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Biomedical subjects

D Hodges

Publications and source records attributed to D Hodges.

36 records · Page 2Linked to original sources
PubMed1976

Uptake of (3H)progesterone and (3H)5alpha-dihydroprogesterone by rat tissues in vivo and analysis of accumulated radioactivity: accumulation of 5alpha-dihydroprogesterone by pituitary and hypothalamic tissues.

These in vivo studies explored the possibility that the metabolism of progesterone to 5alpha-dihydroprogesterone (5alpha-DHP) and 3alpha-hydroxy-5alpha-pregnan-20-one in hypothalamus and pituitary may influence gonadotropin release. [3H]progesterone or [3H]5alpha-DHP was injected iv into ovariectomized or ovariectomized-adrenalectomized rats for 10 0r 30 min. 3H content was determined for plasma, anterior pituitary, medial basal hypothalamus (MBH), cerebral cortex, muscle and uterus. Isotopic dilution analyses of the accumulated 3H were made for progesterone, 5alpha-DHP, 3alpha-hydroxy-5alpha-pregnan-20-one, 20alpha-dihydroprogesterone, 20alpha-hydroxy-5alpha-pregnan-3-one, and 5alpha-pregnane-3alpha, 20alpha-diol on samples from the 10 min groups. With progesterone injections, most of the tissue 3H was distributed among progesterone, 5alpha-DHP, and 3alpha-hydroxy-5alpha-pregnan-20-one. Progesterone was the predominant 3H-steroid in uterus, MBH, cerebral cortex and muscle. [3H]5alpha-DHP was the other major 3H-steroid in MBH and the predominant one in pituitary. In terms of tissue/plasma concentration comparisons, no tissue concentration of [3H]progesterone was greater than that in plasma except for MBH in the ovariectomized-adrenalectomized group. In contrast, [3H]5alpha-DHP levels in pituitary, MBH and cerebral cortex were many fold greater than those in plasma and muscle. MBH and pituitary levels were significantly greater than that in cerebral cortex. With 5alpha-DHP injections, most tissue 3H was associated with 5alpha-DHP and/or 3alpha-hydroxy-5alpha-pregnan-20-one. No [3H]progesterone was detected. [3H]5alpha-DHP predominated in pituitary and MBH, while 3alpha-hydroxy-5alpha-pregnan-20-one predominated in the others. In terms of tissue and plasma concentration comparisons, MBH, pituitary and cerebral cortical concentrations of [3H]5alpha-DHP were markedly higher than plasma, muscle, and uterine levels. Pituitary and MBH concentrations were also greater than that in cerebral cortex. Tissue levels of [3H]3alpha-hydroxy-5alpha-pregnan-20-one were not significantly greater than that in plasma. Thus, 10 min after injection of either [3H]progesterone or [3H]5alpha-DHP, high and significant amounts of 5alpha-DHP are accumulated in pituitary and hypothalamus, but not in uterus, which suggests that its presence may be functionally important in governing progesterone-sensitive processes in these feedback tissues.

20-alpha-Dihydroprogesterone↗
PubMed1973

Movement of the feline esophagus associated with respiration and peristalsis. An evaluation using tantalum markers.

The outer, lateral esophageal walls in the distal half of the esophagus in each of five cats were labeled with small tantalum wires. About 8 wk later, esophageal motion associated with respiration and peristalsis, induced by injecting barium boli (5 ml each) into the proximal esophagus, was recorded on cine and serial biplane roentgenograms while recording intraluminal esophageal pressures simultaneously by manometry. Esophageal motion was also evaluated without a manometric tube in place. The coordinates for each marker were digitized and a computer was used to plot marker position against time. During respiration, the markers passively made a shallow, 2-10 mm excursion on the longitudinal esophageal axis. This movement was synchronous with thoracic and diaphragmatic movement and changes in intraluminal esophageal pressure. Immediately after the onset of peristalsis, the markers made a pronounced oral movement of 10 mm or more above their mean respiratory position, as if to engulf the bolus. Markers in opposing esophageal walls approximated one another and commenced an aboral movement as the bolus tail, which was essentially co-incident with onset of the manometric pressure complex, passed the marker sites. The markers returned to their respective rest positions essentially coincident with passage of the pressure complex peak and then moved below their respective rest positions. The aboral excursion occurred predominantly after the bolus had emptied into the stomach. The magnitude and duration of oral excursion was significantly greater for the distal than for the more proximal markers; conversely, the magnitude and duration of aboral excursion was greater for the proximal than for the more distal markers. During the peristaltic sequence, the labeled portion of the esophagus shortened from 26 to 46% of its resting length. No evidence of esophageal torque was shown. These findings suggest that both the longitudinal and circular esophageal musculature play an active and important role during peristaltic transport of a bolus through the esophagus.

Animals↗
PubMedDate not supplied

Conversion of 17 alpha-hydroxyprogesterone to 5 alpha, 3 alpha, and 20 alpha-reduced metabolites by female rat anterior pituitary and hypothalamus.

The metabolism of 17 alpha-[3H]hydroxyprogesterone was examined in female rat anterior pituitary and hypothalamic tissues. After reverse isotopic dilution analysis and purification to constant specific activity, the following 5 alpha-, 3 alpha- and 20 alpha-reduced products were detected in both tissues: 17 alpha-hydroxy-5 alpha-pregnane-3,20-dione; 3 alpha,17 alpha-dihydroxy-5 alpha-pregnan-20-one; 17 alpha,20 alpha-dihydroxy-4-pregnen-3-one and 5 alpha-pregnane-3 alpha,17 alpha,20 alpha-triol. While the metabolites formed were qualitatively the same, there were quantitative differences between the two tissues. The 3 alpha,5 alpha-reduced metabolite, 3 alpha,17 alpha-dihydroxy-5 alpha-pregnan-20-one, was the principal product in the anterior pituitary while the 5 alpha-reduced metabolite, 17 alpha-hydroxy-5 alpha-pregnane-3,20-dione, was produced in largest amount by the hypothalamus. With both tissues, the aforementioned four products plus starting substrate accounted for nearly all of the starting radioactivity. There was no evidence for the formation of C19 steroids (androgens) despite the presence of the 17 alpha-hydroxy group.

17-alpha-Hydroxyprogesterone↗
PubMedDate not supplied

Detection of multiple papillary fibroelastomas of the tricuspid valve by transesophageal echocardiography.

A 66-year-old man without symptoms, referred for the treatment of moderate hypertension, was found to have a right atrial mass by two-dimensional echocardiography. On transesophageal echocardiography two masses were detected on the tricuspid valve, the first one on the posterior leaflet and the second smaller one on the anterior leaflet. These findings were confirmed at surgery. Histologic analysis revealed that the masses represented papillary fibroelastomas.

Aged↗
PubMedDate not supplied

Magnetic resonance imaging study of the congenital clubfoot treated with the Ponseti method.

Little information exists about the degree of efficacy of the several nonoperative treatments, such as manipulation and casting, used in correcting the pathology of the virgin clubfoot deformity. The steps in the correction of the displacements and anomalies of the skeletal components have never been visualized. The method reported to have the best long-term results is that of Ponseti. A magnetic resonance imaging protocol was devised to image the described chondroosseous abnormalities of the virgin clubfoot deformity and to illustrate the changes that occur with the Ponseti method of treatment. Scans were performed at the beginning of, in the middle of, and at the end of treatment. Images obtained with this protocol largely agree with postmortem studies of clubfeet. All of the major chondroosseous pathology could be visualized in vivo. With Ponseti treatment, all the abnormalities seen on the initial scans either improved markedly or corrected completely. Treatment resulted in correction not only of the abnormal relationships of the tarsal bones, but also of the abnormal shapes of the individual tarsal osteochondral anlages, probably because of the changes in growth resulting from the changes in mechanical loading of fast-growing tissues.

Clubfoot↗
PubMedDate not supplied

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Adult↗