Treatment of gastrointestinal radiation injury with hyperbaric oxygen.

BACKGROUND: Chronic radiation enteritis develops in 5-20% of patients following abdominal and pelvic radiation. Current treatments are largely ineffective. OBJECTIVE: To assess the effectiveness of hyperbaric oxygen therapy (HBO2) as a treatment for chronic radiation enteritis and evaluate the relative effectiveness in treatment of the proximal and distal gastrointestinal tract. DESIGN: Case series of 65 consecutive patients with chronic radiation enteritis treated between July 1991 and June 2003 with HBO2. SETTING: A tertiary referral academic medical center. PATIENTS: 65 patients (37 male, 28 female; mean age 65 years) were treated with HBO2 for radiation damage to the alimentary tract. INTERVENTIONS: Patients were treated with an initial series of 30 daily treatments, each administering 90 minutes of 100% oxygen at 2.36 atmospheres absolute pressure. Thirty-two patients with partial symptom response or endoscopic evidence of healing received an additional 6 to 30 treatments. RESULTS: The primary indication for HBO2 was bleeding (n = 54) with 16 patients requiring transfusions. Additional indications were pain, diarrhea, weight loss, fistulas and obstruction. Follow-up ranged from 1 to 60 months (mean = 23 months). The main outcome measures were effects on bleeding, pain, diarrhea, weight loss, fistulas and obstruction. Endoscopic documentation of healing was used when available. The response rate was 68%, with a complete and partial response rate of 43 and 25%, respectively. The response rate for rectal disease was 65% and for proximal sites was 73%. The response rate for bleeding was 70% and for other symptoms was 58%. CONCLUSION: This series represents the largest clinical series reported using HBO2 for treatment of radiation injury to the GI tract. The findings suggest that HBO2 results in healing or clinically significant improvement in two thirds of patients with chronic radiation enteritis.

Multidisciplinary approach to pseudoaneurysms complicating pancreatic pseudocysts. Impact of pretreatment diagnosis.

OBJECTIVE: To determine the effectiveness of thin-section, dynamic-contrast computed tomography and angiography in detecting the presence of pancreatic pseudoaneurysms. DESIGN: This case series consisted of 57 patients who were being examined for endoscopic drainage of pancreatic pseudocysts. SETTING: All patients were examined in a tertiary care, teaching hospital. PATIENTS: Fifty-seven consecutive patients were examined for 2 years. Follow-up ranged from 6 months to 2 years. INTERVENTIONS: All patients underwent thin-section, high-speed, dynamic-contrast computed tomography. Those patients with findings that were consistent with the presence of a pseudoaneurysm underwent angiography. Embolization was attempted if a pseudoaneurysm was present. Endoscopic retrograde cholangiopancreatography was used to determine pancreatic ductal anatomy before operation. MAIN OUTCOME MEASURE: No undetected pseudoaneurysm has complicated this series of endoscopically drained pseudocysts. RESULTS: Five patients had findings that were consistent with a pancreatic pseudoaneurysm on computed tomography. Angiographic findings confirmed a pseudoaneurysm in four patients, and angiographic embolization was successful in three. Four patients underwent resection, while one was treated with embolization and endoscopic stenting of a compressed pancreatic duct. There were no mortalities. CONCLUSIONS: Before endoscopic drainage of a pancreatic pseudocyst, a thin-section, high-speed, dynamic-contrast computed tomographic scan is essential. If there are findings consistent with the development of a pseudoaneurysm, angiography must be performed. This allows delineation of the arterial anatomy, as well as the option of performing angiographic embolization. While patients with pseudoaneurysms in the body and tail of the pancreas underwent resection, angiographic embolization alone was an acceptable alternative when the lesion was located in the head of the pancreas.

Acute gastric dilatation revisited.

First described by S.E. Duplay in 1833, acute gastric dilatation has since been well documented in the literature. Several theories of the pathogenesis of acute gastric dilatation have been postulated. In 1842, Karl Freiherr von Rokitansky described the superior mesenteric artery syndrome, followed by W. Brinton in 1859 with the atonic theory. C.R. Morris et al. introduced debilitation and anesthesia as predisposing factors. Although rare, gastric necrosis is the most severe consequence of acute gastric dilatation. Vascular insufficiency secondary to increased intragastric pressure is the critical factor. We report an unusual case of acute gastric dilatation with subsequent necrosis of uncertain etiology.

The dermatitis-producing constituents of Euphorbia hermentiana latex.

Five ingenane derivatives, 3-O-n-(deca-2,4,6-trienoyl)-16-O-[(Z)-2-methyl-2-butenoyl]-16-hydroxyingenol (1), 3-O-[(Z)-2-methyl-2-butenoyl]-5,16,20-O-triacetyl-16-hydroxyingenol (2), 3-O-[(Z)-2-methyl-2-butenoyl]-16,20-O-diacetyl-16-hydroxyingenol (3), 3-O-[(Z)-2-methyl-2-butenoyl]-20-O-acetylingenol (4), and 3-O-[(Z)-2-methyl-2-butenoyl]-16-O-acetyl-20-deoxy-16-hydroxyingenol (5) were isolated with a new procedure that uses droplet counter-current chromatography, from a dermatitis-producing fraction of the latex of Euphorbia hermentiana Lem. The structures of the new compounds 2,3, and 5 were established by the interpretation of their spectroscopic data and those of their hydrolytic and acetylated derivatives.

RNase PH: an Escherichia coli phosphate-dependent nuclease distinct from polynucleotide phosphorylase.

Final trimming of the 3' terminus of tRNA precursors in Escherichia coli is thought to proceed by an exonucleolytic mechanism. However, mutant strains lacking as many as four exoribonucleases known to act on tRNA still grow normally and process tRNA normally. Extracts from such a multiple-RNase-deficient strain accurately mature tRNA precursors exonucleolytically in vitro in a reaction that requires inorganic phosphate. Here we show that this reaction is not due to polynucleotide phosphorylase (PNPase) but, rather, that it is mediated by a phosphate-requiring exonuclease that we have named RNase PH. Purified PNPase is incapable of completely processing tRNA precursors, and extracts from a PNPase- strain retain full activity for phosphorolytic processing. Although both PNPase and RNase PH act in a phosphorolytic manner, they differ substantially in size and substrate specificity. RNase PH has a molecular mass of 45-50 kDa and favors tRNA precursors as substrates. The possible physiological role of RNase PH and the advantages of phosphorolytic processing are discussed.

Effects of diterpene esters of tigliane, daphnane, ingenane, and lathyrane types on pink bollworm,Pectinophora gossypiella saunders (Lepidoptera: Gelechiidae).

Twenty esters, representing the biogenetically related tigliane, daphnane, ingenane, and lathyrane series of diterpenes, were screened for growth-inhibitory and insecticidal effects on newly hatched larvae of the North American cotton pest,Pectinophora gossypiella (pink bollworm). Among the tigliane derivatives tested, only 12-O-tetradecanoylphorbol-13-acetate and 12-O-(2-methyl)butyrylphorbol-13-decanoate, of seven phorbol diesters isolated from croton oil by a new procedure involving droplet countercurrent chromatography, were active againstP.gossypiella as both growth inhibitors and insecticides. The effects of the former compound were not significantly diminished by acetylation of its C-20 primary hydroxy group. Three other croton oil phorbol diester constituents, as well as daphnetoxin and daphnetoxin-5,20-diacetate, exhibited activity as growth inhibitors, but not as insecticidal agents, at the doses used. None of the ingenane or lathyrane derivatives investigated was active in either respect. 12-0-Tetradecanoylphorbol-13-acetate was found to cause 100% mortality on second-stadium larvae ofCulex pipiens at 0.6 ppm, but exhibited less significant effects onOncopeltus fasciatus (second-stadium nymphs) andTribolium confusion (adults) when applied at higher doses.