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Biomedical subjects

J R Swanson

Publications and source records attributed to J R Swanson.

At least 19 recordsLinked to original sources
PubMed2001

Screening family members at high risk for coronary disease. Why isn't it done?

BACKGROUND: The National Cholesterol Education Program strongly recommends screening family members of patients with early cardiovascular disease (CVD) for coronary risk factors, but the physician and patient compliance with this recommendation has not been extensively studied. The American College of Cardiology Evaluation of Preventive Therapeutics (ACCEPT) study, a national survey conducted in 1996-1997, determined if physicians were screening first-degree relatives of patients with early CVD. SETTING/PARTICIPANTS: The ACCEPT study included 5553 patients with either their first bypass surgery, first angioplasty, an acute myocardial infarction, or myocardia ischemia, admitted to 53 hospitals throughout the United States. MAIN OUTCOME MEASURE: Self-reported screening of first-degree relatives obtained by interview follow-up 6 months after event. RESULTS: Less than 1% of inpatient medical records contained a discharge plan by the physician recommending screening family members of patients younger than age 55. Only 17.8% of these patients had their family screened within 6 months of their cardiovascular event, while only 19.6% with a recognized family history of premature coronary artery disease had their family screened. The only factors that were significant (p<0. 05) predictors of successful family screening were education (19.4%), having high cholesterol (16.4%), being widowed (18.1%), not smoking (16.4%), and being black (20.5%). CONCLUSIONS: U.S. physicians do not appear to follow national recommendations for the screening of family members of their high-risk patients. These data also suggest that physicians are not ready to use and exploit known genetic factors in treating CVD even as the human genome data become available for clinical use.

Adult↗
PubMed1998

Cutaneous larva migrans associated with water shoe use.

It has been long suspected that footwear is protective against cutaneous larva migrans. This case report describes a woman who developed cutaneous larva migrans despite wearing 'protective' footwear. We forward a hypothesis by which recently popular water shoes may actually be conducive to the development of cutaneous larva migrans rather than having a protective function.

Aged↗
PubMed1997

Death of two subjects due to imipramine and desipramine metabolite accumulation during chronic therapy: a review of the literature and possible mechanisms.

In two unrelated cases, a 7-year-old boy and a 21-year-old woman died suddenly while receiving chronic imipramine therapy. In the boy, concentrations of imipramine were: Left femoral blood 0.5 mg/L, right femoral blood 1.2 mg/L, aorta blood 1.0 mg/L, liver 68 mg/Kg, and for the active metabolite, desipramine, left femoral blood 6.7 mg/L, right femoral blood 9.9 mg/L, aorta blood 8.7 mg/L, liver 400 mg/Kg. In the woman, the imipramine concentrations were: Femoral blood 0.6 mg/L, liver 37 mg/Kg, and of the active metabolite, desipramine, femoral blood 3.74 mg/L, liver 261 mg/Kg. In both cases, the scene investigation strongly indicated that neither individual had ingested an acute overdose. The very high ratios of desmethyl metabolite to parent drug are consistent with this observation. Impaired metabolism due to a genetically determined "slow metabolizer" phenotype of cytochrome CYP2D6, and/or concurrent therapy with phenothiazines, is suggested as a possible mechanism for the apparent fatal accumulation of these tricyclic antidepressants.

Adult↗
PubMed1996

Prospective assessment of presenting serum markers for cardiac risk stratification.

OBJECTIVE: To quantify the association of initial ED serum cardiac markers with the risk for life-threatening events (LEs) or need for lifesaving interventions (LIs) or administration of IV nitroglycerin. METHODS: A prospective, observational study was performed using a cohort of hemodynamically stable, hospitalized patients (age > or = 25 years) presenting with nontraumatic chest discomfort. Patients with ST-segment elevation on their initial ECGs were excluded. Presenting serum samples were assayed for serum myoglobin and creatine kinase-MB isomer (CK-MB) using the Opus and Stratus systems. Target cases were defined as patients having LEs (e.g., cardiogenic shock, ventricular fibrillation, cardiac arrest), requiring LIs (e.g., intubation, cardioversion, pacing, reperfusion therapy), or needing IV nitroglycerin within 48 hours. Manufacturer's thresholds defined abnormal marker levels. Abnormal ECGs were defined using the Brush criteria. RESULTS: Of the 178 eligible patients, 44 (25%) were target cases. Most (55%) target cases had blood drawn for assays within four hours of chest discomfort onset. The relative risk and sensitivity of the serum markers and the ECG for target cases follow: [table: see text] Of the seven patients with an LE/LI, six had blood drawn four hours or less after symptom onset; two LE/LI patients had abnormal myoglobin levels--no LE/LI patient had an abnormal CK-MB level. CONCLUSIONS: Isolated serum myoglobin and CK-MB levels obtained at patient ED presentation were not strongly associated with the 48-hour risk for LEs, LIs, or the use of IV nitroglycerin. Future studies of risk stratification should address the merits of serial serum marker measurements that extend up to 12 hours beyond patient symptom onset.

Adult↗
PubMed1994

An acetonitrile-related death.

A 39-year-old female who lived alone was discovered dead in her home. An autopsy produced no cause of death. The blood sedative screen was negative and only diphenhydramine was found by the urine organic base analysis. Examination of the blood and urine for volatiles produced an unexpected peak by GC analysis, which was then identified as acetonitrile by GC/MS. Acetonitrile concentrations were 31 and 56 mg/dL in two separate blood samples and 44 mg/dL in the urine. The blood cyanide concentration was 4.4 micrograms/mL. The cause of death was determined to be acetonitrile poisoning although the source of the acetonitrile was not discovered.

Acetonitriles↗
PubMed1993

The specificity of human spermatozoa/zona pellucida interaction under hemizona assay conditions.

The objective of this prospective study was to evaluate the specificity of human sperm/zona pellucida interaction under hemizona assay (HZA) conditions in experiments with gametes from the same and different species. Human, cynomolgus monkey and hamster oocytes were used after salt-storage. Oocytes were bisected into matching hemizonae by micromanipulation and used in the HZA. Semen was obtained from healthy men (donors) and male cynomolgus monkeys and prepared by wash and swim-up. Sperm binding to matching hemizonae was assessed (tight binding) after 4-h coincubation in the HZA in homologous and interspecies experiments. Acrosome reaction was evaluated in the sperm droplets using FITC-PSA and on the hemizonae using the T-6 monoclonal antibody. On human hemizonae, the number of tightly bound sperm for human and monkey were 93.2 +/- 15.8 and 3.9 +/- 1.3, respectively (P < 0.001). On monkey hemizonae, the number of tightly bound sperm for monkey and human were 126.0 +/- 34.8 and 2.8 +/- 1.6, (P = 0.02) respectively. On hamster hemizonae, there was negligible binding of human and monkey sperm. There was a significantly higher incidence of acrosome reacted sperm on the zona pellucida in homologous compared to heterologous experiments. These results demonstrate a high species-specificity of human gamete functions under HZA conditions, providing further support for the use of this bioassay in infertility and contraception testing.

Acrosome↗
PubMed1992

Serial ECGs are less accurate than serial CK-MB results for emergency department diagnosis of myocardial infarction.

HYPOTHESIS: Serial creatine kinase-MB (CK-MB) levels provide more accurate predictive information regarding myocardial infarction than serial ECGs in emergency department patients with chest discomfort and no ST-segment elevation on the initial ECG. DESIGN: Prospective, observational study. SETTING: University hospital and university-affiliated Veterans Affairs Medical Center EDs. PARTICIPANTS: Two hundred sixty-one patients 30 years or older with chest discomfort warranting an ECG and consenting to observation. Exclusions included hemodynamic or rhythm instability and ST-segment elevation of 0.1 mV or more in two or more electrically contiguous leads at presentation. MEASUREMENTS: ECGs were obtained at presentation and three to four hours after presentation. Significant serial ECG changes sought on comparison of initial and three- to four-hour ECGs were 0.05 mV or more ST elevation or depression, Q-wave development, or T-wave inversion changes in two or more electrically contiguous leads. CK-MB levels were obtained at presentation and hourly for three hours (positive level, 8 or more ng/mL). Myocardial infarction was determined by record review and was based on independent CK-MB measurements. RESULTS: Twenty-eight (11%) patients were diagnosed with a myocardial infarction. Thirty-eight (15%) patients had a serial ECG change. Eleven of the myocardial infarction patients (39%) had a serial ECG change compared with 27 (12%) of the non-myocardial infarction patients (P < .001). Sensitivities and specificities of a serial ECG change versus serial CK-MBs for myocardial infarction were 39% versus 68% (sensitivity) and 88% versus 95% (specificity), respectively. Serial CK-MBs were more accurate than a serial ECG change for predicting myocardial infarction (P < .03). CONCLUSION: Serial changes in ECGs during a three- to four-hour interval were associated with the diagnosis of myocardial infarction but were infrequent and less accurate than serial CK-MB levels obtained for the same interval.

Adult↗
PubMed1991

The immunogenicity and safety of intradermal hepatitis B vaccine.

BACKGROUND: One of the chief barriers to a greater use of hepatitis B vaccine is the high cost of the vaccine itself. A number of small research trials have shown that an adequate immune response can be induced at a much lower cost by administering one tenth of the vaccine using an intradermal technique. The purpose of this study was to ascertain whether these results could be replicated in a larger clinical trial. METHODS: Vaccine recipients included health care providers, police officers, and firefighters. Recipients were given 0.1 mL of plasma-derived hepatitis B vaccine intradermally on days 1, 30, and 180. Antibody response was measured on day 210, with seroconversion defined as a sample-to-negative (S/N) ratio of greater than or equal to 10. Any local and systemic side effects were documented. RESULTS: Six hundred sixteen individuals completed the vaccination series, and seroconversion occurred in 534 (86.7%). The rate of seroconversion in those younger than 40 years was 91.2% and in those 40 years and older was 75.1%. The mean S/N ratio was 154.9 (range 0 to 620) and decreased with increasing age (r = -.25, P = .0001). Side effects were largely limited to local reactions. CONCLUSIONS: The results support the use of the intradermal technique as a cost-effective alternative to the intramuscular route in individuals younger than 40 years. The intradermal technique may be used in older individuals if titers are obtained to assure seroconversion. Because of the restricted availability of the plasma-derived vaccine used in this study, similar trials with recombinant vaccine should be undertaken.

Adolescent↗
PubMed1989

Cyclosporine determinations in heart and kidney transplant patients: comparison of high-performance liquid chromatography, polyclonal, and monoclonal methods.

We have analyzed and compared the cyclosporine concentrations in whole blood specimens from heart and kidney transplant patients, using three different methods: high-performance liquid chromatography (HPLC), polyclonal radioimmunoassay, and monoclonal radioimmunoassay. HPLC results for heart transplant patients correlated well with the monoclonal (specific antibody) results but did not correlate with the polyclonal (nonspecific antibody) results. All three methods correlated well for renal transplant patients; however, polyclonal results were consistently higher than either monoclonal or HPLC results. We conclude that the results from the monoclonal (specific antibody) RIA are equivalent to HPLC results for both kidney and heart transplant patients.

Chromatography, High Pressure Liquid↗
PubMed1989

Massive levothyroxine ingestion. Conservative management.

The clinical course of a 29-month-old girl who was referred for evaluation after ingesting ninety 0.2-mg tablets of levothyroxine is reported. Despite an initial thyroxine (T4) level of 282 micrograms/dl and a triiodothyronine (T3) level of 1,837 ng/dl at 48 hours postingestion, her symptoms were mild and included irritability, vomiting, tremor, and tachycardia. Treatment was limited to activated charcoal and propranolol. Thyroid hormone levels fell to normal by 13 days postingestion. The child's clinical course was benign. Even after massive acute ingestions of levothyroxine, children's symptoms are usually mild and may be controlled with propranolol. This conservative approach should be considered before expensive and potentially dangerous therapies are undertaken.

Charcoal↗
PubMed1989

Multicenter evaluation of TDx test for assessing fetal lung maturity.

"TDx Fetal Lung Maturity," an automated assay that measures the relative concentrations of surfactant and albumin in amniotic fluid, was compared with the lecithin/sphingomyelin (L/S) ratio and phosphatidylglycerol determination at five clinical sites. A total of 695 amniotic fluid samples were analyzed, of which 312 were followed by delivery of the infant within three days of sample collection. Of these 312, 24 developed respiratory distress syndrome and seven developed transient tachypnea. With the cutoff for maturity set at a surfactant/albumin value of 50 mg/g, the assay showed a sensitivity of 0.96 and a specificity of 0.88 for all samples, compared with a sensitivity of 0.96 and a specificity of 0.83 for the L/S ratio. The combination of rapid assay (30 min), accurate results, and uniformity among testing centers makes the TDx assay a very promising method.

Albumins↗
PubMed1987

Effect of albumin and lamellar bodies on fluorescence polarization of amniotic fluid.

Using a probe and procedure developed for the Abbott TDx analyzer, we investigated the influence of albumin on fluorescence polarization of amniotic fluid. Polarization readings increased when albumin was added to either "mature" or "immature" amniotic fluids. Albumin added to a fraction rich in lamellar bodies (10,000 X g pellet) greatly increased polarization readings, but albumin added to the lamellar-body-free fraction resulted in only small increases. Adding increasing amounts of the lamellar-body-rich fraction from mature and immature pools to a constant amount of albumin decreased the polarization readings. We saw no correlation between amniotic fluid polarization and albumin concentration but found a significant correlation between polarization values and either total extractable phospholipids (r = 0.725, P less than 0.001) or the ratio albumin/total extractable phospholipids (r = 0.784, P less than 0.001). The concentration of albumin in amniotic fluid was variable and correlated poorly with gestational age.

Albumins↗
PubMed1987

Modified lamellar body phospholipid assay compared with L/S ratio and phosphatidylglycerol assay for assessment of fetal pulmonary status.

We used a modified lamellar body phospholipid (LB-PL) assay to evaluate the effect of sample processing and to evaluate the clinical efficacy of LB-PL determinations. Within-run and between-run CVs for the modified LB-PL assay respectively ranged from 2.9 to 6.7% and from 3.4 to 14.3%. Freezing and storage at -20 degrees C did not affect results for LB-PL (n = 12). Statistically significant amounts of lamellar bodies were lost on centrifugation, ranging from 20% at 150 X g to 54% at 1000 X g for 5 min. The LB-PL content, lecithin/sphingomyelin ratio, and phosphatidylglycerol content of 194 samples of amniotic fluid obtained within three days of delivery were compared for the assessment of fetal pulmonary maturity. Twenty-three neonates developed respiratory problems at or shortly after birth. With uncontaminated samples (n = 160), the LB-PL assay exhibited better specificity than the lecithin/sphingomyelin ratio (p less than 0.01, Chi square) or the phosphatidylglycerol assay (p less than 0.001, Chi square) for samples obtained after 36 weeks of gestation. Assay sensitivities did not differ significantly. Differences among assay predictive values were not significant.

Amniotic Fluid↗
PubMed1986

Mid-molecule parathyroid hormone assay comparison.

Parathyroid hormone (PTH) assays are becoming available to clinical chemistry laboratories for in-house use. We evaluated the clinical utility of two mid-molecule PTH assays in comparison to a sensitive but technically demanding component assay. A normal reference population, and an abnormal population including cases of primary and secondary hyperparathyroidism, hypoparathyroidism, and humoral hypercalcemia of malignancy were tested. PTH determinations with each assay system and total serum calcium determinations were done on all specimens. The Endocrine Metabolic Center (EMC) kit assay and the Immuno Nuclear Corp. (INC) kit assay demonstrated adequate standard curve reproducibility and precision for clinical use. With the aid of calcium determinations each assay performed well in the separation of abnormal patient groups, and in the separation of abnormal from normal PTH-calcium homeostasis. PTH values for the reference population differed among the three assays. The component assay and the EMC assay had a negative correlation with serum calcium, but the INC assay had a positive correlation with serum calcium.

Calcium↗