Biomedical subjects

F Pallone

Publications and source records attributed to F Pallone.

At least 109 records · Page 6Linked to original sources

PubMed1991

Effects of somatostatin on human intestinal lamina propria lymphocytes. Modulation of lymphocyte activation.

We have investigated the effect of somatostatin (SOM) on the mitogen-induced activation of lamina propria mononuclear cells isolated from the human intestinal mucosa (LPMNC) and of the autologous peripheral blood lymphocytes (PBMNC). The occurrence of specific SOM receptors and their biological characteristics were also investigated. The counts of interleukin-2 receptor (IL-2R)-positive cells after mitogen stimulation were significantly lower in the presence of SOM. This effect of SOM appeared to be dose dependent, with SOM concentrations ranging between 1 pM and 1 microM. The amount of SOM required for the 50% inhibition of this expression was 1000 times lower in the LPMNC population than in the PBMNC. Binding studies showed that human LPMNC bear specific receptors for SOM and demonstrated that the affinity of these receptors was 1000 times higher than that of the SOM receptors present on the PBMNC (Kd 2.1 +/- 0.34 nM vs. 910 +/- 46 nM, respectively). The inhibitory effect of SOM on the proliferative response appeared to be restricted to PBMNC, with a maximal inhibition at 1 nM SOM, while LPMNC proliferative response was poorly affected. SOM inhibited the in vitro immunoglobulin production of both PBMNC and LPMNC over a wide range of concentrations, with a maximal inhibition at 1 nM. At this concentration the effect of SOM on IgA was more pronounced in the PBMNC than in the LPMNC. Our results lend support to the concept that in humans SOM plays a role in the modulation of the immune response at the level of the intestinal mucosa where cell-to-cell interactions between SOM releasing nerve fibers and cells and the immune system occur.

DNA↗

PubMed1991

Serum immunomodulatory factors in gastrointestinal diseases. A 30-50-kD serum fraction in Crohn's disease capable of modulating lymphocyte activation.

We tested the hypothesis that serum factors present in Crohn's disease interfere with the process of lymphocyte activation. The mitogen-induced proliferation and the expression of early activation antigens by normal lymphocytes cultured in the presence of either Crohn's disease sera or sera from different controls were evaluated. The mitogen-induced proliferation was significantly impaired in the presence of Crohn's disease sera. These sera markedly inhibited the mitogen-induced interleukin-2 receptor (IL-2R) expression (48% inhibition), while the effect of sera on the expression of the transferrin receptor and the 4F2 antigen was much less pronounced. Diafiltration experiments showed that the inhibitory effect was confined to a 30-50-kD serum fraction. Such a serum property was not related to the patients' disease activity and disappeared after surgical removal of the affected bowel. The capability of inhibiting the mitogen-induced IL-2R expression was not restricted to Crohn's disease and was observed with sera from other inflammatory and neoplastic gastrointestinal disorders. This study indicates that a marked inhibition of the IL-2R is a mechanism underlying the immunosuppressive property of the serum in Crohn's disease and in other gastrointestinal conditions.

Adult↗

PubMed1991

Spontaneous release of interferon gamma by intestinal lamina propria lymphocytes in Crohn's disease. Kinetics of in vitro response to interferon gamma inducers.

The spontaneous induced release of interferon gamma (IFN gamma) by cultured intestinal lamina propria lymphocytes was investigated in patients with Crohn's disease. In contrast to normal lymphocytes, intestinal lymphocytes from these patients spontaneously released IFN gamma and seemed to contain IFN gamma in their cytoplasm. Autologous peripheral lymphocytes did not release IFN gamma. When stimulated with interferon inducers lamina propria lymphocytes from Crohn's disease tissue showed an increase in IFN gamma release 24 hours after induction with no appreciable further increase over the next two days of culture, while in control cells, either peripheral or intestinal, IFN gamma release progressively increased, peaking 72 hours after induction. These findings indicate that in Crohn's disease the intestinal lymphocytes are stimulated in vivo to produce IFN gamma and that the spontaneous IFN gamma production is compartmentalised to the gut lymphocytes. These data support the concept that locally released IFN gamma has a crucial role in cell interactions in the lamina propria and contribute to the locally occurring immune phenomena in Crohn's disease, including the increased epithelial expression of major histocompatibility complex class II antigens.

Cell Membrane↗

PubMed1991

Human cervical epithelial cells that express HLA-DR associated with viral infection and activated mononuclear cell infiltrate.

The association between the expression of HLA-DR antigens on cervical epithelium and the local immune state of activation in colposcopically obtained biopsy specimens from patients with histologically documented wart virus infection was investigated. In normal cervical epithelium no HLA-DR staining was detected. No or few IL-2R positive cells were found in the contiguous sections. HLA-DR was expressed by epithelial cells in six out of the 14 samples of wart virus infection. The pattern of fluorescence was focal, but strong and diffuse, to the whole epithelial layer. In the six samples with HLA-DR positive epithelium the numbers of IL-2R positive cells in the lamina propria were strongly increased, ranging between 75 and 90%. HLA-DR expression by cervical epithelium was observed in only two of 12 samples from patients with mixed epithelial non-virus related abnormalities. No increase in the numbers of IL-2R positive cells was observed in this group of patients. Additionally, no significant differences in terms of T lymphocyte infiltrate were found among the three groups. The results indicate that wart virus infection is associated with enhanced HLA-DR epithelial expression and they lend support to the concept that in the human cervix the epithelium actively participates in the local immune response.

Cervix Uteri↗

PubMed1991

Phenotypes and spontaneous immunoglobulin production in mononuclear cells suspensions isolated from colonic biopsies of patients with mild active and quiescent ulcerative colitis.

Lamina propria mononuclear cells can be isolated from mucosal specimens of human colon. In the present study, we have explored whether both the phenotypes and functional properties can be studied in lamina propria mononuclear cell suspensions isolated from the same set of endoscopic biopsies in patients with ulcerative colitis. The counts of CD11b+ lamina propria mononuclear cells in mild active ulcerative colitis were significantly higher than those of both quiescent ulcerative colitis and controls. Similarly, the CD16+ and the CD19+ lamina propria mononuclear cells were significantly increased in mild ulcerative colitis patients in comparison to both quiescent ulcerative colitis and control lamina propria mononuclear cells. Lamina propria mononuclear cells from all the biopsy samples appeared to produce detectable amounts of immunoglobulins of the three classes. The production of IgG in mild ulcerative colitis cultures was significantly higher than that observed in quiescent ulcerative colitis and controls. In contrast, the production of IgA in active ulcerative colitis lamina propria mononuclear cell cultures appeared to be significantly lower than that of both quiescent ulcerative colitis and controls. This study shows that morphology, phenotypes, and functional properties can be assessed in lamina propria mononuclear cell suspensions obtained from the same set of endoscopic biopsy samples. We have also shown that changes in phenotypes and functional status of lamina propria mononuclear cells occurred in mild active ulcerative colitis while no significant abnormality of these parameters was found in quiescent ulcerative colitis. This indicates that a normalization of mucosal immune functions occurs in ulcerative colitis patients when complete clinical and histological remission is achieved.

Biopsy↗

PubMed1990

A limiting-dilution analysis of activated circulating B cells in Crohn's disease.

In the present study the spontaneous in vitro production of immunoglobulins G, A, and M by peripheral mononuclear cells was evaluated, in patients with Crohn's disease, in relation to the state of B-cell activation and further characterized by limiting-dilution analysis. A total of 25 patients with Crohn's disease and 10 healthy controls was studied. The proportion of the transferrin receptor-bearing cells in the B7+ subset was higher in active Crohn's disease patients than in either those with quiescent disease or controls. There was a significant rise in the in vitro IgG, IgM, and IgA production in patients with untreated active Crohn's disease compared to either those with untreated quiescent disease or controls. When patients were followed up from the active phase to clinical remission, a significant decrease in the production of IgG and IgM was observed. IgA levels also showed a decrease, although not reaching statistical significance. When the Ig production was analyzed by limiting dilution, no difference was observed between patients and controls in terms of either precursor frequency of Ig-producing cells or patterns of frequency distribution. In both patients and controls a biphasic limiting-dilution profile was observed. This study shows that a significant B-cell activation is present in Crohn's disease patients, which is accompanied by an increase in immunoglobulin production. This study also indicates that in Crohn's disease the increased immunoglobulin production is related to an augmented B-cell clone size rather than to an increased precursor frequency.

B-Lymphocytes↗

PubMed1990

Effects of high in vivo levels of vasoactive intestinal polypeptide on function of circulating lymphocytes in humans.

To examine the possible in vivo significance of the immunomodulatory effects of vasoactive intestinal polypeptide described in vitro, several parameters of peripheral blood lymphocyte function were studied in a patient with a pancreatic endocrine tumor and high circulating levels of vasoactive intestinal polypeptide. There was no imbalance of the circulating lymphocyte subpopulations, and the in vitro responses of the patient's lymphocytes to mitogens were normal. However, there was an increased number (32%) of peripheral lymphocytes expressing interleukin 2 receptor. Serum immunoglobulin M levels were higher than in controls, and the patient's lymphocytes exhibited a spontaneous in vitro immunoglobulin M production higher than normal. Comparable increases in both interleukin 2 receptor expression and immunoglobulin M production were induced in vitro in normal peripheral lymphocyte cultures by the addition of vasoactive intestinal polypeptide concentrations similar to that detected in the patient's plasma. These findings indicate that a modulatory effect of vasoactive intestinal polypeptide on lymphocyte activation and immunoglobulin synthesis may be operating in vivo. They also suggest that vasoactive intestinal polypeptide does not mediate major defects in peripheral blood lymphocyte function in vivo.

Adenoma, Islet Cell↗

PubMed1990

Effects of sucralfate and sulglycotide treatment on active gastritis and Helicobacter pylori colonization of the gastric mucosa in non-ulcer dyspepsia patients.

We conducted a double-blind randomized treatment study on patients affects by non-ulcer dyspepsia in whom multiple biopsy specimens showed active gastritis. Patients were given either 3 g/day of sucralfate (n = 39) or 600 mg/day of sulglycotide (n = 50) for 6 wk, a glycopeptide isolated from pig duodenum constituents. Endoscopy was carried out at baseline and at the end of treatment. We took biopsies from the gastric body (twice) and antrum (six times) at each endoscopy in order to determine grade and extent of gastritis and Helicobacter pylori colonization. Both treatments induced a marked regression of active gastritis (sucralfate group: p less than 0.05 and p less than 0.0001, respectively, in body and in antrum; sulglycotide group: p less than 0.01 and p less than 0.001, respectively). Conversely, Helicobacter pylori colonization remained unchanged at the end of the treatments. At baseline, a close relationship was found between grade of active inflammation in each biopsy and Helicobacter pylori density. After therapy, the association was lost in each treatment group. These results suggest that there can be a remission of active gastritis in patients with non-ulcer dyspepsia even without changes in Helicobacter pylori colonization. This result can be achieved by enhancing the protective properties of the gastric mucosa.

Adult↗

PubMed1989

Ability of human colonic epithelium to express the 4F2 antigen, the common acute lymphoblastic leukemia antigen, and the transferrin receptor. Studies in inflammatory bowel disease and after in vitro exposure to different stimuli.

We investigated the ability of isolated human colonic epithelial cells to express the common acute lymphoblastic leukemia antigen (CALLA), the transferrin receptor, and the 4F2 antigen in response to different types of stimuli. The expression of these markers was assessed by immunofluorescence using monoclonal antibodies. Thirty-two percent of freshly isolated colonic epithelial cells from actively inflamed mucosa of patients with inflammatory bowel disease expressed the 4F2 antigen, 28% the transferrin receptor, and 13% the CALLA. Normal colonic epithelial cells were cultured and the kinetics of expression of the three antigens was studied. A significant increase in the expression of the three markers was observed throughout the culture period in response to the lectin phytohemagglutinin and the epidermal growth factor. The kinetics of expression of the 4F2 antigen and the CALLA after lectin stimulation appeared to differ from that observed after epidermal growth factor. At the end of the cultures one-third of the cells expressed the 4F2 antigen and the transferrin receptor, whereas one-fifth were positive for CALLA. Thus, after these cultures the expression of the three markers was quantitatively similar to that observed with freshly isolated cells from inflamed mucosa. gamma-Interferon markedly induced the 4F2 antigen but had no effect on the transferrin receptor and the CALLA. These data demonstrate that colonic epithelium is capable of expressing the 4F2 antigen and the CALLA in association with the transferrin receptor.

Antibodies, Monoclonal↗

PubMed1988

Postheparin plasma diamine oxidase in patients with small bowel Crohn's disease.

Diamine oxidase (DAO) is an enzyme located almost exclusively in villus tip enterocytes of mammals. Its plasma activity, normally very low, is enhanced by intravenous heparin, which releases the enyzme from small bowel enterocytes into the blood. Plasma postheparin DAO (PHD) values have been shown to be significantly reduced in patients with malabsorption and villous atrophy and inversely correlated with 24-h fecal fat, thus suggesting that PHD reflects the mature enterocytic mass. We have assayed PHD in 51 patients with small bowel Crohn's disease by measuring the area under the plasma DAO curve over a 120-min period after an intravenous bolus of 15,000 IU of heparin. Postheparin plasma DAO was significantly lower (p less than 0.001) in patients (328 +/- 175 U/ml.min) than in 20 normal subjects (508 +/- 101 U/ml.min; range, 391-749). Postheparin diamine oxidase values were inversely correlated with Crohn's disease activity index (CDAI), but no correlation was found with extent of disease assessed radiologically by either double-contrast small bowel enema or barium meal follow-through. In 6 patients with active disease (CDAI, 297 +/- 99) and low PHD values (188 +/- 100 U/ml.min), the assay was repeated after a clinically effective course of antiinflammatory drugs. A significant increase in PHD values (388 +/- 112 U/ml.min) was observed (p less than 0.005). These data indicate that mucosal involvement is common in small bowel Crohn's disease and that PHD may be useful in assessing and monitoring mucosal damage in these patients.

Adult↗

PubMed1988

Clinical and laboratory indicators of extent of ulcerative colitis. Serum C-reactive protein helps the most.

We estimated the extent of the inflammatory mucosal lesion by colonoscopy and biopsy in 60 patients with their first attack of ulcerative colitis. Proctitis was found in 12, proctosigmoiditis in 19, left-sided colitis in 10, and extensive colitis in 19. Fourteen clinical variables and laboratory measurements (bowel frequency, stool consistency, rectal bleeding, fecal mucus/pus, temperature, pulse rate, white blood cell count, hematocrit, sedimentation rate, serum iron, serum albumin, serum alpha 2-globulin, serum C-reactive protein, and seromucoids) were determined. All the variables except rectal bleeding and hematocrit were correlated (p less than 0.001) with the extent of colitis. On stepwise discriminant analysis, only C-reactive protein distinguished proctosigmoiditis from more improved the discrimination. Cross-validation by the "jack-knife method" showed that 86.7% of patients were correctly classified, the errors consisting in underestimation of disease in 8/29 patients with extensive colitis.

Adolescent↗

PubMed1988

The clinical significance of serum C reactive protein levels in Crohn's disease. Results of a prospective longitudinal study.

We measured the serum C reactive protein (CRP) levels by a sensitive immunochemistry method in 101 outpatients with Crohn's disease enrolled in a prospective longitudinal study. At entry, 51 of the 101 patients had raised CRP levels, which showed good correlation with the clinical score. However, one-third of the patients with clinically active disease had normal CRP while one-third of the patients in clinical remission had a raised CRP. The longitudinal study showed that (a) in patients with active disease, CRP levels tended to decrease as the disease went into remission; (b) in patients who achieved remission, the likelihood of clinical relapse after 2 years of entry was higher in those with persistently raised CRP than in those with persistently normal CRP; and (c) in patients with quiescent disease at entry who remained in remission throughout the first year of the study, the likelihood of clinical relapse during the second year of the study was higher for those with persistently raised CRP than for the others. This study confirms that serum CRP is a useful laboratory index for supplementing clinical scores in patients with Crohn's disease, in monitoring the response to treatment, in helping to predict the course of the disease, and in contributing to defining subgroups of patients.

C-Reactive Protein↗

PubMed1988

HLA-D region antigens on isolated human colonic epithelial cells: enhanced expression in inflammatory bowel disease and in vitro induction by different stimuli.

Colonic epithelial cells (CEC) were isolated from actively inflamed mucosa of IBD patients and checked for HLA-DR, HLA-DP, and HLA-DQ. Half of the freshly isolated CEC from IBD tissue expressed DR, and one third were positive for DP and DQ. Normal human CEC were then cultured for 24 h and their expression of these markers in response to different types of in vitro stimulation was investigated. A significant increase in the expression of DR, DP and DQ was observed in response to the nonspecific mitogen phytohaemagglutinin (PHA), the lymphokine gamma-interferon (gamma-IFN) and the epidermal growth factor (EGF). The enhancement of DR expression was more marked than that of DP and DQ. The effect of gamma-IFN was more rapid and significantly more marked than that of either PHA and EGF for all three antigens. EGF appeared to be more potent than PHA in enhancing the expression of DP and DQ. The data from this study indicate that HLA-D region antigens can be induced on human CEC by different types of stimuli and provide further evidence that the expression of these markers in the colonic epithelium is a normal event the magnitude of which can increase under various circumstances. The data also suggest that the increased expression of HLA-D region antigens by IBD CEC occurs as a result of different mechanisms, and that this expression is an indicator of the active participation of the colonic epithelium to the mucosal inflammatory response.

Cells, Cultured↗

PubMed1987

Peripheral and intestinal lymphocyte activation after in vitro exposure to cow's milk antigens in normal subjects and in patients with Crohn's disease.

We studied in Crohn's disease and controls the in vitro activation of either peripheral (PBMNC) or intestinal (LPMNC) mononuclear cells in response to the cow's milk antigen beta-lactoglobulin (Blg). The activation of mononuclear cells was investigated by analyzing the kinetics of the transferrin receptor (T9 antigen) and interleukin 2 receptor (Tac antigen) expression. In both controls and Crohn's disease patients Blg (1 microgram/ml) induced a significant (P less than 0.01) increase of T9 and Tac expression by both PBMNC and LPMNC cultured for 3 days. After Blg exposure the counts of T9- and Tac-bearing cells were significantly (P less than 0.05) higher in PBMNC cultures from healthy controls than in those from patients with Crohn's disease. In both groups peripheral T-enriched cell suspensions did not express T9 and Tac when stimulated with Blg but were restored to express either antigen by the addition of 10% autologous adherent cells. In LPMNC cultures from patients with Crohn's disease the Tac expression after 3 days of Blg stimulation was significantly (P less than 0.05) higher than in the autologous PBMNC. Data from this study indicate that in both controls and patients with Crohn's disease lymphocytes sensitized to Blg occur in the circulation as well as in the gut lamina propria. Our data also suggest that in Crohn's disease an increased proportion of lymphocytes sensitized to Blg are recruited from the circulation into the site of the intestinal lesion.

Adult↗

PubMed1987

Activation of peripheral blood and intestinal lamina propria lymphocytes in Crohn's disease. In vivo state of activation and in vitro response to stimulation as defined by the expression of early activation antigens.

In the present study the state of activation of either peripheral blood and intestinal lamina propria mononuclear cells in Crohn's disease was defined by investigating the expression of early activation antigens (namely the 4F2 antigen, the transferrin receptor and the interleukin-2 receptor). The expression of 4F2 and T9 antigens was greatly increased--in the peripheral blood and in the intestinal lamina propria whereas the proportion of interleukin-2 receptor bearing cells was much less pronounced. The counts of early activation antigens bearing cells in the lamina propria were quite comparable with those of the autologous peripheral cells. In the peripheral blood counts of 4F2 and T9 positive cells were very high in patients with active Crohn's disease but patients with quiescent disease also had a significantly raised proportion of 4F2 and T9 bearing cells. Only in those patients with no evidence of macroscopic disease (namely those resected without recurrence) the counts of early activation antigens bearing cells were within the normal range. The in vitro mitogen induced expression of early activation antigens on either peripheral and intestinal mononuclear cells of patients with Crohn's disease proved to be both quantitatively and qualitatively similar to that of the controls showing the full expression of 4F2, transferrin receptor, and interleukin-2 receptor. While demonstrating that in Crohn's disease there was no intrinsic defect of generation and expression of growth factors receptors by peripheral and intestinal lymphocytes, these results showed that there was a divergence in the expression of early activation antigens in vivo and in vitro. This would indicate that in Crohn's disease there is an in vivo increased population of preactivated rather than fully activated lymphocytes consisting of 4F2 and T9 bearing cells. The high proportion of these cells in the peripheral blood and in the intestine suggests that a chronic immune activation is present in these patients outside as well as within the affected bowel.

Adult↗

PubMed1987

Lymphocyte activation by B. subtilis spores.

The in vitro effect of Bacillus Subtilis spores (BSs) on lymphocyte activation was investigated by analyzing the kinetics of expression of the activation antigens MLR3, MLR4 and HLA-DR in cultures of peripheral mononuclear cells. It was found that BSs over a wide range of concentrations are capable of inducing an increased expression of these three markers and that at high BSs concentration the effect is both quantitatively and qualitatively similar to that induced by the mitogens PHA and ConA. These results suggest that T cells may be involved in the response to Bss.

Bacillus subtilis↗

PubMed1987

HLA-DR antigens on colonic epithelial cells in inflammatory bowel disease: I. Relation to the state of activation of lamina propria lymphocytes and to the epithelial expression of other surface markers.

The colonic epithelial expression of HLA-DR molecules and of other markers of cell membrane perturbation was investigated by immunofluorescence in biopsy specimens from patients with ulcerative colitis and Crohn's disease. It was found that in virtually all specimens from either groups showing active inflammation there was a diffuse epithelial expression of HLA-DR molecules. There was no relation between the grading of active inflammation and the epithelial expression of HLA-DR antigens. The epithelium of virtually all specimens from the macro and microscopically uninvolved areas of patients with active colitis and from patients with histologically quiescent colitis showed no detectable expression of HLA-DR molecules. The counts of isolated lamina propria lymphocytes expressing the transferrin receptor and the interleukin 2 receptor were higher in specimens with HLA-DR+ epithelium than in those with a HLA-DR- epithelium. Twenty-nine of the 35 (83%) HLA-DR positive specimens proved to express the 4F2 antigen on their epithelium and 19 (54%) were positive for the transferrin receptor. All sections positive for either the 4F2 antigen or the transferrin receptor were also HLA-DR positive while all HLA-DR negative sections were also negative for either of the two other markers. Data in this study suggest that in active IBD the epithelial participation in active inflammation is associated with a sequence of cell membrane rearrangements, and that the expression of HLA-DR molecules is a part of this sequence.

Antigens, Surface↗

PubMed1987

Campylobacter-like organisms on the human gastric mucosa. Relation to type and extent of gastritis in different clinical groups.

Three hundred and thirty-four pyloric type and 244 fundic type gastric mucosal specimens from 135 patients undergoing upper gastrointestinal endoscopy were checked for Campylobacter-like organisms (CLO) by the Warthin-Starry method. CLOs were found in 77/135 (57 p. 100) patients and in 235/578 (41 p. 100) biopsy specimens. There was no significant difference in the prevalence of CLO-positive specimens in the two types of gastric mucosa. The prevalence of CLO-positive specimens was higher in patients with duodenal ulcer than in the other patients (p less than 0.01). In the whole group, 42 p. 100 of the specimens with gastritis showed CLOs. Neither the type nor the activity of gastritis seemed to be relevant. Twenty-two per cent of the pyloric type and 36 p. 100 of the fundic type specimens classed as normal were positive for CLOs. In the normal fundic type mucosa, CLO-positive specimens were more frequent (p less than 0.01) in those patients with CLO-positive specimens from the antral area than in those without CLOs in the antrum. In 41 patients with multiple specimens from either the duodenal bulb and the stomach, chronic non specific duodenitis appeared to be more frequent in patients with CLO-positive antral specimens. The present study provided data on the frequency of gastric CLOs in a mediterranean population and confirmed that an association between CLOs and antral gastritis exists in patients with duodenal ulceration. However, data of the present investigation indicate that no relation between CLOs and the type and activity of gastritis exists and that CLOs are frequently found in the histologically normal mucosa, particularly in the body-gland area.

Campylobacter↗