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Biomedical subjects

A Hofer

Publications and source records attributed to A Hofer.

80 records · Page 5Linked to original sources
PubMed1988

Isolation of fibrinogen A alpha-chain by affinity chromatography on concanavalin A-sepharose.

A method was developed for isolation of the A alpha-chain from S-carboxamidomethylated fibrinogen. A mixture of the three constituent polypeptide chains of human fibrinogen was applied onto a column of concanavalin A-Sepharose. While the carbohydrate-free A alpha-chain was not delayed on the affinity chromatography column, both glycosylated subunit chains, B beta- and gamma-chain, were adsorbed to the insolubilized lectin and were quantitatively eluted from the column with 0.2 M methyl-alpha-D-mannoside. SDS-electrophoresis on polyacrylamide gel was employed for analysis of chromatographic fractions. Complete recovery of the A alpha-chain was observed. The described procedure is very simple and permits isolation of large amounts of pure A alpha-chain from S-carboxyamidomethylated fibrinogen.

Chromatography, Affinity↗
PubMed1984

Hepatic disposal of biosynthetic human insulin and porcine C-peptide in humans.

To examine the fate of insulin across the liver bed, biosynthetic human insulin was infused in increasing amounts in six healthy men. Trapping of insulin by the liver was determined by means of the hepatic venous catheter technique. To minimize any possible error in the estimation of insulin removal as a result of endogenous insulin, pancreatic insulin secretion was suppressed by intravenous administration of somatostatin (500 micrograms/h). Infusion rates of human insulin were 30, 60, and 150 pmol/m2 X min (corresponding to 0.25, 0.5, and 1.25 U/m2 X h) for 70 minutes each. Steady-state insulin levels were within the physiologic range, ie, 69 +/- 2, 135 +/- 3, and 342 +/- 10 pmol/L, respectively. Euglycemia was maintained throughout the study by a variable glucose infusion. The output of C-peptide from the splanchnic bed was reduced by somatostatin by about 90%, indicating that endogenous insulin production only minimally contributed to total insulin levels achieved during infusion of exogenous human insulin. Fractional extraction of insulin by the liver (63 +/- 6%, 71 +/- 4%, and 74 +/- 5%) and hepatic insulin clearance (201 +/- 19, 235 +/- 23, and 245 +/- 29 mL/m2 X min) did not differ significantly during the three insulin infusion studies. The hepatic uptake of insulin rose with increasing insulin infusion rates, constituting 40% to 60% of total-body insulin removal. No change in the total metabolic clearance rate of insulin was observed between the groups (451 +/- 8 mL/m2 X min). To study the extraction rate of C-peptide by the liver, porcine C-peptide was also infused at the same increasing rates.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Genetic parameters of a random regression model for daily feed intake of performance tested French Landrace and Large White growing pigs.

Daily feed intake data of 1 279 French Landrace (FL, 1 039 boars and 240 castrates) and 2 417 Large White (LW, 2 032 boars and 385 castrates) growing pigs were recorded with electronic feed dispensers in three French central testing stations from 1992-1994. Male (35 to 95 kg live body weight) or castrated (100 kg live body weight) group housed, ad libitum fed pigs were performance tested. A quadratic polynomial in days on test with fixed regressions for sex and batch, random regressions for additive genetic, pen, litter and individual permanent environmental effects was used, with two different models for the residual variance: constant in model 1 and modelled with a quadratic polynomial depending on the day on test d(m) as follows in model 2: sigma(epsilon(m))(2) = exp (gamma(0) + gamma(1) d(m) + gamma(2) d(m)(2)). Variance components were estimated from weekly means of daily feed intake by means of a Bayesian analysis using Gibbs sampling. Posterior means of (co)variances were calculated using 800 000 samples from four chains (200 000 each). Heritability estimates of regression coefficients were 0.30 (FL model 1), 0.21 (FL model 2), 0.14 (LW1) and 0.14 (LW2) for the intercept, 0.04 (FL1), 0.04 (FL2), 0.11 (LW1) and 0.06 (LW2) for the linear, 0.03 (FL1), 0.04 (FL2) 0.11 (LW1) and 0.06 (LW2) for the quadratic term. Heritability estimates for weekly means of daily feed intake were the lowest in week 4 (FL1: 0.11, FL2: 0.11) and week 1 (LW1: 0.09, LW2: 0.10), and the highest in week 11 (FL1: 0.25, FL2: 0.24) and week 8 (LW1: 0.19, LW2: 0.18), respectively. Genetic eigenfunctions revealed that altering the shape of the feed intake curve by selection is difficult.

Analysis of Variance↗
PubMedDate not supplied

Long-term results in the treatment of vitiligo with oral khellin plus UVA.

This study was performed to assess the effectiveness and short-term and long-term safety of oral khellin plus UVA (KUVA) in patients with vitiligo. Twenty-eight patients (13 males and 15 females; mean age, 34 years; [age range, 15-51 years]) most with extensive generalized vitiligo of more than 6 months duration had received KUVA at sometime during a 14-year period. The response to treatment (i.e. repigmentation of depigmented areas) was rated retrospectively comparing photographs taken before and after therapy and correlation analysis revealed that it was statistically significantly linked to the number of KUVA treatments (r = 0.833, P = 0.001) and to total cumulative UVA dose (r = 0.840, P = 0.001). Of 17 patients who had continued therapy for longer than 3 months, 7 (41%) had a good response (i.e., more than 70% repigmentation of lesional skin) after a mean of 194 treatments (range, 69-386 treatments) and a mean cumulative UVA dose of 2,036 J/cm2 (range, 690-4,411 J/cm2), whereas lower response grades were observed in the patients with lower treatment numbers. The most common short-term side effect was mild nausea, occurring in 8 of 28 patients (29%), and mainly in the first week(s) of treatment. Follow-up assessment at a mean of 40 months (range, 4-110 months) after the end of KUVA therapy available in 23 of 28 patients revealed no skin cancers or actinic skin damage in any patient. These data indicate that KUVA seems to be safe as well as effective for vitiligo, provided treatment is administered long enough.

Adolescent↗