Cloning of a gene highly overexpressed in cancer coding for a novel KH-domain containing protein

In a previous large scale screen for differentially expressed genes in pancreatic cancer, we identified a gene highly overexpressed in cancer encoding a novel protein with four K-homologous (KH) domains. KH-domains are found in a subset of RNA-binding proteins, including pre-mRNA-binding (hnRNP) K protein and the fragile X mental retardation gene product (FMR1). By fluorescence in situ hybridization (FISH) the identified gene named koc (KH domain containing protein overexpressed in cancer) was assigned to chromosome 7p11.5. Two pseudogenes were localised on chromosome 6 and 11. The cloned koc cDNA has a 250 bp 5'-UTR, a 1740 bp ORF and a 2168 bp 3'-UTR. The AU-rich 3'-untranslated region of koc contains eight AUUUA and four AUUUUUA reiterated motifs. The deduced koc protein with 580 amino-acids has a relative molecular mass (Mr) of approximately 65,000 (65 K). The koc transcript is highly overexpressed in pancreatic cancer cell lines and in pancreatic cancer tissue as compared to both, normal pancreas and chronic pancreatitis tissue. High levels of expression were as well found in tissue samples of other human tumours. As the KH domain has been shown to be involved in the regulation of RNA synthesis and metabolism, we speculate that koc may assume a role in the regulation of tumour cell proliferation by interfering with transcriptional and or posttranscriptional processes. However, the precise role of koc in human tumour cells is unknown and remains to be elucidated.

Control of SIV rebound through structured treatment interruptions during early infection

In a randomized controlled trial with acute simian immunodeficiency virus (SIV)-infected macaques, both highly active antiretroviral therapy (HAART) and HAART with fixed-schedule structured treatment interruption (STI-HAART; alternating 3 weeks on and 3 weeks off therapy) suppressed viral load. In the STI-HAART group, T cell virus-specific immune response (VIR) and control of viral rebound increased concurrently during subsequent interruptions. In contrast, VIR did not increase and SIV rebounded after permanent treatment withdrawal in all animals on continuous HAART. Fixed-schedule STI-HAART appears to be an effective alternative to continuous HAART for the early treatment of retroviral infection.

Saliva as a Candidate for COVID-19 Diagnostic Testing: A Meta-Analysis

Background: COVID-19 is a serious and potentially deadly disease. Early diagnosis of infected individuals will play an important role in stopping its further escalation. The present gold standard for sampling is the nasopharyngeal swab method. However, several recent papers suggested that saliva-based testing is a promising alternative that could simplify and accelerate COVID-19 diagnosis. Objectives: Our aim was to conduct a meta-analysis on the reliability and consistency of SARS-CoV-2 viral RNA detection in saliva specimens. Methods: We have reported our meta-analysis according to the Cochrane Handbook. We searched the Cochrane Library, Embase, Pubmed, Scopus, Web of Science and clinical trial registries for eligible studies published between 1 January and 25 April 2020. The number of positive tests and the total number of tests conducted were collected as raw data. The proportion of positive tests in the pooled data were calculated by score confidence-interval estimation with the Freeman-Tukey transformation. Heterogeneity was assessed using the I 2 measure and the χ2-test. Results: The systematic search revealed 96 records after removal of duplicates. Twenty-six records were included for qualitative analysis and 5 records for quantitative synthesis. We found 91% (CI 80-99%) sensitivity for saliva tests and 98% (CI 89-100%) sensitivity for nasopharyngeal swab (NPS) tests in previously confirmed COVID-19 patients, with moderate heterogeneity among the studies. Additionally, we identified 18 registered, ongoing clinical trials of saliva-based tests for detection of the virus. Conclusion: Saliva tests offer a promising alternative to NPS for COVID-19 diagnosis. However, further diagnostic accuracy studies are needed to improve their specificity and sensitivity.

Simultaneous PKC and cAMP activation induces differentiation of human dental pulp stem cells into functionally active neurons

The plasticity of dental pulp stem cells (DPSCs) has been demonstrated by several studies showing that they appear to self-maintain through several passages, giving rise to a variety of cells. The aim of the present study was to differentiate DPSCs to mature neuronal cells showing functional evidence of voltage gated ion channel activities in vitro. First, DPSC cultures were seeded on poly-l-lysine coated surfaces and pretreated for 48h with a medium containing basic fibroblast growth factor and the demethylating agent 5-azacytidine. Then neural induction was performed by the simultaneous activation of protein kinase C and the cyclic adenosine monophosphate pathway. Finally, maturation of the induced cells was achieved by continuous treatment with neurotrophin-3, dibutyryl cyclic AMP, and other supplementary components. Non-induced DPSCs already expressed vimentin, nestin, N-tubulin, neurogenin-2 and neurofilament-M. The inductive treatment resulted in decreased vimentin, nestin, N-tubulin and increased neurogenin-2, neuron-specific enolase, neurofilament-M and glial fibrillary acidic protein expression. By the end of the maturation period, all investigated genes were expressed at higher levels than in undifferentiated controls except vimentin and nestin. Patch clamp analysis revealed the functional activity of both voltage-dependent sodium and potassium channels in the differentiated cells. Our results demonstrate that although most surviving cells show neuronal morphology and express neuronal markers, there is a functional heterogeneity among the differentiated cells obtained by the in vitro differentiation protocol described herein. Nevertheless, this study clearly indicates that the dental pulp contains a cell population that is capable of neural commitment by our three step neuroinductive protocol.

Distribution of aquaporin water channels AQP1 and AQP5 in the ductal system of the human pancreas

BACKGROUND

The exocrine pancreas secretes large volumes of isotonic fluid, most of which originates from the ductal system. The role of aquaporin (AQP) water channels in this process is unknown.

METHODS

Expression and localisation of known AQP isoforms was examined in normal human pancreas, pancreatic adenocarcinoma, and pancreatic cell lines of ductal origin (Capan-1, Capan-2, and HPAF) using reverse transcriptase-polymerase chain reaction and immunohistochemistry.

RESULTS

Messenger RNAs for AQP1, -3, -4, -5, and -8 were detected in normal pancreas and in pancreatic adenocarcinoma. The cell lines expressed AQP3, -4, and -5 but lacked AQP1 and AQP8. Immunohistochemistry of normal pancreas revealed that AQP1 is strongly expressed in centroacinar cells and in both the apical and basolateral domains of intercalated and intralobular duct epithelia. AQP1 expression declined with distance along the small interlobular ducts and was not detectable in larger interlobular ducts. AQP3 and AQP4 were not detectable by immunohistochemistry. AQP5 was observed at the apical membrane of intercalated duct cells and also in duct associated mucoid glands. AQP8 was confined to the apical pole of acinar cells. Both AQP1 and AQP5 were colocalised with cystic fibrosis transmembrane conductance regulator (CFTR) at the apical membrane of intercalated duct cells.

CONCLUSIONS

AQP1 and AQP5 are strongly expressed in the intercalated ducts of the human pancreas. Their distribution correlates closely with that of CFTR, a marker of ductal electrolyte secretion. This suggests that fluid secretion is concentrated in the terminal branches of the ductal tree and that both AQP1 and AQP5 may play a significant role.

Identification and localization of aquaporin water channels in human salivary glands

Aquaporin (AQP) water channels are expressed in a variety of fluid-transporting epithelia and are likely to play a significant role in salivary secretion. Our aim was to identify and localize the aquaporins expressed in human salivary glands. Total RNA was extracted from human parotid, submandibular, sublingual, and labial glands and from human brain. Expression of aquaporin mRNA was assessed by RT-PCR using specific primers for human AQP1, AQP3, AQP4, and AQP5. All four aquaporins were detected by RT-PCR in all of the glands, and the sequences were confirmed after further amplification with nested primers. Cleaned PCR products were then used as (32)P-labeled cDNA probes in a semiquantitative Northern blot analysis using glyceraldehyde-3-phosphate dehydrogenase as reference. Only AQP1, AQP3, and AQP5 mRNAs were present at significant levels. AQP localization was determined by immunohistochemistry on paraffin sections using affinity-purified primary antibodies and peroxidase-linked secondary antibodies. Each salivary gland type showed a broadly similar staining pattern: AQP1 was localized to the capillary endothelium and myoepithelial cells; AQP3 was present in the basolateral membranes of both mucous and serous acinar cells; AQP4 was not detected; and AQP5 was expressed in the luminal and canalicular membranes of both types of acinar cell. We conclude that AQP3 and AQP5 together may provide a pathway for transcellular osmotic water flow in the formation of the primary saliva.

Effect of Saccharomyces cerevisiae fermentation product on ruminal fermentation and nutrient utilization in dairy cows

The goal of this experiment was to investigate the effect of yeast culture (Saccharomyces cerevisiae) on rumen fermentation, nutrient utilization, and ammonia and methane emission from manure in dairy cows. Eight ruminally cannulated Holstein cows were allocated to 2 dietary treatments in a crossover design. Treatments were control (no yeast culture) and XP (yeast culture, fed at 56 g/head per day; XP, Diamond V Mills Inc., Cedar Rapids, IA). Dry matter intake, milk yield, milk composition, and body weight were similar between treatments. Milk urea nitrogen concentration was also not affected by treatment. Rumen pH was similar between the control and XP treatments, but rumen ammonia concentration tended to be lower with XP than with the control. Treatment had no effect on concentrations of total or individual volatile fatty acids, protozoal counts, polysaccharide-degrading activities (except amylase activity that tended to be increased by XP), or methane production in the rumen. Urinary N losses did not differ significantly between treatments, but allantoin and total purine derivative excretions and the estimated microbial N outflow from the rumen tended to be increased by XP compared with the control treatment. Total-tract apparent digestibility of dietary nutrients was not affected by XP. Milk fatty acid composition was also not altered by XP supplementation. Cumulative (253 h) ammonia and methane emissions from manure, measured in a steady-state gas emission system, were slightly decreased by XP. Overall, the yeast culture tested had little effect on ruminal fermentation, digestibility, or N losses, but tended to reduce rumen ammonia concentration and increase microbial protein synthesis in the rumen, and decreased ammonia and methane emissions from manure.

Effects of selective cholecystokinin antagonists L364,718 and L365,260 on food intake in rats

The selective type A and B cholecystokinin (CCK) receptor antagonists L364,718 and L365,260 were used to identify the receptor subtype that mediates the satiety effect of endogenous CCK. Male rats (n = 12-13/group), fed ground rat chow ad lib, received L364,718 (0, 1, 10, 100, or 1000 micrograms/kg IP) or L365,260 (0, 0.1, 1, 10, 100, 1000, or 10,000 micrograms/kg IP) 2 h after lights off, and food intake was measured 1.5, 3.5, and 5.5 h later. L364,718 significantly stimulated 1.5-h food intake by more than 40% at 10 micrograms/kg and higher doses; cumulative intake at 3.5 and 5.5 h remained elevated by about 20% at 1000 and 100 micrograms/kg of L364,718, respectively. In contrast, L365,260 had no significant stimulatory effect on feeding at any dose. The potency of L365,260 for antagonizing gastrin-stimulated gastric acid secretion was examined in unanesthetized rats. Male rats (n = 14), prepared with gastric and jugular vein cannulas, received doubling doses of gastrin (G-171) (0.16-5 nmol/kg/h IV), each dose for 30 min, and gastric juice was collected for each 30-min period. G-171 stimulated gastric acid output dose dependently; the minimal effective dose was 0.16 nmol/kg/h, while maximal output (5-fold above basal) occurred at 5 nmol/kg/h. L365,260 (0, 1, 10, 100, 1000, or 10,000 micrograms/kg IV), administered 30 min before continuous infusion of G-171 (1.25 or 5 nmol/kg/h), significantly inhibited acid output only at 10,000 micrograms/kg; cumulative 60-min output was decreased by 60%. These results suggest that CCK acts at CCK-A receptors to produce satiety during the dark period in ad lib-feeding rats.

Extracellular calcium sensing receptor in human pancreatic cells

BACKGROUND AND AIMS

The extracellular calcium sensing receptor (CaR) plays a key role in the calcium homeostatic system and is therefore widely expressed in tissues involved in calcium metabolism. However, the CaR has also been identified in other tissues where its role is less clear. We have investigated the presence of the CaR in the human pancreas.

METHODS

Messenger RNA for the CaR was detected by reverse transcription-polymerase chain reaction and the protein was localised by immunostaining. CaR function was assayed in Capan-1 cells by measuring intracellular calcium and [(3)H] thymidine incorporation.

RESULTS

The receptor was highly expressed in human pancreatic ducts. It was also expressed in exocrine acinar cells, in islets of Langerhans, and in intrapancreatic nerves and blood vessels. The CaR was expressed in both normal and neoplastic human tissue samples but was detected in only one of five ductal adenocarcinoma cells lines examined. Experiments on the CaR expressing adenocarcinoma cell line Capan-1 showed that the CaR was functional and was linked to mobilisation of intracellular calcium. Stimulation of the CaR reduced Capan-1 cell proliferation.

CONCLUSIONS

We propose that the CaR may play multiple functional roles in the human pancreas. In particular, the CaR on the duct luminal membrane may monitor and regulate the Ca(2+) concentration in pancreatic juice by triggering ductal electrolyte and fluid secretion. This could help to prevent precipitation of calcium salts in the duct lumen. The CaR may also help to regulate the proliferation of pancreatic ductal cells.

Integration of neuronally predifferentiated human dental pulp stem cells into rat brain in vivo

Pluripotency and their neural crest origin make dental pulp stem cells (DPSCs) an attractive donor source for neuronal cell replacement. Despite recent encouraging results in this field, little is known about the integration of transplanted DPSC derived neuronal pecursors into the central nervous system. To address this issue, neuronally predifferentiated DPSCs, labeled with a vital cell dye Vybrant DiD were introduced into postnatal rat brain. DPSCs were transplanted into the cerebrospinal fluid of 3-day-old male Wistar rats. Cortical lesion was induced by touching a cold (-60°C) metal stamp to the calvaria over the forelimb motor cortex. Four weeks later cell localization was detected by fluorescent microscopy and neuronal cell markers were studied by immunohistochemistry. To investigate electrophysiological properties of engrafted, fluorescently labeled DPSCs, 300 μm-thick horizontal brain slices were prepared and the presence of voltage-dependent sodium and potassium channels were recorded by patch clamping. Predifferentiated donor DPSCs injected into the cerebrospinal fluid of newborn rats migrated as single cells into a variety of brain regions. Most of the cells were localized in the normal neural progenitor zones of the brain, the subventricular zone (SVZ), subgranular zone (SGZ) and subcallosal zone (SCZ). Immunohistochemical analysis revealed that transplanted DPSCs expressed the early neuronal marker N-tubulin, the neuronal specific intermediate filament protein NF-M, the postmitotic neuronal marker NeuN, and glial GFAP. Moreover, the cells displayed TTX sensitive voltage dependent (VD) sodium currents (I(Na)) and TEA sensitive delayed rectifier potassium currents (K(DR)). Four weeks after injury, fluorescently labeled cells were detected in the lesioned cortex. Neurospecific marker expression was increased in DPSCs found in the area of the cortical lesions compared to that in fluorescent cells of uninjured brain. TTX sensitive VD sodium currents and TEA sensitive K(DR) significantly increased in labeled cells of the cortically injured area. In conclusion, our data demonstrate that engrafted DPSC-derived cells integrate into the host brain and show neuronal properties not only by expressing neuron-specific markers but also by exhibiting voltage dependent sodium and potassium channels. This proof of concept study reveals that predifferentiated hDPSCs may serve as useful sources of neuro- and gliogenesis in vivo, especially when the brain is injured.

New therapeutic targets in ulcerative colitis: the importance of ion transporters in the human colon

BACKGROUND

The absorption of water and ions (especially Na(+) and Cl(-)) is an important function of colonic epithelial cells in both physiological and pathophysiological conditions. Despite the comprehensive animal studies, there are only scarce available data on the ion transporter activities of the normal and inflamed human colon.

METHODS

In this study, 128 healthy controls and 69 patients suffering from ulcerative colitis (UC) were involved. We investigated the expressional and functional characteristics of the Na(+)/H(+) exchangers (NHE) 1-3, the epithelial sodium channel (ENaC), and the SLC26A3 Cl(-)/HCO 3- exchanger downregulated in adenoma (DRA) in primary colonic crypts isolated from human biopsy and surgical samples using microfluorometry, patch clamp, and real-time reverse-transcription polymerase chain reaction (RT-PCR) techniques.

RESULTS

Data collected from colonic crypts showed that the activities of electroneutral (via NHE3) and the electrogenic Na(+) absorption (via ENaC) are in inverse ratio to each other in the proximal and distal colon. We found no significant differences in the activity of NHE2 in different segments of the colon. Surface cell Cl(-)/HCO 3- exchange is more active in the distal part of the colon. Importantly, both sodium and chloride absorptions are damaged in UC, whereas NHE1, which has been shown to promote immune response, is upregulated by 6-fold.

CONCLUSIONS

These results open up new therapeutic targets in UC.

Biodegradation and Osteosarcoma Cell Cultivation on Poly(aspartic acid) Based Hydrogels

Development of novel biodegradable and biocompatible scaffold materials with optimal characteristics is important for both preclinical and clinical applications. The aim of the present study was to analyze the biodegradability of poly(aspartic acid)-based hydrogels, and to test their usability as scaffolds for MG-63 osteoblast-like cells. Poly(aspartic acid) was fabricated from poly(succinimide) and hydrogels were prepared using natural amines as cross-linkers (diaminobutane and cystamine). Disulfide bridges were cleaved to thiol groups and the polymer backbone was further modified with RGD sequence. Biodegradability of the hydrogels was evaluated by experiments on the base of enzymes and cell culture medium. Poly(aspartic acid) hydrogels possessing only disulfide bridges as cross-links proved to be degradable by collagenase I. The MG-63 cells showed healthy, fibroblast-like morphology on the double cross-linked and RGD modified hydrogels. Thiolated poly(aspartic acid) based hydrogels provide ideal conditions for adhesion, survival, proliferation, and migration of osteoblast-like cells. The highest viability was found on the thiolated PASP gels while the RGD motif had influence on compacted cluster formation of the cells. These biodegradable and biocompatible poly(aspartic acid)-based hydrogels are promising scaffolds for cell cultivation.

Involvement of endogenous CCK and CCK1 receptors in colonic motor function

Cholecystokinin (CCK) is a brain-gut peptide; it functions both as a neuropeptide and as a gut hormone. Although the pancreas and the gallbladder were long thought to be the principal peripheral targets of CCK, CCK receptors are found throughout the gut. It is likely that CCK has a physiological role not only in the stimulation of pancreatic and biliary secretions but also in the regulation of gastrointestinal motility. The motor effects of CCK include postprandial inhibition of gastric emptying and inhibition of colonic transit. It is now evident that at least two different receptors, CCK(1) and CCK(2) (formerly CCK-A and CCK-B, respectively), mediate the actions of CCK. Both localization and functional studies suggest that the motor effects of CCK are mediated by CCK(1) receptors in humans. Since CCK is involved in sensory and motor responses to distension in the intestinal tract, it may contribute to the symptoms of constipation, bloating and abdominal pain that are often characteristic of functional gastrointestinal disorders in general and irritable bowel syndrome (IBS), in particular. CCK(1) receptor antagonists are therefore currently under development for the treatment of constipation-predominant IBS. Clinical studies suggest that CCK(1) receptor antagonists are effective facilitators of gastric emptying and inhibitors of gallbladder contraction and can accelerate colonic transit time in healthy volunteers and patients with IBS. These drugs are therefore potentially of great value in the treatment of motility disorders such as constipation and constipation-predominant IBS.

N-Methyl-D-aspartate receptor antagonism decreases motility and inflammatory activation in the early phase of acute experimental colitis in the rat

BACKGROUND

Inflammatory bowel diseases are accompanied by severe motility disorders. The aim of our study was to investigate whether the blockade of peripheral N-methyl-D-aspartate (NMDA)-sensitive glutamate receptors (NMDA-Rs) alters motility changes in chemically induced acute colitis and how this modulation is accomplished.

METHODS

The inflammatory and motility changes in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis were studied in anaesthetized Wistar rats following treatment with the natural NMDA-R antagonist kynurenic acid (KynA) or SZR-72, a blood-brain barrier-permeable synthetic KynA analogue. The macrohaemodynamics, serosal microcirculation (visualized by intravital videomicroscopy), plasma levels of tumour necrosis factor alpha (TNF-alpha), inflammatory enzyme activities (xanthine oxidoreductase (XOR), myeloperoxidase (MPO) and nitric oxide synthase (NOS)), and colonic motility (with a strain-gauge technique) were evaluated 17 h after colitis induction and compared with the control conditions.

KEY RESULTS

The TNBS enema induced a systemic hyperdynamic circulatory reaction, increased the serosal capillary blood flow, significantly elevated the mucosal XOR, MPO and NOS activities and augmented the colonic motility relative to the controls. The NMDA-R antagonist treatment with KynA or SZR-72 significantly reduced the XOR, NOS and MPO activities, decreased the motility and increased the tone of the colon.

CONCLUSIONS & INFERENCES

These data demonstrate a potential modulatory mechanism of NMDA-R in altered colonic motility in TNBS colitis. Inhibition of the enteric NMDA-Rs may provide a therapeutic option via which to influence intestinal hypermotility, microcirculatory changes and inflammatory activation simultaneously.

Agonists of proteinase-activated receptor-2 modulate human neutrophil cytokine secretion, expression of cell adhesion molecules, and migration within 3-D collagen lattices

Proteinase-activated receptor-2 (PAR2) belongs to a novel subfamily of G-protein-coupled receptors with seven-transmembrane domains. PAR2 can be activated by serine proteases such as trypsin, mast cell tryptase, and allergic or bacterial proteases. This receptor is expressed by various cells and seems to be crucially involved during inflammation and the immune response. As previously reported, human neutrophils express functional PAR2. However, the precise physiological role of PAR2 on human neutrophils and its implication in human diseases remain unclear. We demonstrate that PAR2 agonist-stimulated human neutrophils show significantly enhanced migration in 3-D collagen lattices. PAR2 agonist stimulation also induced down-regulation of L-selectin display and up-regulation of membrane-activated complex-1 very late antigen-4 integrin expression on the neutrophil cell surface. Moreover, PAR2 stimulation results in an increased secretion of the cytokines interleukin (IL)-1beta, IL-8, and IL-6 by human neutrophils. These data indicate that PAR2 plays an important role in human neutrophil activation and may affect key neutrophil functions by regulating cell motility in the extracellular matrix, selectin shedding, and up-regulation of integrin expression and by stimulating the secretion of inflammatory mediators. Thus, PAR2 may represent a potential therapeutic target for the treatment of diseases involving activated neutrophils.

Induction of potent human immunodeficiency virus type 1-specific T-cell-restricted immunity by genetically modified dendritic cells

A novel technology combining replication- and integration-defective human immunodeficiency virus type 1 (HIV-1) vectors with genetically modified dendritic cells was developed in order to induce T-cell immunity. We introduced the vector into dendritic cells as a plasmid DNA using polyethylenimine as the gene delivery system, thereby circumventing the problem of obtaining viral vector expression in the absence of integration. Genetically modified dendritic cells (GMDC) presented viral epitopes efficiently, secreted interleukin 12, and primed both CD4(+) and CD8(+) HIV-specific T cells capable of producing gamma interferon and exerting potent HIV-1-specific cytotoxicity in vitro. In nonhuman primates, subcutaneously injected GMDC migrated into the draining lymph node at an unprecedentedly high rate and expressed the plasmid DNA. The animals presented a vigorous HIV-specific effector cytotoxic-T-lymphocyte (CTL) response as early as 3 weeks after a single immunization, which later developed into a memory CTL response. Interestingly, antibodies did not accompany these CTL responses, indicating that GMDC can induce a pure Th1 type of immune response. Successful induction of a broad and long-lasting HIV-specific cellular immunity is expected to control virus replication in infected individuals.

Dendritic cells and tumor immunity

Researchers and clinicians have tried for decades to use the mechanisms of immunity for the fight against cancer. Early attempts aimed at the instrumentation of soluble immune mediators such as antibodies or cytotoxic proteins for the therapy of malignancies. Major improvements in understanding the induction and regulation of cellular immunity have now made it possible to generate effector cells in cancer patients which are specific for the neoplastic disease. At the beginning of every cellular immune reaction against cancers tumor antigens have to be presented to T cells in order to activate them and drive them into clonal expansion. This is done by antigen presenting cells, the most powerful of which is the dendritic cell (DC). While DC were hard to isolate initially, they can be generated in large numbers in vitro today and manipulated in multiple ways before given back to a patient to induce tumor immunity. Thus, a great amount of hope lies in the use of DC as inducers of tumor immunity. However, the first clinical studies, which have now been completed with only limited success make clear, that still a lot of open questions remain to be answered. This review tries to give an overview of this rapidly developing field, mentioning the major conceptual approaches and techniques, but also discussing important caveats. The next years will show whether we can improve our understanding of DC biology and the mechanisms of immune induction strongly enough to effectively employ DC for immunotherapy of cancer.

Cloning of a new Kunitz-type protease inhibitor with a putative transmembrane domain overexpressed in pancreatic cancer

In a previous large scale screen for differentially expressed genes in pancreatic cancer, we identified a gene highly overexpressed in cancer encoding a novel putative transmembrane protein with two Kunitz-type serine protease inhibitor domains. The identified gene named kop (Kunitz domain containing protein overexpressed in pancreatic cancer) was assigned to chromosome 19 in the region 19q13.1. Kop was detected at high levels in pancreatic cancer cell lines and was overexpressed in pancreatic cancer tissues as compared to both, normal pancreas and chronic pancreatitis tissues. Being a member of the Kunitz-type serine protease inhibitor family, this new gene may participate in tumour cell invasion and metastasis and in the development of the marked desmoplastic reaction typical for human pancreatic cancer tissues. In this context, the fact that kop has a putative transmembrane domain may have functional implications of particular interest.

Assessment of the course of acute pancreatitis in the light of aetiology: a systematic review and meta-analysis

The main causes of acute pancreatitis (AP) are biliary disease, alcohol consumption, hypertriglyceridaemia (HTG) and endoscopic retrograde cholangiopancreatography (ERCP). The aim of this meta-analysis was to evaluate the effects of these aetiological factors on the severity and outcome of AP. Pubmed and Embase were searched between 01/01/2012 and 31/05/2020. Included articles involved adult alcoholic, biliary, HTG- or post-ERCP AP (PAP) patients. Primary outcome was severity, secondary outcomes were organ failures, intensive care unit admission, recurrence rate, pancreatic necrosis, mortality, length of hospital stay, pseudocyst, fluid collection and systematic inflammatory response syndrome. Data were analysed from 127 eligible studies. The risk for non-mild (moderately severe and severe) condition was the highest in HTG-induced AP (HTG-AP) followed by alcoholic AP (AAP), biliary AP (BAP) and PAP. Recurrence rate was significantly lower among BAP vs. HTG-AP or AAP patients (OR = 2.69 and 2.98, 95% CI 1.55–4.65 and 2.22–4.01, respectively). Mortality rate was significantly greater in HTG-AP vs. AAP or BAP (OR = 1.72 and 1.50, 95% CI 1.04–2.84 and 0.96–2.35, respectively), pancreatic necrosis occurred more frequently in AAP than BAP patients (OR = 1.58, 95% CI 1.08–2.30). Overall, there is a potential association between aetiology and the development and course of AP. HTG-AP is associated with the highest number of complications. Furthermore, AAP is likely to be more severe than BAP or PAP. Greater emphasis should be placed on determining aetiology on admission.

Bicarbonate and fluid secretion evoked by cholecystokinin, bombesin and acetylcholine in isolated guinea-pig pancreatic ducts

1. HCO3- secretion was investigated in interlobular duct segments isolated from guinea-pig pancreas using a semi-quantitative fluorometric method. Secretagogue-induced decreases in intracellular pH, following blockade of basolateral HCO3- uptake with a combination of amiloride and DIDS, were measured using the pH-sensitive fluoroprobe BCECF. Apparent secretory HCO3- fluxes were calculated from the initial rate of intracellular acidification. 2. In the presence of HCO3-, stimulation with secretin (10 nM) or forskolin (5 microM) more than doubled the rate of intracellular acidification. This effect was abolished in the absence of HCO3-. It was also abolished in the presence of HCO3- when DIDS and NPPB were applied to the luminal membrane by microperfusion. We therefore conclude that the increase in acidification rate is a useful index of secretagogue-induced HCO3- secretion across the luminal membrane. 3. Secretin, cholecystokinin (CCK) and bombesin each stimulated HCO3- secretion in a dose-dependent fashion. They evoked comparable maximal responses at about 10 nM and the EC50 values were 0.5 nM for secretin, 0.2 nM for CCK and 30 pM for bombesin. Acetylcholine (ACh) was also effective, with a maximum effect at 10 microM. 4. The stimulatory effect of CCK was blocked completely by the CCK1 receptor antagonist devazepide but not by the CCK2 receptor antagonist L365,260. The CCK analogue JMV-180 (Boc-Tyr(SO3H)-Nle-Gly-Trp-Nle-Asp-phenylethyl ester), which is an agonist of the high-affinity CCK1 receptor but an antagonist of the low-affinity receptor, also stimulated HCO3- secretion but with a smaller maximal effect than CCK. JMV-180 partially inhibited the response to a high concentration of CCK but not to a lower concentration, suggesting that both high- and low-affinity states of the CCK1 receptor evoke HCO3- secretion. 5. The stimulatory effect of bombesin was blocked completely by the gastrin-releasing peptide (GRP) receptor antagonist D-Phe6-bombesin(6-13)-methyl ester (BME) but not by the neuromedin B (NMB) receptor antagonist D-Nal-cyclo[Cys-Tyr-D-Trp-Orn-Val-Cys]-Nal-NH2 (BIM-23127). 6. Secretagogue-evoked fluid secretion was also examined using video microscopy to measure the rate of swelling of ducts whose ends had sealed during overnight culture. Secretin, CCK, bombesin and ACh all evoked fluid secretion with maximal rates of approximately 0.6 nl x min(-1) x mm(-2), and with concentration dependences similar to those obtained for HCO3- secretion. 7. We conclude that CCK, bombesin and ACh stimulate the secretion of a HCO3--rich fluid by direct actions on the interlobular ducts of the guinea-pig pancreas and that these responses are mediated by CCK1 receptors, GRP receptors and muscarinic cholinoceptors, respectively.

Comparison of dialysis and clinical characteristics of patients with frequent and occasional hemodialysis-associated hypotension

BACKGROUND

Symptomatic dialysis hypotension (DH) continues to be a common problem. By comparing patients prone and resistant to DH, several dialysis session and patient related characteristics have been identified that confer susceptibility to DH. Less is known, however, about the comparison of patients with frequent and only occasional DH. The aim of the study was to compare clinical and dialysis-session- (complicated by hypotension) related data between those with frequent (fDH) and those with occasional dialysis hypotension (oDH).

METHODS

Nine hundred and fifty-eight patients at 11 dialysis units were followed for 10 months and characteristics of patients with fDH (> or = 10 hypotensive events necessitating medical intervention) (n = 96) were compared to that of patients with oDH (1 or 2 events/10 months) (n = 130). Significant and independent predictors of fDH were obtained by multivariate logistic regression.

RESULTS

Significant differences between fDH vs. oDH patients were older age (64.4 vs. 56.9 years, p < 0.001), more females (66 vs. 46%, p < 0.005) in fDH. More fDH patients had diabetes (27 vs. 15%, p < 0.05) and less had glomerulonephritis (15 vs. 35%, p < 0.001) as the cause for ESRD. Coronary artery disease (68 vs. 50%, p < 0.01) and long-acting nitrate treatment (51 vs. 30%, p < 0.001) was more frequent while treatment with ACEI (33 vs. 48%, p < 0.05) or Ca-channel blockers (40 vs. 53%, p < 0.05) were less frequent in patients with fDH. Patients with fDH had higher serum phosphorus levels (1.99 vs. 1.79 mmol, p < 0.005). Dialysis session related data were similar but the hypotensive episode occurred earlier during dialysis in fDH (136 vs. 156 min, p < 0.01). In multivariate analysis, significant independent predictors of fDH were older age (OR = 1.04 [1.02-1.07]), lack of glomerulonephritis as renal diagnosis (2.63 [1.18-5.87]), high phosphorus levels (5.0 [2.45-10.0]), lack of use of Ca-channel blockers (2.09 [1.12-3.91]), and the use of nitrates (2.38 [1.24-4.55]).

CONCLUSION

Features of the dialysis sessions complicated by DH seem to be similar between patients with fDH and oDH, while patient characteristics such as older age, renal diagnosis other than glomerulonephritis, higher serum phosphorus levels, use of nitrates, and lack of use of calcium channel blockers are significantly and independently associated with fDH.

Effects of potent bombesin antagonist on exocrine pancreatic secretion in rats

Recent synthesis of specific, potent bombesin receptor antagonists allows examination of the role of bombesin-like peptides in physiological processes in vivo. We characterized effects of [D-Phe6]bombesin(6-13)-methyl-ester (BME) on pancreatic enzyme secretion stimulated by the C-terminal decapeptide of gastrin releasing peptide (GRP-10), food intake, and diversion of bile-pancreatic juice in rats. In isolated pancreatic acini, BME had no agonistic effects on amylase secretion but competitively inhibited responses to GRP-10, yielding a pA2 value of 8.89 +/- 0.19. In conscious rats with gastric, jugular vein, bile-pancreatic, and duodenal cannulas, basal enzyme secretion (bile-pancreatic juice recirculated) was not affected by the antagonist. Maximal amylase response to GRP-10 (0.5 nmol/kg/h) was inhibited dose dependently by BME, reaching 97% inhibition at a dose of 400 nmol/kg/h. The dose response curve of amylase secretion stimulated by GRP-10 was shifted to the right by 40 nmol/kg/h BME, but maximal amylase response was unaltered, suggesting competitive inhibition in vivo. Liquid food intake and bile-pancreatic juice diversion caused substantial increases in amylase secretion; neither response was altered during administration of 400 pmol/kg/h BME. These results demonstrate that BME is a potent, competitive antagonist of pancreatic responses to bombesin-like peptides in vitro and in vivo. Lack of effect of BME on basal pancreatic secretion or responses to liquid food intake or diversion of bile-pancreatic juice in rats suggests that endogenous bombesin-like peptides do not act either directly or indirectly to mediate these responses.

Evaluation of palatal saliva flow rate and oral manifestations in patients with Sjögren's syndrome

OBJECTIVE

The purpose of this study was to describe the oral properties of Sjögren's syndrome (SS), including the determination of palatal saliva (PS) flow rate.

SUBJECTS AND METHODS

Forty-nine SS patients and 43 healthy controls participated. Subjective symptoms were recorded and clinical assessments of the oral mucosal, dental and periodontal status were made. Unstimulated whole saliva (WS) and PS flow rates, the number of decayed, missing and filled teeth (DMF-T number), the gingival bleeding index (GBI) and the periodontal probing depth (PPD) were determined.

RESULTS

Despite the decrease in the flow rate of WS in SS patients, PS was not different from those of the controls (1.57 +/- 1.02 and 1.35 +/- 2.5 microl cm(-2) min(-1), respectively). GBI (20.0% vs. 10.5%, respectively), DMF-T (27.1 +/- 6.12 vs. 23.0 +/- 6.99, respectively) and PPD (2.28 +/- 1.09 mm vs. 1.82 +/- 0.73 mm, respectively) were higher in SS compared with the controls (P < 0.05). DMF-T and PPD showed a positive correlation with anti-SSA and/or anti-SSB antibody positivity in the serum (P < 0.05).

CONCLUSIONS

Data of the present study suggest that the subjective feeling of xerostomia in SS patients is the result of a decrease in the volume of the whole saliva, and not of the viscous PS. Correlation of DMF-T and PPD with autoantibody positivity reveals that the oral health status of SS patients may be associated with the general autoimmune process.

Effect of CCK and its antagonists on gastric emptying

Cholecystokinin (CCK) belongs to the group of substances known as brain-gut peptides: it functions both as a neuropeptide and a gut hormone. The peptide and its synthetic derivatives (like for instance CCK-8 and the amphibian counterpart caerulein) significantly delay emptying of gastric contents in both animals and humans. The fact that CCK, in doses mimicking postprandial plasma levels, strongly affects emptying rate suggests the peptide to be a physiologic regulator of gastric emptying. Unfortunately, clear definition of the role of CCK in the physiology of gastric motor activity has long been hampered by the lack of specific and potent non-peptide antagonists of CCK-receptors. The availability of such compounds has stimulated a broad array of investigations into the physiological actions of this hormone and examination of its putative role in certain diseases. This paper summarizes the available data concerning the effect of CCK and its antagonists on gastric emptying. The use of selective CCK-antagonists has allowed to establish that the gastric motor effect of the peptide is direct and mediated through the stimulation of CCK-A receptors. As a consequence, CCK-A antagonism results in acceleration of emptying rate under certain experimental and clinical conditions. This peculiar pharmacologic effect of CCK-A antagonists, which could be useful in the treatment of functional dyspepsia (idiopathic or diabetic), gastroparesis and gastro-esophageal reflux disease (where patients often display a delayed emptying rate of solid food) needs to be further investigated, in order to fully explore their potential as gastrokinetic drugs.