Basic studies on ursodeoxycholyl-para-aminobenzoic acid for evaluation of intestinal microflora

Diagnosis by Microbial Culture, Breath Tests and Urinary Excretion Tests, and Treatments of Small Intestinal Bacterial Overgrowth

Small intestinal bacterial overgrowth (SIBO) is characterized as the increase in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract and accompanies various bowel symptoms such as abdominal pain, bloating, gases, diarrhea, and so on. Clinically, SIBO is diagnosed by microbial culture in duodenum/jejunum fluid aspirates and/or the breath tests (BT) of hydrogen/methane gases after ingestion of carbohydrates such as glucose. The cultural analysis of aspirates is regarded as the golden standard for the diagnosis of SIBO; however, this is invasive and is not without risk to the patients. BT is an inexpensive and safe diagnostic test but lacks diagnostic sensitivity and specificity depending on the disease states of patients. Additionally, the urinary excretion tests are used for the SIBO diagnosis using chemically synthesized bile acid conjugates such as cholic acid (CA) conjugated with para-aminobenzoic acid (PABA-CA), ursodeoxycholic acid (UDCA) conjugated with PABA (PABA-UDCA) or conjugated with 5-aminosalicylic acid (5-ASA-UDCA). These conjugates are split by bacterial bile acid (cholylglycine) hydrolase. In the tests, the time courses of the urinary excretion rates of PABA or 5-ASA, including their metabolites, are determined as the measure of hydrolytic activity of intestinal bacteria. Although the number of clinical trials with this urinary excretion tests is small, results demonstrated the usefulness of bile acid conjugates as SIBO diagnostic substrates. PABA-UDCA disulfate, a single-pass type unabsorbable compound without the hydrolysis of conjugates, was likely to offer a simple and rapid method for the evaluation of SIBO without the use of radioisotopes or expensive special apparatus. Treatments of SIBO with antibiotics, probiotics, therapeutic diets, herbal medicines, and/or fecal microbiota transplantation are also reviewed.

[Surgical treatment of cancer at the beginning of the third millenium--based on the 2004 Krompecher Memorial Lecture of the Society of Hungarian Oncologists]

The author presents a historical overview of cancer surgery of the last century. At the last quarter of the century the main characteristic of this process has been the significant extension of surgical radicality. Three new surgical methods appeared and have been routinely used at the Surgical Clinic of the Szeged University School, to increase surgical radicality, to improve survival rate without impairing the postoperative quality of life. 1.) Subtotal colectomy (STC) involves an extended resection of the colon over the splenic flexure. In a period of 8 years a total of 72 STCs were performed for the treatment of large bowel obstructions or symptomatic stenosis caused by cancer of the left colon. STC offers: a) one stage treatment for colonic obstruction in emergency surgery, b.) removal of the tumor with sufficient oncological radicality, c.) primary reconstruction of the digestive tract, with a safe ileocolic anastomosis even in emergency cases. Based on a study about postoperative quality of life of STC operated patients, it proved to be normal. 2.) The author reports a total of 108 middle and low third rectal cancer cases operated on by total mesorectal excision (TME) by the method of Heald. The oncological basis of this procedure is the horizontal regional metastatization of rectal cancer. The author succeeded in 60% of cases to perform an anterior resection with preservation of the anal sphincter, and to decrease the early (within two years after surgery) local recurrence rate from 14.5% to 6.4%, compared to the group of patients operated on by traditional technic. 3.) A total of 154 patients with locally advanced - stage IV - colorectal cancer underwent extended surgery of multivisceral resections as a treatment of cancer process involving adjacent abdominal organs. Surgery was performed to treat advanced cancer of the colon in 112 cases and the one of the rectum in 42 cases. The mortality rate was 7% in the colon cancer group, and 12% in the group of rectal cancer patients. In their tumor-free postoperative period 90% of colon cancer patients and 95% of rectal cancer patients had an improved quality of life. The 5 years survival rate was 40% in the colon group and 22% in the rectal cancer group. In the group of patients having more than 3 simultaneously tumorous organs, in spite of the multiple organ resections, no 5 years survival has been recorded.

The role of mouse intestinal microflora in the metabolism of trichloroethylene, an in vivo study

1. Both trichloroethylene and its metabolite, dichloroacetic acid, produce liver tumors peroxisome proliferation and other adverse cellular alterations in rodents. 2. The hepatic mechanism by which dichloroacetic acid is formed is not conclusively demonstrated, but pharmacokinetic models have successfully associated its formation with trichloroacetic acid as immediate precursor. 3. Previous investigations have shown that dichloroacetic acid is formed from trichloroacetic acid by gut microflora isolated in vitro. 4. To determine the impact of gut microflora on dichloroacetic acid formation from a trichloroethylene dose in vivo, we developed a procedure which reduced gut microflora some 3 orders of magnitude below published levels. 5. The administration of trichloroethylene to control mice and to mice whose gut was practically sterile resulted in equivalent concentrations of dichloroacetic acid and other metabolites in blood and liver, but significantly different content of these metabolites in cecum contents. 6. These data indicate that gut microflora contribute minimally, if at all, to the formation of circulating dichloroacetic acid under these conditions.

Use of the conjugate of disulphated ursodeoxycholic acid with p-aminobenzoic acid for the detection of intestinal bacteria

The disulphate ester of ursodeoxycholyl-p-aminobenzoic acid (PABA-UCDA) was synthesised and compared with PABA-UDCA for its use in detection of intestinal bacteria. This compound, PABA-UDCA disulphate, had characters in common with PABA-UDCA in that it was deconjugated by cholylglycine hydrolase to release free PABA and bacteria that split glycocholic acid deconjugated PABA-UDCA disulphate. Further, in rat experiments urinary excretions of PABA were measured for six hours after oral administration of 15 mg PABA-UDCA disulphate. Ten control rats excreted (mean (SE) 188.2 (13.6) micrograms of PABA; 10 rats with an intestinal stagnant loop excreted more (530.1 (30.1) micrograms; p < 0.001): whereas 10 rats in each of three groups pretreated by oral administration of various antibiotics excreted less (polymixin B+tinidazole, 4.9 (1.6) micrograms; kanamycin, 31.0 (4.7) micrograms; clindamycin 40.9 (5.5) micrograms; p < 0.001). By contrast with PABA-UDCA, PABA-UDCA disulphate was not actively absorbed from any part of the small intestine in everted gut sac experiments, and showed poor recovery from bile after its intraileal instillation in rats. This indicated that PABA-UDCA disulphate is a single pass type substance in the gut and its oral administration test reflects the sum of the activities of bacteria in the small intestine and colon. The disulphate was easily soluble in water and this allowed its application in an in vitro test involving PABA-UDCA disulphate incubation with intraperitoneal pus (PABA-UDCA disulphate incubation test) from patients with peritonitis. This test was carried out on six patients with peritonitis, and the severity of bacterial peritonitis was expressed quantitatively. From the results obtained PABA-UDCA disulphate was considered a good material to detect intestinal bacteria.