Stress failure plays a major role in the development of high-altitude pulmonary oedema in rats

Hypoxia and exertion are considered as the two main factors in the development of high-altitude pulmonary oedema (HAPE), however its pathophysiology remains unclear. Therefore, we established a model in which 32 Sprague-Dawley rats were randomly assigned to normoxic rest, hypoxic rest, normoxic exercise and hypoxic exercise. An altitude of 4,700 m was simulated using hypobaric hypoxia, while exercise consisted 48 h walk with 15-20 min breaks every 4 h. Arterial blood gas, bronchoalveolar lavage (BAL), lung wet-to-dry weight (W/D) ratio and histological measurements were conducted on each animal. In rats exercising in hypoxia, BAL protein and lung W/D ratio were significantly increased but no changes in BAL leukotriene B(4) and immunoglobulin M were observed. In the same group, lung histology showed typical haemorrhagic lung oedema and disruption of both alveolar epithelium and capillary endothelium while hypoxia or exertion alone only induced slight endothelium and epithelium swelling/disruption. Our study established a direct link between histological and physiological evidence of HAPE-like symptoms and we demonstrated that hypoxia and exertion can synergistically induce HAPE-like symptoms in Sprague-Dawley rats without inducing lung inflammation. We therefore propose that alveolar epithelium and capillary endothelium stress failure play a major role in the development of HAPE.

Potential therapy of Fc-antigen combination-encoding DNA vaccination in mouse allergic airway inflammation

Vaccination with allergen-encoding DNA has been proposed as having potential for allergen-specific immunotherapy. In this study, we examine the therapeutic effect of allergen-encoding DNA vaccination directly to dendritic cells (DCs) on allergen-induced allergic airway inflammation in a mouse model and explore potential mechanism. Ovalbumin (OVA)-sensitized and challenged mice were immunized with DNA vaccine and received bronchoalveolar lavage (BAL) 1 day after the last challenge, to measure BAL levels of interleukin (IL)-4, IL-5, interferon (IFN)-gamma and differential cell count. Pulmonary DCs and Spleen DCs were purified and sorted according to the expression of CD(11c) (+)CD(80) (+) and CD(11c) (+)CD(86) (+) co-stimulatory molecules. Our data demonstrated that DNA vaccine therapy with OVA-Fc-pcDNA(3.1) significantly prevented OVA-increased levels of IL-4, IL-5 and the percentage of eosinophils and OVA-decreased level of IFN-gamma. OVA-Fc-pcDNA(3.1)-treated mice had less severity of airway inflammation, and lower expression of CD(11c) (+)CD(80) (+) and CD(11c) (+)CD(86) (+) on pulmonary DCs, as compared with animals with OVA-pcDNA(3.1,) pcDNA(3.1) and OVA respectively. DNA vaccine encoding both Fc and OVA was shown to be more effective than DNA vaccine encoding OVA alone. Our data indicate that Fc-antigen combination-encoding DNA vaccination has better preventive effects on antigen-induced airway inflammation by regulating DCs, and may be a new alternative therapy for asthma.

A phase II dose finding study of darbepoetin alpha and filgrastim for the management of anaemia and neutropenia in chronic hepatitis C treatment

Dose reductions of pegylated interferon alpha and ribavirin may be avoided by using growth factors. This phase II clinical trial assesses the dose, efficacy and safety of darbepoetin alpha and filgrastim for treatment of anaemia and neutropenia associated with combination therapy for hepatitis C virus (HCV). Chronic hepatitis C patients (n = 101) received pegylated interferon alpha-2b (1.5 mug/kg once weekly) and ribavirin (800-1400 mg once daily). Patients with anaemia [haemoglobin (Hb) </= 10.5 g/dL] received darbepoetin alpha (3 mug/kg once every 2 weeks); the dose was titrated to achieve a Hb level of 12.0 g/dL. Patients with neutropenia [absolute neutrophil count (ANC) </= 0.75 x 10(9)/L] received filgrastim with the dose titrated from 150 mug QW to 300 mug thrice weekly to maintain ANC >/= 0.75 x 10(9)/L and <10 x 10(9)/L. During antiviral therapy, 52% of patients required darbepoetin alpha, filgrastim or both. Hb at the time of darbepoetin alpha initiation was 10.2 +/- 0.4 g/dL. After 81 days of darbepoetin alpha, Hb increased by 1.9 +/- 1.0 g/dL to 12.1 +/- 1.1 g/dL (P < 0.0001). Filgrastim resulted in a significant increase in ANC [0.75 +/- 0.16 x 109/L to 8.28 +/- 5.67 x 10(9)/L (P < 0.0001)]. In treatment-naïve patients, 48% achieved sustained virological response (SVR), whereas 27% of patients previously treated with a course of pegylated interferon alpha achieved SVR. Low viral load, nongenotype 1 and treatment with growth factors were independently associated with SVR. Mild and severe anaemia were associated with quality of life impairments. Darbepoetin alpha resulted in an improvement in the Vitality domain of Short Form-36. No significant adverse events were related to growth factors. During anti-HCV therapy, filgrastim improved neutropenia and darbepoetin alpha improved both anaemia and quality of life. Future randomized clinical trials are needed to establish the impact of growth factors in improving sustained virological response.

Possible role of hydrogen sulfide on the preservation of donor rat hearts

OBJECTIVE

The aim of this study was to observe the preservative effect of hydrogen sulfide (H2S) on donor rat hearts.

MATERIALS AND METHODS

The hearts of 24 Sprague-Dawley rats were perfused on a Langendorff perfusion column for 30 minutes. We calculated and recorded the left ventricular-developed pressure (LVDP), and positive and negative derivatives of left ventricular systolic pressure (LVSP; +dP/dt and -dP/dt). Hearts were then arrested and stored for 6 hours at 4 degrees C: group 1, Krebs-Henseleit (KH) solution; group 2, KH solution with 1 micromol/L NaHS; group 3, KH solution with 1 micromol/L NaHS and 10 micromol/L glibenclamide; group 4, St. Thomas II solution. Hearts were transferred back to the Langendorff column. After stabilizing for 30 minutes, LV performance was assessed as before. The donor hearts were kept for pathological study including myocardial water ratio, ATP content, and myocyte apoptosis index.

RESULTS

The recovery rates of +dp/dtmax, -dp/dtmax, and LVDP of groups 2 and 4 were much better than those of groups 1 and 3. The hearts contracted immediately after reperfusion in group 4. Ventricular fibrillation was seen before contraction in the other 3 groups, with the longest duration in group. No significant difference in myocardial water ratio was found. The ATP content was the highest in group 2. Apoptosis was observed in the 4 groups with the lowest apoptosis index in group 2.

CONCLUSIONS

H2S has a protective effect on rat donor hearts at the concentration of 1 micromol/L. The protective effect is better than that of St. Thomas II solution. The protective effect of H2S can be blocked by glibenclamide.

Role of enteral nutrition supplemented with ebselen and EHEC in pancreatitis-associated multiple organ dysfunction in rats

OBJECTIVES

To investigate potential effects of ebselen and ethylhydroxyethyl cellulose (EHEC) on the acute phase responses and the severity of multiple organ dysfunction associated with acute pancreatitis.

METHODS

Acute pancreatitis was induced by intraductal infusion of 5% sodium taurodeoxycholate. The increase of total protein content in the BALF was used as an indication for acute lung injury, plasma amylase for pancreatic damage, plasma bilirubin for acute liver dysfunction, and plasma creatinine for acute kidney dysfunction. Levels of interleukin (IL)-6, macrophage inflammatory protein (MIP)-2 in the BALF were determined by ELISA.

RESULTS

There was a dose-related tendency for ebselen or EHEC alone to prevent organ dysfunction and reduce elevated plasma levels of IL-6 and ICAM-1 expression on circulating leukocytes 12 h after AP induction. The combination of ebselen and EHEC significantly prevented pancreatitis-induced multiple organ injury, IL-6 production and ICAM-1 expression in rats and exhibited better effects than either monocompound alone.

CONCLUSION

The combination of ebselen and EHEC may be a new potential for treatment of acute severe pancreatitis.

Humanin delays apoptosis in K562 cells by downregulation of P38 MAP kinase

Humanin (HN) is a newly identified neuroprotective peptide. In this study, we investigated its antiapoptotic effect and the potential mechanisms in K562 cells. Upon serum deprivation, expression of HN in K562 cells decreased and its intracellular distribution changed from cytoplasm to cell membrane. In HN stably transfected K562 cells, apoptosis was delayed compared with control vector transfected cells as measured by flow cytometry. Furthermore, analysis of different mitogen-activated protein (MAP) kinases activity revealed that extracellular signal-regulated kinase (ERK) pathway was inhibited while p38 signaling was activated following serum deprivation in K562 cells. And in HN transfected K562 cells, ERK downregulation was not affected, but p38 activation was suppressed, which may responsible for the delayed apoptosis in these cells. Activation of the ERK signaling pathway by phorbol myristate 13-acetate (PMA) and sorbitol protected K562 cells from serum deprivation induced apoptosis. Additionally, overexpression of HN reduced megakaryocytic differentiation of K562 cells. The present data outline the role of ERK and p38 MAP kinases in serum deprivation induced apoptosis in K562 cells and figure out p38 signaling pathway as molecular target for HN delaying apoptosis in K562 cells.

Partial agonist/antagonist properties of androstenedione and 4-androsten-3beta,17beta-diol

Androgens play important endocrine roles in development and physiology. Here, we characterize activities of two "Andro" prohormones, androstenedione (A-dione) and 4-androsten-3beta,17beta-diol (A-diol) in MDA-MB-453 (MDA) and LNCaP cells. A-dione and A-diol, like cyproterone acetate, were partial agonists of transfected mouse mammary tumor virus (MMTV) and endogenous prostate-specific antigen (PSA) promoters. Different from bicalutamide but similar to CPA, both are inducers of LNCaP cell proliferation with only mild suppression of 5alpha-dihydrotestosterone (DHT)-enhanced cell growth. Like bicalutamide and cyproterone acetate, A-dione and A-diol significantly antagonized DHT/R1881-induced PSA expression by up to 30% in LNCaP cells. Meanwhile, in MDA cells, EC(50)s for the MMTV promoter were between 10 and 100nM. Co-factor studies showed GRIP1 as most active for endogenous androgen receptor (AR), increasing MMTV transcription by up to five-fold, without substantially altering EC(50)s of DHT, A-dione or A-diol. Consistent with their transcriptional activities, A-dione and A-diol bound full-length endogenous AR from MDA or LNCaP cells with affinities of 30-70nM, although binding to expressed ligand-binding domain (LBD) was >20-fold weaker. In contrast, DHT, R1881, and bicalutamide bound similarly to LBD or aporeceptor. Together, these data suggest that A-dione and A-diol are ligands for AR with partial agonist/antagonist activities in cell-based transcription assays. Binding affinities for both are most accurately assessed by AR aporeceptor complex. In addition to being testosterone precursors in vivo, either may impart its own transcriptional regulation of AR.

A novel gene, GliH1, with homology to the Gli zinc finger domain not required for mouse development

The Sonic hedgehog (Shh)-Gli signaling pathway regulates development of many organs, including teeth. We cloned a novel gene encoding a transcription factor that contains a zinc finger domain with highest homology to the Gli family of proteins (61-64% amino acid sequence identity) from incisor pulp. Consistent with this sequence conservation, gel mobility shift assays demonstrated that this new Gli homologous protein, GliH1, could bind previously characterized Gli DNA binding sites. Furthermore, transfection assays in dental pulp cells showed that whereas Gli1 induces a nearly 50-fold increase in activity of a luciferase reporter containing Gli DNA binding sites, coexpression of Gli1 with Gli3 and/or GliH1 results in inhibition of the Gli1-stimulated luciferase activity. In situ hybridization analysis of mouse embryos demonstrated that GliH1 expression is initiated later than the three Gli genes and has a more restricted expression pattern. GliH1 is first detected diffusely in the limb buds at 10.0 days post coitus and later is expressed in the branchial arches, craniofacial interface, ventral part of the tail, whisker follicles and hair, intervertebral discs, teeth, eyes and kidney. LacZ was inserted into the GliH1 allele in embryonic stem cells to produce mice lacking GliH1 function. While this produced indicator mice for GliH1-expression, analysis of mutant mice revealed no discernible phenotype or required function for GliH1. A search of the Celera Genomics and associated databases identified possible gene sequences encoding a zinc finger domain with approximately 90% homology to that of GliH1, indicating there is a family of GliH genes and raising the possibility of overlapping functions during development.

[Significance of lung perfusion scanning with technetium labeled macroaggregated albumin and pulmonary function assay for diagnosis of early hepatopulmonary syndrome]

OBJECTIVE

To evaluate the values of pulmonary function assay and dynamic pulmonary perfusion imaging with technetium labeled macroaggregated albumin ((99m)TcMAA) in the early diagnosis of hepatopulmonary syndrome (HPS).

METHODS

The pulmonary function assay and (99m)TcMAA scans were performed in 28 patients with HPS, 30 cirrhotic patients (CP) without HPS, and 21 healthy controls (HC).

RESULTS

In the patients with HPS, PaO(2), SaO(2) and diffusion capacity for carbon monoxide of lungs (DLco) was significantly lower than that in CP (P<0.01) and HC (P<0.01), and alveolar-arterial gradient [P((A-a))O(2)] was significantly increased (P<0.001). Results from (99m)TcMAA scans showed that the radionuclides were distributed over the spleen, kidney, liver and brain, and the ratios of arterivenous shunt were significantly higher than that in CP (P<0.001) and NC (P<0.001). In cirrhotic patients, DLco significantly decreased (P<0.05), P((A-a))O(2) and shunt ratios increased (P<0.01 and 0.001).

CONCLUSIONS

Pulmonary function assay and dynamic pulmonary perfusion imaging with (99m)TcMAA are sensitive methods for diagnosis of the early HPS.

Investigation of thrombomodulin and plasminogen activator inhibitor type-I in pregnancy induced hypertension and its clinical significance

OBJECTIVE

To measure the circulating levels of thrombomodulin (TM) and plasminogen activator inhibitor type-I (PAI-I) in women with pregnancy induced hypertension (PIH).

METHODS

Blood samples were drawn from 97 pregnant women in their third trimester, grouped as 25 mild PIH, 26 moderate PIH, 22 severe PIH and 24 normotensive healthy pregnant women for determining levels of TM by ELISA, PAI-I by colorimetric assay methods, and creatinine (Cr) in serum by biochemical method.

RESULTS

Circulating levels of TM, PAI-I and TM/Cr ratio increased with increasing severity of PIH. There were no significant differences between mild and normotensive pregnant women. The parameters were significantly changed in the moderate and severe PIH groups.

CONCLUSION

TM and PAI-I may serve as meaningful clinical markers for the assessment of the endothelial damage in PIH, which is very important in evaluating and following the development of PIH.

Some applications of a chiral fluorometric reagent, (S)-TBMB carboxylic acid

Molecular design and applications of a fluorometric chiral agent, (S)-TBMB carboxylic acid, are briefly reviewed. The agent, possessing an asymmetric 1,3-benzodioxole skeleton, was designed as a novel class of chiral agent that functions also as a benzoate chromophore for exciton chirality CD methods. The utility of this agent has been demonstrated in an application to determine enantiomeric amino acids, acyl-sn-glycerols, glycosyl-sn-glycerols, and other chiral alcohols and amines.

Branched nanowire based guanine rich oligonucleotides

Self-assembly and aggregation of guanine rich sequences can provide useful insights into DNA nanotechnology and telomeric structure and function. In this paper, we designed a guanine rich sequence d(GGCGTTTTGCGG). We found that it can form stable structure in appropriate condition and it exhibits an anomalous CD spectra. This structures can be imaged in ambient environment with a Nanoscope III AFM (Digital Instruments). We found it forms branch structure and long multistrand DNA nanowire after incubation at 37 degrees C for 6-12 hours in 25 mM TE (pH=8.0) + 5 mM Mg2+ + 50 mM K+. The ability to self-assemble into branches and long wires not only clearly demonstrate its potential as scaffold structures for nanotechnology, but also give aids to understand telomeric structure further. We have proposed a model to explain how these structures formed.

DNA-protein crosslinks induced by nickel compounds in isolated rat lymphocytes: role of reactive oxygen species and specific amino acids

Isolated rat lymphocytes in salts-glucose medium (pH 7.2) were incubated with nickel chloride, nickel acetate, nickel sulfate, and a soluble form of nickel subsulfide (0-2 mM) at 37 degrees C for 2 h. The soluble form of nickel subsulfide induced a significant increase in DNA-protein crosslinks (DPXLs) (111%) beginning at 0.5 mM and a maximum increase of 700% from that of the control value was reached at a 2 mM concentration, whereas nickel sulfate produced only a 65% increase of such crosslinks at the 2 mM concentration only. No significant reduction in viability of rat lymphocytes (as measured by trypan blue exclusion) due to these nickel compounds was observed at any concentration used. Time-course studies of DPXLs and cellular viability due to 2 mM nickel subsulfide indicate that DPXL formation may not be due in part to cellular necrosis. Coincubation of nickel subsulfide (2 mM) with l-histidine (16 mM), l-cysteine (4 or 8 mM), or l-aspartic acid (24 mM) significantly reduced the DPXLs induced by 2 mM nickel subsulfide. But Mg(2+) even at 24 mM failed to antagonize nickel subsulfide-induced increase in DPXLs. High concentrations of these amino acids significantly decreased the accumulation of Ni(2+) from nickel subsulfide in lymphocytes, suggesting that such reduction of cellular uptake of Ni(2+) by these amino acids is partly responsible for the potent protective effects of these amino acids against such genotoxicity of nickel subsulfide. In vitro exposure of lymphocytes to nickel subsulfide (0-2 mM) increased the formation of reactive oxygen species (ROS) in a concentration-dependent manner. Furthermore, coincubation of 2 mM nickel subsulfide with catalase, dimethylthiourea, mannitol, or vitamin C at 37 degrees C for 2 h resulted in a significant decrease of nickel subsulfide-induced formation of DPXLs, suggesting that nickel subsulfide-induced DPXLs formation in isolated rat lymphocytes is caused by the formation of ROS. The amino acid treatment also abrogated Ni(3)S(2)-induced generation of ROS. Deferoxamine (a highly specific iron chelator) treatment prevented nickel subsulfide-induced DNA-protein crosslink formation, suggesting that Ni(2+)-induced DPXL formation in rat lymphocytes is caused by the induction of Fenton/Haber-Weiss reaction, generating hydroxyl radicals. The potent protective effects of these specific amino acids against nickel subsulfide-induced DPXL formation in isolated rat lymphocytes may be due in part to impaired cellular uptake of Ni(2+), inhibition of the binding of Ni(2+) to deproteinized DNA, and a reduction in reactive oxygen species.

[Experimental study for lung fluid transport by epithelial cells and aquaporins]

OBJECTIVE

To explore the effects of aquaporins (AQP) 1, 4 on water transport between airspace and pulmonary capillary and high pressure pulmonary edema. The other purpose was to study the active alveolar fluid transport as well as alveolar fluid clearance (AFC) in different pH of airspace.

METHODS

The effects of AQP1, 4 on water transport between airspace and pulmonary capillary and high pressure pulmonary edema were studied by surface fluorescence methods and gravimetric method respectively, AFC and AFC in airspace with different pH were measured by isotope method.

RESULTS

AQP1 knockout inhibited water transport through pulmonary capillary and also reduced high pressure pulmonary edema. Salbutamol increased AFC, but it was reduced when propranolol was used together. AFC was improved by terbutaline, isoproterenol, salmeterol when pH > 2.5 in airspace, but the effect was reduced after pH < 2.5 in airspace. Sodium channel inhibitor, Benzamil, could also inhibit AFC.

CONCLUSIONS

AQP1 knockout significantly reduced water transport through alveolar capillary, and also reduced high pulmonary edema slightly. beta adrenergic stimulant improved AFC in mechanically ventilated rats. Intact airspace is very important for the function of AFC, however, the effect of AFC was impaired after lung injury induced by pH < 2.5 in airspace.

[A study on the deficiency of anticoagulant proteins in Chinese patients with deep venous thrombosis]

OBJECTIVE

To investigate the incidence of anticoagulant proteins deficiency in Chinese patients with venous thrombosis.

METHODS

Eighty-seven patients with otherwise unexplained venous thrombophilia were studied. Both the antigen and antivitity of PC, PS, and antithrombin III (ATIII) were determined using commercial kits (Stago, or IL) activated PC, sensitivity ratio (APC-SR) by Coatest chromogenix, and factor V gene mutation by polymerase chain reaction with restriction fragments long polymorphism (PCR-RFLP).

RESULTS

Of all the patients twenty-five were found to be abnormal. These consisted of 3 ATIII deficiencies, 5 PC deficiencies, 10 PS deficiencies, 2 resistance of activated protein C (APC-R), 1 combined ATIII and PC deficiency, 1 combined ATIII and PS deficiency, 1 combined PC and PS deficiency, 1 combined APC-R and PC deficiency and 1 combined APC-R and PS deficiency. The overall prevalence of ATIII, PC and PS deficiencies was 26.4%. The patients with anticoagulant proteins deficiency had earlier onset (35.2 +/- 9.7 vs 42.1 +/- 10.9; P < 0.01) and more recurrent thrombosis (P < 0.05), as well as more pulmonary embolism (44.0% vs 16.1%; P < 0.01) than those of without anticoagulant protein deficiency.

CONCLUSION

The overall prevalence of ATIII, PC, and PS deficiency in Chinese venous thrombosis patients was higher than that of Western patients. It suggests that the etiology of thrombophilia may be different between Chinese and Western.

[The meridian flowing and ancient Chinese philosophy]

The theories of Yin - Yang and Five - Evolutive phase were extensively applied after pre - Qin and both Han dynasties. In the Song - Ming dynasties, the background of New Confucianism, the achievements of art of Yi(Changes) advocated by the "School of Configuration - Arithmatic" were applied, in which the method of "Adopting of Jia" was almost entirely derived from the above school, mixing the theories of heavenly stems - earthly branches, Five - evolutive phases and Yin - Yang as a whole. An ancient system of Chronological treatment was thus established creatively by integrating clinical experience together. The system is a tight system of grafting medicine and philosophy formed on the basis of successfully utilizing the philosophical framework, thinking proposed by ancient physicians with keen observation and deep ponderation. The system is, by then, an advanced one, which is also an inevitable one.

Atomic force microscopy analysis of intermediates in cobalt hexammine-induced DNA condensation

The packaging pathway of cobalt hexammine-induced DNA condensation on the surface of mica was examined by varying the concentration of Co(NH3)6(3+) in a dilute DNA solution and visualizing the condensates by atomic force microscopy (AFM). Images reveal that cobalt hexammine-induced DNA condensation on mica involves well-defined structures. At 30 microM Co(NH3)6(3+), prolate ellipsoid condensates composed of relatively shorter rods with linkages between them are formed. At 80 microM Co(NH3)6(3+), the condensed features include toroids with average diameter of approximately 240 nm as well as U-shaped and rod-like condensates with nodular appearances. The results imply that the condensates, whether toroids, U-shaped or rod-like structures have similar intermediate state which includes relatively shorter rod-like segments. The average size of the condensed toroids after incubated at room temperature for 5 h (approximately 240 nm) is much larger than that incubated for 0.5 h (approximately 100 nm). The results indicate that the condensation of DNA by Co(NH3)6(3+) is a kinetic-controlled process.

Effects of protein-deficient nutrition during rat pregnancy and development on developmental hindlimb crossing due to methylmercury intoxication

Pregnant rats were fed either a control (20% protein) or low (3.5%) protein diet during gestation and lactation. The pups were separated from their mothers on postnatal day 21, and were given the same diet as their corresponding mothers. The groups of pups from each diet group were treated on either postnatal day 21 or postnatal day 60 with 7.5 mg methylmercury chloride (MeHgCl) per kg b.w. once daily by gavage for 10 consecutive days, and the development of ataxia (hind-limb crossing) was monitored. The offspring from mothers on the protein-deficient diet were found to be more sensitive to MeHg-induced ataxia than those on the protein-sufficient diet. The former accumulated more mercury in different brain regions than the latter. The rates of protein synthesis in different brain regions of the offspring fed the protein-deficient diet were significantly reduced compared with the rates in those fed the protein-sufficient diet. However, MeHg treatment did not significantly modify the rates of such protein synthesis further in protein-deficient rats. Thus, a significantly much higher inhibition of the intrinsic rates of protein synthesis in different brain regions due to severe protein deficiency, as observed in this study, may be partly responsible for the increased susceptibility of developing rats fed a protein-deficient diet to MeHg-induced ataxia, or hindlimb crossing, although other factor(s) might also be involved.

Role of aquaporins in alveolar fluid clearance in neonatal and adult lung, and in oedema formation following acute lung injury: studies in transgenic aquaporin null mice

Aquaporin (AQP) water channels provide a major pathway for osmotically driven water movement across epithelial and microvascular barriers in the lung. We used mice deficient in each of the three principal lung aquaporins, AQP1, AQP4 and AQP5, to test the hypothesis that aquaporins are important in neonatal lung fluid balance, adult lung fluid clearance and formation of lung oedema after acute lung injury. Wet-to-dry weight ratios (W/D) in lungs from wild-type mice decreased from 7.9 to 5.7 over the first hour after spontaneous delivery. AQP deletion did not significantly affect W/D at 45 min after birth. Alveolar fluid clearance was measured in living ventilated mice in which 0.5 ml saline containing radiolabelled albumin was instilled into the airspaces. Fluid clearance was 17.4 % in 15 min and inhibited >90 % by amiloride, but clearance was not affected by AQP deletion. W/D was measured in established models of acute lung injury - acid aspiration and thiourea administration. Two hours after intratracheal administration of HCl, W/D increased from 3.7 to 7.5 but was not affected by AQP deletion. Three hours after intraperitoneal infusion of thiourea, W/D increased to 5.5 and marked pleural effusions appeared, but there were no differences in wild-type and AQP knockout mice. Hyperoxic subacute lung injury was induced by 95 % oxygen. Neither mean survival (143 h) nor W/D at 65 h (5.1) were significantly affected by AQP deletion. Despite their role in osmotically driven lung water transport, aquaporins are not required for the physiological clearance of lung water in the neonatal or adult lung, or for the accumulation of extravascular lung water in the injured lung.

A slice-by-slice blurring model and kernel evaluation using the Klein-Nishina formula for 3D scatter compensation in parallel and converging beam SPECT

Converging collimation increases the geometric efficiency for imaging small organs, such as the heart, but also increases the difficulty of correcting for the physical effects of attenuation, geometric response and scatter in SPECT. In this paper, 3D first-order Compton scatter in non-uniform scattering media is modelled by using an efficient slice by-slice incremental blurring technique in both parallel and converging beam SPECT. The scatter projections are generated by first forming an effective scatter source image (ESSI), then forward-projecting the ESSI. The Compton scatter cross section described by the Klein-Nishina formula is used to obtain spatial scatter response functions (SSRFs) of scattering slices which are parallel to the detector surface. Two SSRFs of neighbouring scattering slices are used to compute two small orthogonal 1D blurring kernels used for the incremental blurring from the slice which is further from the detector surface to the slice which is closer to the detector surface. First-order Compton scatter point response functions (SPRFs) obtained using the proposed model agree well with those of Monte Carlo (MC) simulations for both parallel and fan beam SPECT. Image reconstruction in fan beam SPECT MC simulation studies shows increased left ventricle myocardium-to-chamber contrast (LV contrast) and slightly improved image resolution when performing scatter compensation using the proposed model. Physical torso phantom fan beam SPECT experiments show increased myocardial uniformity and image resolution as well as increased LV contrast. The proposed method efficiently models the 3D first-order Compton scatter effect in parallel and converging beam SPECT.

Mouse Gli1 mutants are viable but have defects in SHH signaling in combination with a Gli2 mutation

The secreted factor Sonic hedgehog (SHH) is both required for and sufficient to induce multiple developmental processes, including ventralization of the CNS, branching morphogenesis of the lungs and anteroposterior patterning of the limbs. Based on analogy to the Drosophila Hh pathway, the multiple GLI transcription factors in vertebrates are likely to both transduce SHH signaling and repress Shh transcription. In order to discriminate between overlapping versus unique requirements for the three Gli genes in mice, we have produced a Gli1 mutant and analyzed the phenotypes of Gli1/Gli2 and Gli1/3 double mutants. Gli3(xt) mutants have polydactyly and dorsal CNS defects associated with ectopic Shh expression, indicating GLI3 plays a role in repressing Shh. In contrast, Gli2 mutants have five digits, but lack a floorplate, indicating that it is required to transduce SHH signaling in some tissues. Remarkably, mice homozygous for a Gli1(zfd)mutation that deletes the exons encoding the DNA-binding domain are viable and appear normal. Transgenic mice expressing a GLI1 protein lacking the zinc fingers can not induce SHH targets in the dorsal brain, indicating that the Gli1(zfd)allele contains a hypomorphic or null mutation. Interestingly, Gli1(zfd/zfd);Gli2(zfd/+), but not Gli1(zfd/zfd);Gli3(zfd/+) double mutants have a severe phenotype; most Gli1(zfd/zfd);Gli2(zfd/+) mice die soon after birth and all have multiple defects including a variable loss of ventral spinal cord cells and smaller lungs that are similar to, but less extreme than, Gli2(zfd/zfd) mutants. Gli1/Gli2 double homozygous mutants have more extreme CNS and lung defects than Gli1(zfd/zfd);Gli2(zfd/+) mutants, however, in contrast to Shh mutants, ventrolateral neurons develop in the CNS and the limbs have 5 digits with an extra postaxial nubbin. These studies demonstrate that the zinc-finger DNA-binding domain of GLI1 protein is not required for SHH signaling in mouse. Furthermore, Gli1 and Gli2, but not Gli1 and Gli3, have extensive overlapping functions that are likely downstream of SHH signaling.

Fold-back tetraplex DNA species in DNase I-resistant DNA isolated from HeLa cells

A DNase I-resistant DNA species has been isolated and purified from HeLa cells by gel electrophoresis. Our studies indicate that the DNase I-resistant DNA species was about 40-60 bp fragment sizes responding to double-strand DNA marker and has higher guanine content. The image of AFM showed that this species has been assumed to be tetraplex structure according to its apparent width and height. Its CD, UV spectrum also exhibited characteristics similar to some tetraplex structure, which was different from the standard duplex DNA. 32P-labeled probes (TTAGGG)4 and 5'-TGGGGAGGGTGGGGAGGGTGGGGAAGG-3' could be hybridized to purified DNase I-resistant species. All results suggest that the DNase I-resistant DNA species have at least two components, which adopt an intrastrand fold-back DNA tetraplex. Their sequences were similar to human telomere and human c-myc locus (NHE), respectively.

Genetic analysis of a La homolog in Drosophila melanogaster

People afflicted with certain rheumatological auto-immune diseases produce autoantibodies directed against a select group of proteins such as the La auto-antigen. Biochemical studies have revealed La to be a promiscuous RNA-binding protein that appears to play a role in a variety of intracellular activities such as processing and/or transport of RNA polymerase III precursor transcripts and translational regulation from internal ribosome entry sites (IRES). We have previously identified an RNA-binding protein that is a Drosophila melanogaster homolog of La (D-La) and shown that early transcript accumulation throughout the embryo is later refined to be most prevalent in the visceral mesoderm, gut, gonads and salivary glands. Here we report the first in vivo genetic characterization of a La homolog in a multicellular eukaryote. Lethality was observed in homozygous larvae harboring a small chromosomal deletion that removed the D-La gene, which was rescued by an inducible D-La cDNA transgene. This implies that D-La confers essential functions for larval development. In addition, loss of D-La function gives rise to defects in embryonic midgut morphogenesis; one of the midgut defects correlates with loss of Ultrabithorax ( Ubx ) expression along the second midgut constriction. Finally, genetic interactions between chromosomal deficiencies that remove D-La and certain Ubx alleles were demonstrated in adults. Our results support the hypothesis that D-La provides essential functions for proper Drosophila development and imply that the conserved La family of proteins may perform critical developmental functions in higher eukaryotes.

Surgical treatment of portal hypertension: 45 year experience

OBJECTIVE

To review the experience in surgery for 912 patients with portal hypertension.

METHODS

The 912 patients were divided into three groups: before 1978 (group A), 1978 - 1989 (group B), and 1990 - 1998 (group C). The results were reviewed of portosystemic shunt (PSS), disconnection and disconnection plus PSS for emergency and elective operation at different periods.

RESULTS

In the 912 patients of groups A, B, C, the number of PSS, disconnection, and PSS plus disconnection was 345, 13, 0; 84, 209, 0; 63, 204, 63, respectively. The number of emergency operation was 45, 13 and 4 in each group. The operative mortality of shunt in the groups A, B, C was 7.82%, 7.14% and 0, respectively; that of disconnection in the groups A, B, C 15.38%, 6.28% and 4.94%; and that of PSS plus disconnection in group C 3.51%. Encephalopathy occurred in 14.37% of the PSS group, in 5.68% of the disconnection group, and in 5.77% of the disconnection plus PSS group. Rebleeding occurred in 10.78% of the PSS group, in 18.95% of the disconnection group, and in 7.69% of the disconnection plus PSS group.

CONCLUSIONS

Operative indications for the cirrhotic patients with portal hypertension depend on their liver function. For those patients with poor liver function, surgery is considered when their liver function is improved. We suggest prophylactic operation is valuable. Other indices from barium meal, color ultrasound, and endoscopy are also considered. The number of emergency operation has been decreasing. Since the 1980s, disconnection operation has been adopted increasingly. In our hospital, the number of patients receiving disconnection has been increasing from the early 1980s and the operation has almost replaced shunt operation in the 1990s. Disconnection combined with splenorenal shunt can lower the portal pressure and maintain the portal flow. Disconnection combined with splenorenal shunt seems to be a better procedure of choice.

Overexpression of M68/DcR3 in human gastrointestinal tract tumors independent of gene amplification and its location in a four-gene cluster

Fas-mediated apoptosis is an important regulator of cell survival, and abnormalities in this system have been shown to result in a number of human pathological conditions. A secreted member of the tumor necrosis factor receptor superfamily, DcR3, was recently reported to be amplified in human lung and colon cancers as a negative regulator of Fas-mediated apoptosis. We identified this gene, which we call M68. M68 genomic DNA, mRNA, and protein levels were examined in a series of human gastrointestinal tract tumors. Using M68 immunohistochemistry and a scoring system similar to that used for HER-2/neu, we found that M68 protein was overexpressed in 30 of 68 (44%) human adenocarcinomas of the esophagus, stomach, colon, and rectum. Tumors examined by Northern blot revealed M68 mRNA highly elevated in a similar fraction of primary tumors from the same gastrointestinal tract regions, as well as in the colon adenocarcinoma cell lines SW480 and SW1116. Further, we found M68 protein to be overexpressed in a substantial number of tumors in which gene amplification could not be detected by fluorescence in situ hybridization or quantitative genomic PCR, suggesting that overexpression of M68 may precede amplification in tumors. Finally, we find that M68 lies within a four-gene cluster that includes a novel helicase-like gene (NHL) related to RAD3/ERCC2, a plasma membrane Ras-related GTPase and a member of the stathmin family, amplification or overexpression of which may also contribute to cell growth and tumor progression.

Identification of urotensin II as the endogenous ligand for the orphan G-protein-coupled receptor GPR14

Urotensin II (UII) is a neuropeptide with potent cardiovascular effects. Its sequence is strongly conserved among different species and has structural similarity to somatostatin. No receptor for UII has been molecularly identified from any species so far. GPR14 was cloned as an orphan G protein-coupled receptor with similarity to members of the somatostatin/opioid receptor family. We have now demonstrated that GPR14 is a high affinity receptor for UII and designate it UII-R1a. HEK293 cells and COS-7 cells transfected with rat GPR14 showed strong, dose-dependent calcium mobilization in response to fish, frog, and human UII. Radioligand binding analysis showed high affinity binding of UII to membrane preparations isolated from HEK293 cells stably expressing rat GPR14. In situ hybridization analysis showed that GPR14 was expressed in motor neurons of the spinal cord, smooth muscle cells of the bladder, and muscle cells of the heart. The identification of the first receptor for UII will allow better understanding of the physiological and pharmacological roles of UII.

[Study on thrombomodulin and plasminogen activator inhibitor type-1 in patients of pregnancy induced hypertension]

OBJECTIVE

To study the circulating levels of Thrombomodulin (TM) and Plasminogen activator inhibitor type-1 (PAI-1) in women with pregnancy induced hypertension (PIH) and normal pregnant women.

METHODS

Blood samples were withdrawn from 73 pregnant women, In which 25 mild PIH, 26 moderate PIH, 22 severe PIH were divided into study group, and 24 normotensive healthy pregnant women in their third trimester were control group. The determination of TM was measured by ELISA and PAI-1 by Colorimetric Assay methods.

RESULTS

Circulation levels of TM and PAI-1 were increased with increasing severity of the PIH. There were no significant differences between groups of mild PIH and normal pregnancy (TM 45.69 +/- 15.15 micrograms/L and 40.14 +/- 15.82 micrograms/L, PAI-1 22.06 +/- 12.13 kU/L and 18.40 +/- 9.78 kU/L respectively). The parameters significantly increased in moderate (TM 52.76 +/- 13.91 micrograms/L, PAI-1 25.77 +/- 9.45 kU/L) and severe PIH (TM 64.84 +/- 15.16 micrograms/L, PAI-1 30.79 +/- 11.64 kU/L) groups.

CONCLUSIONS

These results demonstrate that the endothelial cell damage and its functional disturbance play a very important role in the etiology of PIH. TM and PAI-1 may serve as clinical markers for the assessment of endothelial damage in PIH.

[Factor V Leiden and PTG20210A gene mutation in patients with venous thrombosis and healthy blood donors]

OBJECTIVE

To evaluate the incidence of factor V Leiden and prothrombin gene G20210A mutation in patients with venous thrombosis and healthy volunteers.

METHODS

Factor V Leiden and prothrombin gene G20210A mutation were analysed in 97 cases of venous thrombosis and 100 healthy volunteers with the methods of one-step PCR-RFLP.

RESULTS

PCR products for the factor V gene (175 bp) and for the prothrombin gene (118 bp) were identified to 157 bp and 98 bp fragments by electrophoresis after Taq I treatment. No factor V Leiden and prothrombin gene G20210A mutation were found in either group.

CONCLUSION

The low incidence of factor V Leiden and prothrombin gene G20210A mutation suggest that they are not the major genetic risk factors for thrombophilia in the Chinese.

[Human motion analysis system based on common video-camera]

A new human motion analysis system based on common video-camera is introduced in this paper. The image processing technique is used to recognize and track anatomic landmarks, which makes data processing more quickly and accurately. The system is cost-effective and can be easily operated because the common video-cameras instead of special instruments are used. Furthermore, the system can also be used for detection and analysis of other low-speed moving objects.

[Clinical analysis of 12 cases with venous thromboembolism during pregnancy and puerperium]

OBJECTIVE

To study the incidence, cause and clinical manifestation of venous thromboembolism during pregnancy and puerperium, and its diagnosis and treatment.

METHODS

12 cases of venous thromboembolism admitted in our hospital from 1984-1997 were analysed retrospectively. The plasma protein C, protein S and antithrombin III activities were measured in 4 of the cases and activated protein C resistance (APC-R) were assayed by activated partial thrombinplastin time (APIT) in the presence and absence of APC (APC-APIT) and FV Leiden gene mutation were analysed by PCR restriction fragment length polymorphisms (RFLP) methods as well.

RESULTS

Four cases occurred before delivery and 8 postpartum. Two cases complicated by pulmonary thromboembolism, and of them 1 died. APC-R(+), reduced activity of antithrombin-III and protein S each were found in 3 separate cases. No FV Leiden gene mutation was found in the 4 cases.

CONCLUSIONS

The formation of venous thromboembolism during pregnancy and puerperium is highly associated with the deficiency of anticoagulant proteins. Anticoagulation is recommended in the high risk women of thromboembolism.

The diagnostic value of total respiratory impedance by impulse oscillometry in chronic obstructive lung disease

OBJECTIVE

To investigate the diagnostic significance of total respiratory impedance for chronic obstructive lung disease.

METHODS

The impedance of respiratory system was measured by impulse oscillometry method and compared with parameter values of routine pulmonary function in 57 patients with chronic obstructive pulmonary disease (COPD).

RESULTS

It significantly increased in viscous resistance ranging from 5 Hz and 35 Hz and resonant frequency in COPD group than that in healthy group. Reactance from 5 Hz and 35 Hz in COPD group was marked lower than that in healthy group. There were marked frequency dependence of viscous resistance and reactance in COPD patients. Resonant frequency was markedly and negatively correlated with parameters of pulmonary ventilation indices; X5 was positively correlated with parameters of pulmonary ventilation indices. But no statistical correlation was showed between R20 and parameters of pulmonary ventilation indices. Correlation was found between resonance frequency and FEV1, resonance frequency and Vmax. The correlation coefficient values were -0.671 and -0.666 respectively. The sensitivity of resonant frequency, R5 and X5 for diagnosing COPD were 94.74%, 59.65% and 54.38%, respectively. The specificity of them were 86.66%, 96.66% and 90%, respectively.

CONCLUSIONS

Resonant frequency was the most sensitive index in the parameters measured by IOS for diagnosing COPD. Since impedance measurement was a non-invasive method and only passive co-operation of the patient was needed. This technique could therefore be applied in COPD patients with acute attack for dynamic examination.

Role of oxidative stress in nickel chloride-induced cell injury in rat renal cortical slices

Nickel chloride (NiCl2) induced lactate dehydrogenase (LDH) release and lipid peroxidation (LPO) in rat renal cortical slices in vitro in a concentration- (0-2 mM) and time- (0-4 hr) dependent manner, with initial significant LDH release occurring as early as 1 hr, whereas significant increase in LPO started 3 hr after exposure, suggesting that LPO results from renal cell injury. Both NiCl2-induced LDH release and LPO were prevented significantly by glutathione and dithiothreitol, suggesting that NiCl2-induced renal cell injury is dependent on thiols. However, such injury is not dependent solely on thiols, because (a) these thiols failed to inhibit completely the uptake of Ni2+ by the renal cortex, and (b) diethylmaleate pretreatment failed to increase NiCl2-induced cell injury further. Superoxide dismutase partially reduced the NiCl2-induced LDH release without affecting LPO and glutathione, whereas catalase did not affect such LDH release and LPO. Dimethylthiourea and DMSO completely prevented NiCl2-induced LPO, but only partially reduced LDH release. Deferoxamine prevented NiCl2-induced renal cell injury without affecting LPO and without significantly reducing Ni2+ uptake by the renal cortex, suggesting that nickel chelation is not important in such prevention of injury. NiCl2-induced inhibition of para-aminohippurate uptake was prevented significantly by thiols, deferoxamine, and dimethylthiourea. NiCl2-induced loss of cellular glutathione content was prevented significantly by thiols and deferoxamine, but not by superoxide dismutase and dimethylthiourea. These results suggest that LPO was not related to NiCl2-induced lethal renal cell injury, whereas such injury may be caused by the induction of the Fenton reaction, generating hydroxyl radicals.

Gadolinium induces domain and pore formation of human erythrocyte membrane: an atomic force microscopic study

Lanthanide cations bind to human erythrocyte membranes and enhance cell permeability. It was postulated that this effect is due to their likeness with calcium ions, which have been used to induce perforation of cells. However, the nature and mechanism of the perforation are still not clear. In the present work, the change in surface topography of erythrocyte membranes exposed to various gadolinium species was imaged with an atomic force microscope (AFM) in order to get direct evidence of perforation. The images of the whole cell and regions in nanometer scale showed that the normal surface is featured by closely packed nanometer size particles. The AFM images showed that Gd(3+) binding to erythrocytes led to domain structure at low concentration and pore formation at higher concentration. The domain structures that appeared after incubation with 1.0x10(-6)-1.0x10(-5) mol/l Gd(3+) solution for 30 min are featured by the particles aggregated to form ranges and the separations among them enlarged to gorges. With a higher concentration, 2.5x10(-5) mol/l Gd(3+), the further aggregation developed into crater-shaped 'pores'. By washing with EDTA the 'pores' can be resealed but the domain structure remained. The anionic complex of Gd(3+), [Gd(Cit)(2)](3-) of this concentration, can only induce the domain structure formation. The domain and 'pore' structures mediated by Gd(3+) concentrations might be responsible for both enhanced permeability and perforation. The mechanism of Gd-induced domain formation and perforation is discussed on the basis of aggregation of membrane proteins and the coexistence of different phases of membrane lipids resulting from Gd(3+) binding.

Activation and fragmentation of Bacillus thuringiensis delta-endotoxin by high concentrations of proteolytic enzymes

Commercial enzymes and insect gut juice at various concentrations were used to digest Bacillus thuringiensis subsp. sotto Cry1Aa protoxin and examine the fragmentation pattern and effect on insecticidal activity. Trypsin at both high (5 mg/mL) and low (0.05 mg/mL) concentrations converted protoxin to toxin with no difference in insecticidal activity against Bombyx mori larvae. In both cases, the toxin protein had an apparent M(r) of 58.4 kDa (SDS-PAGE). Active toxin of identical M(r) was also produced with low concentrations of Pronase and subtilisin, but at high concentration, it was degraded into two protease-resistant fragments of apparent M(r) 31.8 and 29.6 kDa, and exhibited no insecticidal activity. Sequencing data established the primary cleavage site to be in domain II, the receptor-binding region of the toxin, in an exposed loop between two beta-sheet strands. Fragmentation was not observed, however, when the digests were analyzed by native protein techniques, but rather the toxin molecule appeared to be intact. The amount of activated toxin produced by Choristoneura fumiferana gut juice was markedly reduced when the gut-juice concentration was increased from 1 to 50% and correlated with a loss in insecticidal activity. However, no lower M(r) protease-resistant fragments were evident in the SDS-PAGE of these digests.

Single molecule physics and chemistry

New experiments using scanning probe microcopies and advanced optical methods allow us to study molecules as individuals, not just as populations. The findings of these studies not only include the confirmation of results expected from studies of bulk matter, but also give substantially new information concerning the complexity of biomolecules or molecules in a structured environment. The technique lays the groundwork for achieving the control of an individual molecule's motion. Ultimately, this work may lead to such practical applications as miniaturized sensors.

Crystallization and preliminary X-ray diffraction studies of monomeric isocitrate dehydrogenase from Corynebacterium glutamicum

A monomeric isocitrate dehydrogenase has been crystallized for the first time. This enzyme catalyzes the conversion of isocitrate to oxalosuccinate and subsequently to alpha-ketoglutarate and CO(2); the coenzyme NADP(+) is reduced to NADPH during the reaction. Polyethylene glycol 2000 monomethyl ether was used to crystallize the enzyme in space group C2 with unit-cell parameters a = 137.1, b = 54.6, c = 126.4 A, beta = 108.2 degrees. The very small crystal (0. 05 x 0.20 x 0.05 mm) diffracted to 3.5 A d spacing using synchrotron radiation.

A projector/backprojector with slice-to-slice blurring for efficient three-dimensional scatter modeling

Scatter correction is an important factor in single photon emission computed tomography (SPECT). Many scatter correction techniques, such as multiple-window subtraction and intrinsic modeling with iterative algorithms, have been under study for many years. Previously, we developed an efficient slice-to-slice blurring technique to model attenuation and system geometric response in a projector/backprojector pair, which was used in an ML-EM algorithm to reconstruct SPECT data. This paper proposes a projector/backprojector that models the three-dimensional (3-D) first-order scatter in SPECT, also using an efficient slice-to-slice blurring technique. The scatter response is estimated from a known nonuniform attenuation distribution map. It is assumed that the probability of detection of a first-order scattered photon from a photon that is emitted in a given source voxel and scattered in a given scatter voxel is proportional to the attenuation coefficient value at that voxel. Monte Carlo simulations of point sources and an MCAT torso phantom were used to verify the accuracy of the proposed projector/backprojector model. An experimental Jaszczak torso/cardiac phantom SPECT study was also performed. For a 64 x 64 x 64 image volume, it took 8.7 s to perform each iteration per slice on a Sun ULTRA Enterprise 3000 (167 MHz, 1 Gbyte RAM) computer, when modeling 3-D scatter, attenuation, and system geometric response functions. The main advantage of the proposed method is its easy implementation and the possibility of performing reconstruction in clinically acceptable time.

Toxicity and bioaccumulation of nickel sulfate in Sprague-Dawley rats following 13 weeks of subchronic exposure

Adult male Sprague-Dawley rats were given 0, 0.02, 0.05, and 0.1% nickel sulfate (NiSO4-6H2O) or 0, 44.7, 111.75, and 223.5 mg Ni/L, respectively, in their drinking water for 13 wk. Twenty-four hours following the end of such treatment, all animals survived and no apparent clinical signs of toxicity were noted. The final mean body weights of various nickel sulfate-treated rats were not significantly decreased except for the 0.1% nickel sulfate treated group when compared to those in the control. The absolute and relative organ weights were either increased or decreased or remained unchanged, depending on the organ and the dose of nickel sulfate. Total plasma proteins, plasma albumin and globulins, and plasma glutamic pyruvic transaminase activity were all significantly decreased in 0.1% nickel sulfate-treated rats. Lymphocyte subpopulations (T and B cells) were induced at lower dose levels, but suppressed at the highest (0.1%) dose group. A significant decrease in urine volume and an increase in BUN were observed at the highest dose group. Biochemical analysis of bronchoalveolar lavage fluid and lung tissue showed some lung damage, whereas no damage to the testis or DNA in liver and kidneys were found. No gross or microscopic changes were seen in any of the various tissues examined. The relative order of bioaccumulation of nickel in different organs of rats when treated at 0.1% nickel sulfate (223.5 mg Ni/L) was kidneys > testes > lung = brain > spleen > heart = liver. But with regard to order of toxicity, both immune and pulmonary systems were found to be very sensitive targets, followed by kidney.

Characterization of the human cysteinyl leukotriene CysLT1 receptor

The cysteinyl leukotrienes-leukotriene C4(LTC4), leukotriene D4(LTD4) and leukotriene E4(LTE4)-are important mediators of human bronchial asthma. Pharmacological studies have determined that cysteinyl leukotrienes activate at least two receptors, designated CysLT1 and CysLT2. The CysLT1-selective antagonists, such as montelukast (Singulair), zafirlukast (Accolate) and pranlukast (Onon), are important in the treatment of asthma. Previous biochemical characterization of CysLT1 antagonists and the CysLT1 receptor has been in membrane preparations from tissues enriched for this receptor. Here we report the molecular and pharmacological characterization of the cloned human CysLT1 receptor. We describe the functional activation (calcium mobilization) of this receptor by LTD4 and LTC4, and competition for radiolabelled LTD4 binding to this receptor by the cysteinyl leukotrienes and three structurally distinct classes of CysLT1-receptor antagonists. We detected CysLT1-receptor messenger RNA in spleen, peripheral blood leukocytes and lung. In normal human lung, expression of the CysLT1-receptor mRNA was confined to smooth muscle cells and tissue macrophages. Finally, we mapped the human CysLT1-receptor gene to the X chromosome.

Purification and stabilization of a monomeric isocitrate dehydrogenase from Corynebacterium glutamicum

Monomeric isocitrate dehydrogenase was expressed in Corynebacterium glutamicum cells harboring pEK-icdES1, a plasmid carrying the gene for the enzyme. Two- to three-fold higher expression levels of the recombinant enzyme were observed in such cells when grown in fermentors, compared to those grown in shaker incubators. The enzyme was purified to homogeneity by ammonium sulfate fractionation, Sephadex G-150 gel filtration, FPLC Mono Q anion-exchange chromatography, and affinity gel chromatography. Approximately 4 mg of 98% pure recombinant enzyme was obtained per liter of bacterial culture. Our results also include optimum buffer conditions for purification and storage of the enzyme.

Identification of two hERR2-related novel nuclear receptors utilizing bioinformatics and inverse PCR

Identification of novel nuclear receptors based on the highly conserved DNA-binding domain (DBD) has previously depended mainly on low stringency hybridization of cDNA libraries and degenerate PCR. Establishment of the expressed sequence tag (EST) database in recent years has provided an alternative approach for the discovery of novel members of gene families. The rate-limiting step is the conversion of ESTs to full-length cDNA. This article describes the identification of two novel nuclear receptors (hERRbeta2 and hERRgamma2) related to human estrogen-receptor-related receptor 2 (hERR2) by mining the EST database and retrieving of full-length cDNA via inverse PCR on subdivided primary cDNA library pools. The deduced protein sequences of hERRbeta2 and hERRgamma2 contain 500 and 458 amino acid (aa) residues respectively. Sequence analysis revealed that hERRbeta2 and hERRgamma2 respectively share 95% and 77% overall aa sequence identity with hERR2. However, the extra C-terminal domain in hERRbeta2 and extra N-terminal domain in hERRgamma2 are not present in the closely related hERR2 or mouse ERR2 (mERR2). Extensive sequence verification revealed that hERR2 previously reported as a human gene is actually a rat gene, whereas hERRbeta2 is the true human ortholog of hERR2 and mERR2. Tissue distribution studies showed that hERRgamma2 was expressed in a broader panel of tissues at a higher level than hERRbeta2. hERRbeta2 was mapped to cytogenetic locus 14q24.3 approximately -14q31, a region containing multiple loci involved in genetic diseases, including Alzheimer and diabetes. hERRgamma2 was mapped to 1q32. Given the high sequence homology between hERRbeta2 and mERR2, the two receptors may have similar biological function in vivo.

Lung fluid transport in aquaporin-1 and aquaporin-4 knockout mice

The mammalian lung expresses water channel aquaporin-1 (AQP1) in microvascular endothelia and aquaporin-4 (AQP4) in airway epithelia. To test whether these water channels facilitate fluid movement between airspace, interstitial, and capillary compartments, we measured passive and active fluid transport in AQP1 and AQP4 knockout mice. Airspace-capillary osmotic water permeability (Pf) was measured in isolated perfused lungs by a pleural surface fluorescence method. Pf was remarkably reduced in AQP1 (-/-) mice (measured in cm/s x 0.001, SE, n = 5-10: 17 +/- 2 [+/+]; 6.6 +/- 0.6 AQP1 [+/-]; 1.7 +/- 0.3 AQP1 [-/-]; 12 +/- 1 AQP4 [-/-]). Microvascular endothelial water permeability, measured by a related pleural surface fluorescence method in which the airspace was filled with inert perfluorocarbon, was reduced more than 10-fold in AQP1 (-/-) vs. (+/+) mice. Hydrostatically induced lung interstitial and alveolar edema was measured by a gravimetric method and by direct measurement of extravascular lung water. Both approaches indicated a more than twofold reduction in lung water accumulation in AQP1 (-/-) vs. (+/+) mice in response to a 5- to 10-cm H2O increase in pulmonary artery pressure for five minutes. Active, near-isosmolar alveolar fluid absorption (Jv) was measured in in situ perfused lungs using 125I-albumin as an airspace fluid volume marker. Jv (measured in percent fluid uptake at 30 min, n = 5) in (+/+) mice was 6.0 +/- 0.6 (37 degrees C), increased to 16 +/- 1 by beta-agonists, and inhibited to less than 2.0 by amiloride, ouabain, or cooling to 23 degrees C. Jv (with isoproterenol) was not affected by aquaporin deletion (18.9 +/- 2.2 [+/+]; 16.4 +/- 1.5 AQP1 [-/-]; 16.3 +/- 1.7 AQP4 [-/-]). These results indicate that osmotically driven water transport across microvessels in adult lung occurs by a transcellular route through AQP1 water channels and that the microvascular endothelium is a significant barrier for airspace-capillary osmotic water transport. AQP1 facilitates hydrostatically driven lung edema but is not required for active near-isosmolar absorption of alveolar fluid.

DNA-Protein crosslinks induced by nickel compounds in isolated rat renal cortical cells and its antagonism by specific amino acids and magnesium ion

Suspensions of isolated renal cortical cells in modified Krebs-Henseleit buffer (pH 7.4) were incubated with nickel chloride, nickel acetate, nickel sulfate, and nickel subsulfide (0-2 mM) at 37 degreesC for 2 h. A significant increase (63%) in DNA-protein crosslinks was observed at 2 mM nickel sulfate, whereas nickel subsulfide induced a significant increase in such crosslinks beginning at 0.5 mM concentration and a maximum increase of 200% of the control value reached at 2 mM concentration. No significant reduction in viability of renal cortical cells (as measured by trypan blue exclusion) was observed due to these nickel compounds at any concentration used. In the second series of experiments, coincubation of nickel subsulfide (2 mM) with l-histidine (8 or 16 mM), l-cysteine (4 or 8 mM), or l-aspartic acid (8 or 24 mM) significantly reduced the DNA-protein crosslinks induced by 2 mM nickel subsulfide. Similarly Mg2+ (24 mM), but not Ca2+ (24 mM), was able to antagonize nickel subsulfide-induced increase in DNA-protein crosslinks. High extracellular levels of Mg2+ and these amino acids significantly decreased the accumulation of Ni2+ from nickel subsulfide in renal cortical cells. Furthermore, these amino acids at high concentrations significantly inhibited the binding of Ni2+ from nickel subsulfide to deproteinized DNA from renal cortical cells, whereas such inhibition due to Mg2+ was close to significant (0.1 > p > 0.05). In vitro exposures of renal cortical cells to nickel subsulfide (0-2 mM) increased the formation of reactive oxygen species in concentration-dependent manner. Furthermore, coincubation of 2 mM nickel subsulfide with either catalase, dimethylthiourea, mannitol, or vitamin C at 37 degreesC for 2 h resulted in a significant decrease of nickel subsulfide-induced formation of DNA-protein crosslinks, suggesting that nickel subsulfide-induced DNA-protein crosslink formation in isolated rat renal cortical cells is caused by the formation of reactive oxygen species. The potent protective effects of these specific amino acids and Mg2+ against nickel subsulfide-induced DNA-protein crosslink formation in isolated renal cortical cells are due to reduction of cellular uptake of Ni2+ and inhibition of the binding of Ni2+ to deproteinized DNA.