Effect of maternal ethanol consumption during pregnancy and lactation on kinetic parameters of folic acid intestinal transport in suckling rats.

Ethanol ingestion is known to interfere with folate absorption and metabolism. A fostering/crossfostering analysis of maternal ethanol exposure effects on jejunum and ileum kinetic parameters in vivo of offspring rat folic acid absorption at 21 days postpartum was carried out. The rats were divided into four groups: CP, control pups; GP, pups exposed to ethanol only during gestation; LP, pups exposed to ethanol only during lactation; GLP, pups exposed to ethanol during gestation and lactation. Jejunal and ileal loop transport studies were performed using in vivo perfusion at a flow rate of 3 ml/min for 5 min. Folic acid concentrations of 0.25, 0.5, 1, 1.5 and 2.5 microM: were used. Jejunal and ileal absorption values were determined by the difference between the initial and the final amounts of substrate in the perfusate and expressed as picomoles per square centimeter of intestinal surface every 5 min. The results indicated that ethanol consumption by the dams during gestation and/or lactation led to significant changes in V(max), with no significant changes in apparent K(m). These findings suggest that exposure to ethanol during gestational and suckling periods leads to a general delay in postnatal body weight and that intestinal folate absorption appears to be upregulated in suckling rats, this effect being higher in the LP group.

[A study of antibiotic use at a county hospital. Years 1998-2002]. / Estudio de la utilización de antibióticos de un hospital comarcal. Años 1998-2002.

INTRODUCTION: Adequate antibiotic use clearly influences the development of bacterial resistance, adverse events and healthcare costs. Studies of drug usage allow us to detect deviations in antibiotic use. MATERIAL AND METHODS: Antibiotic use during the period 1998-2002 was analyzed using data provided by management software applications. The prescription of restricted-use antibiotics during years 2001 and 2002 was analyzed by selecting patients according to the information available in the unit-dose drug distribution area database at the pharmacy department. RESULTS: Antibiotic use increased from 78 to 100 DDD during the period of time studied. The use of new quinolones has displaced macrolides. Two thirds of piperacillin --tazobactam prescriptions are for surgical patients. CONCLUSIONS: 1. Changes in the pattern of antibiotic use have been detected. 2. The relative weight of restricted-use antibiotics has increased. 3. This study allows a prioritization of intervention areas.

In vivo sugar diffusion in the ileal epithelium of spontaneously hypertensive rats.

BACKGROUND: D-glucose absorption, distinguishing between active and diffusive components, was studied in the ileum of spontaneously hypertensive rats (SHR) and their normotensive control Wistar-Kyoto (WKY) rats. Net water transport was also determined. METHODS: A perfusion system in vivo with ileum loops was used, and experiments with phlorizin, phloretin and 2,4,6-triaminopyrimidine (TAP) were performed in order to discriminate between active and diffusive components and between transcellular and paracellular routes. RESULTS: A significant decrease in total D-glucose absorption was found in SHR compared to WKY rats, this reduction being due to a lower SGLT1-mediated component. The effect was not compensated by the total diffusive component, since the phlorizin-insensitive D-glucose absorption did not significantly change between rat strains. However, the diffusive component of D-glucose transport was relatively more important in hypertensive than in normotensive rats. The use of 2,4,6-triaminopyrimidine (TAP), which blocks the transport across the paracellular route, showed that the paracellular diffusion of D-glucose was higher in SHR than in WKY rats. Intestinal net water absorption was not modified between either group of animals, though the presence of phlorizin in the perfusate decreased the ileal water absorption to a greater extent in normotensive rats. CONCLUSION: The observed reduction in D-glucose absorption in vivo in the ileum of SHR was due to a decrease in the SGLT1-active component. Despite the paracellular diffusion of D-glucose being higher in hypertensive than in normotensive rats, the total diffusion component was not high enough to compensate this alteration.

Laparoscopic colorectal cancer resection: initial follow-up results.

An observational prospective cohort study was made to evaluate the results of laparoscopic colorectal cancer resection, in terms of recurrence and patient survival. Fifty consecutive patients were analyzed, subjected to abdominoperineal amputations of the rectum (n = 10), anterior rectal resection (n = 13), rectosigmoidectomy (n = 18), and other colectomies (right, left, segmentary) (n = 9). Mean follow-up was 21 months (maximum, 42 months). The tumors corresponded to stage I (TNM classification of the International Union Against Cancer) in 6 cases, stage II in 17, stage III in 18, and stage IV in 9 cases. Survival in stages I-IV was 100, 92, 79, and 18%, respectively, with a disease-free survival rate of 100, 70, and 49% in stages I-III, respectively. Recurrence was pelvic in four cases, with multiple growths, peritoneal carcinomatosis, lung metastases, and implantation in the port scar in one case each. To conclude, survival after a maximum follow-up period of 42 months was found to be acceptable and similar to the percentages reported in the literature for open surgery.

alpha-MeGlc and D-glucose transport by hepatopancreatic brush border membrane vesicles from prawn.

Sugar transport by prawn (Penaeus japonicus) hepatopancreatic epithelium has been studied. Brush-border membrane vesicles (hBBMV) were isolated, studies of osmotic reactivity were made indicating that these vesicles were closed and with low contamination from basolateral membranes. Incubation of hBBMV in the presence of Na+ resulted in rapid sugar uptake by the vesicles with an overshoot at 5 min, achieving the equilibrium value at 60 min. The absence of Na+ or the presence of phloridzin inhibited the overshoot. This uptake appears to be dependent on the membrane potential, since K+ efflux down its concentration gradient in the presence of valinomycin accelerated sugar influx and increased the overshoot when K+-loaded hBBMV were used. The kinetic study of Na+-dependent sugar uptake reveals that values of Km and Vmax were of the same order of magnitud as those described for other absorptive epithelia.

Folate transport by prawn hepatopancreas brush-border membrane vesicles.

The transport system of folic acid (Pte-Glu) by brush-border membrane vesicles (BBMV) isolated from prawn (Penaeus japonicus) hepatopancreas, was studied by measuring the uptake of Pte-Glu. This uptake was found to have two components, intravesicular transport and membrane binding. Membrane binding was not affected by the presence of a transmembrane pH-gradient at a short incubation period. However, a transmembrane pH-gradient increased membrane binding at 60 min. The transport of Pte-Glu appeared to be carrier-mediated, was stimulated by an inwardly proton gradient (pH 5.5 outside, 7.4 inside) and was unaffected by a sodium-gradient. The relationship between pH gradient-driven Pte-Glu uptake and medium Pte-Glu concentration followed saturating Michaelis-Menten kinetics. Eadie-Hofstee representation of the pH gradient-driven Pte-Glu uptake indicated a single transport system with a Km of 0.37 microM and Vmax of 1.06 pmol/mg protein/15 s. These findings indicate that BBMV isolated from prawn hepatopancreas possesses a Pte-Glu transport system similar to that described in mammalian intestine.

Taurocholate transport by brush border membrane vesicles from different regions of chicken intestine.

Taurocholate transport was studied in brush border membrane vesicles (BBMV) isolated from chicken small (duodenum, jejunum, and ileum) and large (proximal cecum and rectum) intestines, using a rapid filtration technique. The purity of the BBMV was verified by the finding that the specific activity of sucrase (a brush border membrane enzyme marker) was severalfold greater in vesicles than corresponding values in mucosal homogenate. The functional integrity of isolated BBMV was evaluated by the uptake of D-glucose, which showed a transient increase in the presence of Na+. A Na+-dependence of taurocholate uptake was shown in BBMV prepared from ileum, cecum, and rectum, as taurocholate transport was transiently increased (accumulation) in the presence of a Na+ gradient between the external medium and intravesicular medium. The magnitude of the accumulation was similar among ileum, cecum, and rectum. In contrast, BBMV prepared from duodenum and jejunum did not show any Na+-dependent taurocholate transport, as the taurocholate uptake was not affected when a Na+ gradient was replaced by a K+ gradient. The use of taurochenodeoxycholate in the incubation medium inhibited Na+-dependent taurocholate transport in the ileum, cecum, and rectum. This study is the first to show the presence of a Na+-dependent bile salt transport in BBMV obtained from chicken ileum, proximal cecum, and rectum.

Laparoscopic treatment of esophageal achalasia.

An observational cohort study evaluated the initial results of using laparoscopic-approach cardioesophageal myotomy with Dor-type anterior fundoplicature for esophageal achalasia. The study involved our first 12 patients: five men and seven women whose median age was 51 years. Esophageal motility was vigorous in four patients; the other eight had aperistalsis. Conversion to laparotomy was required in one case. No postoperative mortality occurred. Postoperative complications included one left subdiaphragmatic abscess secondary to perforation of the esophageal mucosa, which was sutured. Median postoperative hospital stay was 5 days (confidence interval, 4.7-6.7 days). Symptom relief (disappearance of dysphagia) was recorded in 10 cases; relief with partial persistence of dysphagia was observed in the remaining two patients, who were treated by postoperative dilatation. As to the postoperative manometric results, the median basal pressure of the lower esophageal sphincter was reduced from 26.3 mm Hg preoperatively to 15.5 mm Hg postoperatively, with a tendency toward statistical significance (p = 0.08); the median esophageal isotopic retention after 15 min decreased from 60% preoperatively to 24.5% after surgery, with a tendency toward statistical significance (p = 0.07). Cardiomyotomy with Dor fundoplicature through a laparoscopic approach seems effective in treating esophageal achalasia.

Injury in laparoscopic surgery.

A prospective study was made to evaluate injury caused by laparoscopic surgery, in terms of physiological response. Two groups of patients were established: Group 1 (laparoscopic surgery, n = 26) and Group 2 (open surgery, n = 18). The groups were homogeneous in terms of age, sex, body mass index (BMI), duration of surgery, and anesthetic technique. Both groups exhibited significant postoperative increases in plasma adrenocorticotropic hormone (ACTH), growth hormone (GH), insulin, and cortisol (p < 0.05), with a significant decrease in follicle-stimulating hormone (FSH) and T3 (p < 0.05). Significant increases were noted in 24-h urine cortisol and catecholamine levels in Group 2 (p < 0.05). No correlation was noted between the duration of surgery and the intensity of neuroendocrine response. Acute-phase postoperative metabolic response was greater in Group 2 and was correlated to the duration of surgery. No postoperative hydrosaline or acid-base alterations were recorded in either group. Injury was graded in terms of neuroendocrine and metabolic response and proved highest in Group 2. Complex laparoscopic surgery (e.g., sigmoid colon and esophageal hiatus) exhibited the least neuroendocrine response, whereas laparoscopic inguinal hernioplasty involved the least metabolic response. To conclude, laparoscopic surgery globally involves less neuroendocrine and metabolic response than does open surgery.

Phospholipid fatty acid composition of hepatopancreatic brush-border membrane vesicles from the prawn Penaeus japonicus.

Brush-border membrane vesicles (BBMV) were isolated from prawn hepatopancreas as we previously described (Muriana et al (1993) J Biochem 113, 625-629). The characterization of hepatopancreatic BBMV (hBBMV) by monitoring the activity of marker enzymes indicated a relatively pure apical membrane preparation reduced in basolateral contamination. Phospholipid composition of hBBMV was examined by the Iatroscan TLC/FID technique, whereas the fatty acid profile of phospholipids was examined by capillary gas chromatography. Phosphatidylcholine and phosphatidylethanolamine are the principal phospholipids of these membranes. The major fatty acids of phospholipids are palmitic (16:0), palmitoleic (16:1n-7), stearic (18:0), oleic (18:1n-9), eicosapentaenoic (20:5n-3) and docosapentaenoic (22:5n-3) acids. Individual phospholipids are characterized by distinct fatty acid compositions, but display a similar ratio of unsaturated-to-saturated fatty acids and a similar unsaturation index.

Phospholipid fatty acid compositions of hepatopancreas and muscle from the prawn, Penaeus japonicus.

The hepatopancreas and muscle of the prawn, Penaeus japonicus, were analyzed as to the phospholipid fatty acid composition. The most important lipids in the hepatopancreas are triglycerides and phospholipids, while the lipids in muscle are principally phospholipids and free cholesterol. Fatty acids such as palmitic (16:0), stearic (18:0), oleic (18:1 n-9), eicosapentaenoic (20:5 n-3), and docosahexaenoic (22:6 n-3) were prominent in the total phospholipid fatty acid composition. However, phosphatidylethanolamine appeared to be particularly rich in n-3 polyunsaturated fatty acids, sphingomyelin in saturated fatty acids (mainly 18:0), and phosphatidylinositol in monounsaturated fatty acids (mainly 18:1 n-9). Our data indicated that each phospholipid class is characterized by a specific paraffin chain composition.

Lipid and fatty acid composition of hepatopancreatic brush-border membrane vesicles from the prawn Penaeus japonicus.

Brush-border membrane vesicles (BBMV) were isolated from prawn hepatopancreas by a procedure involving Mg2+ preparation. The lipid composition of hepatopancreatic BBMV (hBBMV) was examined by the Iatroscan TLC/FID technique, and the fatty acid profile of total lipids was determined by capillary gas chromatography. hBBMV were characterized by a high content of phospholipids and cholesterol. However, the cholesterol/phospholipid molar ratio is lower in prawn than in vertebrate BBMV, which agrees well with the membrane fluidity of BBMV from different sources. The fatty acid composition of hBBMV was similar to that in marine crustacean oils. The major fatty acids present were palmitic (16:0), palmitoleic (16:1n-7), stearic (18:0), oleic (18:1n-9), and eicosapentaenoic (20:5n-3) acids. The large amount of long-chain polyunsaturated fatty acids seems to be related to a high delta 5-desaturase activity in hBBMV.

Influence of external K+ on potassium efflux in isolated chicken enterocytes.

1. Efflux of K+ was measured in pre-loaded (86Rb+) chicken enterocytes incubated in buffers with external K+ concentration ([K+]0) between 1 and 40 mM. 2. A decrease in [K+]0 from 6 to 1 mM reduced the rate constant of K+ efflux, whereas it was stimulated by increasing [K+]0 from 6 to 40 mM. 3. The inhibitory effect of low [K+]0 on K+ efflux was: (i) higher than that expected from a change in the electrical driving force, suggesting that membrane K+ permeability has been decreased, and (ii) attenuated by A23187 and Na(+)-free buffers. 4. The effect of A23187 on K(+)-induced K+ efflux was abolished by apamin and that of Na(+)-free buffers by apamin, quinine or verapamil, which suggests that the effect of low K+ on K+ efflux seems to be due to decreased intracellular Ca2+ concentration. 5. The stimulatory effect of 40 mM K0+ on K+ exit can be accounted for by an increase in the electrical driving force. 6. The efflux of K+ at 40 mM K0 appears to occur through Ca2(+)-activated K+ channels (KCa) since it was prevented by 500 microM quinine and unaffected by bumetanide or 3,4-diaminopyridine. 7. In addition, the current results show that an increase in external K+ concentration reduced the ability of quinine to inhibit KCa channels, and even abolished that of Ba2+ and apamin.

Glycyl-L-sarcosine transport by ATP-depleted isolated enterocytes from chicks.

Normally energized and ATP-depleted isolated chicken enterocytes have been used to investigate the energetics of intestinal glycyl-L-sarcosine (Gly-Sar) transport, and the results were compared with those obtained for 3-O-methyl-D-glucose (3-OMG) active transport, which is known to be energized by the electrochemical Na+ gradient. The results show that even though Gly-Sar had no effect on Na+ efflux from labeled (22Na) enterocytes, 20 mM L-leucine and 20 mM 3-OMG increased the rate constant of Na+ efflux by 34 and 76%, respectively. In ATP-depleted cells 3-OMG was accumulated in response to experimentally imposed inward Na+ gradients; however, Gly-Sar was not accumulated. In the absence of Na+, an inward proton gradient slightly increased Gly-Sar uptake, although no transient accumulation was observed. An increase in membrane potential by replacement of Cl- by NO3- or by imposition of an outward K+ gradient in the presence of valinomycin stimulated both 3-OMG and Gly-Sar uptake, even in the absence of either H+ or Na+ gradient. When in addition to a K+ diffusion potential, a Na+ gradient was present, 3-OMG transient accumulation was further increased (approximately 2-fold over equilibrium value), and Gly-Sar uptake showed the same pattern as that observed when only membrane potential was present. However, in the presence of an outward K+ diffusion potential and an inward H+ gradient Gly-Sar was stimulated approximately threefold, clearly showing a significant overshoot, whereas 3-OMG was not transiently accumulated.

Caecal and colonic uptake of both linoleic acid and cholesterol in rats following intestinal resection.

Caecal and colonic uptake of both linoleic acid and cholesterol were studied in rats after distal small bowel resection (DSBR). The results showed that the surgical operation increased the caecal and colonic uptake of linoleic acid. Supplementation with linolenic acid inhibited caecal and colonic uptake of linoleic acid. Experiments carried out in the presence of rotenone and ouabain suggest that facilitated diffusion is the predominant mechanism of caecal and colonic linoleic acid absorption, at least at low concentrations. An increase in caecal and colonic uptake of cholesterol was observed after the surgical operation. The study showed that facilitated diffusion seems to be the mechanism of linoleic acid absorption in the caecum and colon, and that both organ growth and changes in transport function of the epithelial cells of caecum and colon appear to be involved in the adaptive response of the bowel to intestinal resection.

Changes in uptake of linoleic acid and cholesterol by jejunal sacs of rats in vitro, after distal small-bowel resection.

Both linoleic acid and cholesterol uptake were studied in small-intestinal sacs of rats in vitro after distal small-bowel resection (DSBR). The relationship between linoleic acid concentration and its absorption was non-linear at low concentrations and became linear at high concentrations in the three groups of animals. These observations indicate that a concentration-dependent dual mechanism of transport is operative in linoleic acid intestinal uptake. Experiments with rotenone and ouabain suggest that a facilitated diffusion is the predominant mechanism of absorption at low concentrations, whereas at high concentrations simple diffusion is predominant. The apparent kinetic constants of linoleic acid uptake (Kd, Kt, and Vmax) increased after DSBR. The uptake of linoleic acid is, however, influenced by the simultaneous presence of linolenic acid, the inhibition constant being decreased after the surgical operation. After the surgical operation an increase of cholesterol uptake was observed, with a parallel enhancement in the apparent mass-transfer coefficient (Kd). Taken together, these results suggest that both organ growth and changes in transport function of the enterocytes appear to be involved in the adaptive response of the bowel to intestinal resection.

Glycylsarcosine transport by epithelial cells isolated from chicken proximal cecum and rectum.

The transport of glycylsarcosine (Gly-Sar) has been investigated in cells isolated from the proximal cecum and rectum of the chick, and their characteristics have been compared with those of the jejunal dipeptide transport system. Results show that 1) cecal and rectal cells are capable of actively accumulating Gly-Sar. 2) Gly-Sar initial uptake and steady-state accumulation in cecal and rectal cells were decreased in Na(+)-free mannitol-substituted medium. However, in both cell types, as in jejunal cells, intracellular accumulations higher than one can be observed in the absence of Na+. 3) By lowering the medium pH from 7.4 to 6.0, the Gly-Sar accumulation was stimulated in both cecal and rectal cells. 4) Addition of 1 mM amiloride inhibited Gly-Sar uptake by the cecal and rectal cells. We conclude that proximal cecum and rectum have a dipeptide transport system with properties similar to those found in the jejunum.

Effect of K+ channel-blockers on sugar uptake by isolated chicken enterocytes.

The effects of Ba2+, quinine, verapamil, and Ca2(+)-free saline solutions on sugar active transport have been investigated in isolated chicken enterocytes. Ba2+, quinine, and verapamil, which have been shown to inhibit Ca2(+)-activated K+ channels, decreased basal and theophylline-dependent 3-O-methylglucose (3-O-MG) accumulation. Ca2(+)-free conditions reduced 3-O-MG uptake in theophylline-treated enterocytes, but it had no effect in control cells. On the other hand, the uptake of a non-actively transported sugar, 2-deoxyglucose (2-DOG), by control or theophylline-treated cells was not modified by the presence of verapamil or by Ca2(+)-removal. 3-O-MG increased ouabain-sensitive Na(+)-efflux, but had no effect on either K+ efflux or K+ uptake. However, in the presence of Ba2+, K+ uptake was stimulated by 3-O-MG, and this increase was prevented by ouabain. All these findings are discussed in terms of the role that K+ permeability may play in cellular homeostasis during sugar active transport.

Kinetics of glycylsarcosine transport by isolated chicken intestinal epithelial cells.

Kinetics of Glycylsarcosine (Gly-Sar) uptake by isolated chicken enterocytes was studied by measuring its intracellular concentration, and by discriminating between the saturable and the diffusive components of the total uptake. The diffusive component was greater at pH 6.0 than at pH 7.4, and the J max was also increased by lowering external pH, whereas the Km remained in the same order of magnitude. Carnosine competitively inhibits Gly-Sar uptake, indicating that both share a common transport system.