Airborne endotoxin associated with particles of different sizes and affected by water content in handled straw

High exposures to endotoxin are observed in environments where organic materials are handled and lower exposures are found in e.g. indoor air. Inhaled endotoxin contributes significantly to the induction of airway inflammation and dysfunction. The size of an inhaled particle influences the deposition in the airways and the following health symptoms. The objective is to characterise the distribution of endotoxin on airborne particles of different sizes in straw storage halls with high exposure and in other environments with lower exposure levels to endotoxin. Furthermore we have studied the influence of water content of handled straw on the size distribution of endotoxin containing particles. Total, inhalable, thoracic and respirable endotoxin and particles have each been quantified in aerosols from boiler rooms and straw storage halls at 24 power plants, including 21 biofuel plants. Inhalable, thoracic and respirable endotoxin have been quantified in aerosols from offices and outdoor air. The endotoxin concentration was higher in airborne thoracic dust than in airborne ‘total dust’. The median respirable fraction in the straw storage halls, boiler rooms at biofuel plants, boiler rooms at conventional plants, offices and outdoors was respectively 42%, 9%, 19%, 24% and 34%. Thoracic endotoxin per number of thoracic particles was higher than respirable endotoxin per number of respirable particles at the biofuel plants. In straw storage halls the fraction of endotoxin of respirable size was highest on the days with lowest water content in the received straw. Furthermore the exposures to all endotoxin fractions were highest on days with the lowest water content in the received straw. In conclusion the highest exposures and concentrations of endotoxin occur or tend to occur from thoracic dust. A high variation in endotoxin concentrations and in fractions of respirable or thoracic size is found in the different working areas. This is important in the risk assessment and makes attempts to influence the endotoxin exposure a possibility. Water content in straw affected the concentration, exposure level and size distribution of airborne endotoxin.     

Therapeutic effects of fengabine, a new GABAergic agent, in depressed outpatients: a double-blind study versus clomipramine

The results of a double-blind clinical trial of fengabine vs clomipramine in depressed outpatients are reported. Fengabine, a new GABAergic agent, seems to be as effective as the reference drug, with a faster onset of action and a more marked effect on cognitive disturbances and retardation. The new drug is free of any significant anticholinergic or cardiovascular effect, and it is not sedative.     

Screening for functional disorders of the masticatory system among teenagers

This study evaluated the efficiency of a questionnaire as compared to a brief clinical examination for identification of clinically assessed craniomandibular disorder cases. 706 Danish children 14-16 yr old answered a self-administered questionnaire concerned with dysfunction symptoms and oral habits. In addition they were subjected to a clinical examination of signs of dysfunction from the masticatory system. Based on the present study a self-administered questionnaire for screening purposes used in an a priori healthy population of teenagers cannot be recommended. The answers to the questionnaire showed a low reproducibility and their ability to predict clinically assessed signs of dysfunction was inadequate. The most favorable combinations of single questions were calculated in order to optimize sensitivity, specificity, and predictive value of the questionnaire. A maximum of 65% of the clinically diseased subjects were identified by the questionnaire and only 41% of the test positive subjects had their subjective diagnoses confirmed at the clinical examination. The brief clinical screening procedure succeeded in identifying 92% of children with severely disturbed function. The subjects testing positively according to the brief clinical examination were children with either moderate or severe disturbances except for only one case. Based on a cost to benefit consideration a brief clinical examination is preferred to a self-administered questionnaire as a routine procedure for detection of craniomandibular disorders.     

A simple calf muscle ergometer for use in a standard whole-body MR scanner

A calf muscle ergometer, designed for use in a standard whole-body MR scanner, is described. The instrument allows isotonic or isometric calf muscle exercise over a continuous range of work loads from 0 to individual maximum work output. Work output may be recorded on a strip chart recorder. A sound encoding provides an effective guidance for the subject tested to accurately reproduce his performance in each contraction cycle at a given work load. The FID recording may be triggered from the ergometer at any point during the contraction cycle. Nonmetal materials are used for the instrument construction in order to eliminate potentially disturbing eddy currents. The force resistance of the ergometer is obtained by a combined hydraulic-pneumatic system, which is loaded by coupling to an outside source of compressed air equipped with a suitable pressure regulator. When varying the time of data sampling within a repeated 6-s contraction cycle it was found that the recorded Pi/PCr ratio remained essentially constant at low and moderate work loads. However, at work loads at or above 70% of individual Vmax a pronounced dependence of the time of sampling with the contraction cycle was observed.     

Diminished mitogen-induced calcium uptake by lymphocytes from Alzheimer patients

Recent studies demonstrate diminished calcium uptake by cultured skin fibroblasts from Alzheimer patients. To determine if altered calcium homeostasis is also present in tissue taken from Alzheimer patients, calcium homeostasis was assessed in mitogen-stimulated lymphocytes. Calcium uptake by lymphocytes from Alzheimer patients was 10%-15% lower (p less than 0.002) than that of lymphocytes from age-matched controls. However, neither superficially bound nor total calcium was altered by Alzheimer's disease. These small differences in uptake may reflect larger differences in cytosolic calcium, in later calcium-mediated events, or in the response of particular subsets of lymphocytes. Their biological significance remains to be determined.     

Correlation of brain levels of 9-amino-1,2,3,4-tetrahydroacridine (THA) with neurochemical and behavioral changes

9-Amino-1,2,3,4-tetrahydroacridine (THA) has been reported to cause improvement in patients with senile dementia of the Alzheimer's type. We have examined some effects of THA in vitro and in vivo to define its mechanism of action. In vitro, THA inhibits acetylcholinesterase (AChE) (IC50 = 223 nM) and blocks [3H]AFDX-116 (M2) and [3H]telenzepine (M1) binding (IC50 s of 1.5 and 9.1 microM respectively). In vivo levels of THA were 10-fold higher in brain than plasma following 3.2 mg/kg i.p., a dose which was found to be active in reversing amnesia induced by scopolamine assessed in T-maze tests in rats and passive avoidance tests in mice. Additionally, these brain concentrations were above the IC50 of THA for AChE inhibition. THA (5.6-17.8 mg/kg i.p.) also elevated acetylcholine levels in the rat CNS. THA-induced side effects were blocked by the central muscarinic antagonist, scopolamine, but not by the peripheral antagonists methscopolamine and glycopyrrolate, nor by nicotinic antagonists. We conclude that brain AChE inhibition by THA is sufficient to explain its purported therapeutic activity in Alzheimer's disease and that its favorable brain/plasma distribution in vivo may account for its central cholinergic action without inducing the severe peripheral cholinergic effects typically seen with other AChE inhibitors.     

从平贝母茎叶中分离的平贝啶甙的结构

本文报道自平贝母(Fritillaria ussuriensis Maxim)的地上茎叶中分得一种新的甾体生物碱甙,定名为平贝啶甙(pingbeidinoside),mp 242～243.2℃[a]_D²⁵+6.9°(c 0.145,MeOH)。经IR,MS,¹HNMR和¹³CNMR谱解析,推定其结构为3β,16α,20-三羟基-Δ⁵-22,26-缩亚胺胆甾烷-25-O-α-D-葡萄糖甙。     

Comparisons between CK-B and other clinical indicators of cardiac contusion following multiple trauma

The activity of creatine kinase (CK) and creatine kinase B(CK-B) was measured in 17 patients with injuries to multiple organ systems, including the chest. The patients were closely observed for clinical signs of disturbed cardiac function by means of serial ECG, continuous monitoring of cardiac rhythm, daily cardiac auscultation, serial chest roentgenography and monitoring of central hemodynamic parameters. No statistically significant difference in CK and CK-B activity was found between the group of patients with normal cardiac function and the group with disturbed cardiac function. The CK-B activity was markedly elevated, but CK-B activity relative to CK activity was normal in both groups during the first 7 days after the trauma. The authors conclude that the significance of these enzymes' serum activity, measured with the immunoinhibition method, is diagnostically doubtful not only as regards cardiac contusions, but also in other cardiopathy preceding or following major trauma.