Intraocular lens power calculation after laser in situ keratomileusis for myopia and hyperopia: a standardized approach

PURPOSE

(1) To determine the effect of myopic and hyperopic laser in situ keratomileusis (LASIK) on calculation of intraocular lens (IOL) power. (2) To determine a standard way to approach the IOL power determination after LASIK, and (3) To compare different suggested methods.

METHODS

Biometric analysis and theoretical calculation of IOL powers for eyes undergoing LASIK for myopia and hyperopia were performed.

RESULTS

Manual keratometry after LASIK for myopia resulted in underestimation of IOL power. Manual keratometry after hyperopic LASIK resulted in overestimation of IOL power. The amount of error was directly related to the amount of correction by LASIK.

CONCLUSION

The pre-LASIK refraction can be used theoretically to determine an accurate IOL power.

Event history graphs for censored survival data

A compact graphical device for combining survival and time-varying covariate information is proposed. The proposed graph contains the Kaplan-Meier estimator for right-censored data and a simultaneous display of the behaviour of time-dependent covariate(s) and the lifetime for each subject in the sample. The observed levels of time-dependent covariates are possibly subjected to an initial dimension reduction or smoothing step to produce a continuous covariate function. Values of this function are plotted on a horizontal bar for the length of the lifetime of the subject. Covariate information for censored data is also incorporated. The union of the horizontal bars forms the Kaplan-Meier estimator of the survival function. Our graphical method is implemented with a new S-plus function and demonstrated in several applications.

Development of a system for in vitro neck muscle force replication in whole cervical spine experiments

STUDY DESIGN

An in vitro biomechanical study.

OBJECTIVES

To develop and evaluate a new in vitro whole cervical spine model that provides to the specimen, in vivo-like mechanical characteristics.

SUMMARY OF BACKGROUND DATA

In vitro studies of kinematics, kinetics, and trauma using isolated spine specimens (head-T1 vertebra) have usually applied upward force to the head, resulting in tensile spine forces, contrary to the physiological compressive forces present in vivo. Further, the in vitro load-displacement curves have never been compared with the corresponding in vivo data.

METHODS

A novel muscle force replication (MFR) system is presented. It consists of a set of compressive forces applied to the various vertebrae and occiput of a whole cervical spine specimen. Two protocols, with and without MFR, were evaluated using standardized flexibility testing. Ranges of motion (ROM) and load-displacement curves were documented, and contrasted with similar in vivo data.

RESULTS

Results for the MFR were found to be similar to the in vivo measurements, with respect to the intersegmental and whole neck motions as well as the load-displacement curves, thus validating the MFR approach.

CONCLUSIONS

The new model advances the in vitro testing, which uses whole cervical spine specimens.

Association of galectin-1 and galectin-3 with Gemin4 in complexes containing the SMN protein

In previous studies we showed that galectin-1 and galectin-3 are factors required for the splicing of pre-mRNA, as assayed in a cell-free system. Using a yeast two-hybrid screen with galectin-1 as bait, Gemin4 was identified as a putative interacting protein. Gemin4 is one component of a macromolecular complex containing approximately 15 polypeptides, including SMN (survival of motor neuron) protein. Rabbit anti-galectin-1 co-immunoprecipitated from HeLa cell nuclear extracts, along with galectin-1, polypeptides identified to be in this complex: SMN, Gemin2 and the Sm polypeptides of snRNPs. Direct interaction between Gemin4 and galectin-1 was demonstrated in glutathione S-transferase (GST) pull-down assays. We also found that galectin-3 interacted with Gemin4 and that it constituted one component of the complex co-immunoprecipitated with galectin-1. Indeed, fragments of either Gemin4 or galectin-3 exhibited a dominant negative effect when added to a cell-free splicing assay. For example, a dose-dependent inhibition of splicing was observed in the presence of exogenously added N-terminal domain of galectin-3 polypeptide. In contrast, parallel addition of either the intact galectin-3 polypeptide or the C-terminal domain failed to yield the same effect. Using native gel electrophoresis to detect complexes formed by the splicing extract, we found that with addition of the N-terminal domain the predominant portion of the radiolabeled pre-mRNA was arrested at a position corresponding to the H-complex. Inasmuch as SMN-containing complexes have been implicated in the delivery of snRNPs to the H-complex, these results provide strong evidence that galectin-1 and galectin-3, by interacting with Gemin4, play a role in spliceosome assembly in vivo.

Indirect electrochemical treatment of saline dyestuff wastewater

Dyestuff wastewater is always found to contain highly-concentrated sodium chloride. In many cases, biological processes are not available to dispose saline dyestuff wastewater. In this paper, both direct a nd indirect electrochemical oxidation of saline dyestuff wastewater were carried out and the accessibility of indirect electrochemical oxidation by electrochemically generated hypochlorite was investigated. It was found that the indirect electrochemical process removed COD by 87% and color by 100% in 50 minutes while the direct electrochemical process removed COD by 47% and color by 50% in 5 hours. The rate-limiting step for hypochlorite evolution at the anode was found to be diffusion-controlled. For the two processes, COD removal kinetics could be simplified as the pseudo first-order kinetics. The rate constants of COD removal were 0.038 min(-1) and 0.0018 min(-1) for the indirect and direct oxidation respectively. Current efficiency of the indirect process was I while that of the direct process was 0.16; cost efficiency of the two processes was 8,000 mg-COD (kWh)(-1) and 1,000 mg-COD (kWh)(-1) respectively. It can be concluded that the indirect electrochemical process is a promising method for the disposal of saline dyestuff wastewater.

Fendiline mobilizes intracellular Ca2+ in Chang liver cells

1. The effects of the antianginal drug fendiline (N-[3,3-diphenylpropyl]-alpha-methyl-benzylamine) on intracellular free Ca2+ levels ([Ca2+](i)) in Chang liver cells were evaluated using fura-2 as a fluorescent Ca2+ indicator. 2. Fendiline (1-100 micromol/L) increased [Ca2+](i) in a concentration-dependent manner, with an EC50 of 25 micromol/L. 3. The [Ca2+](i) response was composed of an initial rise and a slow decay to a sustained phase. Removal of extracellular Ca2+ partly reduced the [Ca2+](i) signals. 4. Fendiline (10 micromol/L)-induced release of intracellular Ca2+ was reduced by 65% following pretreatment with 1 micromol/L thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) to deplete Ca2+ stored in the endoplasmic reticulum. 5. After pretreatment with 10 micromol/L fendiline in Ca2+-free medium for several minutes, addition of 3 mmol/L Ca2+ induced an increase in [Ca2+](i) of a magnitude four-fold greater than control. This increase in [Ca2+](i) was not reduced by 10 micromol/L SKF96365, econazole, nifedipine or verapamil. 6. Fendiline (10 micromol/L)-induced release of intracellular Ca2+ was not altered by inhibition of phospholipase C with 2 micromol/L 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino) hexyl)-1H-pyrrole-2,5-dione (U73122). 7. The results of the present study show that fendiline induces an increase in [Ca2+](i) in Chang liver cells by releasing stored Ca2+ in an inositol 1,4,5-trisphosphate-independent manner and by causing extracellular Ca2+ influx.

A change-point model for reporting delays under change of AIDS case definition

Accurate monitoring of disease incidence is of major public health concern. The time delay between diagnosis and the date of reporting creates bias in estimating disease incidence. Changes in case definition are expected to have an impact on the time lag of case reporting. We propose a change-point model for reporting delays in AIDS that takes into account recent changes in the AIDS definition in US and European countries. The model was applied to California AIDS surveillance data and the distribution of reporting delays before and after the recent change of definition in 1993 were analyzed in terms of contributing factors. The overall significance of the model with change-point as compared to the model without change-point indicates that the effect of the 1993 change in definition on the distribution of reporting delays was highly significant (p < 0.0001). Overall, reporting delay of cases initially diagnosed with AIDS-defining diseases before 1993 was shorter compared to after 1993; reporting delay of cases initially diagnosed meeting the 1993 immunologic case definition was shorter than of those initially diagnosed with AIDS-defining diseases. Region of residence, mode of exposure, race/ethnicity and time of diagnosis emerged as the main covariates in the models. The method introduced here applies to current and possible future changes of the AIDS case definition as well as changes in diagnostic criteria or case definition in diseases other than AIDS. We demonstrate that such changes may be accompanied by sizeable changes in the distribution of reporting delays, and thus adjustment for reporting delays must be recalibrated after a change in definition.

An in vitro model for evaluation of vaporous toxicity of trichloroethylene and tetrachloroethylene to CHO-K1 cells

Toxicokinetics of trichloroethylene (TCE) and tetrachloroethylene (PER) in culture medium and their toxicity to CHO-K1 cells were investigated by employing an in vitro vapor exposure system. Cells were cultured in a 60 mm petri dish with a 25 mm glass dish glued in the central area. TCE or PER was added to the central glass dish so that it would evaporate and dissolve in the surrounding medium in which cells were growing. The results showed that the concentration of TCE or PER in medium increased significantly within 20 min and then decreased very rapidly with time. After a 24 h incubation, the residual of TCE or PER in the medium was very low, but was displayed in a dose-dependent manner. Treatment of cells with either TCE or PER resulted in a dose- and time-dependent inhibition of cell growth. A significantly increase in the frequency of micronuclei (MN) was also observed with either TCE or PER treatment. Low doses of TCE (5-20 microl) or PER (1-5 microl) significantly enhanced the intracellular glutathione (GSH) level. However, the level of GSH rapidly decreased with higher doses of TCE (40-80 microl) or PER (10-20 microl). Depletion of cellular GSH showed no effect on the sensitivity of cells to TCE or PER treatment. GSH-conjugation has been proposed as an activation mechanism to account for the nephrotoxicity of TCE and PER, however the toxicity of TCE and PER to CHO-K1 cells is probably mediated through a distinct mechanism.

Construction and validation of automated purge-and-trap-gas chromatography for the determination of volatile organic compounds

An automated purge-and-trap chromatographic system for the determination of dissolved volatile organic compounds in aqueous samples was built in the laboratory with minimum cost both in the construction and routine operation. This system was built upon a commercial gas chromatograph with full automation capability using self-developed hardware and software. The use of a multi-sorbent bed quantitatively trapped a wide range of volatile organic compounds at ambient temperature, including the extremely volatile ones such as dichlorofluoromethane (CFC-12). Flash heating for rapid desorption and adequate plumbing for minimizing dead volume resulted in excellent chromatographic separation at above-ambient temperatures, which eliminated the need for cryogen for cooling at the head of the column, a second refocusing stage, or entire GC oven for refocusing. This cryogen-free system was tested with standard solutions and environmental samples for determining hydrocarbons with flame ionization detection, and halogenated compounds with electron-capture detection. An innovative method was also developed for validating the system's linearity for extremely volatile compounds. By introducing ambient air, which usually contains constant levels of anthropogenic halocarbons, e.g., CFC-12 and CFC-11 (CCl3F), the need to prepare aqueous standards containing extremely volatile compounds is avoided, hence providing a convenient method for evaluating a purge-and-trap system.

CP55,940 increases intracellular Ca2+ levels in Madin-Darby canine kidney cells

The effect of CP55,940, a presumed CB1/CB2 cannabinoid receptor agonist, on intracellular free Ca2+ levels ([Ca2+]i) in Madin-Darby canine kidney cells was examined by using the fluorescent dye fura-2 as a Ca2+ indicator. CP55,940 (2-50 microM) increased [Ca2+]i concentration-dependently with an EC50 of 8 microM. The [Ca2+]i signal comprised an initial rise and a sustained phase. Extracellular Ca2+ removal decreased the maximum [Ca2+]i signals by 32+/-12%. CP55,940 (20 microM)-induced [Ca2+]i signal was not altered by 5 microM of two cannabinoid receptor antagonists, AM-251 and AM-281. CP55,940 (20 microM)-induced [Ca2+]i increase in Ca2+-free medium was inhibited by 86+/-3% by pretreatment with 1 microM thapsigargin, an endoplasmic reticulum Ca2+ pump inhibitor. Conversely, pretreatment with 20 microM CP55,940 in Ca2+-free medium for 6 min abolished thapsigargin-induced [Ca2+]i increases. CP55,940 (20 microM)-induced intracellular Ca2+ release was not inhibited when inositol 1,4,5-trisphosphate formation was abolished by suppressing phospholipase C with 2 microM U73122. Collectively, this study shows that CP,55940 induced significant [Ca2+]i increases in canine renal tubular cells by releasing stored Ca2+ from the thapsigargin-sensitive pools in an inositol 1,4,5-trisphosphate-independent manner, and also by causing extracellular Ca2+ entry. The CP55,940's action appears to be dissociated from stimulation of cannabinoid receptors.

Concentration variability of halocarbons over an electronics industrial park and its implication in compliance with the Montreal protocol

This work investigated fugitive emissions of anthropogenic halocarbons in a semiconductor and electronics industrial park in Taiwan using both flask and in-situ measurement methods. Large concentration variabilities in methylchloroform, trichloroethene, and tetrachloroethene suggested substantial usage and emissions in the industrial park. While the variability of CFC-113, CCl4, and CFC-11 was rather small using the flask sampling technique, the in-situ method with its higher frequency, however, showed significantly larger variability arising from observing periodic emission episodes, which were highly correlated with wind direction and topography of the park.

Alternative medicine use by individuals with major depression

OBJECTIVE

To describe the use of alternative medicine (AM) by persons with major depression and to examine the factors associated with AM use among these individuals.

METHODS

We used data from the 1994-1995 and 1996-1997 National Population Health Surveys. We selected subjects who had major depression according to the Composite International Diagnostic Interview Short Form for Major Depression (CIDI-SFMD). The prevalence of AM and conventional health service use by the subjects was calculated for each survey and was stratified by province. We employed logistic regression to examine the factors associated with AM use.

RESULTS

There was a temporal trend toward increasing use of AM among persons with major depression. The prevalence of AM use among subjects with major depression was 7.8% in 1994-1995 and 12.9% in 1996-1997. Female sex, having more than 12 years' education, and having 1 or more long-term medical conditions were associated with an increased likelihood of using AM. The sex difference in AM use depended on subjects' age in 1996-1997.

CONCLUSION

General practitioners, mental health specialists, and AM providers should be aware of their patients' use of both conventional medical services and AM because there may be interactions between conventional and alternative treatments. Communication and, if possible, cooperation may lead to improved outcomes in the management of depressive disorders.

Major depression and quality of life in individuals with multiple sclerosis

OBJECTIVE

To compare the Quality of Life (QOL) of multiple sclerosis (MS) patients with and without lifetime major depression.

METHOD

Data on 136 MS subjects sampled from the University of Calgary MS Clinic were collected. The WHO's Composite International Diagnostic Interview (CIDI) was used to diagnose lifetime major depression. The MSQOL-54 was administered to evaluate QOL of the subjects.

RESULTS

Thirty one (22.8 percent) of the 136 MS subjects had lifetime major depression, However, only 6 of these had a current episode at the time of data collection. MS patients with lifetime major depression had significantly lower MSQOL-54 scores in the QOL domains of Energy, Mental Health, Cognitive Function, General Quality of Life, Sexual Function, and Role Limitation-Emotional than the MS patients without lifetime major depression.

CONCLUSIONS

Lifetime major depression may have a substantial impact on the QOL of people with MS. Alternatively, MS patients with poor QOL may be at greater risk of major depression.

Evolution of digital organisms at high mutation rates leads to survival of the flattest

Darwinian evolution favours genotypes with high replication rates, a process called 'survival of the fittest'. However, knowing the replication rate of each individual genotype may not suffice to predict the eventual survivor, even in an asexual population. According to quasi-species theory, selection favours the cloud of genotypes, interconnected by mutation, whose average replication rate is highest. Here we confirm this prediction using digital organisms that self-replicate, mutate and evolve. Forty pairs of populations were derived from 40 different ancestors in identical selective environments, except that one of each pair experienced a 4-fold higher mutation rate. In 12 cases, the dominant genotype that evolved at the lower mutation rate achieved a replication rate >1.5-fold faster than its counterpart. We allowed each of these disparate pairs to compete across a range of mutation rates. In each case, as mutation rate was increased, the outcome of competition switched to favour the genotype with the lower replication rate. These genotypes, although they occupied lower fitness peaks, were located in flatter regions of the fitness surface and were therefore more robust with respect to mutations.

Mechanisms of diethylstilbestrol-induced calcium movement in MG63 human osteosarcoma cells

The effect of the estrogen diethylstilbestrol (DES) on cytosolic free Ca(2+) levels ([Ca(2+)](i)) in MG63 human osteoblasts was explored by using fura-2 as a Ca(2+) indicator. DES at concentrations between 5--20 microM induced an immediate increase in [Ca(2+)](i) in a concentration-dependent manner with an EC(50) of 10 microM. Removing extracellular Ca(2+) reduced the Ca(2+) signal by 70%. Pretreatment with 50 microM La(3+) or 10 microM of nifedipine, verapamil and diltiazem did not change 20 microM DES-induced [Ca(2+)](i) increases. Addition of 3 mM Ca(2+) increased [Ca(2+)](i) in cells pretreated with 20 microM DES in Ca(2+)-free medium. Pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor) to deplete the endoplasmic reticulum Ca(2+) store partly inhibited 20 microM DES-induced Ca(2+) release, but addition of carbonylcyanide m-chlorophenylhydrazone (CCCP; a mitochondrial uncoupler) and thapsigargin together abolished DES-induced Ca(2+) release. Conversely, pretreatment with 20 microM DES abrogated CCCP- and thapsigargin-induced Ca(2+) release. Inhibition of phospholipase C activity with 2 microM U73122 did not alter 20 microM DES-induced Ca2+ release. Another estrogen 17beta-estradiol also increased [Ca(2+)](i) in a concentration-dependent manner with an EC50 of 7 microM. Together, the data indicate that in human osteoblasts, DES increased [Ca(2+)](i) via causing Ca(2+) release from both mitochondria and the endoplasmic reticulum in a phospholipase C-independent manner, and by causing Ca(2+) influx.

Fendiline, an anti-anginal drug, increases intracellular Ca2+ in PC3 human prostate cancer cells

BACKGROUND

The effects of the anti-anginal drug fendiline on intracellular Ca2+ concentrations ([Ca2+]i) in human PC3 prostate cancer cells were examined.

METHODS

[Ca2+]i was measured using the fluorescent dye fura-2.

RESULTS

Fendiline (0.5-100 microM) increased [Ca2+]i in a concentration-dependent manner. Ca2+ removal partly inhibited the Ca2+ signals. In Ca2+-free medium, pretreatment with 100 microM fendiline inhibited most of the [Ca2+]i increase induced by 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor), and pretreatment with thapsigargin abolished the fendiline-induced [Ca2+]i increases. Adding 3 mM Ca2+ increased [Ca2+]i in cells pretreated with 0.5-200 microM fendiline in Ca2+-free medium. Pretreatment with 1 microM U73122 to block the formation of inositol-1.4.5-trisphosphate (IP3) did not alter fendiline-induced internal Ca2+ release.

CONCLUSIONS

The anti-anginal drug fendiline induced internal Ca2+ release and external Ca2+ entry. Because prolonged increases in [Ca2+]i may lead to cell injury and death, the long-term effect of fendiline on the function of prostate cancer cells should be investigated.

Effects of the antianginal drug fendiline on Ca2+ movement in hepatoma cells

This study investigated the effect of the anti-anginal drug, fendiline, on intracellular free Ca2+ levels ([Ca2+]i) in HA/ 22 human hepatoma cells by using fura-2 as a fluorescent Ca2+ dye. Fendiline (1-100 microM) increased [Ca2+]i with an EC50 of 25 microM. Removal of extracellular Ca2+ reduced the [Ca2+]i signals by 51 +/- 5%. Fendiline (10 microM)-induced Ca2+ release was abolished by pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor). Inhibition of phospholipase C with 2 microM 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122) did not alter 10 microM fendiline-induced Ca2+ release. Several other calmodulin antagonists, such as phenoxybenzamine (100-200 microM), trifluoperazine (5-50 microM), and fluphenazine-N-chloroethane (2-100 microM), had no effect on [Ca2+]i. Together, it was found that fendiline increased [Ca2+]i in human hepatoma cells by discharging Ca2+ from the endoplasmic reticulum in an inositol 1,4,5-trisphosphate-independent manner and by inducing Ca2+ entry. This effect of fendiline does not appear to be via antagonism of calmodulin.

[Studies on asymmetric synthesis of R-phenylethanolamine by whole cells of Arachnia sp. P163]

Effects of various factors on asymmetric synthesis of R-phenylaminoethanol from aminoacetophenone by the whole cells of Arachnia sp. P163 producing alcohol dehydrogenase for phenylethanol amine was investigated. It found that, although the reduction was inhibited by the substrate and the product, but it has the very high stereoselectivity. The reduction was normaly carried out with 2% glucose for reproduction of coenzyme in the reaction system without oxygen. The conversion yield and ee value of the product achieved 65% and 100%, respectively.

Clomiphene, an ovulation-inducing agent, causes [Ca2+]i increases in human osteoblast-like cells

The effect of clomiphene, an ovulation-inducing agent, on cytosolic free Ca2+ levels ([Ca2+]i) in MG63 human osteosarcoma cells was explored by using fura-2 as a Ca2+ indicator. Clomiphene at concentrations between 5-75 microM increased [Ca2+]i in a concentration-dependent manner with an EC50 of 50 microM. The [Ca2+]i signal consisted of an initial rise and a sustained phase. Ca2+ removal reduced the Ca2+ signal by 40+/-10%. The [Ca2+]i increase induced by 50 microM clomiphene was inhibited by 80+/-5% by 10 microM nifedipine, but was insensitive to 50 microM La3+ or 10 microM verapamil. In Ca2+-free medium, pretreatment with 50 microM brefeldin A (to disrupt the Golgi complex Ca2+ store), 1 microM thapsigargin (to inhibit the endoplasmic reticulum Ca2+ pump), and carbonylcyanide m-chlorophenylhydrazone (CCCP; to uncouple mitochondria) inhibited 51+/-3% of 50 microM clomiphene-induced Ca2+ release; conversely, pretreatment with 50 microM clomiphene abolished the [Ca2+]i increase induced by thapsigargin, CCCP, and brefeldin A. The Ca2+ release-induced by 50 pM clomiphene was unchanged by inhibition of phospholipase C with 2 microM 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122). Collectively, the results suggest that clomiphene increased [Ca2+]i, in osteoblast-like cells, by releasing intracellular Ca2+ in a phospholipase C-independent manner and by causing nifedipine-sensitive Ca2+ influx.

Effect of the neuroprotective agent riluzole on intracellular Ca2+ levels in IMR32 neuroblastoma cells

Riluzole is an effective neuroprotective drug. Its effect on intracellular free Ca2+ levels ([Ca2+]i) has not been explored. This study examined the effect of riluzole on [Ca2+]i in IMR32 neuroblastoma cells using fura-2 as a Ca2+ probe. Riluzole 0.1-1 mM increased [Ca2+]i in a concentration-dependent manner. Removal of extracellular Ca2+ inhibited the response by 52 +/- 5%. The [Ca2+]i increase induced by 0.2 mM riluzole was unaltered by 0.1 mM La3+ or 10 microM verapamil, but was inhibited by 51 +/- 4% by 10 microM nifedipine. In Ca2+-free medium, pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) reduced the 0.2 mM riluzole-induced Ca2+ release by 44 +/- 3%; this reduction was augmented to 66 +/- 5% by additionally depleting the Ca2+ stores in the Golgi complex with 50 microM brefeldin A. Inhibition of inositol 1,4,5-trisphosphate formation by 2 microM U73122, a phospholipase C inhibitor, did not affect Ca2+ release induced by 0.2 microM riluzole. It was concluded that the neuroprotective agent riluzole increased [Ca2+]i in IMR32 neuroblastoma cells concentration-dependently by releasing Ca2+ from multiple stores in an inositol 1,4,5-trisphosphate-independent manner and also by inducing nifedipine-sensitive Ca2+ influx.

Effect of diethylstilbestrol (DES) on intracellular Ca(2+) levels in renal tubular cells

The effect of the estrogen diethylstilbestrol (DES) on intracellular Ca(2+) concentrations ([Ca(2+)](i)) in Madin Darby canine kidney (MDCK) cells was investigated, using the fluorescent dye fura-2 as a Ca(2+) indicator. DES (10-50 microM) evoked [Ca(2+)](i) increases in a concentration-dependent manner. Extracellular Ca(2+) removal inhibited 45 +/- 5% of the Ca(2+) response. In Ca(2+)-free medium, pretreatment with 50 microM DES abolished the [Ca(2+)](i) increases induced by 2 microM carbonylcyanide m-chlorophenylhydrazone (CCCP; a mitochondrial uncoupler) and 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor); and pretreatment with CCCP and thapsigargin partly inhibited DES-induced [Ca(2+)](i) signals. Adding 3 mM Ca(2+) increased [Ca(2+)](i) in cells pretreated with 50 microM DES in Ca(2+)-free medium, suggesting that DES may induce capacitative Ca(2+) entry. 17beta-Estradiol (2-20 microM) increased [Ca(2+)](i), but 100 microM diethylstilbestrol dipropionate had no effect. Pretreatment with the phospholipase C inhibitor U73122 (1 microM) to abolish inositol 1,4,5-trisphosphate formation inhibited 30% of DES-induced Ca(2+) release. DES (20 microM) also increased [Ca(2+)](i) in human normal hepatocytes and osteosarcoma cells. Cumulatively, this study shows that DES induced rapid and sustained [Ca(2+)](i) increases by releasing intracellular Ca(2+) and triggering extracellular Ca(2+) entry in renal tubular cells.

[The experimental study of the delayed replantation after cryopreservation of mature tooth in dogs]

OBJECTIVE

To study the conditions of healing of mature tooth in dogs after long cryopreservation followed by replantation.

METHODS

The tooth was extracted after filling the root canals and then preserved for one week and three months respectively by Schwartz's method of cryopreservation of periodontal membrane. The specimens were took out eight weeks after replantation. It was demineralized in a 5% solution of formic acid,and then sectioned perpendicular to the long axes of tooth at a thickness of 5microm. The tooth were sectioned in step-serial sections at 500 microm intervals. The sections were stained with hematoxylin-eosin and followed by evaluation according to Andreasen.

RESULTS

The percentage of healing of periodontal membrane (PHPM) of the group of cryopreservation for one week was 64.53%. It was lower than the PHPM of the group of immediate replantation (85%), but the difference demonstrated no significance (P>0.05). The PHPM of the group of cryopreservation for three months was 50.3%. It was lower than the PHPM of the group of immediate replantation significantly (P<0.05).

CONCLUSION

The human's periodontal membrane may be cryopreserved longly and heals after the replantation of tooth as the human's tissues of corneas, skin, islets, et al may be done. The alveolar cavities to be newly made affect the healing of periodontal membrane in some degree.

Mechanisms of histamine-induced intracellular Ca 2+ release and extracellular Ca 2+ entry in MG63 human osteosarcoma cells 1 1Abbreviations: [Ca2+]i; Cytosolic free Ca2+ concentration; and IP3, inositol 1,4,5-trisphosphate

The effect of histamine on intracellular free Ca2+ levels ([Ca2+](i)) in MG63 human osteosarcoma cells was explored using fura-2 as a Ca2+ dye. Histamine increased ([Ca2+](i)) in a concentration-dependent fashion with an EC(50) value of 0.5 microM. Extracellular Ca2+ removal inhibited the ([Ca2+](i)) signals. Histamine failed to increase ([Ca2+](i)) in Ca2+-free medium after cells were pretreated with thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor). Addition of Ca2+ induced concentration-dependent ([Ca2+](i)) increases after preincubation with histamine in Ca2+-free medium. Histamine-induced intracellular Ca2+ release was abolished by inhibiting phospholipase C with 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122). The ([Ca2+](i)) increase induced by histamine in Ca2+ medium was abolished by cimetidine, but was not altered by pyrilamine, nifedipine, verapamil, and La(3+). Together, this study shows that histamine increased in ([Ca2+](i)) in osteosarcoma cells by stimulating H2 histamine receptors. The Ca2+ signal was caused by Ca2+ release from the endoplasmic reticulum in a phospholipase C-dependent manner. The Ca2+ release was accompanied by Ca(2+) influx.

Tamoxifen-induced Ca2+ mobilization in bladder female transitional carcinoma cells

This study examined the effect of tamoxifen, an anti-breast cancer drug, on Ca2+ handling in bladder female transitional cancer cells. Changes in cytosolic free Ca2+ levels were recorded by using the Ca2+-sensitive dye fura-2. In a dose-dependent manner, tamoxifen induced intracellular free Ca2+ concentrations ([Ca2+]i) increases between 5 and 20 microM with an EC50 of 10 microM. External Ca2+ removal reduced the response by 60+/-6%. Addition of 3 mM Ca2+ caused a [Ca2+]i increase after pretreatment with 10 microM tamoxifen in Ca2+-free medium. In Ca2+-free medium, pretreatment with 10 microM tamoxifen abolished the [Ca2+]i increase induced by 1 microM thapsigargin, an endoplasmic reticulum Ca2+ pump inhibitor. Conversely, pretreatment with 1 microM thapsigargin prevented tamoxifen from releasing more Ca2+. Inhibition of phospholipase C-dependent inositol 1,4,5-tris-phosphate formation with 2 microM U73122 did not alter 10 microM tamoxifen-induced Ca2+ release. The [Ca2+]i increase induced by 5 microM tamoxifen was not altered by 10 microM La3+, nifedipine, verapamil, and diltiazem. Collectively, it was found that tamoxifen increased [Ca2+]i in bladder cancer cells by releasing Ca2+ from the endoplasmic reticulum Ca2+ stores in a manner independent of phospholipase C activity, and by inducing Ca2+ entry from external medium.

Effect of fluoxetine on intracellular Ca2+ levels in bladder female transitional carcinoma (BFTC) cells

The effect of the antidepressant fluoxetine on Ca2+ signaling in cultured cells was largely unknown. The effect of various concentrations of fluoxetine on [Ca 2+] i in populations of bladder female transitional cancer (BFTC) cells was evaluated by using fura-2 as a Ca2+ probe. Fluoxetine increased [Ca 2+] i concentration dependently (20-100 microM) with an EC50 value of 30 microM. The response was inhibited by 50-60% on extracellular Ca2+ removal. In Ca2+ -free medium, pretreatment with 1 microM thapsigargin (an inhibitor of the endoplasmic reticulum Ca2+ pump) abolished 50 microM fluoxetine-induced Ca2+ release; whereas pretreatment with fluoxetine did not alter the thapsigargin-induced Ca2+ response. Addition of 3 mM Ca2+ increased [Ca 2+] i after pretreatment with 50 microM fluoxetine in Ca2+ -free medium, suggestive of fluoxetine-induced capacitative Ca2+ entry. Suppression of inositol 1,4,5-trisphosphate formation by 2 microM U73122 (a phospholipase C inhibitor) did not affect 50 microM fluoxetine-induced Ca2+ release. Collectively, this study shows that fluoxetine increased [Ca 2+] i in bladder cancer cells in a concentration-dependent fashion, by releasing Ca2+ from thapsigargin-sensitive Ca2+ stores in an IP3-independent manner, and by inducing Ca2+ influx from extracellular medium.

Fendiline-Induced Ca2+ movement in A10 smooth muscle cells

The effect of fendiline, an anti-anginal drug, on cytosolic free Ca2+ levels ([Ca2+]i) in A10 smooth muscle cells was explored by using fura-2 as a Ca2+ indicator. Fendiline at concentrations between 10-50 microM increased [Ca2+]i in a concentration-dependent manner with an EC50 of 20 microM. External Ca2+ removal reduced the Ca2+ signal by 75%. Addition of 3 mM Ca2+ increased [Ca2+]i in cells pretreated with fendiline in Ca2+-free medium. The 50 microM fendiline-induced [Ca2+]i increase in Ca2+-containing medium was inhibited by 10 microM of La3+, nifedipine, or verapamil. In Ca2+-free medium, pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) to deplete the endoplasmic reticulum Ca2+ store partly inhibited 50 microM fendiline-induced Ca2+ release; whereas pretreatment with 50 microM fendiline abolished 1 microM thapsigargin-induced Ca2+ release. Inhibition of phospholipase C activity with 2 microM U73122 did not alter 50 microM fendiline-induced Ca2+ release. Incubation with 50 microM fendiline for 10-30 min decreased cell viability by 10-20%. Together, the findings indicate that in smooth muscle cells fendiline induced [Ca2+]i increases. Fendiline acted by activating Ca2+ influx via L-type Ca2+ channels, and by releasing internal Ca2+ in a phospholipase C-independent manner. Prolonged exposure of cells to fendiline induced cell death.

Genetic deletion of COX-2 prevents increased renin expression in response to ACE inhibition

Cyclooxygenase-2 (COX-2) is expressed in macula densa (MD) and surrounding cortical thick ascending limb of the loop of Henle (cTALH) and is involved in regulation of renin production. We and others have previously found that selective COX-2 inhibitors can inhibit renal renin production (Cheng HF, Wang JL, Zhang MZ, Miyazaki Y, Ichikawa I, McKanna JA, and Harris RC. J Clin Invest 103: 953-961, 1999; Harding P, Sigmon DH, Alfie ME, Huang PL, Fishman MC, Beierwaltes WH, and Carretero OA. Hypertension 29: 297-302, 1997; Traynor TR, Smart A, Briggs JP, and Schnermann J. Am J Physiol Renal Physiol 277: F706-F710, 1999; Wang JL, Cheng HF, and Harris RC. Hypertension 34: 96-101, 1999). In the present studies, we utilized mice with genetic deletions of the COX-2 gene in order to investigate further the potential role of COX-2 in mediation of the renin-angiotensin system (RAS). Age-matched wild-type (+/+), heterozygotes (+/-), and homozygous null mice (-/-) were administered the angiotensin-converting enzyme inhibitor (ACEI), captopril, for 7 days. ACEI failed to significantly increase plasma renin activity, renal renin mRNA expression, and renal renin activity in (-/-) mice. ACEI increased the number of cells expressing immunoreactive renin in the (+/+) mice both by inducing more juxtaglomerular cells to express immunoreactive renin and by recruiting additional renin-expressing cells in the more proximal afferent arteriole. In contrast, there was minimal recruitment of renin-expressing cells in the more proximal afferent arteriole of the -/- mice. In summary, these results indicate that ACEI-mediated increases in renal renin production were defective in COX-2 knockout (K/O) mice and provide further indication that MD COX-2 is an important mediator of the renin-angiotensin system.

[Effects of combined transdermal acupoint electric stimulation and isoflurane anesthesia on isoflurane-induced hypotension and tissue oxygen metabolism in patients undergoing craniotomy]

OBJECTIVE

To observe the effects of combined transdermal acupoint electric stimulation and isoflurane anesthesia on isoflurane-induced hypotension and tissue oxygen metabolism in patients undergoing craniotomy.

METHODS

Forty-two patients with brain tumor of ASA physical status I or II and scheduled for elective surgery were randomly divided into two groups. The craniotomy was undergoing in Group A with isoflurane anesthesia, while in Group B, with combined transdermal acupoint electric stimulation (TAES) and isoflurane anesthesia. Isoflurane induced hypotension was performed in both groups by augmenting the concentration of isoflurane to lower the mean arterial pressure than before anesthesia for 30%-40% and maintain for 30-45 mins. The tissue oxygen metabolism, blood gas and arterial lactic acid level before, during and after hypotension were monitored by Swan-Ganz floating catheterization.

RESULTS

As compared with before hypotension, the pulmonary arterial and mixed with venous blood oxygen saturation lowered and oxygen supply lowered, and oxygen uptake increased significantly in both groups (P < 0.05), but the extent of changes in oxygen metabolic criteria in Group B were all lesser than those in Group A (P < 0.05).

CONCLUSION

Combined acupoint electric stimulation and general anesthesia could maintain the tissue oxygen supply and demand balance better in the isofluraneinduced hypotension process.

[Cochinchinenin--a new chalcone dimer from the Chinese dragon blood]

AIM

To study the active constituents of Dracaena cochinchinensis (Lour.) S.C. Chen. in the commercial dragon blood.

METHODS

Various column chromatographies with Sephadex L-20 gel, MCI gel and silica gel were employed for the isolation and purification. The structures of compounds were elucidated by spectral analysis.

RESULTS

Nine chalcones were isolated from the commercial dragon's blood which was made of D. cochinchinensis (Lour.) S.C. Chen.. By means of spectral data, they were identified as 1-[5-(2,4,4'-trihydroxydihydrochalconyl)]-1- (p-hydroxyphenyl)-3-(2-methoxy-4-hydroxy-phenyl)-propane (1), 2'-methoxysocotrin-5'-ol (2), socotrin-4'-ol (3), 2-methoxy-4, 4'-dihydroxydihydrochalcone (4), 2, 4, 4'-trihydroxy-dihydrochalcone (5), 2, 4, 4'-trihydroxy-6-methoxydihydrochalcone (6), 2', 4', 4-trihydroxychalcone (7), 2-methoxy-4, 4'-dihydroxychalcone (8) and 2'-methoxy-4', 4-dihydroxychalcone (9).

CONCLUSION

Compound 1 is a new chalcone dimer and named as cochinchinenin. Compounds 2-9 were isolated from D. cochinchinensis (Lour.) S.C. Chen. for the first time.

Primary peritoneal malignant mixed Müllerian tumors. A clinicopathologic, immunohistochemical, and genetic study

BACKGROUND

Primary peritoneal malignant mixed Müllerian tumors (MMMTs) are rarely reported in the literature.

METHODS

The clinical, pathologic, and immunohistochemical features of five cases of MMMT of female peritoneum were analyzed. The tumors were also investigated for expression of hormone receptors, specific BRCA-1 mutations, and clonality.

RESULTS

The patients' ages ranged from 33 to 67 years. They presented with abdominal pain or mass. One case of peritoneal MMMT was associated with a synchronous endometrial carcinoma whereas another case was detected 2 years after the diagnosis of a primary adenocarcinoma of the fallopian tube. One patient died 1 month after diagnosis whereas 2 patients died with disease within 1 year. Both carcinomatous and sarcomatous elements are present in all the tumors. Squamous differentiation was noted in two cases. Heterologous elements, including chondroid, rhabodomyoblastic, and osteoid differentiation were detected in all tumors. Immunohistochemical studies confirm the biphasic differentiation with variable demonstration of neural and smooth muscle differentiation. All five MMMTs were negative for estrogen and progestogen receptors although the related endometrial and tubal carcinomas were positive. Heteroduplex analysis used to screen for specific BRCA-1 mutations were negative in all five MMMTs. Clonality study of the two MMMTs found in association with endometrial carcinoma and tubal carcinoma was inconclusive.

CONCLUSIONS

Our study confirmed that primary peritoneal MMMTs were aggressive tumors with poor prognosis. The presence of synchronous or metachronous genital carcinomas suggests multifocal tumorigenesis from tissue of same embryologic origin. The lack of hormone receptor in these tumors indicates deviation from hormonal control. Specific BRCA-1 mutations found in ovarian carcinoma in Chinese patients could not be detected in our series.

Female sensitivity to diet and irradiation treatments underlies sex-mortality differentials in the Mediterranean fruit fly

Large-scale experiments on medflies that were subjected to sterilizing doses of ionizing radiation (plus intact controls) and maintained on either sugar-only or full, protein-enriched diets revealed that, whereas the mortality trajectories of both intact and irradiated male cohorts maintained on both diets are similar, the mortality patterns of females are highly variable. Mean mortality rates at 35 days in male cohorts ranged from 0.2 to 0.3 but in female cohorts ranged from 0.09 to 0.35, depending on treatment. The study reports three main influences: (a) qualitative differences exist in the sex-mortality response of medflies subjected to dietary manipulations and irradiation; (b) the female mortality response is linked to increased vulnerability due to the nutritional demands of reproduction; and (c) female sensitivity to environmental changes underlies the dynamics of the sex-mortality differential.

Characterization of histamine-induced increases in intracellular free Ca2+ concentrations in Chang liver cells

The effect of histamine on intracellular free Ca2+ levels ([Ca2+]i) in Chang liver cells were investigated by using fura-2 as a Ca2+ dye. Histamine (0.2-50 microM) increased [Ca2+]i in a concentration-dependent manner with an EC50 value of 0.8 microM. The [Ca2+]i response comprised an initial rise, a slow decay, and a sustained phase. Extracellular Ca2+ removal inhibited 50% of the maximum [Ca2+]i signal and abolished the sustained phase. After pretreatment with 5 microM histamine in Ca2+-free medium for 4 min, addition of 3 mM Ca2+ induced a [Ca2+]i increase with a magnitude 7-fold greater than control. In Ca2+-free medium, after treatment with 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor), 5 microM histamine failed to increase [Ca2+]i. Histamine (5 microM)-induced intracellular Ca2+ release was abolished

A multicentre study on eradication of Helicobacter pylori using four 1-week triple therapies in China

BACKGROUND

Short-term proton pump inhibitor-based triple therapies for the eradication of Helicobacter pylori are used widely. The eradication rates vary greatly from country to country and from region to region.

AIM

To assess the efficacy at eradicating H. pylori of 1-week regimens containing three medications: omeprazole (O) or colloidal bismuth subcitrate (B), furazolidone (F) or metronidazole (M), and amoxicillin (A) or clarithromycin (C).

METHODS

A multicentre study involving 20 hospitals in different regions of China. A total of 892 patients with H. pylori-positive non-ulcer dyspepsia or healed duodenal ulcer confirmed by endoscopy were recruited to receive, randomly, one of four regimens: OMC, OFC, OFA, and BFC, b.d. for 7 days. 13C-urea breath test was performed 4-8 weeks after completion of treatment.

RESULTS

The eradication rates with per protocol/intention-to-treat analyses were: OMC (n=217/219) 66%/65%; OFC (n=227/229) 69%/69%; OFA (n=223/225) 87%/86%; and BFC (n=214/219) 80%/78%. The eradication rate (per protocol analysis) in duodenal ulcer (79%) was higher than that in non-ulcer dyspepsia (73%, P=0.033). Patient compliance was good. The adverse events of the four regimens were mild, and mainly gastrointestinal.

CONCLUSIONS

The omeprazole, furazolidine and amoxicillin regimen achieves a high H. pylori eradication rate in different geographical regions of China.

Surface keratopathy after penetrating keratoplasty

PURPOSE

To determine the type and prevalence of epithelial abnormalities in the intermediate postoperative period after penetrating keratoplasty and to define the donor and recipient variables that influence the status of the graft epithelium.

DESIGN

Prospective cohort study.

METHODS

We prospectively followed the clinical course of 80 patients after penetrating keratoplasty. We monitored the status of the corneal epithelium for 3 months after surgery using slit-lamp biomicroscopy and fluorescein staining of the epithelium. Donor characteristics, recipient preoperative and postoperative variables, and postoperative medications were recorded. Epithelial abnormalities were analyzed against these variables by using univariate and combined statistical models to determine the impact of each variable on postoperative epithelial pathology. Main outcome measures included punctate keratopathy, macro-epithelial defects, hurricane keratopathy, rim defects, and filamentary keratopathy.

RESULTS

Sixty-three percent of all patient visits demonstrated punctate epithelial keratopathy (PEK). Hurricane keratopathy (51%) and filamentary keratopathy (14%) constituted the next most commonly observed abnormalities. Older recipient age and the use of topical antibiotics were associated with a higher prevalence of punctate epithelial keratopathy. The odds ratio (OR) for a 1-year increase in age is 1.0276 (95% CI, 1.1013-1.0442), and the OR for using topical antibiotics is 6.9028 (95% CI, 3.1506-15.1239). Use of topical ofloxacin and increased time after surgery were associated with lower prevalence of punctate keratopathy; ORs were 0.9806 (95% CI, 0.9736-0.9876) and 0.3662 (95% CI, 0.1688-0.7943), respectively. Decreased corneal sensation and the presence of anterior blepharitis preoperatively were associated with an increase in hurricane keratopathy; ORs were 8.8265 (CI, 2.3837-32.6835) and 3.2815 (CI, 1.7388-6.1931), respectively. Total storage time for the donor material was also associated with an increased prevalence of hurricane keratopathy (OR, 1.0316; CI, 1.0052-1.0220). Patients with rim defects and macro-epithelial defects were more likely to have antibiotic and topical lubrication prescribed. No specific variable was found to have a significant association with filamentary keratopathy, except possibly for death-to-preservation time, which had a P value of .0587.

CONCLUSIONS

Surface keratopathy is one of the most common complications of keratoplasty. Our study demonstrates that older age, preoperative lid disease, and decreased preoperative corneal sensation appear to increase the probability of clinically significant epithelial surface abnormalities after keratoplasty. Recognition of these risk factors in advance of surgery will alert the surgeon to the need for appropriate management.

Novel effects of 5,8,11-eicosatriynoic acid, a lipoxygenase inhibitor, on Ca2+ mobilization in Madin Darby canine kidney cells

The effect of 5,8,11-eicosatriynoic acid, a widely used lipoxygenase inhibitor, on Ca2+ fate in Madin Darby canine kidney cells was examined by using fura-2 as a Ca2+ probe. At concentrations between 2-100 microM 5,8,11-eicosatriynoic acid increased [Ca2+]i concentration-dependently with an EC50 of 20 microM . Extracellular Ca2+ removal decreased the Ca2+ signals, indicating that 5,8,11-eicosatriynoic acid triggered Ca2+ release and Ca2+ influx. 5,8,11 -Eicosatriynoic acid (30 microM) induced a [Ca2+]i increase in Ca2+-free medium after pretreatment with carbonylcyanide m-chlorophenylhydrazone (2 microM), a mitochondrial uncoupler, and thapsigargin (1 microM), an endoplasmic reticulum Ca2+ pump inhibitor for 20 min. Conversely, 5,8,11-eicosatriynoic acid pretreatment almost abolished the Ca2+ release induced by carbonylcyanide m-chlorophenylhydrazone and thapsigargin. These results suggest that 30 microM 5,8,11-eicosatriynoic acid released Ca2+ from the endoplasmic reticulum, mitochondria and other stores. Addition of 3 mM Ca2+ increased [Ca2+]i after preincubation with 2-50 microM 5,8,11-eicosatriynoic acid for 10 min. in Ca2+-free medium concentration-dependently. Pretreatment with 10 microM La3+ abolished 30 microM 5,8,11-eicosatriynoic acid -induced [Ca2+]i increases, but adding La3+ during the decay phase had no effect. 5,8,11-Eicosatriynoic acid-induced Ca2+ release was not altered by inhibiting phospholipase C with 2 microM 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122), but was decreased by 60% by 40 microM aristolochic acid. Several other lipoxygenase inhibitors such as baicalein (50 microM), 5.8.11.14-eicosatetraynoic acid (ETYA; 0.1-0.2 mM), caffeic acid (5-50 microM), esculetin (5-50 microM), alpha-pentyl-3-(2-quinolinylmethoxy)-benzenemethanol (REV-5901; 0.1-0.2 mM) and alpha-pentyl-4-(2-quinolinylmethoxy)-benzenemethanol (L-655238; 80-100 microM) had no effect on [Ca2+]i. Collectively, the data suggest that the lipoxygenase inhibitor 5,8,11-eicosatriynoic acid induced a [Ca2+]i increase in renal tubular cells concentration-dependently, by releasing intracellular Ca2+ from multiple stores in an inositol 1,4,5-trisphosphate-independent manner, and by inducing extracellular Ca2+ influx in a La3+-sensitive manner.

Histamine-Induced increases in intracellular free Ca2+ levels in hepatoma cells

The effect of histamine on intracellular free Ca2+ levels ([Ca2+]i) in HA22/VGH human hepatoma cells were evaluated using fura-2 as a fluorescent Ca2+ dye. Histamine (0.2-5 microM) increased [Ca2+]i in a concentration-dependent manner with an EC50 value of about 1 microM. The [Ca2+]i response comprised an initial rise, a slow decay, and a sustained phase. Extracellular Ca2+ removal inhibited 50% of the [Ca2+]i signal. In Ca2+-free medium, after cells were treated with 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor), 5 microM histamine failed to increase [Ca2+]i. After pretreatment with 5 microM histamine in Ca2+-free medium for 4 min, addition of 3 mM Ca2+ induced a [Ca2+]i increase of a magnitude 7-fold greater than control. Histamine (5 microM)-induced intracellular Ca2+ release was abolished by inhibiting phospholipase C with 2 microM 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122), and by 5 microM pyrilamine but was not altered by 50 microM cimetidine. Together, this study shows that histamine induced [Ca2+]i increases in human hepatoma cells by stimulating H1, but not H2, histamine receptors. The [Ca2+]i signal was caused by Ca2+ release from thapsigargin-sensitive endoplasmic reticulum in an inositol 1,4,5-trisphosphate-dependent manner, accompanied by Ca2+ entry.

Calorigenic actions of leptin are additive to, but not dependent on, those of thyroid hormones

We examined a possible mechanistic interaction between leptin and thyroid hormones in rats with hypothyroidism induced by thyroidectomy (TX) and propylthiouracil administration. In study 1, the TX rats were treated by vehicle (V, n = 9) or by recombinant murine leptin (L, 0.3 mg. kg(-1). day(-1), n = 9) or were pair-fed (PF, n = 9) against L. In study 2, the TX rats were all given 3, 3'5'-triiodo-L-thyronine (T(3)) replacement (T, 5 microg. kg(-1). day(-1)) to correct hypothyroidism. They were then subdivided into three groups, namely, vehicle (T+V, n = 9), leptin (T+L, n = 10), and pair-feeding (T+PF, n = 9), similar to study 1 except for T(3) (T). Reduced food consumption and weight gain in the TX rats were reversed by T(3) replacement. Leptin suppressed food intake in the TX rats regardless of T(3) replacement. O(2) consumption (VO(2)) and CO(2) production (VCO(2)) were reduced in TX rats (P < 0.05 vs. normal) but were normalized by either T(3) or leptin treatment. T+L additively increased VO(2) and VCO(2) (P < 0.05 vs. TX, T(3), and L). The respiratory exchange ratio was unaltered in TX rats, with and without T(3), but was significantly reduced by L or T+L treatments. These results indicate that the metabolic actions of leptin are not dependent on a normal thyroid status and that the effects of leptin and T(3) on oxidative metabolism are additive.

NPC-14686, a novel anti-inflammatory agent, increased intracellular Ca(2+) concentrations in MDCK renal tubular cells

The effect of NPC-14686 (Fmoc-L-homophenylalanine), a novel anti-inflammatory agent on intracellular free Ca(2+) concentrations ([Ca(2+)](i)) in Madin Darby canine kidney (MDCK) renal tubular cells, was investigated, using fura-2 as a Ca(2+) dye. At concentrations between 10 and 200 microM NPC-14686 increased [Ca(2+)](i) concentration dependently. The [Ca(2+)](i) signal comprised an initial rise and a sustained phase. Ca(2+) removal inhibited the Ca(2+) signals by 90%. In Ca(2+)-free medium, pretreatment with 100 microM NPC-14686 nearly abolished the [Ca(2+)](i) increase induced by 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor) and abolished the [Ca(2+)](i) increase induced by 2 microM carbonylcyanide m-chlorophenylhydrazone (CCCP) (a mitochondrial uncoupler). NPC-14686 (100 microM) induced a slight [Ca(2+)](i) increase after pretreatment with 2 microM CCCP and 1 microM thapsigargin. Addition of 3 mM Ca(2+) elicited a [Ca(2+)](i) increase in cells pretreated with 100 microM NPC-14686 in Ca(2+)-free medium. Inhibition of inositol-1,4,5-trisphosphate (IP(3)) production by suppressing phospholipase C with 2 microM U73122 did not alter NPC-14686-induced Ca(2+) release. Trypan blue exclusion revealed that incubation with 10 or 200 microM NPC-14686 for 1-30 min decreased cell viability by 10-20% concentration dependently. Collectively, the results demonstrate that, in MDCK tubular cells, NPC-14686 induced Ca(2+) release followed by Ca(2+) entry, with the latter playing a major role. NPC-14686 appears to release intracellular Ca(2+) in an IP(3)-uncoupled manner. NPC-14686 may be of mild cytotoxicity.

Synthesis of 60- and 72 kDa heat shock proteins in early porcine embryogenesis

Proteins of selected embryonic stages were metabolically labeled with [(35)S]-methionine and analyzed by two-dimensional SDS-polyacrylamide gel electrophoresis (2-D PAGE) to study protein expression from 4- to 8-cell to blastocyst stage of porcine embryos. Two proteins with molecular weights of 60 and 72kDa were de novo synthesized during the 4- to 8-cell stage were the earliest that were detected. They were identified as HSP60 and HSP72 according to their locations on 2-D autoradiography and the immunoblotting result of anti-HSP 60 and HSP 72 antibodies of 1-cell stage of porcine embryos. In protein translation in early pig embryogenesis the timing of their synthesis suggests that HSP60 and HSP72 play significant roles as chaperones.

Cryogen free automated gas chromatography for the measurement of ambient volatile organic compounds

An automated gas chromatographic system was constructed for measuring ambient volatile organic compounds (VOCs). Preconcentration of the VOCs was performed by using two separated sorbent traps of different combinations with each designated for either low or high boiling VOCs. Both traps and their associated valve systems were integrated as a complete system sharing a common sample inlet. Precise temperature controls for desorption relied on the use of a process controller with proportional-integral-derivative algorithm to throttle the current supply. No additional cryo-focusing stage prior to the column was needed owing to the flash heating capability for desorption. Other than the cryogen free preconcentration and focusing, the separation of VOCs of large volatility difference was also performed without cryogen. The system employed an Al2O3/KCl porous-layer open tubular column for separating C3-C7 compounds; and a DB-1 column for C6-C12. This automated GC system has been deployed in a Taiwan Environmental Protection Agency urban air quality monitoring station of Taiwan for continuous measuring C3-C7 ozone precursors. Excellent correlation between the car exhaust type of compounds measured by our GC system and carbon monoxide measured by a non-dispersive infrared spectrometer was observed, suggesting the automated GC system was robust and reliable.

Radiographic parameters for evaluating the neurological spaces in experimental thoracolumbar burst fractures

It is important to know the condition of neural spaces during the nonoperative treatment of thoracolumbar burst fractures. The goals of the current study were to identify the correlation between the degree of deformity of a fractured vertebra and the encroachment of neural spaces, and to determine how the encroachment and the deformity can be improved by the extension posture simulating the postural reduction. Experimental burst fractures were produced in L1 vertebrae of nine human thoracolumbar spine segments (T11-L3) with neural spaces lined with tiny steel balls. Lateral radiographs were taken in neutral and extended posture before and after the trauma. Anterior vertebral height, posterior vertebral height, vertebral height ratio, vertebral kyphotic angle, posterior vertebral body angle, and the cross diagonal angle were the geometric parameters used to describe the vertebral deformity. The canal diameter and superior and inferior intervertebral foramen areas were defined as the neural spaces. All parameters were measured on the scanned images of radiographs, as seen on the computer screen. Among the vertebral body parameters, the posterior vertebral height, posterior vertebral body angle, and cross diagonal angle showed significantly higher correlations with the canal encroachment. The extended posture did not improve the canal and intervertebral foramen encroachments. The kyphotic deformity (vertebral kyphotic angle and anterior vertebral height) was improved but the deformity of the vertebral posterior wall (posterior vertebral height and posterior vertebral body angle) was not improved because of the extended posture.

Dual action of palmitoyl trifluoromethyl ketone (PACOCF3) on Ca2+ signaling: activation of extracellular Ca2+ influx and alteration of ATP- and bradykinin-induced Ca2+ responses in Madin Darby canine kidney cells

The effect of the phospholipase A2 inhibitor palmitoyl trifluoromethyl ketone (PACOCF3) on Ca2+ signaling in Madin Darby canine kidney (MDCK) cells was examined using fura-2 as the fluorescent Ca2+ indicator. At a concentration of 20 microM, PACOCF3 did not change basal cytosolic free calcium concentrations ([Ca2+]i), but at concentrations of 50-250 microM PACOCF3 induced an increase in [Ca2+]i by activating extracellular Ca2+ entry which was partly suppressed by 50 microM La3+. The effect of PACOCF3 was abolished by removal of extracellular Ca2+. PACOCF3 (10 microM) enhanced both the peak value and the area under the curve of the [Ca2+]i increase induced by 10 microM ATP and 1 microM bradykinin by potentiating extracellular Ca2+ influx without affecting internal Ca2+ release. Several other phospholipase A2 inhibitors had no effect on basal [Ca2+]i or agonist-induced [Ca2+]i increases. Collectively, the results suggest that PACOCF3 alters Ca2+ signaling in renal tubular cells in a manner independent of phospholipase A2 inhibition.

Role of p38 in the regulation of renal cortical cyclooxygenase-2 expression by extracellular chloride

We have previously shown that in renal cortex, COX-2 expression is localized to macula densa and surrounding cortical thick ascending limb of Henle (cTALH). Dietary salt restriction increases local expression of COX-2, which mediates renin production and secretion. Given that decreased luminal chloride [Cl(-)] at the level of the macula densa increases renin production and secretion, we investigated the role of extracellular ion concentration on COX-2 expression. Quiescent rabbit cTALH cells were incubated in a physiological salt solution containing high or low levels of NaCl. Immunoreactive COX-2 expression increased significantly in the low NaCl solution. COX-2 expression also increased after administration of the Na(+)/K(+)/2Cl(-) cotransport inhibitor, bumetanide. Selective substitution of chloride led to increased COX-2 expression, whereas selective substitution of sodium had no effect. The p38 MAP kinase inhibitor PD169316 decreased low NaCl-induced COX-2 expression. Low-salt or low-chloride medium induced cultured cTALH to accumulate >/= 3-fold higher levels of pp38, the activated (phosphorylated) form of p38; low-salt medium also increased pJNK and pERK levels. Feeding rats a low-salt diet for 14 days induced a significant increase in renal cortical pp38 expression, predominantly in the macula densa and cTALH. These results suggest that reduced extracellular chloride leads to increased COX-2 expression, which may be mediated by activation of a p38-dependent signaling pathway.

Breast-cancer diagnosis with nipple fluid bFGF

Early diagnosis of breast cancer is the key to extending survival of breast-cancer patients. We found that the concentrations of nipple fluid bFGF (basic fibroblast growth factor) was significantly increased in breast-cancer patients compared with concentrations in controls (1717 ng/L [SD 706] vs 19 ng/L [19]; Student's t test p=0.027). Measurement of bFGF in nipple fluid could be a useful diagnostic tool for breast cancer, and deserves further study.

Anatomical subdivisions of the stomach of the Bactrian camel (Camelus bactrianus)

Twenty stomachs of Bactrian camels (Camelus bactrianus) were studied by gross dissection. Based on the configuration of the stomach and the structure of the mucous membrane, the stomach was divided into three ventricles that differ from the arrangement described for ox and sheep. The first and second ventricles of the proventriculus of camel form one stomach rather than two different stomachs. These ventricles of the proventriculus do not correspond to the rumen and reticulum of ox and sheep. The third ventricle appears to be the abomasum. One part of the abomasum has reticular mucosal folds that indicate it is not the reticulum. A second part of the abomasum has longitudinal mucosal folds suggesting it is not the omasum. Three glandular sac areas associated with the preventriculus and abomasum are also described.

[Genetic studies of blast resistance of indica variety Zhefu 802]

One indica variety, Zhefu 802, was studied for its inheritance of blast resistance by inoculation of two strains Ken54-04 and 95-t2. The B1F1 and F2 populations from cross of Zhefu 802(R) x Lijiangxintuanheigu (S) and related parents were inoculated by spray inoculation method with the two above mentioned strains to determine R:S ratio of segregating populations of this cross. The results indicated that Zhefu 802 has two dominant resistance genes to strain Ken 54-04. One of the two genes showed resistant reaction and the other is susceptible to strain 95-t2. The allelism test indicated that one gene in Zhefu 802, which showed resistant reaction to strain 95-t2, is allelic to Pi-i gene locus and non-allelic to loci of Pi-a, Pi-sh, Pi-k, Pi-z, Pi-ta, Pi-b, Pi-t. The other gene in this variety was also estimated to be different from all of the known genes. So it may be an unknown gene. But this point needs to be confirmed further.

The human myoepithelial cell displays a multifaceted anti-angiogenic phenotype

Human myoepithelial cells which surround ducts and acini of certain organs such as the breast form a natural border separating epithelial cells from stromal angiogenesis. Myoepithelial cell lines (HMS-1-6), derived from diverse benign myoepithelial tumors, all constitutively express high levels of active angiogenic inhibitors which include TIMP-1, thrombospondin-1 and soluble bFGF receptors but very low levels of angiogenic factors. These myoepithelial cell lines inhibit endothelial cell chemotaxis and proliferation. These myoepithelial cell lines sense hypoxia, respond to low O2 tension by increased HIF-1 alpha but with only a minimal increase in VEGF and iNOS steady state mRNA levels. Their corresponding xenografts (HMS-X-6X) grow very slowly compared to their non-myoepithelial carcinomatous counterparts and accumulate an abundant extracellular matrix devoid of angiogenesis but containing bound angiogenic inhibitors. These myoepithelial xenografts exhibit only minimal hypoxia but extensive necrosis in comparison to their non-myoepithelial xenograft counterparts. These former xenografts inhibit local and systemic tumor-induced angiogenesis and metastasis presumably from their matrix-bound and released circulating angiogenic inhibitors. These observations collectively support the hypothesis that the human myoepithelial cell (even when transformed) is a natural suppressor of angiogenesis. Oncogene (2000) 19, 3449 - 3459

Nitric oxide regulates renal cortical cyclooxygenase-2 expression

We have previously shown that cyclooxygenase-2 (COX-2) is localized to the cortical thick ascending limb of the loop of Henle (cTALH)/macula densa of the rat kidney, and expression increases in response to low-salt diet and/or angiotensin-converting enzyme (ACE) inhibition. Because of the localization of neuronal nitric oxide synthase (nNOS) to macula densa and surrounding cTALH, the present study investigated the role of nitric oxide (NO) in the regulation of COX-2 expression. For in vivo studies, rats were fed a normal diet, low-salt diet or low-salt diet combined with the ACE inhibitor captopril. In each group, one-half of them were treated with the nNOS inhibitors 7-nitroinidazole (7-NI) or S-methyl-thiocitrulline. Both of these NOS inhibitors inhibited increases in COX-2 mRNA and immunoreactive protein in response to low salt and low salt+captopril. For in vitro studies, COX-2 expression was studied in primary cultures of rabbit cTALH cells immunodisssected with Tamm-Horsfall antibody. Basal COX-2 immunoreactivity expression was stimulated by S-nitroso-N-acetyl-penicillamine (SNAP), an NO donor, and intracellular cGMP concentration. The cultured cells expressed immunoreactive nNOS, and 7-NI inhibited basal COX-2 immunoreactivity expression, which could be partially overcome by cGMP. In summary, these studies indicate that NO is a mediator of increased renal cortical COX-2 expression seen in volume depletion and suggest important interactions between the NO and COX-2 systems in the regulation of arteriolar tone and the renin-angiotensin system by the macula densa.

The role of bone graft force in stabilizing the multilevel anterior cervical spine plate system

STUDY DESIGN

The role of bone graft force in stabilizing an instrumented cervical spine was evaluated for one-level and three-level corpectomy models using in vitro experiments.

OBJECTIVES

To investigate the role of bone graft force in enhancing stability of anterior cervical plate, and to study effects of fatigue loading.

SUMMARY OF BACKGROUND DATA

The anterior cervical plate system is used widely in stabilizing the cervical spine after spinal corpectomy and grafting. Many factors such as applied screw torque, screw pullout force, plate strength, plate geometry, and type of bone graft have been studied. However, the role of bone graft in stabilizing the anterior plate system has not been explored.

METHODS

Two models (one-level and three-level) incorporating corpectomy, strut graft, and anterior plate were constructed from eight human spine specimens (C2-T1). The flexibility of an intact specimen and two constructs with graft forces of 0 N and 100 N was determined. A flexibility test, simulating physiologic loads, consisted of pure moments of flexion, extension, lateral bending, and axial torques up to 1 Nm. For each moment, range of motion and neutral zone were determined. The stability potential index was defined as the decrease in motion caused by instrumentation, as compared with intact motion. A larger stability potential index indicates a more stable spinal construct. Repeated measures analysis of variance was used to determine the significant changes.

RESULTS

In both models, bone graft force increased during extension, decreased during flexion, and showed minor changes during axial torsion and lateral bending. Higher bone graft force increased stability potential index-neutral zone and stability potential index-range of motion in the three-level model in all directions, but only in flexion-extension in the one-level model. Fatigue loading decreased bone graft force to a greater extent in the three-level model.

CONCLUSIONS

In the corpectomy-graft-anterior-plate model, graft force decreased in flexion and increased in extension. Higher graft force increased and fatigue decreased stability of the spinal construct in the three-level model.