PubMed Health⌕ Search

Biomedical subjects

M L Casey

Publications and source records attributed to M L Casey.

At least 127 records · Page 7Linked to original sources
PubMed1982

Phospholipid and neutral lipid separation by one-dimensional thin-layer chromatography.

A simple and rapid method for separation of six major phospholipids and four major neutral lipids from cell extracts by one-dimensional preadsorbent thin-layer chromatography was developed. Due to the inert characteristics of the preadsorbent layer (Celite) no separation occurs until the sample reaches the preadsorbent (Celite)-silica gel junction. The compounds were applied to the preadsorbent (Celite) area (625 mm2) in 10-microliters aliquots (total volume of 0.15 ml). By this method, samples can be applied rapidly in large volumes without respotting any area of the preadsorbent layer. The time required to apply one sample was reduced considerably (2 min) compared to conventional methods (10 min). Since all the compounds move with the solvent front as a sharp, narrow band to the preadsorbent (Celite)-silica gel boundary, excellent separation was achieved when up to 650 micrograms of lipid material was applied on each lane (25 mm wide). Thus, this method is suitable for the separation of relatively large amounts of radiolabeled and non-radiolabeled lipids and free fatty acids from extracts of biological fluids, tissues, or cells maintained in monolayer culture.

Cells, Cultured↗
PubMed1982

Growth of the kidney in the normal human fetus during early gestation.

The weights of kidney obtained from 200 presumably normal human abortuses of postconceptional gestational ages between 6 and 17 weeks were measured. The weight of the normal human fetal kidney increases in an exponential manner between 6 and 14 weeks gestation. Thereafter, the rate of increase in weight is slower. No significant differences were found between the weights of kidneys of male and female abortuses of 7-15 weeks postconceptional gestational ages.

Female↗
PubMed1982

Growth of the adrenal gland of the normal human fetus during early gestation.

The weights of 182 adrenal glands obtained from presumably normal human fetuses delivered by elective abortion between 6 and 17 weeks post-conceptional gestational age were measured. There was little increase in adrenal weight between 6 and 12 weeks gestation. Thereafter, the rate of increase in adrenal weight was rapid. There were no significant differences between the adrenal gland of male and female abortuses of similar gestational ages.

Adrenal Glands↗
PubMed1982

Distribution of NAD+-dependent prostaglandin dehydrogenase activity among human fetal tissues.

In the present investigation the activity of NAD+-dependent 15-hydroxyprostaglandin dehydrogenase was measured in the cytosolic fractions prepared from various tissues of the human fetus. Among the different tissues studied the specific activity of this enzyme varied widely. The specific activities of prostaglandin dehydrogenase were greatest in the adrenal gland, placenta, and ureter, while moderate levels were found in kidney, lung, and testis; low or undetected levels were found in other tissues including heart, intestine, and brain. The finding of wide variations in the specific activity of prostaglandin dehydrogenase among tissues of the human fetus is supportive of the possibility that this enzyme has an important role in the regulation of the levels of prostaglandins in these tissues.

Cytosol↗
PubMed1982

Regulation of extraadrenal steroid 21-hydroxylase activity. Increased conversion of plasma progesterone to deoxycorticosterone during estrogen treatment of women pregnant with a dead fetus.

We measured deoxycorticosterone (DOC) and progesterone (P) in plasma of 47 women pregnant with a dead fetus and sequentially throughout gestation in 35 women pregnant with a live fetus. When P levels in plasma were low, the plasma levels of DOC in women pregnant with a dead fetus varied but usually were similar to those in women pregnant with a live fetus. However, when P levels were high, the levels of DOC in some women pregnant with a dead fetus were considerably lower than those in women pregnant with a live fetus. To test whether this finding was due to loss of transfer of DOC from fetus to mother or else loss of extraadrenal steroid 21-hydroxylase activity in the mother after death of the fetus, we conducted several studies. The levels of P and DOC in plasma of one woman remained constant from 30 min after fetal death until delivery occurred 13 h later. Estrogen treatment of four women pregnant with a dead fetus brought about an increase in plasma levels of DOC in three of the women. In one woman the ratio of plasma DOC to P was 0.015, a value similar to that found before fetal death, but was 0.003 after fetal death but before estrogen treatment. In two women pregnant with a dead fetus the transfer constants of conversion of plasma P to DOC were 0.011 and 0.005 before, and 0.024 and 0.013, respectively, during estrogen treatment. In one woman pregnant with a deformed fetus with adrenal agenesis, the metabolic clearance rates of DOC before and during estrogen treatment were similar, whereas the plasma production rates of DOC were 2.75 before and 4.31 mg/24 h during estrogen treatment. We suggest that (a) the DOC in plasma of near-term pregnant women arises in part by extraadrenal 21-hydroxylation of plasma P and (b) estrogen stimulates steroid 21-hydroxylase activity in extraadrenal tissues.

Adrenal Glands↗
PubMed1982

Metabolism of deoxycorticosterone and deoxycorticosterone sulfate in men and women.

In this investigation we found that little of intravenously infused [14C]deoxycorticosterone (DOC) was converted to [14C]DOC-SO4 that entered plasma. Moreover little of intravenously infused [3H]DOC-SO4 was metabolized by way of DOC except by intestinal bacterial enzymes. However evidence was obtained that plasma DOC is converted to DOC-SO4 in liver, but little of the DOC-SO4 formed in liver escapes into blood; rather the DOC-SO4 enters bile and in the intestine is converted, in part, to progesterone (or metabolites thereof) by the action of bacterial enzymes. The estimated intrahepatic fractional conversion of DOC to DOC-SO4 was significantly greater in premenopausal women (0.72 +/- 0.118, mean +/- SEM) than in men (0.28 +/- 0.036, P less than 0.005).

Adult↗
PubMed1982

Mesenchyme-epithelial interactions in human endometrium. Prostaglandin synthesis in separated cell types.

Glandular epithelium and stromal cells of human endometrium were separated and maintained in monolayer culture. At the time the cells became confluent, cell suspensions were prepared and incubated with [14C]arachidonic acid. Radiolabeled prostaglandin E2 and, to a lesser extent, prostaglandin F2 alpha and metabolites of these prostaglandins, were formed principally in stromal cells. There was considerably less prostaglandin formation in endometrial glands either after maintenance in monolayer culture or in freshly separated glands. In stromal cells of endometrium prostaglandin formation was linear with time of incubation for 2.5 min and with [14C]arachidonic acid concentrations up to 8 microM. When stromal cells and epithelial cells were combined, all prostaglandin formation could be accounted for by that produced in stromal cells. Little or no prostaglandin formation was detected in stromal cells from human adipose tissue or in fibroblasts from human genital or abdominal skin or human fallopian tube.

Arachidonic Acid↗
PubMed1982

Formation of deoxycorticosterone from progesterone in extraadrenal tissues: demonstration of steroid 21-hydroxylase activity in human aorta.

In the present investigation, we demonstrated the presence of steroid 21-hydroxylase activity in microsome-enriched fractions prepared from homogenates of aortal tissues of human abortuses and a prepubertal boy. The specific activities of this enzyme in microsomes prepared from aortal tissue of various abortuses varied but was similar to that found previously in microsomes prepared from human fetal kidney tissue. However, the specific activity of steroid 21-hydroxylase in microsomes prepared from smooth muscle tissue of the aorta of a prepubertal boy was extraordinarily high, viz., 705 pmol x h-1 x mg-1 protein. Thus the potential exists for the formation of deoxycorticosterone (DOC) in aorta, another tissue site of DOC action.

Aorta↗
PubMed1982

NAD+-dependent 15-hydroxyprostaglandin dehydrogenase activity in kidney tissue from NZB/NZW F1 hybrid mice.

Prostaglandins, or related compounds, as well as estrogen and androgen are believed to be involved in the processes that lead to the development of murine lupus erythematosus (LE) in NZB/NZW F1 hybrid mice. In this investigation we measured NAD+-dependent 15-hydroxyprostaglandin dehydrogenase (PGDH) activity in kidney tissue of male and female NZB/NZW F1 hybrid mice and in kidney tissue of male and female mice of other strains. In each case the specific activity of PGDH was significantly greater in kidney tissue of male than in kidney tissue of female mice. However, the specific activities of PGDH in kidney tissues of males of various strains of mice were similar, and the specific activities of PGDH in kidney tissues of females of various strains-including the NZB/NZW F1 hybrid- were similar. Thus, while the lower activity of PGDH in kidney tissues of the female may be important in the pathogenesis of LE, the lower activity of this enzyme is not unique to the kidney of the female NZB/NZW F1 hybrid mouse.

Animals↗
PubMed1981

Initiation of human parturition. XII. Biosynthesis and metabolism of prostaglandins in human fetal membranes and uterine decidua.

Prostaglandin synthetase activity was assayed in homogenates prepared from human fetal membranes and uterine decidua tissues with [14C] arachidonic acid used as substrate. In amnion, chorion laeve, and decidua vera tissues obtained after the spontaneous onset of labor and vaginal delivery the mean specific activities of prostaglandin synthetase were respectively 1.47, 0.53, and 0.39 nmoles x hr-1 x gm-1 tissue; in these same tissues obtained at elective cesarean section before the onset of labor the mean specific activities of prostaglandin synthetase were respectively 0.61, 0.33, and 0.28. The specific activity of prostaglandin synthetase of amnion (but not chorion laeve or decidua vera) was significantly greater in samples obtained after labor than in those obtained before labor (p less than 0.02). Prostaglandin synthesis in amnion, chorion laeve, and decidua vera was inhibited by acetylsalicylic acid and by indomethacin. Prostaglandin E2 was formed in amnion and chorion laeve, whereas prostaglandin E2 and prostaglandin F2 alpha were formed in decidua vera. The activity of NAD+ -dependent 15-hydroxyprostaglandin dehydrogenase was also assayed and the specific activities of this enzyme in chorion laeve and decidua vera tissues obtained before and after labor were high, whereas 15-hydroxyprostaglandin dehydrogenase activity in amnion was low.

Amnion↗
PubMed1981

Deoxycorticosterone biosynthesis from progesterone in kidney tissue of the human fetus.

The levels of deoxycorticosterone (DOC) and DOC sulfate are extraordinarily high in the umbilical cord plasma of human newborns. However, the sources of DOC and DOC sulfate in the human fetus are not defined. Recently, it was shown that plasma progesterone was converted to DOC in extraadrenal tissues in pregnant, nonpregnant, and adrenalectomized women and in men. Thus, DOC formation from plasma progesterone constitutes another example of the formation of a biologically active steroid hormone from a circulating precursor. In addition, the conversion of [3H]progesterone to [3H]DOC in homogenates and microsome-enriched preparations of adult human kidney tissue was demonstrated. To investigate the origin of DOC in the human fetus, we sought 1) to ascertain whether steroid 21-hydroxylase activity was present in human fetal kidney tissue and 2) to establish the kinetics of the reaction catalyzed by this enzyme should it be present in fetal kidney. We employed microsome-enriched preparations of kidney tissue obtained from human abortuses of 9-20 weeks gestation. [3H]DOC formation from [3H]progesterone (1 microM) proceeded in a linear fashion for 3 h. and the rate of formation of [3H]DOC from [3H]progesterone (1 microM) was linear with a microsomal protein concentration between 0.026-0.512 mg X ml-1. The value computed for the apparent Km of steroid 21-hydroxylase in fetal kidney for progesterone was 0.146 microM. We conclude that the human fetal kidney may be an important site of DOC formation as well as a site of DOC action.

Desoxycorticosterone↗
PubMed1981

Deoxycorticosterone sulfate biosynthesis in human fetal kidney.

The levels of deoxycorticosterone (DOC) and DOC-SO4 are extraordinarily high in umbilical cord plasma of human newborns compared to those in plasma of men and nonpregnant women. Progesterone is converted to DOC in minces, homogenates, and microsome-enriched preparations of human fetal kidney tissue. Since DOC, a mineralocorticosteroid, is formed in situ in kidney, its potential site of action, we sought to define whether sulfurylation of DOC also occurred in fetal kidney. We found that radiolabeled DOC-SO4 was formed from [3H]DOC and from [3H]progesterone in minces of human fetal kidneys. C-21 hydroxysteroid sulfotransferase activity was found to be localized principally in the cytosolic fraction of homogenates of human fetal kidney tissue and was present in both the cortical and medullary portions of fetal kidney. In cytosolic fractions prepared from homogenates of human fetal kidneys, we found that the apparent Km of the C-21 hydroxysteroid sulfotransferase for DOC was 4.7 microM; the reaction was linear with time for 60 min and was linear with protein concentration up to 1.2 mg X ml-1 incubation mixture. Thus, DOC-SO4, as well as DOC, is synthesized in the kidney of the human fetus, and kidney may be an important site of formation of these steroids that are found in fetal blood in very high concentrations.

Cytosol↗
PubMed1981

Sex and age differences in the specific activity of NAD+-dependent 15-hydroxyprostaglandin dehydrogenase in human fetal kidney tissue.

The specific activity of NAD+-dependent 15-hydroxyprostaglandin dehydrogenase (PGDH) was significantly greater (P less than 0.005) in human kidney tissue obtained from male abortuses aged 10--16 weeks after conception than in female abortuses of the same gestational age and in younger male and female abortuses. There was a significant correlation (r = 0.93, P less than 0.001) between the specific activity of PGDH in fetal kidney and testicular tissues obtained from human abortuses of 10--26 weeks gestational age. These results suggest a role for testosterone in the regulation of PGDH activity in the fetal kidney.

Female↗
PubMed1981

Nicotinamide adenine dinucleotide-dependent 15-hydroxyprostaglandin dehydrogenase activity in hydatidiform mole tissue and choriocarcinoma cells.

Prostaglandins may occupy an important role in viral and chemical carcinogen-induced neoplasia. To evaluate the possible role of prostaglandin catabolism in neoplastic cells, we measured nicotinamide adenine dinucleotide-dependent 15-hydroxyprostaglandin dehydrogenase activity in hydatidiform mole tissue and in choriocarcinoma cells maintained in monolayer culture. The specific activity of nicotinamide adenine dinucleotide-dependent 15-hydroxyprostaglandin dehydrogenase in hydatidiform mole tissue (0 to 1.2 nmol 15-ketoprostaglandin E2 formed x min-1 x mg-1 cytosolic protein) and in choriocarcinoma cells (1.0 nmol 15-ketoprostaglandin E2 x min-1 x mg-1 protein) was strikingly less than that found in normal placental tissue [11.4 +/- 2.3 (S.E.) nmol 15-ketoprostaglandin x min-1 x mg-1 protein].

Cells, Cultured↗
PubMed1980

NAD+-dependent 15-hydroxyprostaglandin dehydrogenase activity in human endometrium.

The specific activity of NAD+-dependent 15-hydroxyprostaglandin dehydrogenase was measured in human endometrial tissue obtained from ovulatory and anovulatory women. Employing PGE2 as substrate, the specific activity of this enzyme was found to be highest in endometrial tissue during the secretory phase of the cycle (ovarian cycle days 15-25) and lowest in menstrual (days 1-5) and premenstrual (days 26-28) endometrium. The specific activity of prostaglandin dehydrogenase in endometrium of anovulatory women was low, being similar to that found in proliferative endometrium (days 6-14) of ovulatory women. Prostaglandin dehydrogenase activity was found in the cytosolic fraction prepared from endometrial ti-sue, and was found principally in the glandular epithelium following separation of endometrial glands and stromal cells.

Cytosol↗