The formation of Ca++-dependent complexes of platelet membrane glycoproteins IIb and IIIa in solution as determined by crossed immunoelectrophoresis

Triton X-100 soluble proteins from 125I-labeled human platelets were studied by crossed immunoelectrophoresis employing a multispecific rabbit antibody raised against whole normal platelets. Emphasis was placed upon an analysis of immunoprecipitates containing 125I-labeled major membrane glycoproteins, and in particular, a prominent immunoprecipitate containing a glycoprotein antigen (s) previously designated as protein 16. SDS-polyacrylamide gel electrophoresis of protein 16 precipitated by a monospecific alloantibody. IgG L . . . , confirmed the presence of both glycoproteins IIb and IIIa. 125I-IgG L . . . , at concentration below that capable of precipitating protein 16 by itself, bound specifically to the precipitate containing protein 16 produced by the multispecific rabbit antibody. No other precipitates formed by the rabbit antibody contained either glycoprotein IIb or IIIa. When platelet proteins, incubated with optimum concentrations of ethylenediamine tetraacetic acid (EDTA) or ethyleneglycol bis (B- aminoethylether) NN1-tetraacetic acid (EGTA), were electrophoresed against the rabbit antibody, previously unobserved immunoprecipitates that contained either free glycoprotein IIb or free glycoprotein IIIa were detected. Upon readdition of excess Ca++, but not Mg++, to the same protein samples, a single immunoprecipitate containing both glycoproteins was once again observed. It is thus demonstrated that glycoproteins IIb and IIIa can form Ca++-dependent complexes (protein 16) in Triton X-100 extracts of normal platelets. The potential significance of the reversible association of these glycoproteins to normal platelet function is discussed.     

Falls and other geriatric syndromes in Blantyre,Malawi: a community survey of older adults

Background

The prevalence of geriatric syndromes (falls, immobility, intellectual or memory impairment, and incontinence) is unknown in many resource-poor countries. With an aging population such knowledge is essential to develop national policies on the health and social needs of older people. The aim of this study was to provide a preliminary survey to explore the prevalence of falls and other geriatric syndromes and their association with known risk factors in people aged > 60 years in urban Blantyre, Malawi.

Methods

This was a cross-sectional, community survey of adults aged > 60 years. Subjects were recruited at home or in the waiting areas of chronic care clinics. They were interviewed to complete a questionnaire on age-associated syndromes and comorbid problems. The Abbreviated Mental Test (AMT) and Timed Up and Go (TUG) tests were carried out.

Results

Ninety-eight subjects were studied; 41% reported falling in the past 12 months, 33% of whom (13% of all subjects) were recurrent fallers. Twenty-five percent reported urine incontinence, 66% self-reported memory difficulties, and 11% had an AMT score < 7. A history of falling was significantly associated with urine incontinence (p=0.01), self-reported memory problems (p=0.004) and AMT score < 7 (p=0.02).

Conclusions

Geriatric syndromes, including falls, appear to be prevalent in older people in Blantyre, Malawi. Falling is associated with cognitive impairment and urinary incontinence. There is an urgent need for more understanding of geriatric problems in this setting to develop national policies on health and social needs of older people. It is likely that many of the contributory factors to falls would be amenable to multifactorial interventions similar to those found to be effective in developed countries.     

Rapid MR imaging with suspended respiration: clinical application in the liver

The authors demonstrate that it is possible to obtain highly T1-weighted images of the abdomen using a suspended respiration partial saturation (SRPS) method in a breath-holding interval. T2*-weighted images, which reflect tissue T2 as well as variations in the static magnetic field, can also be rapidly obtained. The authors studied five healthy subjects and 19 patients with a variety of liver abnormalities, including benign and malignant hepatic neoplasms, fatty liver infiltration, ascites, and hematoma. On T1-weighted multisection acquisitions, the entire liver can be screened for mass lesions in a single 20-second breath-holding interval. Phase-contrast SRPS images are sensitive to fatty infiltration of the liver. SRPS images are more sensitive to variations in magnetic susceptibility than spin-echo images are, which has been proved to be of value in the detection of hemorrhage. With continued pulse sequence development and clinical study, this method has the potential to become the method of choice for evaluation of the upper abdomen.