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C C Moore

Publications and source records attributed to C C Moore.

35 records · Page 2Linked to original sources
PubMed1993

Structure and function of the hepatic form of 11 beta-hydroxysteroid dehydrogenase in the squirrel monkey, an animal model of glucocorticoid resistance.

Both cortisol and aldosterone bind to and activate the mineralocorticoid receptor. Cortisol concentrations are generally 100- to 200-fold higher than aldosterone concentrations, yet mineralocorticoids clearly exert effects different from glucocorticoids. One hypothesis is that 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD), which converts cortisol to biologically inactive cortisone, protects the mineralocorticoid receptor from cortisol. The circulating concentrations of cortisol in the squirrel monkey are 20- to 50-fold higher than human cortisol concentrations, yet this animal has no evidence of glucocorticoid or mineralocorticoid excess. We used this experiment of nature to test the hypotheses that the known (hepatic) form of 11 beta-HSD protects renal mineralocorticoid receptors from the action of cortisol and that it modulates glucocorticoid concentrations in target tissues. Using a long oligonucleotide based on the rat sequence, we cloned the squirrel monkey 11 beta-HSD complementary DNA and gene. The encoded monkey amino acid sequence is 75% and 91% identical to the corresponding rat and human sequences, respectively. The tissue abundance of the messenger RNA for the monkey enzyme was similar to or less than that seen for the rat and human enzymes. Both the monkey and human 11 beta-HSD complementary DNAs were cloned into an expression vector and used to transfect cultures of Chinese hamster ovary cells. Both vectors were transcribed and translated into equivalent amounts of 11 beta-HSD enzyme. The monkey enzyme was slightly more efficient than the human enzyme in converting [3H]cortisol to cortisone, and estimates of the Michaelis-Menten constant and maximum velocity of both enzymes are similar. These data indicate that the abundance and activity of the hepatic form of 11 beta-HSD are insufficient to inactivate the very high concentrations of cortisol in the squirrel monkey, suggesting that this form of 11 beta-HSD does not defend the mineralocorticoid receptor or protect tissues from high cortisol concentrations. Rather, this enzyme appears to favor conversion of cortisone to cortisol, thus maximizing tissue concentrations of cortisol to overcome glucocorticoid resistance associated with a 50% reduction in glucococorticoid receptors.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1992

Infection of cultured human adrenal cells by different strains of HIV.

OBJECTIVE: To determine whether human adrenal cells can be infected by HIV. METHODS: Cultured human fetal adrenal cells and the SW13 human adrenocortical carcinoma cell line were inoculated with several HIV-1 and HIV-2 strains. Virus replication was detected by viral core antigen enzyme-linked immunosorbent and reverse transcriptase assays. CD4 expression was measured by Northern blot and polymerase chain reaction procedures. RESULTS: HIV infection of these adrenal cells was detected and was most evident after cocultivation of the inoculated cells with peripheral blood mononuclear cells. Infection does not involve the CD4 molecule, which is not expressed by these adrenal cells. The relative level of HIV replication depended on the viral strain used. Virus production occurred best in cells that maintained evidence of adrenal cell function. Infection did not appear to disturb steroidogenesis measured in the cells. CONCLUSIONS: These observations indicate that human adrenal cells are susceptible to HIV infection, and provide further evidence of the polytropic nature of the virus.

Adrenal Cortex↗
PubMed1992

Identification of positive and negative placenta-specific basal elements and a cyclic adenosine 3',5'-monophosphate response element in the human gene for P450scc.

The chronic regulation of steroiodgenesis is mediated principally by transcriptional regulation of the genes encoding the various steroidogenic enzymes. The cholesterol side-chain cleavage enzyme, P450scc, is rate limiting and hormonally regulated in a tissue-specific fashion. Human placental steroidogenesis is regulated by LH and hCG through increased intracellular cAMP, and forskolin and 8-bromo-cAMP increase the abundance of human P450scc mRNA in human JEG-3 choriocarcinoma cells. We transfected JEG-3 cells with 24 promoter/reporter constructions to examine the tissue-specific and hormonally induced transcription of the human P450scc gene in these cells. A reporter construction containing only bases -79 to +49 of the human P450scc gene was expressed in JEG-3 cells. This basal expression was increased by four elements, especially by a powerful element between -152 to -142. Adding DNA sequences to -177 suppressed the basal expression seen with the -152 construction, indicating that a repressor element lies between -177 and -152. Thus, basal expression of the human P450scc gene in JEG-3 cells is mediated by the interplay of several separate cis-acting DNA elements. Forskolin induction was conferred by sequences between -108 and -89. The mechanism for cAMP induction appears to be direct, as this induction is rapid and is not blocked by inhibiting protein synthesis with cycloheximide. Gel mobility shift experiments identified six specific DNA-protein complexes. Five of these complexes correlate closely with the basal transcription activities identified by the reporter assays. The powerful basal element, the repressor element, and the cAMP element differ from those identified by similar experiments in mouse adrenal Y1 cells, suggesting that the human P450scc gene is regulated by the tissue-specific use of different regulatory elements.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1991

Missense mutation serine106----proline causes 17 alpha-hydroxylase deficiency.

Steroid 17 alpha-hydroxylase deficiency is caused by defects in cytochrome P450c17, the single enzyme that has 17-alpha hydroxylase and 17,20-lyase activities. We describe a rapid and efficient polymerase chain reaction tactic for identifying these genetic lesions and identify Ser106----Pro as the cause of 17 alpha-hydroxylase deficiency in two unrelated homozygous patients from Guam. We used site-directed mutagenesis of the normal P450c17 cDNA to construct the Pro106 mutant, and expressed both the normal and mutant sequences in monkey COS-1 cells and in yeast. Expression of the normal sequence permitted the cells to convert pregnenolone to 17-OH pregnenolone, progesterone to 17-OH progesterone, and 17-OH pregnenolone to dehydroepiandrosterone, showing the normal sequence conferred both 17 alpha-hydroxylase and 17,20-lyase activities. Expression of the mutant sequence generated P450c17 mRNA, but conferred none of these activities, proving that the Ser106----Pro mutation abolished the 17 alpha-hydroxylase and 17,20-lyase activities. An HhaI restriction site created by the mutation should permit screening of large populations.

Adolescent↗
PubMed1991

Lipoid pneumonia in infants: a radiological-pathological study.

A series of nine infants, 2-8 months of age, with a history of animal or vegetable fat intake within 10 days after birth, is presented. The infants developed respiratory problems and failure to thrive. Plain films and computed tomography showed areas of consolidation in the medial-posterior parts of the lungs. The areas of consolidation showed three types of changes at computed tomography. Attenuation measurements did not reveal fat. To establish the diagnosis, fine needle aspiration biopsy, tru-cut biopsy and/or open lung biopsy was done in eight infants and bronchopulmonary lavage in one patient. The pathological findings were an intense lymphocytic infiltration with scattered granulomas which contained lipid deposit.

Biopsy, Needle↗
PubMed1991

The role of transcriptional regulation in steroid hormone biosynthesis.

The regulated expression of the genes encoding the various steroidogenic enzymes is a crucial component in the control of steroid hormone biosynthesis. Tissue-specific transcription of each of the steroidogenic enzyme genes determines the array of enzymes present within a steroidogenic tissue, and therefore the types of steroid hormones the tissue produces. Transcriptional regulation also determines developmental changes in the steroid hormones synthesized by steroidogenic tissues and for the quantitative regulation of steroid hormones necessary for reproduction and for maintaining physiological homeostasis. The molecular mechanisms governing transcriptional regulation of steroidogenic enzyme genes is now being studied. The results so far indicate that, like most other genes, transcription of steroidogenic enzyme genes is regulated by cis-elements in the 5' flanking DNA of the genes that bind trans-acting proteins found in the nucleus. Several types of cis-elements have been identified: elements responsible for basal transcription, for induction by cAMP, and for both basal and cAMP induction. Some of the basal cis-elements identified may have a role in tissue-specific transcription of certain steroidogenic enzyme genes in steroidogenic tissues. We have also identified regions in both the human P450scc and human P450c17 promoters that repress transcription when activated by the Ca2+/protein kinase C intracellular second messenger system used by angiotensin II. This review summarizes our current understanding of transcriptional regulation of the steroidogenic enzyme genes.

Animals↗
PubMed1990

The role of routine radiographic screening of boys with hypospadias: a prospective study.

One hundred fifty-three asymptomatic boys with hypospadias were screened routinely by intravenous pyelography and voiding cystourethrography. Urinary tract abnormalities were found in 23.53%. Significant abnormalities were found in 11% on initial examination, and on follow-up, a further 4.5% required later surgery. The overall incidence of surgical interference, not including hypospadias repair, was 11.76%. Thus, routine urinary tract radiological screening in boys with hypospadias is recommended.

Humans↗
PubMed1990

Human P450scc gene transcription is induced by cyclic AMP and repressed by 12-O-tetradecanoylphorbol-13-acetate and A23187 through independent cis elements.

Long-term regulation of mammalian steroid hormone synthesis occurs principally by transcriptional regulation of the gene for the rate-limiting cholesterol side-chain cleavage enzyme P450scc. Adrenal steroidogenesis is regulated primarily by two hormones: adrenocorticotropin, which works via cyclic AMP (cAMP) and protein kinase A, and angiotensin II, which works via Ca2+ and protein kinase C. Forskolin and 8-bromo-cAMP stimulated, while prolonged treatment with a phorbol ester (12-O-tetradecanoylphorbol-13-acetate [TPA]) and a calcium ionophore (A23187) additively suppressed accumulation of endogenous P450scc mRNA in transformed murine adrenal Y1 cells. In Y1 cells transfected with 2,327 base pairs of the human P450scc promoter fused to the bacterial gene for chloramphenicol acetyltransferase (CAT), forskolin increased CAT activity 900% while combined TPA plus A23187 reduced CAT activity to 15% of the control level. Forskolin induced the P450scc promoter as rapidly as a promoter containing two cAMP-responsive elements fused to a simian virus 40 promoter, a system known to respond directly to cAMP. Basal expression was increased by sequences between -89 and -152 and was increased further by sequences between -605 and -2327. This upstream region also conferred inducibility by cAMP. TPA plus A23187 transiently increased CAT activity before repressing it, reflecting the complex actions of angiotensin II in vivo. Repression by prolonged treatment with TPA plus A23187 was mediated by multiple elements between -89 and -343. Induction of CAT activity by forskolin was not diminished by treatment with TPA plus A23187, nor were the regions of the promoter responsible for regulation by the two pathways coisolated. Thus, the human gene for P450scc is repressed by TPA plus A23187 by mechanisms and sequences independent of those that mediate induction by cAMP.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1990

Tissue-specific, cyclic adenosine 3',5'-monophosphate-induced, and phorbol ester-repressed transcription from the human P450c17 promoter in mouse cells.

Cytochrome P450c17 is the single microsomal enzyme catalyzing steroid 17 alpha-hydroxylase and 17-20-lyase activities. It is expressed and regulated by tropic hormones in the human adrenal and gonads, but is not expressed in the placenta. To study the transcriptional regulation of the human P450c17 gene, we constructed 11 plasmids containing serial deletions of its 5' nontranslated region driving expression of the chloramphenicol acetyltransferase (CAT) reporter gene. These constructs were transfected into mouse adrenal Y1 and testis MA-10 cells and incubated with forskolin, 8-bromo-cAMP, or 12-O-tetradecanoyl-phorbol-13 acetate (TPA) for 12 h. Interpretation of results from standard constructions was difficult, apparently because some transcription was incorrectly initiated by DNA sequences in the vector. Therefore, we built a modified CAT reporter vector that eliminated detectable read-through transcription. In Y1 cells, the basal activity of constructs containing from -82 to -184 basepairs (bp) of 5' flanking DNA was between 80-150% of the promoterless control. Constructs containing at least -235 bp of this DNA expressed CAT at 540% of the control value, but addition of sequences to -774 had no further effect. Forskolin increased the expression of CAT activity to 300% above basal with constructions containing DNA from -184 to -774 bp. Constructs containing between -184 and -310 bp expressed CAT at 50% of the forskolin-induced levels in cells treated with TPA. Both basal and cAMP-induced expression were much lower in MA-10 cells than in Y1 cells and increased with increasing promoter length to -774.(ABSTRACT TRUNCATED AT 250 WORDS)

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1989

Congenital gastric outlet obstruction.

Two additional cases of congenital gastric outlet obstruction are presented. A comprehensive review of the literature was undertaken and as a result a classification for congenital gastric outlet obstruction is suggested. The management of the cases reported in the literature has also been reviewed together with the genetics of pyloric atresia and associated dermatologic lesions. Guidelines are given for the management of congenital gastric outlet obstruction with and without associated, inherited dermatologic conditions.

Child, Preschool↗
PubMed1984

A clinically applicable exsanguination shock model in swine.

In order to evaluate treatments of the rapid exsanguination seen in the majority of civilian trauma or combat fatalities, we designed a rapid exsanguination, conscious, unheparinized 100% fatal porcine hemorrhage model. Immature female swine were bled 60% of their estimated blood volume 5 days after placement of a bleeding catheter. The change in arterial base excess concentration (BE) and hematocrit (Hct) was followed after hemorrhage. Variables were bleeding time (120, 60, 30, and 15 min) and catheter placement (carotid, 7 cases; and distal aorta, 24 cases). The Hcts before hemorrhage were similar in both groups. The time for removal of 60% EBV for routine mortality was longer with the carotid (60 min) versus the distal aorta (15 min) catheter group. At autopsy the carotid catheters partially obstructed the orifice of the opposite carotid. In the aortic group, a rate of hemorrhage of 2.65 +/- 0.97 ml/kg/min was required to provide the ischemia necessary for 100% mortality. The BE after hemorrhage was significantly different in survivors versus nonsurvivors. A carotid artery catheter that extends into the porcine brachiocephalic artery appears to cause artifactual mortality by interfering with blood flow to the opposite carotid. A conscious, unheparinized, and reliably fatal exsanguination model has been standardized. The animal must sustain a 60% EBV loss from the distal aorta in 15 min.

Animals↗
PubMedDate not supplied

Calculation of three-dimensional left ventricular strains from biplanar tagged MR images.

The noninvasive measurement of time-resolved three-dimensional (3D) strains throughout the myocardium could greatly improve the clinical evaluation of cardiac disease and the ability to mathematically model the heart. On the basis of orthogonal arrays of tagged magnetic resonance (MR) images taken at several times during systole, such strains can be determined, but only after heart motion through the image planes is taken into account. An iterative material point-tracking algorithm is presented to solve this problem. It is tested by means of mathematical models of the heart with cylindric and spherical geometries that undergo deformations and bulk motions. Errors introduced by point-tracking interpolation were found to be negligible compared with those due to marker identification on the images. In a human heart studied with this technique, the corrected radial strains at the left ventricular base were approximately 2.5 times the two-dimensional estimates derived from the fixed image planes. The authors conclude that material point tracking allows accurate, time-resolved 3D strains to be calculated from tagged MR images, and that prior correction for motion of the heart through image planes is necessary.

Heart Ventricles↗