Effects of carbamylcholine and isoproterenol on electrolyte fluxes in perfused main duct of submandibular gland of reserpinized rat

Administration of reserpine (RES) at a dosage of 0.5 mg/kg body wt, ip daily for 7 days was found to lower the dose of carbamylcholine and isoproterenol that alters sodium and potassium transport by cells of the main duct of rat submandibular gland. In the perfused main excretory duct of the submandibular gland of the RES rat, administration of carbamylcholine at a dosage of 1 microgram/kg body wt, inhibited net efflux of sodium (17%) and administration of isoproterenol at a dosage of 2 micrograms/kg body wt increased net efflux of sodium (20%); these drugs, at the same dosages, did not induce significant change in electrolyte flux of normal rat. At a dosage of 5 micrograms/kg body wt, carbamylcholine decreased net influx of potassium (15%) in the RES rat but was without effect on normal rat. Isoproterenol at the dosage of 5 micrograms/kg body wt significantly inhibited net influx of potassium in both the RES rat and normal rat. The data suggested that the duct cells developed supersensitivity to sympathomimetic and parasympathomimetic stimulation after chronic RES treatment.     

Effect of bile salt perfusion and intraduct pressure on ionic flux and mucosal ultrastructure in the pancreatic duct of the cat

Net ionic flux and mucosal ultrastructure were examined following perfusion of the cat pancreatic duct with bicarbonate or sodium taurocholate solutions (5-40 mM). Taurocholate perfusion increased net Cl- gain, net HCO3- loss and net K+ gain and was associated with significant widening of lateral intercellular spaces and increased complexity of intercellular labyrinths. Increased perfusion pressure (30 mm Hg) did not affect flux or ultrastructure during perfusion with bicarbonate but increased net ion flux significantly during perfusion with 40 mM sodium taurocholate. Ultrastructural changes during perfusion of 40 mM taurocholate at increased pressure were not consistent but focal epithelial disruption and cell shedding were seen occasionally. The hypothesis is advanced that taurocholate perfusion triggers physiological transport mechanisms and may make the duct mucosa more vulnerable to other potentially harmful agents. The significance of these changes in the pathogenesis of acute pancreatitis in man remains uncertain and care must be exercised before extrapolating from observed net ion flux data in this animal model.     

Polarized expression and function of P2Y ATP receptors in rat bile duct epithelia

Extracellular nucleotides may be important regulators of bile ductular secretion, because cholangiocytes express P2Y ATP receptors and nucleotides are found in bile. However, the expression, distribution, and function of specific P2Y receptor subtypes in cholangiocytes are unknown. Thus our aim was to determine the subtypes, distribution, and role in secretion of P2Y receptors expressed by cholangiocytes. The molecular subtypes of P2Y receptors were determined by RT-PCR. Functional studies measuring cytosolic Ca2+ (Ca) signals and bile ductular pH were performed in isolated, microperfused intrahepatic bile duct units (IBDUs). PCR products corresponding to P2Y1, P2Y2, P2Y4, P2Y6, and P2X4 receptor subtypes were identified. Luminal perfusion of ATP into IBDUs induced increases in Ca that were inhibited by apyrase and suramin. Luminal ATP, ADP, 2-methylthioadenosine 5'-triphosphate, UTP, and UDP each increased Ca. Basolateral addition of adenosine 5'-O-(3-thiotriphosphate) (ATP-gamma-S), but not ATP, to the perifusing bath increased Ca. IBDU perfusion with ATP-gamma-S induced net bile ductular alkalization. Cholangiocytes express multiple P2Y receptor subtypes that are expressed at the apical plasma membrane domain. P2Y receptors are also expressed on the basolateral domain, but their activation is attenuated by nucleotide hydrolysis. Activation of ductular P2Y receptors induces net ductular alkalization, suggesting that nucleotide signaling may be an important regulator of bile secretion by the liver.     

A net-like structure in the venous system of the late chick embryo

A net-like structure of unknown function found at the junction of the umbilical vein and the left hepatic vein of the 16-day chick embryo is described. The net consists of strands of mesenchyme tissue covered by an endothelial layer continuous with that of the blood vessels in which it is located. An unusual feature of the net is the presence, at certain points where the strands meet, of hollow spherical or ellipsoid bodies, the walls of which are formed from a layer of simple cuboidal epithelium arranged upon a well defined basal lamina. The cavity of these bodies appears to contain some non-cellular material but they have no obvious duct to their exterior. The embryological origin of the net and its possible functions are discussed.     

Role of the Accessory Parotid Gland in the Etiology of Parotitis: Statistical Analysis of Sialographic Features

This retrospective study aimed to identify if the existence of the accessory parotid gland correlated with the etiology of parotitis. This may aid the development of better treatment strategies in the future. Sialographic features of cases with parotitis and healthy subjects were reviewed. The chi-square test was used to compare the incidence of accessory parotid gland between the groups. The Student’s t test was used to compare the length of Stensen’s duct, the length from the orifice to the confluence of the accessory duct, and the angle between the accessory duct and Stensen’s duct between the groups. The incidence of accessory parotid gland in patients with parotitis was 71.8% (28/39), which was significantly higher than that in healthy subjects (P = 0.005). Patients with parotitis had a longer Stensen’s duct than healthy subjects (P = 0.003). There was no significant difference in the length from the orifice to the confluence of the accessory duct or the angle between the accessory duct and Stensen’s duct (P = 0.136 and 0.511, respectively) between the groups.The accessory parotid gland might play a role in the pathogenesis of parotitis. The existence of an accessory parotid gland is likely to interfere with salivary flow. Computational fluid dynamics analysis of salivary flow in the ductal system would be useful in future etiologic studies on parotitis.     

Unusual structure of the biliary system in the liver of the grass carp and the silver carp

It is known that the bile canaliculus in the liver of almost all vertebrates is made up of membranes of two or more adjacent liver cells. Studying the liver cell ultrastructure of lasting and fed grass carp and silver carp, it was demonstrated that a bile canaliculus is formed by deep invagination of a cell membrane of one hepatocyte. The membrane forms microvilli along the bile canaliculus. The bile canaliculus is seen in the centre of liver cell cytoplasm on the cross section and stretches from the centre of the liver cell cytoplasm to the cell membrane on the longitudinal section. The bile canaliculus is connected with a small duct cell, which is distinct from a liver cell in its small size, little amount of cell organelles and the presence of cytoplasmic filaments. The terminal part of the biliary tract consists of one liver cell and one bile duct cell. The part of the tract adjacent to the terminal one is composed of two or three small bile duct cells devoid of basal membrane. Thus, the liver parenchyma is constituted of a net of numerous bile ducts. In the portal tract, there is a large bile duct, consisting of 12-13 bile duct cells, surrounded by basal membrane and connective tissue cells.     

Intra-follicular visceral musculature in Omorgus freyi (HAAF) (Coleoptera: Trogidae) testes

The testicular follicles of the desert-adapted beetle Omorgus freyi (Haaf) (Coleoptera : Trogidae) are unusually large, relative to male size. The advance of the sperm-producing cells towards the efferent duct and, eventually, that of spermatozoa to the deferent duct, is apparently facilitated by the unique structure of these extended follicles. In contrast to the typical insect follicle, those of O. freyi and other scarabaeoid beetles have an internalized and elongated efferent duct. But, additionally, in O. freyi, the follicles are subdivided by longitudinal septa, radiating from the central efferent duct. A net of slow-supercontracting visceral muscles extends throughout the septa and efferent duct. We hypothesize that this unique structure is an adaptation maximizing reproductive potential by mobilizing large numbers of spermatozoa throughout the huge testes and transferring them to the female during the irregular short bouts of reproductive activity following the unpredictable rainfall.     

Paracrine regulation of the epithelial Na+ channel in the mammalian collecting duct by purinergic P2Y2 receptor tone

Growing evidence implicates a key role for extracellular nucleotides in cellular regulation, including of ion channels and renal function, but the mechanisms for such actions are inadequately defined. We investigated purinergic regulation of the epithelial Na+ channel (ENaC) in mammalian collecting duct. We find that ATP decreases ENaC activity in both mouse and rat collecting duct principal cells. ATP and other nucleotides, including UTP, decrease ENaC activity via apical P2Y2 receptors. ENaC in collecting ducts isolated from mice lacking this receptor have blunted responses to ATP. P2Y2 couples to ENaC via PLC; direct activation of PLC mimics ATP action. Tonic regulation of ENaC in the collecting duct occurs via locally released ATP; scavenging endogenous ATP and inhibiting P2 receptors, in the absence of other stimuli, rapidly increases ENaC activity. Moreover, ENaC has greater resting activity in collecting ducts from P2Y2-/- mice. Loss of collecting duct P2Y2 receptors in the knock-out mouse is the primary defect leading to increased ENaC activity based on the ability of direct PLC stimulation to decrease ENaC activity in collecting ducts from P2Y2-/- mice in a manner similar to ATP in collecting ducts from wild-type mice. These findings demonstrate that locally released ATP acts in an autocrine/paracrine manner to tonically regulate ENaC in mammalian collecting duct. Loss of this intrinsic regulation leads to ENaC hyperactivity and contributes to hypertension that occurs in P2Y2 receptor-/- mice. P2Y2 receptor activation by nucleotides thus provides physiologically important regulation of ENaC and electrolyte handling in mammalian kidney.     

Description of the female of Phlebotomus (Larroussius) Chadlii, Rioux, Juminer & Gibily, 1966 (Diptera: Psychodidae). From an example captured from the area of Kef (Tunisia)

The female of Phlebotomus chadlii Rioux, Jumminer & Gibily, 1966 is described and illustrated for the first time from a specimen collected in El Kef region, northwest Tunisia. It was distinguished from P. ariasi by several characters of the spermathecae: 1) the enlarged portion of P. chadlii spermathecae duct appears smooth and better developed than that of P. ariasi; 2) in P. chadlii, this part comprises three quarters of the duct whereas, in P. ariasi, it covers only the half; 3) the spermathecae neck of P. chadlii is shorter than that of P. ariasi. The duct base is compatible with the large aedeagus size of P. chadlii male. Besides, the assignment of this female to the species P. chadlii is supported by: 1) the presence of males in the same area, over the last three years; 2) the total absence in this area of P. ariasi; 3) the concomitant presence, in the same trap station, of the described female with P. chadlii males.     

L-NAME、G-CSF对急性胆道感染大鼠生存率和肺脏影响

目的 :了解大鼠在急性胆道感染时应用 L- NAME、G- csf后 ,其肺脏和生存率的影响。方法 :72只 SD大鼠随机分为 4组 ,即 :假手术组、急性胆道感染组、L- NAME处理组、G- csf处理组。采用胆总管注入大肠埃希菌 0 .2 m l(菌型 :2 5 92 2 ,浓度 4× 10 9CFU/ ml) ,双重结扎制成胆总管的急性胆道感染模型 ,观察肺组织光镜下的一般结构。 72只 SD大鼠随机分为 4组 ,分组方法如上 ,观察每组大鼠在 2 4、48、72 h的存活率。结果 :G- csf处理组与急性胆道感染组比较 ,肺脏病理损害减轻 (P<0 .0 5 ) ,存活率则显著增高 ((P<0 .0 1或 P<0 .0 5 )。L- NAME处理组肺脏病理改变有加重趋势。结论 :外源性细胞因子 L- NAME及 G- csf可影响感染中某些炎性介质的分泌和释放 ,L - NAME加重脏器损害 ,G- csf可减轻脏器损害 ,提高存活率。     

富钟瘰螈和广西瘰螈泄殖系统研究

用解剖学技术研究和比较了富钟瘰螈Paramesotriton fuzhongensis和广西瘰螈Paramesotriton guangxiensis的泄殖系统。结果显示两种瘰螈的泄殖系统基本相同,仅生殖腺在颜色和形状上稍有差异。它们具有后位肾,雄螈肾脏由副睾肾和尾肾组成。但雄螈尾肾发出的多条集尿管并不通往后位肾管而是向后汇合成副尿管通往泄殖腔。后位肾管主要起输精作用,而副尿管则负责输尿。结果揭示雄性泄殖管道有功能分离的趋势,这在两栖类中处于较高进化水平。     

Immunolocalization of androgen receptor, aromatase cytochrome P450, estrogen receptor alpha and estrogen receptor beta proteins during the breeding season in scent glands of muskrats (Ondatra zibethicus)

Aromatase cytochrome P450 (P450arom) is an enzyme that catalyzes the conversion of androgen to estrogen. Expression of P450arom in extra-gonadal sites and locally-synthesized estrogen play an important role in physiological conditions. The purpose of this study was to investigate the cellular immunolocalization of androgen receptor (AR), P450arom, estrogen receptor alpha (ERa) and estrogen receptor beta (ERβ) in muskrat scent glands during the breeding season. Histological observation and immunohistochemistry of AR, P450arom, ERa and ERβ were performed in the muskrat scent glands. In addition, total proteins were extracted from scent glandular tissues in the breeding season and were used for Western blotting analysis for AR, P450arom, ERα and ERβ. Histologically, glandular cells, interstitial cells, epithelial cells of the excretory duct and the excretory tubules were identified in the muskrat scent glands during the breeding season. AR was only observed in glandular cells of scent glands; P450arom was expressed in glandular cells and epithelial cells of the excretory duct; ERα was found in glandular cells, interstitial cells and epithelial cells of the excretory duct, whereas ERβ was present in glandular cells and epithelial cells of the excretory duct. Also, the positive signals of AR, P450arom, ERα and ERβ by Western blotting were all observed in scent glandular tissues. These results suggested that the scent gland is the target organ of androgens and estrogens, and that estrogens may play an important autocrine or paracrine role in glandular function of the muskrats.     

The effect of periphyton stoichiometry and light on biological phosphorus immobilization and release in streams

Periphyton stoichiometry can vary substantially as a result of differences in stream nutrient availability. A decrease in the periphyton carbon to phosphorus (C:P) ratio should decrease the demand for new P to be immobilized from stream water, but no studies to our knowledge have explored the relationship between periphyton stoichiometry and net P immobilization and release by periphyton. We sought to model biological P immobilization and release (flux) in streams by measuring periphyton stoichiometry and light availability. We measured P flux to and from intact periphyton on stream cobbles (20–100 mm diameter) in 1 L microcosms incubated with streamwater under variable light conditions. Net P immobilization occurred in 75% of microcosms, net P release occurred in only 5% of microcosms, and 20% of microcosms had neither net immobilization nor net release. When normalized to stream conditions, net P immobilization was highest when light availability was high (<60% canopy attenuation) and the periphyton C:P ratio was also high. In contrast, net P release occurred only when light availability was low (>60% canopy attenuation) and the periphyton C:P ratio was also low. A multiple regression model that included both periphyton stoichiometry and light availability from the growing season only, and the interaction term of these two variables, explained 99% of the variation in daily periphyton P flux observed in the study. These results indicate that in order to predict periphyton P immobilization, periphyton stoichiometry and light availability should be considered together. Furthermore, the results indicate that net P immobilization occurs even in very P-rich periphyton, which can act as a P sink when light availability is high.     

Balance—FFE序列在胆管磁共振检查中的应用

目的：探讨磁共振平衡式稳态自由进动梯度回波序列（Balance—FFE）在胆管疾病中的应用价值。方法：92例胆管病变患者均进行了冠状面的Balance—FFE序列扫描和磁共振胰胆管造影（MRCP）。将Balance-FFE的图像和3DMRCP像及MRCP原始图像对病变的显示率进行X。检验。结果：胆管系统在Balance—FFE序列中呈明显高信号,并能直接显示胆管结石和胆管狭窄,还能显示胆管外病变和胰腺病变,对周围淋巴结的显示也比较清楚。经x^2检验,Balance—FFE序列和MRCP原始像对胆管系统病变的显示没有统计学意义（P〉0．05）,而3DMRCP像对病变的显示能力不如Balance．FFE序列和MRCP原始像,对胆道病变的显示能力具有统计学意义（P〈0．05）。结论：Balance-FFE序列对胆道病变能清晰显示,成像速度快,图像信噪比高,伪影较少,与MRCP结合能提高对胆管系统病变的诊断率,因此Balance-FFE序列应作为胆管疾病磁共振扫描的常规序列,可作为MRCP序列的有效补充。     

Dispersal of fungal spores from three types of air handling system duct material

Exposure to airborne microorganisms in indoor environments may result in infectious disease or elicit an allergic or irritant response. Air handling system components contaminated by fungi have been implicated in the dispersal of spores into the indoor environment, thereby serving as a route of exposure to occupants. This study was conducted to provide quantitative data on the dispersal of spores from fungal colonies growing on three types of duct material. Galvanized metal, rigid fibrous glass ductboard, and fiberglass duct liner were soiled and contaminated with a known concentration of Penicillium chrysogenum spores. The duct materials were incubated in humidity chambers to provide a matrix of growing, sporulating fungal colonies at a contamination level of 109 colony forming units (CFU) per duct section, consistent for all materials. For each experiment a contaminated duct section was inserted into the air handling system of an experimental room, and the air handling system was operated for three 5-minute cycles with an air flow of 4.2 m3 min–1. The duct air velocity was approximately 2.8 m sec–1. The airborne concentration of culturable P. chrysogenum spores (CFU m–3), total P. chrysogenum spores (spores m–3), and total P. chrysogenum-sized particles (particles m–3) were measured in the room using Andersen single-stage impactor samplers, Burkard slide impactor samplers, and an aerodynamic particle sizer, respectively. The highest airborne concentrations (104 CFU m–3; 105 spores m–3; 104 particles m–3) were measured during the first operating cycle of the air handling system for all duct materials with decreasing airborne concentrations measured during the second and third cycles. There was no significant difference in spore dispersal from the three contaminated duct materials. These data demonstrate the potential exposure for building occupants to high concentrations of spores dispersed from fungal colonies on air handling system duct materials during normal operation of the system.     

Carbon,nitrogen and phosphorus net mineralization in organic horizons of temperate forests: stoichiometry and relations to organic matter quality

The rates of mineralization processes influence C sequestration and soil fertility, but despite their importance for ecosystem functioning, C, N and P net mineralization rates are seldom investigated together. Hence, we studied the relationships between net mineralization rates and organic matter stoichiometry in an 8-week incubation experiment with Oi, Oe and Oa horizon material of six beech, one spruce and one pine site. We determined C, N and P net mineralization rates, organic C quality and C:N:P stoichiometry. Net N mineralization only occurred below molar organic matter C:N ratios of 40 (Oi) or 28 (Oa) and N:P ratios of 42 (Oi) or 60 (Oa), and increased with decreasing C:N and N:P ratios. Net P mineralization only occurred below C:P ratios of 1400 (Oi) and N:P ratios of 40 (Oi), and increased with decreasing C:P and N:P ratios. Net N and P mineralization were strongly positively correlated with each other (r = 0.64, p < 0.001), whereas correlations of both net N and net P mineralization with C mineralization were weak. The average C:N:P stoichiometry of net mineralization was 620:4:1 (beech, Oi), 15,350:5:1 (coniferous, Oi), 1520:8:1 (Oe) and 2160:36:1 (Oa). On average, ratios of C:N net mineralization were higher, and ratios of N:P net mineralization lower than organic matter C:N and N:P ratios. This difference contributed to the decrease of C:N ratios and increase of N:P ratios from the Oi to the Oa horizons. In conclusion, the study shows that C, N and P net mineralization rates were closely correlated with the organic matter stoichiometry and that these correlations were modified by the degree of decomposition of the organic matter.     

Induction of colitis in cftr-/- mice results in bile duct injury

It is unknown why some patients with inflammatory bowel disease develop primary sclerosing cholangitis. We have recently shown that patients with primary sclerosing cholangitis have an increased prevalence of mutations in the gene responsible for cystic fibrosis (CFTR) compared with individuals with inflammatory bowel disease alone. Our aim was to examine whether induction of colitis by oral dextran leads to bile duct injury in mice heterozygous or homozygous for mutations in CFTR. The effect of oral administration of docosahexaenoic acid to correct a fatty acid imbalance associated with cystic fibrosis was also examined to determine whether this would prevent bile duct inflammation. Wild-type mice and mice heterozygous and homozygous for CFTR mutations were given dextran orally for 14 days to induce colitis. Bile duct injury was quantitated by blinded histological scoring and measurement of serum alkaline phosphatase activity. The effect of pretreatment with docosahexaenoic acid for 7 days was examined. Treatment of mice with 100 mg dextran/day for 9 days followed by 85 mg/day for 5 days resulted in a significant increase in bile duct injury as determined by histological scoring in homozygous cystic fibrosis mice compared with wild-type mice (P = 0.005). The bile duct injury seen in cystic fibrosis mice was reflected in a threefold increase in serum alkaline phosphatase (P = 0.0006). Pretreatment with oral docosahexaenoic acid decreased both histological evidence of bile duct injury and serum alkaline phosphatase levels. In the setting of colitis, loss of CFTR function leads to bile duct injury.     

中国主要五针松群落学特征及其生物量的研究

本文根据现有的文献资料,系统地分析了中国五针松的分布．群落学特征,按不同分布区、不同群落类型探讨了中国五针松的群落生物量和年净生产量及在群落的不同层次上的分布．比较分析了不同分布区五针松的年干物质累积速度（ＮＰ／Ｂ）．结果表明：１１５─１３５ａ生的阔叶红松林群落生物量在９７．０９─１２０．５１ｔ／ｈｍ￣２之间,年净生产量在８．６９８─１０．３４ｔ／ｈｍ￣２．ａ之间,年净生产量长白山山脉沙松、鹅耳枥红松林＞小兴安岭南坡枫桦、水曲柳红松林＞小兴安岭北坡云杉、冷杉红松林;３０─３６ａ生的华山松林群落生物量在７８．７５─９４．７３ｔ／ｈｍ￣２之间,年净生产量在４．９９３─５．５３７ｔ／ｈｍ￣２．ａ之间,年净生产量贵州山地常绿阔叶华山松林＞秦岭中山地阔叶华山松林＞甘肃小陇山针阔叶华山松林．ＮＰ／Ｂ值：长白山山脉的阔叶红松林＞小兴安岭山脉的阔叶红松林;秦岭中山地阔叶华山松林＞甘肃小陇山针阔华山松林＞贵州中山地常绿阔叶华山松林．     

Short- and Long-term Tannin Induced Carbon, Nitrogen and Phosphorus Dynamics in Corsican Pine Litter

Pine litter amended with either tannic acid (TA) or condensed tannins (CTs) was studied to assess the effects on C, N and P mineralization in relation to the fate of tannins by incubation experiments during various time intervals. TA induced a rapid short-term effect resulting in high C respiration and net N and P immobilisation. After one week of incubation, TA was decomposed and net C, N and P mineralization and net nitrification resembled that of the control (non-amended litter). CTs exhibited effects on net mineralization on longer terms, i.e. after several weeks of incubation until the end of the experiment (84 days). While net N and P mineralization were greatly reduced, net nitrification was only slightly affected. Most likely CTs formed complexes with organic N of the substrate thereby reducing net N mineralization, while such complexes were not involved in net nitrification processes. The reduction of net P mineralization is due to the lack of need for P by microbes when they cannot get access to N. The fact that decreasing amounts of extractable CTs were accompanied by increasing effects on mineralization processes with incubation time strongly suggests that CTs were incorporated into the litter in such a way that they were inextricable by the common solvents needed to measure tannins, such as for the Folin–Ciocalteu and HCl–butanol assays.     

诱导受体3（DcR3）在胆管癌中的表达及意义

目的：观察胆管癌组织及血清中诱导受体3（decoy receptor 3,DcR3）蛋白的表达及其临床价值。方法：采用免疫组化S-P法检测45例胆管癌、15例癌旁胆管正常组织中DcR3蛋白的表达,ELISA法检测31例胆管癌及18例胆道良性疾病患者和28例正常人外周血清中DcR3的水平。结果：45例胆管癌组织中DcR3阳性表达29例,阳性率为64.4%,胆管正常组织中无阳性表达。DcR3的表达与肿瘤临床分期、肿瘤浸润和转移有关（P〈0.05）。胆管癌患者及胆管良性疾病患者血清DcR3水平分别为152.2535.94 pg/ml,98.35 14.27 pg/ml,均高于正常人。胆管癌患者与胆道良性疾病患者血清DcR3水平相比差异有显著性（P〈0.01）。结论：DcR3在胆管癌组织中表达增高。DcR3的表达与胆管癌的发生、发展以及转移有关,可成为治疗胆管癌的一个新靶点。血清DcR3的检测对胆管癌的诊断有一定的临床价值。