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J J Marx

Publications and source records attributed to J J Marx.

At least 19 recordsLinked to original sources
PubMed1992

Relevance of pretransfusion incubation of platelets at 37 degrees C.

The effect of pretransfusion incubation of platelets at 37 degrees C was assessed because of the controversial reports about its relevance. A dual-label technique (111indium and 114mindium) was applied in 10 healthy subjects receiving warmed and unwarmed autologous platelets simultaneously. Fresh platelet concentrates were infused into five subjects, whereas the other five subjects received stored platelet concentrates. The mean platelet volume decreased in all platelet concentrates during incubation, reflecting the restoration of the discoid shape of the platelets. The mean decrease was 0.35 fL (P = .003). However, the initial recovery and the mean platelet life-span were not improved by this procedure. It was concluded that there is no evidence that brief warming of platelets has any beneficial effect on platelet viability in healthy volunteers.

Adult↗
PubMed1992

Increased hydrogen peroxide concentration in human tumor cells due to a nitroxide free radical.

Evidence is presented that the nitroxide free radical, TEMPO, at concentrations commonly used to prevent oxidative damage, increases the intracellular hydrogen peroxide concentration. To investigate the origin of this increased hydrogen peroxide concentration, we have incubated various human tumor cell lines with compounds interfering with the generation of active oxygen metabolites. Sodium azide, inhibitor of the respiratory chain, the iron-chelating agent desferrioxamine, superoxide dismutase and catalase had no effect on the hydrogen peroxide concentration. Metyrapone, inhibitor of the cytochrome P450 system, was demonstrated to decrease, but not completely prevent, the hydrogen peroxide production. N-ethylmaleimide, a sulphydryl-bond alkylating agent, was able to completely prevent the increased hydrogen peroxide production. We conclude that, by increasing the cellular hydrogen peroxide concentration, TEMPO exerts a pro-oxidant effect. This increase in hydrogen peroxide production seems to be mediated by the induction of oxidase activity in the cytochrome P450 system, but other cellular systems involved in electron transport may also play a role.

Catalase↗
PubMed1992

Can the magnesium content of mononuclear blood cells be altered by oral magnesium supplementation?

A randomized, double-blind, placebo-controlled trial was performed on a rigorously defined group of normal subjects to see if magnesium (Mg) supplementation could affect serum Mg levels or Mg content of mononuclear blood cells. Forty-nine subjects were randomized to either placebo, tablets containing 90% United States recommended daily allowance (USRDA) of Mg, or tablets containing 180% USRDA of Mg. We were unable to demonstrate a statistically significant increase in Mg content of mononuclear blood cells.

Adult↗
PubMed1992

The effect of oral iron supplementation on erythropoiesis in autologous blood donors.

The effect of oral iron supplementation on erythropoiesis was studied prospectively in 34 autologous blood donors. The subjects, all of whom were to undergo total hip surgery, had normal iron status at the start of the study. During the preoperative period, in which 4 units of blood were collected, 17 patients received oral iron supplementation with 287 mg of ferrous sulfate (105 mg of elemental iron/day), while 17 patients did not use any iron supplementation. Oral iron supplementation during the 4-week preoperative period lessened the decrease in ferritin levels after two phlebotomies. Neither the decrease in hemoglobin nor the increase in erythropoietin levels was influenced by iron supplementation. In both iron-supplemented and control patients, serum erythropoietin levels returned to initial values within a few days after surgery. In autologous blood donors with a normal iron status, the use of supplemental iron does not affect erythropoiesis and is insufficient to maintain iron stores.

Administration, Oral↗
PubMed1992

Prevalence of antibody to Borrelia burgdorferi by indirect fluorescent antibody assay, ELISA, and western immunoblot in healthy adults in Wisconsin and Arizona.

The prevalence of antibody to Borrelia burgdorferi in healthy adults from Wisconsin and Arizona was determined by indirect fluorescent antibody assay (IFA), ELISA, and Western immunoblotting. A total of 301 sera from adult volunteer blood donors were collected from three areas of Wisconsin and compared with 49 consecutive anonymous adult volunteer donor sera from Tucson, Arizona, an area without reported Lyme borreliosis. Regional differences in seropositivity were found for Western immunoblotting (34[11%] of 301 from Wisconsin and none of 49 from Tucson; P less than .01) but not IFA or ELISA. No correlation was found among Western immunoblotting and IFA or ELISA results. For persons living in Madison or Milwaukee, Wisconsin (cities not endemic for Lyme borreliosis), 19 (86%) of 22 with a positive Western blot, but only 12 (48%) of 25 with a positive IFA or ELISA, had a significant exposure risk to B. burgdorferi-infected Ixodes dammini (odds ratio, 6.9; 95% confidence interval, 1.4-43.5). Western blot results were consistent with epidemiologic exposure to B. burgdorferi and implied frequent asymptomatic infection among healthy adults living in or visiting areas endemic for Lyme borreliosis.

Adult↗
PubMed1992

Relation between magnesium and potassium concentrations in myocardium, skeletal muscle, and mononuclear blood cells.

Potassium and magnesium were measured in 26 cardiac surgery patients (right atrial appendage), 23 autopsy subjects (right atrial appendage, left ventricular free wall, and skeletal muscle), and 9 healthy volunteers (mononuclear blood cells) to determine whether there was a relation between these two ions in the tissues measured. In the cardiac surgery patients, the potassium and magnesium concentrations were 46.35 +/- 3.89 and 4.40 +/- 0.58 (mean +/- SD, mumol/g wet weight tissue), respectively, and were significantly correlated (r = 0.54, P = 0.005). In the autopsy group, the respective concentrations were: for right atrial appendage, 30.54 +/- 10.18 and 3.66 +/- 0.70 mumol/g (r = 0.38, P = 0.14); left ventricular free wall, 60.69 +/- 17.93 and 7.74 +/- 1.73 mumol/g (r = 0.92, P = 0.0001); and skeletal muscle, 93.05 +/- 20.49 and 8.64 +/- 2.06 mumol/g (r = 0.91, P = 0.0001). In the healthy volunteer group, the results for potassium and magnesium in mononuclear blood cells were 42 +/- 9.9 and 3.99 +/- 0.70 fmol/cell, respectively (r = 0.94, P = 0.0001). Thus, potassium and magnesium concentrations were significantly correlated in all the tissues measured.

Aged↗
PubMed1991

Iron metabolism in patients with the anaemia of end-stage renal disease during treatment with recombinant human erythropoietin.

Iron metabolism was studied in 21 patients with the anaemia of end-stage renal disease during 40 weeks of treatment with recombinant human erythropoietin (rhEPO). Oral iron was prescribed to all patients. Initial serum iron concentrations and transferrin saturation levels were subnormal, decreased during the correction period of treatment, and increased thereafter. In 81% of patients in whom pretreatment transferrin saturation was below 0.25, transferrin saturation decreased below 0.16, despite sufficiently high serum ferritin levels. Serum ferritin concentrations decreased significantly. There was no correlation between serum ferritin levels and serum iron or transferrin saturation. Ferrokinetic studies, performed before and during treatment, showed an increase in plasma iron turnover, in erythron transferrin uptake, and in the flux of iron binding sites through the plasma. The rhEPO dose needed to keep the haematocrit at the target level during the maintenance period of treatment was significantly correlated with transferrin saturation, and iron binding capacity, but not with serum ferritin concentrations. This suggests that the functional availability of iron in plasma, rather than the size of body iron stores, is a major factor in the determination of the response to rhEPO treatment in end-stage renal disease.

Adolescent↗
PubMed1991

Diagnostic dilemma for the 1990s: Lyme disease versus rheumatic fever.

A 15-year-old boy developed an annular erythematous skin rash, fever, knee pain, syncope, and was found to be in complete heart block requiring temporary transvenous pacing. His recovery was complete following therapy with high dose steroids, aspirin, and IV ceftriaxone followed by oral penicillin. Serologic tests documented diagnostic levels of antibodies to Borrelia burgdorferi as well as to Group A streptococcal DNase B. Diagnoses of both Lyme disease and rheumatic fever are based on clinical presentation and serologic confirmation. Our patient had a clinical presentation compatible with either diagnosis and serologic test results suggestive of infection by both B burgdorferi and Group A streptococci. The patient's management was aimed at preventing complications of both diseases, since clinicians involved with the patient's case could not agree on the most likely diagnosis. We present this case to emphasize the following: both rheumatic fever and Lyme disease should be considered in patients presenting with annular skin rashes and complete heart block; serologic studies may be confusing in both Lyme disease and rheumatic fever since neither is entirely sensitive nor specific and efforts should be made to document the causative organism by appropriate cultures, biopsies, and stains when possible; and improved immunoserologic testing for Lyme disease, in particular, is highly needed.

Adolescent↗
PubMed1979

Mucosal uptake, mucosal transfer and retention of iron, measured by whole-body counting.

A method is described which enables simple and accurate measurement of the separate steps of iron absorption. A double isotope technique was used with 59Fe as a tracer and 51Cr (as CrCl3) as an inert, not absorbable indicator. With a whole-body counter it was possible not only to measure initial mucosal uptake and retention but also to calculate mucosal transfer of iron. Thus faeces collection for determination of mucosal uptake of iron was no longer necessary. Absorption of a physiological dose of inorganic iron was studied in 25 normal subjects (15 males and 10 females), in 21 patients with uncomplicated iron deficiency and in 8 patients with idiopathic haemosiderosis. A significant difference was demonstrated between normals and patients with iron deficiency and in idiopathic haemosiderosis with respect to the various steps of iron absorption. The method provides a simple tool for the study of the regulation of iron absorption at the luminal and intracellular site of the intestinal mucosal cell.

Adolescent↗
PubMed1979

Characterization of precipitin response to Micropolyspora faeni in farmer's lung disease by quantitative immunoelectrophoresis.

Sera from 12 patients with farmer's lung disease (FLD) drawn during an acute episode and displaying precipitins to Micropolyspora faeni were analyzed by crossed immunoelectrophoresis with an intermediate gel combined with a rabbit reference precipitate system. Forty-six precipitin arcs were identified in the reference system, and FLD sera reacted with 36 of these antigens. The FLD sera displayed significantly more precipitates and higher precipitin scores when compared with sera from 16 precipitin-positive subjectw who did not have FLD. However, there was overlap between the 2 groups, and neither measurement distinguished the 2 persons who became ill after challenge from one person who did not. Three disease specific antigens were identified that may have special relevance for pathogenesis of disease. Ten exposure-relevant antigens were also identified. We propose that these antigens be important components of a standardized M. faeni antigen preparation.

Chronic Disease↗
PubMed1979

Normal iron absorption and decreased red cell iron uptake in the aged.

Absorption of iron was studied with a double-isotope technique that allowed differentiation between "mucosal uptake," "mucosal transfer," and ultimate "retention" of iron. A physiologic dose of ferrous sulfate was administered to 25 healthy young adults, 40 active aged persons, and 20 patients with uncomplicated iron deficiency. Radioactivity was measured with a whole-body scanner. Iron absorption values were not decreased in aged subjects compared to young adults. Mucosal uptake, mucosal transfer, and retention of iron were equally increased in both young and old patients with iron deficiency. In 12 young adults and 33 aged persons red cell iron uptake was studied in addition to iron absorption. Young adults utilized 91% of the retained, orally administered iron and the aged only 66%. An increase in ineffective erythropoiesis in old age is suggested.

Absorption↗
PubMed1978

Farmer's lung disease among farmers with precipitating antibodies to the thermophilic actinomycetes: a clinical and immunologic study.

Farmers were evaluated for the presence of farmer's lung disease by serologic methods and by clinical histories. From a large farming population screened serologically, 40 of 92 farmers with precipitating antibodies to the thermophilic actinomycetes consented to be evaluated for clinical evidence of farmer's lung disease. Each subject completed a standardized questionnaire which was reviewd by a trained observer. On the basis of the questionnaire and an indepth clinical history, the subjects were grouped into those farmers who had a history of farmer's lung disease (38%), those with no history (50%), or a doubtful group (12%). When these groups were compared for radiologic changes, pulmonary function abnormalities, and immune function, no differences were discernible. None of the parameters tested were useful in predicting which farmer would develop clinical farmer's lung disease. The parameters tested did not provide reliable criteria for differentiating those patients who present without acute symptoms but relate a history of recurrent pulmonary illnesses associated with moldy forage.

Actinomycetales↗
PubMed1978

Case report.

Explore the source record for details and available documents.

Adolescent↗
PubMed1977

Immunological studies on an aberrant form of ataxia telangiectasia.

We describe two brothers with ataxia telangiectasia (AT) of which one was unique in that he had no detectable IgG and IgA concentrations in the serum or saliva. The other brother had the more common IgA deficiency in the serum and saliva. Neither patient had a history of undue sinopulmonary infections. In spite of the absence of these immunoglobulins in the sera, there were cells in the bone marrow and peripheral blood that stained with fluorescein-labeled anti-IgG and anit-IgA. Both patients had demonstrable humoral antibody and cell-mediated immune responses to the antigens tested. We also discuss possible pathophysiological mechanisms causing the above defects.

Adult↗