrayed oligonucleotides or expressed sequences.

ATM mutations and phenotypes in ataxia-telangiectasia families in the British Isles: expression of mutant ATM and the risk of leukemia, lymphoma, and breast cancer

We report the spectrum of 59 ATM mutations observed in ataxia-telangiectasia (A-T) patients in the British Isles. Of 51 ATM mutations identified in families native to the British Isles, 11 were founder mutations, and 2 of these 11 conferred a milder clinical phenotype with respect to both cerebellar degeneration and cellular features. We report, in two A-T families, an ATM mutation (7271T-->G) that may be associated with an increased risk of breast cancer in both homozygotes and heterozygotes (relative risk 12.7; P=. 0025), although there is a less severe A-T phenotype in terms of the degree of cerebellar degeneration. This mutation (7271T-->G) also allows expression of full-length ATM protein at a level comparable with that in unaffected individuals. In addition, we have studied 18 A-T patients, in 15 families, who developed leukemia, lymphoma, preleukemic T-cell proliferation, or Hodgkin lymphoma, mostly in childhood. A wide variety of ATM mutation types, including missense mutations and in-frame deletions, were seen in these patients. We also show that 25% of all A-T patients carried in-frame deletions or missense mutations, many of which were also associated with expression of mutant ATM protein.

A 2-alkyl substituted 2,3,1-benzodiazaborine

The structure of the fourth member of a family of structurally related 2,3,1-benzodiheteroborines has been solved by crystallographic means, providing data for proper direct comparison with the others. The title compound, 1,2-dihydro-1-hydroxy-2-methyl-2,3,1-benzodiazaborine (C8H9BN2O) is obtained via condensation of 2-formylbenzeneboronic acid and methylhydrazine, and is similar in most respects to its 2-unsubstituted parent, in internal geometry and intramolecular association topography, but has some subtle oxazaborine-like characteristics.

Sharps injuries in dental practice

Sharps injuries are common in dental practice and may allow transmission of blood-borne viruses. The transmission rates of hepatitis B (HBV) to non-vaccinated recipients, hepatitis C (HCV) and human immunodeficiency virus (HIV) after a needlestick injury are 6-30%, 2.7-10% and 0.1-0.3% respectively. Five strategies to prevent percutaneous injuries in dental surgeries are considered: a universal level of infection-control, surgery design, working practices, glove use and vaccinations. First-aid for sharps injuries and post-exposure management of those involving sources with HBV and HIV are described. Anticipation, planning and training can reduce the incidence of injuries and minimise their impact.

Early high dose chemotherapy intensification with autologous bone marrow transplantation in lymphoma associated with retention of fertility and normal pregnancies in females. Scotland and Newcastle Lymphoma Group, UK

As more centres consider autologous bone marrow and peripheral blood stem cell transplantation for patients with high risk Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) in first complete remission (CR1) the long term sequelae of such treatments have to be considered. One of the most important side effects of such intensive treatment is loss of fertility. Sperm banking before treatment commences is available for males but unfortunately cryopreservation of ova/ovarian tissue is not yet possible for females. We have transplanted 30 women, 23 were under 40 years and report ten females who have had successful pregnancies (including two twin pregnancies and one triplet pregnancy), leading to live births following autologous bone marrow transplantation (ABMT) for poor prognosis HD and NHL in first or second complete remission. None of these children have shown evidence of birth defects (median follow up of two years). Of the twenty one pregnancies reported to the European Bone Marrow Transplantation Registry (EBMTR) following ABMT for lymphoma, eight of the seventeen unassisted cases came from our centres. The Newcastle/SNLG autotransplant differs from the approach in many EBMTR centres in that it uses melphalan or melphalan/etoposide alone instead of the more common four drug containing regimens and yet sustained complete remission rates indicate that the non-ablative approach is equally effective as more aggressive regimens on the disease with the huge advantage of preserved fertility in females. This approach to conditioning for ABMT should be considered when treating women in the reproductive age group.

Determination of manipulative physiotherapy treatment outcome in headache patients

SUMMARY. Although physiotherapists are frequently involved in the treatment of headache when cervical spine dysfunction is thought to be a cause or contributing factor there does not appear to be a consistent definition of treatment success. This study analysed treatment outcome in a population of 112 headache patients presenting for manipulative physiotherapy. Two months after the initial consultation, statistically significant improvements were observed in mean scores for each of headache frequency (P < 0.001), duration (P < 0.05) and intensity (P < 0.001). When a combination of patient estimate of treatment effect and a headache index incorporating scores for frequency, intensity and duration was used to classify treatment outcome, 51 of the 91 subjects analysed at follow-up were deemed to have had a positive response to treatment. This method of classification of treatment outcome appeared to be sensitive to cases where the patient's headaches were improved by factors other than the physiotherapy treatment. However the classification used was less sensitive when the patient's headaches were aggravated by other factors or where there was not consistent improvement or deterioration in the measures of headache frequency, intensity and duration. Copyright 1997 Harcourt Publishers Ltd.

Paediatric slow-speed non-traffic fatalities: Victoria, Australia, 1985-1995

An important group of fatal incidents are slow-speed pedestrian non-traffic incidents to children, which account for 14% of accidental deaths from all causes in Victorian children under 5 years of age between 1985 and 1995, and 12% of pedestrian deaths of all ages. In Victoria, Australia, the database of the state Consultative Council on Obstetric and Paediatric Morbidity and Mortality was utilised to identify paediatric slow-speed pedestrian non-traffic-accident deaths in the local population. Additional data relating to the car and its driver, the child, and the circumstances of the incident were abstracted from records kept by the State Coroner and the Victorian compulsory third party traffic injury insurance organisation. Twenty eight Victorian children were identified who had died in one of three types of incident (driverless cars, child interacting with the vehicle and driver, and drivers who were unaware of the child's proximity). These incidents were more common in rural areas compared with urban, usually occurring at the child's home. The child was with or near an adult on all occasions. The vehicle was usually being driven by a relative, and was reversing in a higher proportion of 'unaware' incidents compared with the 'interactive' type. The association of 'off-road' family vehicles and trucks with these incidents appears to be increasing, especially in recent years. These findings suggest some countermeasures, including the separation of vehicle driveways from children's play areas, and object vicinity ultrasonic warning devices for vehicles.