The MKK6/p38 stress kinase cascade is critical for tumor necrosis factor-alpha-induced expression of monocyte-chemoattractant protein-1 in endothelial cells

Monocyte chemoattractant protein-1 (MCP-1), a member of the C-C subfamily of chemokines, is important for the local recruitment of leukocytes to sites of inflammatory challenge. Here, we investigated endothelial signaling pathways involving members of the mitogen-activated protein (MAP) kinase superfamily and studied their role for MCP-1 expression in endothelium. We show that tumor necrosis factor-alpha (TNF-alpha), a potent inflammatory activator of endothelium, leads to activation of MAP kinases ERK, p38, and JNK in human umbilical vein endothelial cells (HUVEC). Contribution of MAP kinase pathways to TNF-alpha-induced synthesis of endothelial MCP-1 was then studied by pharmacologic inhibition and transient expression of dominant negative or constitutively active kinase mutants using flow cytometry, Northern blot, and luciferase reporter gene assays. Inhibition of Raf/MEK/ERK or SEK/JNK pathways had no significant effect on MCP-1 levels, whereas blocking the MKK6/p38 pathway by p38 inhibitors SB203580 or SB202190 or by a dominant negative mutant of MKK6, the upstream activator of p38, strongly inhibited TNF-alpha-induced expression of MCP-1. Consistent with that finding, expression of wild-type or constitutively active MKK6 significantly enhanced the effect of limiting TNF-alpha concentrations on MCP-1 synthesis. These data suggest a crucial role for the MKK6/p38 stress kinase cascade in TNF-alpha-mediated endothelial MCP-1 expression.

Distributions of distances in information strings

Distances between identical symbols in information strings (biological, language, computer programs (*.exe files) are described with a different precision with four distributions: exponential, Weibull, log-normal and negative binomial. The correlations are sometimes highly significant.

[Ultrasensitive TSH screening for detection of thyroid gland dysfunctions in women of a medical ambulatory care patient group]

This aim of the study was to identify the prevalence of unsuspected thyroid dysfunction in a female population attending a medical primary care unit (case-finding study). A TSH assay of the third generation was used as a screening test. The overall prevalence of unsuspected thyroid dysfunction in 1061 female patients was 2.5% (0.5% overt hyperthyroidism, 0.3% overt hypothyroidism, 0.5% subclinical hyperthyroidism, and 1.2% subclinical hypothyroidism). The prevalence of thyroid disease is clearly age dependent with 4.3% over the age of 40 and 5.9% for 50-60 year-olds. The ratio for females below 40 and over 40 was 10.75 (Odds ratio, p < 0.0001). We conclude from our study and from the literature that TSH screening as a case-finding strategy is indicated, and also seems cost-effective, in women over 40 years of age.

Community violence and inpatient assaults: neurobiological deficits

The goals of this study were to examine the relationship between community violence and inpatient assaults and to identify neurological and neuropsychological deficits underlying violent behavior. Thirty-three inpatients with a history of community violence were compared with 69 patients who did not have such a history. Inpatient assaults were recorded for 4 weeks; a neurological/neuropsychological battery was then administered. Patients without community violence were more likely to show transient or no violence while in the hospital. Patients with community violence performed more poorly on the Wisconsin Card Sorting Test and on psychomotor tasks, impairments that are consistent with frontal lobe dysfunction. Inpatient assaults were not associated with these neuropsychological impairments. They were related, however, to impairment on frontal motor programming tasks and a history of community violence.

[Annular erythema in childhood--a new eosinophilic dermatosis]

Annular erythema of infancy is a rare and little-known entity. Since its initial description by Peterson and Jarratt in 1981 only 4 further cases have been reported. We present the first case in the German literature. A 4-year-old boy developed non-itching erythematous papules on the trunk which evolved into annular and gyrate erythemas within weeks. The condition showed a relapsing course with disease-free intervals of several months duration. There were no general complaints. Laboratory investigations including detailed serological tests for infectious diseases were normal. Histopathology showed a striking eosinophilic inflammatory infiltrate predominantly in perivascular areas, without peripheral blood eosinophilia. The clinical differential diagnosis of annular erythema of infancy includes erythema annulare centrifugum, while microscopically one must exclude eosinophilic cellulitis (Wells' syndrome). The etiology is unknown and there is no effective therapy. In our case, as well as in all previously published cases, the disease resolved spontaneously. Therefore, it may be considered benign and self-limited.

Interleukin-13 selectively induces monocyte chemoattractant protein-1 synthesis and secretion by human endothelial cells. Involvement of IL-4R alpha and Stat6 phosphorylation

Chemokines secreted by endothelium have been demonstrated to promote leucocyte recruitment to sites of inflammation. In the present study we investigated the effect of the T lymphocyte-secreted cytokine interleukin (IL)-13 on endothelial expression of chemokines. Employing in situ hybridization and enzyme-linked immunosorbent assay (ELISA) techniques we demonstrate that IL-13, which shares many of its activities with IL-4, selectively induces expression of the C-C chemokine monocyte chemoattractant protein (MCP)-1 in human umbilical vein endothelial cells (HUVEC). However, it fails to up-regulate other C-C and C-X-C chemokines potentially inducible in endothelium such as RANTES (regulated on activation, normal T expressed and secreted), gro-alpha, or IL-8. IL-13 dose-dependently induces monocyte chemotactic activity by HUVEC which can be efficiently blocked by neutralizing antisera against MCP-1. In contrast to the synergistic effect of IL-13 and tumour necrosis factor-alpha (TNF-alpha) on endothelial vascular cell adhesion molecule-1 (VCAM-1) surface expression, TNF-alpha-induced secretion of MCP-1 is not augmented by IL-13. Studying the signalling pathway activated by IL-13 it is demonstrated that a neutralizing monoclonal antibody (mAb) to the 140,000 MW component of the IL-4 receptor (IL-4R alpha) inhibits the effect of IL-13. Immunoprecipitation studies reveal that endothelial IL-4R alpha is rapidly tyrosine phosphorylated upon treatment with IL-13 and IL-4. We furthermore show that both cytokines activate the signal transducer and activator of transcription (Stat) protein-6 in endothelial cells. Our data suggest that IL-13 partly utilizes components of the IL-4 receptor signalling pathway for induction of endothelial MCP-1 expression to facilitate recruitment of blood leucocytes.

Minimally invasive coronary artery bypass techniques as adjunct to extracardiac procedures

BACKGROUND

Surgical management of coronary artery disease has improved dramatically over the last decades in terms of short- and long-term results. Nevertheless, elderly patients (more than 75 years); patients with reduced ejection fraction (less than 0.25), heavily calcified aorta, or coexisting noncardiac diseases; and patients requiring cardiac reoperation have an increased perioperative risk when operated on with cardiopulmonary bypass. Successful minimally invasive coronary artery bypass grafting without cardiopulmonary bypass has been reported in selected cases.

METHODS

In 8 of 40 high-risk patients undergoing operation on a beating heart, minimally invasive coronary bypass grafting was combined with vascular (carotid endarterectomy, n = 3; aortic replacement, n = 2) and abdominal procedures (a second look after combined pancreas and kidney transplantation) or defibrillator implantations (n = 2).

RESULTS

Postoperatively, there was no mortality, no morbidity, and no blood transfusion. Patients are free of symptoms at an average follow-up time of 5.5 +/- 5 months.

CONCLUSIONS

Our results indicate that minimally invasive coronary artery bypass grafting technique can be particularly useful if noncardiac procedures have to be performed in high-risk patients with significant coronary artery disease.

Serotonin in violent patients with schizophrenia

CSF levels of 5-hydroxyindolacetic acid (5-HIAA), the serotonin metabolite, were assayed in 10 violent and 10 matched nonviolent patients with schizophrenia. Mean group levels of 5-HIAA in cerebrospinal fluid were found to be nearly identical. Possible explanations, including effects of medications, are discussed.

Sclerosis of the skin in the GEMSS syndrome. An overproduction of normal collagen

BACKGROUND

We describe a recently observed set of autosomal dominant GEMSS (glaucoma, lens ectopia, microspherophakia, stiffness of the joints, and shortness) syndrome in a 47-year-old woman and her 23-year-old son. In addition, sclerosis of the skin, from which both patients suffered, is investigated in detail.

OBSERVATIONS

The histologic examination of skin biopsy specimens obtained from the upper aspects of the backs of both patients revealed a markedly thickened dermis. Immunohistochemical examination of the dermal collagen bundles showed a collagen pattern similar to systemic sclerosis and normal control skin. In situ hybridization showed a markedly enhanced gene expression of transforming growth factor beta 1.

CONCLUSION

The sclerotic skin changes in GEMSS syndrome are the result of an abnormally increased production of normal collagen that might be attributable to the enhanced in situ production of transforming growth factor beta 1.

Electron paramagnetic resonance studies of the methylmalonyl-CoA mutase reaction. Evidence for radical intermediates using natural and artificial substrates as well as the competitive inhibitor 3-carboxypropyl-CoA

The substrate-dependent homolysis of the cobalt-carbon bond and generation of organic radicals in the coenzyme-B12-methylmalonyl-CoA-mutase complex have been demonstrated by EPR measurements. Both the natural substrate methylmalonyl-CoA, its 13C-substituted analogue and the non-hydrolysable synthetic substrates succinyl-dethia(carba)-CoA, succinyl-dethia(dicarba)-CoA and 4-carboxy-2-oxo-butyl-CoA induced similar but not identical EPR signals. 3-Carboxypropyl-CoA, a novel competitive inhibitor, has been synthesised. Its Ki value of 89 +/- 6 microM was in the same range as the Km of succinyl-CoA. Using [5'-3H]adenosylcobalamin, an enzyme-dependent tritium transfer to the inhibitor has been shown. The enzyme-coenzyme-inhibitor complex also exhibited EPR signals that were less structured and less intensive than the corresponding signals with active substrates. These results prove that the inhibitor also induces cobalt-carbon bond homolysis and undergoes reversible hydrogen transfer but not rearrangement.

[Blunt and penetrating diaphragmatic injuries]

Between 1987 and 1992, 17 patients sustaining injury of the diaphragm were treated at our institution. All patients had associated injuries. Blunt diaphragmatic rupture (n = 13) was mostly diagnosed by chest X-ray, additional diagnostic procedures (contrast radiography, sonography) confirmed a suspected diaphragmatic rupture. In all 4 cases with penetrating injury the diagnosis was found by explorative laparotomy. In 2 patients sustaining blunt diaphragm rupture the diagnosis was delayed by 2 and 6 days. 3 patients (all sustaining blunt diaphragm rupture) died related to their associated injuries. All patients sustaining blunt or penetrating thoracoabdominal trauma, specially in high-velocity road accidents and injuries by shots or knives, are suspicious for diaphragmatic injury.

Resistance of mice to experimental leishmaniasis is associated with more rapid appearance of mature macrophages in vitro and in vivo

Resistance to murine leishmaniasis has been related to the propagation of specific Th cell subsets (Th1 and Th2). This study shows that there are differences between resistant and susceptible mice in the initial myelomonocytic infiltrate, which precede the specific T cell response. After subcutaneous injection of 2 x 10(7) Leishmania major into footpads of resistant C57Bl/6 and susceptible BALB/c mice we performed immunohistochemical studies on the infiltrate. Two days after infection the percentage of more mature, F4/80-positive macrophages in the lesion increased faster in C57Bl/6 mice (63%) than in BALB/c mice (29%). The same strain-specific differences were observed after infection of corresponding strains of athymic mice (57.2% in C57Bl/6 nu/nu; 33.6% in BALB/c nu/nu), thus excluding a T cell-controlled phenomenon. After 1 wk the infiltrate in susceptible mice began to reveal significantly more cells containing MRP14, which is expressed by granulocytes and less mature monocytes but not by mature macrophages. No corresponding differences were found between athymic strains, suggesting that at this point organization of the infiltrate falls under control of protective T cells. In bone marrow cultures of BALB/c and C57Bl/6 mice, the percentage of F4/80-positive macrophages was also increasing faster in C57Bl/6 mice than in BALB/c mice. Increased expression of the F4/80 Ag was associated with higher leishmanicidal activity of C57Bl/6 macrophages. MRP14-positive bone marrow cells on the other hand were rarely infected by parasites. We suggest 1) that the earlier appearance of leishmanicidal macrophages in lesions of C57Bl/6 mice could influence propagation of either Th1 or Th2 cells by reduction of parasite load or by differential secretion of decisive cytokines and 2) that the diffuse accumulation of granulocytes and inflammatory monocytes in susceptible mice facilitates spread of disease.

Resistance of mice to experimental leishmaniasis is associated with more rapid appearance of mature macrophages in vitro and in vivo

Resistance to murine leishmaniasis has been related to the propagation of specific Th cell subsets (Th1 and Th2). This study shows that there are differences between resistant and susceptible mice in the initial myelomonocytic infiltrate, which precede the specific T cell response. After subcutaneous injection of 2 x 10(7) Leishmania major into footpads of resistant C57Bl/6 and susceptible BALB/c mice we performed immunohistochemical studies on the infiltrate. Two days after infection the percentage of more mature, F4/80-positive macrophages in the lesion increased faster in C57Bl/6 mice (63%) than in BALB/c mice (29%). The same strain-specific differences were observed after infection of corresponding strains of athymic mice (57.2% in C57Bl/6 nu/nu; 33.6% in BALB/c nu/nu), thus excluding a T cell-controlled phenomenon. After 1 wk the infiltrate in susceptible mice began to reveal significantly more cells containing MRP14, which is expressed by granulocytes and less mature monocytes but not by mature macrophages. No corresponding differences were found between athymic strains, suggesting that at this point organization of the infiltrate falls under control of protective T cells. In bone marrow cultures of BALB/c and C57Bl/6 mice, the percentage of F4/80-positive macrophages was also increasing faster in C57Bl/6 mice than in BALB/c mice. Increased expression of the F4/80 Ag was associated with higher leishmanicidal activity of C57Bl/6 macrophages. MRP14-positive bone marrow cells on the other hand were rarely infected by parasites. We suggest 1) that the earlier appearance of leishmanicidal macrophages in lesions of C57Bl/6 mice could influence propagation of either Th1 or Th2 cells by reduction of parasite load or by differential secretion of decisive cytokines and 2) that the diffuse accumulation of granulocytes and inflammatory monocytes in susceptible mice facilitates spread of disease.

Technique of laparoscopic cholecystojejunostomy with a Roux-en-Y loop

In order to avoid laparotomy in patients with biliary obstruction due to inoperable carcinoma of the pancreatic head, we evaluated the feasibility of a bypass operation using minimal invasive measures. A technique of laparoscopic cholecystojejunostomy was tested in adult pigs who had undergone clip occlusion of the distal common bile duct to imitate choledochal obstruction. Complete biliary bypass was restored with a cholecystojejunostomy via a Roux-en-Y loop using two circular staplers (21, 25, or 29 mm diameter), introduced through a prototype 33-mm-diameter trocar, used to effect the proximal and distal anastomoses. Seven pigs operated on in this way recovered easily, with normal weight gain and without technical complications. Contrast radiography of the biliary bypass at autopsy on day 28 confirmed patent and leak-free anastomoses and functional bypass. We conclude that laparoscopic cholecystojejunostomy with a Roux-en-Y loop is a feasible technique and results in an uncomplicated postoperative course and a biliary bypass with optimal function. Endoscopic application of circular staplers for laparoscopic enterobiliary and enteroenteral anastomosis is practical and safe.

Long-term high-dose neuroleptic treatment: who gets it and why?

OBJECTIVE

High doses of neuroleptic medication are still administered to many patients, although many studies have shown the effectiveness of low-dose strategies. The purposes of the study were to determine whether and in what ways high-dose patients differed from patients on regular dosages and whether the higher dosages were more effective.

METHODS

In a case-control study at two large state hospitals, 38 high-dose patients were compared with 29 regular-dose patients.

RESULTS

The high-dose patients had a persistent course of illness, with severe chronic symptoms resulting in hospitalizations of much longer duration than those of the regular-dose patients. The high-dose patients evidenced more regressed functioning and were more violent. To control these behaviors, clinicians increased neuroleptic dosages.

CONCLUSIONS

The high-dose patients represented a subgroup of chronic regressed and violent patients. Clinicians prescribed high dosages and continued to use them despite a lack of clear evidence that such treatment is effective.

Expression of intercellular adhesion molecule-1 by murine macrophages is up-regulated during differentiation and inflammatory activation

Intercellular adhesion molecule-1 (ICAM-1, CD54) is a cell-surface glycoprotein which has been shown to play an important role for cell/cell interaction. Little is known about its occurrence in the murine monocyte/macrophage (M phi) lineage; hence, we analyzed ICAM-1 expression in cells and cell lines representing different stages of M phi maturation and studied its regulation during inflammatory activation. Flow cytometric analysis of bone marrow-derived M phi cultured in the presence of M-CSF, of thioglycollate-elicited peritoneal M phi and of M1 myeloblasts differentiated by lipopolysaccharide (LPS) treatment revealed that ICAM-1 is increasingly expressed during monocytic maturation. Accordingly, the myelomonocytic cell lines RMB.TG, WEHI.TG, J774A and P388D, which can be ordered in a linear differentiation sequence, showed increasing levels of ICAM-1 expression. Furthermore, ICAM-1 expression by bone marrow-derived M phi could be up-regulated by tumor necrosis factor-alpha, interferon-gamma and LPS. In two models of murine experimental inflammation, i.e. induction phase of contact hypersensitivity and cutaneous leishmaniasis, which are both dependent on M phi/T cell interaction, M phi expressing ICAM-1 were found to be highly abundant. In addition, it was demonstrated that co-culture of Leishmania maior parasites with bone marrow M phi led to up-regulation of ICAM-1 on these cells. In conclusion, our data clearly demonstrate that ICAM-1 is increasingly being expressed during maturation of murine M phi. Cytokines and inflammatory stimuli modulate M phi ICAM-1 expression as well thus referring to its considerable role during inflammation, e.g. providing accessory or costimulatory signals for T cell activation.

[Thrombopenia after liver transplantation]

Thrombocytopenia (TP) is a common finding after liver transplantation and is often multifactorially induced. In 31 of 33 liver transplant recipients (operated between 1986 and 1991 at our institution) TP was observed but only in 4 the nadir of the platelet count was less than 20,000/mm3. Highly significant influence in the severity of postoperative TP as well as on the recovery time (defined as the first day with a platelet count higher than 100,000/mm3) was found for a preexisting TP and for the intraoperative need for blood transfusions. 8/33 patients had a concomitant splenectomy but no effect on platelet nadir nor on the recovery time could be detected. In our series we could not find any platelet related factor with a significant impact on patient survival. In one patient severe TP was induced by a CMV-related hematophagic histiocytosis fully regredient with antiviral therapy. Another patient with AB0 incompatible graft had a severe TP induced by graft versus host disease.

[Evaluation of TSH suppression using a 3d-generation TSH assay: diagnostic and therapeutic consequences]

We measured basal and TRH-stimulated TSH values with a 3rd generation assay in patients under suppressive thyroxine (T4) therapy for thyroid carcinoma or goiter and in patients with overt hyperthyroidism. All hyperthyroid patients had undetectable basal TSH levels (< 0.01 mU/l). In patients on suppressive T4 treatment basal TSH values were undetectable in 37.5% (= group A) and measurable in the intermediate range of 0.01-0.05 mU/l in 62.5% (= group B). After TRH administration there was no TSH increase in the hyperthyroid patients (< 0.01 mU/l in 100%). T4-treated patients of group A showed no relevant TSH stimulation in 58% (peak < or = 0.05 mU/l = total TSH suppression). An increase of > 0.05 mU/l could be measured in 42% of group A and 100% of group B (= subtotal TSH suppression). Many of these TSH values measured by a 3rd generation assay are in the undetectable range for most of the commercially available 2nd generation assays (< 0.10 mU/l).

CONCLUSION

TSH assay of the 3rd generation decisively improves the diagnosis of hyperthyroidism and probably also borderline hyperthyroidism. Against the background of increased risk of osteoporosis and cardiac function disorders as a result of suppressive T4 treatment, our results suggest the following practical therapeutic guidelines: total TSH suppression with the risk of iatrogenic hyperthyroidism should be confined to high risk patients (eg with metastatic thyroid cancer). Where the risk is low, however (thyroid cancer with favourable prognosis, goiter, goiter prophylaxis), only subtotal TSH suppression is indicated.

Epidermal expression of the calcium binding surface antigen 27E10 in inflammatory skin diseases

The expression of the heterodimeric complex of the calcium-binding proteins MRP-8 and MRP-14 was investigated in various inflammatory dermatoses using immunohistochemical staining with the monoclonal antibody 27E10. In addition to the inflammatory infiltrate, a positive staining was repeatedly found in the involved epidermis from patients with lichen planus, lupus erythematosus and psoriasis vulgaris, but not in normal skin epidermis and/or in epidermis from leucocytoclastic vasculitis patients. The keratinocytic expression of the 27E10 antigen was dissimilar to that of the MHC class-II molecules and the adhesion molecule ICAM-1. These data indicate that the 27E10 antigen is a distinct activation marker of inflammatory keratinocytes and may have proinflammatory properties.

[Injuries of the cruciate ligament in children caused by sports accidents]

From 1982 to 1990, 87 knee arthroscopies were performed on children aged 13 years and younger, following post-traumatic haemarthrosis. Damage to anterior and posterior cruciate ligaments was found in more than 1/3 of these cases. The injury to the actual anterior cruciate ligament occurred more often than the injury associated with avulsion fracture of the tibial eminences. It was found that almost all of the ruptures to the actual anterior and posterior cruciate ligaments occurred proximally. Hence, if haemarthrosis occurs in children, arthroscopy should be performed as a diagnostic and therapeutic measure. Surgery must follow the complete rupture of the actual ligaments and dislocated fracture of the bony insertions. The outcome of these operations on children is very satisfactory.

[Does isolated TSH elevation need treatment? Study of risk factors for the development of manifest hypothyroidism]

Isolated elevations of basal TSH levels are frequently observed in the general population. In a prospective study we analyzed the spontaneous evolution of thyroid function over time in such patients. The mean observation period was 5.4 (0.5-12) years. During the follow-up period 20% of these patients developed overt hypothyroidism. The risk of developing hypothyroidism was determined primarily by the initial TSH value and an additive effect was found for the thyroid antibodies and the thyroidal reserve (delta-T3) after TRH stimulation (Cox proportional hazard model). The cumulative risk for overt hypothyroidism after 10 years was only 22% for a mean TSH level of 12 mU/l for patients with negative thyroid antibodies and a good thyroidal reserve (low-risk), but increased to 63% for patients with positive antibodies and impaired T3 reserve (high-risk). Therefore, patients with isolated elevation of TSH can be divided into two subgroups according to the results of TSH, antibody status and T3 reserve: (1) In the "low-risk group" with good prognostic factors the patients should be followed up by periodic laboratory testing only (TSH, FT4, every 2-3 years). (2) In the "high-risk group" with clearly abnormal parameters, however, frequent controls are mandatory (every 6-12 months) or treatment with thyroxine may be indicated.

[Typical nosocomial infection with an unusual cause: Hafnia alvei. Report of 2 cases and literature review]

The route of infection and the course of two typical nosocomial infections are described in two patients infected with a rare gram-negative bacterium. Both patients underwent cardiovascular surgery. They were placed close to each other in the intensive care unit for several days and suffered from pneumonia and from wound infection respectively. In both patients bacterial culture grew Hafnia alvei. Successful antibiotic treatment was achieved with Netilmicin and Imipenem. Urinary tract, respiratory tract and wound infections are the most frequent nosocomial infections according to the literature. Risk factors are duration of stay in the intensive care unit, shock, poor general condition and advanced age.

Insertion tendopathy in athletes. A light microscopic, histochemical and electron microscopic examination

Tendon tissue of eleven athletes suffering from insertion tendopathy and of two controls was examined. Part of the tissue was prepared for routine light microscopy, a part for enzyme histochemical staining of Nicotinamide-adenine-dinudeotide-diaphorase (NADP-diaphorase), lactate dehydrogenase (LDH), beta-glucuronidase and alkaline phosphatase. Small pieces of tissue were also prepared for electron microscopic examination. The removed tissue was edematous and mushy. The normally densely packed parallel or interwoven collagen bundles were loosened by edema, focal necrosis or hemorrhage. Infiltration of fatty tissue and granulation tissue was also present. The amount of acid mucopolysaccharides was markedly increased. The histochemical studies showed strong enzyme activity of NADP-diaphorase and LDH in normal tendon tissue as well as around areas of degeneration and in granulation tissue. beta-Glucuronidase and alkaline phosphatase was present, but in general with lesser activity than the above enzymes. The electron microscopic examination revealed marked degeneration of the fiber systems, focal necrosis, deposit of amorphous masses and mucopolysaccharides and focal mineralisation. The reparative zones showed proliferating capillaries, often with a collapsed lumen and prominent endothelial cells and basement membranes.

Studies on a highly active anticoagulant fraction of high molecular weight isolated from porcine sodium heparin

We have studied heparin fractionation using gel filtration and ion-exchange chromatographic methods. The starting material was commercial grade porcine mucosal sodium heparin (PSH). The fractionation was monitored employing synthetic substrates for assaying both antithrombin (with H-D-Phe-Pip-Arg-pNA ; S-2238) and anti-FXa (with Bz-Ileu-Glu-Gly-Arg-pNA ; S-2222) activities. The resulting fractions were evaluated in different amidolytic and coagulation methods used to determine heparin potency by comparison with PSH. By gel filtration of PSH on Ultrogel Aca 54, both strong anti-FXa and antithrombin activities were associated with the fractions eluted in the high molecular weight range (MW congruent to 20 x 10(3)). These fractions also had potent anticoagulant action when assayed by conventional clotting methods. PSH was also subjected to fractionation by an ion-exchange technique (DEAE-Sephacel) with increasing salt molarity. The patterns for antithrombin and anti-FXa activities were again closely related, if not identical. Four fractions were usually distinguished, with respectively negligible, intermediate, high and very high activities when compared to PSH. The very highly active fraction (HAF), approximately 15% by weight, was eluted at high salt molarity (greater than 0.8 M NaCl). On a weight basis its anticoagulant activity was congruent to 2-3 times that of PSH as determined by amidolytic as well as clotting methods. Intravenous injection of HAF to rabbits and dogs (1.0 and 2.5 mg/kg) produced a much stronger anticoagulant response than PSH, also showing an effect which persisted for a longer duration.