Bladder reconstruction using autologous smooth muscle cell sheets grafted on a pre-vascularized capsule.

Rationale: Construction of functional vascularized three-dimensional tissues has been a longstanding objective in the field of tissue engineering. The efficacy of using a tissue expander capsule as an induced vascular bed to prefabricate functional vascularized smooth muscle tissue flaps for bladder reconstruction in a rabbit model was tested. Methods: Skin tissue expanders were inserted into the groin to induce vascularized capsule pouch formation. Smooth muscle cells and endothelial progenitor cells were harvested and cocultured to form pre-vascularized smooth muscle cell sheet. Then repeated transplantation of triple-layer cell sheet grafts onto the vascularized capsular tissue was performed at 2-day intervals to prefabricate functional vascularized smooth muscle tissue flaps. Bladder muscular wall defects were created and repaired by six-layer cell sheet graft (sheet only), capsule flap (capsule only) and vascularized capsule prelaminated with smooth muscle cell sheet (sheet plus capsule). The animals were followed for 3 months after implantation and their bladders were explanted serially. Results: Bladder capacity and compliance were maintained in sheet plus capsule group throughout the 3 months. Tissue bath stimulation demonstrated that contractile responses to carbachol and KCl among the three groups revealed a significant difference (p < 0.05). Histologically, inflammation was evident in the capsule only group at 1 month and fibrosis was observed in sheet only group at 3 months. The vessel density in capsule only and sheet plus capsule group were significantly higher than in the sheet only group at each time point (p < 0.05). Comparison of the smooth muscle content among the three groups revealed a significant difference (p < 0.05). Conclusion: These results proved that the capsule may serve as an induced vascular bed for vascularized smooth muscle tissue flap prefabrication. The prefabricated functional vascularized smooth muscle tissue flap has the potential for reliable bladder reconstruction and may create new opportunities for vascularization in 3-D tissue engineering.

Histopathologic Spectrum of Neuromuscular and Vascular Hamartoma With Special Reference to the Vasculopathic Phenomenon.

Neuromuscular and vascular hamartoma (NMVH) is an unusual lesion presenting as intestinal obstruction by stricture formation. It is characterized by a hamartomatous mass comprising haphazardly arranged mesenchymal tissue native to the intestinal mucosa and submucosa. We aimed to characterize the clinicohistopathological spectrum of NMVH in adult subjects with a search for an etiological clue. We reviewed 84 resected specimens (adult cases) of intestinal obstruction in our institute and diagnosed 4 cases with NMVH. A panel of special stains (Masson trichrome, Verhoeff-van-Gieson, and periodic acid-Schiff) and immunohistochemistry (smooth muscle actin, S100, Bcl2, CD34, vimentin, desmin, CD117, and CD3) were performed in all cases. All cases of NMVH showed characteristic hamartomatous mounds comprising haphazardly arranged smooth muscle, nerves, ganglia, vessels, and collagen with overlying mucosal ulceration. Adjacent bowel showed submucosal fibrosis, muscularis mucosae thickening, and duplication along with vasculopathy. A typical vasculopathy ("vessel-in-vessel" appearance) was seen in the submucosal and/or subserosal veins. Besides, different other forms of vasculopathic changes like obliterative venopathy and concentric myohypertrophy were also seen. One case had vasculitis and the patient died despite successful surgery. One other case was associated with lymphocytic ganglioneuronitis and granulomatous etiology. We conclude that NMVH can be multifactorial in origin although ischemia resulting from vasculopathy appears to be directly causative. The characteristic vasculopathy in the submucosal location may aid in the diagnosis of NMVH in small biopsy samples.

Construction of Pedicled Smooth Muscle Tissues by Combining the Capsule Tissue and Cell Sheet Engineering.

The survival of engineered tissue requires the formation of its own capillary network, which can anastomose with the host vasculature after transplantation. Currently, while many strategies, such as modifying the scaffold material, adding endothelial cells, or angiogenic factors, have been researched, engineered tissue implanted in vivo cannot timely access to sufficient blood supply, leading to ischemic apoptosis or shrinkage. Constructing vascularized engineered tissue with its own axial vessels and subsequent pedicled transfer is promising to solve the problem of vascularization in tissue engineering. In this study, we used the tissue expander capsule as a novel platform for vascularizing autologous smooth muscle cell (SMC) sheets and fabricating vascularized engineered tissue with its own vascular pedicle. First, we verified which time point was the most effective for constructing an axial capsule vascular bed. Second, we compared the outcome of SMC sheet transplantation onto the expander capsule and classical dorsal subcutaneous tissue, which was widely used in other studies for vascularization. Finally, we transplanted multilayered SMC sheets onto the capsule bed twice to verify the feasibility of fabricating thick pedicled engineered smooth muscle tissues. The results indicated that the axial capsule tissue could be successfully induced, and the capsule tissue 1 week after full expansion was the most vascularized. Quantitative comparisons of thickness, vessel density, and apoptosis of cell sheet grafts onto two vascular beds proved that the axial capsule vascular bed was more favorable to the growth and vascularization of transplants than classical subcutaneous tissue. Furthermore, thick vascularized smooth muscle tissues with the vascular pedicle could be constructed by multi-transplanting cell sheets onto the capsule bed. The combination of axial capsule vascular bed and cell sheet engineering may provide an efficient strategy to overcome the problem of slow or insufficient vascularization in tissue engineering.

Effects of montelukast on human nasal mucosa.

OBJECTIVE: Montelukast is a selective and orally active leukotriene D4 receptor antagonist often used in treating asthma and allergic rhinitis. Montelukast nasal spray was developed to avoid systemic adverse effects of the drug in vitro. However, the effects of montelukast on human nasal mucosa are not yet fully explored and potential nasal vascular side effects of the drug merit further exploration. First, the effects of montelukast on vasocontractile responses generated by smooth muscles in the vascular structures of human nasal mucosa were investigated directly in vitro. METHODS: This study examined the effects of montelukast on human nasal mucosa in terms of mucosa resting tension, vasoconstriction caused by 10- 6 M methoxamine as a sympathetic mimetic, and electrically induced vasoconstrictions. RESULTS: The results indicated that addition of methoxamine to the incubation medium caused the nasal mucosa to vasocontract in a dose-dependent manner. Addition of montelukast at doses of 10- 5 M or above elicited a significant vasodilation response to 10- 6 M methoxamine-induced vasoconstriction. Montelukast could not inhibit electrical field stimulation-induced spike vasoconstriction. Moreover, increase in concentration of montelukast had minimal effect on basal tension of nasal mucosa. CONCLUSIONS: The study indicated significant vasodilation on human nasal mucosa under high concentrations of montelukast with a probable α-adrenoceptor antagonism. Hence, the nasal activity of α-adrenergic agonist nasal spray for nasal obstruction may be reduced in those using concomitant (oral or local spray) montelukast.

Luminally polarized mural and vascular remodeling in ileal strictures of Crohn's disease.

Intestinal stricture, a major complication of Crohn's disease (CD), results from fibromuscular remodeling and expansion of the intestinal wall. The corresponding microanatomical alterations have not been fully described, hindering progress toward understanding their pathogenesis and devising appropriate treatments. We used tissue-specific staining and quantitative digital histomorphometry for this purpose. Serial histologic sections from 37 surgically resected ileal strictures and adjacent nonstrictured controls from patients with CD were evaluated after staining for smooth muscle actin, collagen (Sirius red), and collagen types I, III, and V. Overall mural thickening in strictures was increased 2.2 ±â€¯0.2-fold compared with nonstrictured regions of the same specimens. The muscular layer most altered was the muscularis mucosae (MM). Compared with the internal and external layers of the muscularis propria, (MP) which were expanded 1.9 ±â€¯0.2- and 1.3 ±â€¯0.1-fold, respectively, the MM was expanded 17.7 ±â€¯2.6-fold, reflecting the combined effects of architectural disarray, an 11.6 ±â€¯1.4-fold increase smooth muscle content, and elaboration of pericellular type V collagen. In contrast, the architecture of the MP was preserved and pericellular collagen was virtually absent; rather, fibrosis in this layer was limited to expansion of the intramuscular septa by collagen types I and III. The muscular arteries and veins within the strictured submucosa frequently exhibited eccentric, luminally oriented adventitial mantles comprising hyperplastic myocytes and extracellular type V collagen. We conclude that the fibromuscular remodeling which results in CD-associated ileal strictures predominantly involves the MM and submucosal vasculature in a luminally polarized fashion and suggests that mucosal-based factors may contribute to stricture pathogenesis.

Inosculation of blood vessels allows early perfusion and vitality of bladder grafts--implications for bioengineered bladder wall.

Bioengineered bladder tissue is needed for patients with neurogenic bladder disease as well as for cancer. Current technologies in bladder tissue engineering have been hampered by an inability to efficiently initiate blood supply to the graft, ultimately leading to complications that include graft contraction, ischemia, and perforation. To date, the biological mechanisms of vascularization on transplant have not been suitably investigated for urologic tissues. To better understand the mechanisms of neovascularization on bladder wall transplant, a chimeric mouse model was generated such that angiogenesis and vasculogenesis could be independently assessed in vivo. Green fluorescence protein (GFP) transgenic mice received bone marrow transplants from ß-galactosidase (LacZ) transgenic animals and then subsequent bladder wall transplants from wild-type donor mice. Before euthanization, the aorta was infused with fluorescent microbeads (fluorospheres) to identify perfused vessels. The contributions of GFP (angiogenesis) and LacZ (vasculogenesis) to the formation of CD31-expressing blood vessels within the wild-type graft were evaluated by immunohistochemistry at different time points and locations within the graft (proximal, middle, and distal) to provide a spatiotemporal analysis of neovascularization. The GFP index, a measure of angiogenic host ingrowth, was significantly higher at proximal versus mid or distal regions in animals 2-16 weeks post-transplant. However, GFP index did not increase over time in any area. Within 7 days post-transplant, perfusion of primarily wild-type, donor blood vessels in the most distal areas of the graft was observed by intraluminal fluorospheres. In addition, chimeric host-donor (GFP-wild type) blood vessels were evident in proximal areas. The contribution of vasculogenesis to vascularization of the graft was limited, as LacZ cells were not specifically associated with the endothelial cells of blood vessels, but rather found primarily in areas of inflammation. The data suggest that angiogenesis of host blood vessels into the proximal region leads to inosculation between host and donor vessels and subsequent perfusion of the graft via pre-existing graft vessels within the first week after transplant. As such, the engineering of graft blood vessels and the promotion of inosculation might prevent graft contraction, thereby potentiating the use of bioengineered bladder tissue for transplantation.

Pelvic arterial occlusive disease affects the RhoA/Rho-kinase pathway in bladder smooth muscle.

PURPOSE: We investigated the effect of pelvic arterial occlusive disease on the RhoA/Rho-kinase pathway in a rat model of chronic bladder ischemia. MATERIALS AND METHODS: Male adult Sprague Dawley® rats at age 16 weeks were divided into arterial endothelial injury and control groups. The injury group underwent balloon endothelial injury of the bilateral iliac arteries and received a 2% cholesterol diet to induce pelvic arterial occlusive disease. The control group received a regular diet. At 8 weeks cystometrograms were performed. Bladder tissue was harvested for pharmacological studies and Western blot. RESULTS: Cystometrograms showed significantly lower bladder capacity in the arterial endothelial injury group than in controls. Organ bath studies revealed significantly decreased phasic contractions induced by carbachol in bladder strips from the injury group than from controls. In controls bladder strip tonic contractions induced by carbachol were significantly decreased compared with phasic contractions. However, no significant difference was observed between phasic and tonic contractions in the injury group. The Rho-kinase inhibitor Y-27632 produced a concentration dependent decrease in tonic contractions, which was more pronounced in the injury group. Western blot showed significantly increased RhoA and Rho-kinase ß expression in the injury group. CONCLUSIONS: Our results suggest that pelvic arterial occlusive disease can affect the RhoA/Rho-kinase pathway in the bladder. This pathway might possibly be involved in the maintenance of tonic contraction and contribute to the bladder hyperactivity caused by pelvic arterial occlusive disease.

Microcirculatory perfusion shift in the gut wall layers induced by extracorporeal circulation.

OBJECTIVE: Extracorporeal circulation (ECC) is regularly applied to maintain organ perfusion during major aortic and cardiovascular surgery. During thoracoabdominal aortic repair, ECC-driven selective visceral arterial perfusion (SVP) results in changed microcirculatory perfusion (shift from the muscularis toward the mucosal small intestinal layer) in conjunction with macrohemodynamic hypoperfusion. The underlying mechanism, however, is unclear. Therefore, the aim of this study was to assess in a porcine model whether ECC itself or the hypoperfusion induced by SVP is responsible for the mucosal/muscular shift in the small intestinal wall. METHODS: A thoracoabdominal aortic approach was performed in 15 healthy pigs divided equally into three groups: group I, control; group II, thoracic aortic cross-clamping with distal aortic perfusion; and group III, thoracic aortic cross-clamping with distal aortic perfusion and SVP. Macrocirculatory and microcirculatory blood flow was assessed by transit time ultrasound volume flow measurement and fluorescent microspheres. In addition, markers for metabolism and intestinal ischemia-reperfusion injury were determined. RESULTS: ECC with a roller pump induced a significant switch from the muscularis and mucosal layer of the small intestine, even with adequate macrocirculation (mucosal/muscular perfusion ratio: group I vs II, P = .005; group I vs III, P = .0018). Furthermore, the oxygen extraction ratio increased significantly in groups II (>30%) and III (>40%) in the beginning of the ECC compared with the control (group I vs II, P = .0037; group I vs III, P = .0062). Lactate concentrations and pH values did not differ between groups I and II; but group III demonstrated a significant shifting toward a lactate-associated acidosis (lactate: group I vs III, P = .0031; pH: group I vs III, P = .0001). CONCLUSIONS: We demonstrated a significant shifting between the small intestinal gut wall layers induced by roller pump-driven ECC. The shift occurs independently of macrohemodynamics, with a significant effect on aerobic metabolism in the gut wall. Consequently, an optimal intestinal perfusion cannot be guaranteed by a roller pump; therefore, perfusion techniques need to be optimized.

[Calcium--essential for everybody]. / Wapn--niezbedny dla kazdego.

Calcium regulates majority of metabolic processes within human organism and its optimal intake decreases risk of metabolic illnesses conditioned by diet. Deficiency of calcium results in higher body max index, increase risk of insulin resistance, diabetes type 2 and osteoporosis. Diet delivering full calcium load diminished impendency of hypertension; calcium regulates tension of smooth muscles of blood vessels, limits neurotransmitters activity and also diminish hazardous activity of sodium chloride. Anticancerogenic activity of calcium results from formation insoluble bile acids and fat acids salts, and most of all, from inhibition of intestine mucosa cells hyper proliferation. Due to presence of vitamin D3, CLA, proteins and bioactive peptides emerging from them, milk is more efficient in prophylaxis of diet conditioned illnesses than calcium supplements. Efficiency of milk and dairy products in treatment of obesity, sclerosis and hypertension has been proved by DASH diet.

Observations on the survival and neovascularization of fat grafts interchanged between C57BL/6-gfp and C57BL/6 mice.

BACKGROUND: Autologous fat transplantation has become a prevalent option for soft-tissue augmentation throughout the body. However, there is still much controversy over whether the fat grafts have survived or have been replaced in the recipient sites and over how the vessels grow. METHODS: After C57BL/6-gfp mice and C57BL/6 mice were paired randomly, the inguinal fat was excised and cut into pieces with scissors, and the adipose granules, approximately 0.2 ml (0.195 g), were transplanted subcutaneously with syringes to the dorsa of the paired mice. Samples were obtained at different time intervals: 3 days, 7 days, 2 weeks, 4 weeks, 2 months, 3 months, and 4 months after transplantation. Each fat sample was weighed to evaluate the graft volume. Histology, origin, and densities of neovascularization were examined by immunohistochemical staining. RESULTS: At 4 months, there was no significant difference in either graft survival or histologic evaluation. Histologic evaluation manifested the normal physiologic process of inflammation, neovascularization, remodeling, and maturity at different time intervals. At the endpoint, the immunohistochemical staining of CD34 showed that the difference in capillary density of the fat graft-31.3 ± 3.9 capillaries/mm on the dorsa of the C57BL/6-gfp mice and 29.6 ± 3.2 capillaries/mm on the dorsa of the C57BL/6 mice-was not statistically significant. The α-smooth muscle actin staining indicated that there were neovascularized vessels in both C57BL/6-gfp and C57BL/6 fat grafts. CONCLUSIONS: Fat grafts can survive and neovascularized vessels can grow from the recipient sites. Fat transplantation is feasible and will be applied more widely if fat graft survival is improved.

Dexmedetomidine prevents alterations of intestinal microcirculation that are induced by surgical stress and pain in a novel rat model.

BACKGROUND: Anesthesia can become inadequate inadvertently or by misjudgment during surgery or emergence, and the surgical stress and pain stimulation will increase without adequate treatment. Overt stimulation may activate the sympathetic nervous system, increase the blood level of catecholamines, and lead to splanchnic arterial vasoconstriction. METHODS: We divided 30 male Wistar rats into the following 3 groups: control, surgical stress and pain (SSP), and surgical stress and pain + dexmedetomidine (SSP + Dex). The rats received midline laparotomy to exteriorize a segment of terminal ileum for microcirculation examination by a full-field laser perfusion imager and sidestream dark-field video microscope on mucosa, muscle, and Peyer patch. The inspired concentration of isoflurane was decreased from 1.2% to 0.7% in SSP and SSP + Dex groups. In the SSP + Dex group, the rats received an initial loading dose of dexmedetomidine (0.5 µg/kg) and a maintenance infusion (0.5 µg · kg(-1) · h(-1)). RESULTS: Dexmedetomidine prevented surgical stress and pain-related tachycardia and hypertension, and it attenuated the reduction of the microcirculatory blood flow intensity in intestinal mucosa (1100 ± 185 perfusion units [PU] vs 800 ± 105 PU, P = 0.001) and muscle (993 ± 208 PU vs 713 ± 92 PU, P < 0.001). Dexmedetomidine restored perfused small vessel density in intestinal mucosa and muscle. CONCLUSIONS: We established a promising rat model to investigate the effect of surgical stress and pain stimulation on the intestinal microcirculation during light anesthesia. Using this rat model, we found that dexmedetomidine can normalize global hemodynamics and prevent the alteration of intestinal microcirculation.

Dietary obesity increases NO and inhibits BKCa-mediated, endothelium-dependent dilation in rat cremaster muscle artery: association with caveolins and caveolae.

Obesity is a risk factor for hypertension and other vascular disease. The aim of this study was to examine the effect of diet-induced obesity on endothelium-dependent dilation of rat cremaster muscle arterioles. Male Sprague-Dawley rats (213 ± 1 g) were fed a cafeteria-style high-fat or control diet for 16-20 wk. Control rats weighed 558 ± 7 g compared with obese rats 762 ± 12 g (n = 52-56; P < 0.05). Diet-induced obesity had no effect on acetylcholine (ACh)-induced dilation of isolated, pressurized (70 mmHg) arterioles, but sodium nitroprusside (SNP)-induced vasodilation was enhanced. ACh-induced dilation of arterioles from control rats was abolished by a combination of the K(Ca) blockers apamin, 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34), and iberiotoxin (IBTX; all 0.1 µmol/l), with no apparent role for nitric oxide (NO). In arterioles from obese rats, however, IBTX had no effect on responses to ACh while the NO synthase (NOS)/guanylate cyclase inhibitors N(ω)-nitro-L-arginine methyl ester (L-NAME; 100 µmol/l)/1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 10 µmol/l) partially inhibited ACh-induced dilation. Furthermore, NOS activity (but not endothelial NOS expression) was increased in arteries from obese rats. L-NAME/ODQ alone or removal of the endothelium constricted arterioles from obese but not control rats. Expression of caveolin-1 and -2 oligomers (but not monomers or caveolin-3) was increased in arterioles from obese rats. The number of caveolae was reduced in the endothelium of arteries, and caveolae density was increased at the ends of smooth muscle cells from obese rats. Diet-induced obesity abolished the contribution of large-conductance Ca(2+)-activated K(+) channel to ACh-mediated endothelium-dependent dilation of rat cremaster muscle arterioles, while increasing NOS activity and inducing an NO-dependent component.

Adenosine signaling: good or bad in erectile function?

The erectile status of penile tissue is governed largely by the tone of cavernosal smooth muscle cells, which is determined by the balance of vascular relaxants and constrictors. Vascular relaxants play a key role in regulating the tone of cavernosal smooth muscle and thus the initiation and maintenance of penile erection. Early studies drew attention to the potential role of adenosine signaling in this process. However, the serendipitous discovery of the effect of sildenafil on erectile physiology drew more attention toward nitric oxide (NO) as a vasodilator in the process of penile erection, and a recently discovered, unexpected erectile phenotype of adenosine deaminase-deficient mice reemphasizes the importance of adenosine as a key regulatory of erectile status. Adenosine, like NO, is a potent and short-lived vasorelaxant that functions via cyclic nucleotide second messenger signaling to promote smooth muscle relaxation. Recent studies reviewed here show that adenosine functions to relax the corpus cavernosum and promote penile erection. Excess adenosine in penile tissue contributes to the disorder called priapism, and impaired adenosine signaling is associated with erectile dysfunction. More recent research summarized in this review reveals that adenosine functions as a key endogenous vasodilator in the initiation and maintenance of normal penile erection. This new insight highlights adenosine signaling pathways operating in penile tissue as significant therapeutic targets for the treatment of erectile disorders.

Intravenous immunoglobulins modulate neutrophil activation and vascular injury through FcγRIII and SHP-1.

RATIONALE: Intravascular neutrophil recruitment and activation are key pathogenic factors that contribute to vascular injury. Intravenous immunoglobulin (IVIG) has been shown to have a beneficial effect in systemic inflammatory disorders; however, the mechanisms underlying IVIG's inhibitory effect on neutrophil recruitment and activation are not understood. OBJECTIVE: We studied the mechanisms by which IVIG exerts protection from neutrophil-mediated acute vascular injury. METHODS AND RESULTS: We examined neutrophil behavior in response to IVIG in vivo, using real-time intravital microscopy. We found that an antibody that blocks both FcγRIII and its inhibitory receptor counterpart, FcγRIIB, abrogated the inhibitory effect of IVIG on leukocyte recruitment and heterotypic red blood cell (RBC) interactions with adherent leukocytes in wild-type mice. In the context of sickle cell disease, the blockade of both FcγRIIB and III abrogated the protective effect of IVIG on acute vaso-occlusive crisis caused by neutrophil recruitment and activation. Analysis of FcγRIIB- and FcγRIII-deficient mice revealed the predominant expression of FcγRIII on circulating neutrophils. FcγRIII mediated IVIG-triggered inhibition of leukocyte recruitment, circulating RBC capture, and enhanced Mac-1 activity, whereas FcγRIIB was dispensable. In addition, FcγRIII-induced IVIG anti-inflammatory activity in neutrophils was mediated by recruitment of Src homology 2 (SH2)-containing tyrosine phosphatase-1 (SHP-1). Indeed, the protective effect of IVIG on leukocyte recruitment and activation was abrogated in SHP-1-mutant mice. CONCLUSIONS: FcγRIII, a classic activating receptor, has an unexpected inhibitory role on neutrophil adhesion and activation via recruitment of SHP-1 in response to IVIG. Our results identify SHP-1 as a therapeutic target in neutrophil-mediated vascular injury.

Chemotherapy-related leiomyopathy: a suggested morphological explanation for the intestinal dysmotility affecting patients treated with anthracyclines.

Anthracycline, used in oncological chemotherapy, has one well-known side effect: cardiotoxicity. Another is abnormal intestinal motility such as constipation and ileus, the pathogenesis of which, to our knowledge, has not been morphologically investigated. We conducted a study in search of morphological evidence that might shed some light on the pathogenesis of the motility dysfunction. Autopsies performed between 2002 and 2007 were reviewed to select cases of children who had received anthracycline therapy for various neoplasms. The seven patients found had leukemias, lymphomas, or renal solid tumors. They all suffered from constipation or intestinal dysmotility, and no case of anthracyclin-treated neoplasia without the side effect was found in the files. Tissue samples from the heart, gastrointestinal tract, uterus, urinary bladder, and skeletal muscles were examined by light and electron microscopy. As described by others, the myocardium of all anthracycline-treated patients showed loss of myofilaments, fibrosis, mitochondrial proliferation, and pools of accumulated Z-band material. In the gastrointestinal tract and other smooth muscle-endowed organs such as muscular blood vessels, bladder and uterus, the muscularis displayed hyalinization and disorganization, including loss of myofilaments and moderate-severe fibrosis. This study illustrates changes in the smooth muscle, and that of the gastrointestinal tracts and their vessels in particular, in patients treated with anthracycline, who had experienced motility dysfunction associated with their chemotherapy, suggesting that, in addition to the heart, anthracycline may also damage smooth muscle fibers and thus be instrumental in the pathogenesis of the side effects.

Effects of in vivo lidocaine administration at the time of ischemia and reperfusion on in vitro contractility of equine jejunal smooth muscle.

OBJECTIVE: To determine whether administration of lidocaine during ischemia and reperfusion in horses results in concentrations in smooth muscle sufficient to protect against the negative consequences of ischemia-reperfusion injury on smooth muscle motility. ANIMALS: 12 horses. PROCEDURES: Artificial ischemia and reperfusion injury of jejunal segments was induced in vivo in conjunction with lidocaine treatment during ischemia (IRL) or without lidocaine treatment (IR). Isometric force performance was measured in vitro in IRL and IR smooth muscle preparations with and without additional in vitro application of lidocaine. Lidocaine concentrations in smooth muscle were determined by means of high-performance liquid chromatography. To assess the influence of lidocaine on membrane permeability, activity of creatine kinase and lactate dehydrogenase released by in vitro incubated tissues was determined biochemically. RESULTS: In vivo administration of lidocaine allowed maintenance of contractile performance after an ischemia and reperfusion injury. Basic contractility and frequency of contractions were significantly increased in IRL smooth muscle tissues in vitro. Additionally, in vitro application of lidocaine achieved further improvement of contractility of IR and IRL preparations. Only in vitro application of lidocaine was able to ameliorate membrane permeability in smooth muscle of IR and IRL preparations. Lidocaine accumulation could be measured in in vivo treated samples and serum. CONCLUSIONS AND CLINICAL RELEVANCE: In vivo lidocaine administration during ischemia and reperfusion had beneficial effects on smooth muscle motility. Initiating lidocaine treatment during surgery to treat colic in horses may improve lidocaine's prokinetic features by protecting smooth muscle from effects of ischemia and reperfusion injury.

Penile rehabilitation after prostate cancer treatment: outcomes and practical algorithm.

The number of patients diagnosed with prostate cancer was estimated to be 192,000 in 2009 according to the American Cancer Society. The prevalence of reported erectile dysfunction after radical prostatectomy has significant variance. Among the studies in which the nerve-sparing status was described, erectile function recovery adequate for sexual intercourse was achieved in 50% of patients. This article reviews the animal and human studies in this field and provides a useful penile rehabilitation algorithm.

Successful implantation of bioengineered, intrinsically innervated, human internal anal sphincter.

BACKGROUND & AIMS: To restore fecal continence, the weakened pressure of the internal anal sphincter (IAS) must be increased. We bioengineered intrinsically innervated human IAS to emulate sphincteric physiology in vitro. METHODS: We cocultured human IAS circular smooth muscle with immortomouse fetal enteric neurons. We investigated the ability of bioengineered innervated human IAS, implanted in RAG1-/- mice, to undergo neovascularization and preserve the physiology of the constituent myogenic and neuronal components. RESULTS: The implanted IAS was neovascularized in vivo; numerous blood vessels were observed with no signs of inflammation or infection. Real-time force acquisition from implanted and preimplant IAS showed distinct characteristics of IAS physiology. Features included the development of spontaneous myogenic basal tone; relaxation of 100% of basal tone in response to inhibitory neurotransmitter vasoactive intestinal peptide (VIP) and direct electrical field stimulation of the intrinsic innervation; inhibition of nitrergic and VIPergic electrical field-induced relaxation (by antagonizing nitric oxide synthesis or receptor interaction); contraction in response to cholinergic stimulation with acetylcholine; and intact electromechanical coupling (evidenced by direct response to potassium chloride). Implanted, intrinsically innervated bioengineered human IAS tissue preserved the integrity and physiology of myogenic and neuronal components. CONCLUSIONS: Intrinsically innervated human IAS bioengineered tissue can be successfully implanted in mice. This approach might be used to treat patients with fecal incontinence.

Involvement of nitric oxide in mesenteric vascular reactivity following intraperitoneal pancreatic juice in rats.

The purposes of this study were to examine the protein expressions of endothelial and inducible nitric oxide synthase (eNOS and iNOS) of the rat intestinal smooth muscle, and to elucidate the role of nitric oxide (NO) in the reactivity of the superior mesenteric artery (SMA) to vasoconstrictors following intraperitoneal (i.p.) injection of pancreatic juice. Immunohistochemistry was used to observe the protein expressions of eNOS and iNOS in the intestinal tissues 15 h after i.p. injection of pancreatic juice (1 ml/100 g body weight). To test the vascular reactiveness, SMA was isolated and perfused with Tyrode's solution at a constant flow rate of 5 ml/min. The changes in perfusion pressure as the measure of contractile responses to phenylephrine (PE) were monitored. I.P. injection of pancreatic juice induced increases of plasma levels of tumor necrosis factor α (TNFα) (P < 0.001; N = 7) and NO (P < 0.001; N = 7). Nω-nitro-L-arginine methyl ester (L-NAME) reduced the release of TNFα and NO. There were 8.3 ± 1.2-fold and 11.4 ± 2.8-fold increases in the protein expressions of eNOS and iNOS, respectively, in the intestinal tissue after pancreatic juice injection. PE (10⁻8 ~ 10⁻4 M) produced a dose-dependent vasoconstrictive effects on the SMA bed. Contractile responses to PE were attenuated in pancreatic juice-treated group. Addition of L-NAME (10⁻4 M) resulted in full recovery of the responses to phenylephrine in SMA bed, while aminoguanidine (AG, 10⁻4 M) caused only partial recovery. Our results indicate that i.p. injection of pancreatic juice results in a decrease in vascular reactivity of mesenteric vessels that is dependent on both eNOS and iNOS expressions in the intestinal vascular bed. Overproduction of NO elicits intestinal low vascular reactivity.

Drosophila EGFR pathway coordinates stem cell proliferation and gut remodeling following infection.

BACKGROUND: Gut homeostasis is central to whole organism health, and its disruption is associated with a broad range of pathologies. Following damage, complex physiological events are required in the gut to maintain proper homeostasis. Previously, we demonstrated that ingestion of a nonlethal pathogen, Erwinia carotovora carotovora 15, induces a massive increase in stem cell proliferation in the gut of Drosophila. However, the precise cellular events that occur following infection have not been quantitatively described, nor do we understand the interaction between multiple pathways that have been implicated in epithelium renewal. RESULTS: To understand the process of infection and epithelium renewal in more detail, we performed a quantitative analysis of several cellular and morphological characteristics of the gut. We observed that the gut of adult Drosophila undergoes a dynamic remodeling in response to bacterial infection. This remodeling coordinates the synthesis of new enterocytes, their proper morphogenesis and the elimination of damaged cells through delamination and anoikis. We demonstrate that one signaling pathway, the epidermal growth factor receptor (EGFR) pathway, is key to controlling each of these steps through distinct functions in intestinal stem cells and enterocytes. The EGFR pathway is activated by the EGF ligands, Spitz, Keren and Vein, the latter being induced in the surrounding visceral muscles in part under the control of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. Additionally, the EGFR pathway synergizes with the JAK/STAT pathway in stem cells to promote their proliferation. Finally, we show that the EGFR pathway contributes to gut morphogenesis through its activity in enterocytes and is required to properly coordinate the delamination and anoikis of damaged cells. This function of the EGFR pathway in enterocytes is key to maintaining homeostasis, as flies lacking EGFR are highly susceptible to infection. CONCLUSIONS: This study demonstrates that restoration of normal gut morphology following bacterial infection is a more complex phenomenon than previously described. Maintenance of gut homeostasis requires the coordination of stem cell proliferation and differentiation, with the incorporation and morphogenesis of new cells and the expulsion of damaged enterocytes. We show that one signaling pathway, the EGFR pathway, is central to all these stages, and its activation at multiple steps could synchronize the complex cellular events leading to gut repair and homeostasis.