Shiro Hosoda

Effects of pectin on fatty acid and glucose absorption and on thickness of unstirred water layer in rat and human intestine.

Effects of pectin, a soluble dietary fiber, on fatty acid and glucose absorption were studied in vivoin rats and humans by perfusing the intestine with linoleic acid and glucose solutions with and without pectin. Linoleic acid and glucose absorption decreased with increasing concentrations of pectin. The reduction in linoleic acid absorption was not caused by binding of linoleic acids by pectin or impaired micelle formation due to binding of bile acid by pectin. The unstirred water layer expanded with increasing concentrations of pectin. These results suggest that enlargement of the unstirred water layer is closely associated with the reduction of absorption of fatty acid and glucose ingested with pectin.

Effect of pectin, a soluble dietary fiber, on functional and morphological parameters of the small intestine in rats.

We investigated the effects of pectin, a soluble dietary fiber, on functional and morphological parameters of the small intestine in rats. A control group and a pectin-fed group were given a fiber-free elemental liquid diet and an elemental liquid diet containing 2.5% (w/w) pectin, respectively, for 2 weeks. The ileal mucosal specific activities of maltase, sucrase and alkaline phosphatase increased significantly in the pectin-fed group. Maltose absorption of the ileum, studied in vitro by the method of everted sacs and disaccharide-dependent potential difference, increased significantly in the pectin-fed group. The length of the small intestine as well as the villus height and crypt depth of both the jejunum and the ileum were significantly greater in the pectin-fed group. The crypt cell production rate of the jejunum and the ileum was also significantly greater in the pectin-fed group. Plasma enteroglucagon, but not gastrin, increased significantly in the pectin-fed group. These data suggest that pectin feeding results in hyperplasia of the small-intestinal mucosa and a significant increase in the enzyme activities of the brush border membrane of the ileum.

Effect of epidermal growth factor by different routes of administration on the small intestinal mucosa of rats fed elemental diet

SummaryThis study was undertaken to investigate the effect of epidermal growth factor (EGF) on the rat small intestinal mucosa by three different routes of administration. Four-week-old rats were fed elemental diet for 4 weeks and were administered EGF either subcutaneously, intraluminally or intraperitoneally with mini-osmotic pumps for a week. Intraperitoneal administration of EGF resulted in a significant increase of mucosal wet weight, mucosal content of protein and DNA, villus height, crypt depth and crypt cell production rate. Intraluminal or subcutaneous administration of EGF tended to increase those morphological and proliferative parameters, but did not cause any significant change. We conclude that EGF caused the hyperplasia of the small intestine of rats maintained on oral elemental diet and that this trophic effect was clearly shown by the intraperitoneal route of administration, rather than by the intraluminal route. These results suggest that EGF receptors located in the basal portion of crypt cells play a more important role than those located in the microvillous membrane.

Clostridium ramosum, an IgA Protease-Producing Species and Its Ecology in the Human Intestinal Tract

A bacterial strain isolated from feces of a patient with ulcerative colitis, which had been shown to produce a novel immunoglobulin A (IgA) protease (cleaving both the human IgA1 subclass and IgA2 subclass of A2m(1) allotype) extracellularly, was identified as Clostridium ramosum. By using a selective medium (proprion‐ate‐rifampicin‐gentamicin‐colimycin‐polymyxin medium) devised for C. ramosum, analysis of the population level of this organism was performed to determine its ecology in the human intestinal tract. C. ramosum was isolated in 20 of 25 fecal samples (80%) from patients with inflammatory bowel disease (I.B.D.) and in 112 of 135 samples (83%) from patients without I.B.D. (control group). C. ramosum was also isolated from 6 of 11 biopsy samples (55%) of the inflamed rectal mucosa from patients with ulcerative colitis and from five of 15 samples (33%) from the intact mucosa of the control group. The population levels of C. ramosum in most of the biopsy samples ranged from 2.3 to 5.0 log10 per gram. The IgA protease‐positive C. ramosum was found in only four of 135 fecal samples (3%) and one of 15 biopsy samples (6.7%) from the control group. These results indicate that IgA protease‐positive C. ramosum is not likely to play a role in the induction of I.B.D., unless the organism is first isolated from the patient with I.B.D.

Early development of serotonin neuron in the rat brain as studied by immunohistochemistry combined with tryptophan administration

Early differentiation of serotonin (5HT) neurons was studied by an immunohistochemical technique in the metencephalon of rat embryos of CR lengths of 6 mm to 22 mm. Pregnant dams were treated with tryptophan (100 mg/kg) and pargyline (100 mg/kg). The synthesis of 5HT after tryptophan loading first occurs at any stage in the premature cells located in the ependymal layer. The cells appearing at the later embryonic stage begin 5HT synthesis at an earlier developmental stage of neurons with greater capacity to produce 5HT. Two different processes were revealed for the development of 5HT neurons. Most of the 5HT neuroblasts first give off axonal processes and then begin to migrate toward the mantle layer with reversed rotation. Some of the 5HT neuroblasts, later generated in the rostral pons in particular, display characteristic transformation without notable migration. After sending out of axonal processes ventrally, the apical processes are transformed into a number of dendritic processes directed toward the ventricular surface.

Serum levels of interleukin-1β and interleukin-6 in patients with chronic pancreatitis

To investigate the role played by cytokines in chronic pancreatitis, we examined serum levels of interleukin-1β (IL-1β) and interleukin-6 (IL-6) by radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) in 33 patients with definitively diagnosed chronic pancreatitis. All the patients, who had received either no treatment or only digestive enzyme products for their chronic pancreatitis, had significantly elevated serum IL-1β levels (38.5±28.8pg/ml, mean ± SD), compared to normal controls (16.0±6.7pg/ml;P<0.01); however they showed no changes in serum IL-6 levels. Changes in IL-1β and IL-6 serum levels were not correlated with the etiological features of pancreatitis or with complications due to liver diseases. Serum IL-1β and IL-6 levels were also not correlated with the activity of any pancreatic enzymes in blood or urine. However, in the patients with chronic pancreatitis, serum IL-6 levels were correlated with C-reactive protein (CRP), whereas serum IL-1β levels were not correlated with CRP or with erythrocyte sedimentation rate. These results suggest that serum IL-1β is involved in the progression and reduction of chronic inflammation of the pancreas, and that the serum IL-1β level may be useful as a marker for chronic pancreastitis.

The trophic effect of epidermal growth factor on morphological changes and polyamine metabolism in the small intestine of rats

SummaryThis study was undertaken to evaluate the effect of epidermal growth factor (EGF) on the morphological changes and polyamine metabolism in the atrophic small intestinal mucosa of rats caused by feeding elemental diet (ED; Elental®, Ajinomoto, Tokyo) for several weeks. Four-week-old Wistar male rats were given ad libitum ED (1 kcal/ml) for 4 weeks. The body weight increased to the same extent as the control group fed a pellet diet. However, the small intestine became atrophic: the mucosal wet weight of the jejunum decreased to 70%, while that of the ileum decreased to 60%. EGF (10 Μg/kg) was subcutaneously injected into these rats every 8 hours. Ornithine decarboxylase (ODC) activities of the jejunal and ileal mucosa rose within 12 hours of the initial EGF administration. Mucosal DNA specific activities tended to increase. Next, EGF (30 Μg/kg/day) was intraperitoneally administered with a Mini-osmotic pump for one week. The wet weight, protein and DNA contents of the ileal mucosa increased significantly compared with those of the saline administered controls, while the crypt cell production rate (CCPR) also increased. Histologically, increases in both villus height and crypt depth were confirmed. These findings indicate that EGF causes mucosal proliferation through polyamine metabolism even in the atrophie small intestine of mature rats after ED administration for 4 weeks.

Effect of intrinsic CCK and CCK antagonist on pancreatic growth and pancreatic enzyme secretion in pancreaticobiliary diversion rats

When pancreaticobiliary diversion (PBD) surgery was performed in rats, plasma CCK level increased, the pancreas grew mainly by proliferation, and pancreatic trypsinogen showed a remarkable increase, although amylase and lipase synthesis were somewhat decreased. The sensitivity of amylase release against CCK-8 in the pancreatic acini decreased when plasma CCK level was high. These changes in pancreatic growth and pancreatic enzyme secretion caused by PBD were completely inhibited by the CCK-receptor antagonist loxiglumide. From these results, intrinsic CCK was considered to play an important role in both pancreatic enzyme synthesis and proliferationWhen pancreaticobiliary diversion (PBD) surgery was performed in rats, plasma CCK level increased, the pancreas grew mainly by proliferation, and pancreatic trypsinogen showed a remarkable increase, although amylase and lipase synthesis were somewhat decreased. The sensitivity of amylase release against CCK-8 in the pancreatic acini decreased when plasma CCK level was high. These changes in pancreatic growth and pancreatic enzyme secretion caused by PBD were completely inhibited by the CCK-receptor antagonist loxiglumide. From these results, intrinsic CCK was considered to play an important role in both pancreatic enzyme synthesis and proliferation

Trisomy 4 in a case of acute lymphocytic leukemia (L1)

Trisomy 4 has been identified previously as a chromosome abnormality associated with acute nonlymphocytic leukemia (ANLL) with myelomonocytic lineage and in myelodysplastic syndromes (MDS). We report a case of acute lymphocytic leukemia (ALL) (French-American-British, FAB L1) in a 42-year-old Japanese man, with trisomy 4 as the sole chromosomal anomaly. Immunophenotypically, the leukemic blasts demonstrated reactivity with CD2, CD5, and CD7 and indicated on early stage of T cell.

Complement Component C3 Production and its Cytokine Regulation by Gastrointestinal Epithelial Cells

In the gastrointestinal tract, several studies have focused on evidence of local complement activation as one of the factors concerned with the pathogenesis of gastrointestinal disorders. Recently, evidence of local complement component C3 production in intestinal tract were demonstrated in vivo by Ahrenstedt et al., 1 but its cellular origin has not been identified. In this study, we examined the possibility of C3 production by intestinal epithelial cells using colonic adenocarcinoma cell lines; Caco-2, HT-29, and HT-29N2 cells. The de novo synthesis and secretion of C3 by all three cells were observed, and its production was up-regulated by certain cytokines such as interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)α.