Identification and pharmacological characterization of the prostaglandin FP receptor and FP receptor variant complexes

Background and purpose: A prostamide analogue, bimatoprost, has been shown to be effective in reducing intraocular pressure, but its precise mechanism of action remains unclear. Hence, to elucidate the molecular mechanisms of this effect of bimatoprost, we focused on pharmacologically characterizing prostaglandin FP receptor (FP) and FP receptor variant (altFP) complexes.

Experimental approach: FP receptor mRNA variants were identified by reverse transcription-polymerase chain reaction. The FP-altFP4 heterodimers were established in HEK293/EBNA cells co-expressing FP and altFP4 receptor variants. A fluorometric imaging plate reader was used to study Ca²⁺ mobilization. Upregulation of cysteine-rich angiogenic protein 61 (Cyr61) mRNA was measured by Northern blot analysis, and phosphorylation of myosin light chain (MLC) by western analysis.

Key results: Six splicing variants of FP receptor mRNA were identified in human ocular tissues. Immunoprecipitation confirmed that the FP receptor is dimerized with altFP4 receptors in HEK293/EBNA cells co-expressing FP and altFP4 receptors. In the studies of the kinetic profile for Ca²⁺ mobilization, prostaglandin F_2α (PGF_2α) elicited a rapid increase in intracellular Ca²⁺ followed by a steady state phase. In contrast, bimatoprost elicited an immediate increase in intracellular Ca²⁺ followed by a second phase. The prostamide antagonist, AGN211335, selectively and dose-dependently inhibited the bimatoprost-initiated second phase of Ca²⁺ mobilization, Cyr61 mRNA upregulation and MLC phosphorylation, but did not block the action of PGF_2α.

Conclusion and implications: Bimatoprost lacks effects on the FP receptor but may interact with the FP-altFP receptor heterodimer to induce alterations in second messenger signalling. Hence, FP-altFP complexes may represent the underlying basis of bimatoprost pharmacology.

Phase stability and pressure dependence of defect formation in Gd2Ti2O7 and Gd2Zr2O7 pyrochlores

We report dramatically different behaviors between isostructural Gd2Ti2O7 and Gd2Zr2O7 pyrochlore at pressures up to 44 GPa, in which the substitution of Ti for Zr significantly increases structural stability. Upon release of pressure, the Gd2Ti2O7 becomes amorphous. In contrast, the high-pressure phase of Gd2Zr2O7 transforms to a disordered defect-fluorite structure. First-principle calculations for both compositions revealed that the response of pyrochlore to high pressure is controlled by the intrinsic energetics of defect formation.

1,3,5-Tris(6-chloropyrazin-2-yloxy)benzene

In the title compound, C₁₈H₉Cl₃N₆O₃, all bond lengths and angles are normal. The dihedral angles between the benzene ring and the three pyrazine rings are 72.67 (2), 60.73 (3) and 77.74 (2)°. The crystal packing is stabilized by van der Waals forces and by a weak π–π stacking inter­action between pyrazine rings, with a centroid–centroid distance of 3.487 (2) Å.

Locally applied simvastatin promotes fracture healing in ovariectomized rat

Simvastatin solution was injected subcutaneously to the site of fractured tibiae of ovariectomized rats. Afterwards healing quality was evaluated by morphologic, radiographic, biomechanical, histological and histomorphometric methods at 1, 2 and 4 weeks after fracture. Results showed that locally applied simvastatin improved fracture healing.

INTRODUCTION

Many studies have documented an anabolic effect of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, statins, on undisturbed bone. Reports of their effects, however, on fractured skeletal systems have been limited. A study was, therefore, conducted to check the effects of statins on fracture healing.

METHODS

Simvastatin (10 mg/kg/day) was injected subcutaneously to tissue overlying the site of fractured tibiae of ovariectomized rats for a treatment period of 5 days. Vehicle reagent was used as a control. Healing quality was evaluated at 1, 2 and 4 weeks after fracture.

RESULTS

Compared with that in the vehicle group, the callus cross-section area in simvastatin-treated rats was significantly enlarged by 21.3% (p < 0.05) at 1 week and by 21.5% (p < 0.05) at 2 weeks; new woven bone was relatively substantive and arranged more tightly and regularly at 2 and 4 weeks; and maximal load was increased by 57.5% (p < 0.05) at 2 weeks and by 31.4% (p < 0.05) at 4 weeks. Histomorphometrically, simvastatin was associated with a significant (p < 0.05) increase of mineralization width (MLW), mineralization volume (MLV) and mineral apposition rate (MAR).

CONCLUSION

The current study suggests that local application of simvastatin could promote fracture healing in ovariectomized rats.

[Roles of infochemicals in host-selection process of Anastatus japonicus]

By using a Y-tube olfactometer, this paper studied the selection behavior's responses of Anastatus japonicus to the volatiles and their individual components emitted from isolated leaves and live plants of different litchi varieties, and to Tessaratoma papillosa. The results showed that among the test litchi varieties, Sanyuehong and Huaizhi had more significant attracting effects to A. japonicus than Nuomici, Guiwei, Feizixiao and Heiye. The two main components of the volatiles from litchi leaves, alpha-humulene and beta-caryophyllene, had no distinct attraction to A. japonicus, but displayed synergistic effect on the host-searching process of natural enemy. When the two components were mixed in equal concentration of 0.3 microl x microl(-1), the attracting effect was most remarkable. In a dual-choice experiment, the selectivity of A. japonicus to T. papillosa eggs was not significant, but very remarkable to T. papillosa female adults and to the water extracts from adult abdomen-tip. In a vessel experiment, the numbers of A. japonicus which made selection to T. papillosa eggs and the settling frequency of A. japonicus on the place of T. papillosa eggs were more than those of other treatments. (E)-2-hexenal, one of the most important components of the volatiles of T. papillosa adult, didn't have evident attracting effect on the adults of A. japonicus.

Verrucotoxin inhibits KATP channels in cardiac myocytes through a muscarinic M3 receptor-PKC pathway

Verrucotoxin is the major component of venom from the stonefish (Synanceia verrucosa). Stings from the dorsal spines of the stonefish produce intensive pain, convulsions, hypotension, paralysis, respiratory weakness and collapse of the cardiovascular system, occasionally leading to death. It has been reported that verrucotoxin might modulate ATP-sensitive K+ (KATP) current in frog atrial fibers. However, the mechanism by which verrucotoxin acts on KATP current remains unclear. In this study, we examined whether verrucotoxin inhibited KATP current in guinea pig ventricular myocytes, using the patch clamp method. Verrucotoxin suppressed KATP current induced by pinacidil (KATP channel opener) in a concentration-dependent manner, with a half maximum concentration of 16.3 microg/ml. The effect of verrucotoxin on KATP current was suppressed by atropine (1 microM), a muscarinic receptor antagonist, or by 4-diphenylacetoxy-N-methylpiperidine (100 nM), a muscarinic M3 receptor antagonist. Furthermore, the effect of verrucotoxin on KATP current was attenuated by the protein kinase C (PKC) inhibitor chelerythrine (10 microM) and calphostin C (10 microM), yet not by the cAMP-dependent protein kinase (PKA) inhibitor H-89 (0.5 microM). These results suggest that verrucotoxin inhibits KATP current through the muscarinic M3 receptor-PKC pathway. These findings enhance our understanding of the toxic effects of verrucotoxin from the stonefish.

Identification of an antagonist that selectively blocks the activity of prostamides (prostaglandin-ethanolamides) in the feline iris

BACKGROUND AND PURPOSE

The prostamides (prostaglandin-ethanolamides) and prostaglandin (PG) glyceryl esters are biosynthesized by COX-2 from the respective endocannabinoids anandamide and 2-arachidonyl glycerol. Agonist studies suggest that their pharmacologies are unique and unrelated to prostanoid receptors. This concept was further investigated using antagonists.

EXPERIMENTAL APPROACH

The isolated feline iris was used as a key preparation, where prostanoid FP receptors and prostamide activity co-exist. Activity at human recombinant FP and other prostanoid receptors was determined using stable transfectants.

KEY RESULTS

In the feline iris, AGN 204396 produced a rightward shift of the dose-response curves for prostamide F2alpha and the prostamide F2alpha analog bimatoprost but did not block the effects of PGF2alpha and synthetic FP receptor agonists. Studies on human recombinant prostanoid receptors confirmed that AGN 204396 did not behave as a prostanoid FP receptor antagonist. AGN 204396 exhibited no antagonism at DP and EP1-4, but was a highly effective TP receptor antagonist. Contrary to expectation, the FP receptor antagonist AL-8810 efficaciously contracted the cat iris. AGN 204396 did not affect AL-8810 induced contractions, demonstrating that AL-8810 and AGN 204396 are pharmacologically distinct. Unlike AL-8810, the ethylamide derivate of AL-8810 was not an agonist. Al-8810 did not block prostamide F2alpha activity. Finally, AGN 204396 did not block PGE2-glyceryl ester activity.

CONCLUSIONS AND IMPLICATIONS

The ability of AGN 204396 to selectively block prostamide responses suggests the existence of prostamide sensitive receptors as entities distinct from receptors recognizing PGF2alpha and PGE2-glyceryl ester.

p38 Mitogen-activated protein kinases is required for counteraction of 2-methoxyestradiol to estradiol-stimulated cell proliferation and induction of apoptosis in ovarian carcinoma cells via phosphorylation Bcl-2

INTRODUCTION

2-Methoxyestradiol (2ME2), a natural endogenous product of estradiol (E2) metabolism, has been shown to be a selective apoptotic agent for cancer cells but not for normal cells. In this study, we determined that 2ME2 counteracts E2-stimulated cell growth and induces apoptosis in ovarian carcinoma cells. In addition, we demonstrate that 2ME2 induces apoptosis via p38 and phospho-Bcl2 pathway.

METHODS

2ME2 and/or E2 were administered to the OVCAR-3 (human ovarian cancer) cell line. Cell growth inhibition was analyzed by [3H] Thymidine incorporation assay and DNA fluorometric assay. Cell apoptosis was tested by DNA fragmentation analysis and FACS. The signaling pathway was determined by a series of biochemical assays.

RESULTS

2ME2 inhibited estradiol-stimulated cell growth and induced apoptosis in an ovarian carcinoma cell line. MAPK and p38, but not JNK, were found to be critical mediators in this process. Expression of a dominant negative mutant of p38 kinase or p38 specific inhibitor, SB 203580, almost completely blocked the process. Furthermore, Bcl-2 phosphorylation was required for 2ME2-induced effects.

CONCLUSION

Our data suggest that 2ME2 inhibits E2-stimulated proliferation and induces apoptosis in ovarian carcinoma cells. Furthermore, activation of p38 and phosphorylation of Bcl-2 plays a critical role in the mechanism. 2ME2 therefore, may have a clinical application for the treatment of ovarian cancer.

Changes in endocannabinoid and palmitoylethanolamide levels in eye tissues of patients with diabetic retinopathy and age-related macular degeneration

Cannabinoid receptors and the endocannabinoids (anandamide (N-arachidonoylethanolamine--AEA) and 2-arachidonoylglycerol (2-AG)), as well as the AEA congener, palmitoylethanolamide (PEA), are involved in ocular physiology. We measured endocannabinoid and PEA levels by isotope-dilution liquid chromatography-mass spectrometric analysis in post-mortem eye tissues of patients with diabetic retinopathy (DR) or age-related macular degeneration (AMD). In eyes with DR, significantly enhanced levels of AEA were found in the retina ( approximately 1.8-fold), ciliary body ( approximately 1.5-fold) and, to a lesser extent, cornea ( approximately 1.3-fold). Surprisingly, 2-AG levels were significantly higher ( approximately 3-fold) only in the iris, whereas PEA levels only slightly increased ( approximately 1.3-fold) in the ciliary body. In eyes with AMD, significantly enhanced levels of AEA were found in the choroid ( approximately 1.3-fold), ciliary body ( approximately 1.4-fold) and cornea ( approximately 1.4-fold), whereas in the retina only a trend towards an increase ( approximately 1.5-fold) was observed. The tissue- and disease-selective nature of the changes observed suggests that the compounds analyzed here may play different roles in the control of eye function under different pathological conditions.

Laccase production by Monotospora sp., an endophytic fungus in Cynodon dactylon

The effects of the carbon and nitrogen sources, initial pH and incubation temperature on laccase production by the endophytic fungus Monotospora sp. were evaluated. The optimal temperature and initial pH for laccase production by Monotospora sp. in submerged culture were found to be 30 degrees C and 8.5, respectively. Maltose (2 g l(-1)) and ammonium tartrate (10 g l(-1)) were the most suitable carbon and nitrogen source for laccase production. Under optimal culture medium, the maximum laccase activity was determined to be 13.55 U ml(-1), which was approximately four times higher than that in basal medium. This is the first report on laccase production by an endophytic fungus.

Gene profiling involved in immature CD4+ T lymphocyte responsible for systemic lupus erythematosus

We attempted to characterize the genes expression of CD4+ T lymphocytes for the pathogenesis of systemic lupus erythematosus (SLE). Genomewide gene expression profiles of CD4+ T cells, which were isolated from the disease severe activity (T4-1s) and nonactivity (T4-2s) with an SLE patient by using long serial analysis of gene expression (LongSAGE). We picked out 289 genes matching to Unigene cluster with different expression more than four copies between T4-1s and T4-2s libraries and analyzed their roles from the collectedly published articles of PubMed by genes functional clustering. The genes functions were related to a diverse cellular process including: (1) most of these genes were associated with CD4+ T cells functions, particularly related to cellular developments; (2) Ras pathway genes as RANBP10, GMIP, RASGRP2 and ARL5 might be responsible for the abnormal development of CD4+ T cells of SLE; (3) HIG2, TCF7, KHSRP, WWP1, SMAD3, TLK2, AES, CCNI and PIM2 belong to Wnt/beta-catenin way, they could play roles in modulating proliferation and differentiation of T lymphocytes; (4) uncertain viral infections may initiate autoimmunity because high levels expression genes were detected in T4-1s such as TRIM22, IER2, ABCE1, DUT, G1P2, G1P3, HNRPUL1, EVER2, IFNAR1, TNFSF14, TMP21 and PVRL2; and (5) apoptosis relating genes as EIF3S8, SH3BGRL3, GPX4, TOSO, PFDN5, BIN1, XIAPAF1, TEGT and CUGBP2 may contribute to over uploading of selfantigens in SLE cells. Abnormalities findings of multiple genes expression involving with a variety of CD4+ T cells process might be meaningful to understanding the pathogenesis of SLE, and immature CD4+ T cells may be responsible for SLE.

Herpes simplex virus 1 inhibits apoptosis through a caspase-3-dependent pathway in primary cultures of cortical neuronal cells of fetal mice

We could induce apoptosis in primary cultures of cortical neurons of fetal mice with ceramide or sorbitol. The induction was accompanied by an increase in caspase-3 (CAS-3) activity and depolarization of the inner mitochondrial membrane of neuronal cells which both could be reversed by Herpes simplex virus 1 (HSV-1) infection. We conclude tha HSV-1 infection inhibited the apoptosis, induced in neuronal cells by sorbitol or ceramide, via a CAS-dependent pathway.

Optimizing the error term in direct-method SAD phasing

The probability formula of the direct-method SAD (single-wavelength anomalous diffraction) phasing proposed by Fan & Gu (1985, Acta Cryst. A41, 280-284) contains an error term which is related to the lack-of-closure error. This error term is used as a weighting function in the phase derivation and in the subsequent calculation of electron-density maps. Previously, there has been a constant in the error term that has had to be determined empirically for each particular case. It has been found that improper choice of the constant often leads to failure of the direct-method SAD phasing. The problem is resolved by introducing a modified error term and a method of automatically tuning the associated scaling factor.

Direct-method SAD phasing with partial-structure iteration: towards automation

The probability formula of direct-method SAD (single-wavelength anomalous diffraction) phasing proposed by Fan & Gu (1985, Acta Cryst. A41, 280-284) contains partial-structure information in the form of a Sim-weighting term. Previously, only the substructure of anomalous scatterers has been included in this term. In the case that the subsequent density modification and model building yields only structure fragments, which do not straightforwardly lead to the complete solution, the partial structure can be fed back into the Sim-weighting term of the probability formula in order to strengthen its phasing power and to benefit the subsequent automatic model building. The procedure has been tested with experimental SAD data from two known proteins with copper and sulfur as the anomalous scatterers.

Contents of cesium, iodine, strontium, thorium, and uranium in selected human organs of adult asian population

Contents of cesium, iodine, strontium, thorium, and uranium in some selected human organs were estimated for adult Asian population using data obtained in four Asian countries: China, India, Philippines, and Republic of Korea, as part of a Coordinated Research Program of the International Atomic Energy Agency on "Ingestion and Organ contents of elements of importance in radiation protection." These countries together represent more than 40% of the world population. Highly sensitive analytical techniques were employed to measure cesium in skeletal muscle, iodine in thyroid, strontium in skeleton, thorium and uranium in skeleton, liver, kidneys, and lungs where, in comparison to other organs, these elements are present in higher concentrations. The organ contents for adult Asian population, when compared with the corresponding data proposed for Reference Man by International Commission on Radiological Protection (ICRP), showed about 40 times lower kidneys content and about 10 times lower skeleton content of uranium. The content of thorium in skeleton for Asian population was also half of the ICRP Reference Man value. Interestingly, organ contents for the other elements such as iodine in thyroid, cesium in skeletal muscle, and strontium in skeleton were comparable for Asian and the Caucasian population (represented by ICRP Reference Man). Organ contents for these elements were also calculated by applying the new ICRP models of these elements to their daily intakes. The comparison of the calculated and measured organ contents showed that despite uncertainties in the organ content values arising due to the inter-country variations in daily dietary intakes, the contents were within a factor of two to three. This observation is significant since human data both on organ contents and ingestion were obtained at environmental level of intakes. The study suggests that currently available ICRP models for these elements are quite realistic.

SAD phasing by combination of direct methods with the SOLVE/RESOLVE procedure

In the initial stage of SAD phasing, the essential point is to break the intrinsic phase ambiguity. The presence of two kinds of phase information enables the discrimination of phase doublets from SAD data prior to density modification. One is from the heavy atoms (anomalous scatterers), while the other is from the direct-methods phase relationships. The former can be expressed by the Sim distribution, while the latter can be expressed by the Cochran distribution. Typically, only the Sim distribution has been used to yield initial phases for subsequent density modification. However, it has been demonstrated that using direct-methods phases based on the product of the Sim and Cochran distributions can lead to improved initial phases. In this paper, the direct-methods phasing procedure OASIS has been improved and combined with the SOLVE/RESOLVE procedure. Experimental SAD data from three known proteins with expected Bijvoet ratios </DeltaF/>/<F> in the range 1.4-7.0% were used as test cases. In all cases, the phases obtained using the program RESOLVE beginning with initial phases based on experimental phases plus Sim and direct-methods information were more accurate than those based on experimental plus Sim phase information alone.

Binding pancreaticojejunostomy--a safe and reliable anastomosis procedure

BACKGROUND

Over the past one hundred years, the development of pancreaticoduodenectomy (PD) has always involved the struggle against pancreatic leakage. Until now, leakage of the pancreatic anastomosis has remained a common and serious complication after PD. Various methods of dealing with the pancreatic stump for prevention of pancreatic anastomotic leakage have been described. No matter which method is used, however, pancreatic anastomotic leakage is still most likely to occur when anastomosis involves a normal and soft pancreas.

METHODS

To perform a safe and reliable pancreaticoenteric anastomosis, we investigated the risk factors and potential mechanisms of occurrence of pancreatic leakage, including leakage from the needle hole and from the seam between two anastomosed structures, blood supply to the anastomosis and tension at the anastomosis. Based on these findings, we established a new pancreaticoenteric anastomosis procedure - binding pancreaticojejunostomy. The unique aspects of this procedure are as follows. The sero-muscular sheath of jejunum is bound to the invaginated pancreatic stump, so as to seal the gap between them; mucosa of the segment of jejunum that would eventually be in contact with the pancreatic stump is destroyed either chemically or by electric coagulation to promote healing. There is no needle hole on the jejunal surface of the anastomotic site.

RESULTS

From 1996 to 2003, a total of 227 consecutive patients were treated with this type of pancreaticojejunostomy in this institution. None of the patients developed a pancreatic anastomotic leak.

DISCUSSION

Binding pancreaticojejunostomy is a safe and reliable anastomotic procedure to effectively minimize leakage even when the texture of the pancreas is soft and normal.

Estimation of internal radiation dose to the adult Asian population from the dietary intakes of two long-lived radionuclides

Daily dietary intakes of two naturally occurring long-lived radionuclides, 232Th and 238U, were estimated for the adult population living in a number of Asian countries, using highly sensitive analytical methods such as instrumental and radiochemical neutron activation analysis (INAA and RNAA), and inductively coupled plasma mass spectrometry (ICP-MS). The Asian countries that participated in the study were Bangladesh (BGD), China (CPR), India (IND), Japan (JPN), Pakistan (PAK), Philippines (PHI), Republic of Korea (ROK) and Vietnam (VIE). Altogether, these countries represent more than 50% of the world population. The median daily intakes of 232Th ranged between 0.6 and 14.4 mBq, the lowest being for Philippines and the highest for Bangladesh, and daily intakes of 238U ranged between 6.7 and 62.5 mBq, lowest and the highest being for India and China, respectively. The Asian median intakes were obtained as 4.2 mBq for 232Th and 12.7 mBq for 238U. Although the Asian intakes were lower than intakes of 12.3 mBq (3.0 ug) 232Th and 23.6 mBq (1.9 ug) 238U proposed by the International Commission on Radiological Protection (ICRP) for the ICRP Reference Man, they were comparable to the global intake values of 4.6 mBq 232Th and 15.6 mBq 238U proposed by the United Nation Scientific Commission on Effects of Radiation (UNSCEAR). The annual committed effective doses to Asian population from the dietary intake of 232Th and 238U were calculated to be 0.34 and 0.20 microSv, respectively, which are three orders of magnitude lower than the global average annual radiation dose of 2400 microSv to man from the natural radiation sources as proposed by UNSCEAR.

Cladistic analysis of iridoviruses based on protein and DNA sequences

Cladograms of iridoviruses were inferred from bootstrap analysis of molecular data sets comprising all published protein and DNA sequences of the major capsid protein, ATPase and DNA polymerase genes of members of the Iridoviridae family Iridovirus. All data sets yielded cladograms supporting the separation of the Iridovirus, Ranavirus and Lymphocystivirus genera, and the cladogram based on data derived from major capsid proteins further divided both the Iridovirus and Ranavirus genera into two groups. Tests of alternative hypotheses of topological constraints were also performed to further investigate relationships between infectious spleen and kidney necrosis virus (ISKNV), an unclassified fish iridovirus for which the complete genome sequence data is available, and other iridoviruses. Cladograms inferred and results of Shimodaira-Hasegawa tests indicated that ISKNV is more closely related to the Ranavirus genus than it is to the other genera of the family.

Outcome of calf deep-vein thrombosis after total knee arthroplasty

We investigated the outcome of deep-vein thrombosis (DVT) in the calf after total knee arthroplasty (TKA) in 48 patients (45 women and three men) by clinical assessment and venographic study between three and four years after surgery. The mean age of the patients was 67.2 +/- 7.7 years (52 to 85) and the mean follow-up was 42.6 +/- 2.7 months (38 to 48). The diagnosis was osteoarthritis in 47 patients and rheumatoid arthritis in one patient. There were 44 calf thrombi, four popliteal thrombi but no thrombi in the femoral or iliac regions. Of the 48 patients, 24 were clinically symptomatic and 24 were asymptomatic. Clinical examination was carried out on 41 patients, of whom 37 underwent ascending venography. Seven were evaluated by telephone interview. No patient had the symptoms or signs of recurrent DVT, venous insufficiency in the affected leg, or a history of pulmonary embolism. No patient had been treated for complications of their DVT. Thirty-six of the 37 venographic studies were negative for either old or new DVT in the affected leg. One patient had residual thrombi in the muscular branches of the veins. Our study shows that deep-vein thromboses in the calf after TKA disappear spontaneously with time. No patient developed a recurrent DVT, proximal propagation or embolisation. Treatment of DVT in the calf after TKA should be based on the severity of the symptoms during the immediate postoperative period.

Mechanism of bradykinin-induced Ca(2+) mobilization in MG63 human osteosarcoma cells

BACKGROUND

The effect of bradykinin on intracellular free Ca(2+) levels ([Ca(2+)](i)) in MG63 human osteosarcoma cells was explored using fura-2 as a Ca(2+) dye.

METHODS/RESULTS

Bradykinin (0.1 nM-1 microM) increased [Ca(2+)](i) in a concentration-dependent manner with an EC(50) value of 0.5 nM. The [Ca(2+)](i) signal comprised an initial peak and a fast decay which returned to baseline in 2 min. Extracellular Ca(2+) removal inhibited the peak [Ca(2+)](i )signals by 35 +/- 3%. Bradykinin (1 nM) failed to increase [Ca(2+)](i) in the absence of extracellular Ca(2+ )after cells were pretreated with thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor; 1 microM). Bradykinin (1 nM)-induced intracellular Ca(2+) release was nearly abolished by inhibiting phospholipase C with 2 microM 1-(6-((17 beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122). The [Ca(2+)](i )increase induced by 1 nM bradykinin in Ca(2+)- free medium was abolished by 1 nM HOE 140 (a B2 bradykinin receptor antagonist) but was not altered by 100 nM Des-Arg-HOE 140 (a B1 bradykinin receptor antagonist). Pretreatment with 1 pM pertussis toxin for 5 h in Ca(2+) medium inhibited 30 +/- 3% of 1 nM bradykinin-induced peak [Ca(2+)](i) increase.

CONCLUSIONS

Together, this study shows that bradykinin induced [Ca(2+)](i) increases in a concentration-dependent manner, by stimulating B2 bradykinin receptors leading to mobilization of Ca(2+) from the thapsigargin-sensitive stores in a manner dependent on inositol-1,4,5-trisphosphate, and also by inducing extracellular Ca(2+) influx. The bradykinin response was partly coupled to a pertussis toxin-sensitive G protein pathway.

Experience with a bone bank operation and allograft bone infection in recipients at a medical centre in southern Taiwan

To assess the contamination rate of allograft bones at retrieval and the infection rate of the implanted allograft bone, we audited a bone bank retrospectively and reviewed the medical charts of allograft bone recipients between June 1999 and June 2000 at a medical centre in southern Taiwan. The bone bank did its utmost to minimize allograft contamination with hospital-acquired pathogens by adopting purposefully designed criteria for selection of donors. This protocol included sterilization with soaking of the retrieved allograft in a solution of a first-generation cephalosporin before storage and prophylaxis in recipients with first-generation cephalosporin. The contamination rates at allograft retrieval from living and cadaveric donors were 2.7% and 12.4%, respectively (P<0.001). Culture of 262 specimens taken at allograft implant revealed 12 (4.6%) positive for culture. Of the 12 patients implanted with allograft bones positive for culture, nine (75.0%) had allograft bone infection, while three (25.0%) did not. Among the 250 recipients with sterile allograft bones, four (1.6%) were found to have allograft infection. None of the cases of infection required removal of the allograft bones, and all cases were successfully treated with tailored antimicrobial therapy based on susceptibility tests on isolated bacteria. The overall infection rate was 5.0%, which compared favourably with those in other series. A prospective cohort study is needed to determine which of the varied sterilization methodologies gives the best and/or most cost-effective outcome.

Pilot study of in-situ thermal treatment for the remediation of pentachlorophenol-contaminated aquifers

A field pilot study of a steam injection method for the treatment of pentachlorophenol (PCP)-contaminated soil and groundwater has shown potential advantages over the traditional pump-and-treatment method. Low-pressure steam was injected 10 m below the ground surface. The ground water temperature was raised to 118 degrees C over a period of 3 months. Five soil and groundwater sampling events were performed during the pilot test. Results of sample analysis showed that the PCP concentrations in deep aquifer soil decreased dramatically whereas those in shallow aquifer soil increased. It was concluded that raising the groundwater temperature caused PCP in deep aquifer soil to be desorbed, and as the hot, deep groundwater circulated upward, it brought the desorbed PCP to the shallow aquifer. By using steam injection, PCP can be desorbed from soil and moved upward to the ground surface so that it can be removed more easily through pump-and-treatment.

Expression of fas ligand in metastatic prostatic carcinoma: suggestive of possible clonal expansion of subpopulation with metastatic potential

Fas ligand (FasL) is a type II transmembrane tumor necrosis factor family protein, known to trigger apoptosis in cells that bear the FasL receptor, Fas. The authors found that normal prostate, benign hyperplasia, and most prostatic carcinoma cells at the primary site did not express FasL, whereas metastatic prostatic carcinoma cells in lymph nodes and bone marrow displayed almost uniform, immunohistochemically detectable, FasL expression. However, small foci of FasL-positive prostatic carcinoma cells amid a vast majority of FasL-negative tumor cells were noted at the primary sites in patients with distant metastases. Analysis of the FasL gene and its mRNA by polymerase chain reaction and reverse transcriptase-polymerase chain reaction, respectively, suggested that the expression of immunohistochemically detectable FasL in metastatic tumor cells was not due to mutation in the FasL gene with resulting overexpression. Further, FasL expression was detectable in the acinar epithelial cells of prostates with morphologic atrophic changes, suggesting that FasL also plays a role in the physiologic apoptosis process of noncancerous prostate. The current data suggest that a subpopulation of prostate carcinoma cells clonally expresses FasL, and this subpopulation may have metastatic potential. Evaluation of FasL expression in the primary tumor thus may provide a useful parameter for predicting metastatic potential of the tumor.