Biomedical subjects

Z Wang

Publications and source records attributed to Z Wang.

At least 667 records · Page 37Linked to original sources

PubMed2000

A new twist in trypanosome RNA metabolism: cis-splicing of pre-mRNA.

It has been known for almost a decade and a half that in trypanosomes all mRNAs are trans-spliced by addition to the 5' end of the spliced leader (SL) sequence. During the same time period the conviction developed that classical cis-splicing introns are not present in the trypanosome genome and that the trypanosome gene arrangement is highly compact with small intergenic regions separating one gene from the next. We have now discovered that these tenets are no longer true. Poly(A) polymerase (PAP) genes in Trypanosoma brucei and Trypanosoma cruzi are split by intervening sequences of 653 and 302 nt, respectively. The intervening sequences occur at identical positions in both organisms and obey the GT/AG rule of cis-splicing introns. PAP mRNAs are trans-spliced at the very 5' end as well as internally at the 3' splice site of the intervening sequence. Interestingly, 11 nucleotide positions past the actual 5' splice site are conserved between the T. bruceiand T. cruzi introns. Point mutations in these conserved positions, as well as in the AG dinucleotide of the 3' splice site, abolish intron removal in vivo. Our results, together with the recent discovery of cis-splicing introns in Euglena gracilis, suggest that both trans- and cis-splicing are ancient acquisitions of the eukaryotic cell.

Amino Acid Sequence↗

PubMed2000

Volatile compounds produced from monosodium glutamate in common food cooking.

A mixture of soybean oil and/or water, sugar and/or monosodium glutamate (MSG) was water-boiled or oil-heated at 100, 120, 140, 160, or 170 degrees C, respectively, and volatile compounds produced were isolated by solid-phase microextraction and then identified by GC and GC/MS. Oxidative thermal degradation products of fatty acids (OTDPFA) were the major volatile compounds detected for all water-boiled samples. When MSG and sugar were heated together, 2, 5-dimethyl pyrazine and methyl pyrazine were also detected at or after 160 min heating. Water added in soybean oil increased OTDPFA production. In oil-heated samples of soybean oil alone, soybean oil with MSG, and soybean oil with sugar, OTDPFA were also the major compounds found. The samples containing MSG also produced 2-pyrrolidone, and the samples containing sugar also produced furfural and 5-hydroxy methyl furfural. The samples containing soybean oil, sugar, and MSG produced 23 pyrazines, OTDPFA, and gamma-butyrolactone as the major volatile compounds. The contents of OTDPFA were lower in MSG plus sugar and MSG-added samples, and it is postulated that antioxidant activities were produced in cooking.

Chromatography, Gas↗

PubMed2000

Impairment of gastric and jejunal myoelectrical activity during rectal distension in dogs.

It is known that distension of the rectum induces gastric hypomotility and delays gastric emptying. Its effect on gastrointestinal myoelectrical activity has not been well studied, however. The aim of this study was to investigate the effects of rectal distension on gastrointestinal myoelectrical activity in dogs. Six hound dogs implanted with electrodes on the serosa of the stomach and proximal jejunum were studied. The protocol consisted of a 30-min baseline recording and another 30-min recording during rectal distension. Gastric myoelectrical activity was severely impaired by rectal distension. The dominant power was significantly decreased from -2.79 +/- 0.52 dB at baseline to -4.84 +/- 1.26 dB during distension (P < 0.05). The percentage of normal 4-6 cycles per minute gastric slow waves was reduced from 95.08 +/- 1.11% to 83.63 +/- 4.00% (P < 0.02), and the percentage of tachygastria was increased during distension (0.33 +/- 0.19% vs 6.03 +/- 1.27%, P < 0.02). The instability coefficient of the dominant frequency was significantly increased (0.134 +/- 0.012 vs 0.326 +/- 0.074, P < 0.05). The percentage of slow wave coupling was reduced from 93.99 +/- 0.76% to 73.43 +/- 2.07% (P < 0.00003). In the small bowel, only the instability coefficient of dominant frequency showed a significant increase during distension. Other parameters were not affected by rectal distension. We conclude that rectal distension severely impairs gastric myoelectrical activity. The induced gastric dysrhythmia and reduced slow wave amplitude and coupling may be the underlying pathophysiology of gastric hypomotility and delayed gastric emptying observed during rectal distension.

Animals↗

PubMed2000

Expression of endothelin receptor subtypes and their messenger RNAs in diabetic rat prostate: effect of insulin treatment.

Streptozotocin (STZ)-induced diabetes causes an upregulation in the expression of endothelin (ET) receptors in the rat prostate (Eur J Pharmacol 310:197, 1996). We examined the effects of insulin treatment, started 8 weeks after the induction of diabetes, on the expression and distribution of ET receptors and their respective mRNAs in the rat prostate. The densities, pharmacological properties and distribution of ET receptors in the rat prostate were examined using radioligand receptor binding and autoradiographic studies, and gene expression of ET receptors was evaluated utilizing the reverse transcription-polymerase chain reaction (RT-PCR). STZ-injected rats had smaller prostates and reduced serum testosterone levels than control and insulin treated diabetic animals. ET receptor density was shown to be significantly higher in the prostate from diabetic rats than those from either control or insulin treated diabetic animals. The pharmacological profile of prostatic ET receptors was similar in all groups (approximately 80% ET(A); 20% ET(B) subtype). ET receptors were predominantly localized to the prostatic stroma. Induction of diabetes increased the expression of mRNA levels of ET(A) and ET receptors, and insulin treatment reversed this upregulation to control levels. These results indicate that (1) ET receptor subtypes are expressed in the rat prostate as transcription and translation products; (2) insulin can normalize the diabetes-induced upregulation in the expression of ET receptors and their respective mRNAs; and (3) diabetes-induced regression of the prostate may involve an alteration in ET receptors.

Animals↗

PubMed2000

Dopamine D2 receptors in the nucleus accumbens are important for social attachment in female prairie voles (Microtus ochrogaster).

The prairie vole (Microtus ochrogaster), a monogamous rodent that forms long-lasting pair bonds, has proven useful for the neurobiological study of social attachment. In the laboratory, pair bonds can be assessed by testing for a partner preference, a choice test in which pair-bonded voles regularly prefer their partner to a conspecific stranger. Studies reported here investigate the role of dopamine D2-like receptors (i.e., D2, D3, and D4 receptors) in the nucleus accumbens (NAcc) for the formation of a partner preference in female voles. Mating facilitated partner preference formation and associated with an approximately 50% increase in extracellular dopamine in the NAcc. Microinjection of the D2 antagonist eticlopride into the NAcc (but not the prelimbic cortex) blocked the formation of a partner preference in mating voles, whereas the D2 agonist quinpirole facilitated formation of a partner preference in the absence of mating. Taken together, these results suggest that D2-like receptors in the NAcc are important for the mediation of social attachments in female voles.

Animals↗

PubMed2000

Nitric oxide: a physiological mediator of the type 2 (AT2) angiotensin receptor.

Virtually all of the biological actions of angiotensin II (ANG II) have been thought to be mediated by the type 1 (AT1) angiotensin receptor and the function of the type 2 (AT2) receptor is unknown. We now describe a novel physiological action of ANG II to release nitric oxide (NO) mediated by the AT2 receptor in both the kidney and gastrointestinal tract. We present an integrated model for a counter-regulatory protective action of the AT2 receptor mediated by nitric oxide. In the kidney, ANG II at the AT2 receptor stimulates a vasodilator cascade of bradykinin (BK), NO and cyclic GMP which is tonically activated only during conditions of increased ANG II, such as sodium depletion. In the absence of the AT2 receptor, pressor and antinatriuretic hypersensitivity to ANG II is associated with BK and NO deficiency. In angiotensin-dependent hypertension, the hypotensive effect at AT1 receptor blockade is due at least in part to AT2 receptor stimulation and consequent increased activity of the vasodilator cascade. In the gastrointestinal tract, physiological quantities of ANG II stimulate the AT2 receptor releasing NO and cGMP leading to increased sodium and water absorption. In conclusion, NO is an important physiological mediator of ANG II at the AT2 receptor.

Absorption↗

PubMed2000

Cisapride provides symptomatic relief in functional dyspepsia associated with gastric myoelectrical abnormality.

OBJECTIVE: We evaluated the effects of cisapride (10 mg t.d.s. and 20 mg b.d.) on gastrointestinal symptoms and gastric myoelectrical activity in patients with functional dyspepsia. Myoelectrical activity was measured by electrogastrography. METHODS: Patients with functional dyspepsia, defined as discomfort in the epigastrium, a negative endoscopy, and clinical symptoms of dyspepsia, were enrolled. A total of 38 patients participated in the study (23 female; 15 male; 24-72 years of age). Screening electrogastrography identified those with a normal electrogastrogram (14 subjects) and those with an abnormal electrogastrogram (24 patients). Patients were randomly assigned to 2 weeks of placebo or 2 weeks of cisapride (10 mg t.d.s.); both groups then received 2 weeks of cisapride (20 mg b.d.). Electrogastrograms were repeated at the end of each 2-week treatment period. RESULTS: Cisapride 10 mg t.d.s. significantly improved symptoms in all patients. An additional 2 weeks of treatment with cisapride 20 mg b.d. led to continued improvement in symptoms in all patients, with significant improvement in the group with abnormal baseline electrogastrograms. Cisapride significantly improved postprandial bloating and discomfort in patients with abnormal baseline electrogastrograms. Cisapride also significantly improved postprandial gastric myoelectrical activity as measured by electrogastrography in patients with abnormal baseline electrogastrograms. CONCLUSION: Cisapride provides symptomatic relief and improves gastric myoelectrical abnormalities in patients with functional dyspepsia.

Adult↗

PubMed2000

Vasopressin (V1a) receptor binding, mRNA expression and transcriptional regulation by androgen in the Syrian hamster brain.

Arginine vasopressin plays an important role in the regulation of social behaviours in rodents. In the Syrian hamster, vasopressin injected directly into the brain stimulates scent marking and aggressive behaviour in a steroid dependent manner and is therefore a useful model for investigating steroid-peptide-behaviour interactions. In this study, we used in situ hybridization and radioligand binding assays on adjacent sections of hamster brains to compare the relative distribution of vasopressin (V1a) receptor mRNA and V1a receptor binding. V1a receptor mRNA and binding are abundant in the lateral septum, bed nucleus of the stria terminalis, medial preoptic nucleus, anterodorsal thalamus and suprachiasmatic nucleus. Moderate receptor binding and low levels of receptor mRNA are present in the central nucleus of the amygdala and a lateral zone from the medial preoptic area through the anterior hypothalamus. V1a receptor mRNA is anatomically more restricted in several areas compared to the ligand binding pattern, which is consistent with significant spread of receptor protein along neuronal processes. Comparison of V1a receptor ligand binding and mRNA in intact, castrated, and castrated-testosterone treated animals reveals that V1a receptors in the medial preoptic nucleus are regulated by androgen, most likely by an upregulation of V1a receptor gene expression in a cluster of neurones concentrated in the ventromedial part of this nucleus. This study confirms the presence of the V1a subtype of vasopressin receptors in behaviourally important regions of the hamster brain and suggests that transcriptional regulation by gonadal steroids may play a role in modulating behavioural sensitivity to vasopressin.

Amygdala↗

PubMed2000

Costimulatory signal through CD86 is important in Th2 response in Trichinella spiralis infected mice.

In order to study the role of the costimulatory signals in Th2 cytokine production, monoclonal antibodies (mAbs) against cell adhesion molecules (CAMs) were added to cultured cells obtained from the mesenteric lymph nodes (MLNs) of mice infected with Trichinella spiralis, followed by a determination of interleukin (IL)-5 and IL-4 in the culture supernatant. IL-5 production by MLN cells stimulated with somatic antigen was significantly reduced by addition of anti-CD86 but not by anti-CD80 mAb. Combination of anti-CD80 and anti-CD86 mAbs reduced IL-5 production most effectively. IL-4 production induced by anti-CD3 mAb was suppressed only by the addition of anti-CD86 mAb. Blockade of the ICAM-1/LFA-1 and VCAM-1/VLA-4 interactions was less effective on the production of IL-5 and IL-4 than the addition of anti-CD86 mAb alone. In contrast to the in vitro cytokine production, intraperitoneal injection of anti-CD80, anti-CD86 mAb, or both, similarly suppressed the peak of the eosinophilia on day 21. Elevation of somatic antigen-specific IgE and IgG1 levels as well as total IgE was not inhibited by the administration of anti-CD80, anti-CD86 mAb or both. In-vitro and in-vivo effects of CTLA-4 immunoglobulin were similar to those of combined treatment with anti-CD80 and anti-CD86 mAbs. These results suggest that the interaction between antigen-presenting cells and CD4 T cells through CD86 are most important in Th2 response during T. spiralis infection.

Animals↗

PubMed2000

Evidence of a functional role for the cyclin-dependent kinase inhibitor p21CIP1 in leukemic cell (U937) differentiation induced by low concentrations of 1-beta-D-arabinofuranosylcytosine.

The functional role of the cyclin-dependent kinase inhibitor (CDKI) p21CIP1 in differentiation of human myelomonocytic leukemia cells (U937) exposed to low concentrations of the antimetabolite 1-beta-D-arabino-furanosylcytosine (ara-C) was examined utilizing a cell line stably expressing a p21CIP1 antisense construct. Continuous exposure to 50 nM ara-C led to marked induction of p21CIP1 at 48-72 h in empty-vector control cells but not in their antisense-expressing counterparts (p21AS/F4 and B8). Such treatment induced expression of the myelomonocytic differentiation marker CD11b in approximately 35% of control cells, but no evidence of maturation was noted in antisense-expressing lines. However, antisense-expressing cells exposed to low concentrations of ara-C exhibited a reciprocal increase in apoptosis, manifested by the appearance of cells with classic morphologic features and hypodiploid quantities of DNA, reduced mitochondrial membrane potential (deltapsim), an increase in cytochrome c release into the cytosol, cleavage/activation of procaspases-9 and -3, and degradation of PARP and p27Kip1. Whereas empty-vector control cells exposed to 50 nM ara-C exhibited a decline in Bcl-2 expression, dephosphorylation of pRb, and an initial accumulation in S-phase, antisense-expressing cells did not. However, c-Myc down-regulation induced by low concentrations of ara-C was, if anything, more complete in antisense-expressing cells. Exposure of control but not antisense-expressing cells to ara-C led to phosphorylation/activation of MAP kinase at 24 h; moreover, the specific MEK/MAP kinase inhibitor PD98059 enhanced low-dose ara-C-mediated apoptosis only in wild-type cells. Lastly, exposure to 50 nM ara-C for 72 h resulted in detectable levels of cytoplasmic p21CIP1, a phenomenon associated with resistance to apoptosis, only in empty vector controls. Collectively, these findings demonstrate a functional role for p21CIP1 in leukemic cell maturation induced by low concentrations of ara-C. They also indicate that, as in the case of more conventional differentiation-inducers such as phorbol esters, disruption of the p21CIP1 response after exposure to low concentrations of the cytotoxic drug ara-C prevents leukemic cells from engaging a maturation program, but instead directs them along an apoptotic pathway.

Apoptosis↗

PubMed2000

Expression and localization of basic fibroblast growth factor in diabetic rat prostate.

OBJECTIVE: To assess fibroblast growth factor-2 (FGF2/bFGF), which is important in the development and maintenance of the normal prostate and in the development of human benign prostatic hyperplasia (BPH) and prostatic carcinoma, in an animal model of experimentally induced diabetes. Materials and methods Using Western blotting and immunohistochemical analyses, the expression of FGF2 in prostates from several groups of rats was investigated. Rats had diabetes for 8 or 16 weeks (induced by intravenous injection with 65 mg/kg streptozotocin); rats were also treated with insulin (starting 8 weeks after the induction of diabetes, for 8 weeks), and two further groups acted as age-matched control rats. Immunohistochemical markers for smooth muscle (alpha-actin) and epithelium (cytokeratin) were used to distinguish different cell types in adjacent prostatic sections. RESULTS: Diabetic rats had smaller prostates and lower serum testosterone levels than their controls; insulin treatment of diabetic rats increased prostatic size and testosterone levels. As shown by Western blotting, diabetes caused greater FGF2 expression than in controls, whereas reverse-transcriptase polymerase chain reaction studies showed similar levels of prostatic FGF-2 mRNA in all groups. Immuno-histochemical studies showed that FGF-2 was expressed in both stromal and epithelial components of the rat prostate. Furthermore, although the expression of FGF2 was higher in epithelial than stromal cells in control prostates, it was distributed uniformly in the diabetic prostate. CONCLUSION: The differences in the level of expression and pattern of distribution of FGF2 suggests a potential role for FGF2 in the changes observed in prostatic growth in diabetic rats.

Animals↗

PubMed2000

Purification and characterization of a trypsin-like serine proteinase from rat brain slices that degrades laminin and type IV collagen and stimulates protease-activated receptor-2.

A trypsin-like serine proteinase was purified from the incubation medium of rat brain slices by gelatin zymography. The purification consisted of ammonium sulfate precipitation, benzamidine-Sepharose 6B affinity chromatography, and carboxymethyl-cellulose and gel filtration chromatographies. The gelatinolytic activity, identified at 22 kDa (P22) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions, was eluted as one active peak throughout the purification, and the final preparation gave a single protein peak on reverse-phase HPLC. Diisopropyl fluorophosphate, benzamidine, p-toluenesulfonyl-L-lysine chloromethyl ketone, and aprotinin completely inhibited the activity of P22, whereas phenanthroline, p-toluene-sulfonyl-L-phenylalanine chloromethyl ketone, and elastinal did not. P22 efficiently digested the extracellular matrix proteins laminin and type IV collagen. P22 produced an increase in intracellular Ca2+ concentration in A172 glioblastoma, which was desensitized through prior stimulation with protease-activated receptor-2 agonist peptide SLIGKV, indicating that P22 can stimulate protease-activated receptor-2. Rat brain penetration injury induced gelatinolytic activity in the lesioned area whose molecular size was consistent with that of P22. These results indicated that on incubation of rat brain slices, a trypsin-like serine proteinase was secreted into the medium that was capable of digesting extracellular matrix and stimulating protease-activated receptor-2. It is suggested that the gelatinolytic activity induced by brain injury might be that of P22.

Animals↗

PubMed2000

Distinct effects of CD30 and Fas signaling in cutaneous anaplastic lymphomas: a possible mechanism for disease progression.

Lymphomatoid papulosis is part of a spectrum of CD30+ cutaneous lymphoproliferative disorders characterized by spontaneous tumor regression. The mechanism(s) of regression is unknown. In a recent study, a selective increase in CD30 ligand expression in regressing lesions of lymphomatoid papulosis and cutaneous CD30+ anaplastic large cell lymphoma was shown, suggesting that activation of the CD30 signaling pathway may be responsible for tumor regression, whereas no difference in Fas/Fas ligand expression was found between regressing and nonregressing lesions. Therefore we tested the effects of CD30 and Fas activation on three CD30+ cutaneous lymphoma cell lines (Mac-1, Mac-2 A, JK) derived from nonregressing tumors of two patients who had progressed from lymphomatoid papulosis to systemic anaplastic large cell lymphoma. To evaluate the effects of CD30 signaling, the cell lines were incubated with a CD30 agonistic antibody, HeFi-1. Proliferative responses, mitogen-activated protein kinase, and nuclear factor kappa B activities were determined with and without CD30 activation. Mac-1 and Mac-2 A showed increased proliferative responses to incubation with CD30 activating antibody, HeFi-1. Inhibition of the mitogen-activated protein kinase activity caused growth inhibition of the Mac-1, Mac-2 A, and JK cell lines. Activation of the Fas pathway induced apoptosis in all three cell lines. Taken together, these findings suggest that resistance to CD30-mediated growth inhibition provides a possible mechanism for escape of cutaneous anaplastic large cell lymphoma from tumor regression. Mitogen-activated protein kinase inhibitors are potential therapeutic agents for the treatment of advanced cutaneous anaplastic large cell lymphoma. J Invest Dermatol 115:1034-1040, 2000

Cell Division↗

PubMed2000

The effect of hormone replacement therapy on CYP3A activity.

BACKGROUND: The effect of menopause and hormone replacement therapy on hepatic and intestinal wall CYP3A activity is poorly defined. This study was therefore designed to determine the effect of menopause and estrogen replacement therapy on hepatic and intestinal CYP3A activity with a specific CYP3A substrate, midazolam. METHODS: Twelve young women (27 +/- 5 years), 10 elderly women receiving estrogen replacement therapy (71 +/- 6 years), and 14 elderly women not receiving estrogen replacement therapy (71 +/- 5 years) received simultaneous intravenous (0.05 mg/kg over 30 minutes) and oral (3 to 4 mg of a stable isotope, 15N3-midazolam) doses of midazolam. Serum and urine samples were assayed for midazolam, 15N3-midazolam, and metabolites by use of gas chromatography-mass spectrometry. RESULTS: No significant (P > .05) differences were observed in systemic clearance and oral clearance between the three groups. Likewise, no differences were observed in oral, hepatic, or intestinal availability. A significant correlation was observed between oral and intestinal availability and not hepatic availability. CONCLUSION: Neither menopause nor menopause with estrogen replacement therapy altered intestinal or hepatic CYP3A activity relative to that in a control group of young women.

Administration, Oral↗

PubMed2000

Optimization of the size distribution and myocardial contrast effect of perfluorocarbon-filled albumin microbubbles by lyophilization under continuous negative pressure.

This study was undertaken to evaluate the effect of lyophilization under continuous negative pressure on perfluoropropane-filled albumin microbubble size distribution and myocardial contrast effect. Three different microbubble preparations were studied: (1) 1% albumin solution without a sugar (Optison), (2) 1% albumin and 5% dextrose (PESDA), and (3) 1% albumin and 5% fructose (PESFA). The 2 preparations containing sugar were also subjected to lyophilization under continuous negative pressure. Microbubble size distribution was measured with a Coulter Multisizer II (Beckman Coulter, Inc, Fullerton, Calif). The microbubbles were injected intravenously into a rat during intravital microscopy of the mesenteric microcirculation. Finally, the different albumin microbubbles were injected intravenously into 10 dogs, and myocardial contrast effect was assessed by videodensitometry. Results of the Coulter counter studies showed lyophilized PESFA to have a smaller size distribution with 99.9% + or - 0.1% of microbubbles <10 microm in diameter and 88.5% + or - 1.4% <4 microm in diameter (P <.05 compared with Optison or PESDA). On intravital microscopy, PESFA microbubbles behaved as intravascular tracers without microvascular plugging or coalescence. Finally, myocardial peak gray scale and area under the curve were significantly higher for PESFA than for PESDA or Optison, respectively. In conclusion, lyophilization of perfluoropropane-filled albumin microbubbles results in smaller microbubbles with a more uniform size distribution and brighter myocardial contrast. In addition, the substitution of fructose for dextrose improves size distribution and contrast effect. These findings have important implications regarding the use of novel imaging technologies that take advantage of microbubble destruction to image myocardial perfusion.

Albumins↗

PubMed2000

Effect of intranasal treatment with capsaicin on the recurrence of polyps after polypectomy and ethmoidectomy.

The aim of this study was to evaluate the influence of five intranasal applications of capsaicin, performed after endoscopic polypectomy associated with partial middle turbinectomy and anterior ethmoidectomy, on the recurrence of nasal polyps and the intensity of nasal obstruction and rhinorrhea. Fifty-one patients (19 females, 32 males, mean age 43 years) suffering from nasal polyposis for more than 1 year were included in this double blind, randomized, placebo-controlled study. During post-surgical controls, local anaesthesia and vasoconstriction of the middle meatus area were performed in all patients with a cotton pellet soaked with lidocain and adrenaline. In 29 patients, the same type of cotton pellet soaked with capsaicin (3 x 10(-6) mol. dissolved in 70% ethanol) was left into the middle meatus of both nostrils for 20 min. As a control group, 22 patients, matched for age and sex, were treated with the capsaicin vehicle alone (70% ethanol). All patients studied received the intranasal treatment once a week for 5 weeks. Subjective evaluations of nasal airway resistance (NAR) and rhinorrhea were recorded by means of a visual analogue scale. Clinical staging of the nasal polyposis (graded from stage 0 = absence of polyp to stage 3 = polyps occupying the entire nasal cavity) was evaluated by the same ENT specialist (ZW) using a 0 degrees endoscope. All parameters were recorded for each patient 1 week before surgery, then once a month for 9 months. Patients treated by endoscopic surgery followed by intranasal capsaicin application, reported a marked reduction in their NAR compared with the pretreatment evaluation (p<0.001). In contrast, patients treated with the vehicle alone did not have any significant improvement of their subjective NAR. Subjective rhinorrhea was not modified by either treatment. Patients treated with capsaicin showed a significant smaller staging of their nasal polyposis compared with the control group (p<0.001). These observations suggest that endoscopic surgery followed by intranasal capsaicin application reduces polyps and nasal obstruction recurrence and could be an alternative treatment to expensive corticosteroids in developing countries.

Administration, Intranasal↗

PubMed2000

Solid-phase microextraction coupled with high performance liquid chromatography: a complementary technique to solid-phase microextraction-gas chromatography for the analysis of pesticide residues in strawberries.

Solid-phase microextraction coupled with high performance liquid chromatography has been studied for the analysis of methiocarb, napropamide, fenoxycarb and bupirimate in strawberries. The strawberries were blended and centrifuged. Then, an aliquot of the resulting extracting solution was subjected to solid-phase microextraction (SPME) on a 60 microns polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibre for 45 min at room temperature. The extracted pesticides on the SPME fibre were desorbed into SPME/high performance liquid chromatography (HPLC) interface for HPLC analysis with diode-array detection (DAD). The method is organic solvent-free for the whole extraction process and is simple and easy to manipulate. The detection limits were shown to be at low microgram kg-1 level and the linear response covered the range from 0.05 to 2 mg kg-1 of pesticides in strawberries with a regression coefficient larger than 0.99. A good repeatability with RSDs between 2.92 and 9.25% was obtained, depending on compounds.

Chromatography, Gas↗

PubMed2000

Isolation of thirty-one new porcine microsatellites from a microsatellite enriched microdissected chromosome 8 library.

Chromosome 8 (SSC8) is an important one in the swine genome because it has been shown to harbor several economically important quantitative trait loci (QTL). The entire porcine chromosome 8 was microdissected and amplified by degenerate oligonucleotide primer (DOP) PCR. The PCR product was then enriched for (CA)n microsatellites by hybridization to a biotinylated CA repeat oligonucleotide and captured by streptavidin-coated magnetic beads. The captured DNA was cloned into a TA cloning vector. Screening with an isotopically labeled CA oligonucleotide probe resulted in the isolation of 31 informative and polymorphic microsatellite clones. Seventeen of those were mapped to chromosome 8, 12 to chromosome 15, 1 to chromosome 10 and 1 to chromosome X. The markers were all placed on the USDA-MARC porcine genetic linkage map.

Animals↗