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Biomedical subjects

G F Pineo

Publications and source records attributed to G F Pineo.

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

Venous thromboembolism in neurosurgery and neurology patients: a review.

Thromboembolism is a common problem in neurosurgery and neurology patients. Within this diverse population are subpopulations of patients with varying degrees of thromboembolic risk: low, moderate, and high. Patients at substantial risk for deep vein thrombosis and pulmonary embolism include those with spinal cord injury, brain tumor, subarachnoid hemorrhage, head trauma, stroke, and patients undergoing a neurosurgical operation. There are prophylactic strategies that can be applied to these various risk groups that will dramatically reduce the incidence of thromboembolism. The risk of pulmonary embolism or fatal pulmonary embolism typically exceeds the risk of severe or fatal bleeding from adequate prophylaxis, and these techniques should be applied on a routine basis. To adequately care for patients with deep venous thrombosis and pulmonary embolism, the physician requires a thorough understanding of the methods of diagnosis, the pharmacokinetics of heparin and warfarin, and a knowledge of their role in the treatment strategies that have proven efficacy and safety. In addition, an awareness of the low molecular weight heparins and heparinoids is becoming essential. These new agents have a potentially promising role in both the prophylaxis and treatment of patients with neurological disease. The principles concerning the prophylaxis, diagnosis, and clinical management of venous thromboembolic disease in neurosurgery and neurology patients are dealt with in this review.

Anticoagulants↗
PubMed1993

Therapeutic use of low-molecular-weight heparins.

Accumulating evidence indicates that certain low-molecular-weight (LMW) heparins administered subcutaneously may replace classic intravenous heparin therapy. LMW heparins do not require monitoring and may be safer and more effective than unfractionated heparin. The decreased mortality rate, evident in two randomized trials, which was particularly striking in patients with metastatic carcinoma, requires confirmation. The simplified care offered by LMW heparin therapy raises the possibility of transferring care from in-hospital to out of hospital in uncomplicated patients with deep-vein thrombosis [Salzman EW: Low-molecular weight heparin and other new antithrombotic drugs. N Engl J Med 1992;326: 1017-1019]. The advantages to the patient of avoiding in-hospital care and its associated hazards are obvious. Outpatient LMW heparin therapy will likely prove to be highly cost-effective. It is uncertain at present whether the findings associated with an individual LMW heparin preparation can be extrapolated to a different LMW heparin. For this reason the findings of clinical trials apply only to the particular LMW heparin evaluated and cannot be generalized to the LMW heparins at large.

Animals↗
PubMed1993

Adverse effects of coumarin anticoagulants.

The biochemistry of vitamin K metabolism and the role of vitamin K-dependent gamma-carboxylation of the vitamin K-dependent coagulation factors are now well understood. Likewise, there is a clear understanding of the role of oral anticoagulants in the inhibition of these coagulation factors. However, the effect of oral anticoagulants on extrahepatic gamma-carboxylated proteins such as osteocalcin and matrix gamma-carboxyglutamate (Gla)-protein (MGP), and the effects of long term anticoagulants on bone mineral metabolism are just now being recognised. The relevance of these observations on mineral metabolism for elderly individuals, and in particular postmenopausal women who are on long term anticoagulants, is still unknown but worthy of continued close observation. The most significant hazard of oral anticoagulants is haemorrhage. Clinical trials continue to demonstrate that less intense (lower dosage) warfarin therapy can significantly decrease this risk of haemorrhage while at the same time providing equal efficacy when compared to more intense warfarin therapy. The more widespread use of the International Normalised Ratio (INR) for the control of anticoagulants will undoubtedly further decrease the risk of haemorrhage, but new innovations such as the use of ultra low-dose warfarin or newer techniques for the continued monitoring of oral anticoagulants are still required, particularly as the indications for oral anticoagulants continue to expand.

Coumarins↗
PubMed1993

Low-molecular-weight heparins for the treatment of venous thromboembolism.

Recent studies have indicated that certain low-molecular-weight heparins given subcutaneously may replace continuous intravenous unfractionated heparin for the treatment of venous thromboembolism. Low-molecular-weight heparins have a predictably high absorption rate when given subcutaneously and they do not require laboratory monitoring. These characteristics of low-molecular-weight heparin therapy raise the possibility of treating uncomplicated patients with deep venous thrombosis or pulmonary embolism in the outpatient setting. The advantages to the patient of avoiding in-hospital care and its associated hazards are obvious. Outpatient low-molecular-weight heparin will likely prove to be highly cost-effective. At the present time, the finding associated with an individual low-molecular-weight heparin preparation cannot be extrapolated to different low-molecular-weight heparins and each must be evaluated in separate clinical trials. Recent randomized clinical trials indicate that low-molecular-weight heparin may be safer and more effective than continuous intravenous unfractionated heparin in the treatment of proximal venous thrombosis. A decreased mortality rate, which was particularly striking in patients with metastatic carcinoma, was unexpected and requires confirmation in further prospective randomized trials.

Heparin, Low-Molecular-Weight↗
PubMed1993

Therapeutic use of low molecular weight heparins: the knowledge to date as applied to therapy.

Indeed, the accumulating evidence indicates that certain LMWH administered subcutaneously may replace classic intravenous heparin therapy. Certain of these subcutaneously administered LMWH do not require monitoring. The simplified care offered by LMWH therapy presents the possibility of transferring care from in-hospital to out of hospital in uncomplicated patients with deep vein thrombosis. The advantages to the patient of avoiding in-hospital care and its associated hazards are obvious. Outpatient LMWH therapy will likely prove to be highly cost-effective. It is uncertain at present whether the findings associated with an individual LMWH preparation can be extrapolated to a different LMWH. For this reason, the findings of clinical trials apply only to the particular LMWH evaluated and cannot be generalized to the LMWH at large.

Animals↗
PubMed1992

Subcutaneous low-molecular-weight heparin compared with continuous intravenous heparin in the treatment of proximal-vein thrombosis.

BACKGROUND: Low-molecular-weight heparin has a high bioavailability and a prolonged half-life in comparison with conventional unfractionated heparin. Limited data are available for low-molecular-weight heparin as compared with unfractionated heparin for the treatment of deep-vein thrombosis. METHODS: In a multicenter, double-blind clinical trial, we compared fixed-dose subcutaneous low-molecular-weight heparin given once daily with adjusted-dose intravenous heparin given by continuous infusion for the initial treatment of patients with proximal-vein thrombosis, using objective documentation of clinical outcomes. RESULTS: Six of 213 patients who received low-molecular-weight heparin (2.8 percent) and 15 of 219 patients who received intravenous heparin (6.9 percent) had new episodes of venous thromboembolism (P = 0.07; 95 percent confidence interval for the difference, 0.02 percent to 8.1 percent). Major bleeding associated with initial therapy occurred in 1 patient receiving low-molecular-weight heparin (0.5 percent) and in 11 patients receiving intravenous heparin (5.0 percent), a reduction in risk of 91 percent (P = 0.006). This apparent protection against major bleeding was lost during long-term therapy. Minor hemorrhagic complications were infrequent. Ten patients receiving low-molecular-weight heparin (4.7 percent) died, as compared with 21 patients receiving intravenous heparin (9.6 percent), a risk reduction of 51 percent (P = 0.049). CONCLUSIONS: Low-molecular-weight heparin is at least as effective and as safe as classic intravenous heparin therapy under the conditions of this study and more convenient to administer. The simplified therapy provided by low-molecular-weight heparin may allow patients with uncomplicated proximal deep-vein thrombosis to be cared for in an outpatient setting.

Double-Blind Method↗
PubMed1992

Treatment of venous thromboembolism with low molecular weight heparins.

The accumulating evidence indicates that certain LMW-heparins administered subcutaneously may replace classical intravenous heparin therapy. Certain of these subcutaneously administered LMW-heparins do not require monitoring. The simplified care offered by LMW-heparin therapy offers the possibility of transferring care from in the hospital to out of the hospital in uncomplicated patients with deep vein thrombosis. The advantages to the patient of avoiding in-hospital care and its associated hazards are obvious. Outpatient LMW-heparin therapy will likely prove to be highly cost-effective. It is uncertain at the present time whether the findings associated with an individual LMW-heparin preparation can be extrapolated to a different LMW-heparin. For this reason the findings of clinical trials apply only to the particular LMW-heparin evaluated and cannot be generalized to the LMW-heparins at large.

Double-Blind Method↗
PubMed1992

Optimal therapeutic level of heparin therapy in patients with venous thrombosis.

BACKGROUND: Audits of heparin sodium therapy suggest that heparin administration is fraught with difficulty. The literature indicates that the current clinical practice of intuitive ordering of heparin results in inadequate therapy because of fear of bleeding. The importance of exceeding the lower limit of the therapeutic range has been strongly supported by findings of prospective clinical trials. Firm evidence indicates that failure to exceed the lower limit is associated with unacceptably high rates of recurrent venous thromboembolism. By comparison, evidence supporting the risk of exceeding the upper limit of the therapeutic range is weak. OBJECTIVES: The purposes of this study were (1) to validate prospectively an approach designed to minimize the proportion of patients receiving subtherapeutic doses of heparin and (2) to determine the effectiveness and safety of decreasing the heparin dosage infused on the basis of activated partial thromboplastin time (APTT) prolongation reflecting both heparin and warfarin sodium effects. METHODS: We performed a randomized double-blind study evaluating a prescriptive approach to heparin administration in patients receiving heparin or heparin with warfarin. Thromboembolic and bleeding complications were objectively documented. RESULTS: Only 1% and 2% of patients had subtherapeutic heparin levels for 24 hours or more in the heparin and combined groups, respectively. Recurrent venous thromboembolism occurred infrequently in both groups (7%). Sixty-nine (69%) of 99 patients receiving combined therapy had supratherapeutic values, compared with 24 (24%) of 100 receiving heparin; bleeding complications occurred in 9% and 12%, respectively. CONCLUSIONS: Our findings demonstrate that no association exists between supratherapeutic APTT responses and bleeding, which is in direct contrast to the observed association between subtherapeutic APTT responses and recurrent venous thromboembolism.

Double-Blind Method↗
PubMed1987

Spontaneous renal artery thrombosis: successful lysis with streptokinase.

We report a case in which a renal scan and angiography revealed a renal artery thrombosis. The only presenting symptom was left flank pain and no predisposing factors could be found on clinical or laboratory examination. Local infusion of streptokinase through an intra-arterial catheter led to complete dissolution of the thrombus despite the fact that it had been present for 13 days. The renal scan immediately after thrombolysis demonstrated the dramatic return of function to the involved kidney, although a repeat scan at 3 months showed evidence of the previous ischemia. Selective fibrinolytic therapy offers an option to surgery in selected patients with renal artery thrombosis.

Adult↗
PubMed1986

Papular leukemids.

Skin lesions occurring in patients with leukemia may represent specific leukemic infiltrates or may manifest as nonspecific lesions not related to leukemic cell infiltration. Included in the latter are a number of nonspecific papular and nodular lesions generally called "leukemids." We present two patients with lesions we have categorized as papular leukemids.

Aged↗
PubMed1980

The relevance of platelet and fibrinogen kinetics and coagulation studies to extent of disease and performance status in patients with adenocarcinoma.

In this study of 18 cancer patients, results of laboratory evaluation of a "hypercoagulable state" have been correlated with the extent of the disease and the functional activity of the patients. Most coagulation tests were normal. Higher levels of serum fibrinogen degradation products were associated with wider dissemination of disease. Fibrinogen survival time (t1/2) was shorter in patients with extensive disease than in those with less extensive disease (P < 0.05); platelet t1/2 was also shorter in the former group, though not significantly. Coexistence of severest physical disability and extensive disease was associated with the most marked reduction of platelet and fibrinogen t1/2. There was little correlation between platelet and fibrinogen t1/2, thus suggesting independent mechanisms of destruction of the two blood components. We suggest that future studies of hemostatic changes in cancer patients should include assessment of impairment of physical performance of the patients, as well as the extent of the tumor.

Adenocarcinoma↗
PubMed1978

Preleukaemia and reticulocytosis: a case report with in vitro evidence for abnormal reticulocyte maturation.

A case of preleukaemia with marked reticulocytosis and a slightly reduced red cell 51Cr survival is presented. An in vitro 'reticulocyte survival' test suggested that the apparent reticulocytosis was due to delayed maturation of reticulocytes. The globin synthesis ratio suggested an abnormal ribonucleic acid. At autopsy, in addition to the findings of acute leukaemia, mesenteric lipodystrophy was discovered. This abnormality has been seen in patients with malignant diseases, especially lymphomas, but heretofore has not been reported in acute leukaemia.

Erythrocyte Aging↗
PubMed1976

An approach to immunotherapy using antibody to IgE in mast cell leukemia.

Passive immunotherapy was attempted in a patient with mast cell leukemia using antibody against IgE. The results of both in vitro and in vivo studies indicate that although receptor sites for IgE were retained by the malignant mast cell, a secretory defect was present characterized by the spontaneous release of histamine and an impaired secretory response to anti-IgE antibody. Anti-IgE antibody selectively and reproducibly reduced the number of circulating mast cells probably by facilitating their permanent uptake by the reticuloendothelial system. Tolerance was not achieved with high dose deaggregated sheep IgG, nor were we able to confirm the effectivity of immunochemotherapy based on linking chlorambucil to antibody directed against the tumor-associated "antigen" IgE.

Animals↗
PubMed1975

The role of sulfinpyrazone in the prevention of arterio-venous shunt thrombosis.

The effect of sulfinpyrazone on the incidence of thrombosis of arterio-venous shunts was investigated in a double-blind crossover study in 45 patients on chronic hemodialysis over a period of 12 months. The incidence of thrombosis was reduced from 0.64 thrombi per patient month when on placebo to 0.21 thrombi per patient month when on sulfinpryazone (P less than 0.001). The therapeutic effect was more striking in men than in women and became evident within a week of starting the drug. The side effects were minimal, requiring withdrawal from the study of only one patient. This crossover study strengthens the findings in the previous report that sulfinpyrazone is of value in the prevention of thrombosis.

Adult↗