Cryopreservation of primary porcine hepatocytes for use in bioartificial liver support systems.
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Biomedical subjects
Publications and source records attributed to L Wang.
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Polychlorinated organic compounds (PCOCs) were analyzed in Yangtse River sediments. The results show that the concentrations of PCOCs in Yangtse River sediments followed the order of DDTs > HCB > HCHs > PCBs. High PCOCs concentrations were detected in sediments from station Y02a and Y02b, which are located in the main input of the Yangtse River (Nanjing section). Results also show that the PCOCs values were highly correlated with organic carbon content and heavy metal contamination.
The solubilization of four pairs of substituted indole compounds (SICs) by beta-cyclodextrin (beta-CD) in water was investigated. The results show that 1,2,3,4-tetrahydrocarbazole and N-methyl-1,2,3,4-tetrahydrocarbazole form 1:1 inclusion complexes with beta-CD, while the other six SICs form 1:2 inclusion complexes, respectively. To each pair of SICs with similar structures, the differences between their solubilization in beta-CD/water solutions has been explained by the difference of their contact area within the beta-CD cavity, the difference of their molecule polarity, or the presence of hydrogen bond between SIC molecule and beta-CD molecule.
The photocatalytic degradation performance of photocatalysts TiO2 supported on 13-X, Na-Y, 4A zeolites with different loading content was evaluated using the photocatalytic oxidation of dyes direct fast scarlet 4BS and acid red 3B in aqueous medium. The results showed that the best reaction dosage of TiO2-zeolite catalysts is about 2 g/l and the photocatalytic kinetics follows first order for all supported catalysts. The photocatalytic activity order of the three series catalysts is 13X type >Y type >4A type. The physical state of titanium dioxide on the supports is evaluated by X-ray photoelectron spectra (XPS), powder X-ray diffraction (XRD), BET, and FTIR.
Cannabinoids, the bioactive ingredients of the marijuana plant, are best known for their psychoactive properties, but they also influence other physiological processes, such as cardiovascular variables. Endocannabinoids are recently identified lipid mediators that act as natural ligands at cannabinoid receptors and mimic most of the biological effects, including the cardiovascular actions, of plant-derived cannabinoids. In experimental animals, the most prominent component of the cardiovascular effects of cannabinoids is prolonged hypotension and bradycardia. This review focuses on the possible mechanisms underlying these effects. The emerging evidence suggesting that endocannabinoids may be involved in the peripheral regulation of vascular tone under certain conditions is also discussed.
BACKGROUND: There have been reports from physicians in clinical practice that up to 30% of patients taking bisphosphonate therapy develop upper gastrointestinal (UGI) symptoms, many or most of which they assume to be related to the drug. However, in several large placebo-controlled clinical trials of bisphosphonates, the incidence of UGI symptoms has been > or =30%, even among patients receiving placebo, perhaps reflecting a high background incidence of UGI events in osteoporotic patients. OBJECTIVE: To assess the relationship between alendronate treatment and UGI complaints in patients who had discontinued treatment with alendronate in clinical practice because of UGI symptoms, we compared the incidence of such events on rechallenge with alendronate or placebo. METHODS: This was a multicenter, double-blind trial in which postmenopausal women with osteoporosis who had previously discontinued alendronate therapy because of a UGI adverse experience were randomized to daily treatment with either alendronate 10 mg or matching placebo (1:1 ratio) for 8 weeks. The primary end point was the cumulative incidence of discontinuations due to any UGI adverse experience. Secondary end points were the incidence of any clinical adverse experiences and the percentage change from baseline in urinary N-telopeptide adjusted for urinary creatinine at week 8. RESULTS: A total of 172 women were included in the study. They were a mean of 20.9 years past menopause, ranging in age from 41 to 90 years (mean, 67.0 years); 90.7% were white. On rechallenge, 14.8% (13/88) of patients in the alendronate group and 16.7% (14/84) in the placebo group discontinued treatment because of UGI adverse experiences. CONCLUSION: The results of this study suggest that many UGI adverse experiences reported during therapy with alendronate may reflect a high background incidence of UGI complaints and an increased sensitivity to detection of such complaints, rather than a causal relationship to therapy.
BACKGROUND: Clinical trials have established the efficacy and safety of botulinum toxin type A (BTX-A) in patients with cervical dystonia. To maintain the clinical benefits of BTX-A, injections need to be repeated whenever patients' symptoms begin to recur. OBJECTIVE: The purpose of this study was to determine, in clinical practice settings, the mean duration of effect of BTX-A in the treatment of adult patients with cervical dystonia. METHODS: A retrospective chart review was undertaken at an academic center and a private neurology practice. At each site, > or =50 patients being treated for cervical dystonia were identified and randomized for chart review. Patients had to have received the first assessable injection of BTX-A between January 1, 1998, and March 31, 1998, to coincide with the clinical availability of the most current formulation of the neurotoxin. A chart was eligible for review if the patient was aged > or =18 years, had a documented diagnosis of idiopathic cervical dystonia, was being treated with BTX-A, and had been under the continuous care of investigators from January 1, 1998, to August 31, 1999. Of the 102 patients initially identified, the first 30 from each site who met the study inclusion criteria were assessed for (1) age and sex; (2) severity of dystonia; (3) years of BTX-A use; (4) dates of first, second, third, and fourth BTX-A injections; (5) drug dose; (6) use of electromyography; (7) use of other prescribed therapies; (8) laboratory tests; and (9) adverse events. The mean interval between each visit and mean per-patient duration of effect were calculated and stratified by patient characteristics. RESULTS: The mean age of the patients was 56.4 years. Two thirds of the patients were women. Forty-one of the 60 patients (68.3%) had either moderate or severe disease, and 48 (80.0%) had experienced cervical dystonia for >5 years. The mean per-patient duration of effect across the 4 visits was 15.5 weeks (range, 12.2-24.3 weeks). The duration of effect did not differ significantly between study sites despite the differences in disease severity, drug dose, and use of adjunctive therapy. CONCLUSION: BTX-A the controls symptoms of cervical dystonia for 12 to 24 weeks, with a mean duration of effect per patient of 15.5 weeks.
OBJECTIVE: This study was undertaken to identify the expected first- and second-year clinical costs associated with intravesical valrubicin therapy, using a decision analytic model, for patients with Bacilli Calmette-Guérin (BCG)-refractory carcinoma in situ (CIS) of the urinary bladder. BACKGROUND: Cancer of the urinary bladder is the fourth most common malignancy in men and the sixth most common noncutaneous carcinoma overall. One histopathologic stage of bladder cancer is CIS, for which BCG intravesical immunotherapy is the first-line therapy. Radical cystectomy has been recommended for patients with CIS who do not respond to or become refractory to therapy with BCG. Surgery, however, may not be appropriate for all patients, especially those who are ineligible for the lengthy procedure because of advanced age or comorbidities and those who prefer alternative nonsurgical management. For these groups, intravesical valrubicin therapy is a plausible alternative. METHODS: Models were developed and populated with data from 1 open-label study of 90 patients, information from the medical literature, and input from clinical experts. The analysis was conducted from the payor perspective for direct costs only. RESULTS: Our data indicate that first- and second-year expected costs for valrubicin therapy are $19,912 and $23,496, respectively. Expected cost for radical cystectomy was also evaluated, since some patients may have no other option if drug therapy fails. CONCLUSION: Our cost-consequence analysis and clinical data provide decision-makers with tools to aid in global budgetary projections of fractional and total expected health care costs associated with the management BCG-refractory CIS of the urinary bladder.
Acenaphtheno[1,2-b]-1,4,8,9-tetraazatriphenylene (atatp) and its complexes [Ru(L)2atatp](ClO4)2 x nH2O (L = 2,2'-bipyridine (bpy), n=2 (1); 1,10-phenanthroline (phen), n=2 (2); and 2,9-dimethyl-1,10-phenanthroline (dmp), n=1 (3)) have been synthesized and characterized by elemental analyses and 1H NMR. The spectral and electrochemical properties of these complexes are also examined. Complexes 1 and 2 display bright luminescence in acetonitrile but very weak luminescence in water solution. However, complex 3 is not luminescent in either solvent. The interaction of the complexes with calf thymus DNA (CT-DNA) has been studied by absorption, emission and viscosity measurements. The intrinsic binding constants of complexes 1 and 2 are 7.6 x 10(4) and 8.8 x 10(4) M(-1) respectively. The relatively low affinities of complexes 1 and 2 with DNA may arise from the atatp ligand, indicating that the size and shape of the intercalated ligand have a marked effect on the strength of interaction. Complexes 1 and 2 bind with CT-DNA in an intercalative mode but complex 3 in a non-intercalative one, showing that changing the ancillary ligand affects not only the binding magnitude, but also the binding mode of the interaction.
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Neurons synthesizing thyrotropin-releasing hormone, substance P and serotonin in the medullary caudal raphe nuclei project to the dorsal vagal complex and play a role in the central vagal regulation of gastric function. Neurons in the parapyramidal region in the ventral medulla share similar biochemical coding and projections as those in the caudal raphe nuclei. The role of the parapyramidal region in the autonomic regulation of gastric acid secretion was investigated in urethane-anesthetized rats. Unilateral microinjection of kainate into the parapyramidal region at 10, 15 and 20 ng induced a dose-related stimulation of gastric acid secretion (net increases: 22.2+/-11.2, 40.5+/-8.5 and 89.8+/-19.4 micromol/60 min, respectively), while injection of vehicle had no effect (net change: -0.1+/-1.4 micromol/60 min). Time-course studies showed a nine-fold peak increase over basal at 30 min after parapyramidal injection of kainate (20 ng) and acid secretion returned to basal level at 70 min. Microinjections of kainate (15-20 ng) outside the parapyramidal region or into the parapyramidal region in vagotomized rats had no effect. Exposure to cold (4 degrees C) for 2 h, which is known to induce vagally mediated gastric secretory and motor responses through medullary thyrotropin-releasing hormone pathways, increased the number of Fos-positive cells in the caudal, middle and rostral parts of the parapyramidal region to 4.3+/-0.4, 9.4+/-0.9 and 18.4+/-1.6/section, respectively, compared with 0.1+/-0. 1, 0.1+/-0.0 and 0.7+/-0.6/section, respectively, in rats maintained at room temperature. Most of the Fos-labeled cells co-expressed pro-thyrotropin-releasing hormone messenger RNA signal and/or were serotonin immunoreactive. These data show that chemical activation of neurons in the parapyramidal region results in a vagal-dependent stimulation of gastric acid secretion and that acute cold exposure activates parapyramidal neurons containing pro-thyrotropin-releasing hormone and/or serotonin, suggesting a potential role of the parapyramidal region, in addition to the caudal raphe nuclei, as medullary sites involved in the vagal regulation of gastric function.
We have previously shown that serum gonadotropins, particularly LH, decline after acute exercise in male volunteers. The mechanism for this decline is unknown. Plasma leptin and IGF-I concentrations were measured in seven male volunteers after acute exercise to exhaustion using the Bruce protocol. Leptin concentrations declined following exercise reaching nadir values 30-120 min after exercise. As anticipated, plasma IGF-I concentrations showed a transient rise immediately after exercise falling thereafter to nadir levels 60-90 min after exercise before returning towards baseline levels. In view of the previously described decline in gonadotropin release after acute exercise, the decline in plasma leptin levels, perhaps related to the rise in IGF-I, may play a role in exercise-induced inhibition of gonadotropin release presumably by inhibition of GnRH secretion.
To investigate the relationships between carbamazepine (CBZ) concentrations in serum and the brain, and the anticonvulsive efficacy in kainic acid (KA) induced seizures in rats, adult Wistar rats (n=25) were intraperitoneally given 40 mg/kg CBZ, followed by 15 mg/kg KA (n=20) or saline (control, n=5). At 90 min after the injection, CBZ concentrations in 5 rats without seizures (CBZ effective group), 5 rats with seizures (CBZ no-effective group) and five control rats were measured. Serum and brain tissues from six areas (cortex, brain stem, cerebellum, thalamus, hippocampus and striatum) were used for CBZ assay. CBZ was measured using a EMIT immunoassay kit. In blood, CBZ was higher in rats treated with CBZ+KA than in a control group (CBZ+saline). In the brain, the effective group demonstrated significantly high CBZ concentration in the hippocampus. KA appeared to raise serum CBZ level when it was given in combination with CBZ. This was probably caused by the accelerated absorption of CBZ from local site as the results of an increased metabolic rate and the more demands for blood supply after KA treatment. The positive correlation between efficacy of CBZ and the concentration in the hippocampus suggests that CBZ levels in the hippocampus is closely correlated with the efficacy of CBZ against KA induced seizures.
Simvastatin, a highly effective cholesterol-lowering agent, has been widely used for the treatment of hypercholesterolemia. During the development of simvastatin solid dosage form, formulation compositions were constantly varied to define a suitable matrix. A fast and reliable method for the dissolution and release testing of simvastatin was highly desirable to support formulation screening. A second derivative UV spectroscopic method was developed for determination of simvastatin in the tablet dosage form. After carefully choosing a zero-crossing technique of second derivative UV measurement at 243 nm, the selectivity and sensitivity of simvastatin was comparable to the previously developed HPLC method. In comparison with the direct UV method, second derivative UV spectroscopy eliminates the interference from UV absorbing excipients such as ascorbic acid, which often results in a bias of 2-10%. This method is also fast and economical in comparison to the more time-consuming HPLC method regularly used for formulation screening. Finally, this method has been validated to be precise and accurate, and is demonstrated to be an excellent alternative to HPLC method for the dissolution and release testing of simvastatin in the solid dosage form.
PURPOSE: To evaluate corneal topography in a series of keratoconus patients using the Orbscan Topography System. SETTING: Department of Ophthalmology, Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany. METHODS: Seventy-one eyes of 38 patients with keratoconus were evaluated. Quantitative topographic parameters were analyzed with special reference to the central point of the cornea, the apex (the point with maximum reading on the anterior elevation best-fit sphere map), and the thinnest point. Evaluation included location, elevation (compared to a best-fit sphere), pachymetry, tangential curvature, and composite curvature. The mirror-image symmetry between the right and left eyes of a patient was also investigated. RESULTS: Mean patient age was 31.2 years +/- 12.2 (SD). Thirty-three patients (86.8%) had bilateral keratoconus and 5 (13.2%), unilateral keratoconus. Most cones (68/71) were located in the inferior temporal quadrant; 3 were above the horizontal meridian. Mean distance between the apex and the thinnest point was 0.917 +/- 0.729 mm (P < .001). The correlations between apex elevation and apex composite curvature and apex tangential curvature were high (r = 0.94 and r = 0.91, respectively; P < .001). In right and left eyes, there was a correlation between the apex and the thinnest point semi-meridians (r = 0.47 and r = 0.65, respectively; P < .05) but not between the radii of the apex and the thinnest point (r = 0.21 and r = 0.24, respectively). CONCLUSIONS: The Orbscan system can provide useful and accurate information in defining the morphology of keratoconus and detecting subtle topographic changes present in early keratoconus. It may also improve the results of contact lens fitting and surgical management.
Oral ulcerative mucositis is a common toxicity associated with drug and radiation therapy for cancer. It impacts on quality of life and economic outcomes, as well as morbidity and mortality. Mucositis is often associated with dose limitations for chemotherapy or is a cause for dose interruption for radiation. The complexity of mucositis as a biological process has only been recently appreciated. It has been suggested that the condition represents a sequential interaction of oral mucosal cells and tissues, pro-inflammatory cytokines and local factors such as saliva and the oral microbiota. The recognition that the pathophysiology of mucositis is a multifactorial process was partially suggested by the observation that interleukin-11 (IL-11), a pleotropic cytokine, favorably altered the course of chemotherapy-induced mucositis in an animal model. In the current study, we evaluated a series of biologic and morphologic outcomes to determine their roles and sequence in the development of experimental radiation-induced mucositis and to evaluate the effects of IL-11 in attenuating them. Our results suggest that IL-11 favorably modulates acute radiation-induced mucositis by attenuating pro-inflammatory cytokine expression. Data are also presented which help define the pathobiological sequence of mucositis.
In this paper we address three areas. First we review the literature on clinical intervention using debriefing, second we examine who attends debriefings by looking at a study of the 1989 plane crash at Ramstein, Germany and lastly we examine the effect of natural debriefing, i.e., talking to family and friends on psychiatric outcome in disaster workers by looking at a study of the Sioux City, Iowa United plane crash, 1989. Our data suggest that those with high exposure and females were more likely to attend a debriefing. People most likely to talk about the disaster with spouse/significant other, coworker and/or another person were: those with acute PTSD, higher total and intrusive Impact of Event symptoms, older, married, those with higher levels of education and higher levels of disaster exposure. Better understanding of who attends formal debriefings will help identify potential high-risk groups. Similarly, whether talking about the disaster is associated with fewer or greater psychological symptoms is important to understanding the outcome, mechanisms, and risks of debriefing.