Raised enzyme markers of chronic inflammation in asymptomatic farmers' lung.

Subclinical inflammatory activity may be one of the factors which influences the variable natural history of farmers' lung. Serum lysozyme (LYS) and angiotensin converting enzyme (ACE) have been measured in 52 farmers with a previous history of farmers' lung and in 51 healthy control farmers. The group with farmers' lung assessed during the winter, although having had no recent acute symptoms, had significantly higher levels of LYS and ACE compared to both healthy control farmers seen in winter and farmers' lung subjects seen in summer. There was a mild but significant negative correlation between LYS and farm size in the farmers' lung subjects assessed in winter. The results suggest that active inflammation may be present in subjects with farmers' lung in the absence of acute symptoms during the season when dust exposure occurs as the result of feeding cattle.     

Prekallikrein-Kallikrein conversion rate as a predictor of contrast material catastrophies

An in vitro is described that attempts to detect patients with a potential for adverse systemic reactions to contrast material. This test involves measuring the rate of conversion of prekallikrein to kallikrein under certain standard conditions. In a preliminary retrospective study, the test could be used to identify such patients with a sensitivity of 88%, a specificity of 82%, and a predictive value of 79%.     

Cadherin-10 is a novel blood-brain barrier adhesion molecule in human and mouse

Maintenance of the specialised environment of the central nervous system requires barriers provided by the endothelium of brain microvessels (the blood-brain barrier (BBB)) or the epithelium lining the ventricles (CSF-brain barrier) or the choroid plexus (blood-CSF barrier). Inter-endothelial junctions are more extensive in the BBB than in other tissues, with elaborate tight junctions. However, few differences in the molecular composition of these junctions have been described. Here, we show, in both human and mouse brain, that the type II classical cadherin, cadherin-10, is expressed in BBB and retinal endothelia, but not in the leaky microvessels of brain circumventricular organs (CVO), or in those of non-CNS tissues. This expression pattern is distinct from, and reciprocal to, VE-cadherin, which is reduced or absent in tight cortical microvessels, but present in leaky CVO vessels. In CVO, the barrier function is switched from the microvasculature to the adjacent ventricular epithelium, which we also find to express cadherin-10. In the vessels of gliobastoma multiforme tumours, where BBB is lost, cadherin-10 is not detected. This demonstration of a distinctive expression pattern of cadherin-10 suggests that it has a pivotal role in the development and maintenance of brain barriers.     

Molecular characterization of Streptococcus pyogenes isolates collected during periods of increased acute rheumatic fever activity in Utah

BACKGROUND: Salt Lake City, Utah has seen a continuing resurgence of rheumatic fever (RF) since 1985. METHODS: emm genotyping and multilocus sequence typing of streptococcal isolates from periods of increased RF activity were performed. RESULTS: Multiple genotypes were present during 1985 and 1998, two peak years of RF activity, and in 1992, a year with reduced RF activity. emm3 and emm18.1 were present in 1985 and 1998, but not in 1992. Two other emm types, 12 and L28, were significantly elevated in 1998 (a peak RF year) over 1992 (a non-peak RF year). Allelic profiles for the emm3 and emm18.1 isolates exhibited clonality. CONCLUSIONS: During years of increased RF activity multiple emm types, including emm18.1 and emm3, were circulating in the community. During a year of decreased RF activity, emm3 and emm18.1 genotypes were absent. The clonality of the emm3 and emm18.1 types suggests that specific clones of both types are important in the resurgence of RF during these peak years. Two other genotypes, emm12 and emmL28, may also be associated with the persistence of RF in the Salt Lake City, UT area.     

Periorbital swelling: the important distinction between allergy and infection

Orbital cellulitis and abscess formation are rare complications of sinusitis, however acute orbital inflammation is secondary to sinusitis in about 70% of cases. Delay in diagnosis must not occur to avoid serious complications such as blindness and life threatening intracranial sepsis. A case is reported in which despite late referral, emergency surgical intervention was sight saving.     

Transient high altitude neurological dysfunction: an origin in the temporoparietal cortex

This case report describes three separate episodes of isolated ataxia, hallucinations of being accompanied by another person, and bilateral dressing apraxia occurring in a single individual without prior warning signs. These symptoms are attributable to disruption of vestibular processing in the temporoparietal cortex or associated limbic structures. Neurological dysfunction at high altitude is usually ascribed to high altitude cerebral edema or acute mountain sickness. However, transient neurological symptoms occur abruptly at more extreme altitudes, often following vigorous exertion, without overt altitude-induced prodromes. These symptoms may be caused by intense neuronal discharge or neuronal synchronization as a feature of epileptic discharges or cortical spreading depression. Transient high altitude neurological dysfunction should be recognized as a separate complication of extreme altitude, distinct from high altitude cerebral edema.