Michael S. Kasparek

Long-Term Quality of Life in Patients with Crohn’s Disease and Perianal Fistulas: Influence of Fecal Diversion

PurposeSymptomatic perianal fistulas impair quality of life in patients with Crohn’s disease. Fecal diversion improves symptoms but may impair quality of life. This study was designed to compare long-term quality of life in patients with Crohn’s disease with symptomatic perianal fistulas who were treated with or without fecal diversion.MethodsFrom 1996 to 2002, perianal fistulas were treated in 116 patients with Crohn’s disease. A questionnaire, including four quality of life instruments, was mailed to each patient (Short-Form General Health Survey, Gastrointestinal Quality of Life Index, Cleveland Global Quality of Life Score, Short Inflammatory Bowel Disease Questionnaire).ResultsQuestionnaires were returned by 77 of 116 patients (66 percent). Thirty-four of these patients had undergone fecal diversion, whereas 43 had not. Median follow-up was 49 (range, 18–97) months in diverted and 44 (range, 14–98) months in undiverted patients (not significant). In the diverted group, 44 percent complained of Crohn’s disease-related symptoms, which was less compared with 79 percent in undiverted patients (Pu2009<u20090.05). Diverted patients achieved 68u2009±u20091 percent of the maximum possible score on the Gastrointestinal Quality of Life Index compared with 60u2009±u20092 percent in undiverted patients (mean ± standard error of the mean; Pu2009<u20090.001); diverted patients scored better on the subscale “gastrointestinal symptoms” of the Gastrointestinal Quality of Life Index (81u2009±u20091 percent vs. 67u2009±u20092 percent; Pu2009<u20090.001). There was no difference in the Short Inflammatory Bowel Disease Questionnaire between diverted and undiverted patients except for the subscale “bowel function” (91u2009±u20092 percent vs. 76u2009±u20092 percent; Pu2009<u20090.0001). No difference in quality of life was detected by the Short-Form General Health Survey and Cleveland Global Quality of Life Score.ConclusionsIn the investigated population of patients with Crohn’s disease, quality of life seems to be similar or potentially superior in diverted patients suffering from perianal fistulas compared with undiverted patients. A diverting stoma, therefore, may improve quality of life in patients with severe perianal Crohn’s disease.

Gasotransmitters in the gastrointestinal tract

The 1990s initiated a new paradigm for cell-to-cell signal transduction via “neurotransmitters” with the discovery that a gas, nitric oxide (NO), could be released specifically from nerves and act to transmit the “neural signal” secondary to nerve stimulation. But, unlike the classic paradigm of a neurotransmitter being released extracellularly from prestored vesicles and binding to a membrane-bound receptor on the effector cell, NO is synthesized on demand from nitric oxide synthase (NOS) (rather than stored in vesicles), then released extracellularly, and diffuses across the cell membrane to act on an intracellular enzyme guanylate cyclase to transduce the primary neural signal. The recognition of carbon monoxide (CO) soon followed as a second gaseous neurotransmitter acting similarly to NO. With the recent acknowledgement of hydrogen sulfide (H2S) as the third gaseous neurotransmitter, the term “gasotransmitter” was introduced to characterize gases which act as neurally released transmitters1. NO, CO, and H2S share distinct properties, which qualify them as gasotransmitters in that they 1) are small molecules of gas; 2) are freely permeable across membranes and do not act via specific membrane receptors; 3) are synthesized endogenously and enzymatically on demand and their generation is regulated; 4) have well-defined specific functions at physiologically relevant concentrations; and 5) their cellular effects may or may not be mediated by second messengers, but these gasotransmitters have specific cellular and molecular targets. Due to their gaseous nature, NO, CO, and H2S are not stored within the cell in the classic presynaptic vesicles before they are released, but rather they are synthesized and released on demand, which distinguishes these gasotransmitters from classic neurotransmitters such as acetylcholine, norepinephrine, and even the peptide neurotransmitters. Although storage vesicles for gasotransmitters have not yet been identified, protein adducts might in theory serve as storage pools. Furthermore, presynaptic re-uptake of these released gasotransmitters, as occurs with other neurotransmitters, has not been described. Gasotransmitters are rapidly scavenged or enzymatically degraded after their release to terminate their signaling activity, with biologic half-lives on the order of seconds. An additional property shared by the three gasotransmitters is their potential systemic toxicity at supra-physiologic concentrations, which led to the recognition of these gases as air pollutants and toxins before their important in vivo functions were identified or even imagined. n nOur understanding of the wide spectrum of physiologic functions of each gasotransmitter in different organ systems continues to grow. This short review will provide an overview about the role of the three established gasotransmitters, NO, CO, and H2S, focusing primarily on the control of contractile function of the gastrointestinal (GI) tract. We will also address, albeit briefly, their involvement in other important functions, such as inflammation, ileus, pain perception, and carcinogenesis in which they act, not as neurotransmitters, but more as paracrine or even systemically active substances. The number of gasotransmitters might increase with the addition of such candidate gases as ammonia and acetaldehyde; however, because these gases have not fully met the criteria to classify them as gasotransmitters, we will focus on the three established gasotransmitters NO, CO, and H2S for the purpose of this review.

Hydrogen sulfide modulates contractile function in rat jejunum.

BACKGROUNDnEffects of hydrogen sulfide (H(2)S), a third gasotransmitter of the gut, are not well understood. The aim of this study was to determine effects/mechanisms of H(2)S action on contractile function in rat jejunal muscle.nnnMETHODSnTransmural strips of longitudinal muscle were evaluated. Response to sodium hydrosulfide (NaHS, H(2)S donor; 10(-5)-10(-3)M) was studied on spontaneous contractile activity and after precontraction (bethanechol, 3 × 10(-6)M). Atropine, propranolol, phentolamine, tetrodotoxin, capsaicin, L-N(G)-nitro arginine (L-NNA), and glibenclamide were used to determine mechanisms. L-cysteine (10(-4)-10(-2)M; substrate for H(2)S production) and aminooxyacetic acid and DL-propargylglycine (inhibitors of enzymes generating H(2)S endogenously) were used to study endogenous production. Aminooxyacetic acid, DL-propargylglycine, L-NNA, and vasoactive intestinal polypeptide (VIP) antagonist [D-p-Cl-Phe(6),Leu(17)]-VIP were used to study H(2)S release during electrical field stimulation (EFS) and interaction with VIP and nitric oxide. Immunohistofluorescence of jejunal whole mounts was performed for endogenous H(2)S-producing enzymes.nnnRESULTSnCystathionine-β-synthase and cystathionine-γ-lyase were expressed only in myenteric plexus. NaHS suppressed spontaneous and stimulated contractile activity (P < 0.01). Glibenclamide prevented some suppression by NaHS (P = 0.01) of stimulated contractile activity but did not prevent suppression of spontaneous contractile activity. Other drugs had no effect on spontaneous contractile activity but increased inhibitory effects of NaHS on spontaneous and stimulated contractile activity (P < 0.05). L-cysteine had no effects on contractile activity. Inhibitors altered basal and stimulated activity suggesting endogenous release ofxa0H(2)S.nnnCONCLUSIONSnH(2)S presumably suppresses contractile activity in jejunum by direct effects on smooth muscle. Mechanism(s) of inhibition remains unclear, because blocking known neurotransmitters enhanced H(2)S-induced suppression, while blocking adenosine triphosphate (ATP)-sensitive K(+)-channels did not block H(2)S-induced inhibition.

Hexose Transporter Expression and Function in Mouse Small Intestine: Role of Diurnal Rhythm

BackgroundExpression and function of hexose transporters vary diurnally in rat small intestine; however, this subject remains unexplored in mice.AimThe aim of the study was to investigate the diurnal expression and function of hexose transporters SGLT1, GLUT2, and GLUT5 in mouse small bowel.MethodsTwenty-four c57bl6 mice maintained in a 12-h light/dark room (6xa0am–6xa0pm) were sacrificed at 9xa0am, 3xa0pm, 9xa0pm, and 3xa0am (nu2009=u20096 each). In duodenal, jejunal, and ileal mucosa, total cellular mRNA and protein levels were quantitated by real-time PCR and semiquantitative Western blotting, respectively. The everted sleeve technique measured transporter-mediated glucose uptake at 9xa0am and 9xa0pm.ResultsmRNA expression of SGLT1, GLUT2, and GLUT5 varied diurnally in all three intestinal segments (pu2009≤u20090.03). SGLT1, GLUT2, and GLUT5 protein levels varied diurnally in duodenum and jejunum (pu2009<u20090.05) but not in ileum. Transporter-mediated glucose uptake was greater at 9xa0pm than 9xa0am (pu2009≤u20090.04) in all three segments. Vmax was greater in duodenum (10 vs 6xa0nmol/cm/s) and jejunum (8 vs 5xa0nmol/cm/s) at 9xa0pm compared to 9xa0am (pu2009=u20090.01); Km remained unchanged.SummarymRNA levels of intestinal hexose transporters varied diurnally. Protein levels peaked 6–12xa0h later during dark cycle when >70% of food intake occurred; glucose transport followed a similar pattern with increased uptake at 9xa0pm.ConclusionHexose transporter expression and function vary diurnally with nocturnal feeding patterns of mice.

Expression and function of intestinal hexose transporters after small intestinal denervation

BACKGROUNDnThe role of neural regulation in expression and function of intestinal hexose transporters is unknown. The aim of this study is to determine the role of intestinal innervation in gene expression and function of the membrane hexose transporters, SGLT1, GLUT2, and GLUT5 in the enterocyte. We hypothesize that denervation of the small intestine decreases expression of hexose transporters, which leads to decreased glucose absorption.nnnMETHODSnSix groups of Lewis rats were studied (n = 6 each) as follows: control, 1 week after sham laparotomy, 1 and 8 weeks after syngeneic (no immune rejection) orthotopic small-bowel transplantation (SBT) (SBT1 and SBT8) to induce complete extrinsic denervation, and 1 and 8 weeks after selective disruption of intrinsic neural continuity to jejunoileum by gut transection and reanastomosis (T/A1 and T/A8). All tissue was harvested between 8 AM and 10 AM. In duodenum, jejunum, and ileum, mucosal messenger RNA (mRNA) levels were quantitated by real-time polymerase chain reaction (PCR), protein by Western blotting, and transporter-mediated glucose absorption using the everted sleeve technique.nnnRESULTSnAcross the 6 groups, the relative gene expression of hexose transporter mRNA and protein levels were unchanged, and no difference in transporter-mediated glucose uptake was evident in any region. The glucose transporter affinity (K(m)) and functional transporter levels (V(max)) calculated for duodenum and jejunum showed no difference among the 6 groups.nnnCONCLUSIONnBaseline regulation of hexose transporter function is not mediated tonically by intrinsic or extrinsic neural continuity to the jejunoileum.

Age-related changes in functional NANC innervation with VIP and substance P in the jejunum of Lewis rats

Age-related changes in non-adrenergic, non-cholinergic (NANC) neurotransmission might contribute to differences in gastrointestinal motility. Our aim was to determine age-related changes in functional innervation with vasoactive intestinal polypeptide (VIP) and substance P (Sub P) in rat jejunum. We hypothesized that maturation causes changes in neurotransmission with these two neuropeptides. Longitudinal and circular jejunal muscle strips from young (3 months) and middle-aged (15 months) rats (total: 24 rats) were studied; the response to exogenous VIP and Sub P and the effect of their endogenous release from the enteric nervous system during electrical field stimulation (EFS) were evaluated. In longitudinal muscle, response to exogenous VIP and endogenously released VIP during EFS were increased in middle-aged rats, while the effect of endogenously released Sub P was decreased. In the circular muscle, the response to endogenously released VIP was increased in middle-aged rats, while the effects of exogenous VIP and endogenously released Sub P were unchanged. Response to exogenous Sub P was unaffected by maturation in both muscle layers. Spontaneous contractile activity was increased in the longitudinal and circular muscle of the older rats. In the jejunum of middle-aged rats, participation of VIP in functional NANC innervation was increased, while functional innervation with Sub P was decreased. These changes in the balance of inhibitory and excitatory neurotransmission occur during the year of maturation in rats and demonstrate an age-dependant plasticity of neuromuscular bowel function.

Long-term effects of extrinsic denervation on VIP and substance P innervation in circular muscle of rat jejunum

Intestinal denervation contributes to enteric motor dysfunction after small bowel transplantation (SBT). Our aim was to determine long-term effects of extrinsic denervation on function of nonadrenergic, noncholinergic innervation with substance P and vasoactive intestinal polypeptide (VIP). Contractile activity of jejunal circular muscle strips from six age-matched, naive control rats (NC) and eight rats 1xa0year after syngeneic SBT was studied in tissue chambers. Spontaneous contractile activity did not differ between groups. Exogenous VIP inhibited contractile activity dose-dependently to a comparable degree in both groups. The VIP antagonist ([d-p-Cl-Phe6,Leu17]-VIP) and the nitric oxide synthase inhibitor l-NG-nitro-arginine did not affect VIP-induced inhibition but increased contractile activity during electrical field stimulation (EFS) in both groups. Exogenous substance P increased contractile activity dose-dependently, greater in NC than SBT. The substance P antagonist ([d-Pro2,d-Trp7,9]-substance P) inhibited effects of exogenous substance P and decreased the excitatory EFS response. Immunohistofluorescence showed tyrosine hydroxylase staining after SBT indicating sympathetic reinnervation. In jejunal circular muscle after chronic denervation, response to exogenous substance P, but not VIP, is decreased, whereas endogenous release of both neurotransmitters is preserved. Alterations in balance of excitatory and inhibitory pathways occur despite extrinsic reinnervation and might contribute to enteric motor dysfunction after SBT.

Effect of chronic, extrinsic denervation on functional NANC innervation with vasoactive intestinal polypeptide and substance P in longitudinal muscle of rat jejunum

Abstractu2002 Intestinal denervation contributes to enteric motor dysfunction after intestinal transplantation [small bowel transplantation (SBT)]. Our aim was to determine long‐term effects of extrinsic denervation on functional non‐adrenergic, non‐cholinergic innervation with vasoactive intestinal polypeptide (VIP) and substance P. Contractile activity of jejunal longitudinal muscle from six age‐matched, naïve control rats (NC) and eight rats 1u2003year after syngeneic SBT were studied in tissue chambers. Spontaneous contractile activity did not differ between groups. Exogenous VIP inhibited contractile activity dose‐dependently in both groups, greater in NC than in SBT. The VIP antagonist ([d‐p‐Cl‐Phe6,Leu17]‐VIP) and the nitric oxide synthase inhibitor l‐NG‐nitro arginine prevented inhibition by exogenous VIP and electrical field stimulation (EFS) in both groups. Exogenous substance P increased contractile activity dose‐dependently, greater in NC than in SBT. The substance P antagonist ([d‐Pro2,d‐Trp7,9]‐substance P) inhibited effects of exogenous substance P and increased the EFS‐induced inhibitory response. Immunohistofluorescence showed staining for tyrosine hydroxylase in the jejunoileum 1u2003year after SBT suggesting sympathetic reinnervation. In rat jejunal longitudinal muscle after chronic denervation, response to exogenous VIP and substance P is decreased, while endogenous release of both neurotransmitters is preserved. These alterations in excitatory and inhibitory pathways occur despite extrinsic reinnervation and might contribute to enteric motor dysfunction after SBT.

Effects of extrinsic denervation on innervation with VIP and substance P in circular muscle of rat jejunum

Abstractu2002 Extrinsic denervation contributes to enteric motor dysfunction after small bowel transplantation (SBT). Our aim was to determine changes in nonadrenergic, noncholinergic innervation with vasoactive intestinal polypeptide (VIP) and substance P (Sub P) in rat jejunal circular muscle after SBT. Muscle strips were studied in tissue chambers from six groups of rats (nu2003≥u20036 per group): naïve controls (NC), animals 1u2003week after anaesthesia/sham celiotomy (SC‐1), and 1 and 8u2003weeks after jejunal and ileal transection/reanastomosis (TA‐1, TA‐8) and after syngeneic, orthotopic SBT (SBT‐1, SBT‐8). Response to exogenous VIP and Sub P and their endogenous release during electrical field stimulation (EFS) were studied. Exogenous VIP and Sub P caused a dose‐dependent inhibition and stimulation of mechanical activity in all groups respectively (Pu2003<u20030.05). The responses to VIP and Sub P were decreased (compared to NC) in all groups at 1 and 8u2003weeks postoperatively. The VIP antagonist ([d‐p‐Cl‐Phe6,Leu17]‐VIP) did not prevent the inhibition by exogenous VIP in any group, while the Sub P antagonist ([d‐Pro2,d‐Trp7,9]‐Sub P) prevented the effect of exogenous Sub P in NC, TA‐8 and SBT‐8 (Pu2003<u20030.05). Responses to exogenous VIP were unaffected by the nitric oxide synthase inhibitor l‐NG‐nitro arginine and precontraction of muscle strips with Sub P. Endogenous release of VIP and Sub P during EFS was preserved after SBT. In circular muscle of rat jejunum, changes in neuromuscular transmission with VIP and Sub P during the first 8u2003weeks after SBT are not mediated by extrinsic denervation.

Postoperative Complications have Little Influence on Long-term Quality of Life in Crohn's Patients

PurposeThe purpose of the study was to determine the influence of postoperative complications on long-term quality of life in patients after abdominal operations for Crohn’s disease.Materials and MethodsFrom 1996 to 2002, 305 Crohn’s patients underwent abdominal surgery, and 66 patients developed postoperative complications. Quality of life was studied using a standardized questionnaire and four quality of life instruments. Sixty-six Crohn’s patients with uneventful postoperative course matched for age, and follow-up time served as controls.ResultsForty-eight patients (81%) in the complication group (32 major and 16 minor) and 43 patients (75%) in the control group answered the questionnaire. Postoperative follow-up time was 42 (10–94) and 41xa0months (13–94; median (range)). Quality of life was comparable between groups, except on the subscale “physical functioning” of the Short-form 36 on which patients with minor and major complications showed impaired quality of life compared to controls (67u2009±u20096, 69u2009±u20094, and 84u2009±u20092%; meanu2009±u2009standard error of the mean; both pu2009<u20090.05 vs controls). The incidence of Crohn’s disease-related symptoms at follow-up was unaffected by complications (minor 63%, major 56% vs controls 70%; both not significant).ConclusionPostoperative complications after abdominal operations for Crohn’s disease do not impair long-term quality of life in general but may affect specific dimensions of quality of life like patients’ physical function.