[Comparison of two treatment models in type-II diabetic patients with poor metabolic control: Preformed combination of glibenclamide 2,5 mg + metformin 400 mg or mono-therapy with sulfonylurea at maximal doses? An evaluation at six months]

Both glibenclamide and metformin have been used alone or in association for many years. In the treatment of type 2 or non-insulin-dependent diabetes (NIDDM). Glibenclamide stimulates insulin release by pancreatic beta cells (pancreatic attachment point), while metformin acts at a peripheral level by increasing glucose absorption in muscular, fatty and hepatic tissues, thus considerably reducing insulin resistance (extra-pancreatic attachment point). The aim of this study was to evaluate the therapeutic efficacy of the pre-formed association of glibenclamide 2.5 mg+metformin 400 mg (treatment group 1) compared to treatment with glibenclamide 5 mg alone (treatment group 2) at almost double therapeutic doses compared to those contained in the association. A total of 40 NIDDM patients were examined (24 females and 16 males) with a mean age of 55.86 years, a mean duration of disease of 9.37 years, generally obese or overweight. From the final results of the study it was found that the associative therapy of glibenclamide 2.5 mg+metformin 400 mg was very advantageous, leading to a significant improvement in the glycometabolic control (HbA1c and fasting plasma glucose) compared to patients treated using single drug therapy who maintained almost stable control of the disease.

Interleukin 10 reduces lethality and hepatic injury induced by lipopolysaccharide in galactosamine-sensitized mice

BACKGROUND & AIMS

Tumor necrosis factor alpha (TNF-alpha) release plays a pivotal role in the pathogenesis of liver injury induced by lipopolysaccharide (LPS) administration in D-galactosamine (GalN)-sensitized mice. Interleukin (IL) 10 is an anti-inflammatory cytokine that inhibits TNF-alpha synthesis and release both in vitro and in vivo and prevents lethality from experimental endotoxemia. The present study was designed to ascertain whether in vivo treatment with IL-10 protects mice against LPS/GalN-induced liver injury.

METHODS

Mice were treated with an intraperitoneal dose of LPS/GalN with or without IL-10 pretreatment. Liver injury was assessed biochemically and histologically, and plasma TNF-alpha levels, liver myeloperoxidase activity, and adhesion molecule expression were determined.

RESULTS

Administration of LPS in GalN-sensitized mice caused lethal shock and massive hepatic necrosis in almost 100% of the mice. The effect was associated with a significant increase in plasma TNF-alpha concentrations, liver myeloperoxidase activity, and up-regulation of adhesion molecules on liver specimens and circulating neutrophils. Pretreatment with IL-10 reduced plasma TNF-alpha concentrations and LPS/GalN-induced liver injury and lethality. Moreover, IL-10 reduced the LPS/GalN-induced liver neutrophil margination and up-regulation of adhesion molecules both on liver specimens and circulating neutrophils.

CONCLUSIONS

The present results suggest that IL-10 therapy could be useful in the treatment of TNF-alpha-mediated liver diseases.

Expression and modulation of C5a receptor (CD88) on skin dendritic cells. Chemotactic effect of C5a on skin migratory dendritic cells

Although it is known that dendritic cells (DC) migrate in response to inflammatory stimuli. There is little information about the expression of receptors for chemotactic factors on DC. The present study has demonstrated by double immunostaining and flow cytometry of Langerhan's cell (LC)-enriched epidermal cell suspensions that a small subpopulation (5-6%) of epidermal resident DC (rLC) expresses receptors for C5a (C5aR). Epidermal rLC positive for C5aR show a round-shape morphology, were located next to the basement membrane and express HLA-DR molecules higher than C5aR negative rLC. These observations suggest that rLC would express C5aR as part of their process of maturation during tissue trafficking. To investigate whether epidermal LC up-regulate C5aR along their differentiation pathway. LC were differentiated in vitro after culture in epidermal cell suspensions supplemented with granulocyte macrophage colony-stimulating factor (GM-CSF). As a result, in vitro differentiated LC increased the expression of C5aR up to 69% of the DC population. In accordance with this observation, interdigitating DC of secondary lymphoid organs (lymph node and tonsil) also expressed (5aR. Migratory CD1a positive DC that spontaneously migrated out of dermal or split-skin organ explants were also positive for C5aR and were used for chemotaxis and chemokinesis assays in response to human recombinant C5a (rC5a). Optimum migration to rC5a was observed at 10(-8)M with a sigmoidal dose response curve. Checkboard analysis demonstrated that locomotion in response to rC5a was chemotaxis and not chemokinesis.

Selective endoscopic retrograde cholangiography and preoperative bile duct stone removal in patients scheduled for laparoscopic cholecystectomy: a prospective study

OBJECTIVES

Laparoscopic cholecystectomy (LC) has become the treatment of choice for patients with symptomatic cholelithiasis. About 10% of patients with symptomatic gallstones may bear associated common bile duct (CBD) stones. The preferred approach to these patients is the removal of CBD stones by endoscopic retrograde cholangiography (ERCP) before LC. However, ERCP before LC should be performed only in patients with suspected choledocholithiasis. The aims of this study were to: 1) generate an efficacious predictive model for selecting patients with suspected choledocholithiasis to submit to preoperative ERCP, and 2) test the safety of the endoscopic/laparoscopic procedure.

METHODS

Historical, biochemical, and ultrasonographic data were collected prospectively. Receiver operating characteristics curve analysis was adopted for determining optimal biochemical and ultrasonographic cut-off values. Multivariate analysis using logistic regression with generation of the best model identifying independent predictors of CBD stones was also employed.

RESULTS

The optimal model predicted a 95% probability of CBD stones in a patient who presented with elevated ALP (over 300 IU/L) and ALT (over 40 IU/L) levels and CBD dilation > 8 mm at ultrasonography. Endoscopic removal of CBD stones was achieved in 95% of patients, with minimal morbidity and no mortality.

CONCLUSIONS

The identified independent predictors of CBD stones are highly efficient selectors of patients with choledocholithiasis. Moreover, endoscopic removal of CBD stones before LC is a safe and efficacious procedure.

[Efficacy and tolerability of paroxetine in the treatment of the depressive phase of bipolar disorders]

Eighty patients aged between 20-65 years and suffering from bipolar disease according to DSM IV criteria, were treated with paroxetine for os at the single dosage of 20-40 mg/die. At regular intervals psychometric reagents were administered for the evaluation and the variations in the bipolar disease. Tolerability was excellent and side-effects mild, with a tendency to regress after the second week of therapy. The clinical assessment and the psychometric findings both suggest that paroxetina has a useful action on the bipolar disease.

Effect of ursodeoxycholic acid on hypertransaminasaemia and bile acid composition in patients undergoing bone marrow transplantation--a double-blind randomized control study

A double-blind randomized placebo controlled trial of ursodeoxycholic acid was performed in 31 patients undergoing T-cell depleted allogeneic or autologous bone marrow transplantation to determine the effectiveness of this hydrophilic bile acid in improving the increase in serum liver enzymes that generally accompanies this procedure. Neither group showed any significant difference in magnitude of the increases in serum transaminases and gamma-glutamyltranspeptidase following the conditioning regimen that included chemotherapy and total body irradiation. In the 6 months after transplantation, serum enzymes decreased in both groups, but were consistently higher in the placebo treated patients, indicating that ursodeoxycholic enhances normalization of liver. Faecal bile acid showed that following chemotherapy and irradiation in which intestinal bacteria are ablated, secondary bile acid formation was practically abolished and faeces contained mainly cholic and chenodeoxycholic acids. During bile acid treatment, ursodeoxycholic acid accounted for 31.3 +/- 10.9% of faecal bile acids compared with 4.0 +/- 2.1% in the basal period. Serum and urinary ursodeoxycholic acid concentrations (mean +/- SD, 13.3 +/- 6.9 mumol/L and 2.65 +/- 0.84 mumol/L, respectively) were significantly higher in patients receiving bile acid than in thos on placebo (mean +/- SD, 0.15 +/- 0.12 mumol/L and 0.29 +/- 0.35 mumol/L, respectively) thus confirming compliance.

Characterization and function of the receptor for IGF-I in human preosteoclastic cells

Using a coculture system, we have recently demonstrated that insulin-like growth factor I (IGF-I) is a mediator of preosteoclastic cell migration toward bone-derived endothelial cells. To better characterize the mechanisms of IGF-I action on preosteoclastic cells we evaluated the expression of type I IGFs receptor in the human leukemic cell line, FLG 29.1, which differentiates toward the osteoclastic phenotype following phorbol ester (TPA) treatment. Scatchard analysis of 125I-labeled IGF-I to FLG 29.1 cells revealed the presence of a single high affinity binding site in both untreated and TPA-treated cells with a similar Kd value (0.3 +/- 0.2 nmol/L and 0.4 +/- 0.1 nmol/L, respectively). In untreated cells, IGF-I binding capacity (1.43 +/- 0.41 fmol/10(6) cells) was significantly (p < 0.05) lower than in TPA-treated cells (2.62 +/- 0.87 fmol/10(6) cells). Competition analyses and crosslinking studies revealed the presence of type I IGF receptor both in untreated and TPA-treated cells. Northern analysis demonstrated that mRNA for IGF-I receptor was expressed by both untreated and TPA-treated FLG 29.1 cells. In addition, FLG 29.1 cells released in the conditioned medium IGFBP-2 and IGFBP-4, whose expression was increased by TPA treatment as demonstrated by ligand and immunoblot analyses. The previous observations of chemotactic action of IGF-I on FLG 29.1 cells was confirmed by ultrastructural observations. Indeed, these cells revealed a marked migratory activity in response to nanomolar concentrations of IGF-I. In addition, the IGF-I receptor alpha IR-3 antiserum inhibited the IGF-I-induced FLG 29.1 cell's migratory activity. These findings clearly show that type IIGF receptor is expressed by osteoclast precursors and that IGF-I induces migration of these through the binding to type I IGF receptors. Binding proteins expressed by osteoclast precursors may play an autocrine role in modulating the IGF-I bioeffects.

Flow cytometric analysis of cytokine receptors on human Langerhans' cells. Changes observed after short-term culture

It is well established that granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-1 and tumour necrosis factor-alpha (TNF-alpha) are involved in Langerhans' cell (LC) development and dendritic cell traffic. However, little is known about the pattern of cytokine receptors on human LC and their modulation during different stages of maturation. The expression of cytokine receptors was studied by flow cytometry on both freshly isolated LC (fLC) and 72-hr cultured LC (cLC). Epidermal cell suspensions enriched in LC were obtained after skin trypsinization and Ficoll-Hypaque gradient. LC were identified by their CD1a positivity. Although the majority of fLC were positive for the alpha chain of GM-CSF receptor (GM-CSFR), the beta chain of GM-CSFR was detected only on 15% of CD1a+ cells. fLC were also positive for IL-1 receptor (IL-1R) type 1, IL-1R type 2, 75,000 molecular weight TNF receptor (TNFR) and interferon-gamma receptor (IFN-gamma R). IL-6R and its transducing signal gp130 were present in a subset of fLC. Granulocyte colony-stimulating factor receptor (G-CSFR), macrophage colony-stimulating factor receptor (M-CSFR), the alpha and beta chain of IL-2R, IL-4R, IL-7R, IL-8R and 55,000 molecular weight TNFR were not detected on fLC. After culture, LC up-regulated the expression of both the alpha and beta chains of GM-CSFR, IL-1R type 2, alpha and beta chains of IL-2R, IL-6R and gp130. In contrast, IL-1R type 1 and 75,000 molecular weight TNFR were down-modulated and the expression of IFN-gamma R was not affected by culture. These results suggest that LC undergo changes in the cytokine receptor repertory during in vitro maturation.

Isolated guinea pig gastric chief cells express tumour necrosis factor receptors coupled with the sphingomyelin pathway

The tumour necrosis factor alpha (TNF), has been implicated in the pathogenesis of non-steroidal anti-inflammatory drug (NSAID) induced gastropathy and Helicobacter pylori induced gastritis. Both conditions are characterised by high plasma pepsinogen concentrations, which are thought to reflect an increased rate of enzyme release by the pepsinogen secreting (chief) cells. The mechanisms responsible for this cell dysfunction are unknown. This study investigates whether chief cells express TNF receptors and, if so, whether their activation results in cell death. Immunohistochemical studies conducted with monoclonal antibodies (mAbs) directed against two TNF receptor associated proteins of 55 kDa (TNF-R1) and 75 kDa (TNF-R2) showed that TNF binding sites were expressed in approximately 100% gastric chief cells. Western blot analysis of whole chief cell lysates probed with the TNF-R1 and TNF-R2 mAbs gave two distinct bands of 55 and 75 kDa in the immunoprecipitate. Incubating chief cells with TNF caused concentration and time dependent cell death, which was prevented by pretreating the cells with anti-TNF receptor mAbs. Exposing the cells to TNF reduced sphingomyelin content by 25%. Sphingomyelinase (10(-6) to 10(-2) IU/ml) mimicked the effect of TNF in that it provoked a concentration and time dependent reduction in chief cell viability and increased pepsinogen release. In conclusion, gastric chief cells express two TNF receptors partially linked to the sphingomyelin pathway. TNF induced chief cell dysfunction might be responsible for the high plasma pepsinogen concentrations seen in patients with NSAID gastropathy or H pylori induced gastritis.

Flatus-related colorectal and anal motor events

Although complaints of excessive "gas" symptoms are frequently encountered in clinical practice, the physiologic and pathophysiologic grounds of flatus events are poorly understood, partly because of the social taboos associated with the topic and partly because of technical difficulties in measuring flatus. For these reasons, we studied the colorectal and anal motor events occurring during artificially evoked flatus events and compared them to those that occurred spontaneously. Five healthy male volunteers were studied by multilumen probes placed in the left colon and rectum and across the anal canal, to observe the flatus-related motor events that occurred after instillation of air into the colon. Flatus-related spontaneously occurring motor events were also checked in 24-hr motility tracings obtained in three patients with functional bowel disorders. Analysis of the tracings showed that both artificially induced and spontaneously occurring flatus-related motor phenomena were characterized by colonic propagated contractions associated with a rise in rectal pressure and early relaxation of the anal sphincter, in a sequence resembling that observed following swallowing. Spontaneous flatus events were associated with colonic waves of lesser amplitude than those following insufflation of air into the colon.

Oesophageal motility in adult coeliac disease

Coeliac sprue is a relatively frequent disease with protean clinical manifestations. Recent studies suggest that gastrointestinal motor abnormalities may explain some symptoms complained of by such patients. We investigated whether coeliac patients have oesophageal motor abnormalities from both a clinical and a physiological point of view. Thirty-six consecutive adult sprue subjects (14 during the florid phase and 22 on gluten-free diet) were studied. A clinical questionnaire on gastrointestinal symptoms (with emphasis on those of oesophageal origin) was administered. Moreover, 18 patients (13 on free and five on gluten-free diet) gave their consent for oesophageal manometry and eight subjects for pH-metry also. Oesophageal clinical symptoms were compared with those of 144 age- and sex-matched controls from a general population sample, and manometry with that of 34 healthy volunteers. Of coeliac patients 50% complained of dysphagia (P < 0.001 vs. controls) and 14% noncardiac chest pain (P = NS vs. controls). Manometric examination showed motor abnormalities in 67% of the subjects examined, consisting of nutcracker oesophagus, hypotonic lower oesophageal sphincter associated with simultaneous contractions, and frequent repetitive (> 3 peaks) contractions. These abnormalities were equally distributed among free and gluten-free diet patients. pH-metry showed only one pathological reflux out of eight subjects studied. We conclude that patients with coeliac sprue may display abnormal oesophageal motility. This confirms previous studies suggesting that gastrointestinal motor abnormalities should probably be added to the clinical spectrum of the disease.

Gastric emptying of solids in patients with nonobstructive Crohn's disease is sometimes delayed

To date, only a few studies of gastric emptying in Crohn's disease have been published in the literature. This might be clinically important because slow-release drug formulations are increasingly available for treatment. Studies in children with gastric involvement suggest that gastric emptying may be delayed in this condition. We studied the scintigraphic gastric emptying of 21 adult patients with nonobstructive Crohn's disease and without gastric or duodenal involvement by the disease, compared with that of 20 healthy volunteers. Overall, no significant differences were found, but subgroup analysis showed that symptomatic patients [half-time (t1/2) 133 +/- 75.9] and those with colonic involvement (t1/2 127.2 +/- 64) had a significantly (p < 0.01) delayed gastric emptying over controls (t1/2 85.5 +/- 15.4). Such a difference was also observed between symptomatic and asymptomatic patients (p < 0.05). We conclude that gastric emptying is slowed in symptomatic patients with nonobstructive Crohn's disease and in those with colonic involvement. This may have therapeutic implications.

Upper gastrointestinal motor abnormalities in children with active celiac disease

Although from the clinical point of view a GI motor disorder can be suspected in celiac disease, objective evidence for this is still lacking. We therefore conducted a study on children with active celiac disease to detect possible GI motor abnormalities in this disease. Fourteen children (age range, 1-13 years) were studied; they underwent fasting and fed manometric recordings in the gastroduodenojejunal area. Four patients were restudied after a 6-month gluten-free diet. Data were compared with those obtained in eight control children. As compared with controls, celiac disease patients showed a shorter duration of activity fronts (p < 0.01) and a significant (p < 0.01) reduction of the postprandial antral motility index; furthermore, > 90% of the patients displayed marked fasting and/or fed motor abnormalities, suggesting a neuropathic disorder. Interestingly, gut dysmotilities disappeared in the four subjects reassessed after the gluten-free diet. It is concluded that celiac disease frequently affects the motor behavior of the gut and that its effects may be reversed by appropriate diet.

Severity scores in respiratory intensive care: APACHE II predicted mortality better than SAPS II

BACKGROUND

In recent years several scoring systems have been developed to describe the severity of illness, to establish the individual prognosis, and to group adult ICU patients by predicted risk of mortality. In addition, these scores can be used to measure and/or compare the quality of care in different ICUs. We compared the mortality predictions of the Acute Physiology and Chronic Health Evaluation (APACHE II) score and a new Simplified Acute Physiology Score (SAPS II) in patients with respiratory disease who require intensive care.

PATIENTS & METHODS

We prospectively studied all 306 admissions from January 1, 1992 through December 31, 1994. McNemar and Hosmer-Lemeshow tests, and receiver operating characteristic (ROC) curves were used to describe and analyze our data.

RESULTS

The average APACHE II score was 17.5 (SD 6.0), corresponding to a mean predicted death rate of 24.9% (SD 17.2%) as compared to an observed overall RICU mortality rate of 21.6%. The average SAPS II score was 39.1 (SD 11.1) corresponding to a mean predicted death rate of 26.0% (SD 18.4%). The ratio between the actual and predicted hospital mortality was 86% for APACHE II and 83% for SAPS II. Survivors had a significantly lower predicted risk of death than nonsurvivors (p < 0.0001) with both indices, and a higher Glasgow coma scale score (p < 0.0001). The ROC-curve analysis suggested the superior predictive ability of APACHE II in our patients. Area under the APACHE II ROC curve was 80.88% (standard error [SE] 2.89%), significantly larger (p < 0.01) than that found for SAPS II (73.52%, SE 3.61%).

CONCLUSIONS

The APACHE II score was a good predictor of hospital outcome and better than SAPS II in our population.

Nitric oxide modulates pepsinogen secretion induced by calcium-mediated agonist in guinea pig gastric chief cells

BACKGROUND & AIMS

Nitric oxide, a putative cellular messenger synthesized from L-arginine, is a powerful modulator of gastric motility and secretions. The aim of this study was to investigate whether (1) guinea pig gastric chief cells express NO synthase, (2) NO modulates the pepsinogen secretion and guanosine 3',5'-cyclic monophosphate (cGMP) generation induced by calcium (Ca2+)-mediated agents, and (3) NO donors and cGMP analogues stimulate pepsinogen release.

METHODS

Chief cells were prepared by sequential digestion with collagenase and Ca2+ chelation. NO generation was measured by determining the NO coproduct citrulline.

RESULTS

NO synthase immunoreactivities were constitutively expressed in approximately 70% chief cells. Carbachol (10 mumol/L) caused a 4- 6-fold increase in pepsinogen release, citrulline generation, intracellular Ca2+ concentration ([Ca2+]i) and cGMP concentration. These effects were concentration dependently inhibited by NG-monomethyl-L-arginine (L-NMMA). As gastrin, cholecystokinin, thapsigargin, and Ca2+ ionophore increased NO generation, [Ca2+]i seemed to regulate NO synthase activity. [Ca2+]i chelator and calmodulin antagonist inhibited the carbachol-induced pepsinogen secretion and NO generation. Preincubating the cells with L-NMMA had no effect on carbachol-stimulated inositol triphosphate generation or [Ca2+]i or Ca(2+)-dependent adenosine triphosphatase levels. Nitrovasodilator agents and 8-bromo-cGMP stimulated pepsinogen release.

CONCLUSIONS

Gastric chief cells express a Ca2+/calmodulin-dependent NO synthase. NO modulates the stimulatory effect of Ca(2+)-mediated agonists on pepsinogen release.

Idiopathic megarectum in adults. An assessment of manometric and radiologic variables

Outlet obstruction is thought to be one of the major factors responsible for idiopathic constipation. However, outlet obstruction itself may be due to several mechanisms. Among these, the presence of a megarectum is a leading one. Pathophysiological studies in adult patients with idiopathic megarectum are scarce. We studied by manometric and defecographic means 15 adult subjects with idiopathic megarectum and severe chronic constipation. Twenty-five healthy volunteers of both sexes acted as controls. Manometric variables showed significant differences between patients and controls with respect to internal anal sphincter pressure (P = 0.02), minimum relaxation volume (P < 0.001), defecatory sensory threshold (P < 0.001), mean rectal tolerable volume (P < 0.001), and rectal compliance (P < 0.001). An altered response to straining was observed in 46.6% of patients and in 12% of controls (P < 0.04); the ability to expel a 50-ml balloon per anum was 13.3% in patients and 100% in controls (P < 0.001). Although all patients opened the anorectal angle and had descent of the pelvic floor, thereby confirming an adequate expulsion effort, evacuation of contrast material appeared extremely difficult. In fact, no subject was able to expel more than 30% of the rectal contents during fluoroscopic screening. These results confirm previous hypotheses that idiopathic megarectum displays features of a neuropathic process as an underlying mechanism. Further studies are needed that also take into consideration the muscle tone component of the rectum in these patients.

Effect of some abdominal surgical operations on small bowel motility in humans: our experience

Until recently, it was only possible to make inferences about small bowel motility from experimental animal models, but manometric techniques now allow prolonged recordings of small bowel motor activity in humans. We have studied the effect of abdominal surgery on motor behavior of the small intestine and here report our observations after various surgical procedures (total gastrectomy, Billroth I and II gastrectomy, ileoanal anastomosis). We discuss the data together with the experiences of others.

Severe gastric mucosal damage induced by NSAIDs in healthy subjects is associated with Helicobacter pylori infection and high levels of serum pepsinogens

Helicobacter pylori infection and NSAIDs are considered the two most important exogenous factors in ulcer disease. The interrelation between the two factors is not, however, clear. Moreover, serum pepsinogen has been suggested as a risk marker for the development of NSAID-induced gastrointestinal lesions. Fifty-one healthy volunteers, enrolled in a prospective, double-blind study carried out to evaluate gastrointestinal side effects of meloxicam and piroxicam, were analyzed to determine whether: (1) the prevalence of H. pylori correlates with the occurrence and severity of NSAID-induced gastrointestinal lesions, and (2) serum pepsinogen A and C levels could be used as markers of NSAID-induced mucosal damage. Upper endoscopy was performed by the same investigator before and after 28 days of treatment with placebo, meloxicam (7.5 mg/day and 15 mg/day), or piroxicam (20 mg/day). NSAID-induced damage was graded separately for hemorrhages and erosion ulcers according to Lanza's scale. There were no statistically significant differences in the prevalence of H. pylori in subjects with and without NSAID-induced mucosal lesions. However, there was a positive association between H. pylori infection and the severity of mucosal damage: total mean endoscopic score was 2.9 +/- 0.3 in H. pylori-positive subjects versus 1.6 +/- 0.5 in H. pylori-negative subjects (P < 0.05). Pepsinogen A and C levels increased from 55.3 +/- 3 to 149.4 +/- 15 and from 6.3 +/- 0.5 to 11.5 +/- 2.2, respectively (P < 0.05) in subjects who developed severe endoscopic injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Endoplasmic reticulum Ca(2+)-ATPase in microsomal vesicles isolated from bovine retinae

Active Ca2+ transport was measured in microsomal vesicles prepared from bovine retinae and was compared with that in disk membranes of the photoreceptor cells of the same retina. The 45Ca uptake was dependent on the presence of Mg(2+)-ATP and was inhibited by vanadate or when GTP substituted for ATP. The dependence of calcium uptake on the external free Ca2+ concentration gave a KM = 13 microM or a KM = 0.1 microM for disks and microsomal vesicles, respectively. A phosphorylated intermediate (E-P) of Ca(2+)-ATPase of about 100 kDa was isolated in microsomal vesicles. The E-P formation was strongly inhibited by thapsigargin and partially by 2,5-di-(-butyl)benzohydroquinone. Digestion of disks or microsomes with calpain had no effect on the phosphorylated intermediate, while digestion with trypsin produced two fragments of approximately 55 kDa and 35 kDa. These results suggest that bovine retinal microsomes contain a calcium pump belonging to the SERCA family.

Effect of NSAIDs on pepsinogen secretion and calcium mobilization in isolated chief cells

Acid and pepsin are thought to play an important role in the process of gastrointestinal side effects induced by nonsteroidal anti-inflammatory drugs (NSAIDs). Although NSAIDs increase basal gastric acid secretion, the effect they exert on pepsinogen secretion is unknown. Because pepsin plays a key role in many acid-related diseases, we investigated whether NSAIDs directly stimulate pepsinogen secretion from isolated chief cells. Exposure of guinea pig gastric chief cells to indomethacin (10 microM) did not reduce cell viability as evaluated by lactate dehydrogenase and 51Cr release and trypan blue incorporation. Indomethacin (10 microM) caused two- to threefold increases in pepsinogen secretion and intracellular calcium concentrations ([Ca2+]i). Both effects were concentration dependent. Removal of extracellular Ca2+ or pretreatment of the cells with 0.5 mM lanthanum blocked both pepsinogen secretion and the [Ca2+]i increase in chief cells stimulated with 10 microM indomethacin. Exposure of isolated chief cells to indomethacin caused a 90% inhibition of prostaglandin (PG) E2 generation, but a 12-fold increase in leukotriene (LT) B4 release. Incubating chief cells with exogenously added LTB4, LTC4, LTD4, and LTE4 provoked a concentration-dependent stimulation of pepsinogen release (mean effective concentration of 0.05-0.1 nM). Maximally effective concentrations of all LTs (10 microM) increased [Ca2+]i two- to threefold. Pretreating the cells with a 5-lipoxygenase inhibitor abolished LTB4 generation induced by Ca2+ ionophore and indomethacin and reduced indomethacin-induced pepsinogen secretion 20%. In conclusion, indomethacin induced a concentration-dependent stimulation of pepsinogen secretion and [Ca2+]i in isolated chief cells. Indomethacin inhibits PGE2 generation, but increases LTB4 release. This "lipoxygenase shunt" may contribute to the effect indomethacin exerts on isolated chief cells.

Leukotrienes stimulate pepsinogen secretion from guinea pig gastric chief cells by a nitric oxide-dependent pathway

BACKGROUND/AIMS

Leukotrienes (LTs) are involved in many inflammatory conditions including gastric damage induced by nonsteroidal anti-inflammatory drugs. Although LTs stimulate acid secretion, the effect they exert on pepsinogen secretion is unknown. The aim of this study was to investigate whether LTs stimulate pepsinogen secretion by isolated chief cells and to identify the intracellular messengers that mediate this action.

METHODS

Isolated chief cells were incubated with concentrations of LTB4, LTC4, LTD4, or LTE4 ranging from 0.1 pmol/L to 10 mumol/L, and pepsinogen release, intracellular calcium and inositol(1,4,5)-trisphosphate (IP3) concentrations were measured. Nitric oxide generation was determined by the amount of citrulline generated during incubation.

RESULTS

All four LTs caused a concentration-dependent stimulation of pepsinogen secretion with 50% effective concentration of 0.05-0.1 nmol/L and a dose-dependent increase in cytoplasmic free calcium and IP3 concentration. The LTB4 and LTD4 antagonists caused selective, concentration-dependent inhibition of LTB4- and LTD4-induced pepsinogen secretion, calcium mobilization, and IP3 generation. All four LTs increased NO generation, and the effect was inhibited by LTB4 and LTD4 antagonists and an NO synthase inhibitor NG-monomethyl-L-arginine and reversed by L-arginine. NG-monomethyl-L-arginine caused a 50%-60% reduction of LT-induced pepsinogen release. Each of the four LTs caused a fivefold increase in 5'-cyclic guanosine monophosphate.

CONCLUSIONS

LTs are powerful stimulators of pepsinogen secretion in isolated chief cells and act via occupancy of specific cell-surface receptors.

L-arginine/nitric oxide pathway modulates gastric motility and gallbladder emptying induced by erythromycin and liquid meal in humans

There is recent evidence that nitric oxide, a soluble gas produced from L-arginine, is released by the smooth muscle cells and neurons of the gastrointestinal tract where it exerts a myorelaxive action. However, little is known about the effects nitric oxide has on gastric and gallbladder motility during the inter- and postprandial phases in man. We therefore investigated the effects 200 mg/kg/hr L-arginine exerts on the gastric and gallbladder motility induced by 2 mg/kg erythromycin or a liquid meal in 21 subjects in a double-blind, placebo-controlled study. Gastric and gallbladder emptying were evaluated by sonography. Fasting antral motility was expressed as antral motility index (MI). In fasting subjects, L-arginine administration determined a threefold increase in plasma nitrite concentrations. Administration of erythromycin caused a significant rise in the antral MI, which was inhibited by L-arginine (P < 0.05). Ingestion of a liquid meal also significantly increased antral MI, but it returned to basal values 90 min after the end of the meal. Although L-arginine administration caused a significant reduction in the antral MI (P < 0.05), it did not inhibit gastric emptying. L-Arginine provoked an approximately 40% increase in basal gallbladder volume, completely blocked erythromycin-induced emptying, and partially, but significantly, prevented the emptying induced by a liquid meal (P < 0.01). Our study suggests that nitric oxide may be implicated in the physiological modulation of gastric and gallbladder motility during the inter- and postprandial phases in man.

Genetic screening to identify the gene carrier in Italian and German kindreds affected by multiple endocrine neoplasia type 1 (MEN 1) syndrome

Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominantly inherited disorder characterized by parathyroid hyperplasia, anterior pituitary adenomas and neoplasms of the endocrine cells of the gastroenteric tract. It has been established that also other tissues exhibit excessive proliferation associated to the MEN 1 syndrome: carcinoids (bronchial and intestinal), lipomas (visceral and cutaneous), thyroid adenomas and goiter, and adrenal gland cortex adenomas. The men 1 gene has been mapped by genetic studies to the long arm of human chromosome 11, region q12-13. Genetic analysis of families and tumoral deletion mapping made possible to narrow the men 1 region to a 5 cM interval on chromosome 11q12-13. Thirteen marker complexes (17 DNA probes) were found to be linked to the men 1 gene and they span a 14% meiotic recombination with the men 1 locus in the middle. We report a genetic study on 103 subjects from 7 collected MEN 1-kindreds, six Italian and one German, including 30 affected individuals. By linkage analysis to 9 DNA markers (10 DNA probes) of the chromosome region where the men 1 gene maps (11q12-13), we identified 10 mutant gene carriers. The predicted MEN 1 diagnosis was clinically confirmed for 2 of these identified carriers. A predictive accuracy of this genetic test can reach up to 99.5% when it is possible to exclude meiotic crossing-over between the analyzed DNA markers and the disease locus.

Cognitive event-related potential in hepatic encephalopathy

A study of auditory P300 was performed on 24 patients with cirrhosis of the liver: 13 patients with hepatic encephalopathy (HE grade 1-2) and 11 patients without clinical encephalopathy (HE grade 0). The patients were also assessed using spontaneous EEG and neuropsychological methods: Mini Mental State, Digit Span and Number Connection Test. The P3 latency was found to be significantly increased in all patients (100%) with HE grade 1-2 and in 6 patients (54.5%) with HE grade 0. The clinical value of using the P300 latency in the hepatic encephalopathy is subsequently discussed.