Fetal and early life growth and body mass index from birth to early adulthood in 1958 British cohort: longitudinal study

OBJECTIVES

To determine the influence of birth weight on body mass index at different stages of later life; whether this relation persists after accounting for potential confounding factors; and the role of indicators of fetal growth (birth weight relative to parental size) and childhood growth.

DESIGN

Longitudinal study of the 1958 British birth cohort.

SETTING

England, Scotland, and Wales.

PARTICIPANTS

All singletons born 3-9 March 1958 (10 683 participants with data available at age 33).

MAIN OUTCOME MEASURES

Body mass index at ages 7, 11, 16, 23, and 33 years.

RESULTS

The relation between birth weight and body mass index was positive and weak, becoming more J shaped with increasing age. When adjustments were made for maternal weight, there was no relation between birth weight and body mass index at age 33. Indicators of poor fetal growth based on the mother's body size were not predictive, but the risk of adult obesity was higher among participants who had grown to a greater proportion of their eventual adult height by age 7. In men only, the effect of childhood growth was strongest in those with lower birth weights and, to a lesser extent, those born to lighter mothers.

CONCLUSIONS

Maternal weight (or body mass index) largely explains the association between birth weight and adult body mass index, and it may be a more important risk factor for obesity in the child than birth weight. Birth weight and maternal weight seem to modify the effect of childhood linear growth on adult obesity in men. Intergenerational associations between the mother's and her offspring's body mass index seem to underlie the well documented association between birth weight and body mass index. Other measures of fetal growth are needed for a fuller understanding of the role of the intrauterine environment in the development of obesity.

Using an interactive framework of society and lifecourse to explain self-rated health in early adulthood

This paper presents an integrated model of the determinants of adult health combining lifecourse factors and contemporary circumstances. Using the 1958 British Birth Cohort, it operationalises lifecourse influences in terms of factors from birth to age 33, which might act through latent, pathway, or cumulative effects. Contemporary circumstances are represented by variables at different levels of social aggregation: macro (socio-economic circumstances); meso (involvement in civil society functions); micro (personal social support); and intersecting (job insecurity and life control). Multiple regression models were fitted, using self-rated health at age 33 as the health outcome. To allow for temporal ordering of events, early life factors were entered first in the final model, followed by later childhood factors and, finally current factors. Self-rated health was predicted by variables representing both early and later stage of the lifecourse and also contemporary societal-level factors. The effects of childhood factors were not removed by including contemporary factors, and conversely, contemporary factors contributed to the prediction of self-rated health over and above lifecourse factors. The factors were not collinear; supporting the notion that each dimension was distinct from the others. Although the model accounted for only 9% of the variance in self-rated health, the general conclusion is that both lifecourse and contemporary circumstances should be considered together in explaining adult health.

Bacterial wall products induce downregulation of vascular endothelial growth factor receptors on endothelial cells via a CD14-dependent mechanism: implications for surgical wound healing

INTRODUCTION

Vascular endothelial growth factor (VEGF) is a potent mitogenic cytokine which has been identified as the principal polypeptide growth factor influencing endothelial cell (EC) migration and proliferation. Ordered progression of these two processes is an absolute prerequisite for initiating and maintaining the proliferative phase of wound healing. The response of ECs to circulating VEGF is determined by, and directly proportional to, the functional expression of VEGF receptors (KDR/Flt-1) on the EC surface membrane. Systemic sepsis and wound contamination due to bacterial infection are associated with significant retardation of the proliferative phase of wound repair. The effects of the Gram-negative bacterial wall components lipopolysaccharide (LPS) and bacterial lipoprotein (BLP) on VEGF receptor function and expression are unknown and may represent an important biological mechanism predisposing to delayed wound healing in the presence of localized or systemic sepsis.

MATERIALS AND METHODS

We designed a series of in vitro experiments investigating this phenomenon and its potential implications for infective wound repair. VEGF receptor density on ECs in the presence of LPS and BLP was assessed using flow cytometry. These parameters were assessed in hypoxic conditions as well as in normoxia. The contribution of CD14 was evaluated using recombinant human (rh) CD14. EC proliferation in response to VEGF was quantified in the presence and absence of LPS and BLP.

RESULTS

Flow cytometric analysis revealed that LPS and BLP have profoundly repressive effects on VEGF receptor density in normoxic and, more pertinently, hypoxic conditions. The observed downregulation of constitutive and inducible VEGF receptor expression on ECs was not due to any directly cytotoxic effect of LPS and BLP on ECs, as measured by cell viability and apoptosis assays. We identified a pivotal role for soluble/serum CD14, a highly specific bacterial wall product receptor, in mediating these effects. The decreased VEGF receptor density on ECs accruing from the presence of bacterial wall products resulted in EC hyporesponsiveness to rhVEGF and significant abolition of VEGF-directed EC proliferation.

CONCLUSION

These findings suggest that the well-recognized relationship between bacterial sepsis and attenuated wound healing may be due, in part, to the directly suppressive effects of bacterial wall components on EC VEGF receptor expression and, consequently, EC proliferation.

Matrix metalloproteinase activity inactivates the CXC chemokine stromal cell-derived factor-1

Chemokines provide directional cues for leukocyte migration and activation that are essential for normal leukocytic trafficking and for host responses during processes such as inflammation, infection, and cancer. Recently we reported that matrix metalloproteinases (MMPs) modulate the activity of the CC chemokine monocyte chemoattractant protein-3 by selective proteolysis to release the N-terminal tetrapeptide. Here we report the N-terminal processing, also at position 4-5, of the CXC chemokines stromal cell-derived factor (SDF)-1alpha and beta by MMP-2 (gelatinase A). Robustness of the MMP family for chemokine cleavage was revealed from identical cleavage site specificity of MMPs 1, 3, 9, 13, and 14 (MT1-MMP) toward SDF-1; selectivity was indicated by absence of cleavage by MMPs 7 and 8. Efficient cleavage of SDF-1alpha by MMP-2 is the result of a strong interaction with the MMP hemopexin C domain at an exosite that overlaps the monocyte chemoattractant protein-3 binding site. The association of SDF-1alpha with different glycosaminoglycans did not inhibit cleavage. MMP cleavage of SDF-1alpha resulted in loss of binding to its cognate receptor CXCR-4. This was reflected in a loss of chemoattractant activity for CD34(+) hematopoietic progenitor stem cells and pre-B cells, and unlike full-length SDF-1alpha, the MMP-cleaved chemokine was unable to block CXCR-4-dependent human immunodeficiency virus-1 infection of CD4(+) cells. These data suggest that MMPs may be important regulatory proteases in attenuating SDF-1 function and point to a deep convergence of two important networks, chemokines and MMPs, to regulate leukocytic activity in vivo.

Predictors of low back pain onset in a prospective British study

OBJECTIVES

This study examined predictors of low back pain onset in a British birth cohort.

METHODS

Univariate and multivariate analyses focused on individuals who experienced onset of low back pain at 32 to 33 years of age (n= 571) and individuals who were pain free (n = 5210). Participants were members of the 1958 British birth cohort.

RESULTS

Incident pain was elevated among those with psychological distress at 23 years of age (adjusted odds ratio [OR] = 2.52, 95% confidence interval [CI] = 1.65, 3.86) and among persistent moderate or heavy smokers (adjusted OR = 1.63, 95% CI = 1.23, 2.17). Significant univariate associations involving other factors (e.g., social class, childhood emotional status, body mass index, job satisfaction) did not persist in multivariate analyses.

CONCLUSIONS

This prospectively studied cohort provides evidence that psychological distress more than doubles later risk of low back pain, with smoking having a modest independent effect. Other prospective studies are needed to confirm these findings before implications for low back pain prevention can be assessed.

Monocyte activation and differentiation augment human endogenous retrovirus expression: implications for inflammatory brain diseases

Human endogenous retroviruses (HERVs) have been implicated as causative agents in diseases characterized by inflammation and macrophage activation, such as multiple sclerosis. Because monocyte activation and differentiation influence retroviral transcription and replication, we investigated the contribution of these processes to the expression of four HERV families (HERV-W, HERV-K, HERV-E, and HERV-H) in human monocytes, and autopsied brain tissue from patients with brain diseases associated with increased macrophage activity. Reverse transcriptase-polymerase chain reaction analysis of primary macrophages and U937 monocytoid cells stimulated with phorbol-12-myristate-13-acetate or lipopolysaccharide revealed three- to ninefold increases in HERV-W, HERV-K, and HERV-H RNA levels. In addition, elevated reverse transcriptase activity and HERV RNA were detectable in supernatants from PMA-stimulated U937 cultures, properties that could be attenuated with the inhibitor of monocyte differentiation threonine-lysine-proline. In contrast, stimulation of monocytes decreased or had no effect on HERV-E expression. Compared with controls, HERV-W and HERV-K expression was increased in brain tissue from patients with multiple sclerosis or human immunodeficiency virus infection or AIDS, with concomitant elevated tumor necrosis factor-alpha levels. Similarly, elevated HERV-W levels were detected in patients with Alzheimer's dementia only when tumor necrosis factor-alpha expression was also evident (2 of 6 cases). The detection of several HERVs in inflammatory brain diseases and the capacity to augment HERV expression in monocytes with compounds that influence cellular activity suggest that increased expression of these viruses is a consequence of increased immune activity rather than causative of distinct diseases.

A case for a neonatal, low-dose BCG vaccination trial

The rational design of a successful vaccination strategy against tuberculosis requires certain kinds of information and must take account of several considerations: (i) the nature of the immune response that protects the large majority of individuals infected by Mycobacterium tuberculosis, designated as healthy contacts, must be defined and distinguished from that in tuberculosis patients, whose immune system must have failed; (ii) the vaccination strategy must incorporate a way of priming the immune system to guarantee in all individuals this protective response, normally generated in healthy contacts, upon natural infection by M. tuberculosis; (iii) the strategy must incorporate a mechanism for ensuring that the effectiveness of this priming is not abrogated by exposure to environmental mycobacteria; and (iv) the strategy must take account of the fact that the vaccinated population is genetically heterogeneous, and that individuals will therefore respond variably to most standard vaccination protocols. We describe a tentative proposal for how these interrelated problems might be solved and discuss predictions of this tentative vaccination strategy. Critical testing of the neonatal, low-dose BCG vaccination strategy can only be achieved by a field trial and we outline the considerations underlying this proposal.

Family social class, maternal body mass index, childhood body mass index, and age at menarche as predictors of adult obesity

BACKGROUND

Obesity is an increasingly prevalent nutritional disorder throughout the world and is a risk factor for many chronic diseases. The prevalence of obesity increases with age.

OBJECTIVE

The objective was to evaluate the associations between BMI at 31 y of age and family social class during early childhood, maternal body mass index (BMI) before pregnancy, BMI at birth and at 1 and 14 y of age, and age at menarche.

DESIGN

This was a longitudinal study of the northern Finland birth cohort for 1966. Subjects were measured at birth and at 1, 14, and 31 y of age. The analysis was restricted to individuals for whom BMI data were available for all measurement points (n = 2876 males and 3404 females).

RESULTS

The mean BMI at birth was highest in offspring from the highest social classes, but BMI was inversely related to social class at 1 y. BMI, the waist-to-hip ratio, and the proportion of obese subjects were inversely related to social class at 31 y. The heavier the mother, the heavier the offspring from birth to 31 y. The paired analyses between maternal BMI and daughter's BMI at 31 y showed no significant difference in BMI after adjustment for the age difference. BMI at 14 y was the most important predictor of BMI at 31 y. Early menarche in females was associated with a higher BMI at 14 and 31 y.

CONCLUSIONS

Differences in BMI by social class are formed at least partly during early childhood. Low social class of the child's family, a high maternal BMI before pregnancy, a high BMI during adolescence, and early menarche are predictors of obesity in adulthood.

Encephalopathy with staphylococcal endocarditis: multiple neuropathological findings

BACKGROUND

Infective endocarditis is associated with serious neurological sequelae.

OBJECTIVE

Here, we report a patient with Staphylococcus aureus endocarditis, secondary to congenital heart disease, with subacute onset of multiple neurological complications.

RESULTS

Despite prompt antibiotic treatment with rapid sterilization of blood cultures, the patient died with brain herniation within 96 hours of admission. Neuropathological examination showed intraparenchymal hemorrhages, mycotic aneurysms, micro-abscesses and septic arteritis with accompanying infarction. Immunocytochemical studies revealed enhanced CD45 and GFAP immunoreactivity, together with adenosine A1 receptor detection on macrophages and microglia.

CONCLUSIONS

Infective endocarditis is associated with multiple neuropathological lesions, which may contribute to its poor clinical outcome and activation of cells of monocyte-microglial lineage throughout the brain.

Neurocognitive symptoms and impairment in an HIV community clinic

BACKGROUND

Neurocognitive impairment is a frequent complication of HIV infection and heralds a poor survival prognosis. With the availability of highly active antiretroviral therapy (HAART), survival times for HIV-infected patients have markedly increased although the effects of HAART on the prevalence of neurocognitive impairment remain uncertain.

OBJECTIVE

To determine the relationship between self-reported neurocognitive symptoms and neuropsychological (NP) performance together with the impact of HAART among HIV-infected patients.

METHODS

A cross-sectional study was performed in which patients without previously documented neurocognitive impairment attending an HIV community clinic were questioned about neurocognitive symptoms and a NP test battery was administered.

RESULTS

Of the eighty-three patients examined, neurocognitive symptoms were reported by 34% of patients and were associated with a shorter duration of HAART and higher viral loads. Patients reporting neurocognitive symptoms were also more likely to exhibit impaired NP performance (p<0.005) with NP impairment being detected in 46% of all patients examined (12% with HIV-associated dementia). Neuropsychological impairment was directly correlated with age (p<0.001), plasma viral load (p<0.005) and inversely correlated with the number of prescribed antiretroviral drugs (p<0.01).

CONCLUSIONS

These results suggest that neurocognitive symptoms are predictive of impaired NP performance and that NP impairment remains a frequent finding among older patients with higher viral loads. An increased number of antiretroviral drugs may be neuroprotective.

Xenoinfection of nonhuman primates by feline immunodeficiency virus

New viral infections in humans usually result from viruses that have been transmitted from other species as zoonoses. For example, it is accepted widely that human immunodeficiency virus (HIV) is the result of the propagation and adaptation of a simian immunodeficiency virus (SIV) from nonhuman primates to man [1]. Previously, we reported productive infection of primary human cells in vitro by feline immunodeficiency virus (FIV) [2], a lentivirus that causes an immunodeficiency syndrome in cats similar to HIV in humans [3]. The present study extends these findings by demonstrating that cynomolgus macaques (Macaca fasicularis) infected with FIV exhibited clinical signs, including depletion of CD4+ cells and weight loss, that are consistent with FIV infection. The development of an antibody response to FIV gag-encoded proteins and detection of virus-specific sequences in sera, blood-derived cells, and necropsied tissue accompanied these changes. Moreover, the reactivation of FIV replication from latently infected cells was observed after stimulation in vitro with phorbol esters and in vivo with tetanus toxoid. The proposed use of lentiviruses in human gene therapy [4, 5] and of nonhuman cells and organs in xenotransplantation [6] has raised concerns about zoonoses as potential sources of new human pathogens. Therefore, the study of FIV infection of primate cells may provide insight into the principles underlying retroviral xenoinfections.

Genetic susceptibility to MS: a second stage analysis in Canadian MS families

Four published genome screens have identified a number of markers with increased sharing in multiple sclerosis (MS) families, although none has reached statistical significance. One hundred and five markers previously identified as showing increased sharing in Canadian, British, Finnish, and American genome screens were genotyped in 219 sibling pairs ascertained from the database of the Canadian Collaborative Project on Genetic Susceptibility to MS (CCPGSMS). No markers examined met criteria for significant linkage. Markers located at 5p14 and 17q22 were analyzed in a total of 333 sibling pairs and attained mlod scores of 2.27 and 1.14, respectively. The known HLA Class II DRB1 association with MS was confirmed (P<0.0001). Significant transmission disequilibrium was also observed for D17S789 at 17q22 (P=0.0015). This study highlights the difficulty of searching for genes with only mild-to-moderate effects on susceptibility, although large effects of specific loci may still be present in individual families. Future progress in the genetics of this complex trait may be helped by (1) focussing on more ethnically homogeneous samples, (2) using an increased number of MS families, and (3) using transmission disequilibrium analysis in candidate regions rather than the affected relative pair linkage analysis.

Metalloproteinases in biology and pathology of the nervous system

Matrix metalloproteinases (MMPs) and ADAMs (a disintegrin and metalloproteinase) are part of a larger family of structurally related zinc-dependent metalloproteinases called metzincins. Structurally, MMPs are divided in three domains: an amino-terminal propeptide region, an amino-terminal catalytic domain, and a carboxy-terminal domain that is involved in substrate binding. ADAMs have a prodomain, a metalloprotease region, a disintegrin domain for adhesion, a cysteine-rich region, epidermal-growth-factor repeats, a transmembrane module and a cytoplasmic tail. The activity of MMPs is tightly regulated in several ways: at the level of transcription, by post-translational modifications such as proteolysis, and through the action of endogenous tissue inhibitors of metalloproteinases. The regulation of ADAMs is less well understood, although there is some evidence that the same three levels of regulation might control ADAM activity. MMPs and ADAMs have been implicated in neuroinflammation and multiple sclerosis (MS), in the pathogenesis of malignant gliomas, and in other neurological conditions such as stroke, viral infections and Alzheimer's disease. In the case of ADAMs, their role in these pathological states has begun to be explored, but the available literature is still in its infancy. Although the detrimental roles of metalloproteinases are well documented, some of their functions in the central nervous system (CNS) might be beneficial. For example, some metalloproteinases are expressed in the CNS during development, pointing to a possible role in brain maturation. Similarly, metalloproteinases have been implicated in myelinogenesis and axon growth. Furthermore, metalloproteinases are upregulated after injury to the CNS, indicating a possible relevance to tissue repair. Several challenges remain in the study of metalloproteinases and their role in brain function. It will be necessary to understand the balance between the beneficial and detrimental roles of MMPs to determine whether they can be used as targets for therapeutic intervention. It will also be important to identify the physiological substrates of the different metalloproteinases, and to develop selective antagonists against the various members of the metalloproteinase families; the lack of such tools constitutes one of the main limitations to the growth of the field at present.

Matrix metalloproteinases (MMPs) have been implicated in several diseases of the nervous system. Here we review the evidence that supports this idea and discuss the possible mechanisms of MMP action. We then consider some of the beneficial functions of MMPs during neural development and speculate on their roles in repair after brain injury. We also introduce a family of proteins known as ADAMs (a disintegrin and metalloproteinase), as some of the properties previously ascribed to MMPs are possibly the result of ADAM activity.

Proinflammatory effects of bacterial lipoprotein on human neutrophil activation status, function and cytotoxic potential in vitro

Bacterial lipoprotein (BLP) is the most abundant protein in gram-negative bacterial cell walls, heavily outweighing lipopolysaccharide (LPS). Herein we present findings demonstrating the potent in vitro effects of BLP on neutrophil (PMN) activation status, function, and capacity to transmigrate an endothelial monolayer. PMNs are the principal effectors of the initial host response to injury or infection and constitute a significant threat to invading bacterial pathogens. The systemic inflammatory response syndrome (SIRS) is characterised by significant host tissue injury mediated, in part, by uncontrolled regulation of PMN cytotoxic activity. We found that BLP-activated human PMN as evidenced by increased CD11b/CD18 (Mac-1) expression. Up-regulation of PMN Mac-1 in response to BLP occurred independently of membrane-bound CD14 (mCD14). A similar up-regulation of intercellular adhesion molecule-1 (ICAM-1) on endothelial cells was observed whilst E-Selectin expression was unaffected. PMN transmigration across a human umbilical vein endothelial cell (HUVEC) monolayer was markedly increased after treating either PMN's or HUVEC independently with BLP. This increased transmigration did not occur as a result of any direct effect of BLP on HUVEC monolayer permeability, assessed objectively using the passage of FITC-labeled Dextran-70. BLP primed PMN for enhanced respiratory burst and superoxide anion production in response to PMA, but did not influence phagocytosis of opsonized Escherichia coli. BLP far exceeds LPS as a gram-negative bacterial wall component, these findings therefore implicate BLP as an additional putative mediator of SIRS arising from gram-negative infection.

Adenosine A2A receptor activation reduces proinflammatory events and decreases cell death following intracerebral hemorrhage

The ubiquitous neuromodulator adenosine inhibits the production of several proinflammatory cytokines through activation of specific cell-surface adenosine receptors. We demonstrated recently that antisense oligonucleotides to tumor necrosis factor-alpha (TNF-alpha) are neuroprotective in a rat model of intracerebral hemorrhage. Therefore, we hypothesized that activation of adenosine receptors would provide protection against intracerebral hemorrhage-induced TNF-alpha production and inflammatory events. In vitro experiments showed that adenosine A1, A2A, and A3 receptor subtypes were present on U937 cells, and activation of these subtypes inhibited TNF-alpha production with a rank order of A2A > > A1 > A3. Prolonged treatment of U937 cells with the A2A receptor agonist 2-p-(carboxyethyl)phenethylamino-5'-N-ethylcarboxamidoadenosine hydrochloride (CGS 21680) desensitized adenosine A2A, A1, and A3 receptors. CGS 21680 administration directly into the striatum immediately prior to the induction of intracerebral hemorrhage inhibited TNF-alpha mRNA and, 24 hours following induction, reduced parenchymal neutrophil infiltration (p < 0.001) and TUNEL-positive cells (p < 0.002) within and bordering the hematoma. These results suggest that pharmacological strategies targeting A2A receptors may provide effective inhibition of acute neurotoxic proinflammatory events that occur following intracerebral hemorrhage.

Self-rated health and limiting longstanding illness: inter-relationships with morbidity in early adulthood

BACKGROUND

Self-rated health and limiting longstanding illness are both widely used global measures of health, but understanding is poor of their meaning and validity at younger ages.

METHODS

We examined the association between self-rated health and limiting longstanding illness and specific health problems at two ages (23 and 33 years), and assessed change over the 10-year period for each health measure relative to another. Longitudinal data were taken from the nationally representative British birth cohort for which health measures were obtained at ages 23 and 33.

RESULTS

Self-rated health and limiting longstanding illness were strongly associated with each other as well as with specific health problems, particularly with serious conditions (e.g. epilepsy, cancer, diabetes) and more weakly with less serious conditions (e.g. eczema and hay fever). Rating of overall health and limiting longstanding illness was highly stable during the 10-year period with most, but not all, health change reflecting a deterioration in health status. Deterioration in limiting illness corresponded to an even greater health decline in specific conditions.

CONCLUSIONS

Self-rated health and limiting longstanding illness are valid health measures appropriate for use in general health surveys.

Psychological distress and work and home roles: a focus on socio-economic differences in distress

BACKGROUND

Home and work factors have been linked to psychological status, but less is known about their contribution to social inequalities in psychological status. We examine whether social inequalities in psychological distress can be explained by work-home factors and whether the impact of these potential explanatory factors is similar for men and women.

METHODS

Data are from the 1958 British birth cohort study. We sought to explain social class differences in psychological distress at age 33. Explanatory factors were classified as work-home roles: i.e. employment, marital status, domestic responsibility, children and elderly care; and work-home characteristics: i.e. job-strain, insecurity, unsocial working hours, youngest child's age, number of children and level of involvement in childcare.

RESULTS

A social gradient in psychological distress was found: odds ratios for classes IV and V v. I and II were 2.65 (men) and 3.02 (women). Work factors had consistently stronger associations with psychological distress and with social class among men than women. Work factors had a greater impact on class differences in psychological distress in men. Associations for home roles and characteristics were less consistent and their combined effect on class differences in distress was negligible for both sexes.

CONCLUSION

Explanations for the social gradient differ for men and women. Work may be more important for men than women, but the impact of home factors was not strong during the early adulthood of this cohort.

Diminished adenosine A1 receptor expression on macrophages in brain and blood of patients with multiple sclerosis

The nucleoside adenosine has been shown to control the production of proinflammatory molecules through its actions on cell surface purine receptors. Previously, we have reported that the adenosine A1 receptor (A1AR) regulates tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) expression and exhibits diminished function in patients with multiple sclerosis (MS; Mayne et al., Ann Neurol 1999;45:633-639). In the present study, A1AR expression in both brain and peripheral blood mononuclear cells (PBMC) from MS and control groups was characterized by fluorescence-activated cell sorting (FACS), reverse transcriptase-polymerase chain reaction (RT-PCR), and immunohistochemical analyses. FACS analyses of PBMC revealed that A1AR expression was chiefly detectable on CD14-positive cells and was reduced by 53.1% (p < 0.01) in MS patients compared to controls. A1AR mRNA levels were reduced by 43.1% (p < 0.001) in the brains of MS patients compared to patients with other neurological diseases and controls. A1AR protein expression in brain was detected primarily in CD45-positive glial cells and was markedly diminished in MS patients. The analysis of A1AR transcripts in the brain revealed that the A1AR-beta transcript was diminished (49.2%) in MS patients compared to controls (p < 0.002). These results indicate that the A1AR, expressed principally on cells of monocyte/macrophage lineage in both brain and blood, is selectively diminished in MS patients. Reduction of the A1AR-beta transcript in MS patients suggests that dysregulated splicing may influence A1AR protein levels, potentially leading to increased macrophage activation and central nervous system inflammation.

Human immunodeficiency virus type 1 clade A and D neurotropism: molecular evolution, recombination, and coreceptor use

Human immunodeficiency virus type 1 (HIV-1) non-B clade viral infections of the brain have not been studied to date. Among nine AIDS patients from Nairobi, Kenya, infected with HIV-1 A (N = 5) or D (N = 4) clade strains, brain-derived HIV-1 env sequences displayed greater evolutionary distance than B clade brain-derived viruses (P < 0.001). Similarly, molecular diversity between matched brain and spleen env clones was clade-dependent and concentrated in the hypervariable V4 region (P < 0.001), with phylogenetic clustering of sequences derived from the same organ. Brain-derived A and D clade sequences displayed significantly lower ratios of nonsynonymous/synonymous substitution rates (d(N)/d(S)) compared to matched spleen-derived clones and brain-derived B clade viruses. Interclade recombination events were infrequently observed among the present env sequences. A chimeric virus containing the C2V3 region from an A clade brain-derived sequence preferentially used CD4 and CCR5 for infection. These findings demonstrate that differences in molecular diversity in brain-derived sequences were dependent on the individual clade and domain within the env gene, but both B and non-B clade brain-derived viruses exhibit a preference for CCR5 as a coreceptor.

HIV-1 reverse transcriptase sequence in plasma and cerebrospinal fluid of patients with AIDS dementia complex treated with Abacavir

OBJECTIVE

To assess HIV-1 RNA levels and the relationship between HIV-1 reverse transcriptase (RT) genotype from plasma and cerebrospinal fluid (CSF) during treatment with abacavir (Ziagen, ABC) or placebo in combination with stable background therapy (SBG) in subjects with AIDS dementia complex (ADC) (study CNA3001).

DESIGN

One-hundred and five HIV-1 infected adults with ADC were randomized to receive either ABC (600 mg twice daily) or ABC-matched placebo (twice daily) in addition to SBG for 12 weeks.

METHODS

Plasma and CSF were collected for population sequencing at baseline and week 12 (CSF optional). Sequences were analyzed for mutations associated with resistance to nucleoside reverse transcriptase inhibitors (NRTI).

RESULTS

Sixty out of sixty-seven subjects with baseline plasma HIV-RT sequence data harbored virus with > or = 1 NRTI-associated mutations; 50 out of 67 had the M184V mutation. At week 12, more subjects in the ABC group had plasma HIV-1 RNA < or = 400 copies/ml than the SBG group (46% versus 13%, P = 0.002). Non-response to ABC was associated with multiple baseline zidovudine (ZDV)/stavudine (d4T)-associated mutations. Baseline RT mutation patterns differed in 14 out of 21 (67%) paired samples from plasma and CSF. Four subjects experienced > 1 log10 copies/ml reductions in CSF HIV-1 RNA, two in the absence of reductions in plasma HIV-1 RNA and two with undetectable plasma HIV-1 RNA at baseline.

CONCLUSIONS

Substantial decreases in plasma and CSF HIV-1 RNA following addition of ABC were not precluded by baseline HIV-1 NRTI-associated mutations, including the M184V mutation, but non-responders commonly harbored multiple ZDV/d4T-associated mutations. HIV-1 RNA responses and RT genotype appear to be discordant between CSF and plasma in some subjects.

Physical and psychological effects of injury. Data from the 1958 British birth cohort study

BACKGROUND

There is only scant evidence for the long-term health effects of road traffic injuries. We therefore assessed the extent to which motor vehicle driver injuries influence limiting long-standing illness and psychological distress using data from a nationwide study (the 1958 British birth cohort) in early adulthood.

METHODS

Information was obtained on driver injuries occurring between ages 23 and 33 years and limiting illnesses and psychological distress at age 33 years. The risks of injury-related adverse consequences were derived using logistic regression and expressed as odds ratios (ORs) and 95% confidence intervals.

RESULTS

A single injury was associated with limiting illness (OR = 2.01 and 95% CI: 1.38-2.94). The association between a single injury and psychological distress was strong for a recent injury occurring between ages 30 and 33 years (OR = 1.86 and 95% CI: 1.24-2.81), but not for injuries occurring earlier on. The population attributable fraction for limiting illness with one injury was 3.8% (range 1.7-5.3%) and with two or more injuries was 1.0% (range 0.5-1.3%). After controlling for potential confounding factors the corresponding figures were 4.2% (range 2.2-5.6%) and 1.1% (range 0.5-1.3%) respectively.

CONCLUSIONS

Driver injuries are associated with a substantial increase in disability and, also in the short term, with increases in psychological distress. These results highlight the need for identifying effective strategies for the prevention of road traffic injuries as well as more effective approaches for rehabilitation of the injured.

Retroviral diseases of the nervous system: pathogenic host response or viral gene-mediated neurovirulence?

Retroviruses represent an important group of RNA viruses that cause a spectrum of nervous system diseases. Furthermore, newly recognized retroviral infections of the nervous system and some retroviral vectors or proteins used for gene delivery raise potential safety concerns. This article highlights different retroviruses and their causative mechanisms of nervous system disease, or neurovirulence. Specific sequences within retroviral genes might determine the development of neurovirulence. Conversely, neurovirulent retroviruses also activate host immune responses, resulting in a neuropathogenic cascade that is mediated by pro-inflammatory and neurotoxic molecules, ultimately culminating in neuronal death. Thus, retroviral infections of the nervous system illustrate a molecular interplay between distinct infectious agents and pathogenic host responses, which results in neurovirulence.