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Biomedical subjects

A A Pappas

Publications and source records attributed to A A Pappas.

At least 55 records · Page 3Linked to original sources
PubMed1985

Serum osmolality in acute intoxication: a prospective clinical study.

The authors prospectively performed simultaneous determinations of serum delta osmolality (delta-Osm), enzymic (alcohol dehydrogenase [ADH]) quantitation of serum ethanol (EtOH), and urine drug screens on 339 acutely intoxicated patients. In addition, the authors established reference ranges for measured and calculated serum osmolalities in a group of 55 healthy volunteers. The authors determined the clinical utility of the combined delta-Osm/ADH procedure for detecting the presence of EtOH or other low molecular weight (Mr) volatiles. In the reference population, the measured osmolality (M-Osm) and calculated osmolality (C-Osm) was 285.1 +/- 4.3 (SD) mOsm/kg and 287.4 +/- 5.1 (SD) mOsm/kg, respectively. The correlation between delta-OsM and serum EtOH was 0.968 in 151 patients in whom EtOH was detected. The presence of drugs in 67 (44%) patients or absence of drugs in 84 (55.6%) patients was shown to have no significant effect on the delta-Osm. The delta-Osm/ADH method failed to detect a volatile other than EtOH in only two cases (0.6%) or in addition to EtOH in three cases (0.9%). The concentrations of these volatiles were not clinically significant. The sensitivity for detecting EtOH by means of the delta-Osm calculation was 98.1% with a specificity of 98.2%. A disparity (delta-Osm greater than 10 mOsm/kg) between delta-Osm and the EtOH determination suggested a volatile other than EtOH in five cases (1.5%), which was confirmed by head-space gas chromatographic (GC-HS) analysis. A volatile in addition to EtOH in seven cases (2.1%) was suggested but not confirmed by GC-HS analysis. The delta-Osm/ADH procedure provides an efficient, rapid, and readily available method to evaluate the acutely intoxicated patient for the presence of EtOH and/or other low Mr volatiles.

Adult↗
PubMed1985

Wuchereria bancrofti in a Haitian immigrant.

A case of Wuchereria bancrofti filariasis was recently seen in a Haitian immigrant in Charleston, SC. The Caribbean area is a known endemic focus for this organism. With the increased numbers of immigrants from that area, it is likely that other such cases will be seen in the US.

Adult↗
PubMed1984

Cytomegalovirus pneumonia in sickle cell disease.

Cytomegalovirus (CMV) pneumonia frequently occurs in immunocompromised hosts. Unlike encapsulated bacteria and Mycoplasma, CMV pneumonia has not been reported in sickle cell disease. We describe a case of a healthy young man with sickle cell thalassemia who died with CMV pneumonia.

Adolescent↗
PubMed1983

Correlation of standardized serum protein determinations with calculated and measured colloid osmotic pressure.

The colloid osmotic pressure (COP) was measured on the serum of 250 individuals (healthy persons and patients) using a commercial oncometer. The total serum protein concentrations were measured by five methods, and the serum albumin concentrations were measured by four methods. The protein determinations were standardized as recommended by the Study Group on Proteins of the AACC Committee on Standards. The measured COP (mCOP) was correlated with each of the nine analytically determined protein concentrations. The mCOP also was correlated with a COP calculated (cCOP) from the Landis-Pappenheimer equation: cCOP = 2.1 (total protein [TP]) + 0.16 (TP)2 + 0.009 (TP)3. The authors found excellent linear correlations between mCOP and total protein concentration, and between mCOP and albumin concentration, when the protein determinations were standardized properly. The correlation between mCOP and protein concentrations was as good as the correlation between mCOP and cCOP in all cases. The serum albumin as determined by the DuPont ACA and mCOP gave the best linear relationship (r = 0.940) of the methods tested. Using the linear regression equation of albumin (ACA) versus mCOP, we were able to predict a cCOP to within +/- 3 mmHg for more than 95% of all samples tested.

Autoanalysis↗
PubMed1982

Detection and prevalence of IUD-associated Actinomyces colonization and related morbidity. A prospective study of 69,925 cervical smears.

Cervical Papanicolaou smears from 69,925 women were screened prospectively for the presence of Actinomyces israelii. The organism was not identified in non-intrauterine (contraceptive) device (IUD)-wearers. The prevalence of A israelii among IUD wearers ranged from 1.6% (general population) to 5.3% (clinic population). Protracted IUD use seemed to predispose to a higher incidence of infection. Direct immunofluorescence proved to be a more accurate and specific method of identification when compared with conventional light microscopy and anaerobic culture. Two of 112 women with direct immunofluorescence-proved A israelii had significant clinical infections. It appears that in the vast majority of cases, IUD-associated Actinomyces colonization produces only a superficial infestation. Conservative management is suggested for asymptomatic patients with cytologically detected Actinomyces to include removal of the IUD and repeated Papanicolaou smear after the next menstrual period.

Actinomyces↗
PubMed1982

Computerized calculation with osmolality and its automatic comparison with observed serum ethanol concentration.

The need to obtain blood alcohol levels in the differential diagnosis of the acutely intoxicated or unconscious patient often presents an emergency situation. By simultaneously determining the measured osmolality, the calculated osmolality, and the enzymatically-assayed ethanol level, the presence of alcohols other than ethanol can be recognized rapidly. A computer program has been written in FORTRAN to perform the necessary calculations, check for internal consistency, and alert the technologist if a disparity occurs.

Adult↗
PubMed1982

Improved one-dimensional thin-layer chromatography of phospholipids in amniotic fluid.

With this extraction procedure and chromatographic method, six amniotic fluid phospholipids [phosphatidylcholine (lecithin), sphingomyelin, phosphatidylinositol, phosphatidylserine, phosphatidylethanolamine, and phosphatidylglycerol] are completely resolved in less than 70 min from the time the specimen is received. The mobile phase (chloroform/petroleum ether/methanol/acetic acid, 5/3/1.6/1, by vol) is used with commercially available 7.5 X 10 cm silica-gel plates. The phospholipids are made visible by immersing the plate in cupric acetate/phosphoric acid. Lecithin/sphingomyelin (L/S) ratios are determined densitometrically. Rf values are well reproducible for both samples and standards, as are L/S ratios, and the method is simple and inexpensive. The relation between L/S ratios (for 100 specimens of amniotic fluid measured by this method) and fetal status is consistent with other reports. We confirm phosphatidylglycerol to be a sensitive indicator of fetal lung maturity: when it was detectable in amniotic fluid, the newborn invariably showed no symptoms of the respiratory distress syndrome.

Amniotic Fluid↗
PubMedDate not supplied

Comparison of derivatives for determination of codeine and morphine by gas chromatography/mass spectrometry.

Pentafluoropropionic anhydride (PFPA) and heptafluorobutyric anhydride (HFBA) derivatives of morphine and codeine demonstrated poor spectra due to low abundances of secondary and tertiary ions. Trifluoroacetamide (MBTFA) has been a widely used derivative; however, the internal standard, nalorphine, displayed very poor stability and this resulted in split peaks by gas chromatography making MBTFA unsuitable for quantitative methods. Quantitation of codeine and morphine using bis-trimethylsilyltrifluoroacetamide (BSTFA/1%TMS) revealed a significant gradual decrease (p less than 0.05) of peak area ratio (PAR) of codeine and morphine compared to the internal standard using selected ion monitoring (SIM). The acetic anhydride derivative showed no significant differences in the peak area ratios for codeine/IS over a period of 24 hours, although the coefficient of variation (CV) was higher for the acetyl derivative than for the TMS derivative of codeine. There was a significant difference associated with the acetyl derivative of morphine at 4 h post derivatization compared to the initial injection (p less than 0.05); however, the acetyl derivative was stable for 24 hours and had a CV of less than 10% at a cutoff of 300 ng/mL.

Acetamides↗
PubMedDate not supplied

High-resolution proton nuclear magnetic resonance spectroscopy in the detection and quantitation of ethanol in human serum.

A precise, accurate, and nondestructive method for the detection and quantitation of serum ethanol in humans using proton (1H) nuclear magnetic resonance spectroscopy (MRS) was developed. The 1H MRS method was linear within the range of 30-1500 mg/L. The lowest detectable ethanol concentration was 15 mg/L, with 30 mg/L being the lowest level reproducibly quantitated. Within-run and day-to-day coefficients of variation (CV) ranged from 0.6 to 2.7% and 0.5 to 3.5%, respectively. The excellent day-to-day CVs indicate a negligible loss of ethanol due to volatilization during analysis. Fifteen human serum samples found to be negative for ethanol by headspace gas chromatography (HSGC) had no ethanol as detected by 1H MRS. Twenty-eight human serum samples with ethanol concentrations (determined by HSGC) ranging from 370 to 4440 mg/L were accurately reproduced by 1H MRS. The 1H MRS method required no pretreatment and was nondestructive, thereby allowing for further analysis by confirmatory methods.

Ethanol↗
PubMedDate not supplied

Glutamine facilitates chemotherapy while reducing toxicity.

Dose intensification of chemotherapy is thought to increase survival. With recent advances in hemopoietic cell modulators such as granulocyte colony stimulating factor, the limiting toxicity of intensifying chemotherapeutic regimens has become the severity of the associated enterocolitis. In animal models, glutamine protects the host from methotrexate-induced enterocolitis. This study evaluates the effects of a glutamine-supplemented diet on the tumoricidal effectiveness of methotrexate. Sarcoma-bearing Fisher 344 rats (n = 30) were pair-fed an isocaloric elemental diet containing 1% glutamine or an isonitrogenous amount of glycine beginning on day 25 of the study. Rats from each group received two intraperitoneal injections of methotrexate (5 mg/kg) or saline on days 26 and 33 of the study. On day 40, rats were killed, tumor volume and weight were recorded, and tumor glutaminase activity and tumor morphometrics were measured. Blood was taken for arterial glutamine content, complete blood count, and blood culture. The gut was processed for glutaminase activity and synthesis phase of the deoxyribonucleic acid. In rats receiving methotrexate, the tumor volume loss was nearly doubled when glutamine was added to the diet. Significant differences in tumor glutaminase activity and morphometrics were not detected. The toxicity to the host was ameliorated. Significantly increased synthesis phase of deoxyribonucleic acid of the whole jejunum, decreased bacteremia, "sepsis," and mortality were demonstrated. Glutamine supplementation enhances the tumoricidal effectiveness of methotrexate while reducing its morbidity and mortality in this sarcoma rat model.

Animals↗
PubMedDate not supplied

Toxicology: past, present, and future.

Toxicology is the study of poisons and poisoning and has an ancient and venerable history. Although there have been numerous notorious poisonings throughout the ages and rather astute descriptions of toxic agents, the scientific study of toxicology did not commence until the 19th century. There was rapid development of analytical methods in the late 19th century and then an acceleration of both method and scientific development in the latter half of the 20th century. Toxicology today can be subdivided into clinical toxicology, forensic toxicology, industrial or occupational toxicology, environmental toxicology, pharmaceutical toxicology, experimental toxicology, and workplace drug testing. The historical development of these overlapping areas of toxicology will be discussed, culminating in a prediction as to what the future may bring.

Environmental Medicine↗
PubMedDate not supplied

Reticulocyte counting by flow cytometry. A comparison with manual methods.

The reticulocyte count (RC) is a key diagnostic test in the evaluation, classification, and response to therapy of anemia. The RC, as determined by manual methods, has a frustrating inherent imprecision owing to its binomial counting statistics (i.e., low counts/low precision) and inaccuracy because of inter- and intraobserver variability as to what indeed is a reticulocyte. Fluorescent activated cytometric (FACS) analysis of reticulocytes by thiazole orange (TO) is a rapid, relatively simple, and precise method for counting reticulocytes. The automated method counts 10,000 cells or more vs. 1,000 cells counted by the manual method. Although inherently more precise, the FACS method may be inaccurate owing to the presence of Howell-Jolly bodies, nucleated red blood cells (RBCs), sickled cells, or giant platelets. The RC by FACS is well correlated with the manual method and the reference ranges are similar. A new parameter by FACS, the reticulocyte maturation index (RMI), provides an independent measurement of reticulocyte RNA content. Although the RMI does not correlate with RC either by FACS or manual methods, it does provide an independent parameter of erythropoietic activity and may be useful in predicting bone marrow engraftment or further subclassifying anemias. Determination by FACS of the RC offers significant advantages over manual methods in monitoring a patients erythropoietic response. However, one must be cognizant of potential pitfalls in the method.

Adult↗
PubMedDate not supplied

Fine needle aspiration in the diagnosis of liver neoplasms: a review.

Fine needle aspiration biopsy (FNAB) for the diagnosis of liver neoplasms is a safe, rapid, and accurate technique. It is most useful in patients with a hepatic mass(es) and a previously diagnosed malignant neoplasm. With the current application of immunocytochemical techniques, accurate cytologic diagnoses can be made in most primary and secondary hepatic neoplasms. The equipment necessary to perform FNAB is simple, inexpensive, and readily available. The principle of this technique is to obtain a representative cellular aspirate via a small bore needle and produce a stained image on a microscopic slide that reflects the disease process in the patients. Techniques and clinical skills of FNAB and experiences of interpretation are required to make maximal use of this diagnostic modality.

Biopsy, Needle↗
PubMedDate not supplied

Lymph node pathology of acquired immunodeficiency syndrome (AIDS).

There has been a recent notable increase in the number of patients in the United States seropositive for the human immunodeficiency virus (HIV) and also an increase in the number of otherwise healthy homosexuals with persistent generalized lymphadenopathy (PGL). Lymphoid tissue appears to be a favorite target for the initial viral infection, subsequent opportunistic infections, and associated neoplasms. Therefore, evaluation of PGL is important in understanding the nature of the disease. Biopsies of the acquired immunodeficiency syndrome (AIDS) lymph nodes show a spectrum of abnormal lymphoid proliferations, eventual lymphoid depletion, Kaposi's sarcoma, and malignant lymphoma. Although the individual features of AIDS-related lymphadenopathy may not be specific, the constellation of histologic, immunologic, ultrastructural, and fine needle aspiration findings is characteristic.

AIDS-Related Complex↗
PubMedDate not supplied

Disopyramide: clinical indications, pharmacokinetics and laboratory assessment.

Disopyramide is an antiarrhythmic drug similar to quinidine and used primarily to treat ventricular ectopic systoles. Unlike quinidine which shows drug-drug interaction with digoxin, disopyramide appears to be free of this problem. Side effects include anticholinergic symptoms, cardiovascular problems, and some gastrointestinal discomfort. Disopyramide is metabolized to N-desisopropyl disopyramide in the liver with approximately 50 percent of the parent drug excreted unchanged. The elimination half-life varies from 4.5 to nine hours, and it can be even longer in cases of renal failure or myocardial infarction. There exists an extremely variable degree of protein binding (10 to 70 percent), which is highly dependent on concentration. The unbound (free) fraction increases with increasing drug concentration, making the interpretation of total disopyramide concentrations very difficult. Since the free drug concentration is more representative of availability to its receptor, and only the free fraction is available for renal excretion, the free drug concentration may represent a better predictor of therapeutic effectiveness. Methods for determining concentrations of disopyramide include gas chromatography, high performance liquid chromatography, homogeneous enzyme immunoassay (EMIT), and fluorescence polarization immunoassay. A method for performing both total and free disopyramide determinations is also described.

Cardiac Complexes, Premature↗