Inflammation in CNS neurodegenerative diseases

Neurodegenerative diseases, the leading cause of morbidity and disability, are gaining increased attention as they impose a considerable socioeconomic impact, due in part to the ageing community. Neuronal damage is a pathological hallmark of Alzheimer's and Parkinson's diseases, amyotrophic lateral sclerosis, Huntington's disease, spinocerebellar ataxia and multiple sclerosis, although such damage is also observed following neurotropic viral infections, stroke, genetic white matter diseases and paraneoplastic disorders. Despite the different aetiologies, for example, infections, genetic mutations, trauma and protein aggregations, neuronal damage is frequently associated with chronic activation of an innate immune response in the CNS. The growing awareness that the immune system is inextricably involved in shaping the brain during development as well as mediating damage, but also regeneration and repair, has stimulated therapeutic approaches to modulate the immune system in neurodegenerative diseases. Here, we review the current understanding of how astrocytes and microglia, as well as neurons and oligodendrocytes, shape the neuroimmune response during development, and how aberrant responses that arise due to genetic or environmental triggers may predispose the CNS to neurodegenerative diseases. We discuss the known interactions between the peripheral immune system and the brain, and review the current concepts on how immune cells enter and leave the CNS. A better understanding of neuroimmune interactions during development and disease will be key to further manipulating these responses and the development of effective therapies to improve quality of life, and reduce the impact of neuroinflammatory and degenerative diseases.

Excitatory amino acid projections to the nucleus accumbens septi in the rat: a retrograde transport study utilizing D[3H]aspartate and [3H]GABA

Afferents to the nucleus accumbens septi utilizing glutamate or aspartate have been investigated in the rat by autoradiography following injection and retrograde transport of D[3H]aspartate. Parallel experiments with the intra-accumbal injection of [3H]GABA were employed to establish the transmitter-selective nature of the retrograde labelling found with D[3H]aspartate. The topography of cortical and thalamic perikarya labelled by D[3H]aspartate was extremely precise. D[3H]Aspartate labelled perikarya were found in layer V of agranular insular cortex; bilaterally within prelimbic and infralimbic subareas perikarya, but predominantly ipsilaterally. Ipsilateral labelling was observed in dorsal, ventral and posterior agranular insular cortices, and in perirhinal cortex. Injections into ventral accumbens labelled perikarya in ipsilateral entorhinal cortex, while infusion of D[3H]aspartate into anterior caudate-putamen resulted in labelling of perikarya in ipsilateral cingulate and lateral precentral cortices. Following infusion of D[3H]aspartate, ipsilateral midline thalamic nuclei contained the highest density of labelled perikarya; infusions centred on nucleus accumbens resulted in heavy retrograde labelling of the parataenial nucleus, but labelling was sparse from a lateral site and not observed after injection into anterior caudate-putamen. Less prominent labelling of perikarya was seen in other thalamic nuclei (mediodorsal, central medial, rhomboid, reuniens and centrolateral), mostly near the midline. Perikaryal labelling was also found in the ipsilateral amygdaloid complex, particularly in basolateral and lateral nuclei. Only weak labelling resulted in ventral subiculum. Numerous labelled cells were present bilaterally in anterior olfactory nucleus, although perikarya were more prominent ipsilaterally. Labelled perikarya were not consistently observed in other regions (ventral tegmental area, medial substantia nigra, raphe nuclei and locus coeruleus) known to innervate nucleus accumbens. Presumptive anterograde labelling was detected in ventral pallidum/substantia innominata, ventral tegmental area and medial substantia nigra. [3H]GABA was generally not retrogradely transported to the same regions labelled by D[3H]aspartate; an exception being the anterior olfactory nucleus, where large numbers of labelled perikarya were found. [3H]GABA failed to label perikarya in thalamus and amygdala, and a topographic distribution of label was absent in neocortex.(ABSTRACT TRUNCATED AT 400 WORDS)

TDP-43 gains function due to perturbed autoregulation in a Tardbp knock-in mouse model of ALS-FTD

Amyotrophic lateral sclerosis-frontotemporal dementia (ALS-FTD) constitutes a devastating disease spectrum characterized by 43-kDa TAR DNA-binding protein (TDP-43) pathology. Understanding how TDP-43 contributes to neurodegeneration will help direct therapeutic efforts. Here we have created a TDP-43 knock-in mouse with a human-equivalent mutation in the endogenous mouse Tardbp gene. TDP-43Q331K mice demonstrate cognitive dysfunction and a paucity of parvalbumin interneurons. Critically, TDP-43 autoregulation is perturbed, leading to a gain of TDP-43 function and altered splicing of Mapt, another pivotal dementia-associated gene. Furthermore, a new approach to stratify transcriptomic data by phenotype in differentially affected mutant mice revealed 471 changes linked with improved behavior. These changes included downregulation of two known modifiers of neurodegeneration, Atxn2 and Arid4a, and upregulation of myelination and translation genes. With one base change in murine Tardbp, this study identifies TDP-43 misregulation as a pathogenic mechanism that may underpin ALS-FTD and exploits phenotypic heterogeneity to yield candidate suppressors of neurodegenerative disease.

Clusterin regulates β-amyloid toxicity via Dickkopf-1-driven induction of the wnt-PCP-JNK pathway

Although the mechanism of Aβ action in the pathogenesis of Alzheimer's disease (AD) has remained elusive, it is known to increase the expression of the antagonist of canonical wnt signalling, Dickkopf-1 (Dkk1), whereas the silencing of Dkk1 blocks Aβ neurotoxicity. We asked if clusterin, known to be regulated by wnt, is part of an Aβ/Dkk1 neurotoxic pathway. Knockdown of clusterin in primary neurons reduced Aβ toxicity and DKK1 upregulation and, conversely, Aβ increased intracellular clusterin and decreased clusterin protein secretion, resulting in the p53-dependent induction of DKK1. To further elucidate how the clusterin-dependent induction of Dkk1 by Aβ mediates neurotoxicity, we measured the effects of Aβ and Dkk1 protein on whole-genome expression in primary neurons, finding a common pathway suggestive of activation of wnt-planar cell polarity (PCP)-c-Jun N-terminal kinase (JNK) signalling leading to the induction of genes including EGR1 (early growth response-1), NAB2 (Ngfi-A-binding protein-2) and KLF10 (Krüppel-like factor-10) that, when individually silenced, protected against Aβ neurotoxicity and/or tau phosphorylation. Neuronal overexpression of Dkk1 in transgenic mice mimicked this Aβ-induced pathway and resulted in age-dependent increases in tau phosphorylation in hippocampus and cognitive impairment. Furthermore, we show that this Dkk1/wnt-PCP-JNK pathway is active in an Aβ-based mouse model of AD and in AD brain, but not in a tau-based mouse model or in frontotemporal dementia brain. Thus, we have identified a pathway whereby Aβ induces a clusterin/p53/Dkk1/wnt-PCP-JNK pathway, which drives the upregulation of several genes that mediate the development of AD-like neuropathologies, thereby providing new mechanistic insights into the action of Aβ in neurodegenerative diseases.

Initial paclitaxel improves outcome compared with CMFP combination chemotherapy as front-line therapy in untreated metastatic breast cancer

PURPOSE

To determine the place of single-agent paclitaxel compared with nonanthracycline combination chemotherapy as front-line therapy in metastatic breast cancer.

PATIENTS AND METHODS

Patients with previously untreated metastatic breast cancer were randomized to receive either paclitaxel 200 mg/m(2) intravenously (IV) over 3 hours for eight cycles (24 weeks) or standard cyclophosphamide 100 mg/m(2)/d orally on days 1 to 14, methotrexate 40 mg/m(2) IV on days 1 and 8, fluorouracil 600 mg/m(2) IV on days 1 and 8, and prednisone 40 mg/m(2)/d orally on days 1 to 14 (CMFP) for six cycles (24 weeks) with epirubicin recommended as second-line therapy.

RESULTS

A total of 209 eligible patients were randomized with a median survival duration of 17.3 months for paclitaxel and 13.9 months for CMFP. Multivariate analysis showed that patients who received paclitaxel survived significantly longer than those who received CMFP (P =.025). Paclitaxel produced significantly less severe leukopenia, thrombocytopenia, mucositis, documented infections (all P <.001), nausea or vomiting (P =.003), and fever without documented infection (P =.007), and less hospitalization for febrile neutropenia than did CMFP (P =.001). Alopecia, peripheral neuropathy, and myalgia or arthralgia were more severe with paclitaxel (all P <.0001). Overall, quality of life was similar for both treatments (P > = .07).

CONCLUSION

Initial paclitaxel was associated with significantly less myelosuppression and fewer infections, with longer survival and similar quality of life and control of metastatic breast cancer compared with CMFP.

Natural history of autoimmune thyroiditis

One hundred and sixty-three asymptomatic people with thyroid antibodies or raised serum thyrotrophin (TSH) concentrations, or both, and 209 age-matched and sex-matched controls without either marker of thyroid disorder were followed up for four years to determine the natural history of autoimmune thyroiditis. Mildly raised TSH concentrations alone and the presence of thyroid antibodies alone did not significantly increase the risk of developing overt hypothyroidism during the four years compared with the controls. Overt hypothyroidism developed at the rate of 5% a year in women who initially had both raised TSH concentrations and thyroid antibodies. Prophylactic treatment with thyroxine may be justified in women found to have both markers of impending thyroid failure. The cost effectiveness of screening the adult population remains to be evaluated.

Retinopathy and vision loss in insulin-dependent diabetes in Europe. The EURODIAB IDDM Complications Study

PURPOSE

To assess the frequency of retinopathy and vision loss in patients with insulin-dependent diabetes mellitus and their relations to potentially modifiable risk factors.

METHODS

The authors conducted a multicenter cross-sectional study of diabetic complications and their risk factors using standardized methods of assessment. The sample was comprised of 3250 insulin-dependent diabetic patients (1668 men, 1582 women) aged 15 to 60 years with mean (standard deviation) duration of diabetes of 14.7 (9.3) years from 31 European diabetes centers; 2991 of the patients were eligible for retinal photography. Visual acuity was measured using the Snellen chart. Retinopathy was evaluated by retinal photographs (two fields per eye) graded at a central facility. Glycated hemoglobin (HbA1c), cholesterol, triglyceride, fibrinogen, von Willebrand factor, and urinary albumin excretion rate were assessed at a single location.

RESULTS

Corrected visual acuity was greater than or equal to 1.0 in both eyes in 69.7% of patients and less than or equal to 0.1 in the best eye in 2.3%. Factors significantly related to vision loss were age, duration of diabetes, glycated hemoglobin (HbA1c), and level of retinopathy. Mild nonproliferative retinopathy was found in 25.8% of the patients, moderate-severe nonproliferative retinopathy in 9.8% of the patients, and proliferative retinopathy in 10.6% of the patients. After adjustment for age, duration of diabetes, HbA1c, and albumin excretion rate, significant risk factors for moderate-severe nonproliferative retinopathy were blood pressure and triglyceride, and risk factors for proliferative retinopathy were triglyceride and fibrinogen.

CONCLUSION

Vision loss is a common complication of patients with insulin-dependent diabetes, with diabetic retinopathy an important cause. Apart from poor glycemic control, several other potentially modifiable risk factors for retinopathy may be important, including elevated blood pressure, plasma triglyceride, and fibrinogen. In view of the possible barriers to the full implementation of strict glycemic control in this type of diabetes, additional strategies for the prevention and slowing of progression of retinopathy should be investigated, such as blood pressure and lipid lowering therapies.

Cardiovascular disease and its risk factors in IDDM in Europe. EURODIAB IDDM Complications Study Group

OBJECTIVE

To study the prevalence of cardiovascular disease (CVD), its risk factors, and their associations in IDDM patients in different European countries.

RESEARCH DESIGN AND METHODS

The prevalence of CVD (a past history or electrocardiogram abnormalities) and its risk factors were examined in a cross-sectional study in 3,250 IDDM patients from 16 European countries (EURODIAB IDDM Complications Study). The patients were examined in 31 centers and were stratified between centers for age, sex, and duration of diabetes. The mean +/- SD duration of diabetes was 14.7 +/- 9.3 years.

RESULTS

The prevalence of CVD was 9% in men and 10% in women. The prevalence increased with age (from 6% in patients 15-29 years old to 25% in patients 45-59 years old) and with duration of diabetes. The between-center variation for the whole population was from 3 to 19%. In both sexes, fasting triglyceride concentration was higher and HDL cholesterol lower in those patients with CVD than in those without. In men, duration of diabetes was longer, waist-to-hip ratio greater, and hypertension more common in patients with CVD. In women, a greater BMI was associated with increased prevalence of CVD. There was no association between insulin dose, HbA1c level, age-adjusted rate of albumin excretion, or smoking status and CVD. Waist-to-hip ratio, particularly in men, was positively associated with age, age-adjusted HbA1c, prevalence of smoking, daily insulin dose, albumin excretion rate, and fasting triglyceride concentrations.

CONCLUSIONS

The overall prevalence of CVD in these IDDM patients was approximately 10%, increasing with age and duration of diabetes and with a sixfold variation between different European centers. CVD prevalence was most strongly associated with elevated triglyceride and decreased HDL cholesterol concentrations. CVD was also associated with albuminuria, but when adjusted by age, this association vanished. Increasing waist-to-hip ratio was associated with a number of adverse characteristics, particularly in IDDM men, reflecting the metabolic syndrome previously described in other populations.

Deficiency of the human mitochondrial transcription factor h-mtTFA in infantile mitochondrial myopathy is associated with mtDNA depletion

Recent studies show that patients presenting with cytochrome oxidase (COX) deficiency in infancy may have reduced mitochondrial DNA (mtDNA) in muscle. The human mitochondrial transcription factor A (h-mtTFA) may be an important regulator of both transcription and replication of mtDNA. h-mtTFA levels were investigated in cell lines which were either free of mtDNA (rho 0) or temporarily depleted by treatment with dideoxycytidine (ddC), and in tissue from three patients with mtDNA depletion and cytochrome oxidase deficiency. h-mtTFA was compared with other mitochondrial proteins such as pyruvate dehydrogenase and porin by Western blotting. The ratio of mtDNA and h-mtTFA mRNA to reference nuclear probes was measured by dual labelling of dot blots. The ratio of mtDNA to nuclear DNA in skeletal muscle was low in muscle in the three patients and in other tissues in one. h-mtTFA was low in cells depleted either permanently or transiently of mtDNA, and this reduction in h-mtTFA roughly paralleled mtDNA levels. Similarly, treatment of rho 0 cell lines with ddC induced a reduction in mtDNA as well as h-mtTFA protein. The relationship between h-mtTFA and mtDNA levels suggests that they may be causally linked. MtDNA depletion was accompanied by an increase in the level of h-mtTFA RNA in the cell lines but low levels in the patient. This suggests that either h-mtTFA regulates mtDNA levels, or that h-mtTFA expression may be regulated by a feedback mechanism initiated by MtDNA Depletion.

The occurrence of tolerance to a central depressant effect of nicotine

1. Rats were injected with 0.8 mg nicotine/kg, 0.8 mg amphetamine/kg or with saline immediately before being tested for 30 min in activity boxes.2. During the first 3 trials the nicotine group were less active than the controls but from trial 5 onwards nicotine had a stimulant effect. The stimulant effect of the amphetamine did not alter with repeated injection.

Phase I and pharmacokinetic study of paclitaxel in combination with biricodar, a novel agent that reverses multidrug resistance conferred by overexpression of both MDR1 and MRP

PURPOSE

To evaluate the feasibility of administering biricodar (VX-710; Incel, Vertex Pharmaceuticals Inc, Cambridge, MA), an agent that modulates multidrug resistance (MDR) conferred by overexpression of both the multidrug resistance gene product (MDR1) P-glycoprotein and the MDR-associated protein (MRP) in vitro, in combination with paclitaxel. The study also sought to determine the maximum-tolerated dose (MTD) of paclitaxel that could be administered with biologically relevant concentrations of VX-710 and characterize the toxicologic and pharmacologic profiles of the VX-710/ paclitaxel regimen.

PATIENTS AND METHODS

Patients with solid malignancies were initially treated with VX-710 as a 24-hour infusion at doses that ranged from 10 to 120 mg/m2 per hour. After a 2-day washout period, patients were re-treated with VX-710 on an identical dose schedule followed 8 hours later by paclitaxel as a 3-hour infusion at doses that ranged from 20 to 80 mg/m2. The pharmacokinetics of both VX-710 and paclitaxel were studied during treatment with VX-710 alone and VX-710 and paclitaxel. Thereafter, patients received VX-710 and paclitaxel every 3 weeks.

RESULTS

VX-710 alone produced minimal toxicity. The toxicologic profile of the VX-710/paclitaxel regimen was similar to that reported with paclitaxel alone; neutropenia that was noncumulative was the principal dose-limiting toxicity (DLT). The MTD levels of VX-710/ paclitaxel were 120 mg/m2 per hour and 60 mg/m2, respectively, in heavily pretreated patients and 120/60 to 80 mg/m2 per hour in less heavily pretreated patients. At these dose levels, VX-710 steady-state plasma concentrations (Css) ranged from 2.68 to 4.89 microg/mL, which exceeded optimal VX-710 concentrations required for MDR reversal in vitro. The pharmacokinetics of VX-710 were dose independent and not influenced by paclitaxel. In contrast, VX-710 reduced paclitaxel clearance. At the two highest dose levels, which consisted of VX-710 120 mg/m2 per hour and paclitaxel 60 and 80 mg/m2, pertinent pharacokinetic determinants of paclitaxel effect were similar to those achieved with paclitaxel as a 3-hour infusion at doses of 135 and 175 mg/m2, respectively.

CONCLUSION

VX-710 alone is associated with minimal toxicity. In combination with paclitaxel, biologically relevant VX-710 plasma concentrations are achieved and sustained for 24 hours, which simulates optimal pharmacologic conditions required for MDR reversal in vitro. The acceptable toxicity profile of the VX-710/ paclitaxel combination and the demonstration that optimal pharmacologic conditions for MDR reversal are achievable support a rationale for further trials of VX710/paclitaxel in patients with malignancies that are associated with de novo or acquired resistance to paclitaxel caused by overexpression of MDR1 and/or MRP.

L-dihydroxyphenylalanine: effect on S-adenosylmethionine in brain

Forty-five minutes after intraperitoneal injection of a single dose (100 milligrams per kilogram) of L-dihydroxyphenylalanine, the concentration of S-adenosylmethionine in rat brain was lowered by 76 percent. As little as 10 milligrams of L-dihydroxyphenylalanine per kilogram decreased content of S-adenosylmethionine in the adrenal medulla by 51 percent, whereas 100 milligrams per kilogram did not significantly depress concentration of S-adenosylmethionine in the liver in this time interval. Concentration of S-adenosylmethionine in the brain varied diurnally; L-dihydroxyphenylalanine lowered this concentration whether administered at the daily peak or at the nadir.

Selective versus universal antenatal HIV testing: epidemiological and implementational factors in policy choice

OBJECTIVE

To develop an epidemiological basis for economic analyses of selective and universal antenatal screening strategies, and to apply it to the UK.

METHODS

The prevalence of higher-risk women and the prevalence of undiagnosed infection within groups of high-risk and low-risk women was estimated from surveillance and survey data. The numbers of women tested and the numbers of infected women who would be identified by universal and selective strategies were then calculated under a range of assumptions about the identification of higher-risk women and acceptance of testing.

RESULTS

In higher-risk women estimated prevalence of undiagnosed infection was between 0.06% and 2.8%, comparing well with independent estimates. In low-risk women, estimates ranged from 0.014% in London to 0.002% in the rest of the UK. If uptake among the high-risk women was the same in selective and universal strategies, universal testing would entail testing between 7100 (London) and 50000 (rest of England) additional women to detect an additional case. However, if selective screening identified only 60% of those at high risk and achieved only 60% acceptance compared with a universal programme, then universal screening would require only 1150 additional women to identify one additional case in London, compared to 6470 in Scotland and 13140 in the rest of the UK.

CONCLUSIONS

Overall prevalence does not form an adequate basis for determining screening strategy. Instead, universal screening can be justified either because the prevalence of HIV in the low-risk group is sufficiently high, or because it achieves sufficiently higher uptake relative to selective screening among those at higher risk.

The association between obesity and quality of life: a retrospective analysis of a large-scale population-based cohort study

BACKGROUND

The relationship between obesity and health-related quality of life (HRQoL) may be confounded by factors such as multimorbidity. The aim of the study was to explore this relationship, controlling for long-term conditions and other health, lifestyle and demographic factors in a general adult population. There was specific interest in the impact of high weight status, measured by body mass index (BMI) levels (obesity, morbid obesity) compared with individuals of normal weight.

METHODS

Health, lifestyle and demographic data were collected from 64,631 individuals aged 16 years and over registered in the Yorkshire Health Study; a long-term cohort study. Data were collected in 2 waves: from patients attending GP surgeries in the South Yorkshire region; and using online recruitment across the entire Yorkshire and Humber area. Univariable and multivariable regression methods were utilised to identify factors associated with HRQoL as measured by the EQ-5D summary score. Long-term conditions were tested as both covariates and mediating factors on the causal pathway between obesity and HRQoL.

RESULTS

Increasing levels of obesity are associated with reduced HRQoL, although this difference is negligible between those of normal weight and those who are overweight. Individuals with obesity and morbid obesity score 4.9 and 11.3 percentage points less on the EQ-5D summary scale respectively than those of normal weight. Concurrent physical, and particularly mental health-related long-term conditions are substantively related to HRQoL: those with 3 or more reported mental or physical health conditions score 29.8 and 14.6 percentage points less on the EQ-5D summary scale respectively than those with fewer conditions. Long-term conditions can be conceptualised as lying on the causal path between obesity and HRQoL, but there is weak evidence for a partial mediating relationship only.

CONCLUSIONS

To conclude, in agreement with the established literature we have found a clear inverse relationship between increasing weight status and decreasing HRQoL and confirmed the mediating role of long-term conditions in the reduction of HRQoL in people with obesity. Nevertheless, a high BMI remains independently related to HRQoL, suggesting that 'healthy people with obesity' may be in transition to an unhealthy future.

Phase I and pharmacokinetic trial of oral irinotecan administered daily for 5 days every 3 weeks in patients with solid tumors

PURPOSE

We conducted a phase I dose-escalation trial of orally administered irinotecan (CPT-11) to characterize the maximum-tolerated dose (MTD), dose-limiting toxicities (DLTs), pharmacokinetic profile, and antitumor effects in patients with refractory malignancies.

PATIENTS AND METHODS

CPT-11 solution for intravenous (IV) use was mixed with CranGrape juice (Ocean Spray, Lakeville-Middleboro, MA) and administered orally once per day for 5 days every 3 weeks to 28 patients. Starting dosages ranged from 20 to 100 mg/m2/d.

RESULTS

Grade 4 delayed diarrhea was the DLT at the 80 mg/m2/d dosage in patients younger than 65 years of age and at the 66 mg/m2/d dosage in patients 65 or older. The other most clinically significant toxicity of oral CPT-11 was neutropenia. A linear relationship was found between dose, peak plasma concentration, and area under the concentration-time curve (AUC) for both CPT-11 and SN-38 lactone, implying no saturation in the conversion of irinotecan to SN-38. The mean metabolic ratio ([AUC(SN-38 total) + AUC(SN-38G total)]/AUC(CPT-11 total)) was 0.7 to 0.8, which suggests that oral dosing results in presystemic conversion of CPT-11 to SN-38. An average of 72% of SN-38 was maintained in the lactone form during the first 24 hours after drug administration. One patient with previously treated colorectal cancer and liver metastases who received oral CPT-11 at the 80 mg/m2/d dosage achieved a confirmed partial response.

CONCLUSION

The MTD and recommended phase II dosage for oral CPT-11 is 66 mg/m2/d in patients younger than 65 years of age and 50 mg/m2/d in patients 65 or older, administered daily for 5 days every 3 weeks. The DLT of diarrhea is similar to that observed with IV administration of CPT-11. The biologic activity and favorable pharmacokinetic characteristics make oral administration of CPT-11 an attractive option for further clinical development.

A phase II, multicenter, open-label randomized study of motesanib or bevacizumab in combination with paclitaxel and carboplatin for advanced nonsquamous non-small-cell lung cancer

BACKGROUND

This phase II study estimated the difference in objective response rate (ORR) among patients with advanced nonsquamous non-small-cell lung cancer (NSCLC) receiving paclitaxel-carboplatin (CP) plus motesanib or bevacizumab.

PATIENTS AND METHODS

Chemotherapy-naive patients (N = 186) were randomized 1:1:1 to receive CP plus motesanib 125 mg once daily (qd) (arm A), motesanib 75 mg twice daily (b.i.d.) 5 days on/2 days off (arm B), or bevacizumab 15 mg/kg every 3 weeks (q3w) (arm C). The primary end point was ORR (per RECIST). Other end points included progression-free survival (PFS), overall survival (OS), motesanib pharmacokinetics, and adverse events (AEs).

RESULTS

ORRs in the three arms were as follows: arm A, 30% (95% confidence interval 18% to 43%); arm B, 23% (13% to 36%); and arm C, 37% (25% to 50%). Median PFS in arm A was 7.7 months, arm B 5.8 months, and arm C 8.3 months; median OS for arm A was 14.0 months, arm B 12.8 months, and arm C 14.0 months. Incidence of AEs was greater in arms A and B than in arm C. More grade 5 AEs not attributable to disease progression occurred in arm B (n = 10) than in arms A (n = 4) and C (n = 4). Motesanib plasma C(max) and C(min) values were consistent with its pharmacokinetic properties observed in previous studies.

CONCLUSIONS

The efficacy of 125 mg qd motesanib or bevacizumab plus CP was estimated to be comparable. Toxicity was higher but manageable in both motesanib arms. Efficacy and tolerability of motesanib 125 mg qd plus CP in advanced nonsquamous NSCLC are being further investigated in a phase III study.

A quantitative neuropathological assessment of translocator protein expression in multiple sclerosis

The 18 kDa translocator protein (TSPO) is increasingly used to study brain and spinal cord inflammation in degenerative diseases of the CNS such as multiple sclerosis. The enhanced TSPO PET signal that arises during disease is widely considered to reflect activated pathogenic microglia, although quantitative neuropathological data to support this interpretation have not been available. With the increasing interest in the role of chronic microglial activation in multiple sclerosis, characterising the cellular neuropathology associated with TSPO expression is of clear importance for understanding the cellular and pathological processes on which TSPO PET imaging is reporting. Here we have studied the cellular expression of TSPO and specific binding of two TSPO targeting radioligands (3H-PK11195 and 3H-PBR28) in tissue sections from 42 multiple sclerosis cases and 12 age-matched controls. Markers of homeostatic and reactive microglia, astrocytes, and lymphocytes were used to investigate the phenotypes of cells expressing TSPO. There was an approximate 20-fold increase in cells double positive for TSPO and HLA-DR in active lesions and in the rim of chronic active lesion, relative to normal appearing white matter. TSPO was uniformly expressed across myeloid cells irrespective of their phenotype, rather than being preferentially associated with pro-inflammatory microglia or macrophages. TSPO+ astrocytes were increased up to 7-fold compared to normal-appearing white matter across all lesion subtypes and accounted for 25% of the TSPO+ cells in these lesions. To relate TSPO protein expression to ligand binding, specific binding of the TSPO ligands 3H-PK11195 and 3H-PBR28 was determined in the same lesions. TSPO radioligand binding was increased up to seven times for 3H-PBR28 and up to two times for 3H-PK11195 in active lesions and the centre of chronic active lesions and a strong correlation was found between the radioligand binding signal for both tracers and the number of TSPO+ cells across all of the tissues examined. In summary, in multiple sclerosis, TSPO expression arises from microglia of different phenotypes, rather than being restricted to microglia which express classical pro-inflammatory markers. While the majority of cells expressing TSPO in active lesions or chronic active rims are microglia/macrophages, our findings also emphasize the significant contribution of activated astrocytes, as well as smaller contributions from endothelial cells. These observations establish a quantitative framework for interpretation of TSPO in multiple sclerosis and highlight the need for neuropathological characterization of TSPO expression for the interpretation of TSPO PET in other neurodegenerative disorders.

Excitatory amino acid projections to the periaqueductal gray in the rat: a retrograde transport study utilizing D[3H]aspartate and [3H]GABA

The afferents to the periaqueductal gray utilizing excitatory amino acid transmitters have been described in rat brain by autoradiography following microinfusion and retrograde transport of D[3H]aspartate. Parallel experiments employing injections of [3H]GABA established that the retrograde labelling found with D[3H]aspartate was transmitter-selective. Following infusion of D[3H]aspartate, perikaryal labelling was found in nine subcortical areas, particularly infralimbic and cingulate cortices, with a predominance of ipsilateral labelled perikarya. Heaviest cortical labelling was localized in perirhinal cortex, in an extensive band of cells adjoining the rhinal sulcus. The hypothalamus contained the heaviest perikaryal labelling within brain: D[3H]aspartate labelled cells in 11 hypothalamic and mammillary nuclei. Intense bilateral labelling was obtained in ventromedial hypothalamus, although the number of perikarya was lower contralaterally. D[3H]Aspartate also produced heavy ipsilateral labelling of perikarya in posterior hypothalamus. Labelling patterns in cortex and hypothalamus were precise and topographic, and [3H]GABA never labelled cells in these regions. Other telencephalic and diencephalic areas containing prominent, retrogradely labelled cells were the lateral septum, amygdala, zona incerta and lateral habenula. The relative density of labelled cells in mesencephalic areas was much lower than that found in cortex and hypothalamus, although D[3H]aspartate labelled a moderate number of perikarya in the inferior colliculus and cuneiform nucleus. A smaller number of heavily labelled cells was found in the parabrachial nuclei, Kolliker-Fuse nucleus and laterodorsal tegmental nucleus. Only occasional labelled perikarya were observed in the myencephalon. Low densities of labelled cells were found after the injection of [3H]GABA into the periaqueductal gray, and the only regions in which a small number of perikarya were labelled by both [3H]GABA and D[3H]aspartate were the dorsal raphe and parabrachial nuclei. Overall, the retrograde transport of D[3H]aspartate revealed a complex topographic and convergent network of afferent pathways to the periaqueductal gray likely to utilize an excitatory amino acid transmitter. Our findings confirm the selectivity of this neurochemical mapping technique and provide evidence that hypothalamic, habenular, subthalamic and cuneiform afferents to the periaqueductal gray utilize an acidic amino acid as their transmitter. They also confirm that corticofugal afferents to periaqueductal gray utilize an excitatory amino acid.

Disease progression and survival in HIV-1-infected Africans in London

OBJECTIVE

To examine differences in progression to AIDS and death between HIV-1-positive Africans (most infected in sub-Saharan Africa and therefore with non-B subtypes) and HIV-1-positive non-Africans in London.

DESIGN

Retrospective cohort study of 2048 HIV-1-positive individuals.

SETTING

HIV-1-infected individuals attending 11 of the largest HIV/AIDS units in London.

PATIENTS

Subjects were 1056 Africans and 992 non-Africans seen between 1982-1995.

RESULTS

There were no differences in crude survival from presentation to death between Africans and non-Africans (median 82 and 78 months, respectively; P = 0.22). Africans progressed more rapidly to AIDS [hazard ratio (HR), 1.21; 95% confidence interval (CI), 1.02-1.45] but after adjustment for age, sex, Centers for Disease Control and Prevention category B symptoms and CD4+ lymphocyte count at presentation, year of HIV diagnosis and hospital attended, this difference was no longer significant (adjusted HR, 1.15; 95% CI, 0.93-1.43). Africans with AIDS had a reduced risk of death compared with non-Africans (HR, 0.78; 95% CI, 0.63-0.96) but not after adjustment for age, CD4+ lymphocyte count at AIDS, initial AIDS-defining conditions (ADC) and hospital attended (HR, 0.98; 95% CI, 0.76-1.27). Tuberculosis as the first ADC was associated with a 64% reduction in the risk of death. CD4+ lymphocyte decline was not significantly different between Africans and non-Africans (P = 0.18).

CONCLUSIONS

Differences in progression to AIDS and death and CD4+ lymphocyte decline between HIV-1-infected Africans and non-Africans in London could not be attributed to ethnicity or different viral subtypes. Age and the clinical and immunological stage at presentation, or AIDS, were the major determinants of outcome. Compared with other diagnoses, tuberculosis as the initial ADC was associated with increased survival. Lack of access to health care and exposure to environmental pathogens are the most likely causes of reduced survival with AIDS in Africa, rather than inherently different rates of progression of immune deficiency due to racial differences or viral subtypes.

Autoradiographic analysis of receptors on vascular endothelium

Receptor autoradiography was used to examine the distribution of muscarinic cholinoceptors ([3H]QNB), alpha 2-adrenoceptors ([3H]rauwolscine), beta-adrenoceptors ([125I]CYP) and substance P receptors ([125I]BHSP) in rabbit aorta, pulmonary artery, rat aorta, dog aorta, splenic, renal and coronary arteries, bovine aorta and coronary arteries. Muscarinic cholinoceptors and alpha 2-adrenoceptors were not associated with endothelium in any of the blood vessels examined. Substance P receptors were found on endothelium in dog renal but not bovine coronary arteries, and beta-adrenoceptors were found on endothelium in dog coronary arteries but not bovine aorta. The results suggest that endothelium-dependent relaxation can result either from activation of receptors located directly on the endothelial cells or, as is the case for ACh, by an indirect mechanism via activation of receptors located on the vascular smooth muscle.

Prediction of mortality in adult emergency department patients with sepsis

OBJECTIVES

To determine the efficacy of the abbreviated Mortality in Emergency Department Sepsis (MEDS) score, the Modified Early Warning (MEW) score and near-patient-test (NPT) lactate levels in predicting 28-day mortality in adult emergency department (ED) patients with sepsis.

METHODS

A retrospective cohort study of adult ED patients with sepsis admitted to hospital was conducted in a large urban teaching and a district general hospital. Data were collected during four time periods between 1 January 2006 and 31 January 2007. Inclusion criteria were age > or =16 years and an ED diagnosis of sepsis. Primary outcome for all patients was 28-day mortality. Patients were preassigned to risk groups according to their abbreviated MEDS score, MEW score and NPT lactate.

RESULTS

307 ED patients with sepsis were included in the study. Among these there were 72 deaths (23%). Mortality rates for the low-, moderate- and high-risk groups of the abbreviated MEDS score were 1/63 (1.6%), 48/205 (23.4%) and 23/39 (59.0%) patients. The MEDS score for low-risk patients was 98.6% (95% CI 92.5% to 99.9%) sensitive and 26.5% (95% CI 21.0% to 32.6%) specific and for high-risk patients it was 31.9% (95% CI 21.4% to 44.0%) sensitive and 93.2% (95% CI 89.2% to 96.1%) specific for death within 28 days. Mortality rates for the low- and high-risk MEW score were 20/159 (12.6%) and 52/148 (35.1%) patients. The MEW score for high-risk patients was 72.2% (95% CI 60.4% to 82.1%) sensitive and 59.2% (95% CI 52.6% to 65.5%) specific for mortality. An NPT lactate level of > or =4 mmol/l was 49.1% (95% CI 35.1% to 63.2%) sensitive and 74.3% (95% CI 64.8% to 82.3%) specific for 28-day mortality.

CONCLUSION

These results demonstrate the efficacy of the abbreviated MEDS score, the MEW score and NPT venous lactate levels in predicting 28-day mortality in ED patients with sepsis. The abbreviated MEDS score was found to be the best performing risk assessment model which, with prospective validation, may aid early clinical decision-making in ED patients with sepsis and might affect the outcome from sepsis.