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C J Jones

Publications and source records attributed to C J Jones.

At least 289 records · Page 16Linked to original sources
PubMed1976

An ultrahistochemical study of the distribution of acid and alkaline phosphatases in placentae from normal and complicated pregnancies.

The subcellular localisation of acid and alkaline phosphatase has been studied in the trophoblast of placentae from both normal and complicated pregnancies. In placentae from uncomplicated pregnancies the number of trophoblastic acid-phosphatase-containing organelles decreases progressively as gestation proceeds whilst alkaline-phosphatase activity, although abundant at term, could not be demonstrated during the early stages of pregnancy. The acid-phosphatase-containing organelles are of two types; one is a small round body which is probably a lysosome whilst the other is a multivesicular body. The alkaline phosphatase is distributed mainly on the syncytial microvilli and plasma-membrane. It is suggested that the marked lysosomal activity during early pregnancy is related to the architectural refashioning of the placenta during this period and that there are two phosphatase-linked transfer systems in the trophoblast, one dependent upon acid-phosphatase-containing multivesicular bodies and being utilised during early pregnancy and the other reliant upon alkaline phosphatase and dominating during the second half of gestation. In placentae from prolonged pregnancies there is a further decrease in trophoblastic acid phosphatase and, usually, a continuing increase in alkaline-phosphatase activity. In placentae from babies of low birth weight this trend is sometimes reversed and alkaline-phosphatase activity either disappears or its reaction product diffuses throughout the syncytium; this is usually accompanied by a marked increase in the number of acid-phosphatase-containing multivesicular bodies. Placentae from women with pre-eclampsia show no loss of alkaline-phosphatase activity but are characterised by an increased number of lysosomal bodies.

Acid Phosphatase↗
PubMed1976

An ultrastructural and ultrahistochemical study of the placenta of the diabetic woman.

An ultrastructural and ultrahistochemical study has been made of placentae from seven women, all of whom were established diabetics before the onset of pregnancy. None of these women had suffered from any of the hypertensive complications of pregnancy. Patchy focal syncytiotrophoblastic necrosis was evident and indirect evidence of syncytial damage was seen in the form of marked cytotrophoblastic hyperplasia. The syncytial necrosis appeared to be lysosomally mediated, possibly as a result of altered intracellular pH. Occasional cytotrophoblastic cells also showed degenerative changes. Most of the villous trophoblast was, however, morphologically normal and showed features suggestive of normal or increased synthetic, transfer and excretory activity. Focal thickening of the villous trophoblastic basement membrane was seen and this did not appear to be due to deposition of immune complexes. The endothelial cells of the villous capillaries appeared unduly immature but no evidence was seen of immune complex deposition in these vessels or of diabetic angiopathy. It is concluded that the diabetic's placenta shows a consistent pattern of abnormalities which appear to be a direct result of the diabetic state.

Acid Phosphatase↗
PubMed1976

The pharmacology and pharmacokinetics of azapropazone - a review.

The pharmacology and pharmacokinetic properties of azapropazone, a new anti-inflammatory analgesic, are reviewed. Anti-inflammatory activity was assessed by standard in vivo and in vitro methods. The drug was shown to have definite activity with a potency approximately half that of phenylbutazone. Azapropazone was absorbed from the gastro-intestinal tract in animals and man, although wide inter-species variation in pharmacokinetic properties was noted. In man, the biological half life was approximately 20 hours. Azapropazone is not extensively metabolised and most metabolites have been identified and assayed.

Animals↗
PubMed1976

Placental changes in gestational diabetes. An ultrastructural study.

A light microscopic, an electron microscopic, and a ultrahistochemical study have been made of seven placentas from women with mild and excellently controlled chemical gestational diabetes. Only one placenta showed no significant abnormality; the remainder showed, to a varying degree, changes in the syncytiotrophoblast, cytotrophoblast, trophoblastic basement membrane, and fetal vessels. These abnormalities were identical to and in some cases as severe as those found in placentas from women with longstanding, moderately controlled, overt diabetes mellitus. These findings indicate that control of hyperglycemia only partially prevents the development of placental abnormalities which must be due to some other constituent factor of the diabetic state.

Alkaline Phosphatase↗
PubMed1975

Cervical neoplasia in residents of a low-income housing project: an epidemiologic study.

In 1969, a published report estimated that the incidence of cervical cancer in a low-income housing project in Atlanta, G Georgia, might be of epidemic proportion. In 1971, we surveyed this housing project to determine if the prevalence rate of cervical neoplasia was unusually high during the period January, 1969, through September, 1971. From the survey we determined the number of women at risk for cervical neoplasia, and we determined the number of women who had cervical neoplasia from the Tumor Registry at Grady Memorial Hospital. The over-all cervical dysplasia rate was 63/1,000. The over-all prevalence rate of cervical carcinoma in situ was 11/1,000. These rates were compared with rates in two studies which also dealt with the prevalence of cervical neoplasia in low-income black populations. The rates in all three studies were comparable. We conclude that the high rates do not necessarily signify an epidemic, but we suspect that the prevalence of cervical neoplasia in low-income black women is much higher than previously estimated.

Adolescent↗
PubMed1975

Growth hormone, cyclic nucleotides and the rapid control of translation in heart muscle.

Perfused rat heart incorporated L-[14C]tyrosine into protein at a constant rate for up to 75 min. A purified bovine growth-hormone preparation (1 mug/ml) stimulated the incorporation to a new constant rate that was more than three times the control rate by 10 min after hormone addition to perfusate. The hormone, however, did not alter the intracellular tracer amino acid pool, and the relationship of this to the aminoacyl-tRNA precursor pool is discussed. It is concluded that the increased incorporation largely reflected a rapid increase in protein synthesis at the ribosomes. Measurements of cyclic nucleotide contents during the perfusion showed that these appeared to vary in a systematic way during the perfusion. This strands in contrast with the constant values given by several other parameters measured in this preparation. Futher, the cyclic nucleotide variation seems to be independent of external effectors. The steady-state performance of the heart correlates more closely the [cyclic AMP]/[cyclic GMP] ratio than with the content of the individual cyclic nucleotides. At 10 min after the addition of growth hormone a slight decrese in cyclic AMP content and a large decrease in cyclic GMP were found, suggesting that the hormone's effect in stimulating protein synthesis may be mediated by a decrease in cyclic nucleotide concentrations or an increase in the [cyclic AMP]/[cyclic |p] ratio. The findings are also consistent with an intracellularly directed role for these nucleotides, and the possibility that the cyclic nucleotide changes are an indirect result of growth-hormone action is discussed.

Amino Acids↗
PubMed1975

No demonstrable effect of S-carboxymethylcysteine on clearance of secretions from the human lung.

The mucolytic efficacy of S-carboxymethylcysteine has been assessed in a double-blind crossover trial in 16 patients with chronic obstructive bronchitis. No significant difference was found between drug and placebo after four or seven days' treatment in the rate of clearance of secretions from the lung. This was measured by external counting of previously inhaled polystyrene tracer particles tagged with technetium-99m (99mTc). Lateral scans across the right chest after inhaling the aerosol showed equal penetration of particles towards the periphery of the lung in drug and placebo runs; this indicated that the airways had not been cleared of mucus by the drug. There was no significant difference between drug and placebo runs in the number of coughs or the weight and radioactive content of sputum voided or raised at the end of the run by chest percussion and postural drainage. Ventilatory capacity was not significantly changed nor was there any subjective improvement in the patients as a result of taking the drug.

Aged↗
PubMed1975

Leptospira fort-bragg isolated from a rat in Barbados.

Leptospira fort-bragg was isolated from the kidney tissue of a rat (Rattus rattus) trapped on a plantation in St. Philip Parish, Barbados. This constitutes the first reported isolation of this Autumnalis group serotype outside of the United States and its first known isolation from an animal species. Serologic evidence is presented which indicates that this serotype may be the cause of leptospiral infections in Barbadian cattle.

Animals↗
PubMed1969

Histochemical fluorescence studies on noradrenaline accumulation by Uptake 2 in the isolated rat heart.

1. The distribution of noradrenaline accumulated by Uptake(2) (Iversen, 1965) in the isolated perfused rat heart has been observed using histochemical fluorescence microscopy.2. On the basis of the technique used, noradrenaline seems to be predominantly associated with the cardiac muscle cells, but sympathetic nerves and other cardiac structures also serve as retention sites.3. Phenoxybenzamine, normetanephrine and perfusion with noradrenaline at 20 degrees C all decreased noradrenaline accumulation.4. Lowered temperature significantly increased the perfusion pressure and significantly decreased the [(14)C]-sorbitol space in perfused hearts.5. The implications of these results are discussed.

Animals↗
PubMedDate not supplied

Localisation of glycans in the placenta: a comparative study of epitheliochorial, endotheliochorial, and haemomonochorial placentation.

Specimens of mid-term (horse), near-term (pig, cow, sheep, mink) and term (human) placentae and associated tissues have been examined with a panel of 15 biotinylated lectins combined with an avidin-peroxidase revealing system. The aim of this study has been to analyse the expression of glycans at the materno-fetal interface in order to establish whether the morphological diversity exhibited by these six species is reflected by accompanying biochemical diversity, or whether similar types of glycan are expressed in tissues performing similar functions. Lectin staining intensity was scored in the following elements of the interhaemal placental barrier: maternal capillaries, maternal uterine epithelium, the materno-fetal interdigitating microvillous membrane (brush border in the human), trophoblast, and fetal capillaries. A high degree of biochemical diversity was found in the glycan expression of the various placental components within and among placental types. Each layer showed widely differing patterns of lectin binding between species, with only a few findings in common: 1) the relative lack of simple fucosyl termini, 2) the presence of non-bisected bi/tri-antennary N-glycan in most layers, 3) an abundance of terminal N-acetyl galactosamine, and 4) the restriction of high mannose glycans to intracellular granules. This diversity may be a mechanism to avoid hybridisation, although glycan patterns may change between conception and placental development, or it may have evolved as a consequence of morphological changes. It is possible that it may also be part of the cause, rather than the result, of the structural diversity that is so characteristic of mammalian placentation.

Animals↗
PubMedDate not supplied

Location of insulin receptors in the placenta and its progenitor tissues.

The insulin receptor gene is constitutively expressed, so the presence of insulin receptor proteins might be expected on all mammalian tissues, with the plasma membrane as the predominant site of receptor location. Results reviewed here indicate that insulin receptors are also present in all placental tissues and the placenta's progenitor tissues and cells, i.e., oocytes, spermatozoa, and preimplantation embryos, in most of the species studied. Receptor densities, however, vary among individual cells and cell types and at various developmental stages. Three aspects deserve emphasis. 1) In human placenta, the insulin receptor distribution pattern is characterized by a spatiotemporal change between first trimester and term. At the beginning of pregnancy, insulin receptors are found predominantly on the maternal side (apical membrane of syncytiotrophoblast, low density on cytotrophoblast); at term, however, they are on the fetal side (lining the fetal vessels). This suggests that, in the first trimester, maternal insulin regulates insulin-dependent processes, whereas, at term, it must be fetal insulin mainly controlling these processes. 2) The majority of insulin receptors is expressed on structures that are currently assumed to drive placental growth, i.e., syncytial sprouts and mesenchymal villi in first-trimester placentas and fetal endothelium at term. Therefore, we hypothesize a growth-promoting function, among others, of insulin on the placenta. 3) At present, no histologic evidence is available to demonstrate insulin receptors in structures commonly associated with receptor-mediated endocytosis. Whether placental insulin receptors are internalized, therefore, awaits clarification.

Animals↗