Upper gastrointestinal endoscopic findings in celiac disease at diagnosis: A multicenter international retrospective study

BACKGROUND

Gastroduodenal endoscopy and biopsy following positive specific serology is considered the gold standard to diagnose celiac disease (CeD) in adults. Whether upper endoscopy helps detect comorbid conditions is unknown.

AIM

To investigate the prevalence of non-celiac endoscopic findings in patients in whom endoscopy was performed to confirm CeD diagnosis.

METHODS

This is an observational, descriptive, multicenter, retrospective study that reports endoscopic findings obtained in adult patients enrolled in local registries from four tertiary centers. We collected data reported on first endoscopy, indicated for investigation of CeD. Diagnosis of CeD was performed by histology (≥ Marsh 2 type mucosal damage) and specific serology. Two European and one North American center included biopsy-confirmed CeD following positive serology. A fourth center (South America) included symptomatic patients undergoing endoscopy, irrespective of CeD serology. The latter cohort included a non-CeD control group.

RESULTS

A total of 1328 patients (80% female; 35 years median age) were enrolled, of whom 95.6% had positive specific serology. In 135 patients, endoscopy revealed 163 abnormalities unrelated to CeD (prevalence: 10.1%). Erosive reflux esophagitis (6.4%), gastric erosions (2.0%), and suspicion of esophageal metaplasia (1.2%) were the most common findings. Biopsy-confirmed Barrett’s esophagus was infrequent (0.2%). No endoscopic cancer was detected. Older patients (≥ 51 years of age) had a higher prevalence of endoscopic findings than those ≤ 50 (P < 0.01). Within the South American cohort, CeD was associated with a lower rate (8.2%) of comorbid endoscopic findings compared with controls (29.1%; P < 0.001). In the adjusted multivariate analysis of this cohort, having CeD was associated with a 72% reduction in the risk of any endoscopic abnormality (P < 0.0001), and having alarm symptoms was associated with a 37% reduction in the risk of finding at least one endoscopic lesion (P < 0.02).

CONCLUSION

In this large multicenter study, young adults with positive CeD serology had few comorbid endoscopic findings. Although patients over 51 years had a high prevalence of non-CeD gastroduodenal mucosal damage, no malignancy or premalignant lesions were found.

Real-World Gluten Exposure in Patients With Celiac Disease on Gluten-Free Diets, Determined From Gliadin Immunogenic Peptides in Urine and Fecal Samples

BACKGROUND & AIMS

It is not clear how often patients who are on gluten-free diets (GFDs) for treatment of celiac disease still are exposed to gluten. We studied levels of gluten immunogenic peptides (GIP) in fecal and urine samples, collected over 4 weeks, from patients with celiac disease on a long-term GFD.

METHODS

We performed a prospective study of 53 adults with celiac disease who had been on a GFD for more than 2 years (median duration, 8 y; interquartile range, 5-12 y) in Argentina. At baseline, symptoms were assessed by the celiac symptom index questionnaire. Patients collected stool each Friday and Saturday and urine samples each Sunday for 4 weeks. We used a commercial enzyme-linked immunosorbent assay to measure GIP in stool and point-of-care tests to measure GIP in urine samples.

RESULTS

Overall, 159 of 420 stool and urine samples (37.9%) were positive for GIP; 88.7% of patients had at least 1 fecal or urine sample that was positive for GIP (median, 3 excretions). On weekends (urine samples), 69.8% of patients excreted GIP at least once, compared with 62.3% during weekdays (stool). The number of patients with a sample that was positive for GIP increased over the 4-week study period (urine samples in week 1 vs week 4: P < .05). Patients with symptoms had more weeks in which GIP was detected in stool than patients without symptoms (P < .05). The number of samples that were positive for GIP correlated with titers of deamidated gliadin peptide IgA in patients' blood samples, but not with levels of tissue transglutaminase.

CONCLUSIONS

Patients with celiac disease on a long-term GFD still frequently are exposed to gluten. Assays to detect GIP in stool and urine might be used to assist dietitians in assessment of GFD compliance.

Abordaje diagnóstico de la diarrea crónica

Chronic diarrhea is a frequent reason for the referral to the specialist and its prevalence is estimated at around from 4 to 5%. Reaching an etiological diagnosis is a real clinical challenge. The pathophysiological mechanisms involved in its genesis are multiple and sometimes coexist in the same individual. A correctly oriented anamnesis and physical examination will allow to identify key data, mainly the presence of symptoms or alarm signs with the intention of discriminating between the functional and the organic causes. The doctor must know how to use his clinical judgment, evaluate the probabilities and use the diagnostic methods available with the precise orientation to adapt them to each particular case. The categorization of diarrhea as watery, malabsorptive or inflammatory attempts to simplify the diagnostic process, although it is only indicative. The objective of the following review is to present the different pathophysiological mechanisms involved in chronic diarrhea, as well as the available diagnostic and therapeutic tools that allow us to carry out an adequate approach for its study.

Effect of Bifidobacterium infantis NLS super strain in symptomatic coeliac disease patients on long-term gluten-free diet - an exploratory study

Bifidobacterium infantis NLS super strain (B. infantis NLS-SS) was previously shown to alleviate gastrointestinal symptoms in newly diagnosed coeliac disease (CD) patients consuming gluten. A high proportion of patients following a gluten-free diet experiences symptoms despite dietary compliance. The role of B. infantis in persistently symptomatic CD patients has not been explored. The aim of the study was to evaluate the effect of B. infantis NLS-SS on persistent gastrointestinal symptoms in patients with CD following a long-term GFD. We conducted a randomised, cross-over, double-blind, placebo-controlled trial in symptomatic adult CD patients on a GFD for at least two years. After one-week run-in, patients were randomised to B. infantis NLS-SS or placebo for 3 weeks with cross-over after a 2-week wash-out period. We estimated changes (Δ) in celiac symptom index (CSI) before and after treatment. Stool samples were collected for faecal microbiota analysis (16S rRNA sequencing). Gluten immunogenic peptide (GIP) excretion in stool and urine samples was measured at each study period. Eighteen patients were enrolled; six patients were excluded due violations in protocol. For patients with the highest clinical burden, CD symptoms were lower in probiotic than in placebo treatment (P=0.046). B. infantis and placebo treated groups had different microbiota profiles as assessed by beta diversity clustering. In probiotic treated groups, we observed an increase in abundance of B. infantis. Treatment with B. infantis was associated with decreased abundance of Ruminococcus sp. and Bifidobacterium adolescentis. GIP excretion in stools and urine was similar at each treatment period. There were no differences in adverse effects between the two groups. B. infantis NLS-SS improves specific CD symptoms in a subset of highly symptomatic treated patients (GFD). This is associated with a shift in stool microbiota profile. Larger studies are needed to confirm these findings. ClinicalTrials.gov: NCT03271138.

Gluten immunogenic peptide excretion detects dietary transgressions in treated celiac disease patients

BACKGROUND

Life-long removal of gluten from the diet is currently the only way to manage celiac disease (CeD). Until now, no objective test has proven useful to objectively detect ingested gluten in clinical practice. Recently, tests that determine consumption of gluten by assessing excretion of gluten immunogenic peptides (GIP) in stool and urine have been developed. Their utility, in comparison with conventional dietary and analytical follow-up strategies, has not been fully established.

AIM

To assess the performance of enzyme-linked immunosorbent assay (ELISA) and point-of-care tests (PoCTs) for GIP excretion in CeD patients on gluten-free diet (GFD).

METHODS

We conducted an observational, prospective, cross-sectional study in patients following a GFD for at least two years. Using the Gastrointestinal Symptom Rating Scale questionnaire, patients were classified at enrollment as asymptomatic or symptomatic. Gluten consumption was assessed twice by 3-d dietary recall and GIP excretion (by ELISA in stool and PoCTs (commercial kits for stool and urine) in two consecutive samples. These samples and dietary reports were obtained 10 day apart one from the other. Patients were encouraged to follow their usual GFD during the study period.

RESULTS

Forty-four patients were enrolled, of which 19 (43.2%) were symptomatic despite being on a GFD. Overall, 83 sets of stool and/or urine samples were collected. Eleven out of 44 patients (25.0%) had at least one positive GIP test. The occurrence of at least one positive test was 32% in asymptomatic patients compared with 15.8% in symptomatic patients. GIP was concordant with dietary reports in 65.9% of cases (Cohen´s kappa: 0.317). PoCT detected dietary indiscretions. Both ELISA and PoCT in stool were concordant (concomitantly positive or negative) in 67 out of 74 (90.5%) samples. Excretion of GIP was detected in 7 (8.4%) stool and/or urine samples from patients considered to be strictly compliant with the GFD by dietary reports.

CONCLUSION

GIP detects dietary transgressions in patients on long-term GFD, irrespective of the presence of symptoms. PoCT for GIP detection constitutes a simple home-based method for self-assessment of dietary indiscretions.

Impaired Bone Microarchitecture Improves After One Year On Gluten-Free Diet: A Prospective Longitudinal HRpQCT Study in Women With Celiac Disease

We have recently identified a significant deterioration of bone microarchitecture in premenopausal women with newly diagnosed celiac disease (CD) using high-resolution peripheral quantitative computed tomography (HRpQCT). The aim of this work was to assess changes in bone microarchitecture after 1 year on a gluten-free diet (GFD) in a cohort of premenopausal women. We prospectively enrolled 31 consecutive females at diagnosis of CD; 26 of them were reassessed 1 year after GFD. They all underwent HRpQCT scans of distal radius and tibia, areal BMD by DXA, and biochemical tests (bone-specific parameters and CD serology) at both time points. Secondary, we compared 1-year results with those of a control group of healthy premenopausal women of similar age and BMI in order to assess whether the microarchitectural parameters of treated CD patients had reached the values expected for their age. Compared with baseline, the trabecular compartment in the distal radius and tibia improved significantly (trabecular density, trabecular/bone volume fraction [BV/TV] [p < 0.0001], and trabecular thickness [p = 0.0004]). Trabecular number remained stable in both regions. Cortical density increased only in the tibia (p = 0.0004). Cortical thickness decreased significantly in both sites (radius: p = 0.03; tibia: p = 0.05). DXA increased in all regions (lumbar spine [LS], p = 0.01; femoral neck [FN], p = 0.009; ultradistal [UD] radius, p = 0.001). Most parameters continued to be significantly lower than those of healthy controls. This prospective HRpQCT study showed that most trabecular parameters altered at CD diagnosis improved significantly by specific treatment (GFD) and calcium and vitamin D supplementation. However, there were still significant differences with a control group of women of similar age and BMI. In the prospective follow-up of this group of patients we expect to be able to assess whether bone microarchitecture attains levels expected for their age. © 2016 American Society for Bone and Mineral Research.

Significant bone microarchitecture impairment in premenopausal women with active celiac disease

Patients with active celiac disease (CD) are more likely to have osteoporosis and increased risk of fractures. High-resolution peripheral quantitative computed tomography (HR-pQCT) permits three-dimensional exploration of bone microarchitectural characteristics measuring separately cortical and trabecular compartments, and giving a more profound insight into bone disease pathophysiology and fracture. We aimed to determine the volumetric and microarchitectural characteristics of peripheral bones-distal radius and tibia-in an adult premenopausal cohort with active CD assessed at diagnosis. We prospectively enrolled 31 consecutive premenopausal women with newly diagnosed CD (median age 29 years, range: 18-49) and 22 healthy women of similar age (median age 30 years, range 21-41) and body mass index. Compared with controls, peripheral bones of CD patients were significantly lower in terms of total volumetric density mg/cm(3) (mean ± SD: 274.7 ± 51.7 vs. 324.7 ± 45.8, p 0.0006 at the radius; 264.4 ± 48.7 vs. 307 ± 40.7, p 0.002 at the tibia), trabecular density mg/cm(3) (118.6 ± 31.5 vs. 161.9 ± 33.6, p<0.0001 at the radius; 127.9 ± 28.7 vs. 157.6 ± 15.6, p < 0.0001 at the tibia); bone volume/trabecular volume ratio % (9.9 ± 2.6 vs. 13.5 ± 2.8, p<0.0001 at the radius; 10.6 ± 2.4 vs. 13.1 ± 1.3, p < 0.0001 at the tibia); number of trabeculae 1/mm (1.69 ± 0.27 vs. 1.89 ± 0.26, p 0.009 at the radius; 1.53 ± 0.32 vs. 1.80 ± 0.26, p 0.002 at the tibia); and trabecular thickness mm (0.058 ± 0.010 vs. 0.071 ± 0.008, p < 0.0001 at the radius with no significant difference at the tibia). Cortical density was significantly lower in both regions (D comp mg/cm(3) 860 ± 57.2 vs. 893.9 ± 43, p 0.02; 902.7 ± 48.7 vs. 932.6 ± 32.6, p 0.01 in radius and tibia respectively). Although cortical thickness was lower in CD patients, it failed to show any significant inter-group difference (a-8% decay with p 0.11 in both bones). Patients with symptomatic CD (n = 22) had a greater bone microarchitectural deficit than those with subclinical CD. HR-pQCT was used to successfully identify significant deterioration in the microarchitecture of trabecular and cortical compartments of peripheral bones. Impairment was characterized by lower trabecular number and thickness-which increased trabecular network heterogeneity-and lower cortical density and thickness. In the prospective follow-up of this group of patients we expect to be able to assess whether bone microarchitecture recovers and to what extend after gluten-free diet.

The role of small woodland remnants on ground dwelling insect conservation in Chaco Serrano, Central Argentina

Many terrestrial ecosystems are changing due to extensive land use and habitat fragmentation, posing a major threat to biodiversity. In this study, the effects of patch size, isolation, and edge/interior localization on the ground dwelling insect communities in the Chaco Serrano woodland remnants in central Argentina were examined. Sampling was carried out in December 2003 and March 2004 in nine remnants (0.57 to 1000 hectares) using pitfall traps. In total, 7071 individuals representing 12 orders and 79 families were recorded. The taxonomic composition of these communities was linked to remnant size. Insect abundance increased (as did their richness, albeit marginally) as remnant area decreased, with no significant effects of isolation or edge/interior localization on abundance, richness, or diversity. No differential area effects were observed when abundance and richness of predators, scavengers, and herbivores were compared. Thus, ground insect communities in fragmented Chaco Serrano seem to respond mainly to patch level, rather than to within-patch (edge effects) or landscape (isolation) level variables. These results suggest that small Chaco Serrano remnants, by supporting larger ground-dwelling insect assemblages, may play an important role from a conservation viewpoint.

Analysis and characterization of cultivable extremophilic hydrolytic bacterial community in heavy-metal-contaminated soils from the Atacama Desert and their biotechnological potentials

AIMS

To isolate and characterize the cultivable community of hydrolase producers (amylase, protease, lipase, DNase, xylanase and pullulanase) inhabiting heavy-metal-contaminated soils in extreme conditions from the Atacama Desert.

METHODS AND RESULTS

A total of 25 bacterial strains showing hydrolytic activities have been selected including halotolerants, extremely halotolerants and moderate halophiles. Most hydrolase producers were assigned to the family B acillaceae, belonging to the genera Bacillus (nine strains), Halobacillus (seven strains) and Thalassobacillus (five strains) and four isolates were related to members of the families Pseudomonadaceae, Halomonadaceae and Staphylococcaceae. The selected strains were then characterized for their tolerance pattern to six heavy metals, measured as minimal inhibitory concentrations (MICs).

CONCLUSIONS

The diversity found in the cultivable bacterial community analysed is more limited than that detected in other ecological studies owing to the restrictive conditions used in the screening. The dominant bacteria were Firmicutes and particularly, species related to the genus Bacillus.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is focused on the characterization of extremophilic hydrolytic bacteria, providing candidates as a source of novel enzymes with biotechnological applications.

Accuracy of testing for antibodies to synthetic gliadin-related peptides in celiac disease

BACKGROUND & AIMS

Our aim was to explore the diagnostic value of a newly developed synthetic peptide antibody assay addressing specific synthetic gliadin-derived deamidated peptides (AGA II) for the diagnosis of celiac disease (CD).

METHODS

We assayed serum samples obtained prospectively at diagnosis from a population of 92 consecutive adult patients with CD and 113 non-CD controls. Patients were reevaluated after 6 months (n = 56) and 1 year (n = 20) of treatment. All patients and controls underwent intestinal biopsy and a set of CD-related serology tests. A newly developed enzyme-linked immunosorbent assay (ELISA) for detecting IgA and IgG antibodies against synthetic deamidated gliadin epitopes was used.

RESULTS

At diagnosis, sensitivity and specificity were 94.6% and 99.1% for AGA II IgA and 92.4% and 100% for AGA II IgG. Absolute values and the proportion of positive samples for both antibodies were significantly reduced at 6 months (P < .0000) and 1 year (P < .001) after initiation of a gluten-free diet. Compared with conventional AGA, the peptide antibodies had greater sensitivity, specificity, positive and negative predictive values, accuracy, and likelihood ratios. Compared with antitissue transglutaminase antibodies, AGA II had similar sensitivity but greater specificity and predictive values, better likelihood ratios, and an excellent agreement (kappa statistic = .92).

CONCLUSIONS

This study assessed the value of an ELISA assay in detecting antibodies to gliadin-related peptides. This assay appears to be a reliable tool for diagnosing CD and suggests promising accuracy that may be very useful in clinical practice.

The IL-1 gene family and bone involvement in celiac disease

Celiac disease (CD) is associated with decreased bone mineral mass. Its pathogenesis is multifactorial since both systemic and local mechanisms may play a role. Our objective was to determine whether single-nucleotide polymorphisms in genes encoding members of the interleukin-1 family are associated with bone damage measured by densitometry in a series of 71 adult CD patients assessed at diagnosis. When compared with non-carrier CD patients, carriers of allele T of the interleukin-1beta gene (IL1B-511T) had a significantly lower bone mass at the total skeleton level (p = 0.0484) and a greater prevalence of osteopenia/osteoporosis (p = 0.0102). To our knowledge, this is the first evidence on the association between a genetic predisposition and low bone mass in CD patients. This finding supports the postulated inflammation-associated bone loss pathogenesis as one of the causes of bone weakness in CD.

Permeability, zonulin production, and enteropathy in dermatitis herpetiformis

BACKGROUND & AIMS

Dermatitis herpetiformis (DH) is characterized by variable degrees of enteropathy and increased intestinal permeability. Zonulin, a regulator of tight junctions, seems to play a key role in the altered intestinal permeability that characterizes the early phase of celiac disease. Our aim was to assess both intestinal permeability and serum zonulin levels in a group of patients with DH having variable grades of enteropathy.

METHODS

We studied 18 DH patients diagnosed on the basis of characteristic immunoglobulin (Ig)A granular deposits in the dermal papillae of noninvolved skin. Results were compared with those of classic celiac patients, patients with linear IgA dermatosis, and healthy controls.

RESULTS

According to Marsh's classification, 5 patients had no evidence of enteropathy (type 0), 4 patients had type II, 2 patients had type IIIb damage, and 7 patients had a more severe lesion (type IIIc). Intestinal permeability (lactulose/mannitol ratio [lac/man]) was abnormal in all patients with DH. Patients with more severe enteropathy had significantly greater permeability ( P < .05). The serum zonulin concentration (enzyme-linked immunosorbent assay) for patients with DH was 2.1 +/- .3 ng/mg with 14 of 16 (87.5%) patients having abnormally increased values. In contrast, patients with linear IgA dermatosis had normal histology, normal intestinal permeability, and negative celiac serology.

CONCLUSIONS

Increased intestinal permeability and zonulin up-regulation are common and concomitant findings among patients with DH, likely involved in pathogenesis. Increased permeability can be observed even in patients with no evidence of histologic damage in biopsy specimens. Patients with linear IgA dermatosis appear to be a distinct population with no evidence of gluten sensitivity.

Significance of smooth muscle/anti-actin autoantibodies in celiac disease

BACKGROUND/AIM

Smooth muscle antibody (SMA) specific for the protein actin, a major component of the cytoskeleton of epithelial cells, is one of the most prevalent non-organ specific autoantibodies in the serum of celiac disease (CD) patients. Our aim was to explore the clinical relevance of the presence of IgA type anti-actin antibody (AAA) and SMA in a series of patients with CD.

METHODS

We evaluated frozen serum samples collected at diagnosis from 92 adult patients with CD and 52 control individuals in whom CD was excluded. Patients were re-evaluated a median time of 5 yr after treatment. IgA type AAA was detected using a modified commercial ELISA assay and IgA SMA was detected using indirect immunofluorescence on primate esophagus substrate.

RESULTS

At diagnosis, samples from CD patients had significantly higher AAA values than controls (p<0.00001). While all active CD patients had serum AAA values over the cut-off for healthy controls, we observed a very significant reduction of these antibodies after treatment (p>0.0001). AAA had a highly significant correlation with both, tissue, transglutaminase (r=0.62) and antigliadin (r=0.60, p<0.00001) antibodies as well as the severity of the intestinal injury (p<0.05). SMA was detected in sera of 35 consecutive CD patients. At diagnosis, SMA positive patients had significantly higher values of AAA (p<0.0002), increased number of autoimmune disorders (p<0.04), delayed menarche (p<0.04), lower hemoglobin levels (p<0.01), increased fecal a-I antitrypsin clearance (p<0.01) and more severe diarrhea (p<0.06). We also detected a trend to more severe complications at follow-up (p=0.059).

CONCLUSIONS

Based on our findings we suggest that the presence of increased IgA AAA serum levels is a highly sensitive marker of the disturbed architecture of intestinal epithelial cells of CD patients with a potential relevance to diagnosis and follow-up. The presence of SMA seems to define a distinct subset of CD patients with a more severe clinical outcome.

Antibodies to human recombinant tissue transglutaminase may detect coeliac disease patients undiagnosed by endomysial antibodies

BACKGROUND

The screening and diagnosis of coeliac disease have been simplified by the advent of new serological tools.

AIM

To assess the clinical utility of a newly developed kit for antibodies to human recombinant tissue transglutaminase (hu-anti-tTG) in a large population of patients undergoing intestinal biopsy for suspected intestinal disorders.

METHODS

We evaluated 426 serum samples from consecutive adult patients (250 from untreated coeliac disease patients and 176 from individuals in whom a diagnosis of coeliac disease had been excluded), obtained at the time of intestinal biopsy. Samples were tested for immunoglobulin A (IgA) hu-anti-tTG by enzyme-linked immunoabsorbent assay, IgA endomysial antibodies (EmA) by indirect immunofluorescence and IgA and IgG antigliadin antibodies by enzyme-linked immunoabsorbent assay. A sub-group of samples was also assessed for a guinea-pig-based anti-tissue transglutaminase.

RESULTS

According to the cut-off for hu-anti-tTG, the sensitivity, specificity and positive and negative predictive values were 91%, 96%, 97% and 87%, respectively. Simultaneous determination of EmA showed values of 86%, 100%, 100% and 83% for the same parameters. Although 19 coeliac disease patients (7.6%) were negative for EmA and hu-anti-tTG, both tests rendered superior statistical values to antigliadin antibody tests. At diagnosis, IgA deficiency was detected in 11 patients, but both assays were able to detect samples with mild to moderate deficiency. The comparison of hu-anti-tTG with EmA showed excellent concordance between the tests (kappa statistic, 0.85). Discordance was observed in 20 samples from coeliac disease patients (8%) and in nine samples from controls (5%). Fifteen samples had an EmA-negative but hu-anti-tTG-positive serology, and five showed the converse pattern. Comparison of human recombinant and guinea-pig tests showed concordant results in 96% of cases.

CONCLUSIONS

The quantitative determination of hu-anti-tTG type IgA using a commercial enzyme-linked immunoabsorbent assay kit was highly sensitive and specific for the detection of coeliac disease. Our results in a large population of patients with a clinical condition suggestive of the disorder demonstrated that the test can be used to detect a substantial number of patients otherwise unrecognized by IgA EmA.

Virulence factors and pathogenicity of Vibrio vulnificus strains isolated from seafood

The virulence factors of Vibrio vulnificus are not yet well understood. So far, many hydrolytic enzymes have been implicated in the pathogenesis of this micro-organism. The present research was carried out in order to study the presence of some of these enzymes in 133 V. vulnificus strains isolated from 45 seafood samples. The results showed that 100% of these strains were positive for the production of lecithinase and lipase (Tween-80), 99.2% for caseinolytic protease, 96.9% for DNase, 65.4% for mucinase and 46.6% for elastase. None of the strains was positive for the production of collagenase and 96% were haemolytic against sheep blood cells. In relation to colony morphology on brain heart infusion (BHI) agar and nutrient agar, 59.4% of strains showed opaque morphology on BHI agar and 57.9% on nutrient agar, 10.5% presented translucent morphology on both agars and 30.1 and 31.6% of strains showed a mixture of opaque and translucent morphology on BHI agar and nutrient agar, respectively. None of the translucent colonies was virulent to mice. Therefore, opacity was a useful marker for potential virulence. Of 45 food samples contaminated with V. vulnificus, 29 (64.4%) presented strains lethal to adult mice.

Interlaboratory study of the analysis of ampicillin by liquid chromatography

A liquid chromatographic method for the analysis of ampicillin was examined in a collaborative study involving seven laboratories. The method included an isocratic part, which is used in the assay. The isocratic part is similar to the assay method for ampicillin of the US Pharmacopeia XXIII Revision. When the isocratic part is combined with gradient elution, the method is suitable for purity control. Six samples of ampicillin (anhydrous, trihydrate and sodium salt) with varying purity were analysed. The main component and related substances were determined. An analysis of variance proved the absence of consistent laboratory bias. The laboratory-sample interaction was significant. Estimates of the repeatability and reproducibility of the method, expressed as standard deviations of the result of the determination of ampicillin, were calculated to be about 0.9 and 1.1 respectively.

Evaluation of liquid chromatography methods for the separation of ampicillin and its related substances

Two laboratories collaborated to examine the selectivity of four isocratic liquid chromatography (LC) methods for the separation of ampicillin and its related substances. The United States Pharmacopeia (USP) assay method gave the best selectivity. Similar selectivity was obtained on C18 columns as well as on C8 and poly(styrene-divinylbenzene) copolymer columns. A resolution test using cefradine was proposed to replace the test with caffeine prescribed by the USP. Based on the USP method, a gradient LC method was developed for the analysis of related substances in ampicillin. This LC method has been proposed for assay and purity control in the ampicillin monographs of the European Pharmacopeia.

Cyclosporine effects on in vitro responsiveness of anterior pituitary hormone release to dopamine and thyrotropin-releasing hormone in young female rats

Endocrine side effects of the immunosuppressive drug cyclosporine (CyA) include changes in anterior pituitary hormone secretion. The aim of the present study was to examine the effects of CyA on the responsiveness of in situ and ectopic anterior pituitary prolactin (PRL), growth hormone (GH) and luteinizing hormone (LH) release response to dopamine (DA) and thyrotropin-releasing hormone (TRH) treatment in young female rats, and to evaluate the possible PRL participation in these effects. Thirty day old rats were rendered hyperprolactinemic by transplanting an anterior pituitary gland of a littermate donor, under the kidney capsule, and were then injected with CyA or vehicle for 2 or 8 days. Sham-operated rats were used as controls and treated in the same way. CyA treatment prevented the increase in plasma PRL levels which occurred in controls after pituitary grafting. In vitro basal PRL release of in situ pituitaries from either sham-operated and/or pituitary-grafted animals was decreased by CyA treatment at any point studied. Basal in vitro secretion of GH was only decreased in the in situ pituitaries from grafted animals after 2 days of CyA therapy. The presence of an ectopic pituitary lead to an increase in the in vitro basal LH secretion from in situ pituitaries as compared to those from sham-operated rats. Basal LH release rates were not changed by CyA treatment, although the LH release in vitro did increase in the in situ pituitaries from sham-operated animals treated with the drug for 2 days. DA addition to the incubation media decreased the in vitro release of PRL, GH and LH from the in situ pituitaries of sham-operated and pituitary-grafted animals treated with vehicle. In CyA treated animals, DA decreased in vitro PRL release from the in situ pituitaries of animals, independently of the presence or absence of an ectopic pituitary. Reductions of the in vitro GH and LH release release after DA treatment were higher in the in situ pituitaries from grafted animals on day 8 of CyA or vehicle treatment. TRH increased the in vitro release of the three hormones with differential effects related to the length of the treatment with CyA and/or the presence of an ectopic pituitary. In vitro release of PRL and GH by ectopic pituitaries was inhibited by previous treatment with CyA and this effect was decreased proportional to the duration of the treatment with the drug, while LH secretion was not modified. Addition of DA to the incubation media resulted in a marked reduction of in vitro PRL and GH release, but only at day 8 of vehicle treatment on GH release did DA addition to media further decrease the release of both hormones from ectopic pituitaries from animals treated for 2 or 8 days with the drug, whereas LH secretion was not modified. TRH addition to the incubation media of ectopic pituitaries surprisingly reduced PRL and GH secretion on day 8 of CyA treatment or after surgery. The results of these studies suggest that CyA can act directly at the hypophyseal level modifying pituitary responsiveness to external stimuli. CyA seems to exert its main effects on lactotroph activity while its effects on somatotrophs and gonadotrophs are less.

Effects of cyclosporine on ovarian function in sham-operated and pituitary-grafted young female rats

Effects of cyclosporine (CyA) on ovarian function and the possible role of prolactin in mediating these effects were examined in young female rats. The animals were sham-operated or rendered hyperprolactinemic by transplanting pituitary glands under the renal capsule. Cyclosporine prevented the increase in plasma prolactin levels in grafted rats. However, in sham-operated animals plasma prolactin levels were increased after 8 days of CyA treatment. Plasma levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were reduced 8 days after pituitary grafting and increased by CyA at both Day 2 and Day 8 of treatment. The content of LHRH in the hypothalamus was not affected on Day 2 but was reduced on Day 8 after grafting on CyA therapy. Plasma estradiol levels were increased by CyA in sham-operated rats on Day 2 and 8 of treatment, and in pituitary-grafted rats on Day 8 of therapy. In sham-operated rats, ovarian estradiol content was reduced after 2 and after 8 days of CyA administration. In pituitary-grafted rats, the ovarian estradiol content was suppressed after 8 days, and CyA treatment prevented this effect. Ovarian estradiol release in vitro under basal conditions was greater in ovaries derived from 38-day-old than in those from 32-day-old animals. The ovarian estradiol response to human chorionic gonadotropin (hCG) in vitro was increased 2 days after pituitary transplantation. Administration of CyA for 8 days increased basal and hCG-stimulated estradiol release in both sham-operated and pituitary-grafted animals. The present findings suggest that CyA can alter ovarian function by acting directly at the gonadal level. However, a hypothalamic-hypophyseal site of action cannot be ruled out.

Effects of cyclosporine at the hypothalamic-pituitary axis in pituitary-grafted young female rats

This work was designed to investigate the effects of cyclosporine on prolactin secretion by an ectopically grafted heterologous pituitary gland, and on the hypothalamic content of norepinephrine, dopamine and serotonin. The administration of cyclosporine prevented the augmentation in plasma prolactin levels which occurred following an ectopic graft of a litter-mate pituitary gland. In contrast, in sham-operated rats, cyclosporine increased prolactin levels on day 8 of treatment. Both pituitary grafting and cyclosporine treatment in sham-operated rats decreased hypothalamic norepinephrine content. In grafted rats, cyclosporine returned hypothalamic norepinephrine to normal. Hypothalamic serotonin content decreased 8 days after pituitary grafting but increased to the values of control animals after cyclosporine administration. Cyclosporine treatment for 2 and 8 days increased serotonin content in sham-operated animals. As expected, the hypothalamic dihydroxphenylacetic acid/dopamine index increased after pituitary grafting and administration of cyclosporine for 8 days resulted in a further increase. Cyclosporine administration for 2 days, however, decreased this index to the values observed in control animals while drug treatment of control rats for 8 days decreased the dihydroxyphenylacetic acid/dopamine index. In vitro release of prolactin from the ectopic gland was markedly decreased in animals treated with cyclosporine for 2 days and this effect was less evident in 8-day treated rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Thymostimulin effects on the pituitary-ovarian axis in hyperprolactinemic young female rats

This work was undertaken to study the effects of thymostimulin on the pituitary-ovarian axis of young female rats, and to elucidate possible prolactin-mediated effects. 30-day-old rats implanted with an ectopic pituitary from a littermate male donor under the kidney capsule or sham-operated animals were injected with thymostimulin or vehicle for 2 and 8 days. Chronic thymostimulin treatment to sham-operated rats increased plasma prolactin and estradiol levels, and decreased gonadotropin levels. Thymostimulin administration to pituitary-grafted rats did not further modify the increase in plasma prolactin and the decrease in plasma luteinizing hormone levels induced by the presence of an ectopic pituitary, suggesting a hypothalamic and/or hypophysial site of action of the thymic fraction. An increase in plasma estradiol and progesterone levels was observed with the in vivo thymostimulin treatment, although differential in vitro effects on estradiol responses to human chorionic gonadotropin in the various groups studied were observed. These effects seem to be mediated through the changes in plasma prolactin and gonadotropin concentrations observed. The above-mentioned changes induced by the thymic fraction on plasma estradiol and progesterone levels might counteract prolactin effects on the thymus. These data suggest that thymostimulin treatment of young female rats changes hypophysial and sex hormone secretion, as well as the response of the ovaries to human chorionic gonadotropin, probably modifying the normal process of sexual maturation.

Effects of naloxone on pulsatile luteinizing hormone in experimental hyperprolactinemia

It is well known that opioids regulate luteinizing hormone (LH) secretion through not fully understood mechanisms. This study describes the effects of naloxone on the episodic release of LH in adult sham-operated and pituitary-grafted female rats. Animals were rendered hyperprolactinemic by transplanting 2 pituitary glands beneath the kidney capsule. Naloxone (2 mg/kg/h) or saline (0.5 ml/h) were administered iv through jugular cannulae and subjects were bled at 7 min intervals for a period of 3 h. As expected, pituitary-grafting was followed by an increase in mean values of prolactin during the bleeding period. Naloxone administration decreased mean serum prolactin levels in sham-operated rats and did not further change them in pituitary-grafted animals. Hyperprolactinemia was associated with increases in mean serum LH levels during the bleeding period and in the absolute amplitude of LH peaks. Naloxone administration increased mean values of LH and the absolute amplitude of LH peaks, and decreased their frequency in sham-operated rats. Neither pituitary grafting nor naloxone administration modified the frequency, duration or relative amplitude of LH peaks. However, naloxone administration reduced the mean half-life of LH in sham-operated rats to a similar extent than did pituitary grafting. Naloxone failed to further change the mean half-life of LH in pituitary-grafted rats. These results suggest that opioids modulate the pulsatile pattern of LH and that these effects are blunted in pituitary-grafted animals.

Effects of chronic melatonin administration on adrenal medulla catecholamine metabolism in adult male golden hamsters

The role of melatonin on adrenal medullary function was evaluated in adult golden (Syrian) hamsters injected daily at either 0800 or 1600 with melatonin (25 micrograms/hamster) or vehicle (0.1% ethanol in saline). Sixty days after initiation of treatment and 16 or 24 hr after the last injection of melatonin, animals were killed by decapitation and blood and tissue collected. Plasma prolactin levels were reduced by chronic administration of melatonin only when animals were treated at 1600. Tyrosine hydroxylase (TH) activity in the adrenal medulla was not changed by either morning or afternoon administration of melatonin. Phenylethanolamine-N-methyl transferase (PNMT) was changed by afternoon administration of melatonin. Morning and afternoon melatonin injections led to the reduction of both adrenal monoamine oxidase (MAO) and catechol-O-methyl transferase (COMT) activities although the afternoon injections led to a greater magnitude of change. Norepinephrine and epinephrine contents were significantly reduced by morning melatonin administration but were not changed by afternoon administration of the hormone. These data suggest that melatonin has direct and possibly indirect effects on adrenal medullary function in the hamster. However, further studies will be required to characterize the effects of melatonin on catecholamine synthesis and release and the physiological significance of these effects.

Changes on protein expression associated with salinity tolerance in Brassica cell cultures

The synthesis of proteins from salt-tolerant Brassica oleracea L. var. botrytis L. subvar. cauliflora (Gars.) DC. (cauliflower) cell cultures is modified in relation to controls in several features. There are nine newly induced polypeptides in tolerant cultures (absent in control conditions). Some of them are only present under low salt levels (85 mM NaCl). Another group seems to be representative of moderate and high salt levels (170 and 255 mM NaCl), and a third group is present in all the salt conditions tested. On the other hand, the synthesis of most of the polypeptides present in control conditions is modified in salt-tolerant cultures by increasing, decreasing or stopping their synthesis in any of the tested conditions. The relationship between these changes in Brassica and other plant systems is discussed.

Serum prolactin and luteinizing hormone levels and the activities of hypothalamic monoamine oxidase A and B and phenylethanolamine-N-methyl transferase are changed during sexual maturation in male rats treated neonatally with melatonin

Male rat pups were given a single dose of melatonin on day 5 of age. On days 30, 45, and 60, prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T) were measured in serum and monoamine oxidase A (MAO A) activity, monoamine oxidase B (MAO B), and phenylethanolamine-N-methyl transferase (PNMT) activity were measured in the hypothalamus. Melatonin administration increased serum PRL levels at all ages studied. Serum LH levels were decreased in the melatonin treated group on day 30, but levels were elevated on days 45 and 60 of age as compared to controls. LH response to luteinizing hormone-releasing hormone (LHRH) only increased in melatonin treated animals at 30 days of age. Serum T levels decreased with melatonin treatment at 30 days of age, but increased on days 45 and 60 of age. T response to human chorionic gonadotropin (hCG) was blunted by melatonin treatment at 30 days of life. Hypothalamic MAO A activity increased, after neonatal melatonin administration, at 30 and 45 days of age and decreased at 60 days of life. Early neonatal melatonin administration increased MAO B and PNMT activities on day 45. These findings suggest that neonatal melatonin administration induces an earlier sexual maturation in male rats, possibly related to PRL, LH, MAO, and PNMT increases.

Persistence of a micrococcal nuclease sensitive region spanning the promoter-coding region junction of a cell cycle regulated human H4 histone gene throughout the cell cycle

We have examined the chromatin structure of the cell cycle regulated human H4 histone gene FO108A at various times during the cell cycle, by treating nuclei isolated from synchronized HeLa S3 cells with micrococcal nuclease. Purified DNA was fractionated electrophoretically, transferred to nitrocellulose, and hybridized to small (150-250 nucleotides) radiolabeled probes from various portions of the promoter and coding regions of the gene. Our results indicate the existence of a micrococcal nuclease sensitive region located between positions -60 and +90 base pairs (bp) from the start codon of the gene, which includes the TATA box. This nuclease-sensitive region persists at all the cell cycle times analyzed. Hybridization with a 250-bp probe containing only coding region sequences reveals a disrupted nucleosomal ladder during early S phase, when this H4 histone gene replicates and exhibits an enhanced level of transcription. By mid-S phase, the regular nucleosomal structure of the coding region is restored and persists during subsequent phases of the cell cycle. The disruption of a normal nucleosomal organization in the promoter and mRNA coding regions of this H4 histone gene is also supported by the sensitivity of these sequences to S1 nuclease.

Nucleosomal organization of a BPV minichromosome containing a human H4 histone gene

To address the relationship between chromatin structure and histone gene expression, the nucleosomal organization of a cell cycle-dependent human H4 histone gene in a bovine papilloma virus (BPV) minichromosome was examined. The nucleosome repeat length of the human H4 histone gene, maintained as a stable episome in a C127 mouse cell line designated I-8, was compared with that of the chromosomal copy of the H4 gene in human (HeLa) cells. In both cell lines, the H4 histone gene is predominantly expressed during the S phase of the cell cycle. The nucleosome repeat length of total HeLa cell and C127 mouse cell chromatin was similarly examined. Nuclei were digested with micrococcal nuclease and the DNA was fractionated electrophoretically, transferred to nitrocellulose filters and hybridized with radiolabelled (32P) cloned DNA probes. The nucleosome repeat length of the H4 gene, as an episome in the C127 mouse cell (153 +/- 8) and as an integrated copy in a HeLa cell (163 +/- 10) was considerably shorter than total genomic host cell (C127) (190 +/- 5) or HeLa cell chromatin (183 +/- 7). Our results indicate that the episomal H4 histone gene is packaged as chromatin. Moreover, the shortened nucleosome repeat length of the H4 gene, both as an episome or integrated chromosome sequence, suggests that the repeat length is characteristic of the gene and may be functionally related to its cell cycle regulated expression.

Reversible changes in the nucleosomal organization of a human H4 histone gene during the cell cycle

The organization of nucleosomes associated with a cell cycle regulated human H4 histone gene was examined in synchronized HeLa S3 cells. At various times during the cell cycle, nuclei were digested with micrococcal nuclease, and the nucleosomal pattern of the gene was obtained by Southern blot analysis using radiolabeled human histone H4 gene probes. We have detected reversible changes during the cell cycle in the chromatin structure of this gene, as reflected by the shortening of the nucleosomal spacing after replication and the peak of transcription. This variation is also observed when DNA and protein syntheses are inhibited. By using a probe that comprises 250 base pairs (bp) of the coding region and 240 bp of the 5' end of the gene, containing the promoter and DNase I sensitive sequences, we also have observed a general disruption of the nucleosomal organization, which is reflected by a degeneration of the characteristic nucleosomal ladder produced by micrococcal nuclease digestion. This modification coincides with the replication and active transcription of the gene (early S phase), which recovers its regular nucleosomal appearance when both processes have been completed, although the nucleosome linker length is shortened. When the probe utilized comprises the distal 3' end of the gene, there is no disruption of the nucleosomal pattern, but the linker region also exhibits a shortened length. A non-cell cycle regulated gene (beta-globin) does not exhibit such modifications in any of the situations analyzed.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell cycle-dependent expression of a stable episomal human histone gene in a mouse cell

We have constructed a recombinant plasmid that includes a cell cycle-dependent human H4 histone gene with 650 base pairs of 5' and 900 base pairs of 3' flanking sequences and the 69% transforming fragment of bovine papilloma virus. When transfected into C127 mouse cells, this plasmid is maintained as a stable episome with approximately 20 copies per cell. Micrococcal nuclease digestion indicates that the episomal human histone gene is packaged as chromatin. The human H4 histone transcript is initiated at the correct 5' start site and undergoes selective destabilization when DNA synthesis is inhibited. When C127 cells containing the episomal H4 histone gene are synchronized, the human H4 histone mRNA levels are regulated coordinately with DNA replication and parallel those of transcripts from the murine chromosomal H4 histone genes. Our results suggest that the regulatory sequences and/or regulatory molecules associated with murine and human histone genes are compatible. The human histone gene-bovine papillomavirus episome is therefore a viable system for studying cell cycle-regulated histone gene expression under conditions where control is not influenced at the site of chromosomal integration by cis-acting elements of genes normally not contiguous.

Structural studies on Allium cepa L. chromatin: enhanced stability of internucleosome interactions in plant chromatin

The pattern of micrococcal nuclease digestion of chromatin from different organs of Allium cepa has been studied. The DNA from small oligonucleosomes appears to be highly degraded and heterogeneous. In solutions of intermediate ionic strength (0.15 M NaCl) histones H2A and H2B form dimers, however at high salt concentrations (2 M NaCl) they tend to form complexes of higher order, such as tetramers. It is proposed that a correlation exists between the ability of these proteins to form tetramers and the particular stability of internucleosome interactions.

Increased replication in plant nuclei, whose spread chromatin contains enlarged nucleosomal linkers, is only partially due to a rise in the number of DNA elongating chains

Dormant and proliferating meristems of Allium cepa L. roots were compared. In vivo DNA synthesis was nine times higher in proliferating meristems, partially due to a 2.5 times increase in the relative number of DNA elongating chains, as estimated after the assay for 3H-TTP incorporation in permeabilized cells. Stereology done on conventional electronmicrographs showed that nucleoplasm was nearly three times larger in nuclei of proliferating meristems, while the amount of compact chromatin did not diminish but redistributed instead, resulting that the chromatin/nucleoplasm interface increased. Finally, the nucleosomal linker -as seen after the spreading of the chromatin fibres- was larger and more variable in proliferating than in dormant meristems.

[Myelocytic leukaemia with atypical evolution (author's transl)]

A case of myelocytic leukaemia appeared in a four year old boy. The surprisingly benign evolution until now, leds to a speculation on the possible influence exerced by chickenpox virus as a immunologic stimulant.