Immunolocalization of AQP5 in resting and stimulated normal labial glands and in Sjögren's syndrome

OBJECTIVE

In our current work, in vivo examination of AQP5 distribution in labial salivary glands following stimulation of secretion has been carried out in normal individuals and in patients with Sjögren's syndrome.

SUBJECTS AND METHODS

For this study, we selected five patients with primary Sjögren's syndrome (mean age 62.4 ± 10.6 s.d. years) diagnosed in accordance with the European Cooperative Community classification criteria. There were five patients (mean age 27 ± 2.5 s.d. years) in the control group. The subcellular distribution of AQP5 in human labial gland biopsies was determined with light and immunoelectron microscopy before and 30 min after administration of oral pilocarpine.

RESULTS

In unstimulated control and Sjögren's labial glands, AQP5 is about 90% localized in the apical plasma membrane, with only rarely associated gold particles with intracellular membrane structures. We have found no evidence of pilocarpine-induced changes in localization of AQP5 in either healthy individuals or patients with Sjögren's syndrome.

CONCLUSIONS

Our studies indicate that neither Sjögren's syndrome itself, nor muscarinic cholinergic stimulation in vivo caused any significant changes in the distribution of AQP5 in the labial salivary gland cells.

Systematic screening for PRKAR1A gene rearrangement in Carney complex: identification and functional characterization of a new in-frame deletion

BACKGROUND

Point mutations of the PRKAR1A gene are a genetic cause of Carney complex (CNC) and primary pigmented nodular adrenocortical disease (PPNAD), but in 30% of the patients no mutation is detected.

OBJECTIVE

Set up a routine-based technique for systematic detection of large deletions or duplications of this gene and functionally characterize these mutations.

METHODS

Multiplex ligation-dependent probe amplification (MLPA) of the 12 exons of the PRKAR1A gene was validated and used to detect large rearrangements in 13 typical CNC and 39 confirmed or putative PPNAD without any mutations of the gene. An in-frame deletion was characterized by western blot and bioluminescence resonant energy transfer technique for its interaction with the catalytic subunit.

RESULTS

MLPA allowed identification of exons 3-6 deletion in three patients of a family with typical CNC. The truncated protein is expressed, but rapidly degraded, and does not interact with the protein kinase A catalytic subunit.

CONCLUSIONS

MLPA is a powerful technique that may be used following the lack of mutations detected by direct sequencing in patients with bona fide CNC or PPNAD. We report here one such new deletion, as an example. However, these gene defects are not a frequent cause of CNC or PPNAD.

Meta-analysis: sequential therapy for Helicobacter pylori eradication in children

BACKGROUND

Problems with the standard triple treatment recommended for Helicobacter pylori eradication therapy include unsatisfactory (less than 80%) eradication rates among children.

AIM

To assess the evidence for sequential therapy compared with triple therapy on H. pylori eradication rates in children.

METHODS

The Cochrane Library, MEDLINE and EMBASE databases were searched in May 2012, with no language restrictions, as were abstracts from major gastroenterology conferences, for randomised controlled trials (RCTs) comparing sequential therapy with standard triple therapy for H. pylori eradication. Additional references were obtained from reviewed articles. Authors were contacted for extra information. Dichotomous data were pooled to obtain the relative risk (RR) of the eradication rate, with a 95% CI.

RESULTS

Ten RCTs involving a total of 857 children aged 3-18 years met the inclusion criteria. Of the 409 patients in the sequential therapy group, 318 (78%, 95% CI 73-82) experienced eradication compared with 314 of the 444 patients (71%, 95% CI 66-75) in the standard triple therapy group (RR 1.14, 95% CI 1.06-1.23, number needed to treat 15; fixed-effects model). Sequential therapy was superior to 7-day standard triple therapy, but was not significantly better than 10-day or 14-day triple therapy. There were no significant differences between groups in the risk of adverse effects.

CONCLUSIONS

The pooled evidence suggests that 10-day sequential therapy compared with standard triple therapy may be considered as an option for increasing the eradication rates in children; however, it is still less than desired.

PRKAR1A gene analysis and protein kinase A activity in endometrial tumors

PRKAR1A codes for the type 1a regulatory subunit (RIα) of the cAMP-dependent protein kinase A (PKA), an enzyme with an important role in cell cycle regulation and proliferation. PKA dysregulation has been found in various tumors, and PRKAR1A-inactivating mutations have been reported in mostly endocrine neoplasias. In this study, we investigated PKA activity and the PRKAR1A gene in normal and tumor endometrium. Specimens were collected from 31 patients with endometrial cancer. We used as controls 41 samples of endometrium that were collected from surrounding normal tissues or from women undergoing gynecological operations for other reasons. In all samples, we sequenced the PRKAR1A-coding sequence and studied PKA subunit expression; we also determined PKA activity and cAMP binding. PRKAR1A mutations were not found. However, PKA regulatory subunit protein levels, both RIα and those of regulatory subunit type 2b (RIIβ), were lower in tumor samples; cAMP binding was also lower in tumors compared with normal endometrium (P<0.01). Free PKA activity was higher in tumor samples compared with that of control tissue (P<0.01). There are significant PKA enzymatic abnormalities in tumors of the endometrium compared with surrounding normal tissue; as these were not due to PRKAR1A mutations, other mechanisms affecting PKA function ought to be explored.

Vitrification of bovine blastocysts pretreated with sublethal hydrostatic pressure stress: evaluation of post-thaw in vitro development and gene expression

Sublethal stress treatment has been reported to enhance gametes' performance in subsequent procedures, such as cryopreservation. The aim of the present study was to evaluate the effect of different equilibration times between the termination of a sublethal hydrostatic pressure (HP) stress treatment and the initiation of vitrification on the post-thaw survival, continued in vitro development, hatching rate and gene expression of selected candidate genes of in vitro-produced (IVP) expanded bovine blastocysts. Day 7 IVP blastocysts were subjected to 600 bar pressure for 60 min at 32°C. Immediately after pressure treatment (HP0h) or after 1 or 2h incubation (HP1h and HP2h groups, respectively), embryos were either vitrified and warmed using the open pulled straw method, followed by 72 h in vitro culture or were stored at -80°C until gene expression analysis. Re-expansion and hatching rates after vitrification-warming were significantly (P<0.05) higher in the HP0h (88 and 76%, respectively) and HP1h (90 and 75%, respectively) groups than in the untreated (82 and 63%, respectively) and HP2h groups (79 and 70%, respectively). Moreover, the HP1h group showed further improvement in the speed of re-expansion and resumption of normal in vitro development. Cumulative analysis of all genes (SC4MOL, HSP1A1A, SOD2 and GPX4) revealed a similar pattern of expression, with a tendency for peak transcript abundance 1h after HP treatment. Application of HP stress treatment was found to be efficient in increasing the in vitro developmental competence of vitrified bovine embryos.

Meta-analysis: Lactobacillus rhamnosus GG for abdominal pain-related functional gastrointestinal disorders in childhood

BACKGROUND

A lack of reliable treatments for abdominal pain-related functional gastrointestinal disorders prompts interest in new therapies.

AIM

To evaluate systematically the effect of Lactobacillus rhamnosus GG (LGG) for treating abdominal pain-related functional gastrointestinal disorders in children.

METHODS

MEDLINE, EMBASE, CINAHL, the Cochrane Library, trial registries and proceedings of major meetings were searched for randomised controlled trials (RCTs) evaluating LGG supplementation in children with abdominal pain-related functional gastrointestinal disorders based on the Rome II or Rome III criteria. Risk of bias was assessed for generation of the allocation sequence, allocation concealment, blinding and follow-up.

RESULTS

Compared with placebo, LGG supplementation was associated with a significantly higher rate of treatment responders (defined as no pain or a decrease in pain intensity) in the overall population with abdominal pain-related functional gastrointestinal disorders (three RCTs, n = 290; risk ratio, RR 1.31, 95% CI 1.08-1.59, number needed to treat, NNT 7, 95% CI 4-22) and in the irritable bowel syndrome (IBS) subgroup (three RCTs, n = 167; RR 1.70, 95% CI 1.27-2.27, NNT 4, 95% CI 3-8). However, no difference was found in the rate of treatment responders between children with functional abdominal pain or functional dyspepsia who received placebo or LGG. The intensity of pain was significantly reduced in the overall study population and in the IBS subgroup. The frequency of pain was significantly reduced in the IBS subgroup only.

CONCLUSION

The use of Lactobacillus rhamnosus GG moderately increases treatment success in children with abdominal pain-related functional gastrointestinal disorders, particularly among children with IBS.

The role of germline AIP, MEN1, PRKAR1A, CDKN1B and CDKN2C mutations in causing pituitary adenomas in a large cohort of children, adolescents, and patients with genetic syndromes

The prevalence of germline mutations in MEN1, AIP, PRKAR1A, CDKN1B and CDKN2CI is unknown among pediatric patients with pituitary adenomas (PA). In this study, we screened children with PA for mutations in these genes; somatic GNAS mutations were also studied in a limited number of growth hormone (GH) or prolactin (PRL)-secreting PA. We studied 74 and 6 patients with either isolated Cushing disease (CD) or GH- or PRL-secreting PA, respectively. We also screened four pediatric patients with CD, and four with GH/PRL-secreting tumors who had some syndromic features. There was one AIP mutation (p.Lys103Arg) among 74 CD patients. Two MEN1 mutations that occurred in patients with recurrent or difficult-to-treat disease were found among patients with CD. There was one MEN1 and three AIP mutations (p.Gln307ProfsX104, p.Pro114fsX, p.Lys241X) among pediatric patients with isolated GH- or PRL-secreting PA and one additional MEN1 mutation in a patient with positive family history. There were no mutations in the PRKAR1A, CDKN1B, CDKN2C or GNAS genes. Thus, germline AIP or MEN1 gene mutations are frequent among pediatric patients with GH- or PRL-secreting PA but are significantly rarer in pediatric CD; PRKAR1A mutations are not present in PA outside of Carney complex.

Meta-analysis: the effects of Saccharomyces boulardii supplementation on Helicobacter pylori eradication rates and side effects during treatment

BACKGROUND

Problems with currently recommended Helicobacter pylori eradication therapies include unsatisfactory eradication rates and/or therapy-associated side effects.

AIM

To investigate the effects of Saccharomyces boulardii as supplementation to standard triple therapy on H. pylori eradication rates and therapy-associated side effects.

METHODS

The Cochrane Library, MEDLINE and EMBASE databases were searched in July 2010, with no language restrictions, for randomized controlled trials (RCTs); additional references were obtained from reviewed articles.

RESULTS

Five RCTs involving a total of 1307 participants (among them only 90 children) met the inclusion criteria. Compared with placebo or no intervention, S. boulardii given along with triple therapy significantly increased the eradication rate [four RCTs, n = 915, relative risk (RR) 1.13, 95% confidence interval (CI) 1.05-1.21] and reduced the risk of overall H. pylori therapy-related adverse effects (five RCTs, n = 1305, RR 0.46, 95% CI 0.3-0.7), particularly of diarrhoea (four RCTs, n = 1215, RR 0.47, 95% CI 0.32-0.69). There were no significant differences between groups in the risk of other adverse effects.

CONCLUSION

In patients with H. pylori infection, there is evidence to recommend the use of S. boulardii along with standard triple therapy as an option for increasing the eradication rates and decreasing overall therapy-related side effects, particularly diarrhoea.

Meta-analysis: the effects of Saccharomyces boulardii supplementation on Helicobacter pylori eradication rates and side effects during treatment

BACKGROUND

Problems with currently recommended Helicobacter pylori eradication therapies include unsatisfactory eradication rates and/or therapy-associated side effects.

AIM

To investigate the effects of Saccharomyces boulardii as supplementation to standard triple therapy on H. pylori eradication rates and therapy-associated side effects.

METHODS

The Cochrane Library, MEDLINE and EMBASE databases were searched in July 2010, with no language restrictions, for randomized controlled trials (RCTs); additional references were obtained from reviewed articles.

RESULTS

Five RCTs involving a total of 1307 participants (among them only 90 children) met the inclusion criteria. Compared with placebo or no intervention, S. boulardii given along with triple therapy significantly increased the eradication rate [four RCTs, n = 915, relative risk (RR) 1.13, 95% confidence interval (CI) 1.05-1.21] and reduced the risk of overall H. pylori therapy-related adverse effects (five RCTs, n = 1305, RR 0.46, 95% CI 0.3-0.7), particularly of diarrhoea (four RCTs, n = 1215, RR 0.47, 95% CI 0.32-0.69). There were no significant differences between groups in the risk of other adverse effects.

CONCLUSION

In patients with H. pylori infection, there is evidence to recommend the use of S. boulardii along with standard triple therapy as an option for increasing the eradication rates and decreasing overall therapy-related side effects, particularly diarrhoea.

Are treatment targets for hypercholesterolemia evidence based? Systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

Search for evidence supporting target age, level of intervention and target values for low-density lipoprotein (LDL) cholesterol levels in children with familial hypercholesterolemia.

DESIGN

Systematic review and meta-analysis. PubMed, Medline, CINAHL and Cochrane Reviews databases from 1966 to 2007 were searched for articles reporting statin therapy in children and adolescents aged 8-18 years. Retrieved articles were screened for double-blind randomised controlled trials (RCTs).

RESULTS

Seven trials involving 884 patients met inclusion criteria. Meta-analysis findings showed significantly reduced total cholesterol, LDL cholesterol and apolipoprotein B, whereas high-density lipoprotein cholesterol and apolipoprotein A1 were significantly increased by statin therapy. Evidence on target level in children was limited to one study attainment of LDL cholesterol treatment target in 60% of the subjects in the treatment group and none in the placebo group reached their target LDL cholesterol. Evidence on the effect of statins on surrogate markers of atherosclerosis was limited to two studies (one RCT on the effect upon the carotid intima-media thickness (n=211; mean difference (MD) -0.01; 95% CI -0.03 to -0.00), and one showing that the mean absolute change in flow-mediated dilation after 28 weeks of statin treatment was significantly higher in the simvastatin group compared to placebo group (MD 2.7%; 95% CI 0.42 to 4.98).

CONCLUSIONS

There is no firm evidence regarding when to start statin treatment or what target LDL cholesterol level should be attained. Recent recommendations that favour statins as the first-line drug treatment for hypercholesterolemia are evidence based. Studying high-risk groups (obese or diabetic patients) and incorporating composite end points may help define treatment guidelines.

Quantitative differences in antibiotic resistance between methicillin-resistant and methicillin-susceptible Staphylococcus aureus strains isolated in Hungary, Austria and Macedonia

The aim of this study was to compare the quantitative susceptibility of methicillin-resistant and -susceptible Staphylococcus aureus (MRSA and MSSA) strains from three European countries to nine antistaphylococcal agents. The antibiotic susceptibility of 274 MRSA and 284 MSSA strains from Hungary, Austria and macedonia was tested by the broth microdilution method. The clonal relationship of strains was determined by pulsed-field gel electrophoresis. Intermediate susceptibility to vancomycin appeared in Macedonian MRSA strains. Macedonian MRSA strains had high-level amikacin and gentamicin resistance. MSSA strains generally were susceptible to all drugs at minimum inhibitory concentrations (MIC(50)) except for gentamicin resistance in Macedonian strains. In Hungary and Austria a common antibiotic resistance phenotype of MRSA predominated, while in macedonia three other phenotypes were also prevalent. Geographical differences in the resistance of S. aureus are still high. Since resistance levels of MRSA and MSSA strains differ extensively, they should be considered separately for antibiotic resistance analysis.

An Intronic mutation is associated with prolactinoma in a young boy, decreased penetrance in his large family, and variable effects on MEN1 mRNA and protein

Prolactinomas are rare tumors in prepubertal children. A prolactinoma in a young child may be due to sequence variants in genes that are known to cause these tumors ( MEN1, PRKAR1A, AIP). An 11-year-old boy with a macroprolactinoma was treated with cabergoline and the tumor receded. We studied the patient and his family for genetic causes of this tumor. No mutations were present in the coding sequence of PRKAR1A and AIP. A novel heterozygous substitution (IVS3-7 c>a) was identified in intron 3 of MEN1. We also found an additional PCR amplicon that incorporated the entire intron 3 of the gene (210 bp) in the patient's cDNA. The same amplicon was present with lower intensity in some of the control individuals who were not mutation carriers. Intron 3 harbors an in-frame stop codon and its incorporation is predicted to result in a prematurely terminated protein. We conclude that a novel MEN1 variation was identified in a young boy with prolactinoma and six of his relatives who did not present with prolactinoma or other MEN1 related symptoms. This novel MEN1 variation may be associated with low penetrance of the disease. The IVS3-7 c>a defect is suggested to be pathogenic because it is associated with lower menin levels in the cells of these patients, but its consequences may be mitigated by a variety of factors including changes in transcription and translation of the MEN1 gene.

Protein kinase A subunit expression is altered in Bloom syndrome fibroblasts and the BLM protein is increased in adrenocortical hyperplasias: inverse findings for BLM and PRKAR1A

Bloom syndrome is a genetic disorder associated with chromosomal instability and a predisposition to tumors that is caused by germline mutations of the BLM gene, a RecQ helicase. Benign adrenocortical tumors display a degree of chromosomal instability that is more significant than benign tumors of other tissues. Cortisol-producing hyperplasias, such as primary pigmented nodular adrenocortical disease (PPNAD), which has been associated with protein kinase A (PKA) abnormalities and/or PRKAR1A mutations, also show genomic instability. Another RecQ helicase, WRN, directly interacts with the PRKAR1B subunit of PKA. In this study, we have investigated the PRKAR1A expression in primary human Bloom syndrome cell lines with known BLM mutations and examined the BLM gene expression in PPNAD and other adrenal tumor tissues. PRKAR1A and other protein kinase A (PKA) subunits were expressed in Bloom syndrome cells and their level of expression differed by subunit and cell type. Overall, fibroblasts exhibited a significant decrease in protein expression of all PKA subunits except for PRKAR1A, a pattern that has been associated with neoplastic transformation in several cell types. The BLM protein was upregulated in PPNAD and other hyperplasias, compared to samples from normal adrenals and normal cortex, as well as samples from cortisol- and aldosterone-producing adenomas (in which BLM was largely absent). These data reveal an inverse relationship between BLM and PRKAR1A: BLM deficiency is associated with a relative excess of PRKAR1A in fibroblasts compared to other PKA subunits; and PRKAR1A deficiency is associated with increased BLM protein in adrenal hyperplasias.

Phosphodiesterase 11A expression in the adrenal cortex, primary pigmented nodular adrenocortical disease, and other corticotropin-independent lesions

A variety of adrenal tumors and bilateral adrenocortical hyperplasias (BAH) leading to Cushing syndrome (CS) may be caused by aberrant cAMP signaling. We recently identified patients with a micronodular form of BAH that we have called "isolated micronodular adrenocortical disease" (iMAD) in whom CS was associated with inactivating mutations in phosphodiesterase (PDE) 11A ( PDE11A). In the present study, we examined PDE11A expression in normal adrenocortical tissue, sporadic tumors, and hyperplasias without PDE11A mutations, and primary pigmented nodular adrenocortical disease (PPNAD) and adenomas from patients with PRKAR1A and a single tumor with a GNAS mutation. The total number of the tumor samples that we studied was 22. Normal human tissues showed consistent PDE11A expression. There was variable expression of PDE11A in sporadic adrenocortical hyperplasia or adenomas; PPNAD tissues from patients with PRKAR1A mutations expressed consistently high levels of PDE11A in contrast to adenomas caused by GNAS mutations. Phosphorylated CREB was the highest in tissues from patients with iMAD compared to all other forms of BAH and normal adrenal tissue. We conclude that PDE11A is expressed widely in adrenal cortex. Its expression appears to be increased in PPNAD but varies widely among other adrenocortical tumors. PRKAR1A expression appears to be higher in tissues with PDE11A defects. Finally, sequencing defects in PDE11A are associated with a high state of CREB phosphorylation, just like PRKAR1A mutations. These preliminary data suggest that these two molecules are perhaps regulated in a reverse manner in their control of cAMP signaling in adrenocortical tissues.

How the new tools to analyze the human genome are opening new perspectives: the use of gene expression in investigations of the adrenal cortex

With the promise of state-of-the-art molecular technologies and the tools provided by the human genome project, a number of investigators are trying to identify molecular targets of adrenocortical tumorigenesis. One path in this endeavor was the identification by positional cloning of genes that are mutated in rare adrenocortical tumors. The subject of this article is an update of the results of experiments in the second path that was followed by us and others: that of using genome-wide expression analysis of adrenocortical cells in normal and various disease states. Transcriptomic analysis is a rapidly evolving technology; this article summarizes some data on the adrenal cortex and points out how these new technologies can be used in the identification of important genes and molecular pathways in both normal and diseased adrenal cortex.

Male infertility as a component of Carney complex

Carney complex (CNC) is a multiple neoplasia syndrome characterised by endocrine tumours, spotty skin pigmentation, cardiac and other myxomas, psamommatous and pigmented schwannomas, large cell calcifying Sertoli cell tumours, and mammary ductal adenomas and other more rare lesions. CNC is inherited in an autosomal-dominant manner and has been mapped to at least two chromosomal loci. Patients who map to the CNC1 locus located on chromosome 17 carry inactivating mutations of the PRKAR1A gene that encodes the cAMP-dependent protein kinase regulatory subunit type 1-alpha (Kirschner et al., 2000). One gene responsible for type 2 (CNC2) is located on chromosome 2p16. Infertility in CNC can be caused by a number of factors; there is evidence that prkar1a deficiency in mice leads directly to infertility (Burton et al., 2006), but patients with CNC also have Sertoli cell tumours and a number of other reasons to affect fertility. We report on an infertile male with CNC and present evidence that male infertility should be considered as part of the phenotype of CNC.

Meta-analysis: enteral nutrition in active Crohn's disease in children

BACKGROUND

Controversy exists surrounding the optimal treatment for inducing remission in active Crohn's disease.

AIM

To review and update evidence on the effectiveness of enteral nutrition (EN) in treating active Crohn's disease in children.

METHODS

MEDLINE, EMBASE and The Cochrane Library (up to February 2007) were searched for randomized controlled trials (RCTs) relevant to Crohn's disease and EN in children.

RESULTS

We included 11 RCTs (n = 394). Seven RCTs (n = 204) compared EN with corticosteroid therapy. On the basis of pooled results of four RCTs (n = 144), we found no significant difference in the remission rates between groups (relative risk, RR 0.97, 95% CI 0.7-1.4, random effect model). Four RCTs (n = 190) compared two EN regimens. One of the four RCTs (n = 50) revealed a significant increase in the percentage of patients achieving remission in the total EN group compared with the partial EN group (RR 2.7, 95% CI 1-7.4). Because of lack of data, formal pooling of results was not possible for many outcomes (e.g., time until remission, duration of remission, growth data).

CONCLUSIONS

Limited data suggest similar efficacy for EN and corticosteroids. As the number of patients needed to provide a definite answer is too large, future studies should focus on detailed outcome measurements including growth and quality of life.