Biomedical subjects

M C Robertson

Publications and source records attributed to M C Robertson.

At least 55 records · Page 3Linked to original sources

PubMed1994

Cholesteryl ester transfer in patients with renal failure or renal transplants.

Plasma newly-synthesized cholesteryl ester transfer (NCET) rate and concentrations of lipids, lipoproteins and apolipoproteins A1 and B were measured in chronic renal failure patients (dialysis independent and dialysis dependent), patients with a functioning renal transplant and in healthy control subjects with comparable ages and plasma triglycerides. Plasma NCET rates and apoB concentrations were significantly higher in patients treated by continuous ambulatory peritoneal dialysis (CAPD) compared with controls. In normolipidemic subjects (cholesterol < 6.5 mmol/liter, triglycerides < 2.0 mmol/liter), plasma NCET rates did not differ significantly from rates in the corresponding control subjects. In hyperlipidemic subjects, plasma NCET rates were significantly higher than rates in the normolipidemic subgroup. Plasma NCET rates were correlated closely with plasma apoB levels in all renal patients combined (r = 0.754, N = 53, P < 0.001) and with plasma cholesteryl ester mass transfer (r = 0.853, N = 13, P < 0.001). We conclude that, in the absence of hyperlipidemia, plasma NCET rate is normal in patients with chronic renal failure irrespective of the treatment for uremia, and when hyperlipidemia is present NCET rates are raised and may contribute to elevated levels of the proatherogenic apoB-containing lipoproteins.

Adolescent↗

PubMed1994

Is low blood pressure in elderly people just a consequence of heart disease and frailty?

Low blood pressure has been associated with increased mortality in older people, but it is unclear whether the hypotension is a risk in its own right or just a marker of disease. In this study we investigated the extent to which those in the lowest decile of systolic and diastolic pressures could be predicted by measures of cardiovascular disease and frailty. We studied 782 people 70 years and over drawn from the only group of general practices in a rural township. Hypotension was defined separately for systolic and diastolic blood pressures as a pressure less than the tenth percentile for the sample as a whole. This was a systolic pressure of < or = 122 mmHg and a diastolic pressure of < or = 68 mmHg. There was a significant relationship between low systolic blood pressure and male sex, history of myocardial infarction by questionnaire and low body mass index (BMI), and between low diastolic pressure and male sex, history of angina and myocardial infarction, use of one or more hypotensive drugs, low BMI, low corrected arm muscle area, low self-maintenance score and the use of two or more home services. There was no association with ECG abnormalities. In the multivariate analysis only 4.2% of those with low diastolic pressure and none of those with low systolic pressure could be correctly classified. Hypotension in old age is only partially explained by established cardiovascular disease and frailty.

Activities of Daily Living↗

PubMed1994

Expression, purification, and characterization of recombinant rat placental lactogen-I: a comparison with the native hormone.

Rat placental lactogen-I (rPL-I), a member of the PRL/GH gene family, is produced by giant cells in the early trophoblast. The small amount of early placental tissue has limited the purification of rPL-I from this source. To obtain sufficient material for in vitro studies we have used a rPL-I cDNA to express this protein in Chinese hamster ovary (CHO) cells and in these studies have compared the recombinant protein with the native rPL-I. Using an affinity column composed of monoclonal antibody to rPL-I coupled to Sepharose 4B, we have purified rPL-I from four sources: 1) recombinant rPL-I produced and secreted in rPL-I-transfected CHO cells, 2) nonglycosylated recombinant PL-I produced by adding tunicamycin (10 microM/ml medium) to rPL-I-transfected CHO cells, 3) native rPL-I secreted by rat choriocarcinoma (RCHO) cells, and 4) serum rPL-I isolated from day 12 pregnant rats. Analysis by two-dimensional polyacrylamide gel electrophoresis and Western blotting revealed nine subforms with increasing mol wt [approximately 34 kilodaltons (kDa)] and acidic pI for recombinant rPL-I and RCHO-derived rPL-I. Four major species of lower mol wt (approximately 23 kDa) were evident in the nonglycosylated rPL-I, suggesting additional peptide cleavage sites. Serum rPL-I contained four additional forms of higher mol wt (approximately 37 kDa) and more acidic pI. When analyzed by the Nb2 lymphoma cell bioassay, RCHO rPL-I, serum rPL-I, and nonglycosylated rPL-I were equipotent with ovine and human PRL. Recombinant rPL-I was 1.5-2.0 times as active as ovine PRL in the Nb2 assay. A RIA was established for rPL-I. The variant rPL-Iv, displayed nonparallel displacement of [125I]rPL-I from the antibody. There was no cross-reactivity with other pituitary or placental members of the GH/PRL family. Measurement of serum levels of rPL-I by RIA after the injection of recombinant-rPL-I into adult female Sprague-Dawley rats revealed a half-life of 9 min for the recombinant protein compared to 7.8 min for the choriocarcinoma-derived hormone. In conclusion, we have shown that although CHO cells will glycosylate the recombinant protein differently than normal placental cells, the biological properties of our recombinant rPL-I are similar to those of the native, placenta cell-derived hormone.

Animals↗

PubMed1993

Relation of age, exercise, anthropometric measurements, and diet with glucose and insulin levels in a population aged 70 years and over.

A community-based sample of people > or = 70 years from Mosgiel, New Zealand, was investigated to determine the relation of age, diet, exercise, drugs, and anthropometric measurements with glucose and insulin. From an initial sample of 856 subjects on August 1, 1988, 782 (91.4%) completed the questionnaires and physical examination. Glucose was estimated in 726 subjects and insulin in 607 subjects 2 hours after a standardized meal. In the multivariate analysis for women, glucose was related to age and exercise, and insulin was related to glucose levels, triceps skinfold thickness, and waist/hip ratios. In the multivariate analysis for men, none of the variables was related to glucose levels; insulin levels were related to glucose and waist/hip ratio. Impaired glucose tolerance in women was associated with high body mass index, waist/hip ratio, lower exercise levels, and the taking of thiazide drugs or oral steroids. In men, no significant model to identify those with impaired glucose tolerance could be developed. Glucose and insulin levels in women were related to age and external factors, particularly exercise and anthropometric measurements. In men, external factors were less clearly related to glucose and insulin levels, but this lack of association in men may be due to the smaller number of men in the sample, their younger age, and the narrower range of values found in the men.

Age Factors↗

PubMed1993

A factor(s) from a rat trophoblast cell line inhibits prolactin secretion in vitro and in vivo.

The purpose of the present study was to measure the inhibitory action of secretions from trophoblast cells on prolactin (PRL) secretion in cycling and pregnant rats, and to determine whether factor(s) from trophoblast cells act directly on anterior pituitary cells. A rat choriocarcinoma cell line (Rcho)--a line consisting of trophoblast cells, including differentiated giant cells that secrete members of the placental PRL family--was used. When Rcho cells (1 x 10(6) cells) were transplanted under the kidney capsule of cycling rats, tumors developed and the rats went into constant diestrus. Eight days after cell injection, plasma progesterone was significantly increased in treated rats compared to controls, whereas plasma and pituitary PRL and pituitary PRL mRNA levels were significantly decreased. Similar PRL results were seen on Day 9 of pregnancy after injection of Rcho cells on Day 0 or Day 1 of pregnancy. To determine whether secretions from Rcho cells had a direct effect on anterior pituitary cells to inhibit PRL release, anterior pituitary cells were enzymatically dispersed and cultured for 4 days. Conditioned medium was obtained from 9-day Rcho cell cultures and concentrated by ultrafiltration. A fraction containing substances with molecular weights greater than 10,000 suppressed PRL release from the pituitary culture after 3 and 24 h. Conditioned medium containing substances with molecular weights between 1000 and 10,000 had no effect on PRL release, nor did conditioned medium from a placental cell line designated HRP-1. HRP-1 also contains trophoblast cells but does not contain the differentiated giant cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1993

Plasma cholesterol ester transfer protein and distribution of cell cholesterol among plasma lipoproteins in vitro in distance runners and sedentary men.

Plasma cholesteryl ester transfer protein (CETP) activity and distribution of red blood cell (RBC) cholesterol among plasma lipoproteins during incubation of blood were determined in 14 distance runners and 10 sedentary men. Mean plasma CETP activity was similar in the runners (31% 10 microliters-1 18 h-1) and the sedentary men (32% 10 microliters-1 18 h-1). There was significantly (P < 0.05) greater accumulation of cell cholesterol in the HDL fraction (runners: 0.33 mmol l-1; sedentary men: 0.23 mmol l-1) which comprised a significantly (P < 0.05) larger proportion of the total amount of cell cholesterol lost to plasma (runners: 89%; sedentary men: 64%) in incubated blood from the runners. The results of this study suggest that in distance runners, high HDL concentrations are not accompanied by reduced plasma CETP levels but in conjunction with low triglyceride-rich lipoprotein levels in plasma, may promote preferential distribution of cell cholesterol into the 'antiatherogenic' HDL fraction.

Adult↗

PubMed1993

Over 80 years and no evidence of coronary heart disease: characteristics of a survivor group.

OBJECTIVE: To determine factors that characterize those 80 years and over free of clinical coronary heart disease (CHD). DESIGN: Cross-sectional intergroup comparison. SETTING: Rural New Zealand town. SUBJECTS: All those 70 years and over registered with the sole health center. Seven hundred eighty-two subjects were seen, a 91.4% response rate. Subjects were divided by World Health Organization cardiovascular questionnaire criteria, history, examination, and coded 12-lead electrocardiogram into four groups: 1) those 70-79 years of age with evidence of CHD; 2) those 80 years and older with evidence of CHD; 3) those 70-79 years of age free of CHD; and 4) those 80 years and older free of clinical CHD. MEASUREMENTS: Mean values and distributions of cholesterol, high-density lipoprotein (HDL) cholesterol, apolipoproteins (apos), triglycerides, insulin, glucose, anthropometric measurements, and psychosocial variables. RESULTS: In the initial analysis of variance there was a significant difference in the mean values among the four groups for body mass index (BMI), HDL cholesterol, apo A1, and triglycerides. Using the Duncan procedure, the mean value of HDL cholesterol in the group 80 years and older with no evidence of clinical CHD was significantly higher than in each of the other groups. The group 80 years and older without clinical CHD had a significantly higher mean value for apo A1 and significantly lower mean values for triglycerides and BMI than the group 70-79 years old with CHD (p < 0.05). Three-factor analysis of variance showed those free of clinical CHD had significantly higher values of HDL cholesterol (P = 0.024) and apo A1 (P = 0.022), and lower values of BMI (P = 0.017) and triglycerides (P = 0.018) compared with those who had CHD after controlling for age and sex. Those 80 years and older had lower values of BMI (P = 0.001) and triglycerides (P = 0.018) than those 70-79 years old after controlling for CHD and sex. The group who were 80 years and older and free of clinical CHD had a significantly narrower distribution of values for insulin (P < 0.001), glucose (P = 0.001), diastolic blood pressure (P = 0.001), BMI (P = 0.001), and waist-hip ratio (P = 0.002) when compared with those 80 years and older with CHD; a significantly narrower distribution of values for insulin (P = 0.024), glucose (P = 0.003), and BMI (P = 0.002) when compared with those 79-79 years old with CHD and a significantly narrower distribution of glucose (P = 0.002) and BMI (P = 0.014) when compared with those 70-79 years old and free of clinical CHD. CONCLUSION: Those 80 years and older who were free of clinical CHD were characterized by differences in lipid and anthropometric values, particularly higher HDL cholesterol and apo A1 levels. Results were also consistent with this survivor group maintaining tighter homeostatic control over a number of variables.

Aged↗

PubMed1993

A factor(s) from a trophoblast cell line increases tyrosine hydroxylase activity in fetal hypothalamic cell cultures.

We previously reported that a factor(s) from rat choriocarcinoma (Rcho-1) cells suppresses circulating PRL levels and increases tyrosine hydroxylase activity in tuberoinfundibular dopaminergic neurons in vivo. The purposes of this study were to determine whether this factor(s) increases tyrosine hydroxylase activity in fetal hypothalamic cells in vitro and to evaluate its chemical nature. The Rcho-1 cells are of placental origin and have the capacity to differentiate into giant cells and produce members of the placental PRL family. MMQ cells, a pituitary cell line that secretes PRL, and HRP-1, a placental cell line that does not produce any known members of the PRL family, were used as control cells. Tyrosine hydroxylase activity was assessed by incubation of hypothalamic cells for 1 h with 100 microM brocresine, an inhibitor of aromatic L-amino acid decarboxylase. Tyrosine hydroxylase activity was increased in a density-dependent manner when Rcho-1, but not HRP-1 or MMQ, cells were cocultured with hypothalamic cells for 24 h. Control and Rcho-1-stimulated tyrosine hydroxylase activities were markedly reduced with 1 mM alpha-methyl-p-tyrosine, a specific inhibitor of tyrosine hydroxylase. Tyrosine hydroxylase activity was not altered when hypothalamic cells were incubated for 24 h with rat PRL or recombinant rat placental lactogen-I, whereas a 24-h stimulation with 100,000 Rcho-1 cells and a 1-h stimulation with 5 mM (Bu)2cAMP increased tyrosine hydroxylase activity 3.7- and 3-fold, respectively. The magnitudes of the increase in tyrosine hydroxylase activity were similar when hypothalamic cells were cocultured with Rcho-1 cells for 1 and 24 h. Acetic acid extracts of Rcho-1, but not HRP-1 or MMQ, cells increased tyrosine hydroxylase activity within 1 h in a concentration-dependent manner. The 3-fold increase in tyrosine hydroxylase activity observed with 500,000 Rcho-1 cell equivalents was markedly reduced with 1 mM alpha-methyl-p-tyrosine. The mol wt range of the tyrosine hydroxylase-activating factor(s) (THAF) was estimated using ultrafiltration membranes. The majority of activity was found in the eluate from a 1,000 mol wt cut-off membrane. THAF activity in Rcho-1 cell extracts was decreased by preincubation with pronase, a nonspecific proteolytic enzyme, suggesting that the factor(s) is a peptide. THAF was resistant to inactivation by trypsin or chymotrypsin pretreatment. However, both enzymes destroyed the ability of pituitary adenylate cyclase-activating peptide, either alone or with Rcho-1 cell extracts, to increase tyrosine hydroxylase activity. Oxidation of Rcho-1 cell extracts with performic acid abolished THAF activity.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1993

Pregnancy lactogens in the rat conceptus and fetus: circulating levels, distribution of binding, and expression of receptor messenger ribonucleic acid.

To clarify the roles of the rat placental lactogens in embryogenesis and fetal development, we measured the concentrations of rat placental lactogen-II (rPL-II) in fetal rat serum and examined the distribution and expression of rPL-I- and rPL-II-binding sites in rat uteroplacental and fetal tissues. The concentration of rPL-II in fetal rat serum on day 20 of gestation was 28.3 +/- 0.8 ng/ml (mean +/- SEM; n = 6), approximately 1/14th its concentration in maternal serum (398.3 +/- 45.3 ng/ml; n = 6). In the midgestational uterus and placenta, rat PL-I bound specifically to mesometrial decidua and to a capsular layer of stroma overlying the antimesometrial decidua. The binding of radiolabeled rPL-I to these tissues was inhibited by unlabeled rat PRL and human (h) GH, but not by rat GH, suggesting that the rPL-I-binding sites are lactogenic in nature. In the late gestational fetus, rat PL-II bound specifically to fetal adrenal, kidney, small intestine, liver, and pancreas; its binding, like that of rPL-I, was inhibited by rPRL, but not by rGH. rPL-II-binding sites in fetal adrenal were detected as early as day 16, whereas rPL-II-binding sites in fetal kidney and small intestine were not demonstrable until day 18. Lactogenic binding sites in fetal liver and pancreas did not appear until days 19-20. The relative amounts of specific binding of rPL-II to fetal tissues correlated positively with tissue levels of expression of the 4.2- and 1.8-kilobase PRL receptor mRNA transcripts. Radiolabeled hGH, which interacts with somatogenic receptors as well as lactogenic receptors, bound specifically to mesometrial decidua, fetal adrenal, kidney, small intestine, liver, and pancreas. In addition, radiolabeled hGH bound specifically, but with low intensity, to fetal brain. In mesometrial decidua and fetal adrenal, kidney, and small intestine, the binding of hGH was blocked by rPL-II and rPRL, but not by rGH or ovine GH, suggesting the predominance of lactogenic receptors. In contrast, in fetal brain, the binding of hGH was inhibited by rGH, but not by rPL-II, suggesting that the fetal brain contains somatogenic receptors. The presence of rPL-I-binding sites in maternal decidua suggests a paracrine role for the hormone in decidual function at midgestation. The presence of rPL-II in fetal serum and the widespread distribution of rPL-II-binding sites in fetal tissues indicate a role for rPL-II in fetal development.

Animals↗

PubMed1993

Rat placental lactogen-I binds to the choroid plexus and hypothalamus of the pregnant rat.

Recent findings suggest that placental lactogen has a role in the regulation of hypothalamic function during pregnancy. To explore the mechanisms by which placental hormones may exert effects in the maternal central nervous system, we have examined the binding of rat placental lactogen-I (rPL-I) to brain slices from pregnant rats at mid- and late gestation. The binding of rPL-I to maternal rat brain was compared with that of human GH (hGH). Radiolabelled rPL-I bound specifically to ependymal cells of the choroid plexus in the lateral ventricles and in the roof of the third ventricle. The binding of 125I-labelled rPL-I was inhibited by unlabelled rPL-I, hGH or rat prolactin but not by rat GH, indicating that rPL-I and rat prolactin interact with a common binding site in maternal rat brain. Radiolabelled hGH bound to the choroid plexus and to ependymal cells lining the third ventricle in the region of the arcuate nucleus. In addition, hGH bound specifically to the ventromedial nuclei and to the medial preoptic area of the hypothalamus. The binding of radiolabelled hGH to all brain regions was inhibited by unlabelled rPL-I as well as hGH, indicating that rPL-I competes for lactogenic binding sites in the hypothalamus as well as the choroid plexus of the pregnant rat. These findings suggest potential mechanisms by which placental hormones may exert direct effects on the maternal central nervous system during pregnancy. The precise functions and roles of the PL-I binding sites in maternal choroid plexus and hypothalamus remain to be explored.

Animals↗

PubMed1992

Plasma non-cholesterol sterols in patients with non-insulin dependent diabetes mellitus.

Plasma plant sterol concentrations (an index of cholesterol absorption efficiency) and plasma lathosterol concentration (an index of cholesterol synthesis rate) were measured in 52 patients with non-insulin dependent diabetes mellitus (NIDDM) and 36 non-diabetic controls. Plasma plant sterol concentrations were significantly (P less than 0.01) lower in diabetic patients (campesterol: men -36%, women -48%; betasitosterol: men -35%, women -42%). Fasting serum insulin levels were inversely correlated with plasma plant sterol concentrations in diabetic patients (campesterol: r = -0.347, P = 0.012; betasitosterol: r = -0.345, P = 0.012) and in non-diabetic men (campesterol: r = -0.578, P = 0.039; betasitosterol: r = -0.702, P = 0.008). Serum insulin levels were also correlated significantly with plasma lathosterol concentration in diabetic patients (r = 0.295, P = 0.034). The results of this study suggest that absorption of plant sterols and possibly cholesterol from the diet may be reduced in hyperinsulinemic diabetics.

Adult↗

PubMed1992

Cholesterol metabolism in distance runners.

Faecal steroid excretion, including betasitosterol excretion, whole-body cholesterol synthesis, plasma lipids, and lipoprotein concentrations and habitual diet, were determined in 14 male distance runners and 14 sedentary men. The proportion of cholesterol-derived steroids excreted as bile acids, and the quantity of betasitosterol excreted in the faeces were significantly (P less than 0.05) higher in the runners compared with the sedentary men. Faecal betasitosterol excretion and the proportion of cholesterol-derived steroids excreted as bile acids were correlated significantly in the distance runners and the sedentary men (r = 0.774, n = 28, P less than 0.001). These results suggest that greater dietary intake of plant sterols may contribute to the higher proportion of cholesterol-derived steroids excreted as bile acids in distance runners.

Adult↗

PubMed1991

Plasma noncholesterol sterols in male distance runners and sedentary men.

Plasma lathosterol concentration is taken to be an index of the rate of cholesterol synthesis and plasma concentrations of plant sterols just as campesterol and betasitosterol are taken to be indeces of cholesterol absorption efficiency. These noncholesterol sterols were measured in plasma from 14 male distance runners and 10 sedentary men. Plasma lathosterol concentration was 30% lower (P less than 0.02) and plasma betasitosterol concentration was 33% higher (P less than 0.02) in the runners compared to the sedentary men. Plasma concentrations of lathosterol and plant sterols were inversely and significantly (P less than 0.05) correlated in both the runners and the sedentary men. Plasma plant sterol concentrations were correlated positively and significantly (P less than 0.01) with plasma high density lipoprotein cholesterol (HDL-C) concentrations in the runners and sedentary men combined. These findings suggest that more efficient cholesterol absorption may lead to higher plasma plant sterol concentrations and may contribute to lower cholesterol synthesis rates, reduced concentrations of plasma lathosterol and higher plasma HDL-C concentration in distance runners.

Adult↗

PubMed1991

Use of benzodiazepines in private nursing homes: a drug 'index' as an indicator of quality in nursing home care.

Benzodiazepines have attracted criticism as drugs on which patients can become dependent. This paper examines how widely these drugs were prescribed by GPs to patients in 15 Oxfordshire nursing homes during 1987. About one in three patients was found to have such a prescription. The potential relationship between benzodiazepine prescribing and rate of incidents in the homes did not prove clear-cut, although pointing toward a slight negative correlation. Duration of action of the type of benzodiazepine had relevance. An index of benzodiazepine prescriptions per resident was derivable (the 'benzodiazepine index'). This provided an indicator of quality of care which could be used to compare practice between different nursing homes.

Aged↗

PubMed1991

Fecal bile acid concentration in distance runners.

Fecal bile acid concentration, fecal characteristics, bowel habits and habitual food intake were measured in male distance runners (n = 14) and sedentary men (n = 14). Fecal bile acid concentration was significantly (p less than 0.05) lower and stool weight, frequency of defecation and daily intake of fibre, carbohydrate, and protein were significantly (p less than 0.01) higher in the runners. After adjustment for differences in dietary fibre intake, fecal bile acid concentration was no longer significantly different between the distance runners and the sedentary men, but frequency of defecation remained significantly (p less than 0.05) higher in the runners. This study has identified lower fecal bile acid concentration in distance runners, which was probably due mainly to dilution of colon contents by higher consumption of dietary fibre. These findings may be relevant to the reduced incidence of colon cancer in physically active subjects.

Adult↗

PubMed1991

Molecular cloning and expression of rat placental lactogen-Iv, a variant of rPL-I present in late pregnant rat placenta.

Late pregnant rat placenta was found to contain a messenger RNA (mRNA) that encodes an additional member of the prolactin-growth hormone family. This polypeptide was detected by hybridization of complementary DNA (cDNA) for rPL-I to a 1 kilobase mRNA transcript in late pregnant rat placenta. A cDNA clone for the new polypeptide was isolated from a phage lambda-gt10 library containing cDNA synthesized from day 18 rat placental mRNA. Sequencing of the day 18 cDNA clone revealed that it was most closely related structurally to rPL-I and at the amino acid terminal was identical to the rPL-I variant (rPL-Iv). The sequence of rPL-Iv (223 amino acids) is 85% homologous to rPL-I (230 amino acid). There are 71 base pair changes (85% nucleotide homology) between rPL-Iv and rPL-I which are not confined to any specific region of the molecule and which result in 36 amino acid changes. In vitro translation of rPL-Iv mRNA produced by transcription of the cDNA template yielded a 26 kilodalton polypeptide, the size of the expected precursor protein. In situ hybridization studies indicated that mRNA for rPL-Iv was present primarily in cytotrophoblasts of the basal zone as early as day 15 of gestation with some hybridization in a few giant cells as well.

Amino Acid Sequence↗

PubMed1990

Effect of eicosapentaenoic acid on restenosis rate, clinical course and blood lipids in patients after percutaneous transluminal coronary angioplasty.

In order to study the effects of eicosapentaenoic acid (Maxepa), Maxepa placebo and aspirin/dipyridamole combination on the clinical course and restenosis rate of atherosclerotic lesions after percutaneous transluminal coronary angioplasty 79 men and 29 women were randomly divided into three treatment groups and restudied angiographically within one year of the procedure. Angina recurred less in the Maxepa group than in the other groups, although not statistically so. Restenosis rate was significantly reduced in the Maxepa group (11%) compared to the placebo group (30%) but, while less, was not significantly lower than in the aspirin/dipyridamole group (17%). Maxepa treatment appears to reduce restenosis rate of coronary artery lesions after percutaneous transluminal coronary angioplasty and may be an acceptable and equally effective alternative therapy to aspirin/dipyridamole.

Adult↗

PubMed1990

Molecular cloning and expression of rat placental lactogen-I complementary deoxyribonucleic acid.

A full-length cDNA clone for rat placental lactogen I (rPL-I) has been isolated from a phage lambda gt11 library containing cDNA synthesized from day 11 rat placental mRNA. By Northern blot analysis the rPL-I cDNA clone hybridizes to a 1.0-kilobase placental mRNA and appears as early as day 10 of gestation. Maximal expression of this mRNA was observed in day 11 and 12 placenta, and faint hybridization of the rPL-I cDNA was also detected in day 18 to term placenta. In contrast, the mouse clone hybridized to mRNA for mouse PL-I (mPL-I) only in day 10 mouse placenta (9). In vitro translation of rPL-I mRNA produced by transcription of the cDNA template yielded a 27-kDa polypeptide the size of the expected precursor protein which was immunoprecipitated by a monoclonal antibody to rPL-I. The rPL-I cDNA nucleotide sequence has been determined. The sequence is very similar to that for mPL-I and contains an open reading frame encoding a polypeptide of 230 amino acids compared to 224 for mPL-I. Comparison of the predicted primary translation product of rPL-I mRNA with that of mPL-I mRNA revealed that rPL-I shares 73% identity to mPL-I at the amino acid level. The predicted rPL-I protein shares 41% amino acid identity with rPL-II precursor, 24% with rat prolactin-like protein A, 26% with rat prolactin-like protein B, and 31% with rat PRL. In situ hybridization studies indicated that mRNA for rPL-I was present in a few rapidly dividing cells as early as day 8 of gestation, and by day 9 could be localized to giant cells which surround the conceptus.

Amino Acid Sequence↗