Chicken PRDX3 is required for proliferation of chicken embryo fibroblast cells

1. This experiment investigated the influence of chicken PRDX3 on cell proliferation in chick embryo fibroblast cells using PRDX3 knockdown technology.2. A methyl thiazolyl tetrazolium (MTT) assay was performed to assess the effect of chPRDX3 knockdown on fibroblast proliferation. The antioxidant effect was investigated to determine if it directly mediated fibroblast cell proliferation.3. To determine the role of chPRDX3 on cell proliferation, an siRNA mediated knockdown was performed in chick fibroblast cells using an in vitro assay. The proliferation of fibroblast cells transfected with siPRDX3 #3 and siPRDX3 Mix was significantly decreased after 48 h (P < 0.01). In addition, the knockdown of chicken PRDX3 suppressed cell proliferation through an increase in oxidative stress.4. The results demonstrated that chPRDX3 is required for cell proliferation in chicken fibroblast cells. Such findings have important implications for the maintenance of chicken fibroblast cells.

Analysis of efficacy and safety of core-needle biopsy versus fine-needle aspiration cytology in patients with cervical lymphadenopathy and salivary gland tumour

In this study, we compared the diagnostic accuracy and safety of fine-needle aspiration cytology and core-needle biopsy in patients with cervical lymphadenopathy or salivary gland tumour, and provided a basis for selecting the appropriate diagnostic method in clinical situations. A total of 278 patients were included in this study. The sensitivities of fine-needle aspiration cytology and core-needle biopsy were 66.7% and 100%, respectively, and negative predictive values were 92.6% and 100%, respectively, for diagnosing malignancy. In diagnosing lymphoma, fine-needle aspiration cytology gave false-negative results in all patients. In diagnosing tuberculous lymphadenopathy, the sensitivities of fine-needle aspiration cytology and core-needle biopsy were 33.3% and 91.15%, respectively, and the negative predictive values were 90.0% and 95.1%, respectively. The sensitivities of fine-needle aspiration cytology and core-needle biopsy were 42.9% and 100% in diagnosing malignant salivary gland tumours, and the negative predictive values were 91% and 100%, respectively. The results of this study showed that core-needle biopsy was superior in diagnosing and distinguishing critical diseases such as malignant lymphadenopathy and tuberculosis in patients with cervical lymphadenopathy and salivary gland tumour.

Controlled delivery of a hydrophilic drug from a biodegradable microsphere system by supercritical anti-solvent precipitation technique

The purpose of this study was to prepare microspheres loaded with hydrophilic drug, bupivacaine HCl using poly(D,L-lactic-co-glycolic acid) (PLGA) and poly(L-lactic acid) (PLLA). Microspheres were prepared with varying the PLGA/PLLA ratio with two different levels of bupivacaine HCl (5 and 10%) using a supercritical anti-solvent (SAS) technique. Microspheres ranging from 4-10 microm in geometric mean diameter could be prepared, with high loading efficiency. Powder X-ray diffraction (PXRD) revealed that bupivacaine HCl retained its crystalline state within the polymer and was present as a dispersion within the polymer phase after SAS processing. The release of bupivacaine HCl from biodegradable polymer microspheres was rapid up to 4 h, thereafter bupivacaine HCl was continuously and slowly released for at least 7 days according to the PLGA/PLLA ratio and the molecular weight of PLLA.

The effect of beta-cyclodextrin complexation on the bioavailability and hepatotoxicity of clotrimazole

Clotrimazole, a poorly water-soluble antimycotic agent, is a promising therapeutic agent for various diseases including cancer and sickle cell anemia. The oral bioavailability and hepatic toxicity of clotrimazole were compared with its beta-cyclodextrin inclusion form which was prepared by the spray-drying method. The inclusion complex gave significantly higher initial plasma concentrations, Cmax and AUC than did clotrimazole alone, indicating that the drug from the inclusion compound could be more easily absorbed in rats. Furthermore, mice treated with the inclusion compound showed significantly higher GOT/GPT values compared to clotrimazole alone. The inclusion compound also induced hypertrophy of hepatic cells by fat accumulation and disappearance of hepatic sinusoids, indications of pathological changes of liver, suggesting that the inclusion compound could induce more severe tissue damage in the liver than clotrimazole alone. Thus, hepatotoxicity of clotrimazole seems to be correlated with the enhanced oral bioavailability by inclusion complexation. Our results suggest that, in the development of a novel oral product, appearance or enhancement of hepatic toxicity must be considered along with oral bioavailability.

Thyroid hemiagenesis: clinical significance in the patient with thyroid nodule

Thyroid hemiagenesis is a rare abnormality in which one thyroid lobe fails to develop. Most of the patients diagnosed have an associated thyroid disease. We report the case of a 32-year-old woman who presented with a left thyroid mass which had been gradually increasing in size over a period of two years. A thyroid scan revealed the absence of the right thyroid lobe and isthmus, and a hypoactive nodule was evident in the lower pole of the left lobe. Ultrasonography confirmed the right lobe and the isthmus agenesis. The operative findings confirmed hemiagenesis of the right lobe and nodular hyperplasia in the left lobe.

The purpose of this report is to present a patient with hemiagenesis of the thyroid gland who concomitantly had nodular hyperplasia; we also stress the importance of pre-operative differentiation between benign lesions and malignancy in order to aid critical decision making and to facilitate preservation of thyroid function if possible.

Clinical analysis of extranodal non-Hodgkin's lymphoma in the sinonasal tract

We investigated the clinical analysis of non-Hodgkin's lymphoma (NHL) of the sinonasal tract, including the survival rate and treatment outcome. Fifty patients who had previously received a diagnosis of extranodal NHL of the sinonasal cavity from May 1992 to April 2001 were included. We reviewed the patients' clinical characteristics and the survival rates, retrospectively. Of 50 patients, 49 were classified as having extranodal NK/T cell lymphoma and only one patient as having diffuse large B cell (DLBC) lymphoma according to the new WHO classification. Even though higher mortality rates were observed in patients receiving chemotherapy alone than in those receiving chemotherapy and radiation therapy in the advanced stage, the combination treatment of chemotherapy and radiation therapy failed to demonstrate a significantly higher survival rate.

Unique structural features of a BCL-2 family protein CED-9 and biophysical characterization of CED-9/EGL-1 interactions

The interactions between B-cell lymphoma 2 (BCL-2) family members are known to be mediated through the binding of the BH3 domain of a proapoptotic member to the BH3-binding groove of an antiapoptotic member. We determined the crystal structure of antiapoptotic CED-9, which reveals a unique C-terminal helix altering the common BH3-binding region. A coexpression system to produce CED-9 in complex with proapoptotic EGL-1 enabled us to show that the binding of EGL-1 to CED-9 is extremely stable, raising the melting temperature (T(M)) of CED-9 by 25 degrees C, and that the binding surface of CED-9 extends beyond the BH3-binding region and reaches the BH4 domain. Consistently, the T(M) and a 1H-15N correlation NMR spectrum of CED-9 in complex with EGL-1 are drastically different from those of CED-9 in complex with the EGL-1 BH3 peptide. The data suggest that the recognition between other BCL-2 family members may also involve much wider protein surfaces than is previously thought.

Effect of pentoxifylline on ischemic acute renal failure in rabbits

Previous studies have demonstrated that levels of tumor necrosis factor-alpha (TNF-alpha) or its mRNA expression are increased in acute renal failure of various types including ischemia/reperfusion injury. This study was undertaken to determine whether pentoxifylline (PTX), an inhibitor of TNF-alpha production, provides a protective effect against ischemic acute renal failure in rabbits. Renal ischemia was induced by clamping bilateral renal arteries for 60 min. Animals were pretreated with PTX (30 mg/kg, i.v.) 10 min before release of clamp. At 24 h of reperfusion of blood after ischemia, changes in renal function, renal blood flow, and the expression of TNF-alpha mRNA were evaluated. Ischemia/reperfusion caused a marked reduction in GFR, which was accompanied by an increase of serum creatinine levels. Such changes were significantly attenuated by PTX pretreatment. PTX ameliorated the impairment of renal tubular function, but it had no effect on the reduction of renal blood flow induced by ischemia/reperfusion. The protective effect of PTX on functional changes was supported by morphological studies. The impairment of glucose and phosphate reabsorption in postischemic kidneys was associated with a depression in the expression of Na+-glucose and Na+-Pi transporters. The expression of TNF-alpha mRNA was increased after reperfusion, which was inhibited by PTX pretreatment. The PTX pretreatment in vitro prevented the release of lactate dehydrogenase induced by an oxidant t-butylhydroperoxide in rabbit renal cortical slices, but it did not produce any effect on the oxidant-induced lipid peroxidation, suggesting that PTX protection is not resulted from its antioxidant action. These results suggest that PTX may exert a protective effect against ischemic acute renal failure by inhibiting the production of TNF-alpha in rabbits.

Nonselective left internal mammary artery angiography during right transradial coronary angiography: a simple, rapid, and safe technique

Internal mammary artery angiography is increasingly required, but the technique for left internal mammary artery (LIMA) angiography during right transradial coronary angiography is not well established. The authors investigated the feasibility and safety of a new, simple, and rapid nonselective technique. Following right transradial coronary angiography, LIMA angiography was performed using a 5 French (Fr) Judkins JL-3.5 catheter in 110 patients. The catheter, placed in the ascending aorta with its natural curve, was withdrawn slowly while being rotated clockwise to engage its tip in the proximal left subclavian artery. Contrast material was injected while sphygmomanometer cuff inflation was applied to the left upper arm. In the last 50 patients, the angiography was performed twice randomly with and without the cuff inflation. In 108 patients (98%), the catheter was successfully engaged in the subclavian artery in a mean of 11 +/- 8 seconds (range, 3-136) from the time when it was withdrawn from the ascending aorta, and nonselective LIMA angiography was successfully performed. The image quality of the angiograms was satisfactory in 103 (95%) of the 108 patients. In the last 50 patients, the image quality of the angiograms was determined satisfactory in 48 (96%) and 45 (90%) patients, with and without the cuff inflation, respectively. The difference was statistically not significant. There were no complications, including arterial dissection and thromboembolism. In conclusion, nonselective LIMA angiography can be readily and safely performed during right transradial coronary angiography using a 5 Fr Judkins JL-3.5 catheter.

Simplified retrograde systemic perfusion for removal of air from the aorta in an infant

Total circulatory arrest with full venous drainage can result in air entering the arterial system through several possible sites such as the aortic cannulation site or collateral vessels. Air present in the arterial system during total circulatory arrest imposes a special problem. We describe a simple technique of short-term retrograde systemic perfusion to remove air from the arterial system before restarting systemic arterial perfusion after total circulatory arrest.

Protective role of superoxide dismutase in rat eustachian tubal mucosa against acute otitis media induced by upper respiratory tract infection

Superoxide dismutase has been known to play a role as an anti-oxidative system against oxidative injury during acute inflammation. To investigate the role of superoxide dismutase in eustachian tubal mucosa during acute otitis media (AOM), an animal model was made. Sprague-Dawley rats were inoculated with Streptococcus pneumoniae through the nasal cavity following development of virus-induced upper respiratory infection. The animals were divided into three groups according to their tympanic cavity conditions following bacterial inoculation; inoculated animals with no resultant AOM (no-AOM), animals with resultant AOM (AOM) and animals with resolving otitis media (recovery). The changes of superoxide dismutase in each tubal mucosa were compared with that of the normal control using immunohistochemistry and immunoblotting methods. On Western blot, there were little changes of optical density and surface area in no-AOM (213.5 +/- 22.4, 13.2 +/- 0.8 mm2) and recovery group (219.3 +/- 18.7, 14.8 +/- 0.7 mm2) compared to the normal control (223.5 +/- 26.2, 16.7 +/- 0.4 mm2). However, a marked decrease was found in the AOM model (167.6 +/- 19.3, 6.5 +/- 0.9 mm2). These findings suggest that superoxide dismutase may play a role in protecting tubal mucosa from free radical injury during AOM.

Role of lipid peroxidation and poly(ADP-ribose) polymerase activation in oxidant-induced membrane transport dysfunction in opossum kidney cells

This study was undertaken to examine the role of lipid peroxidation and poly(ADP-ribose) polymerase (PARP) activation in H(2)O(2)-induced inhibition of Na(+)-dependent phosphate (Na(+)-Pi) uptake in opossum kidney (OK) cells. H(2)O(2) inhibited Na(+)-Pi uptake in a dose-dependent manner. H(2)O(2)-induced inhibition of Na(+)-Pi uptake was prevented by dithiothreitol and glutathione. A potent antioxidant, DPPD, had no effect on H(2)O(2) inhibition of Na(+)-Pi uptake, despite completely inhibiting lipid peroxidation induced by H(2)O(2). However, in primary cultured rabbit proximal tubular cells, the effect of H(2)O(2) on Na(+)-Pi uptake was significantly prevented by DPPD, suggesting a species difference in the role of lipid peroxidation in the inhibition of Na(+)-Pi uptake occurring with H(2)O(2). t-Butylhydroperoxide (tBHP) caused the inhibition of Na(+)-Pi uptake that was prevented by DPPD in OK cells and rabbit proximal tubular cells. The PARP inhibitor 3-aminobenzamide completely protected the inhibition of Na(+)-Pi uptake induced by H(2)O(2) but not by tBHP. H(2)O(2)-induced ATP depletion was prevented by 3-aminobenzamide but not by DPPD. tBHP-induced ATP depletion was prevented by DPPD, whereas it was not altered by 3-aminobenzamide. Effects of H(2)O(2) and tBHP on Na(+)-Pi uptake and ATP depletion were prevented by an iron chelator, deferoxamine, suggesting that the oxidants inhibit Na(+)-Pi uptake through an iron-dependent mechanism. The extent of DNA damage by tBHP was similar to that by H(2)O(2). These results indicate that the effect of H(2)O(2) on membrane transport function in OK cells is associated with PARP activation but not lipid peroxidation, whereas the effect of tBHP is associated with lipid peroxidation.

Effect of arachidonic acid metabolic inhibitors on hypoxia/reoxygenation-induced renal cell injury

The present study was undertaken to examine the role of arachidonic acid (AA) metabolites in hypoxia/reoxygenation (H/R)-induced renal cell injury in rabbit renal cortical slices using AA metabolic inhibitors. Inhibitors of cyclooxygenase (indomethacin and diclofenac sodium) and lipoxygenase pathways (nordihydroguaiaretic acid, caffeic acid, and eicosapentaenoic acid) reduced H/R-induced LDH release in a dose-dependent manner, whereas an inhibitor of cytochrome P-450 monooxygenase pathway ethoxyresorufin was not effective. AA increased LDH release in control slices, and the effect was not altered by indomethacin and nordihydroguaiaretic acid. The protective effect of indomethacin was not affected by addition of PGE2, a main product of cyclooxygenase pathway in the kidney. H2O2-induced LDH release was prevented by inhibitors of lipoxygenase but not by inhibitors of cyclooxygenase and cytochrome P-450 monooxygenase H/R-induced LDH release was not altered by iron chelators, phenanthroline and deferoxamine, and a potent antioxidant, N,N'-diphenyl-p-phenylenediamine, suggesting that the H/R-induced cell injury is not attributed to a generation of reactive oxygen species. Morphological studies showed that H/R-induced structural changes including cell necrosis were significantly prevented by indomethacin. These results suggest that inhibitors of cyclooxygenase and lipoxygenase pathways exert a direct protective effect against the H/R-induced cell injury in renal tubules. Whether these effects are mediated by alterations of AA metabolic pathways is not certain.

Mechanism of reduced GFR in rabbits with ischemic acute renal failure

A reduction in glomerular filtration rate (GFR) is a primary characteristic of ischemic acute renal failure. The present study was undertaken to examine the roles of angiotensin II, tubuloglomerular-feedback (TGF) mechanism, and tubular obstruction for the GFR reduction in the post-ischemic kidney. Renal ischemia was induced by occlusion of the bilateral renal arteries for 60 min, and renal function was examined at 2 and 24 h after the onset of reflow. After the end of 2-h reflow, the GFR was not significantly changed, but the urine flow increased significantly. On the other hand, at the end of 24-h reflow, the GFR and urine flow decreased markedly along with increased filtration fraction. The renal blood flow significantly decreased at 24 h, but not 2 h, after reflow, which was accompanied by increased total renal vascular resistance. Furosemide infusion (1 mg/min/kg) after 24 h of reflow prevented the reduction in GFR and filtration fraction without no changes in renal blood flow and total renal vascular resistance. Pretreatment of enalapril and losartan did not prevent the reduction in GFR, indicating that angiotensin II was not involved. In morphological examinations, tubular obstruction was seen in the proximal and distal tubules of kidneys both at 2 and 24 h after the onset of reflow. In two rabbits subjected to 48 h of reflow, the tubular obstruction was not observed, despite GFR remained depressed. These results suggest that the late reduction in GFR in postischemic kidneys is not mediated by angiotensin II, but is mediated, at least in part, by the TGF mechanism. The tubular obstruction may be not prerequisite for the GFR reduction in rabbits.

Topical oleo-hydrogel preparation of ketoprofen with enhanced skin permeability

In an attempt to improve the skin penetration of ketoprofen, various transdermal formulations were prepared, and their in vitro skin permeability and in vivo percutaneous absorption were evaluated. In vitro permeation studies were performed using a modified Franz cell diffusion system in which permeation parameters such as cumulative amount at 8 hr Q8hr, steady-state flux Jss, or lag time tL were determined. In the in vivo percutaneous absorption study using the hairless mouse, maximum concentration Cmax and area under the curve at 24 hr AUC24h were measured. The optimal transdermal formulation (oleo-hydrogel formulation) of ketoprofen showed a Q8hr value of 227.20 micrograms/cm2, a Jss value of 29.61 micrograms/cm2/hr, and a tL value of 0.46 hr. The Q8hr and Jss values were about 10-fold (p < .01) higher than those (Q8hr = 19.61 micrograms/cm2; Jss = 2.66 micrograms/cm2/hr) from the K-gel and about 3.5-fold (p < .01) than those (Q8hr = 60.00 micrograms/cm2; Jss = 7.99 micrograms/cm2/hr) of the K-plaster. In the in vivo percutaneous absorption, the Cmax (6.82 micrograms/ml) and AUC24h (55.74 micrograms.hr/ml) values of the optimal formulation were significantly (p < .01) higher than those of K-gel and K-plaster. The relative bioavailability of the oleo-hydrogel following transdermal administration in reference to oral administration was about 37%, and the Cmax value (4.73 micrograms/cm2) in the hypodermis following topical administration was much higher than those from the conventional products (Cmax of K-gel and K-plaster were 0.92 +/- 0.19 microgram/cm2 and 1.27 +/- 0.37 microgram/cm2, respectively). These data demonstrate that the oleo-hydrogel formulation of ketoprofen was more beneficial than conventional products (K-gel and K-plaster) in enhancing transdermal permeation and skin absorption of ketoprofen. Furthermore, there was a good correlation between in vitro permeation parameters and in vivo percutaneous absorption parameters.

Difference in H2O2 toxicity between intact renal tubules and cultured proximal tubular cells

The present study was undertaken to examine the response to H2O2 and t-butylhydroperoxide (t-BHP) in various in vitro model systems of renal proximal tubules: rabbit renal cortical slices, freshly isolated rabbit proximal tubules, rabbit primary cultured proximal tubular cells, and opossum kidney (OK) cells. t-BHP increased lactate dehydrogenase release and lipid peroxidation in a concentration-dependent manner over the concentration range of 0.2 to 3 mM in cortical slices, whereas H2O2 caused a similar concentration-dependent increase in both parameters at 5-100 mM. The sensitivity of isolated tubules to both peroxides was similar to that of cortical slices. In primary cultured cells and OK cells, however, the cytotoxicity of H2O2 was identical to that of t-BHP. The cytotoxicity of t-BHP was not different among all the systems examined. The specific activity of catalase in cortical slices was similar to that of isolated tubules, but it was much higher than that of primary cultured cells or opossum kidney cells. Glutathione (GSH) peroxidase activity was not different among all the systems examined. The expression of catalase mRNA in cortical slices and isolated tubules was higher than that in primary cultured cells, whereas those of superoxide dismutase, glutathione peroxidase, or beta-actin were not different among the systems. These results indicate that intact proximal tubules are more resistant to H2O2 than are cultured proximal tubular cells, and the resistance is due to a higher specific activity of catalase resulting from the increased expression of its mRNA.

The effect of galE gene inactivation on lipopolysaccharide profile of Helicobacter pylori

The galE gene product, UDP-galactose 4-epimerase, mediates the incorporation of galactose in extracellular polysaccharide materials such as the O-side chain of lipopolysaccharide (LPS). The O-side chain in H. pylori LPS has been shown to cross-react with Lewis x and/or y blood group antigens, suggesting its potential involvement in H. pylori-linked autoimmune disease. To study its role in H. pylori LPS biosynthesis, the galE gene was cloned, sequenced, and a galE-knockout H. pylori strain was constructed. The H. pylori galE gene encoded a protein of 344 amino acids with a molecular weight of 39K. The LPS profile from the galE-knockout H. pylori strain showed a lower molecular weight than that of the parental strain, indicating the involvement of the galE gene in LPS biosynthesis of H. pylori.

REP-PCR fragments as biomarkers for differentiating gastroduodenal disease-specific Helicobacter pylori strains

We previously identified four potential putative gastroduodenal disease fragments by using the interspersed repetitive extragenic palindromic DNA sequence based PCR (REP-PCR) technique. We investigated these fragments with regard to their disease specificity. The putative disease-specific REP-PCR fragments were cloned, mapped by restriction enzymes, cross-hybridized, and confirmed by Southern hybridization. The four fragments were also used as probes against REP-PCR amplicons from H. pylori isolates obtained from gastritis (N = 20), duodenal ulcer (N = 30), and gastric cancer patients (N = 30). Three of these fragments (1.4- and 0.76-kb for gastritis; 1.35 kb for duodenal ulcer) were amplified without any discrimination between any disease-specific H. pylori isolates. However, amplification following hybridization with the fourth 0.81-kb fragment was observed only from gastritis (60%) and duodenal ulcer (52%) but with none (0%) of gastric cancer patients. Nucleotide sequence analysis of the 0.81-kb fragment revealed that it was an open reading frame of the hypothetical protein HP0373 matched to the position of 380,966 to 383,068 nucleotides of the H. pylori complete genome sequence. Hence, the REP-PCR sequence was not a extragenic palindromic DNA sequence. The hypothetical protein was also present in all the tested isolates. The REP-PCR fingerprinting technique is useful to differentiate disease-specific H. pylori strains based on the interspersed repetitive extragenic palindromic DNA sequences; however, it may not be useful to identify disease-specific virulence determinant(s) without being confirmed by DNA sequence analysis and functional studies.

Adenylyl cyclase is involved in desensitization and recovery of ATP-stimulated Cl- secretion in MDCK cells

We investigated the process of and recovery from desensitization of the P2 receptor-mediated stimulation of Cl- secretion in Madin-Darby canine kidney (MDCK) cell monolayers by assaying the response of short-circuit current (Isc). When the cells were exposed to repeated 3-min challenges of ATP or UTP interspersed with 5-min washes, the response of Isc desensitized rapidly followed by spontaneous recovery. The pattern of inhibition by various channel blockers or enzyme inhibitors revealed that both the initial and recovered responses of Isc have the same ionic and signaling mechanisms. The desensitization and recovery processes were confined to the membrane exposed to the repeated challenges. When added during the desensitized phase, 8-bromoadenosine 3',5'-cyclic monophosphate enhanced the ATP-stimulated Isc response, whereas it did not during the initial or recovered phases. ATP-induced increases of intracellular adenosine 3',5'-cyclic monophosphate showed similar desensitization and recovery in parallel with the changes in the responses of Isc. The desensitization process was attenuated by pretreatment with cholera toxin or pertussis toxin. Taken together, our results suggest that the adenylyl cyclase system plays a role in the desensitization and recovery mechanism of the ATP-stimulated Cl- secretion in MDCK cells.

Role of purinergic receptors in chloride secretion in Caco-2 cells

Purinergic receptors play an important role in regulating Cl- secretion in epithelial cells. To explore further the role of these receptors in the intestine, we utilized the human intestinal epithelial cell line, Caco-2, grown on permeable membrane supports and assayed for Cl- secretion by measuring the short-circuit current (Isc). Stimulation of Isc by extracellular nucleotides could be detected by day 4 and increased by day 10 postseeding. The magnitude of stimulation of Isc at 10 microM in cells at day 10 was UTP > ATP > UDP > > 2-methylthioadenosine 5'-triphosphate (2-MeS-ATP) = ADP on the apical side and UTP = 2-MeS-ATP = ATP > ADP > > UDP on the basolateral side. Cross-desensitization studies suggested that two different receptors are expressed in the apical membrane, a P2U purinoceptor and a uridine nucleotide receptor. Two different receptors are also expressed in the basolateral membrane, a P2U receptor and another that reacts with both 2-MeS-ATP and ADP. This latter receptor has an unusual pharmacological profile, with a reactivity for 2-MeS-ATP > ADP but not for ATP. Responses to purinergic receptor agonists were inhibited by pretreatment with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester, thapsigargin, or quinine. Thus we suggest that an increase in intracellular Ca2+ and subsequent opening of Ca(2+)-activated K+ channel play a role in increasing driving force for Cl- to exit across the apical membrane. The role of the cystic fibrosis transmembrane conductance regulator as a Cl- exit pathway on the apical membrane was also established.

Failure to isolate Helicobacter pylori from stray cats indicates that H. pylori in cats may be an anthroponosis--an animal infection with a human pathogen

The recent isolation of Helicobacter pylori from cats obtained from a commercial supplier has potentially important public health implications. The present study investigated whether H. pylori infection was common in stray cats. Twenty-five cats were examined for the presence of H. pylori by histological examination, culture and two polymerase chain reaction (PCR) assays. Histologically, the gastric biopsy specimens from all cats showed large spiral organisms typical of H. felis and not H. pylori. Samples from 23 cats yielded bacterial growth and two had no growth. Colonies grossly similar to H. pylori were tested for catalase, oxidase, urease and Gram's stain reactions. None was H. pylori. All samples tested as positive by the Helicobacter 16S rRNA genus-specific PCR assay and only six cats and a mouse stomach infected with H. heilmannii gave positive results with the adhesin subunit A (hpaA)-specific PCR assay, which is consistent with either H. pylori or H. heilmannii. The helicobacters identified in these samples by PCR were not cultivable and hence were probably H. heilmannii. H. pylori infection is uncommon in stray cats and owning pet cats should not be a threat to public health in relation to H. pylori infection.

cGMP stimulates sodium and chloride currents in rat tracheal airway epithelia

To test the hypothesis that guanosine 3',5'-cyclic monophosphate (cGMP) regulates ion transport in airway epithelial cells, we measured short-circuit current (I(sc)) and (22)Na+ fluxes in primary cultured rat tracheal epithelial cells. In Cl- -containing Ringer solution, I(sc) was increased by approximately 17 microA/cm2 after application of 1 mM 8-bromoguanosine 3',5'-cyclic monophosphate (8-BrcGMP), whereas, in Cl- -free solutions, the Na+ -mediated component was approximately 5 microA/cm2, suggesting a cGMP stimulation of Cl-secretory current and a smaller Na+ absorptive current. Inward and net mucosal-to-serosal (22)Na+ flux was doubled in the presence of 2 mM 8-BrcGMP. To determine whether nucleotide-gated channels play a role in this transepithelial Na+ absorption, blockers of nucleotide-gated cation channels were used to inhibit I(sc). The cGMP-stimulated Na+-mediated I(sc) was blocked by as little as 500 nM dichlorobenzamil or 50 microM L-cis-diltiazem, which are known blockers for cyclic nucleotide-gated cation channels. These agents also blocked the basal (non-cGMP-stimulated) current when measured in the presence of 10 microM amiloride, which blocks current through 5-pS amiloride-sensitive Na+ channels. To document whether the distribution of nucleotide-gated nonselective cation channels was consistent with a role in airway epithelial transport, in situ hybridization was performed. In situ hybridization of mRNA encoding for nucleotide-gated cation channels was found in epithelial cell layers of rat trachea, bronchi, bronchioles, and alveolar cells but not in smooth muscle layers or tracheal cartilage. Reverse transcriptase-polymerase chain reaction, restriction enzyme analysis, and sequencing of the cDNA transcribed from mRNA of whole lung and tracheal epithelial cells indicate that a channel highly homologous to the retinal nucleotide-gated nonselective cation channel (CNG1) is present. Thus these data, along with evidence supporting the existence of signal transduction pathways elevating intracellular levels of cGMP, indicate that cGMP regulates transepithelial ion transport in lung epithelial tissues.

Agrin inhibits neurite outgrowth but promotes attachment of embryonic motor and sensory neurons

Agrin is a secreted glycoprotein with the ability to cluster cell surface molecules, including the nicotinic acetylcholine receptor (AchR) on muscle cells. Alternate splicing of agrin mRNA results in a family of agrin proteins which differ in their clustering potency. Neuronal-specific isoforms with the highest clustering activity play a role in clustering postsynaptic proteins at the neuromuscular junction. However, the function of agrin isoforms expressed in many nonneuronal tissues, and only weakly active in clustering assays, remains obscure. Monolayer cultures of Chinese hamster ovary (CHO) cells expressing a neuronal (agrin-19) or a nonneuronal (agrin-0) form of agrin were used to assay the effect of agrin on neurite outgrowth and cell attachment. These results were compared to outgrowth on control CHO cells expressing only drug resistance and on regions of CHO-agrin monolayers not expressing detectable levels of agrin. Neurite extension on confluent monolayers of agrin-0- or -19-expressing CHO cells was reduced substantially below that of controls. In one experiment neurite lengths were compared at 2 and 3 days after plating and suggested that neurite outgrowth may be stopped and not simply retarded. Attachment of sensory or motoneurons was nearly twofold higher to agrin monolayers than to control cells, showing that the inhibition is not a result of a nonpermissive environment. An agrin construct missing the C-terminal half, removing the major site of variability and clustering activity, was also tested. This construct did not reduce outgrowth, suggesting that the C-terminal half of the protein may be important in stopping growth as well as inducing clustering. These results expand the role of agrin in synaptogenesis as it may provide a stop signal at the myofiber surface and may anchor the presynaptic fibers to the eventual motor endplate .

The best gastric site for obtaining a positive rapid ureas test

BACKGROUND

Rapid ureas tests (RUTs) provide a simple, sensitive method of detecting Helicobacter pylori infection.

OBJECTIVES

Our aim, therefore, was to determine whether the yield of detecting H. pylori infection by RUT varied depending on the site of gastric biopsy.

MATERIALS AND METHODS

Gastric biopsies were obtained from 50 patients for RUT by use of hpfast (GI Supply, Camp Hill, PA). Biopsies were taken from the prepyloric greater curve antrum, from the gastric angle, and from the greater curve in mid-corpus. One biopsy specimen was placed in the RUT gel, and the biopsy from the adjacent mucosa was placed in formalin for subsequent histological evaluation by using the Genta stain. RUTs were examined and scored at intervals of 5, 10, 15, 30, and 45 minutes and after 1, 2, 4, and 24 hours.

RESULTS

Fifty patients were entered in the rest (150 RUTs), 32 having H. pylori infection. There were no false-positive RUTs (specificity, 100%). The gastric angle site was positive in 100%. The prepyloric site was positive in 87%, and the corpus site was positive in 84.4% (p < .052 for angle or prepyloric antrum versus corpus). The most common pattern was for all to be positive (74%). The median time to positivity was similar with angle and prepyloric sites (37.5 and 60 minutes, respectively, p = not significant) and shorter than the corpus biopsy (180 minutes); (p < .05 for angle or prepyloric antrum versus corpus).

CONCLUSION

The maximum probability for detecting H. pylori infection using a RUT is to obtain a biopsy from the gastric angle. To prevent missing a positive result when intestinal metaplasia is present, we recommend that (at a minimum) biopsies be taken from both the angle and the corpus.

Effect of renal ischaemia on organic compound transport in rabbit kidney proximal tubule

This study was carried out to determine the effect of renal ischaemia on transport systems for organic compounds in the rabbit kidney proximal tubule. Ischaemia for 30 or 60 min. induced glucosuria and phosphaturia, which was accompanied by polyuria and natriuresis. The Na(+)-dependent uptake of glucose, succinate and L-glutamate by brush-border membrane vesicles was not altered by 30 or 60 min. of ischaemia, while the H+/tetraethylammonium antiport was significantly inhibited after 30 min. of ischaemia. When the duration of ischaemia was extended to 120 min. the uptake of glucose and succinate by brush-border membrane vesicles was also significantly attenuated, but the L-glutamate uptake was not altered. The uptake of glucose, succinate and L-glutamate by basolateral membrane vesicles was not impaired even with 120 min. of ischaemia, suggesting that transport systems for organic compounds in the brush-border membrane are more sensitive to ischaemia than those in the basolateral membrane. Ouabain-sensitive oxygen consumption in renal cortical slices was not depressed by 60 min. of ischaemia. When kidneys were reperfused for 60 min. following 60 min. of ischaemia, the Na(+)-glucose and Na(+)-succinate cotransport and the H+/tetraethylammonium antiport were not different from the control, but the recovery of alkaline phosphatase was significantly reduced. When kidneys were subjected to ischaemia for 60 min., a loss of brush-border microvilli and plasma membrane was observed after 5 or 60 min. of reflow in the proximal convoluted tubule. After 3 hr of reflow, focal necrosis appeared although the microvilli were partially regenerated.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of cisplatin on renal function in rabbits: mechanism of reduced glucose reabsorption

This study was performed to determine the effect of cisplatin (cis-diamminedichloroplatinum II) on renal function in rabbits. Injection of a single i.p. dose of 4 mg/kg cisplatin caused an increase in fractional excretion of Na+ and K+ and a decrease in urine osmolality (Uosm), free-water reabsorption, (TcH2O), and urine to plasma creatinine ratio (U/Pcr). Urine flow was decreased following cisplatin treatment, which was accompanied by marked reduction in GFR. Cisplatin induced glucosuria, phosphaturia, and aminoaciduria. These results suggest that cisplatin results in impaired proximal tubular reabsorptive function and the renal concentrating defect. Cisplatin treatment impaired the accumulation of PAH and TEA and ouabain-sensitive oxygen consumption in renal cortical slices. Na(+)-K(+)-ATPase activity in renal cortical microsomes and basolateral membrane vesicles was significantly depressed in cisplatin-treated animals. Cisplatin treatment did not affect the Na(+)-dependent uptake of glucose and L-glutamate by brush-border membrane vesicles (BBMV), but caused a significant decrease in Na(+)-dependent succinate and H(+)-dependent TEA uptake. Morphological observations showed that cisplatin caused a focal loss of the microvillus brush border. These results suggest that (1) cisplatin induces oliguric acute renal failure in rabbits and (2) glucosuria induced by cisplatin was not due to a direct impairment of glucose transporter in brush-border membranes but due to an inhibition of Na(+)-pump activity and a decrease in area for active glucose reabsorption in the proximal tubule.

Revascularization of the ischemic colon transplant using the internal mammary vessels

We describe a successful reconstruction of the esophagus with the isoperistaltic right colon and terminal ileum, which had very poor continuity of the marginal artery. The stomach and the left colon were not available because of corrosive injury and intraabdominal adhesions. The blood supply of the ischemic transplant was augmented by anastomosis of the internal mammary vessels to the iliocolic vessels.

Effect of t-butylhydroperoxide on p-aminohippurat uptake in rabbit renal cortical slices

OBJECTIVES

Oxygen free radical (superoxide radical, hydrogen peroxide, and hydroxyl radicals) have been considered to be responsible for the pathogenesis of ischemia reperfusion injury and toxic chemical injury in a variety of organs including myocardium, brain, intestine and kidneys. In in vitro models using a suspension of rat proximal tubule segments, t-butylhydroperoxide(t-BHP), a potent oxidant, induces the severity of tubular dysfunction as reflected by decreases in tubular respiration which is associated with a progressive increase in lipid peroxidation. The precise mechanism of t-BHP-induced cell injury remains to be determine. The study was carried out to determine the effect of oxygen free radicals on organic anion transport in renal proximal tubule.

METHODS

By renal cortical slices, we studied accumulation of organic ions, PAH efflux oxygen consumption, lactate dehydrogenase (LDH), lipid peroxidation. The data are expressed as the mean +/- SE and evaluated for significance using Student's t-test. A probability level of 0.05 was used to establish significance.

RESULTS

Effect of t-butylhydroperioxide(t-BHP), a potent oxidant, on organic anion p-amminohippurate(PAH) uptake was studied in rabbit renal cortical slices. t-BHP inhibited irreversibly PAH and organic cation tetraethylammonium(TEA) uptake in a dose dependent manner with IC50 of approximately 1.0 and 0.85 mM, respectively. The efflux rate constant pf PAH was not altered by the presence of 1 mM t-BHP, indicating that the inhibitory effect of t-BHP on the steady-state accumulation of PAH is due primary to the reduction in the influx of PAH across the basolateral membrane. The kinetic analysis showed that 1mM t-BHP caused a significant reduction in the maximum rate of PAH influx(Vmax) from 1.54 +/- 0.74 to 0.72 +/- 0.54 umol/g/10 min without an effect on Km, indicating that t-BHP depressed PAH influx across the basolateral membrane by reducing the number or turnover rate of active carrier for PAH transport, but not by altering substrate affinity of the carrier. Ouabain-sensitive and -insensitive oxygen consumption was not different between the control and t-BHP-treated slices. t-BHP caused an increase in LDH release and lipid peroxidation in a dose-dependent manner, which were highly correlated with changes in PAH uptake.

CONCLUSION

These results suggest that t-BHP inhibition of PAH uptake is attributed to renal tubular cell damage and lipid peroxidation plays an important role in the inhibitory effect of t-BHP on PAH transport in rabbit proximl tubules.

Solitary rectal ulcer syndrome

We report three cases of solitary rectal ulcer syndrome (SRUS). The diagnosis was established according to histopathologic criteria. But, the initial clinical diagnosis was carcinoma, non-specific ulcer and localized proctitis respectively. SRUS is considered as one of functional disorder in pelvic floor which might go underdiagnosed due to unfamiliar concept in Korea. So we should consider SRUS to be one of the differential diagnosis in cases of complaining anorectal symptoms.

Maternal determinants of birthweight in normal pregnancy

Partial and multiple regression analysis was performed to find out the correlation between birthweight and maternal anthropometric variables. Pearson regression analysis revealed significant dependence of birthweight on gestation of pregnancy, maternal weight, symphysis-sternal distance and height, but not on armspan and skin thickness. However, the only maternal variable bearing significant influence on birthweight in partial regression analysis was bodyweight. The effects of maternal determinants on birthweight, though some of them were statistically significant, were clinically unimportant.

Middle cerebral artery Doppler flow velocity waveforms

Doppler flow velocity-time waveforms of the middle cerebral arteries at their origin from the internal carotid arteries were obtained serially on 14 patients to determine the alterations of these waveforms with gestational age. Satisfactory recordings were obtained from all patients. The middle cerebral artery waveforms demonstrated a typically biphasic pattern with continuing forward flow in diastole. The peak systolic to end-diastolic ratio (A/B ratio) showed a progressive and significant decline from 6.89 +/- 1.48 at around 25 weeks to 4.23 +/- 0.67 at term. Elevation of diastolic velocities and diminished A/B ratio in the middle cerebral arteries were noted in four fetuses, in whom severe antepartum compromise was diagnosed. The ratio also appeared to decrease with worsening of fetal condition. Because the fetus compensates for hypoxia by increasing blood flow to the brain, Doppler middle cerebral artery waveforms may permit evaluation of fetal compromise and hypoxia.

Characteristic pattern of Doppler umbilical arterial velocity waveform in conjoint twins

Doppler blood flow studies in a pair of conjoint twins at 18 weeks gestation revealed a characteristic 'double layer' spectral velocity waveform from the umbilical arteries. This is the result of signals originating from 2 separate arterial supplies adjacent to each other in a single umbilical cord. Such a characteristic feature provides an additional sonographic sign in the diagnosis of conjoint twins.

Non-resolution of pelvic sonographic abnormality after chemotherapy for persistent trophoblastic disease--a word of caution

A case of persistent trophoblastic disease (PTD) is presented in whom pelvic sonography demonstrated persistent uterine abnormality and dilated adnexal vessels after cessation of chemotherapy. Hysterectomy was performed on account of subsequent uterine bleeding. A viable tumour was not demonstrated in the hysterectomy specimen. In the absence of haemorrhagic complications persistent sonographic abnormality should not necessarily indicate hysterectomy, especially when hCG levels are normal.

Intrauterine growth standards for Hong Kong Chinese

Intrauterine growth standards for Hong Kong Chinese were derived from birth-weight data between 28 and 42 weeks' gestation in 15,815 livebirths delivered in 1982 to 1984 at 2 maternity teaching hospitals in Hong Kong. Normal distribution of birth-weights was noted in each of the gestational weeks studied. The mean birth-weight was 3,237g at 40 weeks which was similar to the mean weights reported in other populations for this gestation. The trend of the median weight curve was also similar to that in other Caucasian and Asian reports. The growth pattern for males and females were similar and males were on the whole heavier than females throughout the gestational period studied. At 40 weeks, the 10th percentile weight also showed wide variations between reports, which would have important bearing on the studying of intrauterine growth retardation. When the mean weight at term as derived from the present study was compared to a previous report on birth-weight data in 1970-1972 in the same hospital, a significant increase in birth-weight was observed over the 12-year period. The importance of having up-to-date intrauterine weight standards for a specific population is discussed.

Aetiological factors in the genesis of pregnancy hydronephrosis

In order to identify possible aetiological factors in the genesis of physiological hydronephrosis in pregnancy, the degree of pelvic-calyceal dilatation in 90 asymptomatic pregnant women was correlated with levels of plasma oestradiol, progesterone, 24-hour urinary oestriol, the site of the placenta, birthweight of the fetus, and pelvic inlet measurements. A grading system based on maximum calyceal diameter was used; 90% of the patients were found to have at least mild dilatation on the right side. No correlation was demonstrated between the degree of hydronephrosis and the levels of oestradiol, progesterone and 24-hour urinary oestriol excretion. The birth-weight of the fetus and its relationship with the pelvic inlet measurements also did not correlate with the occurrence of hydronephrotic changes in the kidneys. The only significant positive finding was a higher incidence of moderate and severe hydronephrosis occurring in patients with a right-sided placenta than compared with the left (x2 = 4.77; p less than 0.05), although the sensitivity and specificity in predicting hydronephrosis from a right-sided placenta is low (53% and 66% respectively). Our results support the hypothesis of a mechanical aetiology in the genesis of pregnancy hydronephrosis, where vascular compression on the ureters may be an important contributory factor. Our study has also shown that urinary tract infection and reduction of creatinine clearance were not more common in patients with moderate or severe pelvic-calyceal dilatation.

Estimation of fetal weight in utero from symphysis-fundal height and abdominal girth measurements

The ability to estimate fetal weight accurately from symphysis-fundal height (SFH) and abdominal girth (AG) measurements was evaluated. Multivariate regression analysis was performed on measurements made on 208 primigravidas within 48 hours of delivery. A better correlation with birth-weight was obtained with the SFH than with the AG. The equation BW = -1.515 + 0.092 (SFH) + 0.016 (AG) yielded a coefficient of multiple correlation of 0.7259. Using this equation, the mean percentage prediction errors were 5.7% +/- 4.2(SD) in fetuses between 2,500 and 3,500 g (n = 156), 9.4% +/- 5.25(SD) in those larger than 3,500 g (n = 33), and 19.1% +/- 8.2(SD) in those smaller than 2,500 g (n = 19). All the generated equations similarly underestimated the fetal weight in the larger babies and overestimated in the smaller babies. Inclusion of quadratic and logarithmic functions as well as skin-fold thickness measurements into the equations did not decrease the error or alter the distribution of errors. It was concluded that although fetal weight estimation may be reasonably accurate between 2,500 g and 3,500 g, the error is too great for the method to be clinically useful in the smaller and larger babies. Moreover, a theoretical basis for a high sensitivity in the detection of small for dates fetuses from these parameters would be difficult to establish.

Zinc deficiency is not a cause for abortion, congenital abnormality and small-for-gestational age infant in Chinese women

Zinc concentration in serum and hair was measured in a cross-sectional study of 437 Chinese women of whom 310 were normal controls studied at various stages of pregnancy and up to 12 months after delivery. The rest had spontaneous abortions, fetuses with a birthweight below the 10th centile for gestation or congenital abnormalities. Zinc concentration fell throughout normal pregnancy, the fall being greater in serum than in hair. There was no correlation between serum and hair levels. The infant birthweight had a positive correlation with serum level but a negative correlation with hair level. Abortion, low birthweight and congenital abnormality were not associated with low concentrations of zinc in plasma or hair.

Intrauterine death from ergotamine overdosage

Fetal death in a primigravid patient who had taken an overdose of ergotamine tartrate is presented. Non-stress cardiotocography performed shortly after admission was technically unsatisfactory for interpretation but revealed the presence of very frequent uterine contractions. The cause of fetal death in this patient is discussed. Overdosage of ergotamine must be considered a serious threat to the well-being of the fetus in utero.

Puerperal ovarian vein thrombophlebitis

A 16 year old Chinese female with puerperal ovarian vein thrombophlebitis following uneventful vaginal delivery is reported. This infrequent, but potentially fatal, complication in the febrile postpartum patient may present as a surgical emergency. Non-invasive diagnostic procedures and conservative treatment with heparinization and antibiotics have been suggested. However, early exploratory laparotomy for ovarian vein or caval ligation may be life-saving if the diagnosis is in doubt or the response to conservative treatment is unsuccessful.

Advanced pregnancy in the rudimentary horn of a bicornuate uterus

Ultrasound was useful for the diagnosis of advanced pregnancy in the non-communicating rudimentary horn of a bicornuate uterus. The role of ultrasonography in early diagnosis of this condition in order to improve fetal salvage was discussed.

Evaluation of a prenatal screening procedure for beta-thalassaemia carriers in a Chinese population based on the mean corpuscular volume (MCV)

Haemoglobin A2 (HbA2) levels were determined on 25 beta-thalassaemia carriers by the microcolumn method and were found to range from 4.5-7.2 per cent (mean 5.2 +/- 0.82 S.D.). The haemoglobin level (Hb), mean corpuscular volume (MCV), plasma ferritin and HbA2 levels were measured on a further 299 consecutive Chinese pregnant women at a gestation of less than 24 weeks. 18 patients (6 per cent) had HbA2 level greater than 4.5 per cent and were diagnosed to be beta-thalassaemic carriers. It was observed that all these patients had a MCV below 75 fl. If this level is selected in a screening procedure based on measurement of MCV alone all beta-thalassaemia carriers could be detected and 11 per cent of the population screened would require HbA2 estimation. At a lower cut-off level of 70 fl, 8 per cent of the population screened would require HbA2 measurement (a decrease of 27 per cent) but the detection rate will be lowered considerably (83 per cent). The high false positive rate at all cut-off levels of MCV was largely due to the prevalence of iron deficiency anaemia in the population. Estimation of plasma ferritin level in patients with low MCV will reduce this false positive rate, but there will be a considerable delay in diagnosis in patients with concomitant iron deficiency and beta-thalassaemia. The presence of iron deficiency in beta-thalassaemia carriers did not reduce their HbA2 level below the diagnostic range in this study.(ABSTRACT TRUNCATED AT 250 WORDS)

Fetal loss from umbilical cord abnormalities--a difficult case for prevention

The summaries of 12 pregnancies in which fetal distress and death were thought to be the result of umbilical cord abnormalities are presented. These included six cases of stricture and torsion of the cord, one case of umbilical vein aneurysm, one case of perivascular haemorrhage near the fetal end of the cord, one case of umbilical vein thrombosis, two cases of true knot of the cord and one case of very short cord. The perinatal mortality was 75% in the whole group (9 out of 12 fetuses), there being eight stillbirths and one neonatal death. Of the 12 fetuses, only three were small for dates at delivery. Nine patients volunteered the history of a decrease in fetal movements, and non-stress cardiotocography (NST) was abnormal in eight patients. It was noted, however, that fetal death tended to occur rapidly after an abnormal test. Observations in our series indicated that antepartum fetal deaths due to umbilical cord abnormalities are still difficult to prevent, as it is often impossible to detect fetal distress in time for appropriate intervention. Prompt action to deliver the baby after an abnormal NST appears to be a necessary step to prevent antepartum deaths due to such causes.