Low protein

About: Low protein is a research topic. Over the lifetime, 8139 publications have been published within this topic receiving 213225 citations.

A comparison of strategies to stabilize immunoglobulin Fv-fragments.

Abstract: Fv-Fragments of antibodies may dissociate at low protein concentrations and are too unstable for many applications at physiological temperatures. To stabilize Fv-fragments against dissociation, we have tested and compared three different strategies on the Fv-fragment of the well-characterized phosphocholine binding antibody McPC603 expressed and secreted in Escherichia coli: chemical cross-linking of the variable domains, introduction of an intermolecular disulfide bond, and construction of a peptide linker to produce a "single-chain" Fv-fragment. All the linked fragments show hapten affinities nearly identical with that of the whole antibody independent of protein concentration and are significantly (up to 60-fold) stabilized against irreversible thermal denaturation. All genetically engineered linked Fv-fragments can be obtained in native conformation in E. coli. The reported strategies for generating Fv-fragments with improved physicochemical properties may extend their usefulness in biotechnology as well as in therapeutic and diagnostic applications.

Mortality risk factors in patients treated by chronic hemodialysis. Report of the Diaphane collaborative study.

Abstract: A survival analysis was applied to 1,453 patients treated between 1972 and 1978 in 33 French dialysis centers and prospectively followed up in the computerized Diaphane Dialysis Registry. 198 deaths (overall mortality = OM) were registered, of which 87 (43%) were secondary to cardiovascular complications (cardiovascular mortality = CVM). Risk factors for OM and CVM (p values less than 0.05) were age, male sex, nephroangiosclerosis or diabetic nephropathy as the primary renal disease, elevated systolic and diastolic blood pressure and two weekly dialysis rather then three. In contrast with the results observed for the general population, a high body mass index and elevated cholesterol, triglycerides and uric acid were not found to be associated with significantly increased CVM or OM. On the contrary, low body mass index (less than 20 kg/m2), low cholesterol (less than 4.5 mmol/l) and low mean predialysis blood urea (less than 4.6 mmol/l) were associated with increased OM and CVM, and more especially with high stroke mortality. Results for urea but not for cholesterol remain significant after adjustment for age, sex, weekly dialysis schedule and body mass index. They suggest that, in addition to elevated blood pressure, a poor nutritional state and/or low protein intake may be important factors for explaining the high cardiovascular mortality, particularly for strokes, observed in dialyzed patients.

Effect of Dietary Protein on Bone Loss in Elderly Men and Women: The Framingham Osteoporosis Study†

Abstract: Few studies have evaluated protein intake and bone loss in elders. Excess protein may be associated with negative calcium balance, whereas low protein intake has been associated with fracture. We examined the relation between baseline dietary protein and subsequent 4-year change in bone mineral density (BMD) for 391 women and 224 men from the population-based Framingham Osteoporosis Study. BMD (g/cm2) was assessed in 1988-1989 and in 1992-1993 at the femur, spine, and radius. Usual dietary protein intake was determined using a semiquantitative food frequency questionnaire (FFQ) and expressed as percent of energy from protein intake. BMD loss over 4 years was regressed on percent protein intake, simultaneously adjusting for other baseline factors: age, weight, height, weight change, total energy intake, smoking, alcohol intake, caffeine, physical activity, calcium intake, and, for women, current estrogen use. Effects of animal protein on bone loss also were examined. Mean age at baseline (+/-SD) of 615 participants was 75 years (+/-4.4; range, 68-91 years). Mean protein intake was 68 g/day (+/-24.0; range, 14-175 g/day), and mean percent of energy from protein was 16% (+/-3.4; range, 7-30%). Proportional protein intakes were similar for men and women. Lower protein intake was significantly related to bone loss at femoral and spine sites (p < or = 0.04) with effects similar to 10 lb of weight. Persons in the lowest quartile of protein intake showed the greatest bone loss. Similar to the overall protein effect, lower percent animal protein also was significantly related to bone loss at femoral and spine BMD sites (all p < 0.01) but not the radial shaft (p = 0.23). Even after controlling for known confounders including weight loss, women and men with relatively lower protein intake had increased bone loss, suggesting that protein intake is important in maintaining bone or minimizing bone loss in elderly persons. Further, higher intake of animal protein does not appear to affect the skeleton adversely in this elderly population.