Induced sputum inflammatory mediator concentrations in chronic cough

Previous studies have shown evidence of airway inflammation in patients with chronic cough and have suggested that the cough may be due to release of tussive mediators and activation of afferent sensory nerve endings. We measured the concentration of various proinflammatory and tussive mediators in induced sputum supernatants from 20 patients with cough variant asthma or eosinophilic bronchitis, 20 patients with nonasthmatic chronic cough, 22 patients with idiopathic chronic cough, and 18 healthy control subjects. We measured histamine, cysteinyl-leukotrienes, prostanoids (prostaglandin D2 and prostaglandin E2), and interleukin-8 by enzyme immunoassay. The median sputum histamine concentrations were significantly higher in patients with idiopathic chronic cough (8.0 ng/ml) and cough variant asthma/eosinophilic bronchitis (10.2 ng/ml) than in normal subjects (2.6 ng/ml; 95% confidence interval of difference from idiopathic chronic cough, 0.8 to 25.8 [p = 0.009] and 95% confidence interval of difference from cough variant asthma/eosinophilic bronchitis, 1.1 to 20.1 [p = 0.01]). Median sputum prostaglandin D2 and prostaglandin E2 concentrations were significantly higher in all categories of chronic cough. Our findings support the view that there is release of inflammatory and tussive mediators in patients with chronic cough and suggest that there might be similarities in the mechanism of cough in a diverse range of conditions.     

Effectiveness of diclofenac versus paracetamol in knee osteoarthritis: a randomised controlled trial in primary care

Background

The effectiveness of diclofenac versus paracetamol in primary care patients with pain caused by knee osteoarthritis is unclear.

Aim

To assess the effectiveness of diclofenac compared with paracetamol over a period of 2, 4, and 12 weeks in patients with knee osteoarthritis.

Design and setting

Randomised controlled trial in general practice.

Method

There were 104 patients included in the study, they were aged ≥45 years consulting their GP with knee pain caused by knee osteoarthritis. Patients were randomly allocated to diclofenac (n = 52) or paracetamol (n = 52) for at least 2 weeks. Primary outcomes were daily knee pain severity, and knee pain and function measured with the Knee Injury and Osteoarthritis Outcome Score (KOOS).

Results

Over a period of 2- and 4-weeks follow-up, no significant difference in daily knee pain was found between the patient groups: estimated differences of 0.5 (95% CI = −0.2 to 1.3) and −0.2 (95% CI = −1.0 to 0.7), respectively. Over the 12-weeks follow-up, no significant differences were found between both groups for KOOS pain: estimated difference of −2.8 (95% CI = −10.7 to 5.1) and KOOS function of −2.7 (−10.6 to 5.0).

Conclusion

Over a period of 2- and 4-weeks follow-up no significant difference in daily measured knee pain severity was found between primary care patients with knee osteoarthritis taking paracetamol or diclofenac. Also, over a period of 12-weeks follow-up no significant differences were found regarding KOOS pain and KOOS function between both groups. Patients more frequently reported minor adverse events after taking diclofenac (64%) than paracetamol (46%).     

Adrenocorticotropin and cortisol responses to vasopressin during pregnancy.

CRH is secreted by the placenta into the maternal and fetal circulation during pregnancy in humans and non-human primates. ACTH and cortisol responses to exogenous CRH are blunted during pregnancy. In the present study we examined the pituitary-adrenal response to another corticotropin releasing factor, vasopressin. Studies were performed in chronically catheterized female baboons moving freely in their home cages; 13 studies were performed in 4 pregnant animals, and 8 studies were performed in 6 nonpregnant animals. Vasopressin was administered iv in 2 doses (0.3 and 3.0 U), and plasma samples were obtained for CRH, ACTH, and cortisol measurements. Results are expressed as the mean +/- SEM. Baseline plasma CRH was 240 +/- 20 pmol/L in the pregnant animals and unmeasurable (less than 20) in the nonpregnant animals. In the pregnant animals, ACTH concentrations rose from a baseline of 6.4 +/- 1.3 pmol/L to 10.1 +/- 0.4 after 0.3 U vasopressin and to 24.9 +/- 5.2 after 3.0 U vasopressin. In the nonpregnant animals, ACTH levels were 5.8 +/- 1.3 at baseline, 6.7 +/- 1.3 after the 0.3-U dose, and 14.6 +/- 2.4 after the 3.0-U dose. The peak ACTH response after each dose of vasopressin was higher in the pregnant animals than in the nonpregnant animals (P less than 0.05). The baseline cortisol level in the pregnant animals was 960 +/- 80 nmol/L and rose to 1370 +/- 110 and 1535 +/- 165 after the 2 doses of vasopressin, respectively. The baseline cortisol concentration in the nonpregnant animals was 910 +/- 86 nmol/L. The cortisol level was 990 +/- 75 after the 0.3-U vasopressin dose and 1380 +/- 140 after the 3.0-U dose. The peak cortisol response after the 0.3-U dose was significantly higher in the pregnant animals (P less than 0.02), while the peak cortisol responses after the 3.0-U dose were similar in the 2 groups of animals. In a single animal, vasopressin was administered sequentially at 4 gestational ages during pregnancy and then 2 times in the postpartum period. The ACTH response to vasopressin increased as pregnancy progressed and then decreased in the postpartum period. In summary, the ACTH and cortisol responses to 0.3 and 3.0 U vasopressin, iv, are enhanced during pregnancy in the baboon, although the responses to exogenous CRH are blunted during gestation. We conclude that the chronic placental CRH stimulation of the pituitary-adrenal axis during pregnancy leads to an enhanced response to vasopressin and a down-regulation of the response to exogenous CRH.     

Phospholipase A2 levels in acute chest syndrome of sickle cell disease

Acute chest syndrome (ACS) is associated with significant morbidity and is the leading cause of death in patients with sickle cell disease (SCD). Recent reports suggest that bone marrow fat embolism can be detected in many cases of severe ACS. Secretory phospholipase A2 (sPLA2) is an important inflammatory mediator and liberates free fatty acids, which are felt to be responsible for the acute lung injury of the fat embolism syndrome. We measured SPLA2 levels in 35 SCD patients during 20 admissions for ACS, 10 admissions for vaso-occlusive crisis, and during 12 clinic visits when patients were at the steady state. Eleven non-SCD patients with pneumonia were also evaluated. To determine if there was a relationship between sPLA2 and the severity of ACS we correlated SPLA2 levels with the clinical course of the patient. In comparison with normal controls (mean = 3.1 +/- 1.1 ng/mL), the non- SCD patients with pneumonia (mean = 68.6 +/- 82.9 ng/mL) and all three SCD patient groups had an elevation of SPLA2 (steady state mean = 10.0 +/- 8.4 ng/mL; vaso-occlusive crisis mean = 23.7 +/- 40.5 ng/mL; ACS mean = 336 +/- 209 ng/mL). In patients with ACS sPLA2 levels were 100- fold greater than normal control values, 35 times greater than values in SCD patients at baseline, and five times greater than non-SCD patients with pneumonia. The degree of SPLA2 elevation in ACS correlated with three different measures of clinical severity and, in patients followed sequentially, the rise in SPLA2 coincided with the onset of ACS. The dramatic elevation of SPLA2 in patients with ACS but not in patients with vaso-occlusive crisis or non-SCD patients with pneumonia and the correlation between levels of SPLA2 and clinical severity suggest a role for SPLA2 in the diagnosis and, perhaps, in the pathophysiology of patients with ACS.     

Dopaminergic regulation of alpha-melanocyte-stimulating hormone and N-acetyl-beta-endorphin secretion in the fetal lamb

alpha MSH is present in high concentrations in the intermediate lobe of the fetal pituitary and has been implicated as a regulator of fetal adrenal steroidogenesis and fetal growth. However, there are few data regarding alpha MSH levels in fetal plasma or the control of fetal alpha MSH secretion. We measured alpha MSH immunoactivity in the plasma of chronically catheterized fetal lambs (gestational age, 116-138 days), newborn lambs, and adult sheep both in the baseline state and after dopamine receptor blockade with metoclopramide. The effect of metoclopramide on the release of another proopiomelanocortin-derived peptide, N-acetyl-beta-endorphin (N-acetyl-beta EP), which is synthesized together with alpha MSH in the intermediate lobe, was also studied. Baseline fetal plasma alpha MSH was significantly greater than maternal alpha MSH [35.6 +/- 2.2 (+/- SEM) vs. 10.0 +/- 1.0 pg/ml]. In eight studies in five fetal lambs, alpha MSH rose to a peak level of 121 +/- 23 pg/ml 15 min after metoclopramide administration to the fetus. Simultaneous maternal alpha MSH levels did not change, suggesting that the alpha MSH in fetal plasma was of fetal pituitary origin. Gel filtration of pooled fetal plasma extracts revealed that the alpha MSH immunoactivity eluted in the same position as the alpha MSH standard. Metoclopramide caused the secretion of nearly equimolar amounts of alpha MSH and N-acetyl-beta EP into fetal plasma. In four fetal lambs, basal N-acetyl-beta EP levels of 156 +/- 34 pg/ml rose to 305 +/- 65 pg/ml 15 min after metoclopramide treatment. Metoclopramide also stimulated plasma alpha MSH in newborn and adult sheep. In six newborn lambs, alpha MSH rose from 45.2 +/- 13 to 211 +/- 38 pg/ml 15 min after metoclopramide treatment, whereas in four adult sheep, a basal alpha MSH level of 11.1 +/- 2.2 pg/ml rose to 20.1 +/- 2.7 pg/ml 15 min after metoclopramide. In addition, metoclopramide stimulated fetal and neonatal PRL secretion, but had no effect on plasma vasopressin concentrations or acid-base and blood gas values. These studies indicate that immunoreactive alpha MSH and N-acetyl-beta EP are secreted into ovine fetal plasma and that the secretion of these peptides in the fetus appears to be under tonic dopamine inhibition, as is the case in the adult sheep and newborn lamb.     

ADRB2, brain white matter integrity and cognitive ageing in the Lothian Birth Cohort 1936

The non-synonymous mutations arg16gly (rs1042713) and gln27glu (rs1042714) in the adrenergic β-2 receptor gene (ADRB2) have been associated with cognitive function and brain white matter integrity. The current study aimed to replicate these findings and expand them to a broader range of cognitive and brain phenotypes. The sample used is a community-dwelling group of older people, the Lothian Birth Cohort 1936. They had been assessed cognitively at age 11 years, and undertook further cognitive assessments and brain diffusion MRI tractography in older age. The sample size range for cognitive function variables was N = 686–765, and for neuroimaging variables was N = 488–587. Previously-reported findings with these genetic variants did not replicate in this cohort. Novel, nominally significant associations were observed; notably, the integrity of the left arcuate fasciculus mediated the association between rs1042714 and the Digit Symbol Coding test of information processing speed. No significant associations of cognitive and brain phenotypes with ADRB2 variants survived correction for false discovery rate. Previous findings may therefore have been subject to type 1 error. Further study into links between ADRB2, cognitive function and brain white matter integrity is required.     

Age-dependent neurological phenotypes in a mouse model of PRRT2-related diseases

Paroxysmal kinesigenic dyskinesia is an episodic movement disorder caused by dominant mutations in the proline-rich transmembrane protein PRRT2, with onset in childhood and typically with improvement or resolution by middle age. Mutations in the same gene may also cause benign infantile seizures, which begin in the first year of life and typically remit by the age of 2 years. Many details of PRRT2 function at the synapse, and the effects of mutations on neuronal excitability in the pathophysiology of epilepsy and dyskinesia, have emerged through the work of several groups over the last decade. However, the age dependence of the phenotypes has not been explored in detail in transgenic models. Here, we report our findings in heterozygous and homozygous Prrt2 knockout mice that recapitulate the age dependence of dyskinesia seen in the human disease. We show that Prrt2 deletion reduces the levels of synaptic proteins in a dose-dependent manner that is most pronounced at postnatal day 5 (P5), attenuates at P60, and disappears by P180. In a test for foot slippage while crossing a balance beam, transient loss of coordination was most pronounced at P60 and less prominent at age extremes. Slower traverse time was noted in homozygous knockout mice only, consistent with the ataxia seen in rare individuals with biallelic loss of function mutations in Prrt2. We thus identify three age-dependent phenotypic windows in the mouse model, which recapitulate the pattern seen in humans with PRRT2-related diseases.

     

Regulation of erythropoietin production in a human hepatoblastoma cell line

Production of immuno and biologically active erythropoietin was documented to occur in the human hepatoblastoma cell line HepG-2. The expression of the erythropoietin gene was further verified by Northern blot analysis using a single stranded RNA probe. In vitro studies showed that erythropoietin production by these cells was not stimulated by hypoxia or cobalt chloride, but was related to the proliferative activity of the cells in culture. In addition it was found that the secretion of erythropoietin was almost completely abrogated by tunicamycin, an inhibitor of N-linked glycosylation. This effect of tunicamycin was also observed in a permanently transfected cell line that secretes erythropoietin in large quantities.     

An alternative extrinsic pathway of human blood coagulation

To study the interrelationships of the major human coagulation pathways, factor X activation in normal and various deficient human plasmas was evaluated when clotting was triggered by dilute rabbit or human thromboplastin. Various dilutions of thromboplastin were added to plasma samples containing 3H-labeled factor X, and the time course of factor X activation was determined. At a 1/250 dilution of rabbit brain thromboplastin the rate of factor X activation in factor VIII or factor IX deficient plasma was only 10% of the activation rate seen for normal or factor XI deficient plasma. Reconstitution of the deficient plasmas with factors VIII or IX, respectively, restored normal factor X activation. Similar results were obtained when various dilutions of human thromboplastin replaced the rabbit thromboplastin. From these experiments, it is inferred that normal activation of factor X in plasma due to dilute thromboplastin requires factors VII, IX and VIII. An alternative extrinsic pathway that involves factors VII, IX, and VIII may be a major physiologic extrinsic pathway, and this pathway may help to explain the clinical observations of bleeding diatheses in patients deficient in factors IX or VIII.