Biopharmaceutics: Enhanced Absorption of Calcium after Oral Administration of Maltitol in the Rat Intestine

The enhancing effects of maltitol (α-D-glucopyranosyl-1,4-sorbitol) on absorption of calcium by the rat intestine have been studied by use of [⁴⁵Ca]CaCl₂ in-vivo. After intragastric administration of [⁴⁵Ca]CaCl₂ solution with maltitol, plasma ⁴⁵Ca concentration remained at the maximum level for more than 80 min, whereas for animals given [⁴⁵Ca]CaCl₂ solution without maltitol, plasma ⁴⁵Ca concentration declined sharply after the peak. Determination of ⁴⁵Ca radioactivity remaining in the various segments of the gastrointestinal tract revealed that administration of maltitol elicited slower gastric emptying and slower intestinal transit, resulting in extensive ⁴⁵Ca distribution along the small intestine throughout the experimental period. The luminal contents of the small intestine were significantly higher in rats given maltitol than in the control group. These results suggest that the enhancing action of maltitol on intestinal calcium absorption could be attributed to reduced gastrointestinal calcium transit and increased luminal fluid content, presumably because of the osmotic activity of maltitol; this would not only accelerate the dissolution of calcium into the increased luminal contents, but also enable a larger area of the small intestine to absorb calcium for a longer period of time.     

Concentration gradient of oxalate from cortex to papilla in rat kidney

BACKGROUND: The kidney eliminates the major fraction of plasma oxalate. It is well known that oxalate is freely filtered by glomeruli and secreted by the proximal tubules. However, the renal handling of oxalate in distal nephrons, which is considered as playing an important role in stone formation, remains obscure. METHODS: At 15-180 min after intravenous injection of 14C-oxalate to rats, the intrarenal localization of radioactivity was quantitatively measured by the radioluminographic method using a bioimaging analyzer. Tissue radioactivity was compared with plasma, and urinary radioactivities were measured by a liquid scintillation counter. The control study was conducted with 14C-inulin. RESULTS: The radioactivity of 14C-oxalate in the papilla was 10 times greater than in the cortex and eight times greater than in the medulla 180 min after injection when almost no radioactivity was present in the urine. In contrast, the radioactivity of 14C-inulin was nine times less in the papilla than in the cortex at the same time. CONCLUSION: Oxalate remains in the renal papilla for an extended period. This accumulation of oxalate may be attributed to calcium oxalate crystal fixation along the deep nephron which is considered to be the first step of stone formation.     

New in vitro method for detecting asthma allergen

Changes in the morphology and number of basophils were examined after the addition in vitro of house dust extract in cells from seventy-seven patients with bronchial asthma. Morphological changes (reactive basophils) showed a close relation to the end-point titrations of antigen in skin tests, RAST score and bronchial provocation tests, but changes in number of basophils did not. With a RAST score of 2 or greater the change in reactive basophils varied from 40 to 80% (mean 58-1%), which was much greater than seen in persons with no RAST, score 0. Patients with positive bronchial inhalation tests, showed 40 to 80% (mean 57.8%) reactive basophils, whereas persons with a negative bronchial challenge test showed a range of reactive basophils from 0 to 50% (mean 28.9%). The difference in percentage of reactive basophils between the positive and negative groups of persons tested by bronchial inhalation was statistically significant.     

Power Doppler imaging of hepatic tumours: Differential diagnosis between hepatocellular carcinoma and metastatic adenocarcinoma

We evaluated the usefulness of power Doppler imaging in the differential diagnosis between hepatocellular carcinoma and metastatic adenocarcinoma. Forty-seven patients with hepatocellular carcinoma and 18 patients with metastatic adenocarcinoma were evaluated using power Doppler imaging. The colour signals of hepatic tumours were graded as follows: 1, colour signals only in the marginal area; 2, small dot or dotted line colour signals within the tumours; 3, continuous solid line colour signals within the tumours. The grade 3 colour signals were classified in the following three patterns; winding line pattern, stretched line pattern and mixed pattern. The colour signals of hepatocellular carcinoma were grade 1 in seven patients, grade 2 in 11 and grade 3 in 29. The colour signals of metastatic adenocarcinoma were grade 1 in three patients and grade 3 in 15. Of the 29 hepatocellular carcinoma patients with a grade 3 signal, 26 patients had winding line patterns and three had mixed patterns. Of the 15 metastatic adenocarcinoma patients with a grade 3 signal, 12 patients had stretched line patterns and three had mixed patterns. In conclusion, power Doppler imaging is useful in the differential diagnosis between hepatocellular carcinoma and metastatic adenocarcinoma to evaluate the colour signal pattern within the tumour.     

Progress report on phase I/II clinical trial of Ad-OC-TK plus VAL therapy for metastatic or locally recurrent prostate cancer: Initial experience at Kobe University

There is no effective therapy for hormone-refractory prostate cancer and a novel therapeutic modality, such as a gene therapy, should be actively pursued. Previously, Gardner and Chung conducted a phase I clinical trial of Ad-OC-TK (recombinant adenoviral vector containing osteocalcin promoter-driven herpes simplex virus thymidine kinase gene) plus VAL (valacyclovir) for the treatment of hormone-refractory prostate cancer at the University of Virginia. We report on our ongoing phase I/II clinical trial of Ad-OC-TK plus VAL for the treatment of advanced prostate cancer at the Kobe University Hospital, Japan.     

Cut-to-the-light technique and potassium titanyl phosphate laser ureterotomy for complete ureteral obstruction

We describe a case of complete ureteral obstruction managed by endoscopic recanalization using a 'cut-to-the-light' technique followed by potassium titanyl phosphate (KTP) laser ureterotomy. A 53-year-old man developed a ureteral obstruction following the transurethral resection of a bladder tumor (TUR-Bt) at the left ureteral orifice. The length of the obstructed segment was estimated at 1 cm based on combined antegrade and retrograde contrast studies. Histopathological analysis indicated that the obstruction was caused by fibrosis. The 'cut-to-the-light' technique was used for recanalization, and KTP laser ureterotomy was performed to obtain an adequate ureteral lumen. A 14 F/7 F endoureterotomy stent was removed 6 weeks after the operation. No significant complications and no signs of stenosis were observed 24 months after endoscopic repair. Endoscopic recanalization is a safe, effective technique for the management of a completely obliterated ureteral segment, especially in combination with subsequent KTP laser ureterotomy.     

Decrease in reactivity of basophils by immunotherapy with housedust extract

Changes of basophil reactivity to housedust extract and anti-IgE during immunotherapy was examined in thirteen patients with bronchial asthma sensitive to housedust. (i) A significant decrease in the morphological reactivity of basophils to housedust extract was observed 6 months after the beginning of immunotherapy with the antigen, and a significant decrease after 12 and 18 months’ therapy, accompanied with the decrease of histamine release from the cells. The percent reactive basophils to the antigen decreased from 59.2 ± 2.9% before the therapy to 40.0 ± 1.8% after 18 months’immunotherapy. (ii) A decrease in the morphological reactivity of basophils to anti-IgE was also shown during immunotherapy. The basophil reactivity to anti-IgE decreased significantly at the late stage (18 months) of immunotherapy. (iii) A significant reduction of specific IgE antibody to housedust was observed 12 and 18 months after the beginning of immunotherapy. It was suggested from these results that immunotherapy causes some changes on the surface of basophils and decreased reactivity of the cells, and that a decrease of reactive basophils to anti-IgE in the process of immunotherapy might be due to a decrease in number of IgE receptors essentially or functionally.