Plasma proteins in a standardised skin mini-erosion (II): effects of extraction pressure

Background  

A standardised suction technique has been used to sample plasma proteins in dermal interstitial fluid (IF) serially for 5 to 6 days from a suction-induced skin mini-erosion. Increased protein concentrations ascribed to inflammation have been shown from day 1 onward. In this study, we assessed the effect of two different extraction pressures on IF sample composition.     

Mechanisms of nasal hyper-reactivity

Hyper-reactivity to non-specific challenges has been considered a hallmark of asthma and is defined as an abnormal responsiveness of the bronchial airways to a variety of provocative agents. The mechanisms underlying hyper-reactivity in the upper and lower airways are not known. By using the nose to study the inflammatory response possible abnormalities can be investigated carefully and pathophysiology of specific airway hyper-reactivities can be better understood. Other factors than merely constriction of the bronchial smooth muscles can cause narrowing of the free lumen to airflow. Functionally different and very distinct mucosal end-organ reactivities may also be increased. If these reactivities can be well assessed, specific airway hyper-reactivity can be defined. In the present report, specific mucosal end-organ hyper-reactivites in the allergic nasal mucosa are presented. Certain widespread hypotheses, such as the role of the eosinophil and the “increased absorption permeability theory”, are disputed.     

Effect of ethanol on ascorbate release in the nucleus accumbens and striatum of freely moving rats.

An in vivo voltammetry technique was used to monitor the extracellular ascorbate (AA) concentration in the nucleus accumbens and striatum of unanesthetized, freely moving rats. A single injection of ethanol, 1.0 g/kg intraperitoneally (IP), induced a significant increase in extracellular AA concentration in both the nucleus accumbens and striatum. This effect was dose dependent within a dose range from 0.5-2.0 g/kg. 4-Methylpyrazole (50 mg/kg, IP), which inhibits alcoholdehydrogenase, could not prevent the increase in AA concentration, evoked by ethanol. Furthermore, systemic administration of acetaldehyde (20 mg/kg, IP), the main metabolite of ethanol, did not have any effect on the level of AA in the nucleus accumbens or striatum. These results show that ethanol can alter the brain extracellular AA levels and that this effect seems to be attributed to ethanol itself and not to acetaldehyde. Consequently, these results indicate that a role for AA in the action of ethanol in the brain should be considered.     

Passive smoking and lung cancer in Swedish women

The relation between passive smoking and lung cancer was examined by means of a case-control study in a cohort of 27,409 nonsmoking Swedish women identified from questionnaires mailed in 1961 and 1963. A total of 77 cases of primary carcinoma of the bronchus or lung were found in a follow-up of the cohort through 1980. A new questionnaire in 1984 provided information on smoking by study subjects and their spouses as well as on potential confounding factors. The study revealed a relative risk of 3.3, constituting a statistically significant increase (p less than 0.05) for squamous cell and small cell carcinomas in women married to smokers and a positive dose-response relation. No consistent effect could be seen for other histologic types, indicating that passive smoking is related primarily to those forms of lung cancer which show the highest relative risks in smokers.     

The relationship of low-back pain, work history, work environment, and stress. A retrospective cross-sectional study of 38- to 64-year-old women

The association between low-back pain (LBP) and different work factors was investigated in a retrospective cross-sectional study of a random sample of 1,760 38- to 64-year-old women. The life-time incidence of LBP was 66% and the prevalence was 35%. In a univariate analysis, eight work variables correlated to LBP viz. more forward bending, more lifting, more standing, more monotonous work, dissatisfaction with the work tasks, dissatisfaction with the work environment, a higher degree of worry, and fatigue at the end of the work day. In a covariate analysis, however, only the three psychological variables remained directly associated to LBP viz. dissatisfaction with the work environment, a higher degree of worry, and fatigue at the end of the work day.     

Synaptically evoked membrane potential oscillations induced by substance P in lamprey motor neurons.

Short-lasting application (10 min) of tachykinin neuropeptides evokes long-lasting (>24 h) modulation of N-methyl-D-aspartate (NMDA)-evoked locomotor network activity in the lamprey spinal cord. In this study, the net effects of the tachykinin substance P on the isolated spinal cord have been examined by recording from motor neurons in the absence of NMDA and ongoing network activity. Brief bath application of substance P (30 s to 2 min) induced irregular membrane potential oscillations in motor neurons. These oscillations consisted of depolarizing and hyperpolarizing phases and were associated with phasic ventral-root activity. The oscillations were blocked by the tachykinin antagonist spantide II. They were also blocked by tetrodotoxin (TTX), suggesting that they were not dependent on intrinsic membrane properties of the motor neurons but were synaptically mediated. Substance P could also have a direct effect, however, because a membrane potential depolarization persisted in the presence of TTX. Protein kinase agonists and antagonists were used to investigate the intracellular pathways through which substance P acted. The oscillations were blocked by the selective protein kinase C (PKC) antagonist chelerythrine. However, the TTX-resistant membrane potential depolarization was not significantly affected by blocking PKC. The protein kinase A and G antagonist H8 did not affect either the oscillations or the direct TTX-resistant membrane potential depolarization. The glutamate receptor antagonist kynurenic acid abolished the substance-P-evoked oscillations, suggesting that they were dependent on glutamate release. The oscillations were abolished or reduced by the AMPA/kainate receptor antagonist 6-cyano-7-nitroquinoxalene-2,3-dione but were only reduced by the NMDA receptor antagonist D-AP5. The oscillations were thus mediated by glutamatergic inputs with a greater dependence on non-NMDA receptors. Blocking glycinergic inputs with strychnine resulted in large depolarizing plateaus and bursts of spikes. The glutamatergic and glycinergic inputs underlying the oscillations are apparently evoked through direct and indirect excitatory effects on inhibitory and excitatory premotor interneurons. Substance P thus has a distributed excitatory effect in the spinal cord. While it can activate premotor networks, this activation alone is not able to evoke a coordinated behaviorally relevant motor output.     

A foodborne outbreak of group A streptococcal disease at a birthday party.

A severe foodborne outbreak of group A streptococcal disease (T28) affected 122/169 people (72%) who attended a church party or ate leftovers from the party. The median incubation time was 42 h. Muscular pain or weakness and fatigue usually preceded pharyngeal symptoms. Complications included otitis media with perforation, peritonsillitis requiring tonsillectomy, arthritis and pericarditis. A 45-year-old man died 36 h after he developed an influenza-like illness, and at necropsy there were histological signs of early streptococcal septicaemia. The strain produced erythrogenic exotoxins B and C. Streptococci were probably transmitted by sliced eggs on sandwiches. Laboratory experiments showed that there was an increment in viable count of streptococci with 6 logs after incubation in egg yolk for 24 h at room temperature. The unusually warm climate and flaws in food handling routines contributed to this large foodborne epidemic.