Biomedical subjects

A A Pappas

Publications and source records attributed to A A Pappas.

61 records · Page 4Linked to original sources

PubMedDate not supplied

In vitro antimicrobial activity of diethyldithiocarbamate and dimethyldithiocarbamate against methicillin-resistant Staphylococcus.

Staphylococcus aureus has appeared which is highly resistant to both methicillin and aminoglycosides. Current therapy involves long-term intravenous therapy of vancomycin. Since vancomycin is currently the only drug used to treat these patients, there is a need to develop additional antimicrobial therapy. The in vitro antimicrobial effect of the metal chelator, diethyldithiocarbamate (DDTC) and its structural analog dimethyldithiocarbamate (DMTC) were investigated. Both DDTC and DMTC were effective against S. aureus including methicillin-resistant S. aureus (MRSA). By agar diffusion, DDTC at 10 micrograms per disk produced zone sizes of 12 to 21 mm and at 100 micrograms per disk produced zone sizes of 26 to 34 mm against MRSA. The DMTC produced slightly greater zone sizes against MRSA of 16 to 24 mm and 24 to 37 mm for 10 micrograms per disk and 100 micrograms per disk, respectively. The minimum inhibitory concentration (MIC) for DMTC against MRSA was 6 micrograms per ml. Both DDTC and DMTC were also effective against enterococci, Proteus mirabilis, Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, Enterobacter cloacae, Enterobacter aerogenes, Salmonella species, Serratia marcescens and Citrobacter freundii at 100 micrograms per disk. The MICs of DMTC for Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, Salmonella and Citrobacter freundii were approximately 128 micrograms per ml while the MICs for Proteus vulgaris, Proteus mirabilis, Pseudomonas aeruginosa and Serratia marcescens was greater than or equal to 256 micrograms per ml. In addition, DMTC was synergistic with gentamicin against MRSA and coagulase-negative staphylococcus species, Enterobacter cloacae, Klebsiella pneumoniae and Pseudomonas aeruginosa. Additive and synergistic effects of DMTC were displayed with gentamicin against S. aureus including methicillin-resistant S. aureus.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗

PubMedDate not supplied

Current status of radioligand antibodies in the treatment of malignancy.

Monoclonal anti-tumor antibodies labeled with a radioactive moiety present an exciting new approach to cancer therapy. With the advent of hybridoma technology, monoclonal antibodies can now be produced in quantity. Indeed, antibodies against tumor-related and tumor-specific antigens have been produced, labeled with a radioactive substance, and used therapeutically. The rationale for this therapeutic approach and the results of human clinical trials will be reported herein.

Antibodies, Monoclonal↗

PubMedDate not supplied

Status of current clinical tests for human immunodeficiency virus (HIV): applications and limitations.

Two laboratory tests are currently used to detect the human immunodeficiency virus (HIV) specific antibodies that are produced when an individual has been infected by the virus at some time. These include the enzyme-linked immunosorbent assay (ELISA) as the screening test and the Western blot (WB) as the confirmatory test. They are not yet optimally effective and have brought with them some problems, especially when used to screen low risk populations such as asymptomatic blood donors. Currently licensed ELISA tests used to detect HIV have sensitivities that range between 93 percent and 99 percent, and all have specificities greater than 99 percent. An important concern is that the positive predictive value for the ELISA screening test is low in spite of the fairly high sensitivity and high specificity values. This poor predictive value is due to the low prevalence of individuals in the general population who have been infected with HIV. Multiple causes of false positive ELISA and Western blot tests have been identified. They can be eliminated by utilizing reagent antigens which are produced by recombinant deoxyribonucleic acid (DNA). The false negative ELISA and Western blot tests can be reduced by tests designed to detect IgM antibodies to HIV.

Antibodies, Viral↗

PubMedDate not supplied

Prostatic acid phosphatase: clinical utility in detection, assessment, and monitoring carcinoma of the prostate.

Prostatic carcinoma is a significant cause of male cancer death. The majority of cases present as incurable disease. The measurement of acid phosphatase has served to confirm clinically suspected disease and staging. The immunochemical methods have increased clinical sensitivity and specificity in detecting curable occult or confined disease, but not significantly so as to warrant mass screening. Prostatic acid phosphatase remains a test for confirming clinical staging of prostatic carcinoma and a response factor to therapy at present.

Acid Phosphatase↗

PubMedDate not supplied

Laboratory identification of erythroblastosis fetalis.

The clinical laboratory assumes the paramount role of supplying accurate data to the attending physician for the diagnosis, treatment and prevention of HDN. Maternal prenatal testing identifies patients at risk for Rh-HDN. The antibody titer is of primary value in assessing patients as candidates for amniocentesis. Amniotic fluid analyses provide an assessment of fetal prognosis in HDN and also an assessment of gestational age, lung maturity, and placental function. In severe HDN, amniotic fluid analysis can indicate the need for intrauterine transfusion. Postnatal laboratory studies can confirm the suspected diagnosis of HDN, identify those neonates at risk of developing kernicturus, and provide the physician with information pertaining to the treatment of HDN. Finally, prenatal and postnatal laboratory testing identifies those females eligible for Rh-immune globulin therapy to prevent HDN in subsequent pregnancies.

ABO Blood-Group System↗

PubMedDate not supplied

The role of amniotic fluid phospholipids in determining fetal lung maturity.

Assessment of the status of amniotic fluid phospholipids (qualitative and semi-quantitative) has become important in determining fetal lung maturity. In uncomplicated pregnancies, it has been documented that the ratio of lecithin to sphingomyelin (L/S ratio), with respect to pediatric gestational age, is a reliable predictor of maturity. In complicated pregnancies (e.g., toxemia, diabetes mellitus) the L/S ratio may result in erroneous clinical interpretation and premature intervention. The presence of phosphatidyl-glycerol (PG) in these cases has been acknowledge to be a significant factor indicative of fetal lung maturity. Thin-layer chromatography, which clearly elucidates the six phospholipids of amniotic fluid, is the method of choice.

Amniotic Fluid↗

PubMedDate not supplied

The use of delta osmolality to predict serum isopropanol and acetone concentrations.

We investigated whether serum delta osmolality will predict the total serum concentration of isopropanol and acetone metabolite. Three isopropanol ingestions were monitored by delta osmolality determinations followed by quantification of serum isopropanol and acetone concentrations. The delta osmolality was established by routine chemical analysis and standard freezing point depression osmometry. Serum isopropanol and acetone levels were quantified by gas chromatography-head space analysis (GC-HS). Patients were initially suspected of having isopropanol intoxication secondary to an elevated delta osmolality discrepancy (measured - calculated > 10 mOsm). Serum concentrations versus delta osmolality were analyzed by linear regression (correlation coefficient r = 0.713; p < 0.05). The delta osmolality paralleled and decreased relative to the total low molecular weight of volatile concentration in each case. In emergencies, delta osmolality may be a screening test to identify rapidly patients at risk for complications associated with isopropanol ingestion when GC-HS is not available.

1-Propanol↗