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Biomedical subjects

R Johnson

Publications and source records attributed to R Johnson.

At least 577 records · Page 32Linked to original sources
PubMed1981

Intestinal fistula and obstruction following pelvic exenteration.

Intestinal fistulas and obstruction are the most common and most serious complication of pelvic exenteration for gynecologic cancer. In a series of 58 patients, early intestinal fistulas developed in seven and late fistulas in 13 of the patients. Early fistulas are more commonly secondary to surgical trauma or technical errors and were noted to occur more frequently in patients who had previously undergone irradiation. Late fistulas are usually associated with intestinal obstruction and with a high incidence of recurrent malignant growth. The management of choice for intestinal fistulas following pelvic exenteration appears to be prompt surgical intervention with bypass procedures in preference to intestinal resections. Although several technical modifications have been applied to the exenterative operation with a trend toward a decrease in early obstruction and fistula formation rate, additional technical efforts will be necessary if these problems are to be solved.

Adult↗
PubMed1981

Internal vomiting in the ruminant: effect of apomorphine on ruminal pH in sheep.

Five sheep, with a rumen fistula inserted, were each injected (IV) with apomorphine (18 mg) and ruminal pH was measured every 5 minutes during a 1-hour period. During the base-line period (30 minutes) that preceded apomorphine injection, pH was constant in individual sheep and te group mean (+/- SD) was 7.1 +/- 0.35. After apomorphine was injected, group mean was 6.9, 6.0, 6.3, 6.3, 6.3, 6.4, 6.4, 6.5, 6.7, 6.9, 6.9, and 7.1 at 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 minutes, respectively. The pH reduction of ruminal content was recorded in 4 of the sheep. Maximal reduction occurred in the 10-minute period after apomorphine was injected. The pH returned to control value within 40 to 50 minutes after injection. Vomitus was not expelled through the mouth by any of the sheep. It was concluded that expulsion of acidic abomasal contents back into the preabomasal compartment (internal vomiting) was the cause of acidification of the rumen after apomorphine was injected.

Animals↗
PubMed1980

Independent lines of evidence suggesting a major gap junctional protein with a molecular weight of 26,000.

Several polypeptides have been described in the past as components of gap junction fractions. Of these, a peptide of Mr 26,000 is found in gap junctions isolated from livers of different species under conditions that minimize proteolysis. Tryptic digestion of purified "intact" junctions causes the rapid disappearance of this peptide with a concomitant appearance of a band of Mr 10,000, which has previously been found to be characteristic of junctional fractions isolated with the aid of proteolytic treatment. Both the peptides of Mr 26,000 and 10,000 are missing from gap junction preparations after partial hepatectomy, when gap junctions are absent from the surface of the hepatocytes. They have reappeared in fractions from the livers of animals killed 3 days postoperatively, when gap junctions are again present in vivo.

Animals↗
PubMed1980

Pathogenetic role of 1 alpha,25-dihydroxyvitamin D in sarcoidosis and absorptive hypercalciuria: different response to prednisolone therapy.

Intestinal hyperabsorption of calcium (Ca) is frequently observed in sarcoidosis and is characteristic of absorptive hypercalciuria (AH). The potential pathogenetic role of 1 alpha,25-dihydroxyvitamin D [1,25(OH)2D] in these two conditions was sought by a careful assessment of the circulating concentration of this vitamin D metabolite and various measures of Ca metabolism before and after prednisolone therapy. In eight patients with sarcoidosis, prednisolone treatment (50 mg/day for 8 days) produced a significant fall in serum 1,25(OH)2D [4.8 +/) 1.9 to 3.3 +/- 1.0 (SD) ng/dl; P less than 0.025], concomitant with a significant decrease in the fracitional intestinal Ca absorption (alpha) from 0.58 +/- to 0.14 to 0.46 +/- 0.13 (+/- SD; P less than 0.005). Urinary Ca and serum parathyroid hormone did not change significantly. However, in six patients with AH, prednisolone therapy resulted in a nonsignificant rise in serum 1,25(OH)2D from 3.6 +/- 0.7 to 4.4 +/- 1.0 ng/dl and no significant fall in alpha (from 0.73 +/- 0.08 to 0.70 +/- 0.10). Urinary Ca was significantly increased in AH patients from 230 +/- 35 to 343 +/- 74 (SD) mg/day (P less than 0.005), while serum parathyroid hormone rose slightly. Serum 1,25(OH)2D and alpha were significantly correlated (r = 0.543; P less than 0.05) for patients with sarcoidosis but not in AH patients. These results suggest that the hyperabsorption of calcium in sarcoidosis is dependent on the serum concentration of 1,25(OH)2D, while in AH it may result from additional vitamin D-independent processes.

Calcitriol↗