Different patterns of intrinsic functional connectivity at the default mode and attentional networks predict crystalized and fluid abilities in childhood

Crystallized abilities are skills used to solve problems based on experience, while fluid abilities are linked to reasoning without evoke prior knowledge. To what extent crystallized and fluid abilities involve dissociated or overlapping neural systems is debatable. Due to often deployed small sample sizes or different study settings in prior work, the neural basis of crystallized and fluid abilities in childhood remains largely unknown. Here we analyzed within and between network connectivity patterns from resting-state functional MRI of 2707 children between 9 and 10 years from the ABCD study. We hypothesized that differences in functional connectivity at the default mode network (DMN), ventral, and dorsal attentional networks (VAN, DAN) explain differences in fluid and crystallized abilities. We found that stronger between-network connectivity of the DMN and VAN, DMN and DAN, and VAN and DAN predicted crystallized abilities. Within-network connectivity of the DAN predicted both crystallized and fluid abilities. Our findings reveal that crystallized abilities rely on the functional coupling between attentional networks and the DMN, whereas fluid abilities are associated with a focal connectivity configuration at the DAN. Our study provides new evidence into the neural basis of child intelligence and calls for future comparative research in adulthood during neuropsychiatric diseases.

Dynamic Functional Connectivity as a complex random walk: Definitions and the dFCwalk toolbox

•We have developed a framework to describe the dynamics of Functional Connectivity (dFC) estimated from brain activity time-series as a complex random walk in the space of possible functional networks. This conceptual and methodological framework considers dFC as a smooth reconfiguration process, combining "liquid" and "coordinated" aspects. Unlike other previous approaches, our method does not require the explicit extraction of discrete connectivity states.•In our previous work, we introduced several metrics for the quantitative characterization of the dFC random walk. First, dFC speed analyses extract the distribution of the time-resolved rate of reconfiguration of FC along time. These distributions have a clear peak (typical dFC speed, that can already serve as a biomarker) and fat tails (denoting deviations from Gaussianity that can be detected by suitable scaling analyses of FC network streams). Second, meta-connectivity (MC) analyses identify groups of functional links whose fluctuations co-vary in time and that define veritable dFC modules organized along specific dFC meta-hub controllers (differing from conventional FC modules and hubs). The decomposition of whole-brain dFC by MC allows performing dFC speed analyses separately for each of the detected dFC modules.•We present here blocks and pipelines for dFC random walk analyses that are made easily available through a dedicated MATLABⓇ toolbox (dFCwalk), openly downloadable. Although we applied such analyses mostly to fMRI resting state data, in principle our methods can be extended to any type of neural activity (from Local Field Potentials to EEG, MEG, fNIRS, etc.) or even non-neural time-series.

Modular slowing of resting-state dynamic functional connectivity as a marker of cognitive dysfunction induced by sleep deprivation

Dynamic Functional Connectivity (dFC) in the resting state (rs) is considered as a correlate of cognitive processing. Describing dFC as a flow across morphing connectivity configurations, our notion of dFC speed quantifies the rate at which FC networks evolve in time. Here we probe the hypothesis that variations of rs dFC speed and cognitive performance are selectively interrelated within specific functional subnetworks. In particular, we focus on Sleep Deprivation (SD) as a reversible model of cognitive dysfunction. We found that whole-brain level (global) dFC speed significantly slows down after 24h of SD. However, the reduction in global dFC speed does not correlate with variations of cognitive performance in individual tasks, which are subtle and highly heterogeneous. On the contrary, we found strong correlations between performance variations in individual tasks -including Rapid Visual Processing (RVP, assessing sustained visual attention)- and dFC speed quantified at the level of functional sub-networks of interest. Providing a compromise between classic static FC (no time) and global dFC (no space), modular dFC speed analyses allow quantifying a different speed of dFC reconfiguration independently for sub-networks overseeing different tasks. Importantly, we found that RVP performance robustly correlates with the modular dFC speed of a characteristic frontoparietal module.

Dynamic Functional Connectivity between order and randomness and its evolution across the human adult lifespan

Functional Connectivity (FC) during resting-state or task conditions is not static but inherently dynamic. Yet, there is no consensus on whether fluctuations in FC may resemble isolated transitions between discrete FC states rather than continuous changes. This quarrel hampers advancing the study of dynamic FC. This is unfortunate as the structure of fluctuations in FC can certainly provide more information about developmental changes, aging, and progression of pathologies. We merge the two perspectives and consider dynamic FC as an ongoing network reconfiguration, including a stochastic exploration of the space of possible steady FC states. The statistical properties of this random walk deviate both from a purely "order-driven" dynamics, in which the mean FC is preserved, and from a purely "randomness-driven" scenario, in which fluctuations of FC remain uncorrelated over time. Instead, dynamic FC has a complex structure endowed with long-range sequential correlations that give rise to transient slowing and acceleration epochs in the continuous flow of reconfiguration. Our analysis for fMRI data in healthy elderly revealed that dynamic FC tends to slow down and becomes less complex as well as more random with increasing age. These effects appear to be strongly associated with age-related changes in behavioural and cognitive performance.

Relationship between hospital size and teaching status on outcomes for reverse shoulder arthroplasty

BACKGROUND

The use of reverse shoulder arthroplasty (RSA) continues to grow with expanding indications and increased surgeon awareness. Previous data for other lower extremity joint replacements indicate that high-volume centers have better outcomes, with lower complication rates, decreased length of stay, and complications for both hemiarthroplasty and total shoulder arthroplasty. The purpose of this study is to evaluate the effects of hospital size and setting on adverse events for RSA.

MATERIALS AND METHODS

The National Inpatient Sample database was queried for RSA performed using ICD-9 codes. Primary outcomes included length of stay (LOS), total hospital charges, discharge disposition, and postoperative complications. Odds ratios were used to assess the risk of inpatient postoperative complications.

RESULTS

A weighted national estimate of 24,056 discharges for patients undergoing RSA was included in the study. Patients at larger hospitals experienced higher total charges, increased average LOS, and slightly higher complication rates compared to those of small and medium hospitals. Patients in larger hospitals had significantly increased rates of genitourinary and central nervous system complications, while patients in small/medium hospitals experienced higher rates of hematoma/seroma.

CONCLUSION

Results from this study indicate that large and non-teaching hospitals overall tend to burden the patients with higher hospital charges, longer hospital stay, and more frequent non-routine discharges. Also, larger hospitals are associated with higher risk of genitourinary and central nervous system complications rates, whereas non-teaching hospitals are associated with lower risk of infection and higher risk of anemia after RSA. With the growth in RSA in the USA, continued attention needs to be placed on improving outcomes and resource utilization for RSA patients even in larger hospitals.

CAEV: Vorläufige Ergebnisse eines alternativen Protokolls zur Kontrolle der CAE in einem Ziegenbetrieb der Rasse »Passeirer Gebirgsziege«

Gegenstand und Ziel: In der vorliegenden Arbeit wird über ein alternatives Protokoll zur Kontrolle der CAE berichtet, das die Gegebenheiten des Betriebes (hohe Seroprävalenz, seltene Ziegenrasse mit hohem Zuchtwert, gemeinsame Alpung) berücksichtigte. Das Ziel war, die Krankheit bzw. die klinischen Symptome zurückzudrängen und das hohe genetische Potenzial dieser Ziegenherde möglichst zu erhalten. Material und Methode: Die Neugeborenen wurden vom Muttertier getrennt und mit Rinderkolostrum/-milch aufgezogen. Im Alter von fünf bis sechs Monaten hatten sie auf der Weide Kontakt zu den Adulten. Seropositive Tiere wurden nicht a priori geschlachtet. Ziegen mit geringem Zuchtwert wurden verkauft oder geschlachtet, jene mit hohem Zuchtwert wurden so lange wie möglich in der Herde belassen. Ergebnisse und Schlussfolgerung: Obwohl eine Infektion erwartungsgemäß nicht verhindert werden konnte, blieben die Krankheitsfälle bis dato aus. Im vorliegenden Betrieb dürfte eine aerogene und sexuelle Übertragung eine nicht unerhebliche Rolle gespielt haben. Das hohe genetische Potenzial dieser Ziegenherde ließ sich weitgehend erhalten. Klinische Relevanz: Bei der Erstellung eines »Sanierungsmodells« müssen Ziel, Wille und Ausdauer des Besitzers und das Umfeld mitberücksichtigt werden. Die beschriebene Methode scheint zum derzeitigen Zeitpunkt als geeignet, wenn der Betrieb überdurchschnittlich wertvolle Ziegen hält, die Seroprävalenz bereits hoch ist und die benachbarten Ziegen einen unbekannten serologischen Status aufweisen. Eine erneute Beurteilung zu einem späteren Zeitpunkt ist gewiss erforderlich. Die Nachteile umfassen die Viruspersistenz und den großen Arbeitsaufwand durch die jährliche mutterlose Aufzucht der Neugeborenen.

Pedunculated liposarcoma of the esophagus

Polypoid tumours of the esophagus present diagnostic and therapeutic problems. Liposarcomas are infrequent among them. We report a recent case. A 73-year-old male patient was seen in May 1995 in the Ear, Nose and Throat (ENT) Department, Clinica Modelo de Morón, with intermittent dysphagia and dyspnoea due to recurrent vomiting. A laryngeal lineal tomography showed a subglottic obstruction due to extrinsic compression. The patient was referred to the Gastroenterology Department, where an upper gastrointestinal (upper GI) series demonstrated mega-esophagus with abundant retained food. Endoscopy showed a large intraluminal mass covered by normal mucosa which arose on the posterior wall. Videofluoroscopy and chest CT diagnosed a probable polypoid lipoma due to its densitometric characteristics. The tumour was resected by left cervicotomy and left esophagotomy. The patient's progress to date is favourable. Pathology studies showed a well-differentiated liposarcoma. According to the literature, the first case was reported in 1983, and ours is only the seventh case in the world to be documented.

Cerebrospinal fluid examination may be useful in diagnosing neurosyphilis in asymptomatic HIV+ patients with syphilis

Lumbar puncture in neurologically asymptomatic HIV+ patients is still under debate. There are different criteria for detecting neurosyphilis through cerebrospinal fluid (CSF), especially in cases that are negative through the Venereal Disease Research Laboratory (VDRL), regarding cellularity and protein content. However, a diagnosis of neurosyphilis can still exist despite negative VDRL. Treponema pallidum hemagglutination assay (TPHA) titers and application of the TPHA index in albumin and IgG improve the sensitivity, with a high degree of specificity. Thirty-two patients were selected for this study. VDRL was positive in five of them. The number of diagnoses reached 14 when the other techniques were added. It was not determined whether cellularity and increased protein levels were auxiliary tools in the diagnosis. According to our investigation, CSF analysis using the abovementioned techniques may be useful in diagnosing neurosyphilis in these patients.

The effect of deltoid lengthening on functional outcome for reverse shoulder arthroplasty

PURPOSE

Reverse shoulder arthroplasty (RSA) is based on the biomechanical advantages of lengthening the deltoid while medializing its center of rotation (COR). Little evidence exists describing the clinical benefits of these biomechanical advantages. The purpose of this study is to assess the relationship between deltoid lengthening and medialization of the COR with functional outcomes for RSA patients.

METHODS

We retrospectively reviewed patients treated with primary RSA. Radiographic measurements of deltoid length and COR, assessment of forward elevation (FE) and external rotation (ER), and functional outcome scores were obtained pre- and postoperatively. Linear regression analyses were performed to assess the relationship between these radiographic measurements and changes in shoulder functionality.

RESULTS

On average, patients improved significantly in function and functional outcome scores. Postoperative COR correlated weakly with postoperative FE. There were weakly negative correlations between increase in acromion to greater tuberosity distance and postoperative FE, and between deltoid lengthening and FE improvement.

CONCLUSIONS

Our results suggest that deltoid lengthening does not correlate with improvements in active FE or ER. These findings could indicate that change in deltoid length is less important than previously thought. Furthermore, the negative correlations seen could indicate that there is over-tensioning of the deltoid in specific cases. Further studies are needed to better assess the role of deltoid length and other factors that may impact RSA outcomes.

Ease-of-use protocol for the rapid detection of third-generation cephalosporin resistance in Enterobacteriaceae isolated from blood cultures using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry

An ease-of-use protocol for the identification of resistance against third-generation cephalosporins in Enterobacteriaceae isolated from blood culture bottles was evaluated using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. A cefotaxime hydrolysis assay from chocolate agar subcultures using antibiotic discs and without inoculum standardization was developed for routine work flow, with minimal hands-on time. This assay showed good performance in distinguishing between cefotaxime-susceptible and cefotaxime-resistant strains, with excellent results for Escherichia coli (sensitivity 94.7%, specificity 100%). However, cefotaxime resistance was not detected reliably in Enterobacteriaceae expressing AmpC genes or carbapenemase-producing Klebsiella pneumoniae.

Immunohistochemical analysis of the hypothalamic-pituitary-adrenal axis in dogs: Sex-linked and seasonal variation

This study evaluated sexual dimorphism and seasonal variations in corticotrophs and adrenal zona fasciculata in dogs, as well as the expression of oestrogen receptor alpha (ERα). An immunohistochemical analysis was conducted in pituitaries for ACTH and in adrenal glands for ERα and for the melanocortin-2-receptor (MC2R) in winter and summer. Double immunofluorescence was performed to identify ERα in corticotrophs. Females had a greater proportion of corticotrophs per field (p<0.01), with a greater cellular area and optical density (p<0.001) than males. Optical density of corticotrophs was greater in winter for both sexes (p<0.001). In zona fasciculata, ERα and MC2R expression was greater in females (p<0.001) and was greater in winter (p<0.001). ERα was identified in corticotrophs. This study is the first to demonstrate ERα expression in corticotrophs and the adrenal cortex in dogs, providing evidence for sexual dimorphism and seasonal variations.

Fertilization defects in sperm from Cysteine-rich secretory protein 2 (Crisp2) knockout mice: implications for fertility disorders

STUDY HYPOTHESIS

We hypothesize that fertility disorders in patients with aberrant expression of Cysteine-RIch Secretory Protein 2 (CRISP2) could be linked to the proposed functional role of this protein in fertilization.

STUDY FINDING

Our in vivo and in vitro observations reveal that Crisp2-knockout mice exhibit significant defects in fertility-associated parameters under demanding conditions, as well as deficiencies in sperm fertilizing ability, hyperactivation development and intracellular Ca(2+) regulation.

WHAT IS KNOWN ALREADY

Testicular CRISP2 is present in mature sperm and has been proposed to participate in gamete fusion in both humans and rodents. Interestingly, evidence in humans shows that aberrant expression of CRISP2 is associated with male infertility.

STUDY DESIGN, SAMPLES/MATERIALS, METHODS

A mouse line carrying a deletion in the sixth exon of the Crisp2 gene was generated. The analyses of the reproductive phenotype of Crisp2(-/-) adult males included the evaluation of their fertility before and after being subjected to unilateral vasectomy, in vivo fertilization rates obtained after mating with either estrus or superovulated females, in vitro sperm fertilizing ability and different sperm functional parameters associated with capacitation such as tyrosine phosphorylation (by western blot), acrosome reaction (by Coomassie Blue staining), hyperactivation (by computer-assisted sperm analysis) and intracellular Ca(2+) levels (by flow cytometry).

MAIN RESULTS AND THE ROLE OF CHANCE

Crisp2(-/-) males presented normal fertility and in vivo fertilization rates when mated with estrus females. However, the mutant mice showed clear defects in those reproductive parameters compared with controls under more demanding conditions, i.e. when subjected to unilateral vasectomy to reduce the number of ejaculated sperm (n = 5; P< 0.05), or when mated with hormone-treated females containing a high number of eggs in the ampulla (n ≥ 5; P< 0.01). In vitro fertilization studies revealed that Crisp2(-/-) sperm exhibited deficiencies to penetrate the egg vestments (i.e. cumulus oophorus and zona pellucida) and to fuse with the egg (n ≥ 6; P< 0.01). Consistent with this, Crisp2-null sperm showed lower levels of hyperactivation (n = 7; P< 0.05), a vigorous motility required for penetration of the egg coats, as well as a dysregulation in intracellular Ca(2+) levels associated with capacitation (n = 5; P< 0.001).

LIMITATIONS, REASONS FOR CAUTION

The analysis of the possible mechanisms involved in fertility disorders in men with abnormal expression of CRISP2 was carried out in Crisp2 knockout mice due to the ethical and technical problems inherent to the use of human gametes for fertilization studies.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings in mice showing that Crisp2(-/-) males exhibit fertility and fertilization defects under demanding conditions support fertilization defects in sperm as a mechanism underlying infertility in men with aberrant expression of CRISP2. Moreover, our observations in mice resemble the situation in humans where fertility disorders can or cannot be detected depending on the accumulation of own individual defects or the fertility status of the partner. Finally, the fact that reproductive defects in mice are masked by conventional mating highlights the need of using different experimental approaches to analyze male fertility.

STUDY FUNDING AND COMPETING INTERESTS

This study was supported by the World Health Organization (H9/TSA/037), the National Research Council of Argentina (PIP 2009-290), the National Agency for Scientific and Technological Promotion of Argentina (PICT 2011, 2023) and the Rene Baron Foundation to P.S.C. and by the MEXT of Japan to M.I. The authors declare that there are no conflicts of interest.

Topical use of phytotherapic cream (Capilen® cream) to prevent radiodermatitis in breast cancer: a prospective historically controlled clinical study

AIM

The purpose of this study was to evaluate the ability of a topical phytotherapic product (Capilen® cream) to limit acute radiodermitis and delay the use of corticosteroids in patients with breast cancer (BC).

METHODS

From January 2012 to August 2012, 30 consecutive patients, undergoing radiotherapy with adjuvant intent, were invited to use Capilen® cream two times daily two weeks before and during radiotherapy. An historical group was used as an external control. Acute skin toxicity was scored weekly according to RTOG/EORTC criteria. Time of occurrence of acute skin toxicity was taken as endpoint.

RESULTS

Compliance was good. Overall, no significative statistical difference was observed in rate of acute radiation dermatitis, 46.7% in experimental arm versus 63.3% in the historical control group, although only 3.3% of Capilen® cream treated patients had a G3 acute radiation dermatitis versus 10% of the control group. A delay in the onset of radition dermatitis in patients treated with Capilen® cream (P=0.04) was showed.

CONCLUSION

Our findings suggested that Capilen® cream plays a role in reducing acute radiation dermatitis in breast cancer patients treated with adjuvant radiotherapy. Further evidence is needed to confirm these results.

309 MORPHOMETRICAL ANALYSIS OF THE LAMA GLAMA SPERM HEAD

During the last decades, the interest in breeding South American Camelids has increased, not only as companion animals but also for their high- quality fiber. Although several studies have been carried out on artificial insemination in Lama glama, this technique has not been widely applied in reproductive programs, principally due to the difficulty in collecting raw semen from males and the lack of knowledge about freezing/thawing techniques and semen characteristics. The aim of the present study was to objectively characterize llama sperm morphometry by a computer-assisted system, thereby increasing the knowledge on male llama physiology, leading to further developement of reproductive biotechnologies such as artificial insemination. Five semen samples were obtained by electroejaculation from each of 8 males, 6- to 10-year-old llamas of proven fertility. Smears were prepared from each sample and stained with Tinción 15® (Biopur S.R.L., Rosario, Argentina) and observed at x 1000 magnification. Images of sperm heads were captured by a Leica DC180 camera (Leica Microsystems Co., Wetzlar, Germany), obtaining 200 images from each sample. Binary images were obtained and area, length, width, equivalent circle diameter, curve length, curve width, perimeter, convex perimeter, roundness, and elongation were measured using QWin Plus (Leica Microsystems Co.). A total of 8005 sperm heads were measured. Descriptive statistics of the complete population was performed, with the following results obtained (mean ± SD): area (μm2) 20.09 ± 0.6, length (μm) 6.6 ± 0.3, width (μm) 4.14 ± 0.1, equivalent diameter ((μm) 5.06 ± 0.1, curve length (μm) 5.8 ± 0.3, curve width (μm) 3.48 ± 0.3, perimeter (μm) 18.54 ± 0.1, convex perimeter (μm) 17.34 ± 0.3, roundness 1.28 ± 0.04, and elongation 1.6 ± 0.01. Coefficients of variation were between 0.47 and 8.72%. A design considering the male as a fixed factor and the ejaculate as a nested factor was used for the purpose of identifying differences in morphometry between ejaculates of the same male and/or between males. Normality was tested using the Kolmogorov test. Significant differences between ejaculates of some males were found for curve length, curve width, perimeter, roundness, and elongation (P < 0.05). There were no intra-male differences for sperm head area, length, width, equivalent circle diameter, and convex perimeter. Of the parameters, there were significant differences between males for sperm area, length, equivalent circle diameter, and convex perimeter (P < 0.05). The differences found in sperm morphometry confirm the great polymorphism observed when subjectively evaluating llama semen morphology and make the establishment of a single pattern of normal llama sperm morphometry impossible.

Histone deacetylase (HDAC) encoding gene expression in pancreatic cancer cell lines and cell sensitivity to HDAC inhibitors

PURPOSE

Multiple biochemical and molecular alterations occur in pancreatic cancer cells. In the present study, attempts were made for the first time, to explore the level of expression of members of histone deacetylase encoding genes (HDACs) in four pancreatic tumor cell lines: Panc-1, BxPC-3, SOJ-6 and MiaPaCa-2; and two non-related tumor cells: Jurkat and HeLa. Furthermore, we examined the possible relationship between the levels of HDACs expression and the sensitivity/resistance to HDAC inhibitors (TSA, Nicotinamide and Sirtinol).

RESULTS

We have found that although a slight variation in the profiles of gene expression among cell lines could be evidenced, HDACs protein synthesis seem to be similar. Furthermore, the cells were equally sensitive to inhibition by Sirtinol whereas some variation in the IC(50) could be seen in the case of TSA. We also demonstrate that the drugs had the capacity to induce the death of cells by apoptosis.

METHODS

We have used four human pancreatic tumor cell lines and two-non related tumor cells, to evaluate the expression of HDAC encoding genes by RT-PCR and Western blot analysis. We also measured the effect of certain HDAC inhibitors (HDIs) on cell growth, cell cycle alteration, membrane phosphatidyl-serine exposure, DNA fragmentation and mitochondrial membrane potential loss.

CONCLUSIONS

Taken together, our data support the notion that the level of cell sensitivity to the HDIs might be related to the level of expression of genes such as those encoding proteins playing a role in cell cycle checkpoints control but not HDAC per se.

Isolation of human anti-idiotypic antibodies by phage display for clinical immune response assays

The clinical development of therapeutic proteins requires assays that measure the pharmacokinetic (PK) profile of, and the potential immune response (IR) to, the protein agent. Each assay requires reagents that are highly specific for the therapeutic protein. For therapeutic monoclonal antibodies, anti-CDR-specific, or anti-idiotypic (anti-id), antibodies are an ideal class of reagents suitable for these assays because of their high specificity and affinity to the drug antibody. We generated anti-ids to two human antibodies by antibody phage display using the MorphoSys HuCAL GOLD Fab library. To selectively target the CDR regions, serum and a framework-matched mAb were included as competitors during the phage selection process. Panels of CDR-specific Fabs, with low to sub-nM affinities, were isolated against both targets. The CDR specificity of these Fabs was shown by their lack of binding to a framework-matched control mAb and by competition of this binding with the soluble antigens of the respective therapeutic mAb targets. The candidate anti-id Fabs were able to detect both immobilized and soluble target Ab without being affected by serum, a requirement for both PK assay and the IR bridging assay format. Combinations of the Fabs for PK detection assays were identified by pairwise binding studies, although the pair for one target mAb lacks the desired sensitivity for PK assays. To evaluate their potential as anti-drug antibodies (ADAs), the best Fabs for one of the targets were converted and produced as the required bivalent human mAbs. In comparison to rodent mAbs and primate polyclonal serum, the phage display derived human mAbs were equally effective as reference standards. Our results demonstrate that competition-based phage selection can be an effective method for the isolation of anti-idiotypic antibodies for PK and IR assay development, and in this latter case, overcome limitations of current methods using rodent derived anti-ids.

Contactless measurement strategies and apparatus for mandibular movements monitoring in gnatology

This paper deals with the development of an innovative approach that allows performing non invasive measurements of jaw movements with application to the field of gnatography. An experimental apparatus has been also realized that includes both hardware and software sections. The main characterizing feature of the measurement system proposed here consist in the complete absence of any invasive device with respect to the patient, in fact a stereoscopic artificial vision approach has been exploited to our aims. A large set of experimental verifications of the proposed strategy has been performed and the results obtained confirm the suitability of the approach.

Detection of bile salt-dependent lipase, a 110 kDa pancreatic protein, in urines of healthy subjects

Bile salt-dependent lipase (BSDL), a 110 kDa glycoprotein secreted by the pancreatic acinar cells, participates in the duodenal hydrolysis of dietary lipid esters. Recent in vitro and in vivo studies demonstrated that the BSDL reaches the blood via a transcytosis motion through enterocytes, suggesting that this enzyme may play a role in vascular biology. Once in the blood, BSDL should be eliminated. We address the hypothesis that BSDL may be filtered by the glomerulus and eliminated in urines. Immunological methods and proteomic were used to detect and to characterize BSDL in urine. The immunoreactive form of BSDL was detected in urines of 36 male subjects devoid of renal failure. Proteomic demonstrated that the immunoreactive protein is BSDL. Experiments using a monoclonal antibody to the oncofetal glycoform of pancreatic BSDL suggested that the protein is not expressed by renal cells but originates from the pancreas via circulation. We demonstrate that under normal physiological conditions, BSDL, a high-molecular weight blood glycoprotein, can be filtered by the renal glomerulus to be eliminated in urines.

Identification of γδT lymphocytes in human periapical lesions

Endodontic (root canal) therapy is required when the pulp of a tooth becomes necrotic due to a bacterial infection or trauma. A proportion of patients who receive endodontic therapy subsequently have periapical (around the tooth root) lesions detected by radiolucency. Currently, there are no means to identify susceptible patients. Although tissue from periapical lesions has been described as inflammatory, inflammatory cell types and their functions have been poorly characterized. For example, T lymphocytes were identified using pan specific anti-CD3 mAb, which recognizes both alphabeta and gammadeltaT cells. Using the current model of gammadeltaT cells as immunoregulatory cells; gammadeltaT cells can mediate protective or destructive milieus. We postulated that patients who have a periapical lesion, as identified by radiographic bone loss, mount a gammadeltaT cell response. We collected specimens removed by surgery from both periapical lesions and other oral tissues, generated total RNA and performed reverse-transcriptase polymerase chain reaction to identify rearranged delta genes. Results were confirmed with semi-nested polymerase chain reaction. In addition, we demonstrate that these lesions contain a population of CD3+ cells that are alphabetaT cell receptor negative, implying that these cells are gammadeltaT cells. Here we show that 36/37 of periapical lesions and only 2/11 of other lesions contain gammadeltaT cells (P<0.0001). Vdelta2+ T cells were the most common subtype identified (30/36) in these samples. This is the first report in the literature of the presence of gammadeltaT cells in human periapical lesions.

Observation of a re-entrant kinetic glass transition in a micellar system with temperature-dependent attractive interaction

We detect in a tri-block co-polymer micellar system an ergodic-to-nonergodic-to-ergodic transition, as a function of temperature, in a range of concentrations, by photon correlation measurements. The shear viscosity is also shown to jump two order of magnitude at these transition temperatures. Surprisingly, the structure factor as measured by small angle neutron scattering shows a marked narrowing at the structural arrest state. Rationalization of these results with the existence of an attractive branch in the phase diagram of an attractive colloid system predicted by mode coupling theory is made.

Transcytosis of pancreatic bile salt-dependent lipase through human Int407 intestinal cells

In previous studies, we have shown that the bile-salt-dependent-lipase (BSDL), secreted by pancreatic acinar cells and secreted into the duodenal lumen, can be transcytosed through intestinal cells up to the lamina propria. In this study, we used an in vitro system to provide insights into the apical to basolateral transport of BSDL, across the intestinal barrier. The Int407 human epithelial cell line, grown under conditions that optimize polarity, was used as a tight epithelium model. We attempted to delineate uptake mechanisms and the transcytotic pathway followed by this pancreatic enzyme within the intestinal Int407 cells, which do not produce BSDL. When added to the apical reservoir of Transwell-grown Int407 cells, BSDL was shown to first interact with the apical membrane. Further, BSDL forms clusters that are internalized via clathrin-coated pits. Following endocytosis, BSDL is directed to a nocodazole- and colchicin-sensitive multivesicular compartment. Interestingly, this protein transits through the Golgi apparatus, where it was found to colocalize with the KDEL retrieval-receptor. Finally, enzymatically active intact BSDL was released at the basolateral membrane level. This is the first demonstration for an apical-to-basolateral transcytotic pathway of a secreted pancreatic digestive enzyme through polarized intestinal cells.

Effect of ischemia-reperfusion on bile canalicular F-actin microfilaments in hepatocytes of human liver allograft: image analysis by confocal laser scanning microscopy

We studied and quantified the effect of ischemia-reperfusion on hepatic F-actin on bile canalicular and basolateral membranes in human liver allografts by means of confocal laser scanning microscopy imaging. The phalloidin-FITC staining of F-actin was normal in liver hepatocytes before reperfusion but decreased significantly after reperfusion (by 25% of controls). These results indicate that hepatic F-actin alteration is produced during the reperfusion phase. This modification, probably induced by reactive oxygen species, could impair bile canalicular contraction and tight junction permeability and consequently bile secretion in the postoperative period.

Effects of arachidonic and docosahexaenoic acids on secretion and degradation of bile salt-dependent lipase in AR4-2J cells

In this study we demonstrated that two polyunsaturated fatty acids, arachidonic acid (AA, n-6) and docosahexaenoic acid (DHA, n-3), modulate the secretion of bile salt-dependent lipase (BSDL) by pancreatic AR4-2J cells. The effects of AA and DHA were also compared with that of the monounsaturated fatty acid, oleic acid (OA). Our results showed that the chronic treatment of cells with AA or DHA, that did not affect the biosynthesis rate of BSDL, similarly decreased the amount of secreted BSDL and perturbed the intracellular partitioning of the enzyme, whereas OA had no effect. Particularly, AA and DHA induced the retention of the enzyme in microsomes and lowered its content in the cell cytosol. We have further shown that AA treatment decreased the ubiquitination of the protein, and consequently diminished its export toward the cytosol, a result that might explain the retention of BSDL in microsomes and correlated with membrane phospholipids alteration. The retained protein was further degraded by a nonproteasomal pathway that likely involves ATP-dependent endoplasmic reticulum proteases. These findings concerning the regulation of the pancreatic BSDL secretion by two polyunsaturated acids, AA and DHA, might be of physiological importance in the plasmatic and cellular cholesterol homeostasis.

Phosphorylation of the oncofetal variant of the human bile salt-dependent lipase. identification of phosphorylation site and relation with secretion process

In this paper, we report, for the first time, the localization of the phosphorylation site of the fetoacinar pancreatic protein (FAPP), which is an oncofetal variant of the pancreatic bile salt-dependent lipase. Using Chinese hamster ovary (CHO) cells transfected with the cDNA encoding FAPP, we radiolabeled the enzyme with (32)P, and then the protein was purified by affinity chromatography on cholate-immobilized Sepharose column and submitted to a CNBr hydrolysis. Analysis of peptides by high pressure liquid chromatography, associated with the radioactivity profile, revealed that the phosphorylation site is located at threonine 340. Site-specific mutagenesis experiments, in which the threonine was replaced by an alanine residue, were used to invalidate the phosphorylation of FAPP and to study the influence of the modification on the activity and secretion of the enzyme. These studies showed that CHO cells, transfected with the mutated cDNA of FAPP, kept all of their ability to synthesize the protein, but the loss of the phosphorylation motif prevented the release of the protein in the extracellular compartment. However, the mutated enzyme, which was sequestrated in the transfected CHO cells, remains active on bile salt-dependent lipase substrates.

Impairment of bile salt-dependent lipase secretion in AR4-2J rat pancreatic cells induces its degradation by the proteasome

Bile salt-dependent lipase (BSDL, EC 3.1.1.13) is a lipolytic enzyme normally secreted by the pancreatic acinar cell. Co- and post-translational modifications, such as N- and O-linked glycosylation, regulate the secretion of this enzyme; therefore it was of first importance to determine the behaviour of BSDL under conditions that impaired its secretion. Using AR4-2J pancreatic cells as model, we showed, particularly when BSDL secretion is impaired, that proteasome inhibitors increased the amount of intracellular BSDL, suggesting that the proteasome is involved in the degradation of this protein. This was strengthened by the detection of ubiquitinated BSDL and of degradation product. Our results suggested that both ubiquitination and degradation of the enzyme occurred at the level of the cytosolic side of microsome membranes. ATP hydrolysis appears essential in ubiquitinated BSDL association with membranes and degradation. Furthermore, under normal secretory conditions, we have shown that a fraction of ubiquitinated BSDL is neither O-glycosylated nor N-glycosylated, suggesting that the N-glycosylation-deficient proteasome substrate does not reach the Golgi and could be degraded by the ER-associated degradation machinery. However, another fraction of ubiquitinated BSDL that is deficient in O-glycosylation, carries out endoglycosidase H-insensitive N-linked glycans, meaning that a second system, that detects abnormal BSDL molecules, could also operate at the level of the Golgi compartment. Consequently, it appears that impairment of BSDL secretion consecutive to secretion inhibition or to a deficient glycosylation leads to the proteasome-ubiquitin-dependent degradation of the protein. Therefore, this pathway is part of the quality control involved in BSDL secretion.

Control of pancreatic bile-salt-dependent-lipase secretion by the glucose-regulated protein of 94 kDa (Grp94)

Bile-salt-dependent lipase (BSDL; EC 3.1.1.13) is an enzyme expressed by the pancreatic acinar cell and secreted as a component of the pancreatic juice. During its route towards secretion, BSDL is associated with intracellular membranes by means of a multiprotein folding complex, which includes the glucose-regulated protein of 94 kDa (Grp94). We have postulated that the association of BSDL with membranes is required for the complete O-glycosylation of the protein, which diverts BSDL from a degradation route and consequently allows its secretion. To further characterize the role of Grp94 in BSDL secretion, we have studied the effect of a ribozyme specifically targeted to Grp94 mRNA. This ribozyme has been transfected into AR4-2J cells, and we have shown that a decrease in Grp94 expression leads to a concomitant decrease in BSDL secretion and expression. Geldanamycin (GA), which alters Grp94 functions, also affects the release of BSDL into the culture medium of AR4-2J cells. BSDL expressed in GA-treated AR4-2J cells is unstable. Furthermore, under conditions that decrease the level of BSDL secretion, no intracellular accumulation of the enzyme was observed, suggesting that BSDL that cannot associate with (or be structured by) Grp94 could be rapidly degraded. We have further shown that this degradation probably occurs via the ubiquitin-dependent pathway. Altogether, these results indicate that Grp94 has a pivotal role in BSDL folding and in the sorting of this pancreatic enzyme.

Peritoneal colonization by human pancreatic cancer cells is inhibited by antisense FUT3 sequence

Several alpha(1,3/1,4) fucosyltransferases expressed in human pancreatic cancer cells can participate in the biosynthesis of cell surface sialyl-Lewis a and sialyl-Lewis x antigens that contribute to hematogenous metastatis. Previously, we observed a significant increase of the alpha(1,4) fucosyltransferase activity in tumoral pancreatic cell lines, suggesting that FUT3 could be involved in the sialyl-Lewis antigen expression. Therefore, we invalidated the expression of FUT3 by expressing FUT3 antisense sequence in the human pancreatic tumor BxPC-3 cell line, which expresses the alpha(1,4) fucosyltransferase activity and harbors the cell surface sialyl-Lewis antigens. The decrease of FUT3 transcript after transfection of antisense cDNA of FUT3 in these cells results in a substantial reduction of sialyl-Lewis antigen expression on cell surface. This decreased antigen expression was associated with an inhibition of adhesive properties to E-selectin and a decrease of metastatic power of FUT3 antisense-transfected BxPC-3 cells as tested in nude mice. Our study provides evidence that the expression level of FUT3 may regulate the expression of sialyl-Lewis a and sialyl-Lewis x surface antigens and consequently could play an important role in metastatic properties of human pancreatic cancer cells.

Peritoneal colonization by human pancreatic cancer cells is inhibited by antisense FUT3 sequence

Several alpha(1,3/1,4) fucosyltransferases expressed in human pancreatic cancer cells can participate in the biosynthesis of cell surface sialyl-Lewis a and sialyl-Lewis x antigens that contribute to hematogenous metastatis. Previously, we observed a significant increase of the alpha(1,4) fucosyltransferase activity in tumoral pancreatic cell lines, suggesting that FUT3 could be involved in the sialyl-Lewis antigen expression. Therefore, we invalidated the expression of FUT3 by expressing FUT3 antisense sequence in the human pancreatic tumor BxPC-3 cell line, which expresses the alpha(1,4) fucosyltransferase activity and harbors the cell surface sialyl-Lewis antigens. The decrease of FUT3 transcript after transfection of antisense cDNA of FUT3 in these cells results in a substantial reduction of sialyl-Lewis antigen expression on cell surface. This decreased antigen expression was associated with an inhibition of adhesive properties to E-selectin and a decrease of metastatic power of FUT3 antisense-transfected BxPC-3 cells as tested in nude mice. Our study provides evidence that the expression level of FUT3 may regulate the expression of sialyl-Lewis a and sialyl-Lewis x surface antigens and consequently could play an important role in metastatic properties of human pancreatic cancer cells.

Glut-1 translocation in FRTL-5 thyroid cells: role of phosphatidylinositol 3-kinase and N-glycosylation

It was previously demonstrated that insulin or TSH treatment of FRTL-5 cells resulted in an elevation of glucose transport and in an increase of cell surface expression of the glucose transporter Glut-1. However, the signaling mechanisms leading to the insulin or TSH-induced increase in the cell surface expression of Glut-1 were not investigated. In the present study, we demonstrated that wortmannin and LY294002, two specific inhibitors of phosphatidylinositol 3-kinase (PI3-kinase), interfere both in the signaling pathways of insulin and TSH leading to glucose consumption enhancement and Glut-1 translocation. Two hours after insulin treatment, TSH or cAMP analog (Bu)2cAMP stimulation, glucose transport was increased and most of the intracellular Glut-1 pool was translocated to plasma membranes. Wortmannin or LY294002 blocked the insulin, (Bu)2cAMP, and the TSH-induced translocation of Glut-1. Wortmannin or LY294002 alone did not alter the basal ratio between intracellular and cell surface Glut-1 molecules. These results suggest that in FRTL-5 cells wortmannin and LY294002 inhibited the insulin, (Bu)2cAMP and TSH events leading to Glut-1 translocation from an intracellular compartment to the plasma membrane. Likewise, (Bu)2cAMP effects on glucose transport and Glut-1 translocation to plasma membrane were repressed by PI3-kinase inhibitors but not by the protein kinase A (PKA) inhibitor H89. We suggest that (Bu)2cAMP stimulates Glut-1 translocation to plasma membrane through PI3-kinase-dependent and PKA-independent signaling pathways. To further elucidate mechanisms that regulate the translocation of Glut-1 to cell membrane, we extended this study to the role played by the N-glycosylation in the translocation and in the biological activity of Glut-1 in FRTL-5 cells. For this purpose we used tunicamycin, an inhibitor of the N-glycosylation. Our experiments with tunicamycin clearly showed that both the glycosylated and unglycosylated forms of the transporter reached the cell surface. Likewise, a decrease in glucose consumption (-50%) after treatment of cells with tunicamycin was accompanied by a decrease (-70% vs. control) in the membrane expression of a 50-kDa form of Glut-1 and an increase in its unglycosylated 41-kDa form. These results suggest that carbohydrate moiety is essential for the biological activity of glucose transport but is not required for the translocation of Glut-1 from the intracellular membrane pool to the plasma membrane.

Impairment of bile salt-dependent lipase secretion in human pancreatic tumoral SOJ-6 cells

Bile salt-dependent lipase (BSDL) was detected in human SOJ-6 and rat AR4-2J pancreatic cells. Whereas AR4-2J cells actively secreted the enzyme, BSDL was retained within the Golgi compartment of SOJ-6 cells. Because Rab6 is involved in vesicle transport in the Golgi apparatus and the trans-Golgi network, we confirmed the presence of Rab6 in these cells. In rat AR4-2J cells, Rab6 as well as Rab1A/B and Rab2, partitioned between the cytosol and microsomes. In SOJ-6 cells Rab1A/B and Rab2 also partitioned between the cytosol and microsomes, but Rab6 was strictly associated with microsome membranes, suggesting a specific defect of Rab6 cycling in human SOJ-6 cells. The apparent defect of cycling in these cells is not due to the expression of a defective Rab6 since its correct sequence was confirmed. We further demonstrated that AR4-2J and SOJ-6 cells express the Rab-GDIbeta and Rab-GDIalpha isoforms, respectively. However, the sequence of Rab-GDIbeta, which may be the main form expressed by SOJ-6 cells, identified a few substitutions located in regions that are essential for Rab-GDI function. We conclude that the deficient secretion of BSDL by SOJ-6 cells could be due to the expression of defective Rab-GDIbeta. In spite of the alterations in Rab-GDIbeta, membrane proteins such as CD71 and NHE3 were correctly localized to the cell plasma membrane of SOJ-6 cells, suggesting that two functional distinct secretory pathway coexist in pancreatic cells.

Roles of molecular chaperones in pancreatic secretion and their involvement in intestinal absorption

This review focuses on the contribution of molecular chaperones in the secretory process of digestive enzymes and their interaction with enterocytes. By using biochemistry and immunocytochemistry, we have shown that Grp94, Cpn10, Cpn60, and protein disulfide isomerase (PDI) are present all along the rough endoplasmic reticulum-Golgi-granule secretory pathway of the pancreatic acinar cells and are secreted into the acinar lumen. Two other molecular chaperones, Grp78 and the Hsp70, appear to be restricted to the rough endoplasmic reticulum and the trans-Golgi apparatus, respectively. We have found that chaperones can be associated with pancreatic enzymes along the secretory pathway. Indeed, double immunogold and immunocoprecipitation revealed an association between Cpn60 and the colipase-dependent lipase (CDL) and between Grp94 and the bile salt-dependent lipase (BSDL). These complexes are secreted into the acinar lumen and diverted to the duodenal lumen. These findings led us to investigate these enzyme-chaperone complexes in intestinal tissue. Grp94, Cpn60, and PDI are present on microvilli and on the endosomal compartment of enterocytes. Furthermore, we have shown that the Grp94-BSDL complexes are internalized by enterocytes through classical endocytosis. Upon dissociation of the BSDL-Grp94 complex in the late endosome, BSDL is transferred to the basolateral membrane. We propose that Grp94 interacts with specific receptors and/or could force the associated protein to adopt a specific conformation that allows its binding to corresponding membrane receptors and its internalization by enterocytes. These two hypotheses need not to be exclusive. The existence of such a pancreatic secretion-intestinal absorption link speaks in favor of a coordinated functional connection between these two entities, through molecular chaperones, in order to optimize intestinal activities.