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1.
Domest Anim Endocrinol ; 59: 75-80, 2017 04.
Article in English | MEDLINE | ID: mdl-28013044

ABSTRACT

During lactation, the main surge of oxytocin is induced by a suckling stimulus. Previous studies have shown that salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline), a dopamine-derived compound, stimulates both the synthesis and the release of oxytocin in lactating sheep. The objective of the present study was to verify the hypothesis that salsolinol is involved in the mechanism that generates the oxytocin surge that occurs during suckling. Thus, a structural analogue of salsolinol, 1-methyl-3,4-dihydroisoquinoline (1MeDIQ), known to antagonize some of its actions, was infused into the third ventricle of the brain of lactating sheep nursing their offspring. Serial 30-min infusion of 1MeDIQ (4 × 60 µg/60 µL) or vehicle were administered at 30-min interval from 10 AM to 2 PM. The experimental period in every ewe consisted of a nonsuckling period (10 AM-12 PM) and a suckling period (12 PM-2 PM). Blood samples were collected every 10 min, to measure plasma oxytocin concentration by RIA. In control sheep, oxytocin surges of high amplitude were observed during the suckling period. The oxytocin surges induced by suckling were significantly (P < 0.01) diminished in sheep receiving 1MeDIQ infusions as compared to those that received control infusions. However, no significant effect of 1MeDIQ was observed on basal oxytocin release, before suckling. Furthermore, oxytocin release, as measured by the area under the hormone response curve (AUC), was significantly decreased by the administration of 1MeDIQ during the suckling period. This study shows that elimination of the effect of salsolinol within the central nervous system of lactating sheep attenuates the oxytocin surge induced by suckling. Therefore, salsolinol may be an important factor in the oxytocin-stimulating pathway in lactating mammals.


Subject(s)
Isoquinolines/pharmacology , Oxytocin/metabolism , Sheep/physiology , Animals , Area Under Curve , Cross-Over Studies , Female , Isoquinolines/administration & dosage , Lactation , Oxytocin/blood , Up-Regulation
2.
Domest Anim Endocrinol ; 58: 97-103, 2017 01.
Article in English | MEDLINE | ID: mdl-27792889

ABSTRACT

This study tested the hypothesis that salsolinol, a derivative of dopamine, affects GnRH and LH secretion in lactating sheep. In the in vivo experiment, the structural analogue of salsolinol, 1-methyl-3,4-dihydroisoquinoline (1-MeDIQ), was infused into the infundibular nucleus-median eminence of sheep at the fifth wk of lactation to antagonize salsolinol's action. Simultaneously, cerebrospinal fluid from the third brain ventricle, to determine GnRH concentration, and plasma samples, to measure LH concentration, were collected. In the in vitro experiment, the anterior pituitary (AP) explants from weaned sheep were incubated in culture medium containing 2 doses of salsolinol, 20 and 100 µg/mL (S20 and S100, respectively). The concentration of LH in the collected media and relative expression of LHß subunit messenger RNA in the AP explants were determined. No significant difference was found in mean GnRH concentration in response to 1-MeDIQ infusion, but both mean plasma LH concentration and LH pulse frequency increased significantly (P < 0.001 and P < 0.05, respectively) compared with those in controls. Significantly higher LH concentrations occurred during the first (P < 0.001), second (P < 0.001), and fourth (P < 0.05) h of 1-MeDIQ infusion. In the in vitro study, both the S20 and S100 doses of salsolinol caused a significant decrease in the mean medium LH concentration compared with that in the control (P < 0.01 and P < 0.001, respectively). Salsolinol had no effect on the relative LHß subunit messenger RNA expression in the incubated tissue. In conclusion, salsolinol is a potential inhibitor of the secretory activity of the gonadotropic axis in lactating sheep, at least at the AP level. Although no significant changes in GnRH release were directly confirmed, an increase in the frequency of LH pulses does not allow to exclude the central action of salsolinol.


Subject(s)
Gonadotropin-Releasing Hormone/antagonists & inhibitors , Isoquinolines/administration & dosage , Lactation/physiology , Luteinizing Hormone/antagonists & inhibitors , Sheep/physiology , Animals , Arcuate Nucleus of Hypothalamus/drug effects , Culture Media, Conditioned/analysis , Female , Gene Expression , Gonadotropin-Releasing Hormone/cerebrospinal fluid , Gonadotropin-Releasing Hormone/metabolism , Isoquinolines/antagonists & inhibitors , Luteinizing Hormone/analysis , Luteinizing Hormone/blood , Luteinizing Hormone, beta Subunit/genetics , Median Eminence/drug effects , Pituitary Diseases/metabolism , RNA, Messenger/analysis , Tissue Culture Techniques
3.
J Neuroendocrinol ; 28(3): 12362, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26749292

ABSTRACT

Salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline) is a dopamine-derived compound present in the central nervous system and pituitary gland. Several previous studies on lactating sheep and rats have reported that salsolinol plays a crucial role in the regulation of prolactin secretion. The present study investigated the effects of salsolinol, which was infused into the third ventricle of the brain, on oxytocin expression and release in lactating sheep, 48 h after weaning of 8-week-old lambs. Serial 30-min infusions of salsolinol and vehicle were performed at 30-min intervals from 10.00 to 15.00 h. Blood samples were collected every 10 min. The supraoptic nucleus (SON), paraventricular nucleus (PVN) and posterior pituitary were collected immediately after the experiment. Expression levels of mRNAs for oxytocin and peptidylglycine α-amidating monooxygenase (PAM), the terminal enzyme in the oxytocin synthesis pathway, were measured using a real-time polymerase chain reaction. Oxytocin peptide content in the posterior pituitary was measured by an enzyme-linked immunosorbent assay, and plasma oxytocin concentration was measured by radioimmunoassay. Salsolinol treatment significantly up-regulated oxytocin and PAM gene expression in the SON (P < 0.01 and P < 0.05, respectively), PVN (P < 0.01 and P < 0.05, respectively) and posterior pituitary (P < 0.05 and P < 0.05, respectively). Oxytocin peptide content in the posterior pituitary and the area under the response curve of plasma oxytocin were significantly (P < 0.05 and P < 0.01, respectively) higher in salsolinol-treated sheep than in control animals. The present study shows for the first time that salsolinol stimulates oxytocin secretion during lactation in sheep.


Subject(s)
Isoquinolines/pharmacology , Lactation/drug effects , Oxytocin/genetics , Oxytocin/metabolism , Sheep , Animals , Female , Hypothalamus/drug effects , Hypothalamus/metabolism , Infusions, Intraventricular , Isoquinolines/administration & dosage , Lactation/genetics , Lactation/metabolism , Mixed Function Oxygenases/genetics , Mixed Function Oxygenases/metabolism , Multienzyme Complexes/genetics , Multienzyme Complexes/metabolism , Oxytocin/blood , Pituitary Gland/drug effects , Pituitary Gland/metabolism , Pregnancy , Sheep/genetics , Sheep/metabolism , Up-Regulation/drug effects , Up-Regulation/genetics
5.
Biomed Res Int ; 2015: 526464, 2015.
Article in English | MEDLINE | ID: mdl-26339621

ABSTRACT

The study was designed to determine the effect of proinflammatory cytokine, interleukin- (IL-) 1ß, on melatonin release and expression enzymes essential for this hormone synthesis: arylalkylamine-N-acetyltransferase (AA-NAT) and hydroxyindole-O-methyltransferase (HIOMT) in ovine pineal gland, taking into account the immune status of animals before sacrificing. Ewes were injected by lipopolysaccharide (LPS; 400 ng/kg) or saline, two hours after sunset during short day period (December). Animals were euthanized three hours after the injection. Next, the pineal glands were collected and divided into four explants. The explants were incubated with (1) medium 199 (control explants), (2) norepinephrine (NE; 10 µM), (3) IL-1ß (75 pg/mL), or (4) NE + IL-1ß. It was found that IL-1ß abolished (P < 0.05) NE-induced increase in melatonin release. Treatment with IL-1ß also reduced (P < 0.05) expression of AA-NAT enzyme compared to NE-treated explants. There was no effect of NE or IL-1ß treatment on gene expression of HIOMT; however, the pineal fragments isolated from LPS-treated animals were characterized by elevated (P < 0.05) expression of HIOMT mRNA and protein compared to the explants from saline-treated ewes. Our study proves that IL-1ß suppresses melatonin secretion and its action seems to be targeted on the reduction of pineal AA-NAT protein expression.


Subject(s)
Arylalkylamine N-Acetyltransferase/biosynthesis , Interleukin-1beta/administration & dosage , Melatonin/biosynthesis , Pineal Gland/metabolism , Acetylserotonin O-Methyltransferase/biosynthesis , Animals , Female , Gene Expression Regulation, Enzymologic/drug effects , Interleukin-1beta/metabolism , Male , Melatonin/metabolism , Norepinephrine/administration & dosage , Pineal Gland/drug effects , RNA, Messenger/biosynthesis , Sheep
6.
Pediatr Transplant ; 2(4): 299-304, 1998 Nov.
Article in English | MEDLINE | ID: mdl-10084733

ABSTRACT

Allogeneic bone marrow transplantation (BMT) from an HLA-matched sibling appears to improve survival and diminish some of the physiologic derangements seen in children with mucopolysaccharidosis (MPS)-I (Hurler Syndrome), an inherited metabolic storage disease resulting from the lack of alpha-L-iduronidase enzyme activity. Death is usually expected in the first decade of life. Unfortunately, most patients lack an HLA-matched sibling donor and alternative donors have been identified for transplant. This study reports on a five-year median follow-up (range: 985-2,355 days) in 11 Hurler Syndrome patients who underwent allogeneic BMT from partially mismatched related donors (PMRDs). The median age was 20 months (range: 11-44 months). The overall survival rate was 64% (95% CI 34-94%). The overall graft failure rate (36%) was higher than reported with matched sibling BMT. All patients with sustained engraftment experienced improvement in physical manifestations, such as corneal opacity, gum and tongue hypertrophy, hepatosplenomegaly and joint mobility. Skeletal abnormalities, such as dysostosis-multiplex, were stabilized but not reversed. Some patients have continued to show decline in neuropsychometric testing, while others appear to stabilize and one has demonstrated improvement. Until better methods for replacing enzyme activity are developed, BMT from a matched sibling of alternative donors can be considered a viable intervention for Hurler Syndrome patients to achieve partial improvement or stabilization from the deterioration caused by substrate storage, particularly in minimally affected patients early in life.


Subject(s)
Bone Marrow Transplantation/methods , Histocompatibility Testing/methods , Mucopolysaccharidosis I/therapy , Actuarial Analysis , Bone Marrow Transplantation/adverse effects , Child, Preschool , Follow-Up Studies , Graft Rejection/etiology , Graft vs Host Disease/etiology , Humans , Infant , Mucopolysaccharidosis I/mortality , Mucopolysaccharidosis I/physiopathology , Neuropsychological Tests , Survival Analysis , Survival Rate , Transplantation, Homologous , Treatment Outcome
7.
Bone Marrow Transplant ; 19(5): 421-7, 1997 Mar.
Article in English | MEDLINE | ID: mdl-9052906

ABSTRACT

The results of partially matched related donor (PMRD) marrow transplantation for 82 patients with leukemia are reported, including 45 who received two antigen disparate grafts. Following intensive radiochemotherapy, patients received grafts which were partially depleted of T cells by the monoclonal antibody T10B9 and complement. Actuarial probability of engraftment was 86% (95% CI = 78-93%). The median day to engraftment was similar among recipients of grafts disparate at one, two or three antigen loci. The incidence of severe (grades III and IV) acute graft-versus-host disease and extensive chronic graft-versus-host disease was 13% and 6%, respectively. The probability of disease-free survival for the entire cohort of patients is 31% at 3 years. Age < or = 30 years, early or intermediate stage disease and a graft disparate at one or two loci predicted longer disease-free survival in multivariant analysis. Moreover, 47% of patients receiving PMRD grafts disparate at two loci who had both these favorable pretransplant characteristics were alive and free of disease 3 years after transplantation. We believe that the utilization of PMRDs, especially those with two antigen disparate grafts, can extend allogeneic transplantation to additional leukemic patients lacking a histocompatible donor, with acceptable results.


Subject(s)
Bone Marrow Transplantation/immunology , Graft vs Host Disease/etiology , HLA Antigens/immunology , Histocompatibility , Leukemia/therapy , Tissue Donors , Transplantation, Homologous/immunology , Acute Disease , Adolescent , Adult , Bone Marrow Transplantation/adverse effects , Cause of Death , Child , Chronic Disease , Cohort Studies , Combined Modality Therapy , Disease-Free Survival , Female , Graft vs Host Disease/epidemiology , Humans , Incidence , Leukemia/drug therapy , Leukemia/mortality , Leukemia/radiotherapy , Life Tables , Male , Middle Aged , Myelodysplastic Syndromes/mortality , Myelodysplastic Syndromes/therapy , Retrospective Studies , Severity of Illness Index , Survival Analysis , Transplantation, Homologous/adverse effects , Treatment Outcome
8.
Psychiatr Pol ; 31(1): 55-69, 1997.
Article in Polish | MEDLINE | ID: mdl-9527656

ABSTRACT

Fifty schizophrenic in-patients (DSM-IV) were treated in an open study with zuclopenthixol acetate. Mental status, improvement and side-effects were measured before administration of the drug as well as after the 1st, 2nd and 3rd injection. Positive and negative symptoms were evaluated with the use of PANSS. 60% of patients received three injections. Usually the intervals between injections lasted 48 hours. The improvement after the 3rd injection of zuclopenthixol acetate was found in 80% of patients. All positive symptoms improved after the treatment (p < 0.001), among them excitement (54% reduction vs. baseline), hostility (49%) suspiciousness/persecution (45%). The study revealed that parallel to the decrease of positive symptoms, the severity of negative symptoms also decreased, in particular: difficulty in abstract thinking (28%) and stereotyped thinking (27%) (p < 0.001). Passive/apathetic social withdrawal and lack of spontaneity as well as flow of conversation only slightly improved (p < 0.05). 50% of patients experienced side-effects--usually extrapyramidal reactions.


Subject(s)
Antipsychotic Agents/therapeutic use , Clopenthixol/analogs & derivatives , Schizophrenia/drug therapy , Schizophrenic Psychology , Adult , Aged , Clopenthixol/administration & dosage , Clopenthixol/therapeutic use , Dose-Response Relationship, Drug , Female , Humans , Male , Middle Aged
9.
Bone Marrow Transplant ; 18(4): 747-53, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8899190

ABSTRACT

From 1987 to 1991, 26 patients with CML and a median age of 31 years received allogeneic BMT from a partially mismatched related donor (PMRD) who shared at least one haplotype with the recipient. Nine patients were in accelerated phase (AP), and 11 patients were in blast crisis (BC) at the time of BMT. Patients were mismatched either in graft-versus-host or host-versus-graft directions for one antigen in 3 patients, two antigens in 14 patients, and three antigens in 9 patients. All patients were prepared with a regimen consisting of total body irradiation, etoposide, cytosine arabinoside, cyclophosphamide and methylprednisolone. All marrows were treated ex vivo with T10B91.A-31, a monoclonal antibody directed toward the alpha beta heterodimer of the CD3 receptor, and rabbit complement. Additional GVHD prophylaxis included either the anti-CD5 immunoconjugate XomaZyme-H65, cyclosporine, or both in combination with methylprednisolone. Eight patients did not have sustained engraftment. The 100-day survival was 42%. The incidence of > or = grade II acute GVHD was 29%. The incidence of chronic GVHD was 50% and was limited in all cases. The median survival at 4 years for all 26 patients was 27%. Seven patients (CP 1, AP 3, BC 3) remain in hematologic remission 1297-2241+ days after transplantation. AlloBMT from a PMRD may be considered for patients with advanced CML who lack a matched sibling or unrelated donor.


Subject(s)
Bone Marrow Transplantation , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/therapy , Adolescent , Adult , Animals , Blast Crisis/mortality , Blast Crisis/therapy , Bone Marrow Purging , Bone Marrow Transplantation/adverse effects , Bone Marrow Transplantation/immunology , Female , Graft vs Host Disease/etiology , Graft vs Host Disease/prevention & control , HLA Antigens , Haplotypes , Humans , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/immunology , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/mortality , Leukemia, Myeloid, Accelerated Phase/mortality , Leukemia, Myeloid, Accelerated Phase/therapy , Male , Middle Aged , Rabbits , Retrospective Studies , Survival Rate , Time Factors , Tissue Donors , Transplantation Conditioning , Transplantation, Homologous
10.
Bone Marrow Transplant ; 17(6): 917-22, 1996 Jun.
Article in English | MEDLINE | ID: mdl-8807094

ABSTRACT

Allogeneic BMT provides the best treatment currently available for long-term disease-free survival in patients with recurrent ALL. Historically, partially matched related donors provided the opportunity for treatment to a greater number of patients than matched related donors at the expense of decreased overall survival. In this study we compare the results in recurrent ALL patients transplanted with either HLA identical sibling bone marrow or partially matched related bone marrow. Thirty-two patients with relapsed ALL received partially matched bone marrows from a relative with one to three HLA, A, B and Dr antigen mismatches. Bone marrow was partially T cell-depleted with murine T10B9.1A-31 moAb. Sixteen patients with relapsed ALL received HLA-matched sibling bone marrows. All partially matched patients received additional GVHD prophylaxis with methylprednisolone in addition to anti-CD5 immunotoxin and/or CYA. All matched patients in addition to methylprednisolone received MTX and/or CYA. We observed no difference in disease-free survival between patients transplanted with partially matched bone marrow (median follow-up 1252 days, range 778-2035 days) vs those transplanted with HLA-matched bone marrow (median follow-up 1472 days, range 1165-2800 days; P = 0.48). Median survival for all patients is 38% (95% CI 24-52%) at 6 years. Patients transplanted in remission had a significant increase in disease-free survival when compared to those in relapse (P = 0.007). Our data suggest that partially matched BMTs from related donors are a comparable alternative to fully matched transplants in patients with ALL.


Subject(s)
Bone Marrow Transplantation , Histocompatibility Testing , Precursor Cell Lymphoblastic Leukemia-Lymphoma/therapy , Adolescent , Adult , Child , Child, Preschool , Cohort Studies , Female , Graft vs Host Disease/etiology , Humans , Lymphocyte Depletion , Male , Middle Aged , Precursor Cell Lymphoblastic Leukemia-Lymphoma/mortality , Recurrence , Transplantation, Homologous
11.
Transplantation ; 61(5): 738-45, 1996 Mar 15.
Article in English | MEDLINE | ID: mdl-8607177

ABSTRACT

Most patients requiring allogeneic bone marrow transplantation (BMT) lack a human leukocyte antigen genotypically identical sibling and require an alternative donor. This carries an increased risk of graft failure and acute graft-versus-host disease (GVHD). We sought to overcome these problems with transplants by using grafts obtained from the most readily available source: the haploidentical, partially mismatched, related donor. This study of 40 patients used a novel approach combining in vitro and in vivo T cell depletion with T lymphocyte targeted monoclonal antibodies (mAb) and intensified conditioning therapy, including fractionated total body irradiation before etoposide, cytoside arabinoside, cyclophosphamide, and methylprednisolone. Grafts were treated with T10B9.1A-31 mAb, directed against the alpha-beta heterodimer of the T cell receptor, and rabbit complement. In vivo depletion was attempted with an anti-CD5 mAb-Ricin A-chain (H65-RTA) immunotoxin (IT). Study patients were compared with a historical control group of 17 patients not given H65-RTA. Rates of engraftment were not significantly different (93% vs. 100%, P=0.12), although patients receiving IT engrafted more rapidly. The incidence of > grade I GVHD was significantly lower in the study group (36% vs. 100%, P=0.0001), as well as for severe grade III-IV GVHD (19% vs. 92%, P=0.0001). Five-year survival tended to be improved in the study group (40% vs. 18%, P=0.21). Transplant from haploidentical family members is indicated for patients without a matched sibling in whom allogeneic BMT offers the best opportunity to achieve cure.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Bone Marrow Transplantation , Graft vs Host Disease/prevention & control , Immunotoxins/therapeutic use , Lymphocyte Depletion , Ricin/therapeutic use , Adolescent , Adult , Aged , Animals , Bone Marrow Transplantation/mortality , Child , Child, Preschool , Female , Haplotypes , Histocompatibility Testing , Humans , Male , Middle Aged , Rabbits
12.
Blood ; 74(7): 2426-32, 1989 Nov 15.
Article in English | MEDLINE | ID: mdl-2508795

ABSTRACT

Lupus anticoagulant (LA), an antibody against anionic phospholipid with anticoagulant laboratory manifestations, is paradoxically associated with a high incidence of thrombosis. In the present study we analyzed the phospholipid- and platelet-dependent degradation of factor Va following clotting in plasma from 15 consecutive patients with LA to provide evidence for a distinct procoagulant effect of the antibody. After clotting with 25 micrograms phospholipid/mL, all samples containing LA showed markedly decreased rates of factor Va degradation (k = 0.01 to 0.14 min-1 v 0.27 to 0.35 min-1 in controls). Also with higher phospholipid concentrations (up to 100 micrograms/mL), as well as in the presence of platelets (5 to 33 x 10(7)/mL), significantly less of the procoagulant activity disappeared per unit of time in samples with LA than in controls. Plasma with LA was to a variable extent capable of decreasing or abolishing factor Va inhibition in normal plasma. Most importantly, exogenous activated protein C failed to correct the ineffective factor Va destruction despite adequate protein S levels. These data suggest that LA prevents the formation of the complex essential for rapid proteolysis of factor Va both on phospholipid and on the platelet membrane, thereby compromising the catalytic function of activated protein C. Our findings offer a new opportunity for a more comprehensive evaluation of patients with antiphospholipid antibody in defining the pathogenesis of thrombosis in this clinical condition.


Subject(s)
Autoantibodies/immunology , Blood Coagulation Factors/immunology , Protein C/physiology , Blood Platelets/physiology , Catalysis , Factor Va/metabolism , Humans , Lupus Coagulation Inhibitor , Lupus Erythematosus, Systemic/immunology , Phospholipids/physiology
15.
Bone Marrow Transplant ; 3(6): 589-98, 1988 Nov.
Article in English | MEDLINE | ID: mdl-3063328

ABSTRACT

In an attempt to assess the usefulness of partial elimination of T lymphocytes from histocompatible donor bone marrow as a sole method of graft-versus-host disease prophylaxis in patients undergoing bone marrow transplantation, we compared in vitro and clinically the efficacy of two depletion protocols, each resulting in a different degree of T cell reduction. The protocols were based on complement-dependent T cell lysis induced either by one (T10B9) or two (T10B9 and T12A10) monoclonal antibodies, contributing respectively to 95% and 99% depletion of T cells defined functionally by limiting dilution analysis. Phenotypic analysis was unsuitable for detecting differences in the efficiency of the two depletion modalities due to very low numbers of residual OKT3-positive cells generally present. Of the 34 patients with advanced leukemias transplanted with marrow from HLA-matched sibling donors, 26 (ages 15-52) received two-antibody depleted grafts (group I) with subsequent incidence of severe acute graft-versus-host disease of 8% (in two of 24 engrafted). The T cell dose for two patients of this group whose grafts were directly evaluated by limiting dilution analysis was less than 2 x 10(5)/kg and presumably did not exceed 3.2 x 10(5)/kg for others, based on the depletion efficiency of the protocol estimated in additional small marrow samples. The remaining eight patients (ages 8-55) received one-antibody depleted grafts (group II) with 5-18 x 10(5) T cells/kg defined functionally in five grafts. Severe acute graft-versus-host disease (grade 3-4) developed in all seven engrafted subjects. Although with phenotypic analysis several grafts in this group revealed no residual T lymphocytes, they apparently carried doses of donor T cells not tolerable in a HLA-identical host unprotected by additional immunosuppression. Careful evaluation by functional T cell analysis should be considered in choosing a depletion protocol as a method for reducing the risk of graft-versus-host disease in allogeneic bone marrow transplantation.


Subject(s)
Bone Marrow Transplantation , Graft vs Host Disease/prevention & control , Lymphocyte Depletion , T-Lymphocytes/immunology , Adolescent , Adult , Female , Histocompatibility , Humans , Male , Middle Aged , Phenotype , Thymidine , Transplantation, Homologous
16.
J Lab Clin Med ; 109(1): 89-96, 1987 Jan.
Article in English | MEDLINE | ID: mdl-3794520

ABSTRACT

To test the hypothesis that binding to an endogenous heparin-like substance controls breakdown of antithrombin III (ATIII) in vivo, the metabolic behavior of a commercial ATIII concentrate was investigated in three normal volunteers and five subjects with hereditary ATIII deficiency. The concentrate, purified to homogeneity as evidenced by sodium dodecyl sulfate--gel electrophoresis, was a 2:1 mixture of functional ATIII with heparin cofactor activity and dysfunctional ATIII incapable of binding enzymes or heparin. Each subject received intravenously a dose of 75 U/kg of ATIII activity together with iodine 125-labeled tracer. Daily fractional catabolic rates calculated from the three-exponential disappearance curves of plasma radioactivity were similar in all investigated subjects and were within the range obtained in studies using functionally homogeneous tracer. Although all subjects had markedly increased ATIII levels after injection of the concentrate, the relative sizes of their ATIII distribution pools resembled those reported previously for people with normal ATIII concentration. There was, however, a noticeably faster disappearance from plasma of excess functional ATIII compared with that of ATIII antigen, with mean half-lives of 47.5 +/- 9 hours and 62.3 +/- 8 hours, respectively. Assuming that antigenic ATIII represented both functional inhibitor and dysfunctional ATIII incapable of binding heparin, these data are consistent with the supposition that interaction with endogenous heparin or a similar substance may regulate a catabolic pathway marking ATIII for destruction.


Subject(s)
Antithrombin III/metabolism , Adult , Antithrombin III/administration & dosage , Antithrombin III Deficiency , Female , Humans , Injections, Intravenous , Kinetics , Male , Metabolic Clearance Rate , Middle Aged
18.
Blood ; 65(1): 15-20, 1985 Jan.
Article in English | MEDLINE | ID: mdl-3838081

ABSTRACT

To confirm the pathogenesis and the genetic background of neonatal-onset purpura fulminans, two unrelated infants with this rare thrombotic syndrome and 47 of their asymptomatic relatives were studied. In both families, 27 subjects with hereditary partial deficiency of protein C, including both parents of each patient, were identified. The patient in whom it was possible to evaluate protein C directly showed no detectable levels of this plasma component. These findings confirm the linkage of neonatal purpura fulminans to a genetic trait with established mendelian transmission and strongly suggest that the syndrome is an expression of homozygosity for protein C deficiency. The dramatic clinical picture and the type of pathologic change that develops as a result of the lack of circulating protein C emphasize the vital role of this protein in protection from thrombin generation, mainly within the microvascular system. However, our data do not contribute to the evidence that partial familial protein C deficiency is associated with a major risk of venous thromboembolism.


Subject(s)
Glycoproteins/deficiency , Purpura/genetics , Blood Coagulation Factors/analysis , Blood Coagulation Factors/genetics , Blood Proteins/deficiency , Blood Proteins/genetics , Female , Genetic Carrier Screening , Glycoproteins/genetics , Humans , Infant, Newborn , Male , Pedigree , Protein C , Purpura/blood , Purpura/pathology
20.
Thromb Haemost ; 51(1): 27-31, 1984 Feb 28.
Article in English | MEDLINE | ID: mdl-6719385

ABSTRACT

Interaction of human antithrombin III (AT III) with human alpha-thrombin coupled to Sepharose 4B was investigated. Despite markedly reduced esterolytic, amidolytic and especially coagulant activity, more than 90% of immobilized thrombin formed stable complexes with purified AT III. Presence of high affinity heparin did not facilitate the inhibition to the degree seen in reactions conducted with soluble thrombin. Instead, heparin induced proteolysis of up to 66% of the inhibitor that remained in solution. This led to the isolation of a homogeneous protein fragment which migrated in SDS-gel electrophoresis as a band of 50,000 Mr, cross-reacted with antibodies to human AT III but showed no biologic activity nor sufficient affinity for heparin. Out of the three major inhibitors capable of binding soluble thrombin in human plasma, only AT III reacted with immobilized thrombin. However, Sepharose-coupled thrombin mixed with plasma in the presence of heparin produced outstanding quantities of residual immunoreactive AT III devoid of inhibitory activity. These data suggest that presence of high affinity heparin in the environment of thrombin attached to a solid support may dramatically decrease the efficiency of enzyme inhibition.


Subject(s)
Antithrombin III/metabolism , Enzymes, Immobilized/metabolism , Thrombin/metabolism , Heparin/pharmacology , Humans , Molecular Weight , Peptide Fragments/isolation & purification , Protease Inhibitors/pharmacology
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