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Biomedical subjects

E Peterson

Publications and source records attributed to E Peterson.

At least 91 records · Page 5Linked to original sources
PubMed1989

Comparison of monoclonal antibodies for rapid detection of cytomegalovirus in spin-amplified plate cultures.

Cytomegalovirus (CMV) was detected in 56 of 275 specimens (20%); 50 of 56 (89%) were detected by conventional culture, and 37 (66%) were detected by rapid assay at 72 h with a commercial monoclonal antibody and a pooled monoclonal antibody. Although the two antibodies were equally sensitive at 72 h, the pooled antibody gave a brighter, more easily detected signal. Other viruses were isolated from 9 specimens (3.3%) by conventional culture. Use of rapid assays alone fails to detect slow-growing CMV and non-CMV viral pathogens.

Antibodies, Monoclonal↗
PubMed1989

Relationship of bioelectrical impedance to pharmacokinetic parameters of theophylline in healthy males.

Bioelectrical impedance is a reliable, safe, non-invasive and valid method of determining body composition, using measures of resistance and reactance by passing a low voltage alternating current through the body. This study investigates relationships between the pharmacokinetics of theophylline and parameters of bioelectrical impedance in 15 non-smoking, healthy, adult male volunteers. After an overnight fast, subjects received 5 mg/kg of aminophylline intravenously over 30 minutes. Blood samples were obtained serially over a period of 12 hours. Bioelectrical impedance measurements were made in triplicate, using a 4-electrode plethysmograph. Sera were assayed in duplicate by enzyme-mediated immunoassay (coefficient of variation less than 5%), and data were fitted to a non-compartmental regression program. An all-subsets multiple-regression technique was employed to arrive at predictive equations for theophylline clearance (CL) and volume of distribution at steady-state (Vss) using age, height, weight and mean bioelectrical impedance parameters. Equations for Vss and CL revealed p-values of less than 0.001 and coefficients of variation of 8.5 and 13.33% respectively. Although the equations display some degree of colinearity they account for 95 and 86.5% of the variability in Vss and CL respectively, and represent an innovative approach to the estimation of pharmacokinetic parameters.

Adult↗
PubMed1988

Frequency and significance of cardiac arrhythmias in chronic obstructive lung disease.

Ambulatory electrocardiograms obtained in 69 patients enrolled in the nocturnal oxygen therapy trial group were examined for frequency and significance of arrhythmias in patients with stable chronic obstructive lung disease. Ventricular premature beats occurred in 83 percent, ventricular bigeminy in 68 percent, paired ventricular premature beats in 61 percent, and nonsustained ventricular tachycardia in 22 percent of the patients. Supraventricular tachycardia occurred in 69 percent. Repetitive ventricular arrhythmia occurred in 64 percent of the patients, and was significantly more frequent in men and in patients with edema or elevated PCO2. Ventricular premature beats greater or equal to 25 per hour occurred in 35 percent of the patients. Univariate and multivariate Cox proportional hazards analysis showed that a history of coronary heart disease, increased sinus heart rate and decreased maximum work load (measured by maximal treadmill exercise test)--but not arrhythmias--were predictors of death.

Aged↗
PubMed1987

Mixed venous oxygen saturation as a predictor of cardiac output in the postoperative cardiac surgical patient.

Mixed venous oxygen saturation (SvO2) was measured continuously with a fiberoptic pulmonary artery catheter in 25 patients during the first 24 hours after cardiac surgery and was compared with the thermodilution cardiac index (CI). The mean correlation coefficient between SvO2 and CI was 0.05 +/- 0.42, and was not significantly different from zero. Although the mean correlation coefficient between the change in SvO2 and the change in CI was significant (p less than .05), the magnitude of the coefficient (0.19 +/- 0.44) indicates poor predictive value. The correlation did not improve when adjusted for multiple clinical variables, and the SvO2 was not predictive of a CI less than 2 L/min/m2, a level of cardiac performance that might require intervention. In conclusion, SvO2 was not predictive of CI postoperatively in the cardiac surgical patient.

Blood Gas Monitoring, Transcutaneous↗
PubMed1987

Asynchronous primary valve failure in patients with porcine bioprosthetic aortic and mitral valves.

Seventy-three patients with aortic and mitral porcine bioprosthetic valves (PBV) have been followed for up to 14 1/2 years. In that time, 11 patients have undergone replacement of one or more PBVs for primary tissue failure. Three patients underwent repeat aortic and mitral valve replacement for synchronous PBV failure. Two patients underwent aortic valve replacement alone and six had only the mitral PBV replaced. The one survivor of the repeat aortic valve replacement has a normally functioning mitral PBV, which has now been in place for 48 months. The six patients who had their mitral PBVs replaced have normally functioning aortic PBVs that have now been in place for periods from 96 to 176 months. Our experience shows that with asynchronous PBV failure only the dysfunctioning valve needs to be replaced. Prophylactic PBV replacement is not warranted if the prosthesis demonstrates normal hemodynamics on cardiac catheterization and normal structure on the echocardiogram, regardless of the length of time it has been implanted.

Actuarial Analysis↗
PubMed1986

Effectivity of dolichyl phosphates with different chain lengths as acceptors of nucleotide activated sugars.

Chemical synthesis of different S-forms of dolichyl-P was performed in order to investigate the use of these polyprenes in mannosyl, glucosyl and glucosaminyl transferase reactions. Determination of the Vmax values for a series of dolichyl-P demonstrated that the velocities of transferase reactions with all those dolichyl-P derivatives present in animal tissues are largely the same. The apparent Km values for the various dolichyl-P in the transferase system studied differed, but this property does not appear to have physiological importance.

Animals↗
PubMed1985

Reaction of optically active S- and R-forms of dolichyl phosphates with activated sugars.

Chemical synthesis was used to produce optically active isomers of dolichol (S- and R-forms) with 18 and 19 isoprene residues. The phosphorylated polyprene was studied in rat liver microsomal GDP-mannosyl and UDP-N-acetylglucosaminyl transferase systems. The two dolichol-P forms in both transferase systems gave Vmax values which for the S-form exceeded 4-6 times what was obtained with the R-form. The Km values were also higher for the S-form. The hepatocyte appears to contain a large excess of dolichyl-P, by 100 times exceeding that of the Km values. For this reason the S-form of dolichyl-P seems to be one of the requirements for the normal establishment of the N-glycosidically linked oligosaccharide chain.

Animals↗
PubMed1985

Prophylactic lymphadenectomy for B16 melanoma in C57/BL6 mice: survival based on size and heterogeneous variant of the primary.

Survival following prophylactic lymphadenectomy by hip disarticulation in mice with three B16 melanoma variants was studied. C57/BL6 mice inoculated with viable tumor cells (F1, F10, and BL6) into the left hind foot pad were randomized to wide excision (WE) of the primary tumor alone or wide excision plus prophylactic lymphadenectomy (WE plus PL) at 1-, 2-, 3-, 4-, and 5-mm primary tumor sizes (each group, N = 6). Overall survival time was improved by WE plus PL. A significant survival advantage and cure was apparent for the F1 and F10 variants with primary tumor sizes of 2 and 3 mm (F1, 2 and 3 mm, P less than 0.001; F10, 2 mm, P less than 0.006; 3 mm, P less than 0.001), but not for the BL6 variant. Prophylactic lymphadenectomy provides a therapeutic advantage in mouse melanomas of intermediate size in two of the three variants of B16.

Animals↗
PubMed1985

Pathogenicity, stability, and immunogenicity of a knobless clone of Plasmodium falciparum in Colombian owl monkeys.

The pathogenicity, immunogenicity, and morphological stability of a knobless clone of strain FCR-3 of the human malaria parasite Plasmodium falciparum was investigated in Aotus monkeys. An early knob-bearing (K+), wild-type isolate of strain FCR-3 and the D3 knobless (K-) clone were adapted to Aotus monkey erythrocytes in continuous culture, establishing the parasites in Aotus cells without exposure to in vivo cellular or humoral immune responses. All monkeys, intact or splenectomized, which were infected with wild-type FCR-3 adapted to Aotus cells in vitro, developed virulent infections and had to be drug treated. The intact nonsplenectomized animals which received knobless D3 cloned parasites did not develop virulent infections even after multiple infections. The splenectomized monkeys which received the K- D3 clone had virulent infections. Late-stage wild-type K+ parasites sequestered in both intact and splenectomized monkeys, whereas late-stage D3 K- parasites did not sequester in the splenectomized animals. These results suggest that two elements affected the pathogenicity of the malaria parasites in these experiments. Knobs on K+-infected erythrocytes enabled these parasites to sequester, presumably by attachment to capillary endothelium. When present, the spleen eliminated circulating K- late-stage erythrocytes, presumably by selection on the basis of their nondeformability. Although clone D3 K- parasites are nonvirulent in intact monkeys, they induced some immunological protection against challenge with wild-type K+ parasites. The surface morphology of K--infected erythrocytes remains unaltered throughout these experiments, suggesting that loss of knobs is a stable condition.

Animals↗
PubMed1985

The porcine bioprosthetic valve. Twelve years later.

The porcine bioprosthetic heart valve has been commercially available since 1970 and has been the prosthetic heart valve of choice in our institution since 1971. Since that time 817 patients with 951 porcine valves have been discharged from the hospital and were available for long-term follow-up. Patient survival rates, with operative mortality excluded, were 80% +/- 1.7% (standard error) at 5 years and 68% +/- 2.7% at 10 years. Survival rates for patients with aortic valve prostheses were 78% +/- 2.8% at 5 years and 57% +/- 5.4% at 10 years; for patients with mitral valve prostheses, survival rates were 80% +/- 2.2% at 5 years and 69% +/- 3.2% at 10 years. Freedom from thromboembolism for aortic valves was 93% +/- 1.4% at 5 years and 88% +/- 2.6% at 10 years; for mitral valves the freedom from degeneration or primary tissue failure for aortic valves was 97% +/- 1.3% at 5 years and 71% +/- 7.6% at 10 years; for mitral valves these figures were 96% +/- 1.2% at 5 years and 71% +/- 4.1% at 10 years. Valves in patients 35 years of age and below had a significantly greater rate of degeneration (p less than 0.001). After 12 years' experience the porcine bioprosthetic valve has performed well with regard to patient survival and low rate of thromboembolism. For patients older than 35 years the freedom from primary tissue failure is 80% at 10 years.

Adolescent↗
PubMed1984

Cisplatin plus cytosine arabinoside in adults with malignant gliomas.

A combination of cisplatin and cytosine arabinoside was used to treat 21 patients with glioblastomas and 5 patients with recurrent grade II gliomas. Cisplatin 60-100 mg/m2 was given I.V. in 250 ml 0.45% saline and preceded by 500 ml dextrose 5% in 0.45% saline. Mannitol 50 g was given I.V. concurrently with the cisplatin. Cytosine arabinoside 500-1000 mg/m2 was given by rapid I.V. infusion immediately after the cisplatin. Of 25 evaluable patients, 10 (40%) experienced objective tumor shrinkage on CT scan, and 6 (24%) stabilized. There were 2 complete remissions. Patients who had had no prior treatment had a higher response rate (58%) than those previously treated (23%). Myelosuppression occurred in some patients 2-3 weeks after treatment. Gastrointestinal toxicity (vomiting and diarrhea) was dose-limiting. Two patients had possible neurological toxicity. Recommended doses for further studies are cisplatin 90 mg/m2 and cytosine arabinoside 900 mg/m2.

Adult↗
PubMed1984

Treatment of malignant gliomas in adults with BCNU plus metronidazole.

Twenty-six adult patients with astrocytomas were treated with BCNU (1,3-bis(2-chloroethyl)-1-nitrosourea) 180-240 mg/m2 I.V. every 6-9 weeks, with metronidazole 1.5 g/m2 p.o. 12 h and 1 h before BCNU and again 6 h and 24 h after BCNU. Of twenty-two evaluable patients, 9 (41%) responded with evidence of reduced tumor size on CT scan, 3 (14%) stabilized and 10 (45%) failed. Patients with no prior chemotherapy or radiotherapy, good performance status, low grade tumors, and age less than or equal to 50 years had the highest response rates, although differences were not statistically significant. Median survival and duration of response have not been reached with a median follow-up time of ten months. Hematological toxicity was dose-limiting and was probably not augmented by the metronidazole. There was one death from infection that was possibly drug-related. Gastrointestinal toxicity was substantial, and was probably increased by the metronidazole. While the combination of BCNU and metronidazole were tolerable, the response rate seen was no higher than that noted for BCNU alone, and further studies using this dose-schedule are not recommended in astrocytomas.

Adult↗
PubMed1984

Occurrence of hepatitis A, B, and non-A/non-B in the United States. CDC sentinel county hepatitis study I.

To determine the relative occurrence of hepatitis A, B, and non-A/non-B in the United States, serum samples and epidemiologic data were collected from patients with hepatitis in five selected counties. Overall, 41, 33, and 26 percent of the patients had hepatitis A, hepatitis B, and hepatitis non-A/non-B, respectively. The incidence, especially of hepatitis A, varied considerably. All three types of hepatitis occurred more frequently in those 15 to 44 years of age. Hepatitis A predominated in those less than 15 years of age and non-A/non-B predominated in those older than 44 years. There was a male predominance (65 to 62 percent) for hepatitis A and hepatitis B, but non-A/non-B occurred equally in both sexes. There was no seasonal pattern for any type. Risk factors for hepatitis A were previous contact with a patient with hepatitis (26 percent), homosexual (male) preference (15 percent), and day-care center contact (11 percent). For hepatitis B, risk factors included drug use (26 percent), previous contact with an infected person (22 percent), homosexual preference (12 percent), and a health-care occupation (12 percent). For hepatitis non-A/non-B, risk factors included drug use (16 percent), transfusion (12 percent), and previous contact with an infected person (12 percent). Previous hospitalization appeared to be a risk factor for both hepatitis B and hepatitis non-A/non-B.

Adolescent↗