Unexplained weight loss is common in chronic obstructive pulmonary disease (COPD). Blood levels of tumor necrosis factor-alpha (TNF-alpha), a cytokine causing cachexia in laboratory animals, are elevated in various human diseases associated with weight loss. We therefore prospectively measured TNF-alpha serum levels (immunoradiometric assay) in patients with clinically stable COPD (n = 30; all male; mean age, 65 yr) whose weight was less (Group I; n = 16) or more (Group II; n = 14) than the lower limit of normal taken from Metropolitan Life Insurance Company tables. The patients had no cause known to elevate TNF-alpha serum levels; notably, they were not infected. Group I patients had unintentionally lost weight during the previous year, whereas the weight of Group II patients had not changed during the same period. The two groups had similar chronic airflow obstruction and arterial blood gas impairment; hyperinflation and reduction in diffusing capacity were more pronounced in Group I, but differences were not significant. TNF-alpha serum levels (pg/ml; mean [SD]) were significantly higher in Group I than in Group II (70.2 [100.0] versus 6.7 [6.4]; p < 0.001). Group II TNF-alpha serum levels did not differ significantly from those of healthy subjects (7.8 [3.9]), whereas those of Group I were significantly higher (p < 0.001). Because renal function was in the normal range, we conclude that increased TNF-alpha production--and not decreased TNF-alpha clearance--is a likely cause of weight loss in patients with COPD.

-Urban sewage production is increasing and its agronomical use as a fertiliser has been advocated. Considerable defiance is prevalent in consumers and among farmers on the use of such fertilisers due to unknown pathological or environmental risks. The aim of the present review was to consider which pathological risk is major. Cysticercosis due to Taenia saginata appears to be one of the major pathological threats when sewage sludge is used to fertilise cattle pastures in temperate areas. The situation is different in Africa (Taenia solium and T. saginata are both highly prevalent) and Asia (Taenia saginata-like are prevalent). The processing of sludge and the delay between its application onto a pasture and grazing are probably major risk factors. Little data are available on the influence of processing, delay between processing and the use of sludge on the pathogenic risk. Producers and consumers will be more confident on the use of sludge if objective data are gained on risk. Most of the cases of cysticercosis (North America, United-Kingdom, Germany or Denmark) are related to poor human hygiene or accidental overflooding of sewage plants onto pastures. The standard application of sludge on pastures is apparently at low risk. This low risk does not mean that surveillance should cease since outbreaks of cysticercosis have been reported. Future investigations should concentrate on the most sustainable means of reducing risk (length of storage before use, composting, other treatments).urban sludge / parasite / cysticercosis / cattle / human Résumé -L'utilisation des boues d'épuration urbaine sur les pâturages : le risque de cysticercose. La production de boues urbaines résiduaires est en augmentation. Leur emploi agronomique comme fertilisant a été proposé. Une méfiance profonde des consommateurs ou des exploitants agricoles quant à l'emploi des boues urbaines en tant que fertilisants est réelle, qu'il s'agisse de risque pathologique ou environnemental. Le but de cette synthèse est de déterminer quel est le risque pathologique majeur. L'infestation par Taenia saginata semble être le risque le plus important en relation avec l'application 575 Vet. Res. 33 (2002) (33) 2 47427774; e-mail: cabaret@tours.inra.fr de boues d'épandages sur les pâturages bovins dans les régions tempérées. La situation est différente en Afrique (Taenia solium et T. saginata sont tous les deux très prévalents) et en Asie (les Taenia ressemblant à T. saginata ont un spectre d'hôtes herbivores assez large). Les processus de fabrication des boues et le délai entre le dépôt sur pâture et l'accès à la pâture sont sans doute des facteurs essentiels du risque. De rares données sont disponibles quant au délai et au traitement pour ce qui concerne leur pouvoir pathogène. Elles devraient être développées afin d'améliorer la confiance entre producteurs et consommateurs, sur des bases objectives. Le risque lié à l'épandage est faible comme le montrent des études aux USA, en Grande-Bretagne, Allemagne ou Danemark. La principale cause de risqu...

Level IV, therapeutic study.

Transient re-oxygenation of humans suffering from chronic obstructive pulmonary disease (COPD) allows the assessment of the consequences of chronic hypoxemia on peripheral muscle and metabolism apart from the effects of de-conditioning. The subjects performed maximal voluntary contractions (MVC) of flexor digitorum and vastus lateralis muscles and sustained infra-maximal contractions. COPD patients repeated the whole challenge during a 50-min oxygen breathing period and after recovery to baseline hypoxemia. We measured the compound evoked muscle mass action potential (M-wave) and the medium frequency (MF) of surface electromyography (EMG) power spectrum. Blood lactate (LA) and potassium (K+), erythrocyte-reduced glutathione (GSH), and plasma thiobarbituric acid reactive substances (TBARS) were also measured. Compared with a control group, COPD patients had lower MVCs, an attenuated decrease in MF during exercise, lower resting level of GSH, no posthandgrip TBARS increase and no GSH consumption. Reoxygenation (1) increased MVCs, (2) accentuated the MF decline and (3) elicited a posthandgrip TBARS increase and GSH consumption. Thus, we conclude that chronic hypoxemia exerts specific muscular effects: a reduced force production, an attenuated 'muscle wisdom', and the suppression of the exercise oxidative stress.