A fortifier comprising protein, vitamins, and calcium-glycerophosphate for preterm human milk.

BACKGROUND: The infant's own mother's milk, fortified with proteins, minerals, and vitamins, is considered the best food for low-birth-weight infants. This paper describes the process to obtain a liquid human milk fortifier. METHODS: The fortifier comprises a protein concentrate, calcium, phosphate, and zinc salts, as well as vitamins A and D. A powdered whey protein extracted from bovine milk was concentrated from 31.5-76.8 g/100 g using repetitive dialysis. The protein concentrate was dissolved in a 0.2 M phosphate buffer pH 7.4 and mixed with calcium-glycerophosphate and calcium-gluconate, vitamins A and D, folic acid, and zinc. Each 10 mL of this liquid fortifier has 0.78 g protein, 53 mg calcium, 36 mg phosphate, and 0.93 mg zinc. RESULTS: Repetitive dialysis did not modify the protein structure as demonstrated by electrophoresis. A total of 95% of lactose content was discarded. Enriching human milk using this human milk fortifier increased the concentration per deciliter of all added nutrients; proteins increased from 1.68-2.35 g, calcium from 26-90 mg, and phosphorus, from 15-51 mg. CONCLUSIONS: A liquid human milk fortifier was successfully manufactured using a noncomplex procedure. An intake of 180-200 mL/kg/day of the fortified human milk by the premature infant would satisfy the infant's nutritional requirements and achieve expected growth and development.

Whey protein/casein ratio and nonprotein nitrogen in preterm human milk during the first 10 days postpartum.

BACKGROUND: This study was designed to describe the longitudinal changes in the casein and whey fractions and the total and nonprotein nitrogen contents of preterm human milk for the first 10 days postpartum. METHODS: Eleven mothers delivering at 30 to 34 weeks of gestation were studied, six throughout the first 10 days and five on the first postpartum day. Four milk samples were collected every day by expression of one breast with an electric breast pump. Casein and whey protein were separated from the defatted milk by isoelectric precipitation in calcium chloride and by subsequent ultracentrifugation. The milk nitrogen content was determined before and after acid precipitation. Whey protein and casein were characterized by electrophoresis in polyacrylamide gel. RESULTS: Total and protein nitrogen showed a sharp decrease during the first 3 postpartum days, whereas the nonprotein nitrogen did not change markedly (mean concentration, 0.58 mg.ml-1). Casein content expressed as nitrogen in preterm human milk was 0.35 mg.ml-1 between days 3 and 5 and 0.60 mg.ml-1 between days 6 and 10. The whey protein-casein ratio before day 2, was 100:0, at day 3, 86:14, at day 5, 76:24, and at day 10, 70:30. Three days after delivery, casein levels rose progressively, increasing markedly after day 6. CONCLUSIONS: These findings suggest that delivering before term affects neither casein production nor its chemical characteristics.

Alfacristalina humana: su extraccion,purificacion e identificacion. / Human alpha-crystalline: its extraction, purification and identification

Se sabe que la alfacristalina humana que se libera en la rotura accidental o quirurgica del cristalino es causa de alteraciones oculares subsecuentes; por lo tanto, es necesario extraer y purificar dicha proteina si se desean aplicar procedimientos inmunologicos de laboratorio que ayuden al diagnostico temprano de estas alteraciones. Aqui se comunican los resultados de aplicar precipitaciones salina e isoelectrica y filtracion en gel a la extraccion y la purificacion de la alfacristalina del cristalino humano de individuos jovenes y su identificacion por electroforesis en gel de poliacrilamida y en poliacrilamida y dodecilsulfato de sodio. Se demuestra que la separacion inicial de la alfacristalina por filtracion en gel es un procedimiento eficaz en la purificacion de esta proteina, la cual, con las caracteristicas aqui informadas, se considera util para la induccion de anticuerpos

Human pituitary hormones extraction.

In order to know the efficiency of the human pituitary hormone extraction method utilized in the laboratory, six batches of 100 pituitaries each, were collected in acetone. Its delipidization and the initial acid extraction (0.3 M KCl, pH 5.5) of the powder were performed in the presence of 0.1 per cent thioethanol and the extraction was completed with an alkaline solution (0.1 N NaOH + H2O, v/v, pH 10.5). Hields in weight of powder and protein concentration for each fraction were similar to those previously reported by Elrick. Characterization of fractions with disc-gel-electrophoresis demonstrated a reproducible pattern for GH, and some differences among the samples containing the glycoproteins. The hormonal activities determined by radioimmunoassay showed a low contamination of GH in the fractions rich in glycoproteins, but these latter were similarly distributed between the acid and the alkaline extracts. The glycoprotein fraction had an important activity of TSH. The hormonal content per pituitary was calculated from the addition of activities in both extracts and the last residue; GH = 3 mg (4.494 IU); FSH = 761 micrograms (13.410 IU); LH = 782 micrograms (46.920 IU); TSH = 2.939 mg (9.350 IU). It is concluded that the technique is useful since there was a low GH contamination in the glycoprotein fraction and the TSH yield was important.

Polyacrylamide gel electrophoresis in human serum proteins in "normal" individuals and cancer patients.

The electrophoretic pattern of serum proteins of 100 "normal" adults and 97 non treated patients bearing different types of neoplasias were comparatively studied in polyacrylamide gel to find out if there are specific proteins or protein patterns in cancer. Densitometry was used to complete the study so as to analyze quantitative differences for each one of the regions of the arbitrarily divided electrophoregram of both types of sera. Strictly standardized colorimetric technique was used to quantify total proteins. Protein nomenclature was taken from literature data. As an average we found more bands in the cancer bearing patients than in "normal" individuals that also showed greater colour affinity in proteins. In the different regions, the main feature of neoplasia case was the presence of fewer bands in the post albumin (PA) and alpha-beta (post-beta) zones and many in 7s-globulin region (7s-g) than those found in "normals". The most important changes in the electrophoretic pattern of cancer patient serum were: a) Decrease in prealbumin (Pa), albumin (Alb), some from the postalbumin region (PA) and transferrin (T); frequent absence of ceruloplasmin (Cer) and complement factor 3 (C3) in a reduced number of cases. b) Marked increase of one alpha 1 glycoprotein in the PA region, hemopexin, haptoglobins and alpha 2-macroglobulin. Densitometry was useful to improve data obtained from visual analysis of gels but it could not make a quantitative differentiation of changes observed in beta and 7s-g regions. There was no significant difference in total protein concentration. Advantages and limitations of this method are discussed and results obtained are analyzed.