Jacques Rautureau

Assessment of net postprandial protein utilization of 15N-labelled milk nitrogen in human subjects.

The nutritional quality of milk proteins, evaluated both in terms of digestibility and postprandial oxidation and retention in human subjects, was investigated in this study. Five healthy adult volunteers were given 480 ml 15N-labelled milk (i.e. 190 mmol N). 15N was subsequently determined at the ileal level, using a naso-intestinal intubation technique, as well as at the faecal level. Plasma and urine were sampled for 8 h after meal ingestion. Dietary exogenous N recovered at the terminal ileum after 8 h reached 8.6 (SE 0.8) mmol while the amount collected in the faeces was 6.5 (SE 0.7) mmol after 5 d. The true ileal and faecal digestibilities were 95.5 (SE 0.4)% and 96.6 (SE 0.4)% respectively. The appearance of [15N]amino acids in the plasma was rapid and prolonged. The measurement of 15N in the body urea pool and in the N excreted in the urine allowed us to calculate the deamination occurring after [15N]milk protein absorption. The net postprandial protein utilization (i.e. NPPU = (Nabsorbed-Ndeaminated)/Ningested), calculated as an index of protein quality 8 h after milk ingestion, was 81.0 (SE 1.9)%. Our data confirm that milk protein has a high oro-ileal digestibility in man and demonstrate that milk protein has a high NPPU, an index corresponding to a period in which the dietary protein retention is maximal.

Absence of Human Papillomavirus DNA Detected by Polymerase Chain Reaction in French Patients With Esophageal Carcinoma

BACKGROUND & AIMS Recent studies have suggested that esophageal human papillomavirus infection could be a risk factor for esophageal squamous cell carcinoma. The aim of this study was to evaluate the prevalence of human papillomavirus DNA sequences in the esophagus of French patients with esophageal squamous cell carcinoma. METHODS Multiplex polymerase chain reactions with consensus primers directed to the L1 gene or specific primers for human papillomavirus types 6, 11, 16, 18, 31, and 33 directed to E6 gene (40 cycles followed by restriction mapping of the amplified products) were used to determine the presence of human papillomavirus DNA sequences in esophageal squamous cell carcinoma (n = 75), normal adjacent mucosa (n = 49), and metastatic lymphadenopathies (n = 5). As an internal control, a target located in the embryonic myosin heavy-chain gene was used in each reaction. RESULTS Human papillomavirus DNA sequences could not be detected in any of the tumoral samples, the normal adjacent mucosa, or the metastatic lymphadenopathies. CONCLUSIONS Human papillomavirus seems not to be implicated in esophageal carcinogenesis, at least in French patients, because the viral genomes are not associated with esophageal squamous cell carcinomas.

The gastro-ileal digestion of 15N-labelled pea nitrogen in adult humans.

The aim of the present study was to determine the gastro-ileal behaviour of pea protein in humans. For this purpose, twelve healthy volunteers were intubated with an intestinal tube located either in the jejunum (n 5) or in the ileum (n 7). After fasting overnight, they ingested 195 mmol N of [15N]pea. Intestinal samples were collected for 6 h in the jejunum and for 8 h in the ileum. Before meal ingestion the basal liquid flow rate (ml/min) was 2.01 (SD 0.31) in the jejunum and 2.02 (SD 0.33) in the ileum. After meal ingestion the liquid phase of the meal peaked in the 40-60 min period in the jejunum and in the 150-180 min period in the ileum. The jejuno-ileal transit time of the liquid phase of the meal was 102 min. The basal flow rate of endogenous N (mmol N/min) was 0.22 (SD 0.15) in the jejunum and 0.16 (SD 0.10) in the ileum. The endogenous N flow rate peaked significantly (P < 0.05) in the jejunum in the 40-60 min period whereas no stimulation of endogenous N could be detected in the ileum after meal ingestion. A significantly increased (P < 0.05) concentration of exogenous N was detected in the jejunum during the 20-320 min period and during the 90-480 min period in the ileum. The overall true gastro-ileal absorption of pea N was 89.4 (SD 1.1)% with 69 (SD 14)% absorbed between the stomach and the proximal jejunum and 20.4% between the proximal jejunum and the terminal ileum. The percentage of ethanol-insoluble fraction (PN) in the exogenous N at the terminal ileum increased significantly (P < 0.05) to 75% after 360 min. These results suggest that heat-treated pea protein has a digestibility close to that of animal protein.

Role of salivary and seric epidermal growth factor in pathogenesis of reflux esophagitis in chronic alcoholics and nondrinkers

Our objective was to investigate the putative role of epidermal growth factor (EGF) in esophagitis pathogenesis in both nondrinkers and chronic alcoholics. We studied the EGF serum level, the EGF salivary concentration, and the esophageal EGF receptor expression in different groups of patients with esophagitis: nondrinkers with typical symptoms of gastroesophageal reflux (N=12) and chronic alcoholics (N=12), and in controls: chronic alcoholics without esophagitis (N=16) and healthy nondrinkers (N=12). All patients had an endoscopy with esophageal biopsies, 24-hr esophageal pH-metry, and esophageal manometry. EGF serum levels and EGF salivary concentrations were determined by radioimmunoassay. EGF receptor expression was determined by immunohistochemistry. Both the EGF serum level and the EGF salivary concentration remained constant, 328±21 pg/ml and 305±48 pg/ml, respectively, regardless of alcohol intake and the presence or absence of esophagitis. In addition, the presence of esophagitis did not affect the EGF receptor expression. These results suggest that seric and salivary EGF is not involved in the pathogenesis of reflux esophagitis in nondrinkers and in chronic alcoholics.

Comparison of two sucralfate dosages presented in tablet form in duodenal ulcer healing

Two hundred twenty-two patients with endoscopically proven duodenal ulcers participated in a controlled trial to assess and compare the effects of two dosage regimens of sucralfate tablets on ulcer healing, i.e., 1 g four times daily (group A, n = 131) and 2 g twice daily (group B, n = 128). Healing was defined as complete re-epithelialization. Clinical and endoscopic assessments were performed after four weeks (Day 28) and, if complete healing was not achieved, after four more weeks (Day 56). After four weeks, in group A (n = 114: eight patients were lost and nine were withdrawn), the ulcers had healed in 90 patients (79 percent), and in group B (n = 108: six patients were lost and 14 were withdrawn), the ulcers had healed in 80 patients (74 percent). The cumulative healing rates after eight weeks were 94 percent in group A and 95 percent in group B. No serious adverse effect was observed in either group. These results suggest that sucralfate tablets in a dosage of 2 g twice daily are as effective as 1 g four times daily in the treatment of acute duodenal ulcers and could lead to better patient compliance.

Effects of a high soy protein diet on intestinal polyamines and ornithine decarboxylase activity in rats.

This study was performed to determine whether intestinal luminal polyamine concentrations are affected by a high soy protein diet when compared with a high casein diet or a normoprotein casein diet. We also determined the effects of these diets, with differences in polyamines content, on mucosal polyamines and ornithine decarboxylase (ODC) activity to assess cell proliferation. Three groups of eight male Wistar rats were fed either a 50% soy protein diet, a 50% casein diet, or an 18% casein diet as a control. After 4 weeks of feeding, both intestinal content and mucosa were recovered. Polyamines were assayed by high performance liquid chromatography. ODC activity was measured by the release of (14)CO(2) from (14)C-L-ornithine. Luminal putrescine and cadaverine concentrations were higher in the jejunum than in the ileum, suggesting an absorptive process. The highest concentrations of intestinal polyamines were observed in rats fed the soy protein diet (P < 0.05). Only minor differences were observed in mucosal polyamines according to the diets. ODC activity was also higher in the intestinal mucosa of rats fed the high soy protein diet (P < 0.05). These results suggest that intestinal luminal polyamine concentrations and ODC activity are modulated by the dietary protein source.