PubMed Health⌕ Search

Biomedical subjects

A Malone

Publications and source records attributed to A Malone.

12 recordsLinked to original sources
PubMed1995

Intestinal metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in rats: Sex difference, inducibility and inhibition by phenethylisothiocyanate.

The intestinal metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) was investigated in male and female Sprague-Dawley (SD) rats and male F344 rats, using isolated perfused intestinal segments. [1(-14)C]-NNK at 1 microM was metabolized by alpha-hydroxylation, pyridine N-oxidation and carbonyl reduction. Jejunal segments from control female rats metabolized 26.2% of the NNK during transepithelial transfer to 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL, 12.2%), 4-(methylnitrosamino)-1-3-pyridyl-N-oxide)-1-butanone (NNK-N-oxide, 7.7%), 4-oxo-4-(3-pyridyl)-butanol (KAlc, 2.7%), 4-(methylnitrosamino)-1-(3-pyridyl-N-oxide)-1-butanol (NNAL-N-oxide, 1.8%), 4-oxo-4-(3-pyridyl)butyric acid (KA, 1.1%) and 4-hydroxy-4-(3-pyridyl)butyric acid (HA, 0.7%). Ileal segments metabolized 20.8% of the NNK during absorption, with no difference in metabolite distribution as compared to jejunal segments. In control male SD and F344 rats, jejunal presystemic metabolism was 2.3-fold higher (56.4% and 60.8% respectively), mainly because of a 4-fold increase in NNAL formation (44.1% and 48.5%)> total NNK metabolism was also induced in female rats by starvation (84.4% metabolites), acetone (89.3%), phenobarbital PB, 75.3%) and Clophen A50 (61%). PB and Clophen A50 induced N-oxidation to 38.9% (4 x) and 27.8% (3 x), and to a lesser extent NNAL formation and alpha-hydroxylation (2 x), Starvation mainly increased N-oxidation with a time-dependent increase from 1 day to 3 days of starvation (4 x and 8 x versus controls), whereas alpha-hydroxylation and NNAL formation was elevated only after 1 day starvation. Acetone pretreatment (3 days) stimulated all three pathways (NNAL 2 x, N-oxidation 4 x, alpha-hydroxylation 4 x). In male F344 rats, starvation and acetone induced N-oxidation (5 x and 7 x) and alpha-hydroxylation (3 x and 5 x), and decreased NNAL formation by 40%, probably due to substrate competition or further metabolism of NNAL. In acetone-induced female SD rats, NNK metabolism was inhibited by in vivo pretreatment with phenethylisothiocyanate (PEITC) or in vitro addition of 1% ethanol to the perfusate. Both inhibition experiments reduced total metabolism by 20%; N-oxidation and alpha-dhyroxylation were reduced to values found in control rats, whereas NNAL formation increased from 31% to 51%.Inhibition of NNK metabolism by PEITC im male F344 rats was less pronounced compared to female SD rats; again a decrease in alpha-hydroxylation (6.7% to 3.3%) and N-oxidation (73.6% to 35.3) was accompanied by increased NNAL formation (9.8% to 41.0%).(ABSTRACT TRUNCATED AT 400 WORDS)

Acetone↗
PubMed1987

An outbreak of ringworm in sheep in Ireland caused by Trichophyton verrucosum.

An outbreak of ringworm in sheep in Ireland caused by Trichophyton verrucosum is described. The flock consisted of 110 sheep and two separate groups within the flock were affected. Eleven of the first group of 23 sheep and five of the second group of 25 sheep showed lesions. Contact with infected cattle and fomites contaminated by the cattle are believed to have caused the outbreak. An excellent response was obtained in both infected groups by treatment with griseofulvin at a dose rate of 7.5 mg/kg daily for seven days.

Animals↗
PubMed1984

Intravenous contrast bolus in computed tomography investigation of mass lesion.

Using bolus intravenous contrast (25-75 Renografin 60) and 5-second scanning capability, better definition of vascular anatomy as well as the vascular nature of mass lesions in the chest and abdomen could be demonstrated. The immediate higher concentration of iodine in vessels and organs following initial bolus, improves visualization of these structures dramatically when compared to drip-infusion technique. A description of the technique and examples are shown.

Abdominal Neoplasms↗
PubMed1983

The KIDS Chart.

Explore the source record for details and available documents.

Age Factors↗
PubMed1983

Unicaliceal kidney associated with posterior urethral valves.

Unicaliceal kidneys are normal in several mammals, including monkeys. There have been 10 patients with this anomaly reported on in the literature and most have had additional anomalies of the urinary tract. We report on a man with a unicaliceal kidney who also had posterior urethral valves.

Adult↗
PubMed1982

Considerations in evaluating changes in outcome for infants weighing less than 1,501 grams.

Neonatal mortality for 285 infants and developmental outcome for 158 infants with birth weights of 751 to 1,500 gm, born in the Capital Regional Perinatal Center between July 1975 and December 1979, were compared with the findings in 1952, in 1965 to 1967, and in 1968 to 1970. In the 1,001- to 1,500-gm group, mortality decreased and there was an 18% incidence of major neuropsychiatric disability compared to the 48% found in 1952 when the same examination techniques and diagnostic criteria were used. More 751- to 1,000-gm infants survive now also, but 40% have a major handicap. There is a high incidence of preconceptional, prenatal, perinatal, and postnatal abnormalities in this group of very low-birth-weight infants, but the incidence is significantly higher in those with major disabilities. The infants who die and those who have subsequent major neuropsychiatric abnormalities require the sophisticated techniques of neonatal intensive care, whereas these procedures are not needed or are used only briefly for the infants who are normal. In upper New York State, the demographic shifts in race, age, parity, education, and induced abortions account for 13% of the drop in neonatal mortality in the 1,001- to 1,500-gm group. These demographic as well as social and medical care changes must be taken into account in any evaluation of the decreasing mortality and morbidity that has occurred. Improvements in prenatal, obstetric, and neonatal care appear to be doing for the 751- to 1,000-gm group now what the then high-level care in 1952 did for the 1,001- to 1,500-gm group, when mortality decreased but only half of those who survived were normal.

Congenital Abnormalities↗
PubMed1979

The validity of parental reporting of infant development.

A developmental questionnaire, encompassing the ages from 4 weeks to 36 months, has been devised that, when completed by parents, can be used to screen children as being developmentally normal, questionable, or abnormal. A total of 526 infants were screened by this questionnaire at 28 weeks of age and then examined at 40 weeks of age by a full Gesell Developmental and Neurologic Examination. Underscreening of those with major abnormalities was 2.6%, and of those with minor abnormalities, 10%. Overscreening was 6%. In view of the demonstrated high reliability and validity of the full Gesell Developmental and Neurologic Examination on which the questionnaire is based, the relatively small percentages of overscreening and underscreening make it the most accurate and useful screening questionnaire to date.

Adult↗
PubMedDate not supplied

Tobacco-specific nitrosamines--metabolism and biological monitoring of exposure to tobacco products.

Tobacco-specific nitrosamines are derived from nicotine and related tobacco alkaloids and can be detected in tobacco products as well as in mainstream and sidestream smoke. Two of them, N-nitrosonornicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, are strong carcinogens in laboratory animals. Because of its organospecificity for the lung, the latter is considered to be a causative factor in tobacco-related human lung cancer. Upon metabolic activation both nitrosamines give rise to a common reactive intermediate binding to macromolecules such as DNA and haemoglobin and hydrolysing to 4-hydroxy-1-(3-pyridyl)-1-butanone. Because of easy access to large quantities of haemoglobin from blood samples, it is most suitable for biomonitoring human exposure to tobacco-specific nitrosamines. A highly sensitive analytical method for determination of femtogram amounts of 4-hydroxy-1-(3-pyridyl)-1-butanone provides an approach to assess individual exposure to active and passive smoking.

Alkaloids↗