Lupus anticoagulant in the elderly may be associated with both quinine and quinidine usage.

Thirty-one patients aged over 60 yrs and with lupus anticoagulant (LA) were reviewed for their drug intake. Twenty-three (73%) were taking cinchona alkaloids, 10 (32%) quinine for night cramps, 11 (35%) quinidine for cardiac arrhythmia and 2 (6%) were taking both. These frequencies of drugs usage differed significantly from age and sex matched controls (p < 0.001). Five patients had features suggestive of the antiphospholipid syndrome. Repeat testing showed persistent LA activity in all but 2 of 5 patients in whom the relevant drug had been ceased. This is the first description of a possible causal association between LA and quinine therapy.

Asymptomatic swallowing disorders in elderly patients with Parkinson's disease: a description of findings on clinical examination and videofluoroscopy in sixteen patients.

We sought to ascertain whether patients with Parkinson's disease without symptoms of dysphagia have abnormalities of swallowing, and to describe the characteristics as seen on clinical examination and videofluoroscopy. Patients with stable Parkinson's disease were interviewed for symptoms of dysphagia and 16 asymptomatic patients were enrolled. Whilst on their usual medication, an examination of facial, tongue and palatopharyngeal musculature was made, and a modified barium swallow performed. All patients had at least one abnormality on videofluoroscopic examination of their swallowing. Three patients showed aspiration and 14 had evidence of vallecular residue considered a risk for aspiration. Oropharyngeal transit time was invariably prolonged as was delay in the initiation of swallow. The majority of patients also demonstrated an increased number of tongue elevations and number of swallows to clear their pharynx of the bolus. Despite having no symptoms of dysphagia, the patients demonstrated widespread abnormalities of swallowing.

High-resolution proton nuclear magnetic resonance spectroscopy of chloride peroxidase: identification of new forms of the enzyme.

Chloride peroxidase from the mold Caldariomyces fumago in the native high-spin iron(III) and low-spin cyanoiron (III) states has been subjected to high-field proton nuclear magnetic resonance spectroscopic measurements. Signals shifted well outside the diamagnetic envelope by the paramagnetic iron(III) center are surprisingly insensitive to pH changes over the range from pH 3 to pH 7. The previously identified major form of chloride peroxidase (form A) and the minor form (B) show very similar chemical shift patterns. Of greatest significance, however, is the discovery that each of the separable forms of the enzyme exhibits splitting of porphyrin ring methyl resonances. The appearance of two sets of signals in both native and cyanide-complexed enzyme is best explained by the existence of two additional forms of the A and B isoenzymes. Structural differences for the newly identified forms of chloride peroxidase must be located in the vicinity of the heme prosthetic group.