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Biomedical subjects

R McFadden

Publications and source records attributed to R McFadden.

10 recordsLinked to original sources
PubMed2000

Effect of transjugular intrahepatic portosystemic shunt on thrombocytopenia associated with cirrhosis.

Thrombocytopenia is a frequent complication of cirrhosis. Its pathogenesis is not well known, but it has been suggested that splenic congestion induced by portal hypertension may be a major contributory factor. However, the available data regarding the effect of portal decompression either by surgical shunts or transjugular intrahepatic portosystemic shunt (TIPS) on peripheral platelet count in cirrhotics is conflicting. We studied the effects of TIPS on platelet count and mean platelet volume, following a successful TIPS placement. The platelet count had a tendency to decrease but was not statistically significant (120,100 +/- 72,100/mm3 before TIPS vs 99,800 +/- 51,400/mm3 after TIPS). The mean platelet volume remained essentially unchanged (9.8 +/- 1.5 fL before TIPS and 9.9 +/- 1.5 fL after TIPS). These results confirm that TIPS has an unpredictable effect on platelet count in cirrhotic patients with thrombocytopenia. The lack of a consistent increase in the peripheral mean platelet volume following TIPS placement suggests that TIPS is unable to significantly enhance the release of platelets sequestered in the splenic compartment in portal hypertension.

Adult↗
PubMed1996

Side effects associated with influenza vaccination in healthy working adults. A randomized, placebo-controlled trial.

BACKGROUND: Concern about side effects is a barrier to influenza vaccination. This randomized, double-blind, placebo-controlled trial assessed side effects following vaccination among healthy working adults. METHODS: Healthy working adults were recruited during October and November 1994 and were randomized to receive influenza vaccine or placebo injections. Local and systemic symptoms during the week following the injection were evaluated through structured telephone interviews. RESULTS: Of 849 subjects enrolled in the study, 425 received a placebo and 424 received influenza vaccine. Baseline characteristics were similar between the groups, and 99% of subjects completed interviews to assess side effects after the study injection. No differences were seen between the 2 groups for the systemic symptoms of fever, myalgias, fatigue, malaise, or headaches. Overall, 35.2% of placebo and 34.1% of vaccine recipients reported at least 1 of these systemic symptoms (P = .78, chi 2). Vaccine recipients reported a higher rate of arm soreness at the injection site than did placebo recipients (63.8% vs 24.1%, P < .001). Local reactions were mild in both groups and infrequently resulted in decreased use of the arm. After logistic regression, female sex (odds ratio [OR], 1.5;95% confidence interval [CI], 1.1-2.1), age younger than 40 years (OR, 1.6;95% CI, 1.2-2.2), and coincidental upper respiratory tract illness (OR, 4.6; 95% CI, 3.2-6.6) were independently associated with higher rates of systemic symptoms. In the multivariate model, vaccine again was not associated with systemic symptoms (OR, 0.9; 95% CI, 0.7-1.2). CONCLUSIONS: Influenza vaccination of healthy working adults is not associated with higher rates of systemic symptoms when compared with placebo injection. These findings should be useful to physicians and other health care providers as they counsel patients to take advantage of an important opportunity for disease prevention and health protection.

Adult↗
PubMed1995

The effectiveness of vaccination against influenza in healthy, working adults.

BACKGROUND: Although influenza causes substantial morbidity and mortality in all age groups, current recommendations emphasize annual immunization for people at high risk for complications of influenza. We conducted a double-blind, placebo-controlled trial of vaccination against influenza in healthy, working adults. METHODS: In the fall of 1994, we recruited working adults from 18 to 64 years of age from in and around the Minneapolis-St. Paul area and randomly assigned them to receive either influenza vaccine or placebo injections. The primary study outcomes included upper respiratory illnesses, absenteeism from work because of upper respiratory illnesses, and visits to physicians' offices for upper respiratory illnesses. The economic benefits of vaccination were analyzed by estimating the direct and indirect costs associated with immunization and with upper respiratory illnesses. RESULTS: We enrolled a total of 849 subjects. Baseline characteristics were similar in the two groups. During the follow-up period, consisting of the 1994-1995 influenza season (December 1, 1994, through March 31, 1995), those who received the vaccine reported 25 percent fewer episodes of upper respiratory illness than those who received the placebo (105 vs. 140 episodes per 100 subjects, P < 0.001), 43 percent fewer days of sick leave from work due to upper respiratory illness (70 vs. 122 days per 100 subjects, P = 0.001), and 44 percent fewer visits to physicians' offices for upper respiratory illnesses (31 vs. 55 visits per 100 subjects, P = 0.004). The cost savings were estimated to be $46.85 per person vaccinated. CONCLUSIONS: Vaccination against influenza has substantial health-related and economic benefits for healthy, working adults.

Adolescent↗
PubMed1994

Parental and medical over-administration of acetaminophen causing lethal hepatotoxicity in a 10-year-old.

A 10-year-old girl with acute influenza B virus disease was given repetitive doses of acetaminophen by her mother to reduce the child's fever. When finally seen by trained medical personnel, the child was experiencing abdominal pain, nausea, and vomiting, which are classic signs of acetaminophen hepatotoxicity. Despite these findings, the child was given additional acetaminophen and experienced lethal hepatotoxicity.

Acetaminophen↗
PubMed1988

Mathematical model of simultaneous diffusion and binding of antitumor antibodies in multicellular human tumor spheroids.

Multicellular tumor spheroids are widely used as in vitro models of poorly vascularized tumor nodules in vivo. The uptake kinetics of tumor-associated antibodies in multicellular tumor spheroids is assumed to be governed by passive diffusion and irreversible binding of the antibodies with binding sites on the cell surface. By further assuming that the spheroids are homogeneous with respect to diffusion and binding, a mathematical model has been developed which permits the extraction of the macroscopic diffusion constant D and the macroscopic binding rate k from empirical studies. The model was applied to uptake kinetics data obtained (a) with a melanoma-associated monoclonal antibody 96.5 (isotype IgG2a)-human multicellular melanoma spheroid system exhibiting strong antibody to cell binding and (b) with the same monoclonal antibody-human multicellular colon adenocarcinoma HT29 spheroid system exhibiting nonspecific binding. The spheroids had approximately 300 microns diameter. The constants D and k were estimated to be 0.45 micron2 s-1 and 2.0 x 10(-3) s-1, respectively, for the system with specific binding. Saturation of binding sites occurred. In the nonspecific binding system, D and k were found to be 0.10 micron2 s-1 and 1.0 x 10(-5) s-1. No saturation of binding sites occurred. D and k were also estimated to be, respectively, 0.52 micron2 s-1 and 6.4 x 10(-5) s-1 for another melanoma-associated monoclonal antibody 140.240 (same isotype as 96.5) in the melanoma spheroid system exhibiting moderate cell binding with the antibody. The mathematical model describes well the system exhibiting nonspecific binding, but requires modifications and further development for the systems exhibiting moderate to strong binding.

Adenocarcinoma↗
PubMed1986

The spectrum of liver disease in the acquired immunodeficiency syndrome.

Abnormal liver chemistries, unexplained fevers, or hepatomegaly prompted 36 liver biopsies on 34 patients with the acquired immunodeficiency syndrome. The most common finding was the presence of hepatic granulomas, seen in 13 of the biopsy specimens. Eight of these granulomas were ill-defined, and 5 were more clearly associated with mycobacterial disease. Portal fibrosis and fatty infiltration were common, but a paucity of significant inflammatory activity was seen despite elevated aspartate aminotransferase levels, perhaps related to the underlying immunoincompetent status. Other noteworthy histopathologic findings included 1 patient each with peliosis hepatis and cryptococcal hepatitis. Electron-microscopic evidence of cytoplasmic tubular structures or viral particles were seen within the hepatocytes of 2 patients. It is concluded that a broad spectrum of hepatic histopathology may be seen in the acquired immunodeficiency syndrome, and that liver biopsy may be diagnostically valuable in the clinical investigation of such patients.

Acquired Immunodeficiency Syndrome↗