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Biomedical subjects

J Gram

Publications and source records attributed to J Gram.

At least 91 records · Page 5Linked to original sources
PubMed1992

Increased fibrinolytic potential induced by gliclazide in type I and type II diabetic patients.

Despite the fact that the relationship between impaired diabetic control and the development of vascular complications now seems less controversial than before, we are still in a situation where interventions or strategies aimed at decreasing the complications of late diabetes have high priorities. It is believed that accelerated vascular disease in the diabetic population is caused by repeated intimal injury of the arteries, and there is also evidence that the accelerated vascular disease states cannot be attributed only to the hyperglycemic state. One factor of importance for delayed tissue repair and arteriosclerotic disease in diabetic patients might be a disordered endothelial cell-dependent fibrinolytic system. Here, we review the evidence of the relationship between increased fibrin deposition and defective fibrinolysis in diabetic patients, and, furthermore, we discuss the possible beneficial effects of an enhancement of endogenous endothelial cell-related fibrinolysis by sulphonylurea drugs.

Arteriosclerosis↗
PubMed1992

Implementation of a thermal biosensor in a process environment: on-line monitoring of penicillin V in production-scale fermentations.

The production of penicillin V was monitored in 0.5 m3 and 160 m3 bioreactors. The thermal biosensor was an enzyme thermistor modified for split-flow analysis. The heat signal generated in the enzyme column was corrected for any nonspecific heat with the use of an identical but inactive reference column. The on-line monitoring was performed in the fermentation pilot plant and in a fermentation plant of Novo Nordisk A/S. Immobilized beta-lactamase was used to monitor three consecutive 0.5 m3 penicillin fermentations. Broth samples were continuously filtered through a tangential flow filtration unit in a sterile external loop. The on-line penicillin V values were 10% higher than those obtained by off-line HPLC analysis. Alternatively a polypropylene filtration probe was inserted into a 160 m3 bioreactor and samples were withdrawn at 0.5 ml/min. The same experiments were repeated with purified and immobilized penicillin V acylase. The on-line penicillin V values obtained with this enzyme correlated very well with those from HPLC analysis. The on-line monitoring was controlled and analysed by a software program written in Labtech Notebook.

Biosensing Techniques↗
PubMed1992

Serum levels of fetal antigen 2 in hyperthyroidism and primary hyperparathyroidism.

Serum concentration of fetal antigen 2 (FA2) in patients with hyperthyroidism (n = 18) (median: 12.9 mAU/l; range: 3.2-22.4 mAU/l) was significantly (p < 0.002) higher than in age- and sex-matched healthy controls (median: 4.1 mAU FA2/l; range: 2.4-10.0 mAU FA2/l). Serum FA2 was positively correlated with thyroxine (T4) (Rs = 0.51; p < 0.05), triiodothyronine (T3) (Rs = 0.64; p < 0.01), bone-Gla protein (BGP) (Rs = 0.70; p < 0.01), total alkaline phosphatase (total-AP) (Rs = 0.62; p < 0.01), bone isoenzyme alkaline phosphatase (bone-AP) (Rs = 0.63; p < 0.01), N-terminal procollagen type III (PIIINP) (Rs = 0.65; p < 0.01) and urine OH-proline (OHP) (Rs = 0.79; p < 0.01). In patients with hyperparathyroidism the pretreatment levels of FA2 (n = 8) (median: 17.6 mAU/l; range: 5.2-35.0 mAU/l) were significantly (p < 0.001) higher than those of age- and sex-matched controls (median: 3.7 mAU FA2/l; range: 3.4-9.0 mAU/l). The pretreatment level of FA2 was positively correlated with the parathyroid hormone (PTH) (Rs = 0.80; p < 0.05). Following surgical treatment the serum concentrations of FA2, PTH, and BGP decreased compared to pretreatment levels and the fall in these three parameters revealed parallelism. These data indicate that serum FA2 can be used as a marker in the evaluation of metabolic bone diseases.

Adult↗
PubMed1991

Increased fibrinolytic potential induced by gliclazide in types I and II diabetic patients.

This study examined the effect of gliclazide on tissue-type plasminogen activator (t-PA)-related fibrinolysis in 23 Type I diabetic patients without residual beta-cell function and 17 Type II diabetic patients initially treated with tolbutamide. The Type I diabetic patients received gliclazide for a period of 6 months; the Type II diabetic patients were shifted from tolbutamide to gliclazide. In Type I diabetic patients, after 2-3 months of treatment with gliclazide, we observed a significant increase in plasma concentrations of total t-PA antigen that remained stable until discontinuation of the drug (p less than 0.0002), whereas the plasma concentrations of plasminogen activator inhibitor (PAI) did not change significantly during the study. Next, we investigated the possibility of gliclazide inducing t-PA-related fibrinolysis in a subset of Type II diabetics without detectable concentrations of t-PA during treatment with tolbutamide. The concentrations of active t-PA increased significantly 3 months after a change in treatment to gliclazide, and active t-PA again decreased in one patient to undetectable levels after 12 months with gliclazide. Moreover, the plasma concentrations of total t-PA antigen increased significantly (p less than 0.02) in this group of diabetic patients while PAI remained unchanged. The changes in t-PA-related fibrinolysis could not be related in either Type I or Type II diabetics to changes in metabolic state evaluated by blood glucose, HbA1c, cholesterol, triglycerides, or apolipoproteins A and B. We conclude that gliclazide has the potential to exert extrametabolic non-insulin-mediated effects on t-PA-related fibrinolysis in diabetic patients.

Adult↗
PubMed1991

Long-lasting depression of the factor XII-dependent fibrinolytic system in patients with myocardial infarction undergoing thrombolytic therapy with recombinant tissue-type plasminogen activator: a randomized placebo-controlled study.

In a randomized placebo-controlled study, seven patients with acute myocardial infarction allocated to intravenous treatment with 100 mg of recombinant tissue-type plasminogen activator (rt-PA) and seven patients allocated to placebo were studied during eight sampling periods before and after treatment. Seven patients with acute myocardial infarction treated intravenously with 1.5 million U of streptokinase were later studied during two sampling periods before and after treatment. The placebo group showed no significant deviations of endogenous factor XII-dependent fibrinolytic activity (p greater than 0.05). In the rt-PA group, this activity decreased significantly (p less than 0.001) after the infusion and remained depressed throughout the 1st 4 days. A significant decrease in activity (p less than 0.05) was also found in the streptokinase-treated patients. The depletion of factor XII-dependent fibrinolytic activity was not due to generation of inhibition or a depletion of factor XII, prekallikrein and plasminogen, but could be related to the proactivator of this system. It is concluded that rt-PA (and streptokinase) treatment in patients with acute myocardial infarction causes a prolonged depletion of factor XII-dependent fibrinolytic activity. This depression of endogenous fibrinolytic activity needs to be evaluated in relation to the enhanced risk of coronary reocclusion after thrombolytic therapy.

Depression, Chemical↗
PubMed1991

Elevated serum levels of creatine kinase BB in autosomal dominant osteopetrosis type II.

Serum levels of creatine kinase isoenzyme BB (CK-BB) were measured spectrophotometrically and by electrophoresis in 17 patients with autosomal dominant osteopetrosis (ADO) and compared with those of age- and sex-matched controls. Eight patients had ADO type 1 and nine patients had ADO type II. CK-BB was significantly increased (p less than 0.002) in type II but normal in type I compared with controls. This finding supports heterogeneity of ADO, and it may indicate a potential role for CK-BB as a marker of immature osteoclasts.

Adult↗
PubMed1991

Down-regulation of monocyte functions by treatment of healthy adults with 1 alpha,25 dihydroxyvitamin D3.

A number of in vitro studies suggest an immunoregulatory role of 1 alpha,25 Dihydroxyvitamin D3 (1,25-(OH)2D3). The hormone inhibits production of interleukin-2 and immunoglobulin, and it blocks lymphocyte proliferation. Diverse effects on monocyte functions have been reported. However, immunological effects of 1,25-(OH)2D3 have not been substantiated in vivo. Six healthy male volunteers, aged 28-45 yr, were treated orally with 1,25-(OH)2D3 (tabl. Rocaltrol), 1 microgram twice daily for 7 days. Blood and urine samples were collected before and 7 days after initiation of treatment. Blood mononuclear cells from individuals treated with 1,25-(OH)2D3 showed a significantly reduced production of both interleukin-1 alpha (45%) and tumor necrosis factor-alpha (58%) (both measured by ELISA). Interleukin-6, production, measured by the B9 cell assay, was reduced in five individuals (78%), and unchanged in one. There was no effect on the release of interleukin-1 beta. There was no measurable effect on interleukin-2, interferon gamma or immunoglobulin production, or on mitogen-induced proliferation of blood mononuclear cells. Serum-osteocalcin and urine excretion of calcium were increased to 131 and 173%, respectively. The serum-calcium and serum-phosphate levels were unchanged.

Administration, Oral↗
PubMed1991

Depression of factor XII-dependent fibrinolytic activity characterizes patients with early myocardial reinfarction after recombinant tissue-type plasminogen activator therapy.

Twenty patients with acute myocardial infarction treated with recombinant tissue-type plasminogen activator (rt-PA) had endogenous factor XII-dependent fibrinolytic activity levels measured throughout the hospital period and those levels were prospectively correlated with the incidence of recurrent myocardial infarction until 8 weeks after hospital discharge. Within the follow-up period, recurrent myocardial infarction was observed in 8 patients, whereas the remaining 12 patients showed no clinical evidence of recurrence. The patients in the reinfarction group were characterized by a more pronounced depletion of and sustained lower levels of factor XII-dependent fibrinolytic activity than were the patients with no reinfarction (p less than 0.05). The decrease in fibrinolytic activity during rt-PA therapy was significantly associated with a depletion of functional alpha 2-antiplasmin, the primary plasmin inhibitor. These results indicate that, paradoxically, coronary thrombolysis with rt-PA involves depletion of endogenous factor XII-dependent fibrinolytic activity levels, which constitutes a risk for early myocardial reinfarction.

Aged↗
PubMed1991

Effect of a short course of 1,25-dihydroxyvitamin D3 on biochemical markers of bone remodeling in adult male volunteers.

To investigate the stimulatory effect of vitamin D on biochemical markers of bone remodeling, 15 normal men (aged 26-45 years, mean 33.2) were treated orally with 1,25-dihydroxyvitamin D3, 2 micrograms daily for 7 days, and followed for a total of 16 weeks. Serum concentrations of 1,25-dihydroxyvitamin D3 rose 43% during the first week (p less than 0.01), with no significant alteration in the level of 25-hydroxyvitamin D3. Serum level of immunoreactive parathyroid hormone (1-84) (iPTH) decreased markedly (p less than 0.02), and the maximal renal reabsorption capacity of phosphate (TmP/GFR) increased (p less than 0.05), both indicating the impact of the raised vitamin D level on target tissues. Serum phosphate and serum calcium increased during the treatment week (p less than 0.05), as did the fasting renal excretion of phosphate and calcium (p less than 0.01). However, a gradual fall in the excretion of hydroxyproline was seen in the observation period. The serum activity of acid phosphatase increased in the first weeks after vitamin D treatment, reaching significance at the end of week 2 (p less than 0.05). Acid phosphatase activity was still increased at the end of the observation period (p less than 0.02). These observations suggest a synchronization and recruitment of new bone resorptive cells. The immediate response to 1,25-dihydroxyvitamin D administration on the biochemical markers of formative bone cells was a marked increase in the serum level of osteocalcin (BGP), (p less than 0.002) with a gradually fall during the next weeks. A secondary increase, however, was observed in the last two months of the follow-up period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Induction and possible role of fibrinolysis in diabetes mellitus.

This article reviews the evidence supporting a relationship between an enhanced tissue injury, increased fibrin formation, defective fibrinolysis, and the evolution of the complications of late diabetic disease. Particular attention is drawn to the role of a defective endothelial cell mediated fibrinolysis with respect to increased fibrin formation and a delayed tissue repair in diabetic patients. Reviewed are studies that indicate that it is possible in patients with diabetes by means of sulfonylurea compounds to increase endothelial cell-produced t-PA without affecting PAI-1. It is advocated that potent compounds should be searched for, with the capability to modify the hemostatic process of the diabetic endothelial cell in order to express more fibrinolytic activity independent of the patient's metabolic state in an attempt to delay the complications of late diabetes.

Diabetes Mellitus↗
PubMed1991

Possible role of vascular intima for generation of coagulant activity in patients undergoing coronary thrombolysis with recombinant tissue-type plasminogen activator. A randomized, placebo-controlled study.

In our present placebo-controlled study on recombinant tissue-type plasminogen activator (rt-PA) and heparin treatment of patients with acute ischaemic heart disease (IHD), we studied the extent of fibrin resolution and generation of coagulant activity. In rt-PA treated patients the lysis of fibrin in vivo (median 60 nmol of fibrin--estimated as fibrinogen equivalents) was significantly higher (p less than 0.02) than can be accounted for solely by lysis of a coronary thrombus (approximately 2 nmol) and circulating soluble fibrin (median 15 nmol). We observed a 200% increase of plasma concentrations of both prothrombin fragment 1 + 2 (p less than 0.001) and thrombin-antithrombin III complexes (p less than 0.001) as a consequence of rt-PA treatment, indicating that the coagulant activity is primarily caused by a physiological activation of the coagulation system. We conclude that an important contribution to the activation of coagulation in patients undergoing coronary thrombolysis is lysis of fibrin deposited widespread on the vascular intima, and that this process causes an intimal-dependent activation of the coagulation system.

Adolescent↗
PubMed1991

Influence of cytostatic treatment on the coagulation system and fibrinolysis in patients with non-Hodgkin's lymphomas and acute leukemias.

Cytostatic therapy is known to aggravate tumor-induced coagulopathy. Therefore, we have studied the effect of different chemotherapeutic regimens on the activation of coagulation and fibrinolysis in patients with non-Hodgkin's lymphomas or acute leukemias. In non-Hodgkin's lymphoma patients treated with an aggressive protocol (COL-BLAM) and in leukemia patients (TAD-9) fibrinopeptide A, prothrombin fragment (F1 + 2) and thrombin antithrombin III complexes (TAT) increased (Tables 4 and 6), while D-dimer did not deviate significantly. The ratio D-dimer/TAT consequently showed a significant decrease, indicating increased formation of thrombin after release of procoagulant factors, which is not paralleled by an activation of fibrinolysis. Both these groups were also characterized by an increase in uric acid and in C-reactive protein and plasminogen-activator inhibitor, two acute-phase reactants. In contrast, patients with non-Hodgkin's lymphomas treated with a less aggressive protocol (COP) showed no significant changes in hemostatic variables, uric acid, or acute-phase reactants. The release of procoagulant factors relates to the cytostatic sensitivity of the tumor and to a high tumor-cell destruction. Our results further emphasize the need for large-scale studies on antithrombotic prophylaxis in patients undergoing cytostatic treatment.

Acute Disease↗
PubMed1991

Increased serum concentrations of type I procollagen C-terminal propeptide and osteocalcin during a short course of calcitriol administration to adult male volunteers.

To investigate bone collagen metabolism during vitamin D treatment, 15 healthy males (aged 28-45 years, median 34) were treated orally with calcitriol, 2 micrograms daily for 7 days and followed for a total of 2 weeks. The serum concentration of calcitriol rose markedly (median difference and 95% confidence limits: 49% (5-82), p less than 0.005) during treatment, whereas serum levels of calcidiol, and calcium remained unchanged. The serum level of procollagen type I C-terminal propeptide rose 15% (7-33, p less than 0.003), whereas no alterations were observed concerning serum procollagen type III N-terminal propeptide, and serum hyaluronan. The serum concentration of osteocalcin rose concomitantly (26% (12-45), p less than 0.003). All values returned to baseline levels within seven days after the treatment week. The serum levels of osteocalcin and procollagen type I C-terminal propeptide were positively correlated (rs = 0.71, p less than 0.004) during the study. Serum procollagen type I C-terminal propeptide and serum osteocalcin did not correlate with serum procollagen type III N-terminal propeptide or serum hyaluronan either at baseline or after treatment. It is concluded that a short course of calcitriol administration to healthy males stimulates the biosynthesis of bone-related matrix proteins. By contrast, connective tissue components of predominantly extraosseous origin are not affected.

Administration, Oral↗
PubMed1991

Increased levels of fibrinolysis reaction products (D-dimer) in patients with decompensated alcoholic liver cirrhosis.

We studied the activation of coagulation and fibrinolysis in the blood of patients with compensated (n = 25) and decompensated (n = 25) liver cirrhosis. We observed increased blood concentrations of thrombin-antithrombin III (TAT) complexes (p less than 0.001) and of D-dimer (p less than 0.001) in both groups of patients compared with healthy volunteers (n = 25). The blood levels of tissue-type plasminogen activator (t-PA) activity (p less than 0.001) and the concentrations of t-PA antigen (p less than 0.001) were also significantly raised in both groups of patients compared with controls, whereas plasminogen activator inhibitor did not deviate. There were no significant differences in the determined variables between the two groups of patients except that the concentrations of D-dimer were significantly higher (p less than 0.001) in patients with decompensated liver cirrhosis. The ratio between D-dimer and TAT did not deviate between patients with compensated liver cirrhosis and healthy volunteers but was significantly increased in patients with decompensated liver cirrhosis. These observations indicate that efflux from the extravascular space (for example, ascitic fluid) contributes to the high concentrations of fibrin degradation products (D-dimer) in patients with decompensated liver cirrhosis. In addition, we conclude that patients with liver cirrhosis have an enhanced activation of both coagulation and fibrinolysis but that the balance between these two systems is not significantly displaced compared with healthy volunteers.

Aged↗
PubMed1991

Chronobiology of coronary risk markers in Greenland Eskimos: a comparative study with Caucasians residing in the same Arctic area.

We report a comparison of fibrinolytic variables between 10 Caucasians on a predominantly European diet and 10 Greenland Eskimos on a traditional Inuit diet containing a substantial amount of fish and sea animals. We studied the diurnal variation in tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) antigens and activities during a 24-h period. Blood samples were taken every 4 h. The variations of the sinusoidal curves were evaluated by the Friedman chi 2 test. t-PA and PAI-1 antigen in plasma fluctuated significantly during the 24 h (Eskimos p less than 0.00007 and p less than 0.0007; Caucasians p less than 0.00003 and p less than 0.02), with a peak in the early morning and a nadir in the afternoon. This also held true for PAI activity (Eskimos p less than 0.0008; Caucasians p less than 0.01), whereas t-PA activity showed an inverse but still significant pattern (Eskimos p less than 0.006; Caucasians p less than 0.0008). Amplitudes, areas underneath, and overall medians of the sinusoidal curves did not deviate between the two groups with respect to t-PA and PAI. In contrast to the significant variation of t-PA and PAI, the plasma concentrations of fibrin degradation products (D-Dimer), a measure of effective fibrinolysis, remained constant during the 24 h, and the absolute differences between groups did not reach statistical significance. These findings suggest that circadian variation of fibrinolytic activators and inhibitors is a basic biologic phenomenon, which is not affected by life-style, dietary habits, or ethnic differences.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Fibrinogen Kiel: a congenital dysfibrinogenaemia with (A alpha-16 Arg----His) substitution characterized by HPLC without prior isolation of fibrinogen.

A congenital fibrinogen variant in a German family is described which has been identified as a substitution of His in position 16 of the A alpha-chain for Arg, manifested over three generations in heterozygous form. The characterization is based on the reaction of the variant fibrinogen with thrombin and reptilase, on the HPLC-chromatographic properties and the amino acid composition of the abnormal fibrinopeptide A. Clinical observations in the affected family members (neither haemorrhagic nor thrombophilic tendencies), the results of routine coagulation tests (normal global clotting tests, prolonged thrombin and thrombin-coagulase time, decreased fibrinogen concentration in functional as opposed to immunological tests), and the autosomal co-dominant modus of inheritance of the fibrinogen variant are all in complete agreement with other reports in the literature concerning the same amino acid exchange. The results of our experiments with fibrinogen Kiel allow no definite conclusion regarding the question of whether it consists of pure homodimers or as of a mixture of homo- and heterodimers.

Amino Acids↗
PubMed1991

Interleukin-1 and tumor necrosis factor-alpha in plasma of patients with acute ischemic heart disease who undergo thrombolytic therapy: a randomized, placebo-controlled study.

In patients with acute ischemic heart disease who undergo thrombolytic therapy we have previously observed a marked endothelium-dependent activation of the coagulation system. Concomitantly the concentrations of the fast acting plasminogen activator inhibitor type 1 (PAI-1) in plasma increased. The results of recent in vitro studies would suggest that these in vivo phenomena could be associated with the procoagulant effects of the cytokines interleukin-1 (IL-1) and/or tumor necrosis factor-alpha (TNF). In the present placebo-controlled study on patients with acute ischemic heart disease treated with thrombolytic agents we observe low or undetectable concentrations, and insignificant deviations during the study periods, of IL-1 and TNF in plasma. We conclude that IL-1 and TNF play a minor role for generation of coagulant activity and systemic deviations of PAI-1 in patients who undergo coronary thrombolysis.

Acute Disease↗