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Biomedical subjects

E A Natelson

Publications and source records attributed to E A Natelson.

At least 37 records · Page 2Linked to original sources
PubMed1977

Grossly bloody urine of runners.

A study of 13 men with grossly bloody urine induced by running incriminated the urinary bladder neck or posterior urethra as the site of blood loss. Our evidence also showed that diet lacking in animal protein can play a causative role. The ailment seems to have no long-term sequelae and may not affect female runners. Although we recommend medical evaluation for any runner with gross hematuria, the extent of diagnostic work-up and any modification of the victim's training problem program will depend on the circumstances in each case.

Adult↗
PubMed1977

Inhibition of ristocetin-induced platelet agglutination by vancomycin.

Ristocetin and vancomycin are structurally similar glycopeptide antibiotics. Both vancomycin and ristocetin in high concentrations (3.0 mg/ml) cause the precipitation of fibrinogen, plasminogen, and IgG from platelet-poor plasma (PPP). In contrast to ristocetin, vanomycin (0.5-1.5 mg/ml) does not agglutinate platelets in normal platelet-rich plasma (PRP) or formalin-treated platelets in the presence of normal PPP. Preincubation of vancomycin (0.5-1.25 mg/ml) with normal PRP, von Willebrand platelets in normal PPP, or formalinized platelets results in inhibition of platelet agglutination induced by ristocetin (0.7-1.25 mg/ml) or ristocetin and normal PPP. This inhibition can be overcome by increasing the final concentration of ristocetin in the platelet suspension. Preincubation of formalin-treated platelets with the major fraction obtained by carboxymethyl-Sephadex C-50 chromatography of commercial vancomycin also results in inhibition of agglutination induced by ristocetin and normal PPP. Incubation with vancomycin (1.25 mg/ml) does not interfere with von Willebrand factor (vWF) or factor VIII coagulant activities in normal PPP or in Sepharose 4B void volume fractions of PPP. These results indicate that vancomycin interacts with normal, von Willebrand, and formalin-treated platelets and inhibits the binding of ristocetin (or ristocetin-vWF complexes).

Binding, Competitive↗
PubMed1976

Chronic consumption coagulopathy accompanying abdominal aortic aneurysm.

Each of two patients harboring a stable abdominal aortic aneurysm manifested severe recurrent bleeding consequent to chronic consumption coagulopathy (CCC). Both underwent successful aneurysmectomy, but in only one patient did bleeding cease and depressed clotting factors return to normal activity. In the other patient, subsequent observations suggested that his coagulopathy actually resulted from occult pancreatic carcinoma. We propose here criteria for establishing stable aneurysm as the cause of CCC and demonstrate the efficacy of heparin in reversing the coagulation defect prior to surgical intervention. These cases also illustrate that the discovery of CCC accompanying stable aneurysm may signal the presence of another underlying disorder.

Aged↗
PubMed1976

Influence of cephalosporin antibiotics on blood coagulation and platelet function.

Administration of cephalothin to normal volunteers in maximal doses of 300 mg/kg per day resulted in a combined defect of platelet function and blood coagulation. No such abnormalities were evident after infusion of cefazolin or cephapirin at a maximal dosage of 200 mg/kg per day. The observed thrombocytopathy was similar to but less severe than that induced by carbenicillin or ticarcillin and was not reflected by a prolonged bleeding time test or impaired prothrombin consumption. Moreover, it was not a consistent finding in those persons receiving cephalothin. A separate defect involving blood coagulation appeared to result from delayed fibrinogen-fibrin polymerization and was evidenced by extended values of the activated partial thromboplastin and thrombin time tests. It remains uncertain whether the abnormalities described may constitute clinically important hemostatic disorders in patients with normal renal function receiving large doses of cephalosporin antibiotics.

Blood Coagulation↗
PubMed1976

Defective platelet function following the administration of penicillin compounds.

Platelet function and blood coagulation were studied in five human volunteers receiving penicillin-G in incremental doses of 1.2--48 million U/day, in six volunteers receiving ampicillin in incremental doses of 60--300 mg/kg/day (4--20 g/day), and in six volunteers receiving methicillin in incremental doses of 60--300 mg/kg/day. Coagulation tests remained normal in all 17 volunteers. However, ADP-induced platelet aggregation became abnormal in every subject except one receiving ampicillin and one receiving methicillin. Defective aggregation occurred with predictability with the following doses: penicillin-G, 24 million U/day; ampicillin, 300 mg/kg/day; methicillin, 300 mg/kg/day. All volunteers given penicillin-G and all given ampicillin experienced dose-related prolongation of bleeding time which did not occur with methicillin. Striking prolongation of bleeding time occurred only with penicillin-G in doses of 48 million U/day. Other tests of platelet function including clot retraction, platelet factor 3 availability, and collagen-induced or epinephrine-induced aggregation remained normal during the administration of these drugs. Measurement of intracellular adenine nucleotides revealed that the ADP and ATP content of platelets was unaffected. It appears that at least one mechanism by which the penicillin compounds alter platelet behavior is by interfering with activation of these cells by ADP.

Adenosine Diphosphate↗
PubMed1976

A simple method of intraoperative autotransfusion.

A new method of intraoperative blood collection and autotransfusion can be incorporated into an available suction system. It combines systemic heparinization with immediate extracorporeal citrate phosphate dextrose anticoagulation. Analysis of the autologous blood collected and its recipients indicates that it is safe. The preservation of platelets, coagulation factors and erythrocyte oxygen carrying capacity is better in this autologous blood than in homologous banked units. Potential problems of autotransfusion exist, but they are minimized when this system is used.

Blood Preservation↗
PubMed1975

Detection of mild factor VIII Deficiency by thrombokinetics.

The maximal rate of change in optical density (Vmax-deltaOD)of plasma clots forming in the activated partial thromboplastin time test (APTT) may be significantly influenced by reductions in factor VIII activity insufficient to also cause a distinctly abnormal timed clotting endpoint. Analysis of relationships between Vmax-deltaOD of clotting plasma in the APTT, prothrombin time, and thrombin time tests provides a basis for increasing the screening value of the APTT in suggesting intrinsic system abnormalities. Three illustrative case reports support the added benefit of thrombokinetics in the detection of mild factor VIII deficiency in hemophilia A and in von Willebrand's disease.

Adult↗
PubMed1975

Study of the effects of ticarcillin on blood coagulation and platelet function.

Ticarcillin is a new semisynthetic penicillin similar to carbenicillin. Since carbenicillin has been shown to inhibit platelet function to such an extent that bleeding may accompany its use, an investigation of the effects of ticarcillin on hemostasis was made. The drug was administered to 17 human volunteers for periods of 3 to 10 days in intravenous doses of 100, 200, or 300 mg/kg per day (7 to 21 g/day). Serial studies of blood coagulation and platelet function indicated that coagulation was unaffected by ticarcillin but that platelet function became defective in all subjects. Abnormal platelet function was evidenced by lengthening of bleeding time (17 of 17 volunteers), depressed adenosine diphosphate-induced platelet aggregation (17 of 17), defective collagen-induced aggregation (15 of 17), and abnormal epinephrine-induced aggregation (10 of 17). Prothrombin consumption, due to reduced platelet procoagulant activity, was significantly decreased with a dose of 300 mg/kg per day. Comparison of results from this study with those from an earlier carbenicillin study revealed that ticarcillin at 300 mg/kg per day produces the same defects in hemostasis as does carbenicillin at 300 mg/kg per day, but that lower doses (100 or 200 mg/kg per day) of ticarcillin result in only a mild defect in platelet function. If the effective dose of ticarcillin is proven to be lower than the doses of carbenicillin currently employed for treatment of certain gram-negative infections, bleeding should not be a frequent complication of ticarcillin administration, when the drug is given to patients with normal renal function.

Blood Coagulation↗
PubMed1975

Rheological properties of fibrin clots. Effects of fibrinogen concentration, Factor XIII deficiency, and Factor XIII inhibition.

The effect of fibrinogen concentration, Factor XIII deficiency, and Factor XIII inhibition, utilizing hydroxylamine, on the formation of clot structure in vitro was studied in human platelet-free plasma systems. Rheological and biochemical techniques were employed to relate changes in clot elasticity and viscosity to clot structure formation following recalcification of citrate anticoagulated samples. Classical theories of linear viscoelasticity for swollen crosslinked materials were shown to give an excellent estimate of the number of covalent crosslinks per fibrin monomer, which is directly attainable from rheological data. SDS gel electrophoresis was utilized to show qualitatively that decreases in maximum clot elasticity, at constant fibrinogen concentration, are directly related to a decrease in Factor XIII-mediated intermolecular crosslinking. The use of the technique to investigate both kinetic and equilibrium crosslinking (or structure formation) abnormalities in plasma systems is discussed.

Blood Coagulation↗