Photodynamic agents, due to their selective uptake by tumor cells and photon-dependent selective activation, have immense implications for cancer treatment. The present study provided direct evidence that the photon activation of chloro-aluminum phthalocyanine sulphonate (AlPcS4) in the presence of extracellular Ca2+ caused a rapid increase followed by a sustained increase in intracellular concentration of calcium ion ([Ca2+]i) in a small cell lung carcinoma (SCLC) cell line, SBC-3. The [Ca2+]i increase by photodynamic stimulation was completely inhibited by the removal of extracellular Ca2+ and reintroduction of extracellular Ca2+ immediately led to a rapid elevation of [Ca2+]i. However, the increase was not inhibited by application of Ni2+, nifedipine, or SKandF 96365, a receptor-mediated and voltage-dependent Ca2+ entry blocker. The photosensitizer AlPcS4 alone or light alone (4 min) had no effect on [Ca2+]i. Cytotoxicity examination by trypan blue exclusion test, however, suggested photodynamic stimulation-induced cell injury which was observed in both the presence and the absence of extracellular Ca2+. These results indicate that [Ca2+]i increase may not be mandatory for photodynamic stimulation-induced cell injury. Whether [Ca2+]i increase can accelerate, at least in part, cell death under the physiological condition, whether the mechanism(s) of cell death can be different in the presence and the absence of extracellular Ca2+, and whether [Ca2+]i increase can be totally unrelated to cell death await further work

The purpose of this study was to evaluate the relationship between the results of laboratory examinations and ultrasonographic findings, especially portal vein hemodynamics in experimentally bile duct ligated dogs. Biliary obstruction was accomplished by surgically occluding the common bile duct in five dogs. All the dogs became visibly jaundiced within 24 hours after surgery. The total protein and albumin/globulin ratio showed a gradual decrease throughout the examination period, while blood urea nitrogen reached its peak in the 6th week and decreased to pre ligation values by the 10th week. Similar trends were noted in the alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and direct and total bilirubin. Total cholesterol and fasting serum bile acid levels rapidly increased after surgery to peak values between the 2nd and 4th week, and then gradually decreased, but still remained high throughout the experiment period. The portal flow volume and velocity significantly (p0.05) decreased while only a slight increase was noted in the congestion index after bile duct ligation. The cross sectional area of the portal vein changed insignificantly. Bile duct and gallbladder distention was evident within the 1st week after ligation but there was little change in the echogenicity of the liver parenchyma. The results of this study suggest that the determination of Doppler ultrasound parameters of hepatic hemodynamics, especially the portal vein flow indices, may contribute to a better noninvasive assessment of the canine patient with biliary obstructive disease

This paper reviews the alkaline phosphatases in canine serum, the analytical methods used for qualitative and/or quantitative detection of these isoenzymes, and the diagnostic significancy of each of these isoenzymes. The paper further describes some of the latest advances of our knowledge of the canine alkaline phosphatases and possible areas of future research

The cryopreservation of mammalian embryos has become an integral part of method s to control animal reproduction. Numerous vitrification solutions have been formulated with ethylene glycol in combination with macromolecules, sugars and other cryoprotective agents. These indicate that a study of ethylene glycol as a cryoprotectant of choice in vitrification studies would be promising. To understand the cryobiology of ethylene glycol, several factors have to be studied. These are : cryoprotectant toxicity, osmotic stress and temperature at exposure. Understanding these factors could lead to the formulation of vitrification protocols that would lead to higher viability rates after cooling. First, ethylene glycol must be used as the sole cryoprotectant in a solution without macromolecules and sugars. Second, partial dehydration and permeation prior to cooling to subzero temperatures must be studied to achieve accurate exposure and a one-step dilution method. Third, the toxic effects of ethylene glycol must be overcome without sacrificing its vitrification properties by combining step-wise exposure at appropriate temperatures, low concentration and decreased volume. Fourth, the long-term effects of ethylene glycol on exposed or vitrified embryos must be determined. Lastly, the influence of culture on the viability of vitrified embryos must be studied to improve viability rates after warming

The in vitro differentiative potential of mouse parthenogenetic (PG) embryonic stem (PGES) cells were investigated in the formation of embryoid bodies (EBs). EBs derived from PGES cells retarded in growth and showed restricted differentiation compared to their fertilized counterpart. In chimeric EBs from the aggregation of PGES and fertilized ES cells, morphological examination revealed that PGES cells were reduced in their population and distributed in endodermal layer as culture periods proceeded. These findings were comparable to those in aggregation chimeras of fertilized and PG embryos, and suggest that the differentiation of PGES cells in vitro is restricted in the formation of EBs

Murine parthenogenetic embryonic stem (ES) cell lines expressing lac zeta reporter gene were isolated after co-transfection with lac zeta reporter gene (pENL) and neoR gene (pSTneo) to TMA-48P cell line of 129/Sv origin. Karyotype analyses showed that all of four transfected cell lines examined contained 41 chromosomes with trisomy 8. Bacterial neoR transgene required for G418 selection were integrated into several chromosomes including chromosome 8. Histological studies of teratomas formed in syngenic mice and embryoid bodies grown in vitro showed that the differentiative potential remained almost identical in chromosomally normal parental cell line and its derivative cell lines trisomic for chromosome 8

Ovulated mouse oocytes denuded of their cumulus cells, were vitrified in a solution containing 7 M ethylene glycol as the sole cryoprotectant using one or two steps of exposure before vitrification and were diluted in 1 M sucrose solution in 5 or 10 min after warming. The results proved that the viability of oocytes are detrimentally affected by exposure to the vitrification solution even without vitrification. At 5 min dilution time, the two-step exposure was superior to the one-step in terms of the post-warming recovery rate of vitrified oocytes with normal morphology and their subsequent development to the blastocyst stage (p0.001) after fertilization in vitro. At 10 min dilution time, no significant difference between one or two-step exposure was found. The effect of the addition of 0.5 M sucrose to the vitrification solution was also determined and did not result in a significant improvement in the viability of oocytes vitrified in one-step and diluted for 10 min. In conclusion, the results in this study indicate that oocytes can be vitrified with 7 M ethylene glycol as the sole cryoprotectant in the vitrification solution, and that the recovery of normal oocytes after one-step exposure in the vitrification solution can be improved by 10 min dilution time. However, the improvement in the recovery rate of oocytes with normal morphology and their subsequent developmental in vitro was not improved by the addition of 0.5 M sucrose to the vitrification solution

For detecting Borna disease virus (BDV) genomic stranded RNA, single-tube reverse transcription-polymerase chain reaction (St RT-PCR) was developed to equal the sensitivity of RT-nested PCR but with reduced risk of contamination. BDV-genomic stranded RNA was synthesized in vitro using plasmid cDNA of BDV p24 region as a template and RNA was also extracted from BDV-persistently infected MDCK (MDCK/BDV) cells. Both RNAs were amplified by St RT-PCR in which a single round of RT and a single round of PCR were performed in the same tube. Ten copies of synthesized RNA could be amplified by St RT-PCR, indicating that St RT-PCR method is as sensitive as the ordinary RT-nested PCR method. Furthermore, this method was applied to quantify the exact copy number of genomic RNA in MDCK/BDV cells. Signals were obtained from the samples containing more than 1 pg total cellular RNA. From the results, approximately 100 copies of BDV genomic RNA exist in one MDCK/BDV cell. BDV genomic RNA from the in vivo RNA samples using St RT-PCR, indicating this method is applicable for the epidemiological study of BDV without contamination

Mouse metaphase two (M two) oocytes were exposed to 50 mug/ml etoposide (ETO) before and after parthenogenetic activation with 7% ethanol and they were washed with 0.75 M sucrose. The ETO treated parthenogenetically activated oocytes were cultured or fused to single blastomeres of late 2-cell stage mouse embryo to test their ability to support development in vitro. In parallel untreated parthenogenetically activated oocytes were cultured to serve as control. None of ETO treated oocytes developed beyond the 2-cell stage, whereas 4% of the reconstituted embryos and 35% of control developed to blastocysts. It is concluded that mouse M two oocytes can be functionally enucleated by ETO treatment and can be used for nuclear transfer experiments