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Biomedical subjects

G J Becker

Publications and source records attributed to G J Becker.

At least 181 records · Page 10Linked to original sources
PubMed1983

The exanthem of Ross River virus infection: histology, location of virus antigen and nature of inflammatory infiltrate.

The exanthem of epidemic polyarthritis, a disease caused by Ross River (RR) virus, was examined three days after onset of the common erythematous and the rare purpuric forms of the eruption. The dermis showed a light perivascular infiltrate of mononuclear cells in both, with extravasation of erythrocytes in the latter. No immunoglobulins (IgM, IgG, IgA) or complement components (Clq, C3) were detected. Most of the infiltrating cells were T lymphocytes of the T suppressor-cytotoxic class. Their perivascular location, the scarcity of other lymphocytes or phagocytes, and rapid resolution of the rash indicated that the T lymphocytes were responsible for cytotoxic destruction of virus-infected cells. A few monocyte-macrophage cells were identified in the perivascular infiltrate. RR virus antigen was found in the basal epidermal and eccrine duct epithelial cells of both types of lesion and in the perivascular zone of the erythematous lesion, but appeared to have been eliminated from this region in the purpuric lesion. It is suggested that secondary effects of the T-cytotoxic reaction on nearby capillaries are responsible for erythema, oedema and purpura in the exanthem.

Adult↗
PubMed1983

Thrombolytic agents: effects of local infusion on microvascular physiology and macrovascular ultrastructure.

Microvascular responses in live preparations of rat cremaster muscle were studied with intravital light microscopy following infusions of streptokinase, streptokinase-plasminogen complex, or urokinase into the iliac artery. Structural changes occurring in the endothelium of the iliac arteries were documented by electron microscopy. Though no functional microvascular changes were documented, endothelial cell injury and luminal surface fibrin deposits were identified in the iliac arteries locally infused with the thrombolytic agents. In addition, platelets in various stages of activation were identified. It is concluded that the commonly employed thrombolytic agents, urokinase and streptokinase, caused injury to the endothelial cells of our animal model. It is further concluded that platelet activation, due to local endothelial injury or some other mechanism, occurred following local infusion in our animal model. The long-term effects and potential clinical implications of the findings are not known.

Animals↗
PubMed1983

Low-dose fibrinolytic therapy. Results and new concepts.

The authors report their experience with the first 57 infusions (50 patients) in an ongoing study of local low-dose fibrinolysis for treatment of thromboembolic disease. Complete lysis occurred in nearly half of cases, while some therapeutic effect was demonstrable in more than two thirds. Success seems to be most directly related to the type of vessel infused, with the greatest success seen in vessels with no alternate pathways for egress of the fibrinolytic agent. Chronic fibrin deposits could also be treated with this technique. Since new thrombus formation occurs in a significant percentage of patients during local fibrinolytic therapy, the authors recommend cautious use of concomitant continuous intravenous heparin at a dosage sufficient to maintain the partial thromboplastin time at 1.5 times normal. While fibrinolytic therapy is usually not curative, it frequently facilitates detection of the underlying lesion, permitting definitive therapy.

Adult↗
PubMed1983

Digital vascular imaging: practical aspects.

Seventy-five pairs of digital subtraction angiogram images were evaluated for image quality by four independent observers. Each pair of images was derived from two separate injections in the same patient with only a single variable altered between injections, so that patients served as their own controls. The factors studied were contrast material iodine concentration, total volume of contrast material administered per injection, rate of contrast material injection, and catheter position. Observers consistently preferred images obtained following injection of the contrast agent with the higher concentration of iodine, following injection of the greater volume of contrast agent, and with the catheter placed in the superior vena cava rather than the basilic vein. No statistically significant difference in observer preference was found for the other categories studied.

Angiography↗
PubMed1983

Local thrombolytic therapy for subclavian and axillary vein thrombosis. Treatment of the thoracic inlet syndrome.

Four patients with primary subclavian-axillary vein thrombosis are described. Each patient received local thrombolytic therapy, resulting in reestablishment of antegrade flow via the axillary and subclavian veins. An intrinsic venous abnormality (perimural fibrosis and/or intimal dissection) identified at the first rib-clavicle junction (subclavian-axillary vein junction) was thought to be responsible for the thrombosis. One of the four patients subsequently underwent a surgical venous bypass of the abnormal segment, and a second underwent percutaneous transluminal angioplasty.

Adult↗
PubMed1983

Catheter-related thrombosis and fibrinolytic therapy.

Fifty-seven local transcatheter infusions of low doses of fibrinolytic agents for the treatment of occlusive vascular disease were performed in 49 patients. Thrombosis developed around the infusing catheter in 15 (26%) of these cases. Patients with occlusive vascular disease are at increased risk for the development of thrombosis around indwelling catheters because of the low flow state that exists proximal to the occlusion.

Adult↗
PubMed1983

Angiographic assessment of renal artery pathology: how reliable?

The accuracy of the angiographic interpretation of the histologic type of renal artery stenosis was assessed using a renal pathologist's diagnosis as the "gold standard." The angiograms of 42 renal artery stenoses were interpreted without other information, except age and gender, independently by six angiographers. This assessment indicated that angiography is not an accurate means by which to distinguish between the individual types of fibromuscular disease of the renal artery. However, it is a fairly accurate means by which to distinguish fibromuscular disease in general from atherosclerosis of the renal artery, 207 (82%) correct interpretations of 252. In addition, in the presence of renal artery stenosis, the absence of abdominal aortic atherosclerosis on angiography is an excellent predictor of fibromuscular renal artery disease, 17 (94%) of 18 specimens. Likewise, in the presence of a renal artery stenosis, angiographically demonstrable abdominal aortic atherosclerosis is a fair predictor of atherosclerotic renal artery disease, 16 (76%) of 21 specimens.

Adult↗
PubMed1983

The efficacy of various treatment modalities on aluminium associated bone disease.

We have studied the effects of desferrioxamine (DFO) or successful renal transplantation on eight patients identified as having aluminium associated bone disease. All patients showed dramatic subjective improvement in their bone pain and/or fractures. All histological parameters studied improved, with the more normal bone being found in the transplanted patients. Bone aluminium fell by at least 50 per cent. Biochemically, increased bone activity was indicated by a rising alkaline phosphatase. This was particularly marked in the DFO treated group who tended to show the development of hyperparathyroidism.

Adult↗
PubMed1982

A comparison of fixatives and immunohistochemical technics for use with monoclonal antibodies to cell surface antigens.

A variety of fixatives and four immunohistochemical technics were compared for demonstration of binding of monoclonal antibodies to cell surface antigens in tissue sections. Three recently described monoclonal antibodies, directed against the human leukocyte-common antigen (PHM 1) and antigens present on mononuclear phagocytes (PHM 2, PHM 3), were used. Antigen stability to fixation and heat were first assessed by quantitating the resultant effect on binding of the monoclonal antibodies to a macrophage cell line in vitro, using a radiolabeled second antibody. All fixatives affected their binding, but least effect was seen with formaldehyde-based fixatives and ethanol. Sections of formaldehyde- and ethanol-fixed lymph nodes were then labeled with monoclonal antibodies, and four developing methods were compared: indirect immunofluorescence, indirect immunoperoxidase, 3-layer heterologous peroxidase-antiperoxidase (PAP), and a 4-layer PAP technic. The 4-layer PAP proved to be the most sensitive technic since all three antibodies were localized successfully while both indirect technics only detected PHM 1, and the heterologous PAP method was not successful with any monoclonal antibody. The best combination of specific labeling and adequate morphology was seen with periodate-lysine-paraformaldehyde (PLP) fixation and the 4-layer PAP method.

Antibodies, Monoclonal↗
PubMed1982

Involvement of the macrophage in experimental chronic immune complex glomerulonephritis.

Serial renal biopsies for glomerular culture, histochemical staining for beta-glucuronidase, electron microscopy (EM) and light microscopy, were used to study macrophage involvement in experimental chronic immune complex (IC) glomerulonephritis (GN) induced in rabbits by daily intravenous injections of bovine serum albumin (BSA). In the 26 animals studied, proliferative GN of variable severity was induced, with mild disease in 5 animals, moderate proliferation in 15 and crescentic GN in 6. Macrophages first appeared in glomerular culture outgrowths during the 2nd and 3rd weeks, coincident with the onset of proteinuria and rising serum creatinine concentration. Large numbers of macrophages (in excess of 20 per glomerulus) were seen by the 5th weeks and persisted to the 9th week. The number of macrophages in outgrowths was not significantly greater in animals with crescentic disease. EM demonstrated macrophages in capillary loops, and in glomeruli with crescents, macrophages could be seen in the urinary space. Histochemical staining for beta-glucuronidase also demonstrated macrophages in the glomerular tuft and in crescents when present. These results indicate that macrophages constitute a considerable proportion of the glomerular hypercellularity seen in chronic IC glomerulonephritis.

Animals↗
PubMed1982

Contrast extravasation through Dacron grafts: a sequela of low-dose streptokinase therapy.

Local transcatheter administration of low-dose streptokinase for the treatment of thrombosed Dacron grafts was performed in four patients. Angiography after the infusion revealed extravasation of contrast material through the interstices of the graft. In each case the graft material was knitted Dacron, Surgically placed 1 month to 6 years before infusion with streptokinase. The fibrinolytic activity of streptokinase is likely responsible for lysis of the fibrin in the interstices of the graft with resultant extravasation of contrast material.

Aged↗
PubMed1981

Nonsurgical pneumoperitoneum.

The radiographic evidence of free air in the abdomen is usually associated with gastrointestinal perforations which represent a surgical emergency. However, pneumoperitoneum may also develop in a variety of benign conditions and following diagnostic or therapeutic procedures. This article provides a comprehensive list of nonsurgical causes of pneumoperitoneum.

Humans↗
PubMed1981

A technique for hemiacidrin dissolution of renal stone complicating an ileal conduit.

A technique for dissolving a renal stone complicating an ileal conduit is described. Free ureteric reflux was present, which allowed retrograde irrigation of the stone by infusion of hemiacidrin solution into the ileal conduit. With careful attention to urine infection and the pressure within the system, this technique might be applicable to other patients in whom free ureteric reflux is present and pyelolithotomy, percutaneous nephrostomy or the passage of ureteric catheters is difficult.

Adult↗
PubMed1981

Efficacy study of the small-bowel examination.

Retrospective analysis of 1,020 conventional antegrade small-bowel examinations revealed that the variable which correlated most highly with abnormal radiographic findings was the clinical complex of history, physical examination, and laboratory data which prompted suspicion of small-bowel disease. Thirty indications of possible small-bowel disease were divided into groups carrying (a) a high suspicion and (b) a low suspicion of disease. Pertinent abnormalities were revealed by 14.2% of examinations in the high-suspicion group, compared with 4.9% in the low-suspicion group. The individual indications covered a spectrum of 0-34% abnormality. Overall, 9.7% of examinations (99/1,020) revealed abnormalities, but only 6.6% (67/1,020) were pertinent to the clinical problems. The authors conclude that the efficacy of the small-bowel series is directly dependent upon the reason(s) for which it is performed.

Adolescent↗