Cyclic AMP dependent down regulation in the relaxation of smooth muscle cells of cat esophagitis

We investigated whether the signal mechanism for relaxation may be affected by inflammation of the cat esophagus. Acute esophagitis was induced by perfusion with 0.1N HCI at a rate of 1 mL/min for 45 min over three consecutive days. We then isolated esophageal smooth muscle cells by enzymatic digestion with collagenase. We pre-contracted the isolated smooth cells with acetylcholine (ACh) (10(-5) M) and compared the agonist-induced relaxation of pre-con tracted normal cells with those of esophagitic cells. Vasoactive intestinal polypeptide (VIP) caused a dose-dependent relaxation in normal cells, and this curve was down shifted in esophagitic cells. Sodium nitroprusside (SNP) or SIN-1 (NO donor) produced dose-dependent relaxation in normal cells, which was not affected by esophagitis. 8-Br-cGMP (a cGMP ana log) also induced dose-dependent relaxation to a similar extent in both normal and esoph agitic cells. Forskolin (a cAMP activator) or db-cAMP (a cAMP analog) produced dose-dependent relaxation in normal cells, and this relaxation curve was down shifted in esoph agitic cells. Western blotting was used to determine what subtype of adenylyl cyclase was involved in the cAMP pathway. Western blot analysis of homogenates derived from esophageal smooth muscle using antibodies against adenylyl cyclase types II, III, IV and V/VI revealed the presence of type V and/or type VI only. This result suggests that relaxation via a cAMP-dependent pathway rather than a cGMP dependent-pathway is down regulated in cat acute esophagitis. This subsensitivity of the cAMP related pathway may be related to the activ ity of adenylyl cyclase V/VI.     

Fine tuning of a reported synthetic route for biologically active flavonoid,baicalein

A modified procedure of a previous synthetic route for baicalein was developed in order to obtain more than ten grams of baicalein for in vivo test. There were several difficulties in applying the published experimental procedures for a large scale of synthesis. The modified synthetic work was successfully accomplished by reducing amount of strong Lewis acid in Fries rearrangement and using tetrabutylammonium iodide as an additive to speed up the demethylation reaction in refluxing HBr into completion.     

Pharmacokinetics of baicalein,baicalin and wogonin after oral administration of a standardized extract of<Emphasis Type="Italic">Scutellaria baicalensis</Emphasis>, PF-2405 in rats

The pharmacokinetics of active components such as baicalein, wogonin and oroxylin A were evaluated after oral administration of a purified extract of Scutellaria baicalensis GEORGI (PF-2405) containing the high contents of baicalein, wogonin and oroxylin A to rats. Following oral administration of PF-2405 at 10, 20 and 40 mg/kg dose (equivalent to 4.5, 9.0 and 18 mg/kg baicalein), a major constituent baicalein and its active metabolite baicalin showed dose-linear pharmacokinetics as evidenced by unaltered dose-normalized AUC, dose-normalized Cmax, Ae(0-30h) and GI(30h) values. Following oral administration of PF-2405 at three doses (equivalent to 0.4, 0.8 and 1.6 mg/kg wogonin), dose-normalized Cmax and dose-normalized AUC were comparable between the 20 and 40 mg/kg PF2405 doses, but plasma concentrations of wogonin at 10 mg/kg of PF-2405 were not measurable as they were below limit of quantitation (LOQ; 18 pmol/mL). Following oral administration of PF-2405 at the three doses (equivalent to 1.5, 3.0 and 6.0 mg/kg oroxylin A), the concentrations of oroxylin A in plasma, urine and gastrointestine samples were below the assay LOQ (18 pmol/mL). Significant differences in AUCs, Ae(0-30h) and GI(30h) values for baicalein and baicalin were observed after oral administration of pure baicalein (18 mg/kg) and PF-2405 (40 mg/kg). The increases in AUCs of baicalein and baicalin after oral administration of PF-2405 may have been due to the significant decrease in GO(30h) values for baicalein.     

Gene expression profiles during the activation of rat hepatic stellate cells evaluated by cDNA microarray

Hepatic stellate cells (HSCs) are activated by producing potentially injurious connective tissue components during hepatic fibrosis, thereby exerting a pivotal action in the development of liver fibrogenesis. The aim of this study was to investigate differences in gene expression patterns during the activation of HSCs using complementary cDNA microarrays. HSCs were isolated from normal rat livers and cultured for 0 (3 h), 3, 5 and 7 d. RNA was extracted from cultured cells at each point. The target RNA was hybridized to gene-specific sequence probes immobilized on chips. The hybridization signal was assessed using a confocal laser scanner. Comparison of hybridization signals and patterns allows the identification of mRNAs that are expressed differentially. Statistical analysis was used to classify and cluster the genes according to their up- or downregulation. As a result, 33 upregulated early-stage and 36 upregulated late-stage gene candidates were identified. This time-based study revealed a number of newly discovered genes involved in fibrogenesis during the activation of HSCs.     

Alfentanil attenuates phenylephrine-induced contraction in rat aorta

BACKGROUND AND OBJECTIVES: Alfentanil was reported to relax the rat aorta by direct action on the vascular smooth muscle. The aims of this in vitro study were to examine the effect of alfentanil on phenylephrine-induced contractions in the rat aorta and to determine the cellular mechanism associated with this process. METHODS: Endothelium-denuded aortic rings were suspended in order to record isometric tension. In the rings with or without 10(-6) mol naloxone or 10(-5) mol verapamil, the concentration-response curves for phenylephrine and potassium chloride were generated in the presence or absence of alfentanil (10(-6), 5 x 10(-5), 10(-4) mol). In the rings exposed to a calcium-free isotonic depolarizing solution, the contractile response induced by the addition of calcium was assessed in the presence or absence of alfentanil (5 x 10(-5), 10(-4) mol). RESULTS: Alfentanil (5 x 10(-5), 10(-4) mol) attenuated (P < 0.05) the phenylephrine-induced contraction in the ring with or without 10(-6) mol naloxone but had no effect on the phenylephrine-induced contraction in the rings pretreated with verapamil. Alfentanil (5 x 10(-5), 10(-4) mol) produced a significant rightward shift (P < 0.01) in the potassium chloride dose-response curve, and attenuated the contractile response (P < 0.001) induced by calcium in the calcium-free isotonic depolarizing solution in a dose-dependent manner. CONCLUSIONS: A supraclinical dose of alfentanil attenuates the phenylephrine-induced contraction via an inhibitory effect on calcium influx by blocking the l-type calcium channels in the rat aortic vascular smooth muscle.     

Modified Ravitch procedure: using a pectus bar for posttraumatic pectus excavatum

Guidelines for surgical management of posttraumatic pectus excavatum have not been established due to the variable clinical manifestations and limited number of cases. A 34-year-old man who was involved in a truck-mixer vehicle crash 6 months previously complained of a depressed anterior chest wall deformity. The patient had successfully undergone subperichondral resection, sternal osteotomy, and pectus bar insertion placed under the depressed sternum, followed by bar rotation for elevation of the chest wall. This case illustrates that a modified Ravitch procedure, using a pectus bar, may be an alternative for posttraumatic pectus excavatum.     

The impact of nodal isolated tumor cells on survival of breast cancer patients

BACKGROUND: Isolated tumor cells (ITCs), often detectable only with immunohistochemical techniques, have an unknown significance in the prognosis of breast cancer. The American Joint Committee on Cancer guidelines classify such patients as N0 (immunohistochemistry +), staging them with node-negative patients. We sought to further elucidate the impact of ITCs on survival. METHODS: We conducted a retrospective review of all women at our institution with breast cancer from 1996 to 2005. Of 514 patients, 16 had isolated tumor cells detected only with immunohistochemical staining. Survival then was compared with historical survival rates for women with node-free disease. RESULTS: The 16 women with N0 (i+) disease had stage I or II disease. There was no documented recurrence among these women, with an average follow-up period of 2.5 years. CONCLUSIONS: Our data suggest that ITCs detected in lymph nodes do not adversely impact survival or disease-free survival compared with women with node-negative disease. Larger studies will be required to confirm these findings.