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Biomedical subjects

D Green

Publications and source records attributed to D Green.

At least 19 recordsLinked to original sources
PubMed1992

Transforming growth factor-beta 1 differentially regulates proliferation and MHC class-II antigen expression in forebrain and brainstem astrocyte primary cultures.

To facilitate investigation of cytokine regulation of reactive astrogliosis, primary astrocyte cultures from neonatal murine forebrain and brainstem were established. Forebrain and brainstem astrocytes proliferated at a similar rate under basal culture conditions, and both were growth-inhibited by treatment with recombinant murine interferon-gamma. The growth of cultured brainstem astrocytes was significantly enhanced by exposure to recombinant human transforming growth factor-beta 1. In contrast, proliferation of forebrain astrocytes was not significantly affected by transforming growth factor-beta 1. The disparate responses of brainstem and forebrain astrocytes to transforming growth factor-beta 1 treatment were not limited to effects on cell growth, since transforming growth factor-beta 1 could block interferon-gamma-induced MHC class-II antigen expression on cultured brainstem astrocytes but not on forebrain cells. Results could not be attributed to use of an heterologous cytokine/cellular target system, since similar variability in transforming growth factor-beta 1 modulation of major histocompatibility complex antigen expression could be demonstrated using two human astrocytoma cell lines. This report is the first to document mitogenic response to transforming growth factor-beta 1 for neuroepithelial cells. The role of transforming growth factor-beta 1 in regulating aspects of reactive astrogliosis, particularly in the context of inflammatory demyelination, requires further investigation. Furthermore, these studies may provide insight into regional variability in the sequelae of inflammation within the central nervous system.

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

Antiphospholipid antibodies and arterial thrombosis. Case reports and a review of the literature.

Antiphospholipid antibodies are a relatively heterogeneous mix of immunoglobulins with binding specificities for negatively charged or neutral phospholipids. Currently, the most commonly detected antiphospholipid antibodies include the anticardiolipin antibody, the lupus anticoagulant, and an antibody implicated in false-positive VDRL testing. Recently, a clinical syndrome of vaso-occlusive disorders associated with antiphospholipid antibodies has been identified and may result from immune-mediated disruption of endothelial function. This clinical syndrome encompasses arterial and venous thrombosis, recurrent fetal loss, neurologic dysfunction (eg, migraine, chorea, and encephalopathy), systemic and pulmonary arterial hypertension, and endocardial disease. Although most commonly associated with systemic lupus erythematosus, the antiphospholipid antibody syndrome also has been identified in patients with vaso-occlusive disease without systemic lupus erythematosus. Recently, identification of antiphospholipid antibodies has been facilitated by the development of a more sensitive assay for anticardiolipin antibody. In this article, case histories of three patients with arterial thrombosis and associated anticardiolipin antibodies, including the first associated case of terminal aortic thrombosis, are reviewed and the subject of the antiphospholipid antibody syndrome is discussed.

Adult↗
PubMed1992

Isolation of anonymous DNA markers for human chromosome 22q11 from a flow-sorted library, and mapping using hybrids from patients with DiGeorge syndrome.

DiGeorge syndrome (DGS) is a human developmental defect of the structures derived from the third and fourth pharyngeal pouches. It apparently arises due to deletion of 22q11. We describe a strategy for the isolation of DNA probes for this region. A deleted chromosome 22, which includes 22q11, was flow-sorted from a lymphoblastoid cell line of a patient with cat eye syndrome and used as the source of DNA. A DNA library was constructed from this chromosome by cloning into the EcoR1 site of the vector Lambda gt10. Inserts were amplified by PCR and mapped using a somatic cell hybrid panel of this region. Out of 32 probes, 14 were mapped to 22q11. These probes were further sublocalised within the region by dosage analysis of DGS patients, and by the use of two new hybrid cell lines which we have produced from DGS patients. One of these lines (7939B662) contains the altered human chromosome segregated from its normal homologue. This chromosome 22 contains an interstitial deletion in 22q11, and will be useful for localising further probes to the DGS region.

Base Sequence↗
PubMed1992

Lower limb paralysis: its effect on the recanalization of deep-vein thrombosis.

Fifty patients with lower limb deep-vein thrombosis (DVT) confirmed by venography were studied prospectively to determine the time required for recanalization. The patients were anticoagulated with heparin and warfarin for at least three months; impedance plethysmography, Doppler, and duplex scans were repeated at scheduled intervals. The 24 patients who were paralyzed took longer for recanalization than did the 26 nonparalyzed patients; this difference was statistically significant between the paraplegic-quadriplegic and nonparalyzed groups (54 vs 33 days; t = 2.12, p = .04). Patients with motor complete paraplegia or quadriplegia took longest for recanalization (57 days). Although most variables were not statistically significant on comparison, a somewhat longer recanalization time was seen in men and in those with DVTs located more proximally. Because of delay in recanalization, patients with lower limb paralysis may have persistent swelling due to venous insufficiency and may be at greater risk for development of the postphlebitic syndrome.

Adult↗
PubMed1992

Autoerythrocyte sensitization syndrome (psychogenic purpura).

A case of autoerythrocyte sensitization syndrome is reported. This syndrome most often appears in young women who have an underlying emotional disorder; features include bizarre, tender ecchymotic lesions, which are most commonly located on the arms and legs. Systemic symptoms often accompany the onset of these lesions. A diagnosis of autoerythrocyte sensitization syndrome may be made in a patient who has the typical history and clinical picture of the syndrome and in whom a skin test with use of the patient's blood reveals a positive reaction.

Acute Disease↗
PubMed1992

Effect of acute plasma volume expansion on peripheral arteriolar tone in healthy subjects.

1. Using venous occlusion plethysmography, we have investigated the forearm blood flow response in healthy subjects to the acute plasma volume expansion caused by a rapid intravenous infusion of saline. The contribution made to this response by nitric oxide has been investigated using local intra-arterial infusions of the nitric oxide synthase inhibitor NG-monomethyl-L-arginine. 2. The infusion of 1000 ml of saline over 25 min caused plasma volume to increase by about 7%, and resulted in a rise in forearm blood flow, with no change in arterial blood pressure. The onset of the blood flow response occurred within 10 min and blood flow remained elevated above baseline 20 min after the end of the saline infusion. 3. Local intra-arterial infusion of NG-monomethyl-L-arginine alone caused a reduction in forearm blood flow which was maximal at the end of the infusion and gradually recovered to baseline levels over 40 min. 4. When local intra-arterial infusion of NG-monomethyl-L-arginine was followed by plasma volume expansion, the calculated effect of NG-monomethyl-L-arginine was such as to abolish the vasodilator response to saline. 5. The effect of local intra-arterial infusion of NG-monomethyl-L-arginine on forearm blood flow was greater when the drug was given after volume expansion had occurred, than when it was given before the administration of saline. However, in control experiments the vasoconstrictor response to noradrenaline was also enhanced after the administration of the volume load in comparison with the response to noradrenaline given alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Arginine↗
PubMed1992

Amyloidosis in association with human immunodeficiency virus infection.

Amyloidosis has not been previously reported in association with human immunodeficiency virus (HIV) infection. An HIV-infected patient with hemophilia who developed nephrotic syndrome due to amyloidosis is described. Amyloid disease has been observed in monkeys with AIDS, and patients with AIDS have had elevated levels of amyloid A protein, findings that suggest a pathogenetic linkage between the two disorders. Amyloidosis should be considered in the differential diagnosis of HIV-associated nephropathy and the nephrotic syndrome in HIV-infected patients.

Adult↗
PubMed1992

HLA-D region genes and rheumatoid arthritis (RA): importance of DR and DQ genes in conferring susceptibility to RA.

The distribution of HLA-D region antigens was studied in three groups (I, IIa, and IIb) of patients with rheumatoid arthritis (RA): group I comprised 43 patients with mild, non-progressive RA, controlled by non-steroidal anti-inflammatory drugs without progression or erosions; group II comprised 94 patients with severe disease, who had earlier been treated with non-steroidal anti-inflammatory drugs and all had incomplete response requiring treatment with gold (sodium aurothiomalate). Of these, 46 patients (group IIa) responded to gold and the disease was well controlled, and the remaining 48 patients (group IIb) did not respond to gold and developed gold induced toxic reactions, including thrombocytopenia or proteinuria, or both. HLA-D region antigens were defined by serological and molecular (Southern blot analysis and oligonucleotide typing) techniques. The results show that DR4 was significantly increased in all three groups of patients. The prevalence of DR1, or DR1 in DR4 negative patients, and DR3 and DR4 associated DQw7 specificities, however, showed differences in these three groups of patients. The prevalence of DR1 and of DR1 in DR4 negative patients was increased only in patients with mild (group I) RA, but not in patients with severe (groups IIa and IIb) disease. On the other hand, the prevalence of DR4 associated DQw7 was significantly increased in patients with severe disease, but not in patients with mild RA. In addition, DR3 was significantly increased only in patients with severe disease who developed gold induced toxic reactions (group IIb). These data suggest that the HLA-D region genes which cause susceptibility to mild RA may be different from those causing susceptibility to severe RA. The results suggest that both DR and DQ (A, B) genes may be important in conferring susceptibility to RA: DR in mild disease and DQ in severe RA.

Antibodies, Antinuclear↗
PubMed1992

Protein S deficiency in middle-aged women with stroke.

We examined the relationship between free protein S deficiency and cerebrovascular disease by reviewing the records of all patients with the diagnoses of cerebral thrombosis, cerebral embolism, and cerebral vascular occlusion who were referred for coagulation studies over a 12-month period. We assayed for free protein S antigen, protein C antigen, and antithrombin III and tested for lupus-like anticoagulant and anticardiolipin antibody. Twenty-two of 267 patients (8.2%) admitted with thrombotic strokes were referred for coagulation studies. Free protein S antigen was significantly lower in women than in men (62 +/- 25% versus 88 +/- 24%, p = 0.03; n = 11 in each group). Six women had free protein S antigen levels below the range recorded for a contemporary group of 24 age-matched normal women (17 to 59% versus 70 to 102%, p less than 0.001); four of these women had cerebral arterial thrombosis and two had venous dural sinus thrombosis. The six women were aged 29 to 55 at the time of their first strokes; two had family members with protein S deficiency, and one of these had died of a stroke at age 52. Other abnormalities in this population included a positive test for lupus-like anticoagulant or anticardiolipin in five patients, a modest decrease in protein S in two men, and one patient with an isolated deficiency of antithrombin III. We conclude that protein S deficiency may be an important risk factor for stroke in middle-aged women but this requires confirmation by prospective studies in unselected patients.

Adult↗
PubMed1992

Electroencephalographic sleep and mood during cocaine withdrawal.

We report on nine patients between the ages of 21 and 39 years who were admitted to an inpatient substance abuse treatment unit for cocaine treatment. The patients' sleep was studied in the laboratory for 4 nights during the first week, and 2 nights during the second and third weeks of their hospitalization. Daily mood ratings, cocaine craving scores and sleep logs were also recorded on each patient. During the first week of withdrawal, these patients had a markedly shortened REM latency, an increased REM sleep percentage, a very high REM density and a long total sleep period time. During the third week, REM latencies were very short and total percentage of REM sleep was increased. By week three of withdrawal the sleep continuity pattern was similar to that found in chronic insomnia, with a long sleep latency, an abnormally increased total time awake after sleep onset and a poor sleep efficiency. The subjects' ratings of cocaine craving, total POMS scores and depression fell precipitously after the first week of withdrawal and were at sub-clinical levels by week three of withdrawal.

Adult↗
PubMed1992

The effects of local anesthetics containing epinephrine on digital blood perfusion. 1978.

Digital perfusion research was conducted with two local anesthetics, lidocaine and bupivacaine. The studies were performed utilizing both anesthetic agents, plain and with various concentrations of epinephrine. The drugs' effects on blood perfusion over a 24-hr. period were recorded and discussed. The onset and duration of anesthesia were also compared.

Anesthesia, Local↗
PubMed1992

Sclerotherapy for varicose and telangiectatic veins.

Varicose veins of the lower extremities are present in approximately 20 percent of adults. They are often symptomatic and may contribute to the development of cutaneous changes of venous insufficiency. Sclerotherapy is a nonsurgical procedure to eradicate varicosities. It can be performed in the office and is more cost-effective than traditional surgical vein stripping, which requires hospitalization and a recuperation period. Sclerotherapy is relatively safe and effective and may be used to treat both varicose veins and telangiectatic "spider" veins of the lower extremities.

Contraindications↗