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Biomedical subjects

L Marcus

Publications and source records attributed to L Marcus.

At least 19 recordsLinked to original sources
PubMed1996

First reported African case of Anaerobiospirillum succiniciproducens septicemia.

The first reported African case of septicemia caused by Anaerobiospirillum succiniciproducens is presented. The source of the infection was not identified. The clinical presentation and relative risk factors of the infection, and biochemical characteristics and antimicrobial susceptibility of the organism are described. Recommendations on appropriate antimicrobial therapy and postinfection sequelae are discussed.

Adult↗
PubMed1995

Determinants of HIV risk among men who have homosexual sex and inject drugs.

Men with histories of both homosexual contact and injecting drug use (IDU) are at increased risk of HIV infection over men who have only one such risk. Despite this, their special needs and circumstances have been neglected by AIDS prevention programmes. A survey of a wide spectrum of homosexual male IDUs was carried out in Melbourne and Sydney in 1993 to inform the development of specific policy and programmes for HIV prevention in these subcultures. Of 169 men, self-reported HIV prevalence was 27%. Decreasing compliance with safe sex guidelines (as measured by numbers of casual partners, participation in anal intercourse and use of condoms) was associated with HIV seropositivity, increased age, and increased participation in sex work; having a regular male partner was not protective against unsafe sexual behaviour, no matter the length of the relationship. A substantial proportion (15%) reported inconsistent condom use during anal sex with more than two partners in the preceding month: they were slightly more likely to be engaging in sex work, less 'stable' and more likely to be HIV infected. Sexual risk was not strongly associated with unsafe injecting, which was in general safe. Men who both have homosexual sex and inject drugs are groups at high risk of HIV, more from unsafe sex than from shared injecting equipment; men who believed themselves to be HIV infected were continuing to have sex in such a way that would allow transmission. These are clearly groups in need of priority targeted interventions.

Adolescent↗
PubMed1992

Mycotic keratitis caused by Curvularia brachyspora (Boedjin). A report of the first case.

Curvularia brachyspora has been identified for the first time as a cause of mycotic keratitis. Mycotic infections of the eye have assumed increasing importance in ophthalmology, resulting in a need for fungal identification and early specific treatment for the successful management of cases. A case of mycotic keratitis caused by C. brachyspora is described against the background of other Curvularia species causing mycoses.

Aged↗
PubMed1990

Social work in health care: directions in practice.

As technological advances within biomedicine uncover more complex and confusing situations, social workers are forced to deal with the patient and family with greater uncertainty. To competently address today's biomedical environment with an anticipation of tomorrow's advances is an incredible challenge. The focus of the theoretical framework necessary as the foundation for health care practice has shifted from an emphasis on psychopathology to a focus on what people do well, on their adaptive capacities with the goal of preventing maladaptive behavior. Therefore, the focus of practice must be on factors that affect normal or typical growth and development in the course of living and must include an understanding of the interaction between the biological, psychological, cognitive, social, cultural, and environmental dimensions of social functioning.

Ethics, Professional↗
PubMed1987

Effect of particle size of activated charcoal on separation of Triton X-100 from protein, liver cytosol, and lipoxygenase extracts.

Triton X-100 was almost completely removed from bovine serum albumin solutions, BALB/c mouse liver extracts, and avocado peel lipoxygenase extracts by stirring the samples for 30 min in the presence of 250-350 mesh activated charcoal. The procedure did not remove protein significantly and did not reduce enzyme activity. At higher charcoal particle sizes, the efficiency of Triton adsorption was decreased and protein adsorption was increased. ElevateD temperatures enhanced Triton and protein adsorption. Adsorption on activated charcoal of 250-350 mesh is a simple and rapid procedure for Triton removal at a ratio of 0.23 g Triton X-100 per gram of activated charcoal.

Animals↗
PubMed1987

Treatment of adverse digitalis effects by hemoperfusion through columns with antidigoxin antibodies bound to agarose polyacrolein microsphere beads.

Ten patients with an array of moderate to severe adverse effects resulting from digitalis were effectively treated by hemoperfusion through small columns which contained antidigoxin antibodies bound to polyacrolein microspheres in agarose macrospheres (APAMB). The procedure was well tolerated. There was no detectable damage to formed blood elements and no changes in electrolytes, liver enzymes, or other related biochemical parameters. Despite some theoretic considerations to the contrary, the removal of a relatively small load of digoxin resulted in amelioration of the clinical symptoms and ECG abnormalities associated with digitalis. No rebound phenomena of intoxication or posthemoperfusion increase in digoxin serum levels were noted over the subsequent 5 to 6 days. A further increase in the capacity of the columns may render this method a safe and convenient emergency procedure for patients with digitalis toxicity.

Acrolein↗
PubMed1986

Specific hemoperfusion through agarose acrobeads.

Agarose acrobeads were produced by encapsulating polyacrolein microspheres (acrobeads) of 0.2 micron average diameter within an agarose matrix. Crosslinked agarose acrobeads of diameters ranging from 0.5 to 0.8 mm were found to be optimal spheres for specific hemoperfusion purposes. Agarose provides the biocompatibility and mechanical strength of the agarose acrobeads. Acrobeads contain a high aldehyde-group content through which various amino ligands, i.e., proteins, antigens, antibodies, enzymes, and so on, can be covalently bound in a single step under physiological pH (or other pH). Thus, antibodies, antigens, or toxic materials may be directly removed from whole blood by hemoperfusion. During in vitro and in vivo hemoperfusion trials, the content of erythrocytes, leukocytes, and thrombocytes was essentially unaltered. Likewise, a battery of the soluble blood components (Cl-, K+, Na+, Ca2+, PO3/4-), total proteins, albumin, and C'4 component of the complement cascade, as well as the enzymes SGOT, LDH, and alkaline phosphatase, remained constant within narrow limits during the hemoperfusion procedure. The chemical and physical structure of the beads is stable; neither acrolein nor bead fragments were detected in hemoperfusion trials. Similarly, leakage of antibody bound to the agarose acrobeads into the blood is insignificant. Thus far, we have demonstrated the efficacy of the crosslinked agarose acrobeads for extracorporeal removal of "unwanted" substances from whole blood in the following systems: (a) removal of specific antigens (digoxin or paraquat removal with antidigoxin or antiparaquat antibodies bound to the acrobeads, respectively), (b) removal of specific antibody (antiBSA) removal with BSA bound to the beads), (c) removal of immune complexes (BSA-antiBSA complex removal with C1q bound to acrobeads), and (d) removal of specific metals (removal of iron with deferoxamine bound to the agarose acrobeads).

Animals↗
PubMed1985

Therapy of digoxin intoxication in dogs by specific hemoperfusion through agarose polyacrolein microsphere beads-antidigoxin antibodies.

The usefulness of a new biocompatible, specific immunosorbent, Agarose-Polyacrolein Microsphere Beads--Antidigoxin antibodies (APAMB-AD) for hemoperfusive removal of digoxin in digoxin intoxicated dogs is described. The sorbent contains antidigoxin antibodies covalently bound to polyacrolein microspheres, 0.2 micron in diameter. Thousands of microspheres are matrix-encapsulated in cross-linked agarose to form beads 500 to 800 micron in diameter. The sorbent removes digoxin specifically, leaving other components of the blood intact, in contrast to the nonspecific sorbents (charcoal and ion exchange resins) currently in use. Digoxin-intoxicated dogs looked ill, vomited, and their ECGs showed malignant arrhythmias which were reversed during the first hour of hemoperfusion. By 2 hours of hemoperfusion, the ECG tracings returned to the preintoxication state. Up to 27% of the total body digoxin burden was removed. The sorbent is biocompatible. Neither the formed elements nor a battery of the routinely assayed soluble components of the blood or complement (C'4) were altered significantly during the hemoperfusion trials. The dogs tolerated the hemoperfusion well and all survived the intoxication. Nonhemoperfused dogs or dogs whose blood was hemoperfused through beads lacking antidigoxin did not survive the digoxin intoxication.

Acrolein↗
PubMed1984

The rabbit as an animal model for haemoperfusion: surgical preparation and use.

In this paper the authors describe the surgical procedure to prepare rabbits for haemoperfusion experiments. The carotid artery and jugular vein are cannulated and a simple shunt device inserted to maintain patency of the vessels over a period of time. The cannulas and shunt remain patent and free of infection for some months. Specially designed outflow and inflow extracorporeal tubing sets minimize blood volume outside the body of the rabbit. The authors also illustrate the efficacy of this system in haemoperfusion trials to remove specific antibodies. Recently a system was described to remove mercury from the bloodstream of poisoned animals. The rabbit is a useful experimental animal for this type of haemoperfusion trial.

Animals↗
PubMed1984

Specific removal of digoxin by hemoperfusion through agarose polyacrolein microsphere polyacrolein microsphere beads-antidigoxin antibodies (APAMB-AD).

The efficacy of a new, biocompatible, specific immunosorbent for hemoperfusive removal of digoxin is described. The sorbent contains antidigoxin antibodies covalently bound to polyacrolein microspheres, 0.2 mu diam. Thousands of microspheres are matrix-encapsulated in crosslinked agarose to form beads of 500 to 800 mu diam. Digoxin intoxicated dogs showed heart block, ventricular and atrial tachycardia and extended runs of PVCs. During hemoperfusion the abnormal ECG abated; at 2 h of hemoperfusion the ECG tracings returned to normal. Up to 25% of the total digoxin burden was removed. The numbers of the blood cells and the content of a battery of relevant soluble components of the blood remained constant. Dogs were alive and well after the hemoperfusion. Non hemoperfused dogs, which received antiarrythmic agents, did not survive the intoxication. This is the first report of a practical hemoperfusive system for the specific removal of digoxin from whole blood.

Acrolein↗
PubMed1982

A new immunoadsorbent for hemoperfusion: agarose-polyacrolein microspheres beads. I. In vitro studies.

The development and properties of a novel adsorbent system consisting of polyacrolein microspheres encapsulated in agarose is described. In the model system, the microspheres contain covalently bound bovine serum albumin. In practice any protein or ligands with primary amino groups may be covalently bound. Circulating antibovine serum albumin antibodies were adsorbed from whole blood or serum of rabbits or goats onto the microspheres. The capacity of this batch is 10 mg antibody adsorbed/gm wet weight beads. When the column is operated at less than capacity, 50%, 70%, 90% and 95% of the anti BSA is adsorbed in 30, 60, 120 and 180 min, respectively. Thus, relatively short periods of hemoperfusion may be used. The beads are biocompatible. There are negligible decreases of RBC; up to a 10% decrease of WBC and up to a 20% decrease of platelets in 3 hrs. The beads are stable; neither breakdown nor leakage was observed over a period of 3 months. High flow rates were readily obtained. The mean diameter of the microspheres is 0.2 mu; the mean diameter of the agarose polyacrolein microspheres beads (APAMB) is 1.0 mm. We can produce monodisperse beads of any given diameter ranging from 200 mu to 1 cm.

Acrolein↗
PubMed1981

Some findings on the use of the adaptive behavior scale with autistic children.

Two studies on the use of the AAMD Adaptive Behavior Scale (ABS) with autistic children are reported. The first study compared ratings by parents and teachers on the same child. For Part I (Adaptive), significant correlations were found on total score and on 7 out of 10 individual scales. For Part II (Behavior), significant correlations were found on only 3 out of 14 scales and not on total score. The second study examined change measured by the ABS across an academic year. For Part I, significant change occurred on 5 of the 10 scales and on total score; for Part II significant differences were found on 2 of the 14 scales and not on total score. Correlations with IQ, Social Quotient (SQ), and degree of autism revealed a similar pattern. The implications of the differences between the two parts of the ABS and their utility for autistic children are discussed.

Adaptation, Psychological↗
PubMed1976

Amino acid sequence homology in 30 S ribosomal protein S19 from Bacillus stearothermophilus and Escherichia coli.

The amino therminal sequence of 30 S ribosomal protein S19 from Bacillus stearothermophilus has been determined. Comparison with the corresponding ribosomal protein from Escherichia coli reveals substantial sequence homology in the first thirty residues and provides further evidence for conservation of genetic information which specifies the primary structure of ribosomal proteins in these taxonomically dissimilar organisms.

Amino Acid Sequence↗