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Biomedical subjects

E V Potter

Publications and source records attributed to E V Potter.

At least 19 recordsLinked to original sources
PubMed1985

Unilateral renal vein occlusion in rats.

To study the relationship of renal vein thrombosis to membranous glomerulonephritis with the nephrotic syndrome, we attempted to simulate the former by occluding to 0.5 mm one renal vein in rats. Although increased proteinuria did occur during the first 3 days after such occlusion, there was little difference from control animals in the amount of proteinuria thereafter, up to 46 days, and no evidence of membranous glomerulonephritis by light, immunofluorescent, or electron microscopy.

Animals↗
PubMed1984

Factor VIII-related antigen in occluded human arteries and grafts.

Direct immunofluorescence was used to determine the disposition of factor VIII-related antigen (VIIIR:Ag) in occluded arteries and grafts from patients undergoing reconstructive operation. The presence of VIIIR:Ag on the luminal surface of these vessels was equated with their endothelialization according to the work of others. In 12 of the 20 arteries examined, stain for VIIIR:Ag was absent or markedly reduced from the luminal surfaces, and in six more it was only present focally. The adventitial capillaries were brightly stained in most of these specimens. Both of two saphenous vein grafts and all of six Dacron grafts stained for VIIIR:Ag along their luminal surfaces and in the adventitial capillaries as brightly as normal arteries. However, all of eight Gore-tex grafts had little or no stain for VIIIR:Ag along their luminal surfaces, and the capillaries of the adventitia were not as plentiful as those in the normal arteries and Dacron grafts. With one exception, the Gore-tex grafts had become occluded less than 1 year after implantation, while the Dacron grafts had remained patent for 2 to 8 years. Thus many of the diseased arteries and the short-lived Gore-tex grafts were characterized by relative absence of VIIIR:Ag from their luminal surfaces, presumably reflecting the loss or absence of endothelialization.

Adult↗
PubMed1979

Extracellular factors, blood group antigens, and bacteriophage of nephritogenic and nonnephritogenic strains of M-type 12 streptococci.

Strains of M-type 12 streptococci from 18 patients with acute glomerulonephritis and 18 patients with uncomplicated pharyngitis were analyzed for in vitro production of streptolysin O, diphosphopyridine nucleotidase, hyaluronidase, streptokinase, streptolysin S, proteinase, hyaluronic acid, and fibrinogen-precipitating factor. In addition, relations to blood group antigens, lysogeny, and susceptibility to bacteriophage were determined. No significant differences were found between strains from nephritic and nonnephritic patients. By not indicating a role in the pathogenesis of poststreptococcal acute glomerulonephritis for any of the factors studied, these observations diminish the probability that these factors are of specific importance in this disease and thus direct our attention elsewhere.

Bacteriophages↗
PubMed1979

Variations in serum complement following inulin infusion in man.

Complement levels were determined in 12 normal human volunteers while receiving intravenous infusions of inulin for determination of standard inulin clearances. Significant decreases in beta IC globulin and total hemolytic complement activity were observed when inulin was infused, but not following infusion of saline as a control. These effects were noted only when steady-state inulin levels were greater than 26 mg%, suggesting a dose-dependent response. No evidence of increased coagulation was noted as measured by fibrinogen and fibrin degradation products. Since C4 levels remained largely unchanged following inulin infusion, it was concluded that the results most likely occurred through activation of the alternate complement pathway.

Adult↗
PubMed1978

Clinical healing two to six years after poststreptococcal glomerulonephritis in Trinidad.

To determine the incidence of chronic nephritis after poststreptococcal acute glomerulonephritis in Trinidad, 760 patients (41 adult) were examined two to six years after recovery from the illness, 344 being studied twice (four and six years). Only 1.8 per cent had persistent urine abnormalities on their last follow-up examination, and another 8.0 per cent had abnormalities that were transient or occurred only after the patient had assumed the lordotic position. In 1.4 per cent hypertension was present, whereas only one had azotemia. Both persistent urine abnormalities and hypertension increased in prevalence with age at onset of prior poststreptococcal glomerulonephritis but did not vary between sexes, races or epidemic versus endemic forms. Half the urine abnormalities present four years after recovery were absent two years later. Thus, poststreptococcal acute glomerulonephritis appears to have a low incidence of chronicity in Trinidad, with continuing resolution for more than four years.

Acute Disease↗
PubMed1978

Tropical acute rheumatic fever and associated streptococcal infections compared with concurrent acute glomerulonephritis.

Ninety-three patients with acute rheumatic fever and 195 patients with acute glomerulonephritis were observed in Trinidad during an outbreak of scabies with a high incidence of secondary streptococcal infections. Clinical and laboratory manifestations of ARF were the same as those seen in temperate zones, except that antistreptolysin O titers were less markedly increased. The patients with ARF were similar to those with AGN in respect to sex, race, location of residence, and living conditions, but were older and had markedly fewer skin infections. Currently prevalent nephritogenic streptococcal strains never were isolated from patients with ARF even when M55 streptococci appeared and led to an epidemic of AGN.

Acute Disease↗
PubMed1977

The families of patients with acute rheumatic fever or glomerulonephritis in Trinidad.

The families of 21 patients with acute rheumatic fever (ARF) and 44 patients with acute glomerulonephritis (AGN) in Trinidad were examined in their homes. The ARF and AGN families were equally large and crowded and they lived in the same largely rural areas. However, only 22% of the ARF family members had skin infections in contrast to 61% of the AGN family members. Sixty-eight per cent of skin infections in ARF families and 69% of skin infections in Agn families yielded group A streptococci. Throat cultures were positive in 19% of ARF family members and 25% of AGN family members. Thirty-two per cent of 51 group A strains isolated from ARF family members (29 from throat, 22 from skin) were M11 or "M41" strains which were associated with ARF during the study, while only 8% were M1, T4 (MNT or 60) or M55 strains which were associated with AGN. In contrast, 49% of 171 group A strains isolated from Agn family members (64 from throat, 107 from skin) were M1, T4 (MNT or 60) or M55 while only 10% were M11 or "M41." Serum antibody titers were similar in both groups: antistreptolysin-0 titers were not markedly increased in either while anti-hyaluronidase and/or antideoxyribonuclease-B titers were increased in both. Evidence of subclinical AGN was found equally often in both groups: 6% of each had abnormal urine and 4% of each had decreased serum complement while 2% of the ARF and 3% of the AGN family members had both abnormal urine and decreased serum complement.

Adolescent↗
PubMed1977

Occult lupus nephropathy: a correlated light, electron and immunofluorescent microscopic study.

Renal biopsies obtained from four adolescent girls who developed symptomatic thrombocytopenia with serologic evidence of systemic lupus erythematosus, without clinical signs of renal involvement, showed glomerular disease by electron and immunofluorescent microscopy with light microscopic changes in two cases. Subsequently, three of the patients developed proteinuria, and repeat biopsies from all four showed appearances ranging from resolution to significant glomerulitis. The findings illustrate the variable patterns of occult glomerulitis in lupus, and highlight the value of correlating light, electron and immunofluorescent studies in renal pathology.

Adolescent↗
PubMed1976

Absence of ristocetin aggregation factor from the skin of a patient with von Willebrand's disease.

Samples of apparently normal skin from one patient with von Willebrand's disease (vWD) and five patients without vWD were examined with fluorescein-tagged antiserum to the component of factor VIII required for aggregation of platelets by ristocetin (VIII-R.A.F.). No evidence of VIII-R.A.F. was found in the vWD skin, while bright granules were seen on and/or in the endothelial cells of dermal capillaries in all patients without vWD. VIII-R.A.F. granules were also found in the interstitial vasculature of all of twelve renal-biopsy specimens from patients without vWD. These observations support the concept that an abnormality of the vascular endothelium is involved in the pathogenesis of vWD.

Blood Platelets↗
PubMed1976

Failure of AHF concentration to control bleeding in von Willebrand's disease.

A newly available dried concentrate of antihemophilic factor (Profilate, Abbott Laboratories) was compared with standard, blood-bank prepared cryoprecipitate in the control of bleeding in a patient with von Willebrand's disease. Profilate effectively raised plasma levels of factor VIII but produced only half the expected increase in plasma ristocetin aggregation factor (RAF), and this RAF did not bind readily to the platelets in the presence of ristocetin. Furthermore, the Profilate had little effect upon the bleeding time or the clinical hemorrhage. In contrast, the cryoprecipitate did increase plasma RAF to the expected level, and this RAF bound readily to the patient's platelets in the presence of ristocetin. Cryoprecipitate promptly controlled bleeding. We conclude that the RAF present in Profilate retains in vitro activity but is incapable of augmenting platelet function in vivo.

Adult↗
PubMed1976

Immunoglobulin E in renal disease.

Samples of renal tissue from 373 patients were examined for the presence of immunoglobulin E (IgE) by immunofluorescent techniques. Only trace to ++ amounts ( on a scale of ++++) were found in 20 patients: 4/9 with post-streptococcal acute glomerulonephritis (GN), 5/30 with GN associated with systemic lupus erythematosus, 3/20 with membranous GN, 1/4 with Goodpasture's syndrome, 2/18 with recurrent microhematuria and focal GN, 1/5 with hemolytic anemia and uremia, 3/73 with renal homografts, and 1/5 with dermatomyositis. No IgE was found in 18 patients with lipoid nephrosis, 8 of whom were being treated with prednisone, nor in 5 patients with focal glomerular sclerosis and the nephrotic syndrome. Serum IgE was measured in 9 of the 20 patients with glomerular deposits of this globulin. With one exception, levels of IgE were within the range generally considered to be normal. However, they were greater than the mean of this range in all but two and near the highest limits of normal in most. Neither the amounts of serum IgE nor the degree of proteinuria could be related to the intensity of stain for IgE in the glomeruli of these patients.

Adolescent↗
PubMed1976

Platelet-bound ristocetin aggregation factor in normal subjects and patients with von Willebrand's disease.

Antiserum specific for that part of the factor VIII complex designated ristocetin aggregation factor (VIIIRAF) was prepared by immunizing rabbits with VIIIRAF derived from the plasma of a hemophilic patient with circulating antibody to factor VIII procoagulant activity (VIIIcoag). The rabbit antiserum prevented ristocetin-induced platelet aggregation and platelet retention by glass-bead columns. Although the antiserum also inactivated VIIIcoag in normal plasma, it did not inactivate VIIIcoag which had been dissociated from VIIIRAF by chromatography in 1 M NaCl, thus establishing the antigenic specificity of these two factors. When the VIIIRAF antibody was conjugated with fluorescein isothiocyanate and used to examine platelets from normal subjects and patients with von Willebrand's disease, the normal platelets showed a granular fluorescence similar to that observed with antifibrinogen serum whole von Willebrand platelets showed no fluorescent staining. The normal platelets retained the VIIIRAF granules during 18 hours incubation and 5 washings in artificial medium while the von Willebrand platelets failed to acquire granules after 18 hours in normal plasma. When the unstained platelets from patients with von Willebrand's disease were suspended in normal plasma and then aggregated by the addition of ristocetin, the aggregates not only stained brightly for VIIRAF, but fluorescent granules could be seen on individual platelets in the aggregates. These observations suggest that ristocetin causes the binding of VIIIRAF to platelets as well as platelet-to-platelet adhesion.

Blood Platelets↗
PubMed1975

Immunoglobulins and complement components in synovial fluid of patients with acute rheumatic fever.

Three components of complement and six other serum proteins were assayed in synovial fluid and serum samples from 25 patients with acute rheumatic fever in Trinidad. The resulting data indicate a relative decrease in both early and late components of complement within the synovial fluids which suggests local activation by immune complexes. Such activation of complement within the joint spaces may play a primary role in development of the inflammatory arthritis of acute rheumatic fever.

Adolescent↗