PubMed Health⌕ Search

Biomedical subjects

A E Ross

Publications and source records attributed to A E Ross.

At least 19 recordsLinked to original sources
PubMed2001

Gender specific sympathetic and hemorrheological responses to mental stress in healthy young subjects.

OBJECTIVE: Activation of the sympathetic nervous system may increase hematocrit (Hct), whole blood viscosity (WBV), and possibly cardiovascular risk. The aim was to study gender specific differences of mental stress on sympathetic reactivity and blood rheology. METHODS: Responses in blood pressure, heart rate (HR), Hct, WBV (Bohlin rotational viscosimeter), and plasma catecholamines to a mental arithmetic stress test (MST) were measured in male (n = 10, 23 +/- 3 years, BMI 23 +/- 2 kg/m2) and female (n = 10, 21 +/- 4 years, BMI 24 +/- 2 kg/m2) students. RESULTS: Systolic blood pressure (SBP), diastolic blood pressure (DBP), and HR increased during MST in men and women, and declined to baseline levels after 15 min of recovery. In men, plasma adrenaline increased by 217% during MST (p < 0.01, ANOVA). and plasma noradrenaline increased by 68% (p < 0.05). Hct and WBV at low shear rates (0.5 and 1.1 l/s) increased as well (p < 0.001, p < 0.05, and p < 0.05, respectively). In women, the increase in plasma adrenaline averaged 118% during MST (p < 0.05) while plasma noradrenaline (-3%, p = 0.38), Hct, and WBV at all shear rates remained unchanged. Men and women differed in A adrenaline (p < 0.05), A noradrenaline (p = 0.01), delta Hct (p < 0.05), and delta WBV (p < 0.05). A Hct tended to correlate with delta SBP (r= 0.60, p = 0.07), A DBP (r = 0.57. p = 0.09). and delta HR (r = 0.50, p = 0.14), and correlated significantly with A noradrenaline (r = 0.66, p < 0.05) in men only. Multiple regression analysis showed that gender independently explained 22% of the change in Hct during mental stress. CONCLUSION: Data suggest gender specific differences in sympathetic and hemorrheological responses to mental stress in healthy young subjects. In men, sympathetic responses were related to hemorrheological responses, but not in women. It may be speculated whether such differences in stress responses may contribute to lower cardiovascular risk in premenopausal women than in men.

Adult↗
PubMed1998

American health care.

Explore the source record for details and available documents.

Deductibles and Coinsurance↗
PubMed1995

Bloodstream invasion in early Lyme disease: results from a prospective, controlled, blinded study using the polymerase chain reaction.

PURPOSE: The purposes of this study were to determine (1) the optimal techniques for and potential diagnostic usefulness of the polymerase chain reaction (PCR) in early Lyme disease, and (2) the true frequency and clinical correlates of PCR-documented blood-borne infection in the dissemination of Lyme disease. PATIENTS AND METHODS: We performed a prospective, controlled, blinded study of PCR, culture, and serology on fractionated blood samples from 105 patients; 76 with physician-diagnosed erythema migrans and 29 controls. Clinical characteristics of the patients were obtained with a standardized data entry form and correlated with results of the laboratory studies. RESULTS: Only 4 of the 76 (5.3%) patients with erythema migrans were culture positive; however, 14 of 76 (18.4%) had spirochetemia documented by PCR of their plasma. None of 29 controls were PCR or culture positive (P = 0.007, versus patients). PCR-documented spirochetemia correlated with clinical evidence of disseminated disease; 10 of 33 patients (30.3%) with systemic symptom(s) were PCR positive compared to 4 of 43 (9.3%) without such evidence (P = 0.02). PCR positivity was more frequent among patients with each of four specific symptoms: fever, arthralgia, myalgia, and headache (all P < 0.05). A higher total number of symptoms (median 2.5 in PCR-positive patients versus 0 in PCR-negative controls; P < 0.01) and the presence of multiple skin lesions (37.5% of patients with multiple, versus 13.3% of patients with single lesions [P = 0.04] were also correlated with PCR positivity. Patients with both systemic symptoms and multiple skin lesions had a 40% PCR-positivity rate; however, 4 of 42 (9.5%) asympatomatic patients with only single erythema migrans lesions were also PCR positive. In multivariate analysis using logistic regression, the number of systemic symptoms was the strongest independent predictor of PCR positivity (P = 0.004). CONCLUSIONS: PCR detection of Borrelia burgdorferi is at least three times more sensitive than culture for identifying spirochetemia in early Lyme disease and may be useful in rapid diagnosis. PCR positivity significantly correlates with clinical evidence of disease dissemination. Bloodstream invasion is an important and common mechanism for the dissemination of the Lyme disease spirochete.

Bacteremia↗
PubMed1993

P1-antigen-containing avian egg whites as inhibitors of P adhesins among wild-type Escherichia coli strains from patients with urosepsis.

Among 58 Escherichia coli urosepsis isolates, P1-antigen-containing dove and pigeon egg whites were significantly more effective inhibitors of P-adhesin-specific agglutination than were chicken egg whites or globoside. Globoside's inefficacy may have resulted from a proadherence effect of globoside's lipid tail. Adhesin phenotypes determined with dove and pigeon egg whites as as agglutination inhibitors corresponded closely with phenotypes defined by comparative hemagglutination of human P1 and p erythrocytes. These data suggest that avian P1-antigen-containing substances may provide a useful alternative method for P adhesin inhibition among uropathogenic E. coli strains.

Adhesins, Escherichia coli↗
PubMed1986

Office diagnostic procedures.

Tympanocentesis, punch biopsy of the skin, bone marrow aspiration and biopsy, and temporal artery biopsy are procedures discussed in this article. They are principally diagnostic procedures used in the evaluation of skin and serious systemic disease.

Ambulatory Surgical Procedures↗
PubMed1985

In vitro and in vivo formation of 7-(2'-carboxyethyl)guanine from the liver carcinogen 1-nitroso-5,6-dihydrouracil and its reactions with water and methanol.

Base-catalyzed hydrolysis of the potent liver carcinogen 1-nitroso-5,6-dihydrouracil [(NDHU) CAS: 16813-36-8] afforded 3-hydroxypropionic acid and acrylic acid in 72 and 6% yield, respectively. The base-catalyzed methanolysis of NDHU gave quantitative yields of 3-methoxypropionic acid and methyl carbamate. These results indicate that base-catalyzed NDHU decomposition produces a 2-carboxyethyl carbonium-ion-type intermediate. When 3H-labeled NDHU was reacted at pH 8 with DNA and RNA, 7-(2'-carboxyethyl)guanine (CEG) was detected in the hydrolysate and was identified by its cochromatography with authentic CEG in five (for DNA) or three (for RNA) systems and by a reverse isotope-dilution procedure. Radioactively labeled CEG (identified as before) and five other labeled chromatographic fractions were present in liver DNA and RNA hydrolysates after [3H]NDHU was gavaged into MRC Wistar rats. These fractions persisted in the liver DNA for various times up to 33 days after the gavage. The CEG fraction was 94% of the radioactivity in DNA reacted in vitro, but it reached only 21% of the radioactivity in the liver DNA. The results are related to a study on single-strand breaks produced by NDHU in rat liver DNA.

Animals↗
PubMed1982

Occurrence, stability and decomposition of beta-N [gamma-L(+)-glutamyl]-4-hydroxymethylphenylhydrazine (agaritine) from the mushroom Agaricus bisporus.

A chromatographic technique was developed that could clearly separate beta-N [gamma-L(+)-glutamyl]-4-hydroxymethylphenylhydrazine (agaritine) from all other components in 10-500-microliters samples of mushroom extracts. Locally purchased mushrooms were found to contain mean levels of 0.4 - 0.7 mg agaritine g. The agaritine content of the mushrooms had decreased by 2-47% after 1 wk of storage in a domestic refrigerator and by 36-76% after 2 wk of such storage. Canned mushroom soup and canned mushrooms did not contain detectable agaritine; a sample of frozen mushrooms contained a mean level of 0.33 mg/g and a batch of fresh mushrooms lost about 32% of their agaritine content on cooking. In mice given 3 mg agaritine by gavage, agaritine was detected in all parts of the gastro-intestinal tract 15 min after dosing, but none was detectable in the gut after 3 hr. The enzyme gamma-glutamyltranspeptidase derived from pig's kidney was found to be capable of decomposing agaritine to glutamic acid and 4-(hydroxymethyl)phenylhydrazine, and to have nine times such activity as an enzyme isolated from mushrooms.

Agaricales↗
PubMed1977

Metabolism of N-nitrosohexamethyleneimine to give 1,6-hexanediol bound to rat liver nucleic acids.

Rats were gavaged with the liver carcinogen H-nitrosohexamethyleneimine labeled with 3H or 14C and killed 16 hours later. The liver RNA and DNA were isolated and hydrolyzed with 1 M HCl at 100 degrees C. Chromatography of the 3H-labelled RNA hydrolysate on a cation exchange resin (NH4+ form), with water elution, separated five radioactive peaks, with peak "E" containing 27% of the bound 3H. There were no radioactive peaks in the 7-substituted guanine region. Hydrolysis of the 3H-labeled DNA gave a similar profile, but E contained only 5% of the 3H. The major component of E was identified as 1,6-hexanediol by its behavior and/or that of its benzoate derivative on cation exchange, anion exchange, thin-layer and gas-liquid chromatography, and by recrystallization of a mixture of the E and diol benzoates to constant specific radioactivity.

Animals↗