PubMed Health⌕ Search

Biomedical subjects

J A Butler

Publications and source records attributed to J A Butler.

At least 37 records · Page 2Linked to original sources
PubMed1999

Glutathione peroxidase activity modulates fatty acid profiles of plasma and breast milk in Chinese women.

Since little is known about the effect of selenium on the fatty acid profiles (FAP) of human breast milk, the purpose of this study was to measure the effect of habitual dietary selenium (Se) intake on this profile in plasma and breast milk. Subjects were lactating women from three locations in China where habitual selenium intakes are extremely low (Xichang), adequate (Beijing), or extremely high (Enshi). Plasma and milk samples were obtained within seven days of parturition (early samples) or within eighteen months postpartum (mature samples) and analyzed for selenium concentration, glutathione peroxidase (Gpx) activity and FAP. Plasma and milk selenium concentrations were significantly lower in the samples from women from Xichang and significantly higher in those from Enshi when compared to those from Beijing. Plasma Gpx activity, however, was higher in samples from Beijing than Xichang or Enshi. In contrast, the early breast milk samples had similar Gpx activity regardless of location. The mature samples, however, followed the same trend as plasma with the samples obtained from the women in Beijing having the highest activity. Of the unsaturated fatty acids examined, the concentration of linoleic acid, 18:2(n-6), in both plasma and milk was greater in the samples from Beijing when compared to those from Xichang or Enshi. Thus dietary selenium appears to influence the fatty acid composition in human breast milk, but influences Gpx activity only in mature milk samples.

Adult↗
PubMed1999

Effect of dietary selenium restriction on selected parameters of selenium status in men with high life-long intake.

The influence of selenium (Se) restriction on disposition in plasma and urine fractions of infused (74)Se (selenite) was studied when adult males (Enshi City, Hubei Province, PRC) whose habitual daily Se intake is approximately 480 microg per day were transferred to Lichuan County, where the daily intake is approximately 30 microg. The subjects received an infusion (106 microg Se) on the day before consuming foods low in Se and a second infusion (113 microg Se) 63 days later. Blood and 24-hour urine samples were collected each day for 7 days after the first infusion and on days 22, 43, and 62 following the first infusion. Urine and blood were also collected daily for the next 7 days after the second infusion. Plasma total Se concentration increased for 7 days after each of the two infusions and urine Se decreased exponentially following both the first and second infusions. The excretion of trimethylselenonium followed the same pattern as the total urinary Se. Surprisingly, there was not a significant difference in selenite retention between the two infusion periods, and the data indicated that, regardless of the chemical form of Se present in various organs, its catabolism leading to excretion in urine followed the same pathway as that of selenite. Labeled Se was incorporated predominantly in the plasma selenoprotein P fraction and the half-life of Se in this fraction was determined to be 1.9 to 2.9 days. Thus, a longer depletion period is required in these subjects to obtain more significant changes.

Journal Article↗
PubMed1999

Evidence for extensive distribution of oestrogen receptor alpha-immunoreactivity in the cerebral cortex of adult rats.

The presence of oestrogen receptor alpha (ERalpha)-immunoreactivity (IR) in the cerebral cortex of adult rats has been investigated. Previous studies have reported a negligible presence of ERalpha or ERalpha mRNA in this region of the adult rat brain. We have used immunoprecipitation and immunohistochemistry, with various antibodies and fixatives, to detect this protein in the cingulate cortex. When the tissue was fixed using paraformaldehyde alone only faint ERalpha-IR was observed at this site. In contrast, following fixation either with acrolein (with or without paraformaldehyde) or with a mixture of paraformaldehyde and glutaraldehyde there was extensive ERalpha-IR throughout layers II to VI; this was absent when the antibodies were preincubated with the peptide fragment used in their production. The presence of ERalpha-IR in the nonfixed cingulate cortex of adult rats was confirmed by immunoprecipitation.

Acrolein↗
PubMed1999

Evidence for oestrogen receptor alpha-immunoreactivity in gonadotrophin-releasing hormone-expressing neurones.

Having used the cingulate cortex to demonstrate the validity of our methods for detecting hitherto unrecognized oestrogen receptor alpha (ERalpha)-immunoreactive neurones, we have now employed immunoprecipitation and double-label immunohistochemistry to investigate whether the ERalpha protein is present in gonadotrophin-releasing hormone (GnRH)-containing cells. The immortalized GnRH cell line GT1-7 and GnRH neurones within the rat preoptic area were found to possess ERalpha-immunoreactivity (ERalpha-IR). These observations indicate that oestrogen may regulate the synthesis and release of GnRH by direct actions on GnRH neurones.

Acrolein↗
PubMed1999

Metabolism of selenite in men with widely varying selenium status.

OBJECTIVE: This study was undertaken to investigate the metabolism of selenite in men with life-long intakes of deficient, adequate and excess selenium. METHODS: Stable isotopes of selenium were infused for five hours into Chinese men living in deficient, adequate or excessive selenium areas, and 24-hour urine and blood samples were collected daily for the next seven days. Stable isotopic selenium excretion was determined in urine and in whole plasma and plasma fractions. RESULTS: Even though there was a positive correlation of selenium intake with the urinary excretion of this element, this relationship was not linear over the entire range (deficient, adequate, excessive) of selenium intake. When the urine excretion was normalized internally within each group, a sharp increase in the slope of this relationship was found when long-term intake increased to adequate amounts, but the slope reached a plateau when the daily intake exceeded the adequate group. The plasma selenoprotein P fraction was labeled initially, but the incorporation in the glutathione peroxidase fraction subsequently increased by a small amount. A two-month dietary restriction of selenium of the subjects from the excess area did not result in a reduction of urinary excretion of infused selenite. CONCLUSION: A complex relationship exists between long-term intake of selenium and selenium status, and subjects living in the excess area are more saturated with selenium than anticipated. More than two months of depletion are required to affect urinary excretion of selenium.

Adult↗
PubMed1999

Signet ring cell histology is associated with unique clinical features but does not affect gastric cancer survival.

Signet ring cell histology is found in 3 to 39 per cent of gastric cancer cases and has been reported to be a feature of poor prognosis, although this issue has not been rigorously examined. The objective of this study was to determine those demographic and clinical variables associated with signet ring cell histology and to determine the effect of signet ring cell histology on survival using multivariate analyses. We studied a historical cohort of consecutive cases of gastric cancer reported to the population-based California Cancer Registries of Orange, San Diego, and Imperial Counties from 1984 through 1994. Factors associated with signet ring cell histology were assessed using chi2 and logistic regression. Life tables were constructed to assess unadjusted survival and survival differences in patient subgroups. Multivariate survival was determined using a Cox proportional hazards model. Of 3020 patients, 464 (15%) had signet ring cell histology. Patients with signet ring cell histology were more likely to be younger than 50 years (odds ratio (OR) = 2.4; 95% confidence interval (CI) = 1.6-3.5), less likely to be male (OR = 0.49; 95% CI = 0.37-0.66), and more likely to have tumors of the distal stomach (OR = 2.0; 95% CI = 1.4-3.0). Signet ring cell histology did not adversely affect unadjusted overall survival, race-stratified survival, or stage-stratified survival. Multivariate analysis indicated that patients with signet ring cell histology had an insignificant increased risk of dying (relative risk = 1.027; P>0.10) in comparison with patients without signet ring cell histology. Patients with signet ring cell histology were more likely to be young women and to have tumors of the distal stomach. Signet ring cell histology did not impact survival in our group of largely advanced gastric cancer cases.

Adult↗
PubMed1999

Quantitative significance of measuring trimethylselenonium in urine for assessing chronically high intakes of selenium in human subjects.

The purpose of the present study was to investigate the effects of Se restriction on the excretion of Se in men who had consumed high levels of this element during their entire lives. With the use of stable isotopes of Se as selenite, the excretion of methylated Se in urine was investigated in Chinese men (n 10) who had habitual chronic high intakes of this element. The relationship between either urine Se or trimethylselenonium (TMSe) to the estimated long-term Se intake was not linear over the entire range of intake, which was also true for the infusion of labelled selenite. A non-linear relationship was also found between urine TMSe and urine Se both for TMSe arising from catabolism of endogenous body Se and that from infused selenite. The data suggest a close precursor-product relationship of urine Se and its TMSe component based on the nearly identical specific activities for these two selenocompounds. Although dimethylselenide in breath was not measured in the present study, combining urinary TMSe with this breath test may be more useful in the assessment of long-term Se status.

Adult↗
PubMed1998

An evidence-based approach to the treatment of esophageal variceal bleeding.

Esophageal varices are a life threatening cause of gastrointestinal bleeding. Management includes both primary prevention of variceal bleeding and treatment of actively bleeding varices. Evidence from randomized controlled trials indicates that beta blockers and nitrates may prevent the initial episode of bleeding varices. Ample data from randomized controlled trials indicate that band ligation is more effective than scleropathy for the treatment of bleeding esophageal varices. Somatostatin may decrease rebleeding rates with or without endoscopic therapy. No effective treatment has been developed for the treatment of patients who fail endoscopic therapy.

Adult↗
PubMed1998

Distribution of selenium between plasma fractions in guinea pigs and humans with various intakes of dietary selenium.

The distribution of selenium between the plasma fractions was investigated in guinea pigs fed various levels (basal, 0.5, 1.0, 2.0, 4.0, 6.0 and 8.0 mg Se/kg) of dietary selenomethionine (Semet) and in humans living in different areas of China with different selenium status. There was a corresponding increase of selenium concentration in liver, kidney, brain, testis, spleen, heart and muscle with each increase of dietary selenium, but there were no increases of glutathione peroxidase (GPX) activity in liver, brain, testis, heart or muscle in pigs fed any of the selenium levels as compared to controls fed a basal commercial diet. On a percentage distribution basis, the selenium in selenoprotein P decreased and that in the albumin fraction increased with increased dietary intakes of selenium as Semet. The ratios of selenium to albumin in either the plasma or the albumin fractions increased with each increase in dietary selenium. The greatest percentage of selenium was in the albumin fraction of Chinese living in the high selenium areas whereas the greatest amount was in the selenoprotein P fraction in subjects living in deficient and adequate areas of China. Increases in the ratios of selenium to albumin in either the plasma or the albumin fraction also occurred with increases of selenium intake of these subjects. The results indicate that the distribution of selenium in plasma fractions reflect the levels of dietary intakes of Semet.

Adult↗
PubMed1998

Organic and inorganic selenium supplementation to lactating mothers increase the blood and milk Se concentrations and Se intake by breast-fed infants.

The aim of this study was to determine the effect of selenium (Se) supplementation to lactating women on Se concentrations and glutathione peroxidase (GSH-Px) activities in blood components of mothers and breast-fed infants and on milk Se levels and Se intake by breast-fed infants. Lactating mothers were supplied for 3 months with 200 micrograms Se/day in the form of yeast-Se (Y-Se) and sodium selenite. Initial blood and plasma Se levels of all women (n = 67) were 76.6 and 53.2 micrograms/L, respectively. After 3 months Se concentrations both in whole blood and in plasma from mothers and infants were significantly higher than the initial values. Y-Se exerts a stronger effects than selenite on blood and plasma Se levels. Initial milk Se concentration was 8.9 micrograms/L and after 1 month in both groups in reached a plateau at 14-16 micrograms/L. This resulted in an increase of Se intake in breast-fed infants from 6.1 to a plateau of 11-13 micrograms Se/day. GSH-Px activities in plasma and red cells of Y-Se group increased significantly and reached a plateau after 1 and 2 months, respectively, while in the selenite group the enzyme activities increased steadily throughout the entire period of the study. Selenite exerts a stronger effect on GSH-Px both in maternal and in infant blood components as compared with Y-Se. In milk the GSH-Px activity in the Y-Se group did not change during the study, while in the selenite group after 3 months it increased almost 2-fold compared to the initial value. In conclusion, this study shows that organic Se causes higher Se deposition than did the inorganic form.

Adult↗
PubMed1997

Dietary selenium increases selenoprotein W levels in rat tissues.

Two experiments were conducted to evaluate the influence of dietary selenium (Se) on tissue levels of selenoprotein W (Se-W) in rats. Se dependent glutathione peroxidase (GPX) activity and Se levels were also determined for comparative measurements. In the first experiment, rats were fed a basal diet deficient in Se or supplemented with either 0.1 or 4.0 mg Se (as selenite) per kg diet for 6 wk. Se-W levels were significantly higher in muscle, spleen and testes of rats fed 0.1 mg Se per kg diet compared to those fed the deficient diet (controls), and those fed 4.0 mg Se per kg diet had significantly higher levels in muscle, brain and spleen (P < 0. 05) than those fed 0.1 mg Se per kg diet. No further increases, however, occurred in the tests. There was a significant increase (P < 0.05) of mRNA encoding Se-W in muscle with each increase of dietary Se. In the second experiment rats were fed the basal diet or this diet plus 0.01, 0.03, 0.06, 0.1, 1.0, 2.0 or 4.0 mg Se per kg diet. The levels of Se-W in muscle did not increase (P < 0.05) until 0.06 mg Se per kg diet were fed to rats. A very marked increase (P < 0.05) occurred when 1.0 mg Se per kg diet was fed with no further increases with higher levels. There was a linear increase of Se-W in brain (r = 0.89) and spleen (r = 0.98) with the Se concentration in the diet up to 0.1 mg Se per kg where a plateau was reached. The testes showed a different pattern in that a very marked increase (P < 0.01) occurred when only 0.01 mg Se per kg diet was fed where an inflection was reached. Except for muscle, GPX activities reached a plateau in all tissues when diets containing 0.06 to 0.1 mg supplemental Se per kg were fed. The Se concentration in these tissues increased at a linear rate with the Se concentration in the diets up to 0.1 mg Se per kg where it continued to rise at a different rate. The results indicate that in rats, the regulation of Se-W by Se is different for various tissues and differs from that for GPX.

Administration, Oral↗
PubMed1997

Hormone replacement therapy and the risk of breast lesions that predispose to cancer.

To determine whether postmenopausal individuals being treated with hormone replacement therapy (HRT) have an increased risk for lesions that predispose to breast cancer, 156 women with benign breast lesions were retrospectively studied. Their ages ranged from 43 to 88. Each patient underwent a breast biopsy from 1991 to 1995. It was determined from chart review whether each of these patients had been treated with HRT. Fifty-seven of these patients had a biopsy finding that predisposed the patient to future breast cancer. The predisposing lesions included sclerosing adenosis, intraductal papilloma, and epithelial hyperplasia with atypia. Of these 57 patients, 36 (63%) were being treated with HRT. Only 30 of the 99 patients (30%) with nonproliferative lesions were treated with HRT (odds ratio, 3.9; P < 0.0005). On the basis of the results of this study, we believe that the use of HRT may promote lesions that predispose to cancer. This suggests that patients treated with HRT require vigilant surveillance by way of examination and mammography.

Adult↗
PubMed1994

Uptake of selenite, selenomethionine and selenate by brush border membrane vesicles isolated from rat small intestine.

The uptake of selenite, selenate and selenomethionine (SeMet) was performed with brush border membrane vesicles (BBMV) prepared from rats fed selenium-deficient and supplemented diets. At equilibrium (60 min), the uptake of 75Se from [75Se]selenite ranged from 16.5 to 18.9 nmol mg-1 protein. There was a curvilinear relationship in the uptake of selenite over a concentration range of 10-1000 microM. About 2 nmol mg-1 protein was obtained with selenomethionine (SeMet) which occurred between 90 and 180 s. In contrast to selenite, there was a linear relationship in the initial uptake of SeMet over a concentration range of 10-1000 microM. The uptake of selenate was approximately 50-fold lower than selenite, reaching 350 pmol mg-1 protein. Dietary selenium level had no effect on the rate of 75Se accumulation by BBMV. Dramatic differences are found in the uptake and binding of selenium by BBMV incubated with different selenocompounds.

Animals↗
PubMed1994

Goblet cell carcinoid of the appendix.

BACKGROUND: Over the past 15 years, a variant of appendiceal carcinoid has been recognized which is not widely known to the general surgeon. This tumor, variously labeled adenocarcinoid or goblet cell carcinoid, has a more aggressive natural history than classic appendiceal carcinoids and requires a different surgical approach. PATIENTS AND METHODS: A survey of the tumor registries of 10 hospitals identified 7 female and 2 male patients with goblet cell carcinoid of the appendix between 1983 and 1993. The clinical data of these patients were reviewed. RESULTS: Median age was 58 years (range 31 to 73). Clinical presentation followed two distinct patterns: acute onset suggestive of appendicitis or chronic symptoms associated with a pelvic mass. In no case was the diagnosis suspected preoperatively or established intraoperatively. Four patients with discrete distal appendiceal tumors treated with appendectomy are alive without evidence of disease 2 to 11 years since their diagnoses. The 5 patients with diffuse appendiceal involvement all had intra-abdominal metastases. Four are dead of disease at intervals from 5 months to 2 years postdiagnosis. CONCLUSIONS: Goblet cell carcinoids are a distinct clinical and pathologic entity with variable malignant potential. Patients with diffuse appendiceal involvement require aggressive surgery as part of multimodal therapy.

Adult↗