Polymorphisms of the prion protein gene coding region in born-after-the-reinforced-ban (BARB) bovine spongiform encephalopathy cattle in Great Britain.

Polymorphisms of the prion protein gene are associated with differing susceptibilities to transmissible spongiform encephalopathy diseases, as shown for variant Creutzfeldt-Jakob disease in humans and scrapie in sheep, but not yet in cattle. Imposition of control measures in the UK, including a reinforced ruminant feed ban in 1996, has led to a reduction in the incidence of bovine spongiform encephalopathy (BSE). BSE-affected cattle born after 1996 in Great Britain have been termed born-after-the-reinforced-ban (BARB) cases. In this study, the PrP gene coding region from 100 BARB BSE cases and 66 matched healthy-control cattle was sequenced to investigate whether this would reveal a genetic basis to their origin. Polymorphisms identified were not found to be associated with increased susceptibility to BSE in the BARB cases. Analysis of BARB cases grouped either by clinical status or by whether they formed an isolated or clustered case was also undertaken, but differences were not found to be significant.

Identification of a proteinase K resistant protein for use as an internal positive control marker in PrP Western blotting.

The routine use of an internal positive control (IPC) marker could prove useful in the diagnosis of transmissible spongiform encephalopathy (TSE) diseases, particularly in surveillance programmes where large numbers of negative results are reported. Detection of an endogenous IPC protein in a negative sample adds confidence to the correct sample processing throughout the analytical procedure and could avoid the reporting of false negative diagnoses. Proteinase K (PK) resistance is one of the key diagnostic determinants of the disease-associated form of PrP (PrP(Sc)), the only disease-specific macromolecule currently associated with TSE disease. Additional PK resistant proteins, endogenous to TSE-suspect diagnostic tissue samples, were therefore assessed for use as IPC markers in the Western blot diagnosis of BSE and scrapie. Results indicated that, whilst essentially maintaining a standard PrP extraction and detection protocol, a ferritin heavy chain sub-unit of approximately 22kDa, was consistently detected in all PK treated TSE positive and negative tissue samples tested. Its presence in a range of sample types, any of which could be submitted under BSE and scrapie surveillance programmes, confirmed it as a suitable protein for an IPC marker in PrP(Sc) Western blotting.

[Neurologic diseases in Niger]. / Les maladies neurologiques au Niger.

The authors report the results of a study realized at National Hospital of Niamey (Republic of Niger) from october 1981 to may 1986. Among 4820 patients living in Western Niger, 410 (8.5%) had neurological disorders. Out of 16 recognized syndromes 6 constitute 75.2%: comas, paraplegias, cranial nerves palsies, convulsions, hemiplegias and sciaticas. An etiological diagnosis is made in 269 patients. From 15 diseases 4 totalize 73.5%: there are medullar compressions, infections of the central nervous system (bacterial meningitis, cerebral malaria), cerebral vascular disturbances and metabolic encephalopathies. POTT's disease is the most common cause of medullar compression with paraplegia and arterial hypertension is a very important etiologic factor of cerebral vascular attack (42.2 and 44.4% respectively). Parkinsonian syndrome and multiple sclerosis seem rare. The diagnosis of cerebral tumor is very uncommon but this is in relation to the absence of autopsy and of recent investigation (scanner). No case of tuberculous meningitis is noted and this can't be explained by the authors in a major tuberculous endemic area.