Volunteers as adjunct researchers in a cancer prevention trial: the American Cancer Society Colon Polyp Prevention Study

BACKGROUND

In April 1991, the Virginia Division of the American Cancer Society (ACS) initiated the feasibility phase of the Colon Polyp Prevention Study (CPPS) to determine whether a high fiber supplement would decrease new adenomatous colorectal polyp occurrence. The feasibility phase had two specific objectives: 1) to evaluate accrual and compliance to the designed protocol and 2) to evaluate and demonstrate the effectiveness of volunteers as research assistants. The CPPS is an innovative project in which trained volunteers play a significant role in the research process.

METHODS

In the CPPS, volunteer adjunct researchers (VARs) were trained to perform individual dietary data collection and intervention and other general study monitoring functions. VARs were trained, certified, and monitored in the performance of their assigned tasks by ACS staff and expert consultants.

RESULTS

A total of 119 volunteers were trained as VARs, 74 of whom were certified and matched to a study participant. Between 1991-1995, only six VARs left the study. After active accrual of participants to the study ceased in 1995, 38 VARs (50% of the certified VARs) continued to monitor the active study participants. All VARs were consistently able to conduct the functions for which they were trained.

CONCLUSIONS

In spite of expected volunteer attrition rates, a core of 38 dedicated VARs were matched to 72 participants and demonstrated the ability to perform selected data collecting activities on a consistent and efficient basis. The use of trained volunteers has allowed the CPPS to function in its feasibility phase at personnel cost considerably less than that of other similar cancer prevention trials.

Percutaneous endoscopic gastrojejunostomy: a dual center safety and efficacy trial

Although jejunal tube placement through a percutaneous endoscopic gastrostomy (PEG) has not been proven to be preferable to PEG feeding, it would be theoretically advantageous for those patients prone to gastrointestinal aspiration. However, reliable placement of a small bowel feeding tube through a PEG has been technically difficult. We have previously reported successful placement of a percutaneous endoscopic gastrojejunostomy (PEG/J) with minimal complications. These results are in contrast to other series that report technical difficulty, frequent tube dysfunction and gastric aspiration. We describe an over-the-wire PEG/J technique performed by multiple operators at two medical centers. Gastrostomy tube placement was successful in 94% of patients. Initial placement of the jejunal tube was successful in 88% of patients. Second attempts were 100% successful. The average procedure time was 36 minutes. The distal duodenal and jejunal placement of the jejunal tube resulted in no episodes of gastroduodenal reflux. Complications included jejunal tube migration (6%), clogging (18%), and unintentional removal (11%). The majority of patients were ultimately converted to either oral or intragastric feedings. We conclude that the PEG/J system is a reliable, reproducible method of small bowel feeding and is associated with no episodes of tube feeding reflux when the jejunal tube is positioned in the distal duodenum or beyond. Furthermore, it provides a temporary nutritional bridge for those patients who are later transitioned to either PEG or oral feeding.

Hepatic lidocaine metabolism and liver histology in patients with chronic hepatitis and cirrhosis

Recent advances in the medical and surgical treatment of chronic hepatitis and cirrhosis have made it increasingly important to develop noninvasive tests of liver function. Our study has evaluated the hepatic conversion of lidocaine to its primary metabolite monoethylglycinexylodide and compared this with liver histological findings in 225 patients with chronic hepatitis (161 with hepatitis C, 23 with hepatitis B, 21 with autoimmune hepatitis and 20 with cryptogenic hepatitis). One hundred seven (47.7%) patients had cirrhosis at the time of evaluation. A decline in monoethylglycinexylodide production was observed with worsening liver histological conditions from a mean of 81.5 +/- 7.0 ng/ml in patients with chronic persistent hepatitis to 61.2 +/- 5.5 ng/ml for chronic active hepatitis and 20.9 +/- 1.5 ng/ml in patients with cirrhosis (p < 0.05). A further stepwise decline in monoethylglycine xylodide production was observed with worsening Child class: from 25.5 +/- 2.2 ng/ml for class A patients to 8.9 +/- 1.4 ng/ml for patients with Child class C disease (p < 0.05). All patients with monoethylglycinexylodide production less than 20 ng/ml had cirrhosis confirmed on histological examination. In contrast, no relationship was observed between liver histological status and serum transaminases (AST or ALT), bilirubin, albumin and prothrombin time. Thirty-five patients underwent repeat histological evaluation and monoethylglycinexylodide testing after receiving at least 6 mo treatment for chronic hepatitis (interferon for hepatitis B and C and corticosteroids for autoimmune hepatitis). The change in monoethylglycinexylodide production observed in these patients was a linear function of the change in Knodell histological index (r = 0.73, p < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of hydrophobic bile acids on 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity and mRNA levels in the rat

We have previously reported that relatively hydrophobic bile acids, decreased hepatic 3-hydroxy-3-methylglutaryl-coenzyme A reductase (reductase) activity whereas, hydrophilic bile acids had little effect on the enzyme. The purpose of the present study was to determine in more detail the mechanism of down-regulation of hepatic reductase activity by hydrophobic bile salts. Groups of rats were fed bile acids of differing hydrophobicity: ursodeoxycholic, cholic (CA), chenodeoxycholic (CDCA), deoxycholic (DCA), or cholesterol for 14 days. Reductase specific activities and concentrations of reductase protein were determined in hepatic microsomes. Quantitation of "steady state" levels of reductase mRNA was performed using Northern and dot blot hybridization. Reductase gene transcriptional activity (nuclear "run-on") was determined in nuclei isolated from livers of animals fed different bile acids. Hydrophobic bile acids and cholesterol significantly decreased reductase activity: CA (57%), CDCA (77%), DCA (73%), cholesterol (89%), and reductase protein levels as measured by an enzyme-linked immunosorbent assay method were also decreased; CA (27%), CDCA (31%), DCA (42%), and cholesterol (35%). Reductase mRNA levels were also decreased after feeding hydrophobic bile acid: CA (43%), CDCA (47%), DCA (54%), and cholesterol (53%). Ursodeoxycholic, a hydrophilic bile acid, caused a much smaller decrease in reductase activity (18%), protein mass (16%), and mRNA levels (10%). Decreased transcriptional activities were observed in CA- and cholesterol-fed rats. Surprisingly, CDCA- and DCA-fed animals showed transcriptional activities similar to control animals even though steady state mRNA levels were low in CDCA- and DCA-fed animals. We hypothesize a post-transcriptional regulation of reductase mRNA by hydrophobic bile acids.

Experimental unilateral coronal synostosis in rabbits

Immobilization of the coronal suture was produced unilaterally in 9-day-old rabbits to determine its effect on subsequent craniofacial development. The suture was immobilized unilaterally by the topical application of methylcyanoacrylate adhesive. Subsequent growth effects on the cranial vault, base, and facial skeleton were assessed by serial radiographic cephalometry. Unilateral coronal suture immobilization resulted in significantly decreased bone growth at the coronal suture (mean 0.95 mm +/- 0.35 SE) when compared to sham-treated control animals (mean 5.06 mm +/- 0.20 SE). Frontonasal suture bone growth contralateral to the immobilized half of the coronal suture, however, was significantly increased. The anterior cranial base became significantly shortened, and orbital asymmetry developed. The pattern of induced abnormalities simulates unilateral coronal synostosis in humans.