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Biomedical subjects

I Krause

Publications and source records attributed to I Krause.

At least 73 records · Page 4Linked to original sources
PubMed1994

Bovine seminal plasma aSFP: localization of disulfide bridges and detection of three different isoelectric forms.

Acidic seminal fluid protein (aSFP) is a major 13 kDa protein isolated from bull seminal plasma and characterized as a new growth factor which stimulates in vitro cell division and progesterone secretion by ovarian cells. Here, we establish that the four cysteines of oxidized aSFP form two disulfide bridges between nearest-neighbour residues. This pattern is conserved in boar spermadhesins, with which aSFP shares up to 50% amino acid sequence identity, and other proteins of the recently identified CUB domain family. Using isoelectric focusing in combination with sulfhydryl group-specific blotting, the three forms of aSFP were identified as completely oxidized (pI 4.7), partly reduced (pI 4.8) and fully reduced at pI 5.1. These results indicate that native aSFP possesses two pairs of cysteine residues of different reactivity. The observation that aSFP can protect sperm from oxidative damage might be explained by its reduction/oxidation behaviour.

Amino Acid Sequence↗
PubMed1993

The effect of aspirin on recurrent fetal loss in experimental antiphospholipid syndrome.

PURPOSE: To evaluate the effect of aspirin treatment upon fetal loss in mice with experimental antiphospholipid syndrome (APLS). MATERIALS AND METHODS: Experimental APLS was induced in pregnant mice by passive transfer of mouse monoclonal anticardiolipin antibody. The mice were treated with high (100 micrograms/d) or low (10 micrograms/d) dose of aspirin, using vitamin C (100 micrograms/d or 10 micrograms/d) as a control. The mice were assessed for the presence of lupus anticoagulants (prolonged aPTT), thrombocytopenia, degree of fetal resorption rate and mean embryo and placental weights. RESULTS: The mice with APLS had a higher fetal resorption rate (45.7 +/- 12.2% vs 2.5 +/- 0.4%, P < 0.001), reduced placenta mean weight (104 +/- 8 mg vs 169 +/- 7 mg, P < 0.001), prolonged aPTT (94 +/- 14 sec vs 39 +/- 4 sec, P < 0.001), and reduced mean platelet count (597 +/- 186 x 10(3)/mm3 vs 847 +/- 51 x 10(3)/mm3, P < 0.001). The group of mice with APLS, who were treated with low-dose aspirin, had a lower resorption rate (11.1 +/- 9.3% vs 45.7 +/- 12.2%, P < 0.001), a higher placenta mean weight (178 +/- 8 mg vs 104 +/- 8 mg, P < 0.001), a higher mean embryo weight (1042 +/- 134 mg vs 721 +/- 91 mg, P < 0.001), and a lower aPTT (58 +/- 15 sec vs 94 +/- 14 sec, P < 0.001). Mice who were treated with high-dose aspirin also had a lower resorption rate, although not as much as in the low-dose aspirin group (34.2 +/- 12.7% vs 45.7 +/- 12.2%, P < 0.001). CONCLUSION: Aspirin, especially in low dose, has a protective effect against obstetrical complications associated with experimental APLS.

Animals↗
PubMed1992

Erythromelalgia in a patient with thrombotic thrombocytopenic purpura.

Erythromelalgia is characterized by paroxysmal burning pain and redness of the distal extremities; primary and secondary forms exist. Secondary erythromelalgia is most commonly associated with essential thrombocythemia and polycythemia vera, and the pathogenic mechanism is thought to be platelet aggregation. Thrombotic thrombocytopenic purpura is characterized by thrombocytopenia, microangiopathic anemia, renal failure, and fluctuating neurologic signs and symptoms. The pathogenic mechanism suggested for thrombotic thrombocytopenic purpura is diffuse platelet aggregation. We describe a female patient in whom thrombotic thrombocytopenic purpura was associated with erythromelalgia. This has not been previously reported.

Aged↗
PubMed1992

Induction of experimental anti-phospholipid syndrome associated with SLE following immunization with human monoclonal pathogenic anti-DNA idiotype.

MIV-7 is a human monoclonal antibody that binds to DNA and carries a pathogenic anti-DNA idiotype 16/6. The antibody was generated by fusing peripheral blood lymphocytes of a healthy donor which were stimulated with an anti-idiotypic antibody to B11 (a human mAb anti-mouse mammary tumor virus-MMTV). The MIV-7, in addition to being an anti-DNA antibody, also binds to MMTV glycoproteins. Following immunization into the footpad of naive BALB/c mice with MIV-7, the mice developed anti-phospholipid syndrome (APLS) and SLE. The APLS was characterized by thrombocytopenia, the presence of anticardiolipin antibodies, lupus anticoagulant (prolonged APTT), high resorption rate of fetuses and lower mean weights of the placentae and fetuses. The SLE was characterized by serological markers (e.g. anti-DNA), laboratory (increased sedimentation rate and proteinuria) and histological findings (deposition of immune complexes in the glomeruli). Active immunization of mice with mouse monoclonal anti-cardiolipin antibodies led to the induction of primary APLS without SLE. The results add to our previous passive transfer model in which mouse monoclonal anti-cardiolipin antibody generated from immunized mice (CAM) was infused into the tail vein and also resulted in induction of pure APLS [11]. Our results demonstrate the ability to induce secondary APLS to SLE following immunization with a pathogenic idiotype of anti-DNA antibodies and to induce primary APLS with anti-cardiolipin mAb. The existence of these experimental models may permit controlled studies of novel therapeutic models.

Animals↗
PubMed1992

Diversity and pattern of inheritance of autoantibodies in families with multiple cases of systemic lupus erythematosus.

The pattern of inheritance of autoantibodies in eight families chosen from a pool of 110 families of patients with systemic lupus erythematosus (SLE) is described. In all the eight families at least two members were already affected by SLE. In total, 19 patients and 43 first degree relatives were examined. The inheritance of a large set of antinuclear antibodies (for example, DNA, Sm, RNP, Ro, La, histones) and 16/6 idiotype seemed to be related to some unknown genetic factors but not related to HLA. The presence of numerous antinuclear autoantibodies in the serum of a subject was not necessarily associated with overt disease. The incidence of the 16/6 idiotype among patients and their relatives was low. It is not yet clear whether the 'autoantibody burden' is greater in families with multiple cases of SLE than in families with single cases.

Antibody Diversity↗
PubMed1992

Distribution of two common idiotypes of anticardiolipin antibodies in sera of patients with primary antiphospholipid syndrome, systemic lupus erythematosus and monoclonal gammopathies.

The frequency of two common idiotypes of anticardiolipin antibodies (aCL) was determined in sera from three groups of subjects, patients with systemic lupus erythematosus (SLE), with primary antiphospholipid syndrome (PAPS) and with monoclonal gammopathies (MG), as compared to normal population. The idiotype 1.10, which was derived from a patient with active SLE and antiphospholipid syndrome, was found more frequently among patients with PAPS (10.5%, 10.5% and 22.2% in MG, SLE and PAPS, respectively) than the idiotype H3, which was derived from a human hybridoma monoclonal aCL generated from a healthy subject immunized with tetanus and diphtheria. The latter idiotype was detected in 8.7%, 6.5% and 11.7% of patients with MG, SLE and PAPS, respectively. Incidental findings in this study include a high prevalence of aCL among patients with MG (23%) and a high prevalence of anti-dsDNA antibodies, detected only by a sensitive enzyme-linked immunosorbent assay, among patients with PAPS. Our results indicate that idiotypic diversity exists among aCL derived from different sources. Some of these cross-reactive idiotypes may be more pathogenic than others.

Adult↗
PubMed1991

24,25(OH)2D3 affects the calcemic effects of 1,25(OH)2D3 by mechanisms independent of intestinal calcium absorption.

To better define the interaction between 1,25(OH)2D3 and 24,25(OH)2D3 in different states of renal function, the fractional absorption of Ca45 (FCa45) and plasma calcium (PCa) were determined in rats with intact kidneys and in rats with reduced renal mass after 5/6 nephrectomy. The two series of experiments were performed in control animals, and in rats treated with: 1) 1,25(OH)2D3, 54 ng/rat/day, 2) 24,25(OH)2D3 in the same dose, and 3) 1,25 and 24,25(OH)2D3 in the same (and equal) doses. In all animals 1,25(OH)2D3 administration was associated with a significant increase in PCa and in FCa45. In rats with normal renal function, however, 24,25(OH)2D3 enhanced and in rats with reduced renal mass it suppressed the hypercalcemic effect of 1,25(OH)2D3. These variations in PCa were not associated with further alteration in FCa45 which was similar after 1,25(OH)2D3 and after combined 1,25 and 24,25(OH)2D3 in normal rats and in rats with chronic renal failure. FCa45 was found to be of the same magnitude in rats with normal renal function and in rats with reduced renal mass. These results confirm previous findings of normal intestinal absorption of Ca in mild to moderate renal failure. The above data suggest that 24,25(OH)2D3 used in an equivalent dose does not influence the intestinal effects of 1,25(OH)2D3. Therefore, the interaction of 1,25 with 24,25(OH)2D3 in rats with intact kidneys or with reduced renal mass occurs at extra-intestinal sites.

24,25-Dihydroxyvitamin D 3↗
PubMed1991

A simple test of intestinal absorption of calcium in rats.

We have developed a simple test of fractional calcium absorption in rats using oral 45Ca. The tracer was administered via a gastric tube, each animal receiving 0.15 microgram 45Ca with calcium glubionate as a carrier. Plasma radioactivity was determined at 30, 60, 90 and 120 min and expressed as percent dose in extracellular fluid. The fractional absorption of 45Ca was also expressed as 'area under the curve' (F45Ca) calculated by Simpson's approximation for each rat. The fractional absorption of calcium was determined in fasting and nonfasting fed animal subsets, each subset including control and rats treated with 1,25(OH)2D3. After 1,25(OH)2D3 administration, a significant increase in plasma calcium was seen in both fasting and fed animals. The fractional absorption of calcium was significantly higher in 1,25(OH)2D3-treated fasting as compared with control rats. In these animals, a positive correlation was found between F45Ca and plasma calcium. In contrast, in fed rats, the determined fractional absorption of calcium was similar in control and after 1,25(OH)2D3 administration. These results point to the use of orally administered 45Ca as a technically easy method for calcium absorption which can be used in most laboratories. In fasting animals it is sensitive enough for the evaluation of the effect of promoters of calcium absorption. The different findings in fed and fasting states may be related to the transmural processes which regulate the intestinal absorption of calcium.

Animals↗
PubMed1991

The frequency of a common anti-DNA antibody idiotype (16/6) in different populations of patients with systemic lupus erythematosus.

The 16/6 anti-DNA idiotype (id) is a pathogenic idiotype first identified on a human hybridoma antibody derived from a patient with systemic lupus erythematosus (SLE). The SA-1 anti-DNA, which antibody was established in a similar fashion from a patient with polymyositis, also carries the 16/6 id, although it has a greater reactivity with dsDNA. The presence of the 16/6 id as defined by anti-16/6 and anti-SA-1 was determined in 3 distinct populations of patients with SLE: 502 Mexicans, 98 English (including Caucasians, West Indians, Chinese, Asians) and 93 Israelis. A similar prevalence (around 20%) of the 2 idiotypes was found, with a significant overlap. The latter finding was supported by a significant correlation noted between the prevalence of the 2 idiotypes (r = 0.58 p less than 0.001). Despite the fact that 16/6 antibody is most probably encoded by a germline gene, thus being genetically determined, no distinction in the prevalence of the ids could be detected between completely different populations of patients with SLE. This finding may support the independent pathogenic role ascribed to the 16/6 id.

Antibodies, Antinuclear↗
PubMed1990

The influence of 24,25(OH)2D3 on the calcemic effect of 1,25(OH)2D in rats with chronic renal failure is parathyroid hormone dependent.

Previous studies from our laboratory have shown that 24,25(OH)2D3 attenuates the calcemic effect of 1,25(OH)2D3 in rats with reduced renal mass. This study was undertaken to clarify the role of parathyroid hormone in this response. Adult rats (n = 27) with reduced renal mass after parathyroidectomy with an initial plasma calcium of 3.7 +/- 0.1 mEq/liter were divided into four groups: (i) control rats and rats treated with (ii) 24,25(OH)2D3, (iii) 1,25(OH)2D3, and (iv) both 1,25 and 24,25(OH)2D3. After 4 days significant hypercalcemia was seen in PTX animals receiving 1,25(OH)2D3 alone or in combination with 24,25(OH)2D3. Plasma calcium in the combined therapy rats (7.42 +/- 0.22 mEq/liter) was significantly higher than in those treated with 1,25(OH)2D3 alone (6.68 +/- 0.22 mEq/liter, P less than 0.05). After 8 days, plasma calcium was higher in the rats treated with 1,25(OH)2D3 but was of same magnitude in those treated with 1,25(OH)2D3 alone or in combination with 24,25(OH)2D3. In contrast, in a subset of rats (n = 35) with reduced renal mass but intact parathyroid glands similarly treated with the vitamin D metabolites, a blunted calcemic response was seen after the combination of 1,25(OH)2D3 with 25,25(OH)2D3 administration alone. These results show that in rats with reduced renal mass, 24,25(OH)2D3 attenuates the calcemic effect of 1,25(OH)2D3 only in the presence of intact parathyroid glands. The different calcemic responses to 1,25 or combined 1,25 and 24,25(OH)2D3 in intact or parathyroidectomized rats with chronic renal insufficiency may result from different interaction between the vitamin D metabolites and the parathyroid hormone, presumably at the level of bone.

24,25-Dihydroxyvitamin D 3↗
PubMed1990

Genetic variants of bovine beta-lactoglobulin. A novel wild-type beta-lactoglobulin W and its primary sequence.

A novel bovine beta-lactoglobulin W has been isolated and its complete primary structure is presented. It was isolated by chromatofocusing of a beta-lactoglobulin AW heterozygote and purified by recrystallization. During sequencing of the oxidized protein, it became evident that the new beta-lactoglobulin W is a subtype of variant B with a single difference at position 56. This Ile----Leu substitution, which means a shift of a methyl group from C-beta to C-gamma of the amino-acid side chain causes a change of pI of 0.007 units, which can be detected by high resolution electrophoresis. This Ile56 amino-acid residue is among the most conserved residues with the exception of kangaroo beta-LG. The structures of other bovine beta-lactoglobulins and their relationships are discussed.

Amino Acid Sequence↗
PubMed1988

Isoelectric focusing in immobilized pH gradients with carrier ampholytes added for high-resolution phenotyping of bovine beta-lactoglobulins: characterization of a new genetic variant.

The genetic variants of bovine beta-lactoglobulin (beta-lg) from the "Murnau-Werdenfelser" breed were analyzed in three different isoelectric focusing (IEF) systems. While carrier ampholyte IEF with a pH gradient of 0.2 pH/cm did not resolve the new variant W from the B variant and IEF in immobobilized pH gradients (IPG) with 0.1 pH/cm only partially resolved it, adequate separation was achieved with IPG-IEF in a pH 5.25-pH 5.7 gradient, in presence of 0.8 % w/v carrier ampholytes, both over a 10 and 17 cm separation distance. Apparent isoelectric points (pI's) and genetic frequencies (f) were as follows: beta-lg A, pI = 5.370, f = 0.364; beta-lg B, pI = 5.485, f = 0.480; beta-lg W, pI = 5.492, f = 0.076; and beta-lg D, pI = 5.610, f = 0.080. The small difference of delta pI = 0.007 between beta-lg B and beta-lg W respectively, seems to originate from a "silent" substitution of neutral amino acid residues as compared to the larger delta pI's of the other genetic variants of beta-lg, which result from substitution of charged amino acids.

Animals↗
PubMed1988

Characterization of proteins and fatty acid composition in Galapagos fur seal milk. Occurrence of whey and casein protein polymorphisms.

1. Milk proteins of the Galapagos fur seal (Arctocephalus galapagoensis) were separated adequately into whey and casein fractions using bovine milk analysis methods. 2. In samples from days 5-30 of lactation 40% of the total proteins were whey and 60% caseins; in mid-lactation, day 150, 25% were whey and 75% casein proteins. 3. Electrophoretic and isoelectric focusing patterns of fur seal whey protein differed widely from bovine patterns, whereas those of caseins were similar. 4. Polymorphisms of fur seal whey and casein proteins were noted and did not seem related to different stages of lactation. 5. C-16 and C-18 fatty acids contributed about 70% of fatty acids; 63% of the total acids in milk fat were unsaturated.

Animals↗