Regional Gastrointestinal Transit Times in Patients With Carcinoid Diarrhea: Assessment With the Novel 3D-Transit System

( Tine Gregersen ),( Anne Mette Haase ),( Vincent Schlageter ),( Henning Gronbaek ),( Klaus Krogh ) 대한소화기기능성질환·운동학회 2015 Journal of Neurogastroenterology and Motility (JNM Vol.21 No.3

Background/Aims: The paucity of knowledge regarding gastrointestinal motility in patients with neuroendocrine tumors and carcinoid diarrhea restricts targeted treatment. 3D-Transit is a novel, minimally invasive, ambulatory method for description of gastrointestinal motility. The system has not yet been evaluated in any group of patients. We aimed to test the performance of 3D-Transit in patients with carcinoid diarrhea and to compare the patients`` regional gastrointestinal transit times (GITT) and colonic motility patterns with those of healthy subjects. Methods: Fifteen healthy volunteers and seven patients with neuroendocrine tumor and at least 3 bowel movements per day were investigated with 3D-Transit and standard radiopaque markers. Results: Total GITT assessed with 3D-Transit and radiopaque markers were well correlated (Spearman``s rho = 0.64, P = 0.002). Median total GITT was 12.5 (range: 8.5-47.2) hours in patients versus 25.1 (range: 13.1-142.3) hours in healthy (P = 0.007). There was no difference in gastric emptying (P = 0.778). Median small intestinal transit time was 3.8 (range: 1.4-5.5) hours in patients versus 4.4 (range: 1.8-7.2) hours in healthy subjects (P = 0.044). Median colorectal transit time was 5.2 (range: 2.9-40.1) hours in patients versus 18.1 (range: 5.0-134.0) hours in healthy subjects (P = 0.012). Median frequency of pansegmental colonic movements was 0.45 (range: 0.03-1.02) per hour in patients and 0.07 (range: 0-0.61) per hour in healthy subjects (P = 0.045). Conclusions: Three-dimensional Transit allows assessment of regional GITT in patients with diarrhea. Patients with carcinoid diarrhea have faster than normal gastrointestinal transit due to faster small intestinal and colorectal transit times. The latter is caused by an increased frequency of pansegmental colonic movements. (J Neurogastroenterol Motil 2015;21:423-432)

Rectal Mechano-sensory Function in Patients with Carcinoid Diarrhea

( Tine Gregersen ),( Christina Brock ),( Anne Mette Haase ),( Søren Laurberg ),( Asbjørn M Drewes ),( Henning Grønbæk ),( Klaus Krogh ) 대한소화기기능성질환·운동학회 2016 Journal of Neurogastroenterology and Motility (JNM Vol.22 No.2

Background/Aims In patients with neuroendocrine tumors, excessive production of serotonin and other amines may cause the carcinoid syndrome, which is mainly characterized by diarrhea and flushing. Little is known about the pathophysiology of carcinoid diarrhea. In several other groups of patients, diarrhea may be associated with rectal hypersensitivity and increased rectal tone. Therefore, the aim of the present study was to compare rectal sensitivity and compliance in patients with carcinoid diarrhea and in healthy subjects. Methods Twelve patients (6 males, aged 54-78 years, median 65 years), with carcinoid diarrhea and 19 healthy subjects (7 males, aged 50-78 years, median 61 years) were included. Rectal mechanical and heat stimulation was used for assessment of rectal mechano-sensory properties. Results Overall, 5.3% higher temperatures were needed to elicit sensory responses in patients with carcinoid diarrhea than in healthy subjects (P = 0.015). Posthoc analyses revealed that the sensory threshold to heat was 48.1 ± 3.1oC in patients vs 44.7 ± 4.7oC in healthy subjects (P = 0.041). In contrast, patients and healthy subjects showed no overall differences in rectal sensory response to mechanical distension (P = 0.731) or rectal compliance (P = 0.990). Conclusions Patients with carcinoid diarrhea have higher sensory thresholds to heat stimulation in comparison to healthy subjects, but normal rectal sensation to mechanical distension and normal compliance. Therefore, treatment of carcinoid diarrhea should aim at prolonging gastrointestinal transit and decreasing secretion, rather than modifying rectal mechano-sensory function. (J Neurogastroenterol Motil 2016;22:264-271)

What Is the Future of Impedance Planimetry in Gastroenterology?

Hans Gregersen,Kar Man Lo 대한소화기 기능성질환∙운동학회 2018 Journal of Neurogastroenterology and Motility (JNM Vol.24 No.2

The gastrointestinal (GI) tract is efficient in transporting ingested material to the site of delivery in healthy subjects. A fine balance exists between peristaltic forces, the mixing and delivery of the contents, and sensory signaling. This fine balance is easily disturbed by diseases. It is mandatory to understand the pathophysiology to enhance our understanding of GI disorders. The inaccessibility and complex nervous innervation, geometry and mechanical function of the GI tract make mechanosensory evaluation difficult. Impedance planimetry is a distension technology that assesses luminal geometry, mechanical properties including muscle dynamics, and processing of nociceptive signals from the GI tract. Since standardized models do not exist for GI muscle function in vivo, models, concepts, and terminology must be borrowed from other medical fields such as cardiac mechanophysiology. The review highlights the impedance planimetric technology, muscle dynamics assessment, and 3 applied technologies of impedance planimetry. These technologies are the multimodal probes that assesses sensory function, the functional luminal imaging probe that dynamically measures the geometry of the lumen it distends, and Fecobionics that is a simulated feces providing high-resolution measurements during defecation. The advanced muscle analysis and 3 applied technologies can enhance the quality of future interdisciplinary research for gaining more knowledge about mechanical function, sensory-motor disorders, and symptoms. This is a step in the direction of individualized treatment for GI disorders based on diagnostic subtyping. There seems to be no better alternatives to impedance planimetry, but only the functional luminal imaging probe is currently commercially available. Wider use depends on commercialization of the multimodal probe and Fecobionics.

해외근무자의 개인적 특성과 이문화적응 , 역할외 행동 및 조기귀환 의도와의 관계에 대한 연구

장영철,Gregersen, Hal,Black, J . Stewart 한국국제경영학회 2000 國際經營硏究 Vol.11 No.2

본 연구는 해외근무자들의 이문화 적응, 역할외 행동 및 조기귀환의도와 관계가 있는 개인적 특성들을 살펴 보았다. 특정 기업집단에서 파견한 관리자들을 대상으로 하여, Global Leadership Institute에서 개발한 해외근무자들의 개인적 특성 개념 및 측정항목들을 중심으로 데이터를 수집하고, 분석하였다. 그 결과는 다음과 같이 요약해 볼 수 있다. 해외근무자들의 이문화 적응은 그 구성요소에 따라 관련 개인적 특성들이 차이가 나타났다. 예컨데 일반적 적응의 경우, 문화적 유연성이 가장 유의한 관계를 보였고, 사회적 적응의 경우는 사교성과 학습지향성이 한계적이나마 관계가 있는 것으로 나타났으며, 직무적응의 경우에는 다면적 리더십과 학습지향성이 통계적으로 유의한 관계를 보였다. 한편 해외근무자의 역할외 행동은 영향력 주체에 대한 신념이 가장 유의한 개인적 특성으로 나타났고, 조기귀환의도는 협동적 갈등해소 스타일, 영향력 주체에 대한 신념이 통계적으로 유의한 관계를 갖는 것으로 나타났고, 다면적 리더십과 학습지향성은 한계적이나마 관계가 있는 것으로 나타났다. 끝으로 이러한 연구결과가 갖고 있는 한계, 시사점 및 향후 연구과제들에 대한 논의를 하였다. This study examines the expatriates' personal characteristics which may be related to their cross-cultural adjustment, extra-role behavior, and intention to leave earlier from the perspective of emphasizing individual difference. Data were collected from expatriates sent overseas from a large business group, using concepts and an instrument developed by Global Leadership Institute. Findings from this study can be summarized as follows; It was found that relevant personal characteristics vary according to the components of cross-cultural adjustment. For example, cultural flexibility is associated with general adjustment, sociability and learning orientation are marginally related to social adjustment, and multi-dimensional leadership style and learning orientation are significantly related to job adjustment. For extra-role behavior, locus of control is statistically significant factor while, for intention to leave earlier, both collaborative conflict resolution style and locus of control are statistically significant factors. In addition to these factors, although marginal, multi-dimensional leadership style and learning orientation are associated with intention to leave earlier. Implications of these findings as well as some limitations of this study were discussed.

Esophageal Acid Clearance During Random Swallowing Is Faster in Patients with Barrett`s Esophagus Than in Healthy Controls

( Christian Lottrup ),( Anne L Krarup ),( Hans Gregersen ),( Per Ejstrud ),( Asbjorn M Drewes ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2016 Journal of Neurogastroenterology and Motility (JNM Vol.22 No.4

Background/Aims Impaired esophageal acid clearance may be a contributing factor in the pathogenesis of Barrett’s esophagus. However, few studies have measured acid clearance as such in these patients. In this explorative, cross-sectional study, we aimed to compare esophageal acid clearance and swallowing rate in patients with Barrett’s esophagus to that in healthy controls. Methods A total of 26 patients with histology-confirmed Barrett’s esophagus and 12 healthy controls underwent (1) upper endoscopy, (2) an acid clearance test using a pH-impedance probe under controlled conditions including controlled and random swallowing, and (3) an ambulatory pH-impedance measurement. Results Compared with controls and when swallowing randomly, patients cleared acid 46% faster (P = 0.008). Furthermore, patients swallowed 60% more frequently (mean swallows/minute: 1.90 ± 0.74 vs 1.19 ± 0.58; P = 0.005), and acid clearance time decreased with greater random swallowing rate (P < 0.001). Swallowing rate increased with lower distal esophageal baseline impedance (P = 0.014). Ambulatory acid exposure was greater in patients (P = 0.033), but clearance times assessed from the ambulatory pHmeasurement and acid clearance test were not correlated (all P > 0.3). Conclusions More frequent swallowing and thus faster acid clearance in Barrett’s esophagus may constitute a protective reflex due to impaired mucosal integrity and possibly acid hypersensitivity. Despite these reinforced mechanisms, acid clearance ability seems to be overthrown by repeated, retrograde acid reflux, thus resulting in increased esophageal acid exposure and consequently mucosal changes.

Mechanical, thermal and swelling properties of cellulose nanocrystals/PVA nanocomposites membranes

Zaib Jahan,Muhammad Bilal Khan Niazi,Øyvind Weiby Gregersen 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.57 No.-

Cellulose nanocrystals (CNC) have strong reinforcing properties when incorporated in a compatiblepolymer matrix. The study was conducted to investigate the effect of addition of different proportions ofCNC on the mechanical, thermal and swelling properties of poly(vinyl alcohol) (PVA) nanocompositemembranes for biogas separation. The incorporation of CNC in PVA increased the crystallinity at allinvestigated relative humidities. No apparent trend is observed for mechanical properties for drymembranes (0% RH) with addition of CNC in PVA matrix. However, at 93% RH the elastic modulusincreased 25 times with addition of CNC compared to pure PVA membranes. Moreover, tensile strengthalso showed twice the values at 53% RH and 93% RH after the addition of CNC. Membranes containinghigher CNC content absorbed 9% less moisture. Swelling, thermal and mechanical properties indicate agood potential of CNC/PVA nanocomposite membranes for use in CO2 separation membranes.

Mechanical and thermal properties of carboxymethyl fibers (CMF)/PVA based nanocomposite membranes

Muhammad Bilal Khan Niazi,Zaib Jahan,Arooj Ahmed,Bushra Uzair,Ahmad Mukhtar,Øyvind Weiby Gregersen 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.90 No.-

Carboxymethylfibers (CMF) of cellulose are renewable biopolymer and have shown strong reinforcingproperties when added to a compatible polymer matrix. The objective of this study was to investigate theeffect of CMF on the mechanical, thermal and swelling properties of polyvinyl alcohol (PVA) membranes. The PVA/CMF composite membranes with different proportions of CMF ranging from 1 wt.% to 6 wt.%were prepared by solution casting method. The membranes were characterized by SEM, TGA, XRD, FTIRand mechanical testing. The results revealed that at low CMF concentration composite membranesshowed homogenous dispersion of CMF in PVA matrix. The incorporation of CMF enhanced thecrystallinity of composite membranes with increase in relative humidity (RH). Furthermore, themechanical strength and moisture uptake of PVA/CMF nanocomposite membranes were enhanced afterinclusion of CMF. TGA and DSC results revealed that the addition of CMF has no significant impact on thethermal properties. PVA/CMF nanocomposite membranes showed good potential to be applied for gasseparation application particularly for CO2 capture.

Association of STAT4 with Rheumatoid Arthritis in the Korean Population

Lee, Hye-Soon,Remmers, Elaine F.,Le, Julie M.,Kastner, Daniel L.,Bae, Sang-Cheol,Gregersen, Peter K. The Feinstein Institute for Medical Research 2007 Molecular Medicine Vol.13 No.9

Axial Movements and Length Changes of the Human Lower Esophageal Sphincter During Respiration and Distension-induced Secondary Peristalsis Using Functional Luminal Imaging Probe

( Donghua Liao ),( Christian Lottrup ),( Lotte Fynne ),( Barry P Mcmahon ),( Klaus Krogh ),( Asbjørn M Drewes ),( Jingbo Zhao ),( Hans Gregersen ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2018 Journal of Neurogastroenterology and Motility (JNM Vol.24 No.2

Background/Aims Efficient transport through the esophago-gastric junction (EGJ) requires synchronized circular and longitudinal muscle contraction of the esophagus including relaxation of the lower esophageal sphincter (LES). However, there is a scarcity of technology for measuring esophagus movements in the longitudinal (axial) direction. The aim of this study is to develop new analytical tools for dynamic evaluation of the length change and axial movement of the human LES based on the functional luminal imaging probe (FLIP) technology and to present normal signatures for the selected parameters. Methods Six healthy volunteers without hiatal hernia were included. Data were analyzed from stepwise LES distensions at 20, 30, and 40 mL bag volumes. The bag pressure and the diameter change were used for motion analysis in the LES. The cyclic bag pressure frequency was used to distinguish dynamic changes of the LES induced by respiration and secondary peristalsis. Results Cyclic fluctuations of the LES were evoked by respiration and isovolumetric distension, with phasic changes of bag pressure, diameter, length, and axial movement of the LES narrow zone. Compared to the respiration-induced LES fluctuations, peristaltic contractions increased the contraction pressure amplitude (P < 0.001), shortening (P < 0.001), axial movement (P < 0.001), and diameter change (P < 0.01) of the narrow zone. The length of the narrow zone shortened as function of the pressure increase. Conclusions FLIP can be used for evaluation of dynamic length changes and axial movement of the human LES. The method may shed light on abnormal longitudinal muscle activity in esophageal disorders. (J Neurogastroenterol Motil 2018;24:255-267)

Genetic risk factors for rheumatoid arthritis differ in caucasian and Korean populations

Lee, Hye-Soon,Korman, Benjamin D.,Le, Julie M.,Kastner, Daniel L.,Remmers, Elaine F.,Gregersen, Peter K.,Bae, Sang-Cheol Wiley Subscription Services, Inc., A Wiley Company 2009 Vol.60 No.2

<B>Objective</B><P>Recent studies have identified a number of novel rheumatoid arthritis (RA) susceptibility loci in Caucasian populations. The aim of this study was to determine whether the genetic variants at 4q27, 6q23, CCL21, TRAF1/C5, and CD40 identified in Caucasians are also associated with RA in a Korean case–control collection. We also comprehensively evaluated the genetic variation within PTPN22, a well-established autoimmune disease–associated gene.</P><B>Methods</B><P>We designed an experiment to thoroughly evaluate the PTPN22 linkage disequilibrium region, using tag single-nucleotide polymorphisms (SNPs) and disease-associated SNPs at 5 RA-associated loci recently identified in Caucasians, in 1,128 Korean patients with RA and 1,022 ethnically matched control subjects. We also resequenced the PTPN22 gene to seek novel coding variants that might be contributing to disease in this population.</P><B>Results</B><P>None of the susceptibility loci identified in Caucasian patients with RA contributed significantly to disease in Koreans. Although tag SNPs covering the PTPN22 linkage disequilibrium block were polymorphic, they did not reveal any disease association, and resequencing did not identify any new common coding region variants in this population. The 6q23 and 4q27 SNPs assayed were nonpolymorphic in this population, and the TRAF1/C5, CD40, and CCL21 SNPs did not show any evidence for association with RA in this population of Korean patients.</P><B>Conclusion</B><P>The genetic risk factors for RA are different in Caucasian and Korean patients. Although patients of different ethnic groups share the HLA region as a major genetic risk locus, most other genes shown to be significantly associated with disease in Caucasians appear not to play a role in Korean patients with RA.</P>