[The RYR1 genotype of Chinese inbred pigs]

OBJECTIVE

Porcine stress syndrome (PSS) is one kind of molecular genetics defect diseases of pig which will cause malignant hyperthermia syndrome (MHS) and is the first index should be excluded in screening of a pig species for xenotransplantation. It was reported that mutation of pig rynodine receptor(RYR1) gene is the main reason for PSS. In this study, RYR1 genotypes of the Chinese Banna mini pig inbred line and inbreeding closed colony Wuzhishan pig were investigated with polymerase chain reaction-restriction endonuclease fragment length polymorphism (PCR-RFLP) technique.

METHODS

Antevenocaval whole blood samples were collected from 50 Banna mini-pig inbred-line(BMI), 15 inbreeding Wuzhishan pig (WZSP) and 25 Neijiang pigs (NJP) as negative control, the primer were designed and synthesized, PCR reaction was conducted following the sequence of 94 degrees C (1 min), 58 degrees C (1 min) and 72 degrees C (1 min) for 30 cycles. The PCR products were digested with restriction endonuclease HhaI and then electrophoresis check.

RESULTS

A 659 bp DNA fragment was amplified with these two primers, the HALNN sample fragment was cut into fragments as 493 bp and 166 bp individually after the digestion, indicates no point mutation at site 1,843 in RYR1 gene in all tested BMI pig and WZSP. Namely, the RYR1 genotype of 50 cases of BMI and 15 cases of WZSP were HALNN, therefore their phenotype is PSS negative.

CONCLUSION

It indicates that the genotype of Banna mini pig inbred line and inbreeding Wuzhishan pig are HALNN therefore PSS absolutely negative, the group penetrance is 0. This is consistent with experimental observation. It suggests that Banna mini pig inbred line and inbreeding Wuzhishan pig may be the alternative donor for xenotransplantation.

Simultaneous chiral separation of triadimefon and triadimenol by sulfated beta-cyclodextrin-mediated capillary electrophoresis

Enantiomeric separation of two triazole fungicides, triadimefon and triadimenol, was investigated in sulfated beta-cyclodextrin (sulfated beta-CD)-mediated capillary electrophoresis (CE) systems. It was found that, at pH 2-4, sulfated beta-CD exhibited strong chiral recognition towards both triadimefon and triadimenol. The enantiorecognition was believed to result from the multiple interactions between sulfated beta-CD and the analytes, which included inclusion effect, electrostatic interaction, and hydrogen bonding. Under optimal conditions (phosphate buffer with 2% sulfated beta-CD, pH 2.5), simultaneous resolution of all chiral isomers of triadimefon and triadimenol was achieved in less than half an hour. In conjunction with solvent extraction and subsequent enrichment by solid-phase extraction (SPE), this new enantioseparation method was applied successfully in the study of stereoselectivity associated with the biotransformation of triadimefon to triadimenol by soil microorganisms. The present methodology was superior to the commonly adopted chiral gas chromatography (GC) approach in that a very mild procedure was involved from sample extraction to the ultimate chiral separation. Thus, the disturbance of the enantiomeric distribution patterns of the original soil samples by heat stress was an unlikely scenario. Furthermore, it was discovered that, owing to the unique selectivity of the present separation strategy, there was virtually no interference from the soil matrix, which led to improvements in both sensitivity and selectivity in real sample determination.

Separation of polymerase chain reaction amplified bird genes by capillary electrophoresis

Female birds possess one Z and one W chromosome, whereas male birds possess two identical Z chromosomes. Thus, the presence of a W genetic marker is diagnostic of the female sex. Capillary electrophoresis with buffer containing an entangled solution of hydroxyethylcellulose was used to separate the polymerase chain reaction (PCR) amplified bird sexing genes CHD-Z and CHD-W. The relative standard deviations (RSD) were less than 0.6% for the male genes and less than 0.4% for the female genes for six runs and detection limits of 0.1 ng/microL were obtained with laser-induced fluorescence (LIF) detection. Using a DNA ladder and theoretical models for DNA separation in sieving media, the sizes of the two bird genes were determined.

Prospective confirmation of low arrest rates among intoxicated drivers in motor vehicle crashes

OBJECTIVE

Several states have legally sanctioned or mandated physician reporting of drivers who were driving while intoxicated (DWI). Valid prospective evidence demonstrating extremely poor performance of the criminal justice system seems ethically and scientifically essential if overriding public health considerations are to abrogate the fundamental principles of patient-physician confidentiality. No such evidence is available. The authors reasoned that poor performance of the judicial system would be most evident if drivers who were DWI were not arrested under conditions selected to optimize legal intervention. The authors therefore wished to estimate the unbiased proportion of DWI drivers brought to an emergency department (ED) under these optimized conditions who escape detection by law enforcement officials.

METHODS

Prospective, consecutive cohort of drivers transported to an urban ED following a motor vehicle crash (MVC). Conditions selected to optimize legal intervention included: police at scene; inebriation of driver clinically evident to out-of-hospital personnel; and confirmatory blood ethanol level > or =100 mg/dL (> or =22 mmol/L). Main outcome measure was arrest for DWI.

RESULTS

Of 294 drivers in MVCs, 270 had ethanol levels, of whom 18 met criteria for optimum likelihood of legal intervention. Of these, 22% were arrested for DWI (95% CI = 6% to 48%). Adjustment for missing data, under assumptions designed to maximize arrest frequency for DWI, did not materially alter these findings. No patients were lost to follow-up.

CONCLUSION

These findings prospectively confirm that, even under conditions selected to optimize detection by law enforcement officials, only about one of every five drivers who were DWI and were brought to an ED following an MVC-and almost certainly no more than a minority-comes to the attention of the criminal justice system.

Coupling of solvent semimicroextraction with capillary electrophoresis using ethyl acetate as sample matrix

This paper reports a strategy to couple liquid-liquid semimicroextraction (LLsME) with capillary electrophoresis (CE) based on a newly introduced on-column decomposable sample matrix, ethyl acetate (EA). LLsME was performed in volumetric flasks of 100 mL. Samples containing an aqueous phase were first saturated with EA. Then, an extra 500 microL of EA was added to extract the samples. Sample injection in CE could be made in hydrodynamic mode by dipping the injection end of the capillary into the organic (EA) phase in the volumetric flasks. As a demonstration, alkylphenones in water samples were extracted by LLsME into EA and subjected to separation by micellar electrokinetic chromatography (MEKC). Alkylphenones of C8-C12 with concentrations of about 10 ppb can be concentrated and detected after extraction; extraction efficiencies range from 72- to 334-fold. Linearity of extraction was determined and the effect on reproducibility by spiking an internal standard was studied. The method developed is time-saving and requires no further special experimental device other than a basic CE setup. Therefore, it would be readily acceptable for routine analysis, especially in analytical laboratories dealing with environmental samples.

High-speed chiral separations on microchip electrophoresis devices

High-speed electrophoretic chiral separations have been successfully performed in a microfabricated device by employing cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC). Utilizing short separation channels and relatively high field strengths in combination with small volume-defined injection plugs, and operating in counter-electroosmotic flow conditions, fast and efficient separations of fluorescein insothiocyanate (FITC)-labeled amino acid enantiomers were obtained. Analysis time ranged from 75 s for the most basic amino acids to 160 s for the most acidic ones with associated efficiencies from 7000 up to 28 000 effective plates (100 000 to 395 000 plates/m). Buffer parameters were varied in order to study the effect on chiral resolution. A buffer system consisting of 100 mM borate (pH 9.4), 30 mM of SDS, and 10 mM gamma-CD as chiral selector provided adequate resolution of the majority of FITC-amino acid enantiomers tested.

HCPTPA, a protein tyrosine phosphatase that regulates vascular endothelial growth factor receptor-mediated signal transduction and biological activity

Angiogenesis is a tightly controlled process in which signaling by the receptors for vascular endothelial growth factor (VEGF) plays a key role. In order to define signaling pathways downstream of VEGF receptors (VEGFR), the kinase domain of VEGFR2 (Flk-1) was used as a bait to screen a human fetal heart library in the yeast two-hybrid system. One of the signaling molecules identified in this effort was HCPTPA, a low molecular weight, cytoplasmic protein tyrosine phosphatase. Although HCPTPA possesses no identifiable phosphotyrosine binding domains (i.e. SH2 or phosphotyrosine binding domains), it bound specifically to active, autophosphorylated VEGFR2 but not to a mutated, kinase-inactive VEGFR2. Recombinant VEGFR2 and endogenous VEGFR2 were substrates for recombinant HCPTPA, and HCPTPA was co-expressed with VEGFR2 in endothelial cell lines, suggesting that HCPTPA may be a negative regulator of VEGFR2 signal transduction. To pursue this possibility, an adenovirus directing the expression of HCPTPA was constructed. When used to infect cultured endothelial cells, this adenovirus directed high level expression of HCPTPA that resulted in impairment of VEGF-mediated VEGFR2 autophosphorylation and mitogen-activated protein kinase activation. Adenovirus-mediated overexpression of HCPTPA also inhibited VEGF-induced cellular responses (endothelial cell migration and proliferation) and inhibited angiogenesis in the rat aortic ring assay. Taken together, these findings indicate that HCPTPA may be an important regulator of VEGF-mediated signaling and biological activity. Potential interactions with other signaling pathways and possible therapeutic implications are discussed.

Screening of carbohydrates in urine by capillary electrophoresis

Carbohydrate analysis of urine is clinically important in assisting diagnosis of disorders of carbohydrate metabolism and understanding its pathologic significance. Paper chromatography and thin-layer chromatography are the techniques that are often employed for the determination of urinary carbohydrates. An aim of our experiments was to investigate the utility of capillary electrophoresis to develop a fast screening procedure of urinary carbohydrates. Simultaneous resolution of eight carbohydrates involving maltose, lactose, D-mannose, D-glucose, D-ribose, D-xylose, L-arabinose and D-galactose as markers was obtained with 130 mM borate (pH 10.2). Ethanol/water (80/20 v/v) and acetonitrile proved to be efficient reagents for urine sample clean-up which produced symmetrical peaks. The urine sample from a normal subject was determined to contain lactose, glucose, xylose and arabinose that fall within normal ranges of these carbohydrates in urine. The investigations made in this study may be potentially useful in carbohydrate screening, especially in neonatal urine screening.

Self-assembled monolayer-based piezoelectric crystal immunosensor for the quantification of total human immunoglobulin E

This work presents a piezoelectric (Pz) immunosensor for the quantification of total human IgE in serum samples. The anti-human IgE is deposited on the surface of the 10 M Hz AT-cut gold coated crystal resonator by self-assembled technique, and serves as a receptor layer. The highly ordered self-assembled monolayers (SAMs) ensure well-controlled surface structure and offer many advantages to the performance of the sensor. The fabricated Pz sensor can quantitatively detect human serum IgE in the range of 5-300 IU/ml with high precision (CV < 8%). A total of 28 patient serum samples are detected by the Pz sensor, and the results agree well with those given by two commercially provided test kits (Total IgE FAST Test, Pharmacia-CAP). The correlation coefficients are 0.94 between FAST and Pz sensor, and 0.90 between CAP and Pz sensor, respectively. After regeneration with urea and glycine buffer the coated crystal can be reused five times without appreciable loss of activity. Compared with conventional cross-linking methods, nonspecific binding caused by the SAM binding method is three to five times less.

Prevalence study and molecular characterization of alpha-thalassemia in Filipinos

In order to determine the prevalence and molecular basis of alpha-thalassemia (thal) among Filipinos, a total of 2954 Filipinos in Taiwan were enrolled in this study. A complete blood count was done for every subject. Those with microcytosis (MCV less than 82.5 fl) were studied with hemoglobin (Hb) high-performance liquid chromatography to determine the levels of Hb A2 and Hb F, and with an enzyme immunoassay to determine plasma ferritin levels. Those who had microcytosis and normal or low levels of Hb A2 and Hb F were further studied with molecular methods for alpha-globin gene mutations. We used Southern blot hybridization and/or the polymerase chain reaction to detect Southeast Asian deletion, Filipino deletion, rightward and leftward single alpha-globin gene deletions, and Hb Constant Spring and Hb Quong Sze. Specific amplification and direct DNA sequencing of the alpha2- and alpha1-globin genes were carried out in apparent alpha-thal carriers without any of the above-mentioned mutations. Our results showed that in Filipinos the prevalence of alpha-thal 1 was 5% (147 carriers) and that of alpha-thal 2 was 1.7% (49 carriers); two had Hb H disease. Among the alpha-thal 1 carriers, 89 had the Southeast Asian deletion and 58 had the Filipino deletion. Among the alpha-thal 2 carriers, 48 had a rightward deletion and one had a leftward deletion. None had Hb Constant Spring or Hb Quong Sze. Specific amplification and DNA sequencing in five apparent alpha-thal carriers did not reveal mutations in the 2-kb region spanning the alpha2- and alpha1-globin genes. The molecular defects of alpha-thal in Filipinos were different from those in the neighboring ethnic groups. Elucidation of the alpha-thal mutations in Filipinos is useful in the genetic counseling and prenatal diagnosis of this common disease.

Indirect laser-induced fluorescence detection of valproic acid in human serum by capillary electrophoresis

A capillary electrophoresis (CE) method with indirect laser-induced fluorescence detection for the analysis of valproic acid in human serum has been explored. The buffer system was optimized with 2.5 mM borate-phosphate at pH 8.4; fluorescein sodium was used to generate background signal at a concentration of 6 microM. Hexanoic acid was selected as internal standard. Serum sample was deproteinized by acetonitrile. Analysis was performed by direct injection of the supernatant. CE separation was carried out at 30 kV and the total analysis time was less than 15 min, including sample treatment and electrophoresis time. No interference from other common anticonvulsant drugs occurred under the experimental conditions used. The interference of human serum matrix was reduced by using a high ratio of acetonitrile to serum (minimum 5:1) for deproteinization. Interference of ionic components in serum could occur, depending on the sample source. The linear range of concentrations for standard drug was between 4.5-144.0 microg/mL (r = 0.9947). The limit of detection was 0.9 microg/mL at S/N > or = 3; the limit of quantitation at S/N > or = 20 was 3 microg/mL. The recoveries of valproic acid spiked into serum were 69.2% and 60.2% for concentration levels of 90 and 54 microg/mL, respectively. This CE method was shown to be successful in the analysis of valproic acid in standard solutions. However, interference from the matrix was observed in the analysis of this compound in serum samples. Additional work should be done to develop a highly selective sample preparation technique.

Ion-pair solid-phase extraction of biogenic amines before micellar electrokinetic chromatography with laser-induced fluorescence detection of their fluorescein thiocarbamyl derivatives

Extraction conditions by ion-pair solid-phase extraction of biogenic amines from soy sauce samples were studied. The type of surfactant used as ion-pair reagent, the mode of extraction and the pH were factors studied to enhance the extraction efficiency. High recoveries were obtained using dodecylbenzenesulfonic acid as ion-pair reagent. Octanesulfonate and decanesulfonate did not provide satisfactory recoveries. A dynamic ion-pair solid-phase extraction method was also tested for comparison. The extracted amines were derivatized with fluorescein isothiocyanate, separated by micellar electrokinetic chromatography and detected by laser-induced fluorescence (MEKC-LIF). Because of sample clean-up after extraction and the very high number of theoretical plates obtained with the MEKC-LIF method, identification and quantification of biogenic amines in soy sauce samples could be accomplished. Biogenic amines in soy sauce samples could be separated and quantified with detection limits of the order of 0.1 microg/mL, depending on the sample source.

Three toxins with phospholipase activity isolated from the yellow-legged hornet (Vespa verutina) venom

The yellow-legged hornet, Vespa verutina, is widely distributed in both the mountain area and the suburbs of Taiwan and possesses highly toxic venom (LD50=0.02 microl/g mouse). By gel filtration on Fractogel (TSK HW 50f) followed by cation-exchange chromatography on Mono S column, three toxins designated as verutoxin 1, 2a and 2b (VT-1, VT-2a and VT-2b) were isolated from the venom. The toxin VT-1 had a molecular mass of 34,982 Da and an LD50 value of 3.61 microg/g mouse. Toxin VT-2a and 2b were more basic and more toxic than VT-1. VT-2a and 2b were isotoxins with molecular masses differing in only 14 Da (33,360 and 33,374 Da, respectively) and had a similar toxicity in mice (LD50=0.87 microg/g mouse). All three toxins were capable of catalyzing the hydrolysis of emulsified phospholipids and lysophosphatide, but not sphingomyelin. Analysis of the hydrolyzed products (fatty acid and lyso-compound) by a liquid chromatography/mass spectrometer revealed that the toxins liberates fatty acid mainly from the 1-position of the synthetic phospholipid. This result indicates that verutoxins possess phospholipase A1 activity. Toxin VT-1 showed higher phospholipase activity than VT-2a and 2b. However, the latter toxins exhibited much higher direct hemolytic activity toward the mouse red blood cells. Vespid phospholipases are known as one of the three major venom allergens in many species of wasps. Our studies indicate that vespid phospholipases A1, in addition to acting as allergens, possess direct toxic actions that may also cause death in animals. Toxin VT-2a and 2b which possess potent hemolytic activity and high lethality in mice may act as the lethal factor of V. verutina venom.

Enantiomeric separation of amino acids derivatized with fluoresceine isothiocyanate isomer I by micellar electrokinetic chromatography using beta- and gamma-cyclodextrins as chiral selectors

Enantiomeric separation of 21 amino acids derivatized with fluoresceine isothiocyanate isomer I (FITC) has been studied by micellar electrokinetic chromatography using beta- and gamma-cyclodextrin (CD) as chiral selectors. Chiral resolution of 21 FITC derivatives of amino acids was achieved with both beta- and gamma-CD in 100 mM borate buffer (pH 9.5) containing 30 mM sodium dodecyl sulfate (SDS). The effects of CD concentration, SDS concentration and organic modifiers' concentration as well as capillary length were investigated. Chiral recognition capability of beta- and gamma-CD was compared. Gamma-CD was found to be a better chiral selector than beta-CD in terms of chiral resolution capability for FITC-amino acids.

A novel MYB-related gene from Arabidopsis thaliana expressed in developing anthers

A novel MYB-like gene (AtMYB103) was isolated from a genomic library of Arabidopsis. Plants transgenic for chimeric AtMYB103 promoter/GUS genes expressed the enzyme in early anthers. In situ hybridization of flower sections showed a high level of AtMYB103 mRNA in the tapetum and middle layer of developing anthers.

Chiral resolution of atropine, homatropine and eight synthetic tropinyl and piperidinyl esters by capillary zone electrophoresis with cyclodextrin additives

Chiral resolution of atropine, homatropine and eight synthetic tropinyl and piperidinyl esters were studied by capillary zone electrophoresis with cyclodextrin additives. Atropine and eight synthetic derivatives were successfully resolved by heptakis-(2,3,6-tri-O-methyl)-beta-cyclodextrin (TM-beta-CD) at concentrations ranging from 10 to 40 mM. Homatropine was baseline resolved by 10 mM beta-cyclodextrin and hydroxypropyl-beta-cyclodextrin (HP-beta-CD), respectively. The developed method was employed for the determination of atropine enantiomers in human serum.

Sentinel surveillance for enterovirus 71, Taiwan, 1998

Outbreaks of enterovirus 71 have been reported around the world since 1969. The most recent outbreak occurred in Taiwan during April-July 1998. This hand, foot, and mouth disease epidemic was detected by a sentinel surveillance system in April at the beginning of the outbreak, and the public was alerted.

Microchannel electrophoretic separation of biogenic amines by micellar electrokinetic chromatography

Fast, efficient separation of most common biogenic amines was successfully performed on a glass microchip capillary electrophoresis device. The amines putrescine, histamine, tyramine, cadaverine, phenethylamine, tryptamine, spermidine and spermine were derivatized prior to fluorescence detection with fluorescein isothiocyanate. Separation was carried out using a channel length of 28 mm, a cross section of 50 x 8 microm, and a field strength of 600 V/cm. After optimization of buffer electrolyte conditions (120 mM boric acid, pH 9.4, modified with 40 mM SDS), fluorescein thiocarbamyl amine derivatives were successfully resolved. Analysis time was as short as 75 s. Determination of the biogenic amines was achieved in soy sauce samples.

The correlation between skin electrical conductance and the score of qi vacuity

In traditional Chinese medicine, the syndrome of qi vacuity means that the patient's body has a low level of energy to react to stress. Recently, we used a score, the QV score, by scaling the severity of symptoms and signs of qi vacuity in patients with tiredness. The aim of this study was to investigate the relationship between QV score and skin electrical conductance in patients with tiredness. One hundred and forty-three healthy controls and 103 patients with tiredness were involved. Each subject received a weak electrical stimulation with constant voltage (1.75 volt), and conductance was measured between two different limbs. The mean value of skin conductance among four limbs was calculated and expressed by a special unit, namely Chin. The correlation between the skin conductance and QV score was analyzed by a linear regression analysis. The results showed that skin electrical conductance of healthy controls was negatively correlated with age (r-coefficient = -0.51, P = 0.000). The skin conductance of patients with tiredness was significantly lower than that of healthy controls with matching age (P = 0.000 by Student's t-test). Moreover, there was a positive correlation between the decrease of skin conductance and the QV score in patients with tiredness (r-coefficient = +0.68, P = 0.000). These results suggest that a decrease in skin electrical conductance may be closely related to the severity of qi vacuity. The skin conductance test is a simple, reliable, and quantitative method for detection of syndrome of qi vacuity.

Apoptosis is induced in aging SV40 T antigen-transformed human fibroblasts through p53- and p21CIP1/WAF1-independent pathways

When comparing SV40 T antigen-transformed human fibroblasts of a younger generation (24 population doubling) and aging stage (58 population doubling), we found that detachment of cells from the culture surface occurred more frequently in aging cells. DNA fragmentation and chromatin condensation which are typical findings of apoptosis occurred more frequently in aging cells as compared to cells of a younger generation. There is no increase in the p53 level or decrease in the SV40 T antigen level in aging cells as compared to cells of a younger generation. Retinoic acid treatment which can effectively suppress p21 gene expression did not prevent apoptosis. These findings indicate that apoptosis that occurs due to aging-transformed human fibroblasts is mediated through p53- and p21-independent pathways.

Nonaqueous capillary zone electrophoresis for separation of free fatty acids with indirect fluorescence detection

The feasibility of combining nonaqueous capillary zone electrophoresis with indirect fluorescence detection was studied for the efficient separation and sensitive detection of ionizable hydrophobic substances which do not possess practically suitable detection properties. Medium- and long-chain free fatty acids, C6-C24, were selected as test compounds. The results showed that such a wide range of medium- and long-chain free fatty acids could be separated between any two consecutive homologs in one run and be detected at a level of about 0.01-0.02 mM in highly basic methanol/acetonitrile media containing fluorescein as coion of background electrolyte for indirect fluorescence detection.

Dual UV-absorbing background electrolytes for simultaneous separation and detection of small cations and anions by capillary zone electrophoresis

The simultaneous separation and detection of small cations and anions by capillary zone electrophoresis (CZE) with indirect ultraviolet (UV) detection was successfully demonstrated in a background electrolyte (BGE) containing two UV-absorbing components. Benzylamine, imidazole, benzenesulfonic acid, sulfosalicylic acid, and pyromellitic acid were tested as the components of the BGE. The success of the simultaneous separation of the cations and anions is dependent upon the proper selection of the electrolyte components and control of the migration of the ions towards the detector. High pH is beneficial to the detection of anionic analytes but not to the separation of cationic analytes because of large electroosmotic flow produced under this condition. The upper pH limit of the working pH range is confined by the pKa value of the cationic component of the BGE. The influence of pH and total electrolyte concentration on the electroosmatic flow (EOF) counteracted each other. This counteraction effect imposes an upper limit on the change of total electrolyte concentration at certain pH. It was found that the EOF should be larger by at least 10 x 10(-5) cm2V(-1)s(-1) than the electrophoretic mobilities of the anions so that the anions could be detected on the cathodic side within reasonable times and with good peak shapes. In the imidazole-sulfosalicylic acid BGE, the detection limits (signal to noise, S/N = 3) for the cations and anions ranged from 100 to 900 ppb. In the benzylamine-pyromellitic acid BGE, K+, Na+, Li+, CH3 COO-, HPO4(2-), F-, ClO3-, ClO4-, NO3-, NO2-, Cl- and SO4(2-) were separated within twelve minutes. The strategies for selection of the electrolyte components of the binary BGE were also discussed.

Comparative histopathology of hepatic allografts and xenografts in the nonhuman primate

Liver transplantation was performed in the following groups: Group 1, baboon-to-baboon allografting (n=8) (control group); Group 2, ABO-compatible vervet monkey-to-baboon xenografting (n=8); Group 3, ABO-incompatible vervet monkey-to-baboon xenografting (n=6); Group 4, pig-to-baboon xenografting (n=2); and Group 5, pig-to-rhesus monkey xenografting (n=6). Immunosuppressive therapy (cyclosporine, cyclophosphamide, and methylprednisolone) was begun 2-7 days before liver transplantation (LTx) and continued indefinitely after LTx. The liver grafts were biopsied pre-LTx and subsequently post-LTx at approximately 1 hr, 2-3 hr, 7-10 days, 20-30 days, 60 days, 120 days, and at euthanasia or spontaneous death. There were 19 successful LTxs with grafts functioning from one hour to 123 days. No pig liver (Groups 4 and 5) survived more than 5.5 hr, as there was an immediate severe vascular response after reperfusion, typical of hyperacute rejection (congestion and hemorrhage). Vascular rejection was not seen in allografts (Group 1), but early mild-to-moderate congestion and neutrophil infiltration were present in concordant xenografts (Groups 2 and 3), which were associated with moderate deposition of immunoglobulin, C3, and fibrinogen. Lymphoid cell infiltration, bile duct damage, and portal vein endothelialitis in the portal zones occurred later in both allografts (Group 1) and concordant xenografts (Groups 2 and 3), developing earlier in the presence of ABO-incompatibility (Group 3). In concordant xenografts it was usually followed by fibrosis.

Rapid estimation of octanol-water partition coefficients of pesticides by micellar electrokinetic chromatography

Micellar electrokinetic chromatography (MEKC) was evaluated as a new technique for the rapid estimation of octanol-water partition coefficient (logKow). Retention measurements for more than 40 reference pesticides with varied structural characteristics and hydrophobicity were carried out in two MEKC systems, based on sodium dodecyl sulfate (SDS) and sodium cholate (SC), respectively. To enable an accurate determination of capacity factors in the SC-MEKC system, cypermethrin (a synthetic pyrethroid insecticide) was utilized instead of Sudan III as the SC micelle tracer, since a few highly hydrophobic pesticides were found to elute after Sudan III. The linear correlation between logarithmic capacity factor (logk') and logKow in the two systems was examined. It was found that, under the typical buffer condition (10 mM sodium phosphate with 60 mM surfactant, pH 7.0), the SDS-MEKC system provided a somewhat wider dynamic range for hydrophobicity (logKow from -1.0 to 4.5). However, the correlation of logk' with logKow was not very high when all the reference pesticides were included in one single calibration set. For the SC-MEKC system, the dynamic range for logKow was in the range of 1.0-5.5, and a good linear correlation existed between logk' and logKow, even when all reference pesticides were incorporated into a single calibration group. By comparing the regression line of the reference pesticides with that of a group of simple aromatic derivatives, it was discovered that molecular size and functionality posed a less significant effect on the measurement of logKow in the SC-MEKC system than in the SDS-MEKC system. Thus, SC-MEKC shall be the system of choice for the estimation of logKow. The typical error on logKow determination using the current MEKC technique was within 0.5 units, suggesting that MEKC can be a valuable complement to reversed phase high performance liquid chromatography (RP-HPLC) for the indirect determination of logKow. Besides maintaining all the advantages of the HPLC approach, the MEKC technique showed some unique benefits, such as better inter-column reproducibility, higher throughput, and less handling of toxic pesticides and solvents.