Relationship between plasma creatinine concentration and glomerular filtration in preterm newborn infants

Fluid management and dosage regimens of drugs in preterm infants should be based on the glomerular filtration rate. The current methods to determine glomerular flitration rate are invasive, time-consuming, and expensive. In contrast, creatinine clearance can be easy obtained and quickly determined. The purpose of this study was to compare plasma creatinine on the third and seventh day of life in preterm newborn infants, to evaluate the influence of maternal creatinine, and to demonstrate creatinine clearance can be used as a reliable indicator of glomerular filtration rate. We developed a prospective study (1994) including 40 preterm newborns (gestational age < 37 weeks), average = 34 weeks; birth weight (average) = 1840 g, in the first week of life. Inclusion criteria consisted of: absence of renal and urinary tract anomalies; O2 saturation 3 92%; adequate urine output (>1ml/kg/hr); normal blood pressure; absence of infections and no sympathomimetic amines in use. A blood sample was collected to determine plasma creatinine (enzymatic method) on the third and seventh day of life and creatinine clearance (CrCl) was obtained using the following equation: , k = 0.33 in preterm infant All plasma creatinine determinations showed normal values [third day: 0.78 mg/dl ± 0.24 (mean ± SD)and seventh day: 0.67 mg/dl ± 0.31 - (p>0.05)]. Also all creatinine clearance at third and seventh day of life were normal [third day: 19.5 ml/min ± 5.2 (mean ± SD) and seventh day: 23.8 ml/min ± 7.3 - (p>0,05)]. All preterm infants developed adequate renal function for their respective gestational age. In summary, our results indicate that, for clinical practice, the creatinine clearance, using newborn length, can be used to estimate glomerular filtration rate in preterm newborn infants.

Plasma levels of immunoinflammatory markers in De Novo coronary atherosclerosis and coronary restenosis postangioplasty

OBJECTIVE: To compare circulating plasma levels of immunoinflammatory markers in patients with known de novo coronary artery disease and patients with postangioplasty restenosis. METHODS: Using enzymatic immunoabsorbent assay, we measured plasma levels of soluble interleukin-2 receptosr, tumor necrosis factor alpha, and soluble tumor necrosis alpha receptors I and II in 11 patients with restenosis postcoronary angioplasty (restenosis group), in 10 patients with primary atherosclerosis (de novo group) who were referred for coronary angiography because of stable or unstable angina, and in 9 healthy volunteers (control group). Levels of soluble interleukin-2 receptors were significantly higher in the de novo group compared with that in the restenosis and control groups. Levels were also higher in the restenosis group compared with that in the control group. Plasma levels of tumor necrosis alpha and receptor levels were significantly higher in the de novo group compared to with that in the restenosis and control groups, but levels in the restenosis group were not different from that in the controls. CONCLUSION: Coronary artery disease, either primary or secondary to restenosis, is associated with significant immunoinflammatory activity, which can be assessed by examining the extent of circulating plasma levels of inflammatory markers. Moreover, patients with de novo lesions appear to have increased inflammatory activity compared with patients with restenosis.

Analysis of Plasma Homocysteine Levels in Patients with Unstable Angina

OBJECTIVE - To determine the prevalence of hyperhomocystinemia in patients with acute ischemic syndrome of the unstable angina type. METHODS - We prospectively studied 46 patients (24 females) with unstable angina and 46 control patients (19 males), paired by sex and age, blinded to the laboratory data. Details of diets, smoking habits, medication used, body mass index, and the presence of hypertension and diabetes were recorded, as were plasma lipid and glucose levels, C-reactive protein, and lipoperoxidation in all participants. Patients with renal disease were excluded. Plasma homocysteine was estimated using high-pressure liquid chromatography. RESULTS - Plasma homocysteine levels were significantly higher in the group of patients with unstable angina (12.7±6.7 µmol/L) than in the control group (8.7±4.4 µmol/L) (p<0.05). Among males, homocystinemia was higher in the group with unstable angina than in the control group, but this difference was not statistically significant (14.1±5.9 µmol/L versus 11.9±4.2 µmol/L). Among females, however, a statistically significant difference was observed between the 2 groups: 11.0±7.4 µmol/L versus 6.4±2.9 µmol/L (p<0.05) in the unstable angina and control groups, respectively. Approximately 24% of the patients had unstable angina at homocysteine levels above 15 µmol/L. CONCLUSION - High homocysteine levels seem to be a relevant prevalent factor in the population with unstable angina, particularly among females.

Influência de sexo e energia sobre a taxa de crescimento, eficiência de utilização alimentar, taxa de uréia (U) e de proteína iodada do plasma (PI) em gado de corte

Três rações, com nível alto, médio e baixo de energia - tratamento T1 , T2 T3 - foram ministradas em confinamento, à vontade, a bovinos recém-desmamados, machos inteiros, castrados e fêmeas, durante dois períodos de 17 semanas. Os machos inteiros exibiram a maior habilidade de ganho de peso, e as novilhas a menor habilidade. O tratamento T1 proporcionou os melhores ganhos e conversões, e o T2 os inferiores. Verificou-se pequena superioridade no teor protéico de T3, ao que se atribuiu sua vantagem sobre T2 no 1º período, e aparente crescimento compensatório no 2º período. O teor de uréia foi superior nos machos inteiros, e semelhante nos outros animais, superior em T3 e semelhante em T1 e T2, bem como aumentou consistentemente durante o experimento. Aparentemente a uréia refletiu o fornecimento adequado de proteína e, mais ainda, de energia. O teor de proteína-iodada não mostrou diferença significativa, mas apenas tendência de se elevar com o decorrer do tempo. Não houve correlação entre os dois componentes do sangue. Concluiu-se que a eficiência de utilização alimentar foi: superior nos machos inteiros, proporcional à quantidade de energia ingerida (no caso do 1º período); favorecida pelo teor maior de proteína de T3 em relação a T2 no 19 período, e talvez por ganho compensatório no 2º período; refletida pelos níveis de uréia no plasma, mas não correlacionado com proteína- iodada.

Lipoides do plasma normal

1. In a series of 21 normal cases we found for fatty acids per 100 cc. of plasma an average of 332 mgm., being 314 mgm. for the male sex and 350 mgm. for the female sex. 2.- For lecithin, in four normal cases we found per 100 cc. of plasma 182 mgm. estimated by the contents is phosphorus which ranged from 6.12 to 9.0 mgrs. 3.- Cholesterol in 20 normal cases showed 172 mgm. per 100 cc. of plasma. The averages were 151 mgm. for men and 194 mgm. for women. 4.- The readings of the fractions were 2.01 for the ratio fatty acids divided by lecithins 0.90 for lecithin divided by cholesterol and 1.93 for fatty acids divided by cholesterol. 5.- On comparing the results obtained by us with those reported in foreign literature an absolute conformity is noted chiefly with the values supplied by Bloor and Horiuchi for the ratios among the various lipoid fractions. The average for Cholesterol is comparable with that obtained by Myers but is slightly under that of Bloor's. The lecithin contents found by us did not reach such high values as those supplied by foreign authors.

Observaçães sôbre a congelação do plasma humano para desidratação

A technics for prefreezing of blood plasma and serum is described in this paper. The method indicated by Strumia et al. (2), uses a rapid local freezing to obtain the shell-freezing, with refigerated alcohol bath, at temperatures around minus 35ºC. On our work, it has been found that normal horse blood plasma fulfils the instructions given by Strumia, although normal human blood plasma, very often, fails to give the expected results. This is very disadvantageous at the routine work. With the use of small amounts of solid carbon dioxide, spread over the flasks, in the refrigerated bath, it has been possible to start the chrystallization. The technics prescribes a rapid cooling, like the one used by Strumia, to bring the temperature down, to about plus 10ºC. and, with rotating device stopped, the solid carbon dioxide is applied for one minute simultaneously on each flask. Starting rotation again, it begins to form a very uniform shell around the walls of the flasks.

Isolation of an enriched plasma membrame subpellicular microtubule fraction of Leishmania mexicana amazonensis

A cell fractionation procedure previously developed for Trypanosoma cruzi was applied to isolated the plasma membrane of promastigotes of Leishania mexicana amazonensis. The cell, swollen in an hypotonic mediun, were disrupted in the presence of a nonionic detergent and the membrane fraction isolated by differencial centrifugation. Electron microscopy showed that the fraction consisted of pieces of the plasma membrane associated with subpellicular microtubules. It was also shown that this fraction is able to induce cell-mediated immune response in mice.

Characterization of plasma menbrane polypeptides of trypanosoma from bats

Cell surface proteins of Trypanosoma dionisii, Trypanosoma vespertilionis and Trypanosoma sp. (M238) were radiodinated and their distribution both in the detergent-poor (DPP) and dertergent-enriched phase (DRP) was studied using a phase separation technique in Triton X-114 as well as polyacrylamide gel electrophoresis in sodium dodecyl sulphate (SDS-PAGE). Significant differences were observed in the proteins present in the DRP when the three species of trypanosoma were compared. Two major bands with 88 and 70 KDa were observed in T. sp. (M238) but were not detectable in T. dionisii and T. vespertilionis. Three polypeptides whith 96, 77 and 60 KDa were identified in the DRP of T. vespertilionis. Three major bands with 84, 72 and 60 KDa were observed in the DRP of T. dionisii. Two polypeptides with 34-36 KDa present in the DPP, were observed in the three Trypanosome species analyzed. Our observations show that T. sp. (M238) has characteristic surface polypeptides not found in T. vespertilionis.

An inhibition ELISA to determine alpha macroglobulin levels in mouse plasma

A sensitive method for quantifying mouse plasma alpha-macroglobulins (AM) using an inhibition ELISA is described. AM are important plasmaproteinase inhibitors that possibly act also as immunomodulatory molecules. The standard protocol develope in our experiments involves coating well with 10 µg/ml A2M in carbonate buffer, followed by incubation with a 1:1 (v/v) mixture of the plasma to be tested (diluted 1/1000) and goat anti-AM (diluted 1/1250). This is followed by further incubation, first with the enzyme-conjugated antibody and with the substrate prior to the reading of absorbance levels of the reaction products. Standard curve samples must be included in each plate, employing known amounts of the purified Murine Alpha-2-Macroglobulin (MuA2M) used for coating, with concentrations ranging from 0.001 to 10 µg/ml. Using test samples in triplicates and a 6-point standard curve in a single ELISA plate, 25 plasma samples can be tested accurately. The method offers an useful tool for establishing AM levelsin small samples of mouse plasma.