AIMTo study whether store-operated Ca2+ channel (SOC) is present in rat colonic smooth muscle cells.

METHODSIntracellular Ca2+ ([Ca2+]i) changes induced by thapsigargin- or caffeine-activated SOC channel were measured in enzymatically dissociated rat colonic smooth muscle cells with the fluorescent indicator Fura-2/AM.

RESULTSIn the absence of external Ca2+ , the sarco-endoplasmic reticulum Ca2+ pump inhibitor thapsigargin (1 micromol/L) and ryanodine receptor (RyR) activator caffeine both transiently elevated [Ca2+]i from (68.32 +/- 3.43) nmol/L to (240.85 +/- 12.65 ) nmol/L, (481.25 +/- 34.77) nmol/L. A subsequent reintroduction of Ca2+ into the extracellular solution resulted in [Ca2+]i further elevated to (457.55 +/- 19.80) nmol/L, (1005.93 +/- 54.62) nmol/L; (643.88 +/- 34.65) nmol/L, (920.16 +/- 43.25) nmol/L, respectively. And the elevated response was blocked by lanthanum (1 mmol/L), but was insensitive to L-type voltage calcium channels blocker verapamil and membrane depolarization.

CONCLUSIONSOC activated by store depletion are present in rat colonic smooth muscle cells. And we further prove the existence of such Ca2+ channels in excitable cells.

Animals ; Caffeine ; pharmacology ; Calcium ; metabolism ; Calcium Channels ; physiology ; Colon ; cytology ; Fura-2 ; metabolism ; Myocytes, Smooth Muscle ; drug effects ; metabolism ; Rats ; Rats, Wistar ; Thapsigargin ; pharmacology

Contraction of smooth muscle cells is triggered by an increase in cytosolic Ca(2+) upon agonist stimulation. Ca(2+) influx across the plasma membrane constitutes a major component of the agonist-induced response in smooth muscle cells. Traditionally, voltage-operated Ca(2+) channel (VOCC) is considered as the channel mediating the Ca(2+) entry. However, this view has been challenged by recent discoveries, which demonstrated that other types of ion channels, such as store-operated and/or receptor-operated Ca(2+) channels (SOCC and/or ROCC), also participate in Ca(2+) response induced by agonists in smooth muscle cells. SOCC is defined as the channel activated in response to the depletion of the internal Ca(2+) stores, an event secondary to G protein coupled receptor or receptor tyrosine kinase stimulation. The Ca(2+) flow mediated by SOCC is termed as capacitative Ca(2+) entry (CCE). Previous study from other group has demonstrated that VOCC played a predominant role in ACh-induced contraction of distal colon smooth muscle in guinea pig. However, whether SOCC participates in the agonist-induced contractile response in this particular tissue is unknown. The present study was performed to investigate the role of CCE in ACh-induced mechanical activity of distal colon smooth muscle in rats. The contractile function of the smooth muscle was assessed by measuring isometric force of isolated rat distal colon rings. We showed that both high extracellular K(+) (40 mmol/L) and ACh (5 mumol/L) evoked striking contraction of the smooth muscle. The contractile responses were almost abolished by removal of extracellular Ca(2+) with ethylene glycol-bis(2-aminoethylether)-N,N,N',N' tetraacetic acid (EGTA), suggesting a critical contribution of extracellular source of Ca(2+) to the contraction. Verapamil (5 mumol/L), an L-type VOCC blocker, significantly attenuated, but didn't completely eliminate the high K(+)- and ACh-induced contraction (74% and 41% for high K(+) and ACh, respectively), indicating that additional channels might be involved in the contractile mechanism. Furthermore, ACh only induced transient contractions in the absence of extracellular Ca(2+). Readmission of Ca(2+) into the extracellular compartment resulted in a significant and sustained increase in the tension of the smooth muscle. This response was not affected by verapamil (5 mumol/L) and Cd(2+) (5 mumol/L), both of which efficiently block VOCC at the doses. However, La(3+), a known inhibitor of SOCC, significantly suppressed the Ca(2+) readdition-induced contraction in a dose-dependent manner. On the basis of these results, we conclude that contraction of smooth muscle in the distal colon is regulated by multiple Ca(2+) channels. In addition to VOCC-mediated Ca(2+) influx, SOCC-mediated CCE participates in agonist-induced contractile response of distal colon smooth muscle in rats.
Acetylcholine ; physiology ; Animals ; Calcium ; metabolism ; Calcium Channels ; physiology ; Colon ; physiology ; Female ; Male ; Muscle Contraction ; physiology ; Muscle, Smooth ; physiology ; Myocytes, Smooth Muscle ; physiology ; Rats ; Rats, Sprague-Dawley ; Verapamil ; pharmacology

Aged ; Arsenicals ; therapeutic use ; Female ; Humans ; Leukemia, Basophilic, Acute ; drug therapy ; Oxides ; therapeutic use

The effect of bombesin (BOM) on non-cholinergic excitatory synaptic transmission of the guinea pig inferior mesenteric ganglion (IMG) was investigated by intracellular recording. Repetitive stimulation of the colon nerves (1 ms, 25 Hz, 4 s) elicited a burst of action potentials, which was followed by a long-lasting depolarization in 74.3% (52/70) of the IMG neurons. The depolarization was not blocked by nicotinic (d-tubocurarine, 100 micromol/L) and muscarinic (atropine, 1 micromol/L) antagonists, but was eliminated in a low Ca(2+)/high Mg(2+) Krebs solution, indicating that the depolarization was due to the release of non-cholinergic transmitters. Superfusing the ganglia with BOM (10 micromol/L, 1 min) induced a slow depolarization in 66.5% (109/164) neurons tested. The BOM response was not appreciably changed in low Ca(2+)/high Mg(2+) Krebs solution (n=6, P>0.05), suggesting that BOM depolarized the neurons by acting directly on the postsynaptic membrane rather than via a release of other endogenous depolarizing substances. In a total of 102 cells that exhibited late slow excitatory postsynaptic potential (ls-EPSP), superfusion of the ganglia with BOM produced a membrane depolarization in 82 neurons (80%), while the remaining 20 cells (20%) exhibited no response to BOM. In 18 neurons with ls-EPSP, 4 (22%) neurons were sensitive to both BOM and SP; 6 (33%) and 5 (28%) neurons were only sensitive to BOM and SP, respectively. The remaining 3 (17%) neurons were insensitive to both BOM and SP. Membrane resistance (Rm) had no apparent change in 47.3%, 59.5 % of the neurons tested during the ls-EPSP (n=55) and BOM depolarization (n=84), respectively, but had a marked decrease in 38.2%, 27.4%, and a marked increase in the remaining 14.5%, 13.1% of the neurons. However, when the Rm change accompanying ls-EPSP was compared with that accompanying BOM depolarization (n=20) in the same neuron, the changes in Rm were always parallel. Moreover, ls-EPSP (n=6) and BOM depolarization (n=8) were all augmented by conditioning hyperpolarization. The extrapolated values of the reversal potentials of ls-EPSP and BOM depolarization were 46.0+/-8.0 and 50.0+/-7.0 mV (n=8, P>0.05), respectively. In 14 BOM-sensitive neurons, a ls-EPSP was elicited by repetitive colon nerve stimulation. Superfusion of BOM (10 micromol/L) in these cells initially caused a large depolarization and then membrane potential gradually subsided to resting level in the continuous presence of BOM. Stimulation of the presynaptic nerves at this time failed to elicit a detecable ls-EPSP in 2 neurons and induced a much smaller one in 10 cells, while the ls-EPSP in the remaining 2 neurons was not appreciably affected. On the other hand, prolonged superfusion of BOM had no effect on the amplitude and duration of ls-EPSP in 6 BOM-insensititive neurons studied (P>0.05). The amplitude and duration of SP-induced depolarization were not altered by prolonged superfusion of BOM (n=4, P>0.05) Superfusion of tyr(4) D-phe(12) bombesin (1 micromol/L, 10 15 min), a BOM receptor antagonist, did not cause any noticeable changes in passive membrane properties nor block nicotinic f-EPSPs, but markedly suppressed (n=5) or completely abolished (n=11) BOM depolarization in all 16 neurons tested Similarly, tyr(4) D-phe(12) bombesin partially or completely antagonized the ls-EPSP in 9 out of a total of BOM sensitive neurons (n=11). The ls-EPSP elicited in the remaining two neurons was insignificantly affected by this drug. However, following 10 20 min of wash with Krebs solution the ls-EPSP was reversed. In contrast, superfusion of the ganglia with tyr(4) D-phe(12) bombesin did not change the amplitude and duration (P>0.05) of ls-EPSP in 10 BOM-insensitive cells. Similarly, the amplitude and duration of SP-induced depolarization were not appreciably affected by tyr(4) D-phe(12) bombesin (n=6, P>0.05). In conclusion, our results indicate that BOM may be another transmitter mediating the ls-EPSP in the guinea pig IMG and that there is no cross-desensitization of BOM receptors and SP receptors.
Action Potentials ; drug effects ; physiology ; Animals ; Bombesin ; pharmacology ; Electric Stimulation ; Excitatory Postsynaptic Potentials ; drug effects ; physiology ; Female ; Ganglia, Sympathetic ; drug effects ; physiology ; Guinea Pigs ; In Vitro Techniques ; Male ; Synaptic Transmission ; drug effects

OBJECTIVETo establish a novel model of lumbar disc degeneration on the early stage in the rhesus monkey using percutaneous needle puncture guided by CT.

METHODS(1) Thirteen rhesus monkeys aged from 4 to 7 years, female 7 and male 6 were selected for establishing a model of the early stage of lumbar disc degeneration. (2)13 monkeys, 91 discs were divided into 3 groups: 64 discs from L1/2 to L5/6 were percutaneous punctured with a needle 20G as experimental group and 1 disc with a needle 15G as puncture control group and 26 discs were not be punctured from L6,7 to L7-S1 as control group. (3) Lumbar disc localization for needle puncture was guided by CT. All discs were examined by MRI, the HE, Masson's trichrome, Safranine-O and immunohistochemical staining of type II collagen before disc puncture and after puncture at 4, 8 and 12 weeks.

RESULTSMRI: (1) Experimental group: Pfirmann's Grade I was shown at postoperation 4, 8 and 12 weeks; (2) Puncture control group: Grade III was shown at postoperation 4 weeks and Grade IV at 8 weeks; (3) CONTROL GROUP: Grade I was shown at postoperation 4, 8 and 12 weeks. Histological examination: (1) In experimental group, there was no any change at postoperation 4 weeks, and the cell population of the nucleus was decreased at 8 weeks and more decreased at 12 weeks in HE. (2) There was no any change at postoperation 4 weeks, the clefts among the lamellae of the annulus fibrosus (AF) were shown at 8 weeks and more wider of the clefts of AF at 12 weeks in Masson's trichrome. (3) No any change was shown at postoperation 4 weeks, proteoglycan were progressively decreased at 8 and 12 weeks in Safranine-O. (4) No statistically significant difference in positive rate was observed at 4 and 8 weeks compared with control group in immunohistochemical staining of type II collagen. There was statistical difference at 12 weeks compared with control group (P<0.05). In puncture control group postoperation 8 weeks, the morphology of cell of nucleus pulposus was not clear in HE. The wider clefts of lamellae of the AF were shown in Masson's trichrome. The proteoglycan was obviously decreased in Safranine-O. Immunohistochemical staining collagen II synthesized was decreased. In normal control group, no any change was shown at 4, 8 and 12 weeks.

CONCLUSIONSThe degeneration of lumbar intervertebral disc on the early stage could be induced by the percutaneous needle puncture (20G) to the annulus fibrosus. The assessment of disc degeneration on early stage is not shown on MRI and only confirmed by histological examination.

Animals ; Disease Models, Animal ; Female ; Intervertebral Disc ; metabolism ; pathology ; surgery ; Intervertebral Disc Displacement ; etiology ; metabolism ; pathology ; Lumbar Vertebrae ; surgery ; Macaca mulatta ; Male ; Minimally Invasive Surgical Procedures ; Random Allocation

OBJECTIVETo study the clinical effect of Chinese drugs administered by both oral intake and retention enema on inflammatory bowel diseases (IBD).

METHODSAdopting a randomized controlled design, 78 patients were assigned to three groups: 26 patients in group A treated with Chinese drugs given by both oral intake and retention enema, 27 in group B with Chinese drugs given by retention enema only, and 25 in group C with given Western medicine. The changes before and after a 30-day treatment of the patients' symptoms (including diarrhea, abdominal pain, mucous or pus-bloody stool), colonoscopic examination scores and histopathology of the colonic membrane were observed.

RESULTSGroup A showed the best outcomes in all the aspects of clinical comprehensive effectiveness. Improvements in the main symptoms, colonoscopic scores and histopathology of the colonic membrane were significantly different from those in groups B and C, respectively (P<0.05). Meanwhile comparisons between groups B and C showed insignificant differences (P>0.05); group B was better in ameliorating tenesmus (P<0.05).

CONCLUSIONThrough the use of Chinese drugs administered by both oral intake and retention enema to treat IBD, which combined external-internal therapies for both overall regulation and local management, it was confirmed that the Chinese medicine could embody the therapeutic principle of attending to both disease-diagnosis and syndrome-differentiation.

Administration, Oral ; Adult ; Colon ; drug effects ; pathology ; Colonoscopy ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; therapeutic use ; Enema ; Humans ; Inflammatory Bowel Diseases ; drug therapy ; pathology ; Middle Aged ; Treatment Outcome ; Young Adult

OBJECTIVETo investigate the infection status and epidemiological characteristics of influenza virus and respiratory syncytial virus (RSV) in influenza-like illness (ILI) of children ( ≤ 14 years) in Wuhan area from 2008 to 2012.

METHODSA total of 2854 cases of ILI patients ( ≤ 14 years) in a hospital of Wuhan were recruited in the study from July 2008 to June 2012. The sample of pharyngeal swab was collected from each patient, to extract the virus nucleic acids. Real-time fluorescent quantitation reverse transcription PCR (RT-PCR) method was applied to detect the subtypes of influenza virus and RSV, and then analyzed the time and age characteristics.

RESULTSOut of the 2854 cases, 758 (26.6%) were positive for influenza virus,including 547 (19.2%) influenza A virus positive samples and 211 (7.4%) influenza B virus positive samples. Usually, there were two peaks present in the annual curve of influenza virus, namely summer peak and winter/spring peak. The positive rate of influenza virus in 6-14 years old children (48.0%, 275/573) was significantly higher than that in 3-5 years old children (26.6%, 213/801) and that under 3 years old children (18.3%, 270/1480). The difference showed statistical significance (χ(2) = 187.432, P < 0.01). A total of 219 (7.7%) cases were positive for RSV,including 108 RSV-A positive samples and 112 RSV-B positive samples (1 co-infection). The epidemic of RSV showed an obvious seasonal pattern with peaks in autumn,winter and spring,which accounted for 96.8% (212/219) of all the cases; however, the annual incidence of RSV fluctuated greatly. The predominant subtype shifted every 2 years. RSV-B predominated during September 2008 and May 2009, December 2009 and March 2010, accounting for 76.6% (36/47) and 96.9% (62/64) respectively. RSV-A predominated during November 2010 and March 2011, September 2011 and April 2012, accounting for 92.5% (37/40) and 100.0% (48/48) respectively. With the increase of the age, the positive rate of RSV-A and RSV-B decreased gradually (RSV-A: χ(2) = 36.223, P < 0.01; RSV-B: χ(2) = 36.281, P < 0.01). The positive rates of RSV-A in children < 1,1,2,3,4,5-9 and 10-14 years old were 7.0% (26/373), 5.9% (39/662), 4.0% (18/445), 3.2% (13/406), 1.3% (3/236), 1.4% (7/517) and 0.9% (2/215) respectively; while, the positive rates of RSV-B in each age group were 6.4% (24/373), 6.0% (40/662), 4.5% (20/445), 4.4% (18/406), 1.3% (3/236), 1.0% (5/517) and 0.9% (2/215) respectively. The children aged 0-3 years old were more susceptible for RSV infection,accounting for 90.0% (197/219) of the total positive samples. During the outbreak of influenza A H1N1 in November 2009, the positive rate of RSW was 3.0% (3/100), lower than that in the same month of 2008, 2010 and 2011,which were separately 18.2% (6/33), 10.8% (10/93) and 10.0% (4/40). The difference showed statistical significance (χ(2) = 8.450, P < 0.05). During the outbreak of influenza A (H1N1) in January 2011,the positive rate of RSV was 5.7% (3/53), lower than those in the same month of 2009, 2010 and 2012, which was separately 21.7% (5/23), 28.6% (22/77) and 16.0% (8/50). The difference showed statistical significance (χ(2) = 11.233,P < 0.05). During the period of less influenza happened in September 2011, the RSV positive rate was 25.0% (10/40), higher than those in the same month of 2008, 2009 and 2010, which was separately 11.4% (4/35), 1.7% (2/118) and 0.0% (0/109). The difference showed statistical significance (χ(2) = 32.521, P < 0.01).

CONCLUSIONBoth influenza virus and RSV were important etiological agents of ILI of children in Wuhan. The characteristics of seasonal and age distributions of the two viruses were notably different; meanwhile, a certain inhibitional effect of influenza virus on RSV could be observed.

Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Influenza, Human ; epidemiology ; Male ; Orthomyxoviridae ; classification ; isolation & purification ; Respiratory Syncytial Virus Infections ; epidemiology ; Respiratory Syncytial Viruses ; classification ; isolation & purification

OBJECTIVETo determine the optimal thread pitch for an experimental cylinder implant in Ansys Work-bench Design Xplorer environment.

METHODSFinite element models of segment jaw bone with a V-shaped thread implant were created. The thread pitch (P) was set from 0.5 mm to 1.6 mm. The maximum Equivalent stresses (EQV stresses) in jaw bone and in implant were evaluated.

RESULTSUnder axial load, the amplification of maximum EQV stresses in cortical bone, cancellous bone and implant were 7.1%, 123.4% and 28.7% respectively. Under bucco-lingual load, the amplification of maximum EQV stresses in cortical bone, cancellous bone and implant were 2.8%, 28.8% and 14.9% respectively. When P exceeded 0.8 mm, the response curve curvature of maximum EQV stresses in jaw bone and in implant to P was ranged from -1 to 1.

CONCLUSIONStresses in cancellous bone are more sensitive to thread pitch than in cortical bone. Stresses in jaw bone under axial load are easier affected by thread pitch than under bucco-lingual load. Thread pitch plays a greater role in protecting dental implant under axial load than under bucco-lingual load. Thread pitch exceed 0.8 mm should be the optimal design in a cylinder implant, but oversized pitch should be avoided too.

Biomechanical Phenomena ; Computer Simulation ; Dental Implants ; Dental Prosthesis Design ; Finite Element Analysis ; Mandible ; Stress, Mechanical

OBJECTIVETo determine the jaw bone stress variation affected by cylinder implant diameter and length simultaneously in Ansys DesignXplorer module.

METHODSFinite element model of segment mandible with a cylinder implant was created. The range of the implant diameter (D) and length (L) were set from 2.5 mm to 5.0 mm and from 6.0 mm to 16.0 mm respectively. The maximum Von Mises stresses in jaw bone and sensitivity to D and L were evaluated.

RESULTSUnder axial (buccolingual) load, when one variable equaled to median, the amplification of maximum Von Mises stresses in cortical bone and cancellous bone were 44.66% (71.32%) and 51.45% (58.50%) respectively with the D increasing. The amplification of maximum Von Mises stresses in cortical bone and cancellous bone were 45.97% (21.66%) and 52.15% (37.75%) respectively with the L increasing. When D exceeded 3.7 mm and L exceeded 10.0 mm, the response curve curvatures of maximum Von Mises stresses to L and D in jaw bone ranged from -1 to 0. And the variation of the maximum Von Mises stresses in jaw bone was more sensitive to D than to L.

CONCLUSIONStresses in jaw bone under buccolingual and axial load are apt to be affected by implant diameter and length respectively. And to a cylinder implant, the diameter exceeds 3.7 mm and length exceeds 10.0 mm are optimal selections. Diameter should pay more attention to than to length for cylinder implant. Expanding the width of the jaw bone is more important than expanding the height of the jaw bone in clinical experience.

Biomechanical Phenomena ; Dental Implants ; Dental Prosthesis Design ; Finite Element Analysis ; Humans ; Mandible ; Stress, Mechanical

Adult ; Aged ; Aged, 80 and over ; China ; epidemiology ; Female ; Hemorrhagic Fevers, Viral ; epidemiology ; Hospitalization ; Humans ; Male ; Middle Aged