Tissue distribution and physiologically based pharmacokinetics of antisense phosphorothioate oligonucleotide ISIS 1082 in rat

The aim of this study was to develop a whole body physiologically based model of the pharmacokinetics (PBPK) of the phosphorothioate oligonucleotide (PS-ODN) ISIS 1082 in vivo. Rats were administered an intravenous (i.v.) bolus dose of ISIS 1082 (10 mg/kg plus 3H tracer), and arterial blood and tissues were taken at specific times up to 72 hours. Radioactivity was measured in all samples. The parent compound was determined specifically in blood and tissues at 90 minutes and in liver and kidney also at 24 hours, using capillary gel electrophoresis (CGE). A whole body PBPK model was fitted to the combined blood and tissue radioactivity data using nonlinear regression analysis. CGE analysis indicated that the predominant species in plasma and all tissues is ISIS 1082, together with some n-1 and n-2 metabolites. Total radioactivity primarily reflects these species. The whole body model successfully described temporal events in all tissues. However, to adequately model the experimental data, all tissues had to be partitioned into vascular and extravascular spaces to accommodate the relatively slow distribution of ISIS 1082 out of blood because of a permeability rate limitation. ISIS 1082 distributes extensively into tissues, but the relative affinity varies enormously, being highest for kidney and liver and lowest for muscle and brain. A whole body PBPK model with a permeability rate limited tissue distribution was developed that adequately described events in both blood and tissue for an oligonucleotide. This model has the potential not only to characterize the events in individual tissues throughout the body for such compounds but also to scale across animal species, including human.

[A study on the pathogenesis of Streptococcus mitis exotoxin]

OBJECTIVE

To study the isolation, purification and pathogenesis of Streptococcus mitis pyrogenic exotoxin causing toxic shock syndrome.

METHODS

Streptococcus mitis isolated from patients' throat were shaking cultivated. After being centrifuged, the supernatant fluid of the culture was precipitated with 20%, 40%, 60%, 80% (NH(4))(2)SO(4) respectively and the fast protein liquid chromatography(FPLC) was used for the final step of purification. Rabbits receiving subcutaneous injection with respective purified proteins were monitored daily for fever. The ability of the purified proteins to enhance the susceptibility of the rabbits to lethal Escherichia coli endotoxin shock is recorded, when the endotoxin was injected intravenously 4 hours after administration of 10 microg Streptococcus mitis exotoxin.

RESULTS

Only the protein precipitated by 20% (NH(4))(2)SO(4) (molecular weight is 34,000) from culture supernatant fluid was pyrogenic for rabbits (average temperature increase near 1 degrees C), and it can also cause the proliferation of rabbit splenocytes (mitogenicity). All the animals receiving subcutaneous injection of exotoxin containing purified proteins precipitated with higher concentrations of (NH(4))(2)SO(4) died within 16 approximately 29 hours after intravenous injection of the Escherichia coli endotoxin, demonstrating the enhanced susceptibility of the animals to lethal endotoxin shock. The control rabbits displayed none of these effects.

CONCLUSION

Streptococcus mitis exotoxin is a novel streptococcal pyrogenic exotoxin.

Construction and in vitro expression of Streptococcus mutans surface protein encoding DNA vaccine

DNA vaccine plasmids were constructed that encoded two highly-conservative regions of a surface protein, PAc, from the human major cariogenic bacterium, Streptococcus mutans. Antigen expression was evaluated in vitro by immunohistochemical analysis of human endothelial cells following cationic liposome-mediated transient transfection with recombinant plasmid. The results of this study provided a basis for further testing of these recombinant plasmids in primates and for efficacy testing of dental caries DNA vaccines in human volunteers in future.

Cytogenetic studies of three triazine herbicides. II. In vivo micronucleus studies in mouse bone marrow

Atrazine, simazine, and cyanazine are widely used preemergence and postemergence triazine herbicides that have made their way into the potable water supply of many agricultural communities. Although there are several contradictory genotoxicity studies in the literature, our previous in vitro studies with human lymphocytes showed that atrazine, simazine, and cyanazine did not induce sister chromatid exchanges (SCEs) or chromosome aberrations (CAs) up to the limits of solubility in aqueous medium using 0.5% dimethyl sulfoxide. To expand upon these results and to ensure that our in vitro findings could be replicated in an in vivo system, mice were treated with each triazine by two intraperitoneal injections, 24h apart. The animals were sacrificed and the bone marrow removed for micronucleus (MN) analysis, 24h after the last injection. Two to four independent trials were performed for MN analysis in polychromatic erythrocytes, and in some trials the spleen was removed, cultured, and analyzed for SCEs and CAs. None of the triazines investigated induced MN in the bone marrow, even at doses that caused significant bone marrow suppression and/or death. These results indicate that atrazine, simazine, and cyanazine are not genotoxic as measured by the bone marrow MN assay in mice following high dose exposures.

Cross-protection in NYVAC-HIV-1-immunized/HIV-2-challenged but not in NYVAC-HIV-2-immunized/SHIV-challenged rhesus macaques

OBJECTIVES

Immunization with attenuated poxvirus-HIV-1 recombinants followed by protein boosting had protected four of eight rhesus macaques from HIV-2SBL6669 challenge. The present study was designed to confirm this result and to conduct the reciprocal cross-protection experiment.

METHODS

Twenty-four macaques were primed with NYVAC (a genetically attenuated Copenhagen vaccinia strain) recombinants with HIV-1 and HIV-2 env and gag-pol or NYVAC vector alone and boosted with homologous, oligomeric gp160 proteins or adjuvant only. Binding and neutralizing antibodies, cytotoxic T-lymphocytes (CTL) and CD8 T cell antiviral activity (CD8AA) were evaluated. One half of each immunization and control group were intravenously challenged with SHIV(HXB2) the other half was challenged with HIV-2SBL6669,. Protective outcome was assessed by monitoring virus isolation, proviral DNA and plasma viral RNA.

RESULTS

Both immunization groups developed homologous binding antibodies; however, homologous neutralizing antibodies were only observed in NYVAC-HIV-2-immunized macaques. While no cross-reactive neutralizing antibodies were detected, both immunization groups displayed cross-reactive CTL. Significant CD8AA was observed for only one NYVAC-HIV-2-immunized macaque. Virological assessments verified that both NYVAC-HIV-1 and NYVAC-HIV-2 immunization significantly reduced viral burdens and partially protected against HIV-2 challenge, although cross-protection was not at the level that had been previously reported. Humoral antibody and/or CTL and CD8AA were associated with protection against homologous HIV-2 challenge, while cellular immune responses seemed more important for cross-protection. No significant protection was observed in the SHIV-challenged macaques, although NYVAC-HIV-1 immunization resulted in significantly lower viral burdens compared with controls.

CONCLUSIONS

Further delineation of cross-reactive mechanisms may aid in the development of a broadly protective vaccine.

Effect of P-glycoprotein modulation on the clinical pharmacokinetics and adverse effects of morphine

AIMS

To investigate the effect of acute P-glycoprotein inhibition by the multidrug-resistance (MDR) modulator valspodar (SDZ PSC 833; PSC) on the pharmacokinetics, and potentially adverse pharmacodynamic effects of morphine, and its principal pharmacologically active metabolites, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G).

METHODS

In a double-blind, three-way crossover study, the pharmacokinetic and potentially adverse pharmacodynamic effects (reaction time, transcutaneous PCO2, blood pressure) of morphine were compared with and without acute inhibition of P-glycoprotein by PSC. The effects of PSC alone were also evaluated. The study was performed in 18 healthy male volunteers and pharmacodynamic effects analysed by measuring the area under the effect (AUE) curve. 150 mg PSC (or its placebo) was given as an i.v. infusion over 2 h. With the expected inhibition of Pgp 1 h after starting PSC infusion, 7.5 morphine HCl (or its placebo) was infused over 2 h.

RESULTS

The infusion of PSC resulted in blood concentrations expected to inhibit Pgp mediated transport. While the pharmacokinetics of plasma morphine and M6G. were unaffected there was a small but statistically significant increase in the AUC and Cmax of M3G (11.8 and 8.3%, respectively). The t(1/2) and tmax were unaffected. The pharmacokinetic parameters of PSC were not affected by coadministration with morphine. PSC did not significantly affect the adverse events of morphine, as assessed by spontaneous reporting. Compared with PSC alone, morphine elicited an increase in reaction time (Emax 48 ms, compared with the predose absolute reaction time of 644 ms), which was not detected by the alertness-drowsiness score, indicating only slight sedation. There was a significant decrease in systolic blood pressure (Emin -9 mm Hg), and a trend for a fall in diastolic blood pressure (Emin -14.5 mm Hg) and respiratory rate (Emin -1.8 breath x min(-1)). For all these parameters, the effects of PSC/morphine were similar to that of PSC alone, suggesting some attenuation of morphine's effect. In contrast, morphine caused a significant increase in PCO2 (Emax 0.69 kPa) compared to PSC alone, indicating slight respiratory depression. This increase was similar to that of the PSC/morphine combination.

CONCLUSIONS

Acute inhibition of P-glycoprotein by PSC in this setting does not affect the pharmacokinetic or safety-related pharmacodynamic profile of morphine in a clinically significant manner.

In situ hybridization analysis of transforming growth factor-beta 1 RNA expression during mouse tooth development

OBJECTIVE

The aim of this study is to investigate the temporal and spatial expression and localization of transforming growth factor-beta 1 mRNA during mouse tooth development.

METHODS

The distribution pattern of TGF-beta 1 mRNA during tooth development was analyzed on 5 microns serial sections of paraformaldehyde-fixed and paraffin-embedded embryonic mouse heads or mandibles.

RESULTS

The results show that TGF-beta 1 mRNA is expressed during mouse tooth development in a temporally and spatially regulated fashion. Local expression of TGF-beta 1 mRNA in the dental epithelium at budstaged (E13) and capstaged (E15) teeth were observed. During bell stage (E16-18), TGF beta 1 mRNA was very abundant in the ameloblast layer and dental papilla cells. The expression of TGF-beta 1 increased in the layer of odontoblast and ameloblast with the differentiation of these cells.

CONCLUSION

These results suggest that TGF-beta 1 may have an important role in odontogenesis and that it acts as a paracrine and autoinducing factor.

[Abnormal P3 latency in obstructive sleep apnea syndrome, but normal in snore]

OBJECTIVE

To evaluate the P3 wave (latency, amplitude) in snorers and patients with obstructive sleep apnea syndrome (OSAS) and investigate the possible mechanism.

METHODS

Three groups, OSAS patient group (n = 21), snorer group (n = 21) and control group (n = 21), were administered polysomnography (PSG), auditory evoked event-related potential (P3) and clinic memory test. The results were analyzed using GLM analysis and Post Hoc test.

RESULTS

The auditory P3 latency in OSAS group was 363 ms +/- 22 ms (Fz), 369 ms +/- 28 ms (Cz), in snorer group 336 ms +/- 31 ms (Fz), 340 ms +/- 32 ms (Cz), and in control group 341 ms +/- 29 ms (Fz), 338 ms +/- 30 ms (Cz). There were significant differences between OSAS group and snorer group, as well as control group (P < 0.05). No significant difference was seen between snorer group and control group. Memory quotient (MQ) was reduced in snoren group as compared with control group.

CONCLUSION

Abnormal auditory P3 latency indicates the cognitive dysfunction in OSAS patients. Nocturnal hypoxaemia may play an important role.

[A new potential promoter region of the human connexin 26 gene]

OBJECTIVE

To explain regulatory mechanism of the human connexin 26(Cx26) gene.

METHODS

A DNase-1 hypersensitive 1.6 kb fragment upstream of the 5'-terminus of the Cx26 gene was sequenced and assayed with CAT reporter system.

RESULTS

The Cx26-1.6 kb sequence serves as a powerful promoter.

CONCLUSION

The Cx26-1.6 kb fragment contains two GT boxes (centering at-6158 and -6213 bp), and a TATA-less TTAAAA box (-6237/-6232 bp) which is another promoter region of the human Cx26.

[Clinical application of artificial blood vessel graft for arteriovenous fistulization]

OBJECTIVE

To investigate the clinical application of artificial blood vessel graft for arteriovenous fistulization.

METHODS

From October 1995 to August 1998, 23 cases with renal failure received PTEF artificial vessels grafting for arteriovenous fistulization in the forearm. The PTFE artificial vessel was 6 mm in diameter, and 40 cm in length. Artificial vessel "U"-shaped loop was formed from elbow incision to wrist incision, and perfused by 20 ml heparin saline. The two ends of artificial vessel were end-to-side anastomosed with superficial cubital vein and cubital artery respectively.

RESULTS

All of arteriovenous fistulas were successfully formed, and could be performed hemodialysis periodically. The artificial vessels could be punctured repeatedly, and had sufficient volume of blood flow. It had no rejection, no formation of false aneurysm, and no ischemia in arm or exacerbated reflux to heart.

CONCLUSION

The artificial vessel grafting for arteriovenous fistulization is a safe and convenient technique in clinical practice, especially when there is no autogenous vessels for arteriovenous fistula.

[The relationship between cartilage end-plate calcification and disc degeneration: an experimental study]

OBJECTIVE

To study the relationship between cartilage end-plate calcification and intervertebral disc degeneration.

METHODS

An experimental model of cervical disc degeneration in rabbits was established by resection of cervical supraspinous and interspinous ligaments and detachment of the posterior paravertebral muscles from cervical vertebrae. Mechanical instability in the cervical spine elicited by this surgical intervention accelerated the process of intervertebral disc degeneration. The degrees of intervertebral disc degeneration were graded morphologically. The thickness of the calcified layer and the uncalcified layer of the cartilage end-plate was measured in each degenerated cervical disc.

RESULTS

A positive correlation existed between the thickness of the calcified layer of the cartilage end-plate and the degree of the cervical disc degeneration (r = 0.92).

CONCLUSION

The calcification of the cartilage end-plate could initiate and promote intervertebral disc degeneration.

Targeted deletion of the Vgf gene indicates that the encoded secretory peptide precursor plays a novel role in the regulation of energy balance

To determine the function of VGF, a secreted polypeptide that is synthesized by neurons, is abundant in the hypothalamus, and is regulated in the brain by electrical activity, injury, and the circadian clock, we generated knockout mice lacking Vgf. Homozygous mutants are small, hypermetabolic, hyperactive, and infertile, with markedly reduced leptin levels and fat stores and altered hypothalamic proopiomelanocortin (POMC), neuropeptide Y (NPY), and agouti-related peptide (AGRP) expression. Furthermore, VGF mRNA synthesis is induced in the hypothalamic arcuate nuclei of fasted normal mice. VGF therefore plays a critical role in the regulation of energy homeostasis, suggesting that the study of lean VGF mutant mice may provide insight into wasting disorders and, moreover, that pharmacological antagonism of VGF action(s) might constitute the basis for treatment of obesity.

[Kinin generation in acute and chronic airway inflammation]

OBJECTIVE

To investigate the kinin generation pathways in acute and chronic airway inflammation.

METHODS

BALF from patients with acute, chronic airway inflammation and healthy controls were collected. Kinins, Plasma kallikrein, alpha 2-macroglobulin and toluenesulphonyl-arginine methyl ester esterase activity (TAME-ea) in BALF were studied.

RESULTS

Kinins and TAME-ea values were significantly higher in the BALF of patients with acute and chronic airway inflammation than those in the controls, but there was no significant difference between acute and chronic groups; PK and alpha 2-M values were significantly higher in the acute group than the in chronic one. Gel filtration revealed the highest TAME-ea peak at about 800,000 in the acute group, corresponding with the first alpha 2-M peak, whereas at about 40,000 in chronic bronchitis. The inhibition test of the TAME-ea showed that the TAME-ea peak at 800,000 was mainly due to PK and the TAME-ea peak at 40,000 was mainly due to TK.

CONCLUSIONS

The results indicated that in acute airway inflammation kinins seem to be mainly generated by PK, whereas in chronic inflammation kininogenases other than PK--such as TK--seem to be more important.

[Transcriptional activation study of transforming gene Tx-related human nasopharyngeal carcinoma]

Tx gene is the DNA sequence with transforming activity which was cloned from the epithelial cell line (CNE2) of human nasopharyngeal carcinoma(NPC). The goal of this study is to find transcriptional activated site on the Tx 2.8 kb fragment using DNase-I hypersensitivity assay, by which understanding the role of the Tx in carcinogenesis of NPC. The results showed no DNase-I hypersensitivity site on the fragment. It suggests that Tx 2.8 kb fragment homogenous to Ig kappa C might be regulated by the specific mechanism of immunoglobulin gene, rather than that of oncogenes.

[Mechanism of Canscora lucidissima xanthones against arrhythmia induced by myocardial ischemia-reperfusion in rats]

OBJECTIVE

To study the protective effect of 1,8-dihydroxy-3,5- dimethoxyxanthone (Xan-I) 1-hydroxy-5-dimethoxyxanthone(Xam-II) and 1-hydroxy-3,7,8-trimethoxyanthone (Xan-III) on arrhythmia induced by myocardial ischemia-reperfusion injury and their mechanism.

METHOD

A rat model was used. The experimental result shows that.

RESULT

An intravenous injection of Xan-I, Xan-II and Xan-III 1 mg/kg given 3 min before left coronary artery ligation reduces significantly the incidence of ventricular arrhythmia and its duration, diminishes the release of glutamic oxaloacetic transaminase and lactate dehydrogenase, elevates the activity of superoxide dismutase and reduces the amount of malondialdehyde. The potency of the above effect among 3 Xans is Xan-I > Xan-III > Xan-II.

CONCLUSION

It follows that the protective effect of Xans on myocardial ischemia reperfusion induced by arrhythmia might be associated with the reduction of myocardial lipid peroxidation and the enhancement of SOD activity, and the amount and site of-OH(hydroxy) and -OCH3 (methoxy) on the benzenoid structure may be related to the affinity of Xan.

[Dynamic change of androgen-receptor in tumor and surrounding liver tissue of nude mice model with transplanted human HCC]

OBJECTIVE

To research into the law of androgen-receptor (AR) dynamic change in developing course of human HCC.

METHOD

Dynamic measurement of AR in tumor and peritumorous tissue was performed in nude mice model with orthotopic transplanted human HCC.

RESULT

Tumor nodules were present in 90% nude mice 4 weeks after transplantation, tumor necrosis was found in the 10th week, and remarkable necrosis occurred in the 12th week. The quantity of AR in tumor and peritumorous tissue was highest in the early stage of tumor (102.32 +/- 21.42 fmol/mg protein and 72.45 +/- 10.11 fmol/mg protein respectively), and then decreased progressively with time to the 10th week (40.98 +/- 21.11 fmol/mg protein and 53.39 +/- 7.01 fmol/mg protein respectively). The difference in AR between each two weeks was significant.

CONCLUSION

Androgen promotes the development of tumor because of existence of AR, and its action may decline after establishment of tumor. Therefore, antiandrogen treatment may be ineffective after establishment of tumor.

Regulatory role of T cells in a murine model of lymphoproliferative disease

As NZB mice age, approximately 90% of the 12-month-old mice possess an expansion of malignant B-1 (CD5+ B cells) cells with many similarities to the human lymphoproliferative disease, chronic lymphocytic leukemia. Malignant B-1 cells derived from NZB mice produce significantly higher levels of IL-10 mRNA and protein than normal B-1 or B cells. IL-10 may act as an autocrine growth factor for the expansion of B-1 cells. In this report, the infrequent animals which survived 18 months of age or longer were studied and compared to NZB mice at 12-14 months of age. Analysis of lymphoid subpopulations in the spleen and peritoneal cavity indicated that long-lived NZB mice had an expansion of CD8+ T cells rather than the typical B-1 expansion observed in the majority of NZB animals at 12 months of age. We established a CD8+ T cell clone from long-lived NZB mice which was cytotoxic for malignant B-1 cells of NZB origin both in vivo and in vitro. Analysis of the regulatory mechanisms preventing the development of genetically programmed age-dependent CLL in the murine system may elucidate possible avenues for therapeutic intervention in CLL.

The correlation of telomerase and IL-10 with leukemia transformation in a mouse model of chronic lymphocytic leukemia (CLL)

Telomerase activity is upregulated in activated and malignant lymphocytes. We studied the correlation of telomerase and IL-10 to leukemia transformation in the NZB mouse model of human chronic lymphocytic leukemia (CLL). Telomerase levels increased from early to late leukemic stages, likewise IL-10 gene expression levels increased with the leukemic progression. The inverse relationship of telomerase and IL-10 levels to the survival of NZB mice was also established. Our data suggested that telomerase and IL-10 were involved in transformation in the murine model of CLL and the detection of telomerase activities might be of value in the prediction of CLL progression.

[Effect of Fucong tablets and its ingredients on ototoxicity of gentamycin in guinea pigs]

OBJECTIVE

To assess the antagonistic effect of Fucong Tablet (FCT) and its ingredients on ototoxicity of gentamycin in guinea pigs.

METHODS

The guinea pigs were given gentamycin 80 mg/kg intramuscularly once daily for 20 days and FCT or its ingredients separately oral taken for 20 days. The auditory brain stem evoked response (ABR) threshold, vascular stria blood circulation condition, outer hair-cell count and cochlear ultrastructure of guinea pigs were observed before and after treatment to assess the antagonistic effect and protective effect of FCT on cochlear structure.

RESULTS

FCT and its ingredients of tonifying Kidney, replenishing Qi and blood, promoting blood circulation could lower the impairment ratio of outer hair-cell induced by gentamycin (P < 0.05), protect morphosis and function of cochlea and lower the elevated ABR threshold (P < 0.05).

CONCLUSIONS

FCT and its ingredients could reduce the toxic damage on ear induced by gentamycin effectively.

[Effects of fat emulsion on serum lipid, apo A I, apo B100, LCAT, KBR of postoperative patients with liver disorder]

Twenty post-operative patients with liver disorder were divided randomly into two groups. Ten of them received mean 0.82 g.kg-1.d-1 fat emulsion(42% of the total calorie), and the other ten received mean 1.72 g.kg-1.d-1 fat emulsion (52% of the total calorie) via vein during 5 post-operative days. Their serum lipid, apoA I, apoB100, ketone body ratio (KBR), fat clearance, LCAT and so on were investigted. The results suggest that it is safe for liver-disordered patients with slight or even moderate abnormality of liver function to receive mean 0.82 g.kg-1.d-1 and 1.72 g.kg-1.d-1 fat emulsion after operation and the use of mean 1.72 g.kg-1.d-1 fat emulsion will do no harm but good to liver function.

[Hepatectomy for hepatolithiasis treatment of 354 cases]

OBJECTIVE

To evaluate the effect of hepatectomy for hepatolithiasis.

METHOD

354 patients with hepatolithiasis underwent hepatectomy in the past 10 years. The results were analysed retrospectively, including clinical findings, distribution of stones, patterns of operation, postoperative complications, and residual stones. The clinical data of the patients before 1990 were compared with those thereafter.

RESULT

Left hepatolithiasis was the most common form (323 patients). Left lateral lobectomy and left hepatectomy were most commonly employed (91.2%). 166 of the patients underwent concurrent cholangiojejunostomy. 13.8% patients had residual stones, and postoperative complications occurred in 60 patients, including 4 deaths. Few patients were reoperated on and the incidence of residual stones was lower after 1990. 88% the patients showed excellent or good result.

CONCLUSION

Hepatectomy is a procedure for the management of hepatolithiasis, but still requires combined plasty of stenotic intrahepatic bile ducts and cholangiojejunostomy to reduce the incidence of residual stones and recurrence.

[Function analysis of regulative region of transforming gene Tx related to human nasopharyngeal carcinoma]

Tx gene is the DNA sequence with transforming activity which was cloned from the epithelial cell line (CNE2) of human nasopharyngeal carcinoma (NPC). In order to understand the role of Tx in carcinogenesis of NPC, the promoter function of potential promoter region in Tx2. 8 was detected using CAT reporter assay. The results showed that the region has no promoter function. It suggested that Tx2. 8 kb fragment homogenous to IGKC might be regulated by the specific mechanism of immunoglobulin gene.