Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 128
Filter
1.
Waste Manag ; 60: 609-617, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27712943

ABSTRACT

Complex electronic devices entering our recycling systems often generate losses in the whole treatment chain. For better liberation, crucial for the mechanical separation process, the devices are crushed which also generates dusts that are not recovered. This study investigated the relation between the liberation of Printed Circuit Assembly (PCA) and dust generation in the crushing process of two different types of mobile phone samples. The results revealed that the overall PCA grade in both samples was approximately 70% with around 3.4% dust generation. However, the liberation distribution of PCAs differed between mobile phones resulting in better distribution for sophisticated mobile phones due among other things to the initial size of the phones. Further, the dust fractions comprised both noble and valuable metals but also contaminants that need to be taken into account when further processing is planned. A higher gold concentrate was detected in dusts from regular phones since the protective plastic casing crushed more easily thus exposing the PCA surface for grinding.


Subject(s)
Cell Phone , Dust , Electronic Waste , Recycling/methods , Dust/analysis , Particle Size
2.
Waste Manag ; 45: 235-45, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26139137

ABSTRACT

The recycling of Waste Electrical and Electronic Equipment (WEEE) has attracted a notable amount of interest during the last few decades due to the high metal concentrations and substantial increase in the growth rate of WEEE. In addition, higher recovery and recycling rates required by the European Union demand more comprehensive treatment of WEEE. However, complex product design and the presence of harmful substances together with low concentrations of special metals present challenges for processing. This study examines the effect of mechanical treatment of mobile phones on metal concentrations in the printed circuit assembly (PCA) fraction compared to manual dismantling. The designed mechanical treatment process including crushing, sieving, magnetic-, eddy current- and sensor-based separation was able to separate plastics, ferrous metals, PCA and stainless steel for further treatment. The process separated PCA with an efficiency of 85%. However, the quality of the separated PCAs was poor compared with "pure" manually dismantled PCAs. The primary crushing of mobile phones destroys PCAs thus resulting in the loss of especially precious metals used in the connector coatings and in the surface-mounted components. As a result, the theoretical value of the produced PCA fraction is only half compared to using manual dismantling. However, high labour costs in western countries and low capacity may hinder the feasibility of hand dismantling.


Subject(s)
Cell Phone , Electronic Waste/analysis , Recycling/methods , Waste Management/methods , Metals/analysis , Plastics/analysis
3.
Oncogene ; 33(17): 2245-54, 2014 Apr 24.
Article in English | MEDLINE | ID: mdl-23708654

ABSTRACT

Human colorectal cancers are known to possess multiple mutations, though how these mutations interact in tumor development and progression has not been fully investigated. We have previously described the FCPIK3ca* murine colon cancer model, which expresses a constitutively activated phosphoinositide-3 kinase (PI3K) in the intestinal epithelium. The expression of this dominantly active form of PI3K results in hyperplasia and invasive mucinous adenocarcinomas. These cancers form via a non-canonical mechanism of tumor initiation that is mediated through activation of PI3K and not through aberrations in WNT signaling. Since the Adenomatous Polyposis Coli (APC) gene is mutated in the majority of human colon cancers and often occurs simultaneously with PIK3CA mutations, we sought to better understand the interaction between APC and PIK3CA mutations in the mammalian intestine. In this study, we have generated mice in which the expression of a constitutively active PI3K and the loss of APC occur simultaneously in the distal small intestine and colon. Here, we demonstrate that expression of a dominant active PI3K synergizes with loss of APC activity resulting in a dramatic change in tumor multiplicity, size, morphology and invasiveness. Activation of the PI3K pathway is not able to directly activate WNT signaling through the nuclear localization of CTNNB1 (ß-catenin) in the absence of aberrant WNT signaling. Alterations at the transcriptional level, including increased CCND1, may be the etiology of synergy between these activated pathways.


Subject(s)
Adenocarcinoma/genetics , Adenomatous Polyposis Coli Protein/genetics , Colorectal Neoplasms/genetics , Phosphatidylinositol 3-Kinases/genetics , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Adenomatous Polyposis Coli Protein/metabolism , Animals , Cell Nucleus/metabolism , Class I Phosphatidylinositol 3-Kinases , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Cyclin D1/metabolism , Disease Models, Animal , Epistasis, Genetic , Female , Gene Expression , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microsatellite Instability , Phosphatidylinositol 3-Kinases/metabolism , Tumor Burden , Wnt Signaling Pathway , beta Catenin/metabolism
4.
Vet Pathol ; 46(3): 509-13, 2009 May.
Article in English | MEDLINE | ID: mdl-19176502

ABSTRACT

Idiopathic chondrolysis is a human clinical entity typically reported in adolescent individuals. In this brief communication, we report 2 cases of presumptive idiopathic chondrolysis of the femoral head in Cynomolgus macaques and discuss the clinical symptomatology and pathology of the disease. In detail, we describe the histomorphologic changes of idiopathic chondrolysis and compare these findings with those typically observed in the primary differential diagnoses of Legg-Calve-Perthes disease and nonspecific osteoarthritis. Consideration of this entity among differential diagnoses in young Cynomolgus macaques with unilateral osteoarthritis could be important both for laboratory animal veterinarians and pathologists.


Subject(s)
Cartilage Diseases/veterinary , Macaca fascicularis , Monkey Diseases/pathology , Osteoarthritis, Hip/veterinary , Animals , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Cartilage Diseases/drug therapy , Cartilage Diseases/pathology , Female , Monkey Diseases/drug therapy , Naproxen/therapeutic use , Osteoarthritis, Hip/drug therapy , Osteoarthritis, Hip/pathology
5.
Bone Marrow Transplant ; 37(6): 607-14, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16444276

ABSTRACT

Leukocyte adhesion deficiency-1 (LAD-1), a genetic immunodeficiency disease characterized by life-threatening bacterial infections, results from the defective adherence and migration of leukocytes due to mutations in the leukocyte integrin CD18 molecule. Canine LAD (CLAD) represents the canine homologue of the severe phenotype of LAD-1 in children. In previous studies we demonstrated that non-myeloablative stem cell transplantation from matched littermates resulted in mixed donor-host chimerism and reversal of the disease phenotype in CLAD. In this study, we describe two CLAD dogs with less than 2% donor leukocyte chimerism following non-myeloablative transplant. Both dogs are alive more than 24 months after transplant with an attenuated CLAD phenotype resembling the moderate deficiency phenotype of LAD. The improvement in the CLAD phenotype with very low levels of donor CD18(+) leukocytes correlated with the preferential egress of the CD18(+) neutrophils into extravascular sites. The clinical response with very low levels of donor CD18(+) leukocytes in CLAD supports using this model for testing gene therapy strategies since the low levels of gene-corrected hematopoietic cells expected with hematopoietic gene therapy would likely have a therapeutic effect in CLAD.


Subject(s)
Dog Diseases/physiopathology , Leukocyte-Adhesion Deficiency Syndrome/veterinary , Stem Cell Transplantation/methods , Transplantation Chimera , Animals , Disease Models, Animal , Dog Diseases/genetics , Dog Diseases/therapy , Dogs , Leukocyte-Adhesion Deficiency Syndrome/genetics , Leukocyte-Adhesion Deficiency Syndrome/physiopathology , Leukocyte-Adhesion Deficiency Syndrome/therapy , Phenotype , Stem Cell Transplantation/veterinary
6.
Antimicrob Agents Chemother ; 45(10): 2845-55, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11557479

ABSTRACT

The compartmental pharmacokinetics of anidulafungin (VER-002; formerly LY303366) in plasma were characterized with normal rabbits, and the relationships between drug concentrations and antifungal efficacy were assessed in clinically applicable infection models in persistently neutropenic animals. At intravenous dosages ranging from 0.1 to 20 mg/kg of body weight, anidulafungin demonstrated linear plasma pharmacokinetics that fitted best to a three-compartment open pharmacokinetic model. Following administration over 7 days, the mean (+/- standard error of the mean) peak plasma concentration (C(max)) increased from 0.46 +/- 0.02 microg/ml at 0.1 mg/kg to 63.02 +/- 2.93 microg/ml at 20 mg/kg, and the mean area under the concentration-time curve from 0 h to infinity (AUC(0-infinity)) rose from 0.71 +/- 0.04 to 208.80 +/- 24.21 microg. h/ml. The mean apparent volume of distribution at steady state (V(ss)) ranged from 0.953 +/- 0.05 to 1.636 +/- 0.22 liter/kg (nonsignificant [NS]), and clearance ranged from 0.107 +/- 0.01 to 0.149 +/- 0.00 liter/kg/h (NS). Except for a significant prolongation of the terminal half-life and a trend toward an increased V(ss) at the higher end of the dosage range after multiple doses, no significant differences in pharmacokinetic parameters were noted in comparison to single-dose administration. Concentrations in tissue at trough after multiple dosing (0.1 to 10 mg/kg/day) were highest in lung and liver (0.85 +/- 0.16 to 32.64 +/- 2.03 and 0.32 +/- 0.05 to 43.76 +/- 1.62 microg/g, respectively), followed by spleen and kidney (0.24 +/- 0.65 to 21.74 +/- 1.86 and <0.20 to 16.92 +/- 0.56, respectively). Measurable concentrations in brain tissue were found at dosages of > or =0.5 mg/kg (0.24 +/- 0.02 to 3.90 +/- 0.25). Implementation of optimal plasma sampling in persistently neutropenic rabbit infection models of disseminated candidiasis and pulmonary aspergillosis based on the Bayesian approach and model parameters from normal animals as priors revealed a significantly slower clearance (P < 0.05 for all dosage groups) with a trend toward higher AUC(0-24) values, higher plasma concentrations at the end of the dosing interval, and a smaller volume of distribution (P < 0.05 to 0.193 for the various comparisons among dosage groups). Pharmacodynamic modeling using the residual fungal tissue burden in the main target sites as the primary endpoint and C(max), AUC(0-24), time during the dosing interval of 24 h with plasma drug concentration equaling or exceeding the MIC or the minimum fungicidal concentration for the isolate, and tissue concentrations as pharmacodynamic parameters showed predictable pharmacokinetic-pharmacodynamic relationships in experimental disseminated candidiasis that fitted well with an inhibitory sigmoid maximum effect pharmacodynamic model (r(2), 0.492 to 0.819). However, no concentration-effect relationships were observed in experimental pulmonary aspergillosis using the residual fungal burden in lung tissue and survival as parameters of antifungal efficacy. Implementation of optimal plasma sampling in discriminative animal models of invasive fungal infections and pharmacodynamic modeling is a novel approach that holds promise of improving and accelerating our understanding of the action of antifungal compounds in vivo.


Subject(s)
Antifungal Agents/pharmacokinetics , Candidiasis/metabolism , Neutropenia/metabolism , Opportunistic Infections/metabolism , Peptides, Cyclic/pharmacokinetics , Anidulafungin , Animals , Antifungal Agents/blood , Antifungal Agents/pharmacology , Aspergillosis/metabolism , Disease Models, Animal , Echinocandins , Female , Lung Diseases, Fungal/metabolism , Peptides, Cyclic/blood , Peptides, Cyclic/pharmacology , Rabbits , Tissue Distribution
7.
J Bacteriol ; 183(18): 5414-25, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11514527

ABSTRACT

Escherichia coli isolates that were tolerant of incorporation of high proportions of 4-fluorotryptophan were evolved by serial growth. The resultant strain still preferred tryptophan for growth but showed improved growth relative to the parental strain on other tryptophan analogues. Evolved clones fully substituted fluorotryptophan for tryptophan in their proteomes within the limits of mass spectral and amino acid analyses. Of the genes sequenced, many genes were found to be unaltered in the evolved strain; however, three genes encoding enzymes involved in tryptophan uptake and utilization were altered: the aromatic amino acid permease (aroP) and tryptophanyl-tRNA synthetase (trpS) contained several amino acid substitutions, and the tyrosine repressor (tyrR) had a nonsense mutation. While kinetic analysis of the tryptophanyl-tRNA synthetase suggests discrimination against 4-fluorotryptophan, an analysis of the incorporation and growth patterns of the evolved bacteria suggest that other mutations also aid in the adaptation to the tryptophan analogue. These results suggest that the incorporation of unnatural amino acids into organismal proteomes may be possible but that extensive evolution may be required to reoptimize proteins and metabolism to accommodate such analogues.


Subject(s)
Amino Acid Transport Systems , Escherichia coli Proteins , Escherichia coli/growth & development , Escherichia coli/genetics , Mutation , Selection, Genetic , Tryptophan/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Carrier Proteins/genetics , Carrier Proteins/metabolism , Culture Media/chemistry , Escherichia coli/metabolism , Evolution, Molecular , Genes, Bacterial , Proteome , Repressor Proteins/genetics , Repressor Proteins/metabolism , Tryptophan/analogs & derivatives , Tryptophan-tRNA Ligase/genetics , Tryptophan-tRNA Ligase/metabolism
8.
Cytokine ; 15(2): 87-95, 2001 Jul 21.
Article in English | MEDLINE | ID: mdl-11500084

ABSTRACT

The in vivo and ex vivo effects of macrophage colony-stimulating factor (M-CSF) were studied in a profoundly neutropenic rabbit model in order to determine its potential to augment pulmonary host defence against Aspergillus. M-CSF (100-600 microg/kg/d) was administered prophylactically to neutropenic rabbits with pulmonary aspergillosis starting three days pre-inoculation and then throughout neutropenia. Rabbits receiving M-CSF had significantly increased survival (P=0.01) and decreased pulmonary injury, as measured by decreased pulmonary infarction (P=0.004), when compared with untreated controls. Microscopic studies demonstrated greater numbers of activated pulmonary alveolar macrophages (PAMs) in lung tissue of rabbits receiving M-CSF, in comparison to controls (P<0.001). PAMs harvested from rabbits treated with M-CSF had a significantly greater percent phagocytosis of Aspergillus fumigatus conidia than did PAMs from controls (P=0.04). These data indicate that prophylactic administration of M-CSF augments pulmonary host defence against A. fumigatus and suggest a potential role for this cytokine as adjunctive therapy in the treatment of pulmonary aspergillosis in the setting of profound neutropenia.


Subject(s)
Antifungal Agents/pharmacology , Aspergillosis/drug therapy , Lung Diseases, Fungal/drug therapy , Macrophage Colony-Stimulating Factor/pharmacology , Animals , Aspergillosis/immunology , Aspergillosis/pathology , Aspergillus fumigatus/drug effects , Female , Humans , Lung Diseases, Fungal/immunology , Lung Diseases, Fungal/pathology , Macrophages/immunology , Phagocytosis/drug effects , Phagocytosis/immunology , Pneumonia/drug therapy , Pneumonia/microbiology , Pneumonia/pathology , Pulmonary Alveoli/pathology , Pulmonary Embolism/drug therapy , Pulmonary Embolism/pathology , Rabbits , Recombinant Proteins , Survival Rate
9.
J Invest Surg ; 14(2): 109-20, 2001.
Article in English | MEDLINE | ID: mdl-11396618

ABSTRACT

Diminished tissue injury and shortened clinical recovery are benefits of using an endoscopic approach for patients needing operative procedure. In the course of developing an experimental model requiring procurement of topographically precise lung biopsy specimens, we sought to apply thoracoscopy as a research alternative to thoracotomy. In addition, we investigated the influence of thoracoscopy on postprocedure recovery practices using rabbits divided into four treatment groups. Rabbit groups 1 and 2 underwent thoracoscopy and lung biopsy while maintained by one-lung anesthesia. Additionally, group 2 had ketoprofen and bupivacaine HCl analgesics injected for treatment during postprocedure recovery. These two groups were compared to control rabbits in groups 3 and 4, which underwent inhalant anesthesia without thoracoscopy. Control group 3 also received the injection analgesic combination. During recovery, rabbit behavior was systematically assessed for evidence of pain. No behavior considered indicative of pain needing intervention was observed regardless of treatment group. Limited changes in plasma corticosterone, catecholamines, and prostaglandin E2 levels measured during recovery were difficult to associate with any treatment. Unexpectedly, significantly different mean corticosterone and catecholamines levels were detected in rabbits given the injection analgesic combination in the absence of thoracoscopic procedure, as compared to other treatment groups. The results highlight the importance of awareness that analgesic drug administration has the potential to alter homeostasis and affect interpretation of some study findings by its own guise. Correlation of the mean pain study results with plasma biochemical data supports preferential use of thoracoscopy as a refinement for limiting postprocedural pain in research models.


Subject(s)
Lung/surgery , Pain, Postoperative/prevention & control , Thoracoscopy , Anesthesia, Inhalation/methods , Animal Welfare , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Behavior, Animal , Biopsy/methods , Blood Gas Analysis , Bronchoscopy , Corticosterone/blood , Dinoprostone/blood , Disease Models, Animal , Female , Lung/pathology , Male , Norepinephrine/blood , Rabbits , Specific Pathogen-Free Organisms
10.
Antimicrob Agents Chemother ; 45(3): 857-69, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11181372

ABSTRACT

The antifungal efficacy, safety, and pharmacokinetics of posaconazole (SCH 56592) (POC) were investigated in treatment and prophylaxis of primary pulmonary aspergillosis due to Aspergillus fumigatus in persistently neutropenic rabbits. Antifungal therapy consisted of POC at 2, 6, and 20 mg/kg of body weight per os; itraconazole (ITC) at 2, 6, and 20 mg/kg per os; or amphotericin B (AMB) at 1 mg/kg intravenously. Rabbits treated with POC showed a significant improvement in survival and significant reductions in pulmonary infarct scores, total lung weights, numbers of pulmonary CFU per gram, numbers of computerized-tomography-monitored pulmonary lesions, and levels of galactomannan antigenemia. AMB and POC had comparable therapeutic efficacies by all parameters. By comparison, animals treated with ITC had no significant changes in outcome variables in comparison to those of untreated controls (UC). Rabbits receiving prophylactic POC at all dosages showed a significant reduction in infarct scores, total lung weights, and organism clearance from lung tissue in comparison to results for UC (P < 0.01). There was dosage-dependent microbiological clearance of A. fumigatus from lung tissue in response to POC. Serum creatinine levels were greater (P < 0.01) in AMB-treated animals than in UC and POC- or ITC-treated rabbits. There was no elevation of serum hepatic transaminase levels in POC- or ITC-treated rabbits. The pharmacokinetics of POC and ITC in plasma demonstrated dose dependency after multiple dosing. The 2-, 6-, and 20-mg/kg dosages of POC maintained plasma drug levels above the MICs for the entire 24-h dosing interval. In summary, POC at > or =6 mg/kg/day per os generated sustained concentrations in plasma of > or =1 microg/ml that were as effective in the treatment and prevention of invasive pulmonary aspergillosis as AMB at 1 mg/kg/day and more effective than cyclodextrin ITC at > or =6 mg/kg/day per os in persistently neutropenic rabbits.


Subject(s)
Antifungal Agents/therapeutic use , Aspergillosis/drug therapy , Lung Diseases, Fungal/drug therapy , Mannans/metabolism , Triazoles/therapeutic use , Animals , Antibiotic Prophylaxis , Antifungal Agents/adverse effects , Antifungal Agents/pharmacokinetics , Aspergillosis/immunology , Aspergillosis/metabolism , Aspergillosis/prevention & control , Aspergillus fumigatus/drug effects , Disease Models, Animal , Female , Galactose/analogs & derivatives , Itraconazole/adverse effects , Itraconazole/pharmacokinetics , Itraconazole/therapeutic use , Lung Diseases, Fungal/immunology , Lung Diseases, Fungal/metabolism , Lung Diseases, Fungal/prevention & control , Mannans/immunology , Neutropenia/etiology , Rabbits , Treatment Outcome , Triazoles/adverse effects , Triazoles/pharmacokinetics
11.
Antimicrob Agents Chemother ; 45(2): 471-9, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11158743

ABSTRACT

V-echinocandin (VER-002; LY303366) is a semisynthetic derivative of echinocandin B and a potent inhibitor of fungal (1, 3)-beta-D-glucan synthase. We studied the antifungal efficacy, the concentrations in saliva and tissue, and the safety of VER-002 at escalating dosages against experimental oropharyngeal and esophageal candidiasis caused by fluconazole-resistant Candida albicans in immunocompromised rabbits. Study groups consisted of untreated controls, animals treated with VER-002 at 1, 2.5, and 5 mg/kg of body weight/day intravenously (i.v.), animals treated with fluconazole at 2 mg/kg/day i.v., or animals treated with amphotericin B at 0.3 mg/kg/day. VER-002-treated animals showed a significant dosage-dependent clearance of C. albicans from the tongue, oropharynx, esophagus, stomach, and duodenum in comparison to that for untreated controls. VER-002 also was superior to amphotericin B and fluconazole in clearing the organism from all sites studied. These in vivo findings are consistent with the results of in vitro time-kill assays, which demonstrated that VER-002 has concentration-dependent fungicidal activity. Esophageal tissue VER-002 concentrations were dosage proportional and exceeded the MIC at all dosages. Echinocandin concentrations in saliva were greater than or equal to the MICs at all dosages. There was no elevation of serum hepatic transaminase, alkaline phosphatase, bilirubin, potassium, or creatinine levels in VER-002-treated rabbits. In summary, the echinocandin VER-002 was well tolerated, penetrated the esophagus and salivary glands, and demonstrated dosage-dependent antifungal activity against fluconazole-resistant esophageal candidiasis in immunocompromised rabbits.


Subject(s)
Antifungal Agents/therapeutic use , Candidiasis/drug therapy , Fluconazole/pharmacology , Peptides, Cyclic/therapeutic use , Amphotericin B/therapeutic use , Anidulafungin , Animals , Antifungal Agents/administration & dosage , Antifungal Agents/pharmacokinetics , Candidiasis/microbiology , Candidiasis/pathology , Candidiasis, Oral/drug therapy , Candidiasis, Oral/microbiology , Candidiasis, Oral/pathology , Drug Resistance, Microbial , Echinocandins , Esophageal Diseases/drug therapy , Esophageal Diseases/microbiology , Esophageal Diseases/pathology , Esophagus/metabolism , Female , Immunosuppression Therapy , Peptides, Cyclic/administration & dosage , Peptides, Cyclic/pharmacokinetics , Pharyngeal Diseases/drug therapy , Pharyngeal Diseases/microbiology , Pharyngeal Diseases/pathology , Rabbits , Saliva/microbiology
12.
Comp Med ; 51(5): 430-5, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11924803

ABSTRACT

PURPOSE: To investigate the potential activity of cyclosporin A (CsA) to induce mammary hyperplasia in New Zealand White (NZW) rabbits. METHODS: Female NZW rabbits were used throughout experiments. To simulate the conditions of immunosuppression, CsA (10 mg/kg of body weight/d) was administered intravenously on a daily basis for 14 days and methylprednisolone (5 mg/kg/d) was administered on the first two days. The CsA (10 mg/kg/d) also was administered without methylprednisolone for 14 days to another cohort of rabbits. Mammary tissue of each rabbit was palpated and serially measured during this treatment period. The CsA was discontinued, and rabbits were monitored for 14 more days during the washout period. Sequential plasma concentrations of prolactin, 17beta-estradiol, and progesterone in each blood sample were determined by use of radioimmunoassay. RESULTS: All NZW rabbits treated with CsA and methylprednisolone for immunosuppression consistently developed striking mammary tissue hyperplasia. At the end of treatment with CsA and methylprednisolone, mammary glands had extensive changes consistent with actively lactating glands. Similar but less extensive hyperplasia developed in response to CsA alone. Plasma concentration of prolactin increased during treatment and decreased during the washout period. Plasma concentration of 17beta-estradiol increased during treatment and continued to increase during the washout period. Plasma progesterone concentration decreased at the end of treatment. On discontinuation of CsA, mammary hyperplasia regressed. CONCLUSIONS: Cyclosporine A, with or without methylprednisolone, induces mammary hyperplasia and hyperprolactinemia in NZW rabbits. This rabbit model may be a reliable in vivo system by which to study immunosuppressant-induced structural and functional changes of mammary glands similar to those observed in humans.


Subject(s)
Cyclosporine/toxicity , Hyperprolactinemia/chemically induced , Immunosuppressive Agents/toxicity , Mammary Glands, Animal/drug effects , Animals , Disease Models, Animal , Estradiol/blood , Female , Humans , Hyperplasia , Hyperprolactinemia/blood , Mammary Glands, Animal/pathology , Methylprednisolone/toxicity , Progesterone/blood , Prolactin/blood , Rabbits
13.
Alcohol Clin Exp Res ; 25(12): 1758-65, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11781509

ABSTRACT

BACKGROUND: Alcohol amblyopia is a rare neuropathy characterized by the development of blurred vision and a reduction in visual acuity. Further diagnostic details of this condition have shown abnormalities in the electroretinogram (ERG) that include an increase in implicit times in the a- and b-waves and a depression of b-wave amplitude. METHODS: Periodically, the ERGs and the fatty acyl composition of nervous tissue were analyzed from alcohol-consuming rhesus monkeys (Macaca mulatta) (mean consumption 2.6 g kg/day over a 5-year period) and controls that were maintained on a nutritionally sufficient diet that had low, yet adequate, amounts of linoleic acid but very low alpha-linolenic acid. RESULTS: Animals consuming alcohol had increased a- and b-wave implicit times and decreased b-wave amplitudes in their electroretinograms compared with those of the dietary control group at 2.5 and 5 years. The fatty acyl composition of brain specimens obtained by surgical biopsy at baseline, 2.5 years, and 5 years demonstrated that docosahexaenoic acid (DHA) had decreased in both groups of animals compared with baseline values. In the brains of the alcohol-treated animals, DHA was even further decreased (2.5 years: -20%; 5 years: -33%) compared with the diet controls. In the retinas of the alcohol-consuming animals at 5 years, there was a similar decrease in DHA (-35%) compared with controls. Generally, the n-6 fatty acid, docosapentaenoic acid (DPAn-6) increased in these tissues, apparently compensating for the loss of DHA. CONCLUSIONS: A reciprocal change in the DHA/DPAn-6 ratio is known to be associated with abnormal electroretinograms in a number of species. Thus, a marginal intake of n-3 fatty acids in some alcohol abusers may, in part, be responsible for the biochemical changes that underlie the diminished retinal function associated with the visual abnormalities observed in alcohol-amblyopic patients.


Subject(s)
Animal Nutritional Physiological Phenomena , Brain/metabolism , Docosahexaenoic Acids/metabolism , Electroretinography , Ethanol/administration & dosage , Fatty Acids, Omega-3/administration & dosage , Alcoholism/complications , Animals , Brain Chemistry , Fatty Acids/analysis , Fatty Acids, Omega-3/physiology , Macaca mulatta , Male , Retina/chemistry , Vision Disorders/etiology
14.
Antimicrob Agents Chemother ; 44(8): 2068-76, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10898677

ABSTRACT

Amphotericin B lipid complex (ABLC) was recently approved by the Food and Drug Administration for treatment of patients with invasive fungal infections who are intolerant of or refractory to conventional amphotericin B therapy. Little is known, however, about the pharmacokinetics of this new antifungal compound. We therefore investigated the pharmacokinetics of ABLC in comparison with those of conventional desoxycholate amphotericin B (DAmB) in rabbits. The pharmacokinetics of DAmB in a rabbit model were similar to those previously reported in humans. The pharmacokinetics of ABLC differed substantially from those of DAmB. Plasma amphotericin B levels following ABLC administration were 10 times lower than those following administration of an equal dosage of DAmB. The levels of ABLC in whole blood were approximately 40 times greater than those in plasma. The ABLC model differed from the DAmB model by (i) a dose- and time-dependent uptake and return between the plasma compartment and apparent cellular components of the blood-sediment compartment and (ii) time-dependent tissue uptake and return to plasma from serially connected compartments. Following infusion of ABLC, there was a nonlinear uptake into the apparent cellular components of the blood-sediment compartment. This uptake was related to the reciprocal of the integral of the total amount of drug infused (i.e., the more drug infused the greater the fractional uptake between 0.5 and 5 mg/kg of body weight for ABLC). The transfer of drug from plasma to the cellular components of the blood-sediment compartment resulted in initial uptake followed by rapid redistribution back to the plasma. The study describes a detailed model of the pharmacokinetics of ABLC and characterizes a potential role of the cellular components of the blood-sediment compartment in the distribution of this new antifungal compound in tissue.


Subject(s)
Amphotericin B/pharmacokinetics , Antifungal Agents/pharmacokinetics , Amphotericin B/administration & dosage , Animals , Antifungal Agents/administration & dosage , Chemistry, Pharmaceutical , Dose-Response Relationship, Drug , Female , Lipids/chemistry , Models, Biological , Rabbits , Reproducibility of Results
15.
J Infect Dis ; 182(1): 274-82, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10882607

ABSTRACT

The central nervous system (CNS) distribution and antifungal efficacy of all 4 approved formulations of amphotericin B (AmB) were investigated in a rabbit model of hematogenous Candida albicans meningoencephalitis. Treatment with AmB deoxycholate (1 mg/kg/day) or liposomal AmB (5 mg/kg/day) yielded the highest peak plasma concentration (C(max)), area under concentration versus time curve from zero to 24 h (AUC(0-24)), and time during dosing level tau Ttau>minimum inhibitory complex (MIC) values and led to complete eradication of C. albicans from brain tissue (P<.05 vs. untreated controls). By comparison, AmB colloidal dispersion and AmB lipid complex (5 mg/kg/day each) were only partially effective (not significant vs. untreated controls). There was a strong correlation of C(max), AUC(0-24), C(max)/MIC, AUC(0-24)/MIC, and Ttau>MIC with clearance of C. albicans from brain tissue (P

Subject(s)
Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , Candida albicans/drug effects , Candidiasis/drug therapy , Central Nervous System Fungal Infections/drug therapy , Amphotericin B/administration & dosage , Amphotericin B/blood , Animals , Antifungal Agents/administration & dosage , Antifungal Agents/blood , Candidiasis/blood , Candidiasis/metabolism , Central Nervous System Fungal Infections/blood , Central Nervous System Fungal Infections/microbiology , Chemistry, Pharmaceutical , Disease Models, Animal , Drug Delivery Systems , Female , Lipids/chemistry , Microbial Sensitivity Tests , Rabbits , Treatment Outcome
16.
J Clin Microbiol ; 38(6): 2369-73, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10835005

ABSTRACT

Oropharyngeal and esophageal candidiasis (OPEC) is a frequent opportunistic mycosis in immunocompromised patients. Azole-resistant OPEC is a refractory form of this infection occurring particularly in human immunodeficiency virus (HIV)-infected patients. The procedures developed by the Antifungal Subcommittee of the National Committee for Clinical Laboratory Standards (NCCLS) are an important advance in standardization of in vitro antifungal susceptibility methodology. In order to further understand the relationship between NCCLS methodology and antifungal therapeutic response, we studied the potential correlation between in vitro susceptibility to fluconazole and in vivo response in a rabbit model of fluconazole-resistant OPEC. MICs of fluconazole were determined by NCCLS methods. Three fluconazole-susceptible (FS) (MIC, /=64 microgram/ml) isolates of Candida albicans from prospectively monitored HIV-infected children with OPEC were studied. FR isolates were recovered from children with severe OPEC refractory to fluconazole, and FS isolates were recovered from those with mucosal candidiasis responsive to fluconazole. Fluconazole at 2 mg/kg of body weight/day was administered to infected animals for 7 days. The concentrations of fluconazole in plasma were maintained above the MICs for FS isolates throughout the dosing interval. Fluconazole concentrations in the esophagus were greater than or equal to those in plasma. Rabbits infected with FS isolates and treated with fluconazole had significant reductions in oral mucosal quantitative cultures (P < 0.001) and tissue burden of C. albicans in tongue, soft palate, and esophagus (P < 0.001). In comparison, rabbits infected with FR isolates were unresponsive to fluconazole and had no reduction in oral mucosal quantitative cultures or tissue burden of C. albicans versus untreated controls. We conclude that there is a strong correlation between in vitro fluconazole susceptibility by NCCLS methods and in vivo response to fluconazole therapy of OPEC due to C. albicans.


Subject(s)
Candidiasis, Oral/drug therapy , Candidiasis/drug therapy , Esophageal Diseases/drug therapy , Fluconazole/pharmacology , Microbial Sensitivity Tests/methods , Pharyngeal Diseases/drug therapy , Animals , Child , Colony Count, Microbial , Disease Models, Animal , Drug Resistance, Microbial , Duodenum/microbiology , Female , Humans , Immunosuppression Therapy , Microbial Sensitivity Tests/standards , Mouth/microbiology , Rabbits , Stomach/microbiology
17.
Nat Biotechnol ; 18(3): 289-95, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10700143

ABSTRACT

Hemophilia A and B coagulation defects, which are caused by deficiencies of Factor VIII and Factor IX, respectively, can be bypassed by administration of recombinant Factor VIIa. However, the short half-life of recombinant Factor VIIa in vivo negates its routine clinical use. We report here an in vivo method for the continuous generation of Factor VIIa. The method depends on the implantation of a porous chamber that contains Factor Xa or XIIa, and continuously generates Factor VIIa bypass activity from the subject's own Factor VII, which enters the chamber by diffusion. Once inside, the Factor VII is cleaved to Factor VIIa by the immobilized Factor Xa or XIIa. The newly created Factor VIIa diffuses out of the chamber and back into the circulation, where it can bypass the deficient Factors VIII or IX, and enable coagulation to occur. In vitro, this method generates sufficient Factor VIIa to substantially correct Factor VIII-deficient plasma when assessed by the classical aPTT coagulation assay. In vivo, a Factor XIIa peritoneal implant generates bypass activity for up to one month when tested in rhesus monkeys. Implantation of such a chamber in a patient with hemophilia A or B could eventually provide a viable alternative to replacement therapies using exogenous coagulation factors.


Subject(s)
Coagulants/administration & dosage , Factor XIIa/administration & dosage , Hemophilia A/drug therapy , Recombinant Proteins/administration & dosage , Animals , Coagulants/therapeutic use , Factor IX/metabolism , Factor VIII/metabolism , Factor XIIa/metabolism , Factor XIIa/pharmacology , Factor XIIa/therapeutic use , Fibrinogen/metabolism , Guinea Pigs , Infusion Pumps, Implantable , Macaca mulatta , Male , Peritoneum , Recombinant Proteins/metabolism , Recombinant Proteins/pharmacology , Recombinant Proteins/therapeutic use , Time Factors
18.
Cancer Chemother Pharmacol ; 45(3): 259-64, 2000.
Article in English | MEDLINE | ID: mdl-10663645

ABSTRACT

PURPOSE: Intrathecal methotrexate achieves high concentrations in cerebrospinal fluid (CSF), but drug distribution throughout the subarachnoid space after an intralumbar dose is limited. The objective of this study was to quantify methotrexate distribution in CSF after intraventricular and intravenous administration and to identify factors that influence CSF distribution. METHODS: Nonhuman primates (Macaca mulatta) with permanently implanted catheters in the lateral and fourth ventricles received methotrexate by bolus injection (0.5 mg) and infusion (0.05 to 0.5 mg/day over 24 to 168 h) into the lateral ventricle, as well as intravenous infusions. CSF was sampled from the lumbar space, fourth ventricle and the subarachnoid space at the vertex. Methotrexate in CSF and plasma was measured with the dihydrofolate reductase inhibition assay. RESULTS: After bolus intraventricular injection, methotrexate exposure in lumbar CSF ranged from 11% to 69% of that achieved in the fourth ventricle. During continuous intraventricular infusions, methotrexate steady-state concentrations (C(ss)) in lumbar CSF and CSF from the vertex were only 20% to 25% of the ventricular CSF C(ss). The dose, duration of infusion, and infusate volume did not influence drug distribution to the lumbar CSF, but probenicid increased the lumbar to ventricular C(ss) ratio, suggesting the involvement of a probenicid-sensitive transport pump in the efflux of MTX from the CSF. During the intravenous infusions, the ventricular methotrexate C(ss) was lower than the lumbar C(ss) and the C(ss) in CSF from the vertex. CONCLUSION: Methotrexate CSF distribution after intraventricular injection was uneven, and at steady-state CSF methotrexate concentrations were lower at sites that were more distant from the injection site.


Subject(s)
Antimetabolites, Antineoplastic/cerebrospinal fluid , Methotrexate/cerebrospinal fluid , Subarachnoid Space/metabolism , Animals , Antimetabolites, Antineoplastic/pharmacokinetics , Brain/drug effects , Brain/metabolism , Cerebral Ventricles/drug effects , Dose-Response Relationship, Drug , Infusions, Intravenous , Infusions, Parenteral , Injections, Intraventricular , Macaca mulatta , Male , Metabolic Clearance Rate , Methotrexate/pharmacokinetics , Probenecid/pharmacology , Uricosuric Agents/pharmacology
19.
J Forensic Sci ; 44(6): 1243-57, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10582363

ABSTRACT

The Gene Print PowerPlex 1.1/Amelogenin and FFFL Fluorescent STR Systems have been validated following the recommendations presented by the Technical Working Group on DNA Analysis Methods (TWGDAM). The PowerPlex 1.1/Amelogenin System supports simultaneous amplification of eight short tandem repeat loci and the Amelogenin gender identification marker. The loci D16S539, D7S820, D13S317, and D5S818 are labeled with fluorescein (FL) while the loci CSF1PO, TP0X, TH01, vWA and Amelogenin are labeled with carboxy-tetramethylrhodamine (TMR). The FFFL Multiplex System is composed of the loci F13A01, FESFPS, F13B, and LPL, each labeled with fluorescein. We have observed no overlap of alleles across loci labeled with an individual fluorescent dye. Samples of each system were amplified and labeled in a single reaction, separated by electrophoresis through a denaturing polyacrylamide gel, and amplified alleles detected using a Hitachi FMBIO Fluorescent Scanner. Alterations from the standard amplification protocols in cycle number and annealing temperature generally produced excellent results. In experiments testing sensitivity as little as 0.2 ng of DNA template could be detected. As expected, different body fluids from the same individuals generated identical DNA profile results. Template DNA derived from blood-strains deposited on a variety of matrix supports displayed robust amplification except for material derived from deposits on wood and Japanese orchid leaves. Mixtures of DNA templates could be interpreted with the minor component present in as little as ten percent of the total sample. Monoplex and multiplex amplifications produced identical amplified allele patterns, indicating that STR multiplex systems save template and increase efficiency in the amplification procedure without loss of quality. Analyses of genotype frequencies in African-American, Caucasian-American and Hispanic-American populations using all twelve loci were used to determine matching probabilities smaller than 1 in 1.14 x 10(8) and 1 in 2658 for the PowerPlex 1.1 and the FFFL Multiplex Systems, respectively. The matching probability achieved with the two systems combined is smaller than 1 in 3.03 x 10(11). The independence of alleles within loci was generally demonstrated by applying the exact test to demonstrate Hardy-Weinberg Equilibrium. All of the studies performed indicate that the PowerPlex 1.1/Amelogenin and FFFL Multiplex Systems are powerful, robust, and reliable investigative tools that can be used in the analysis of forensic samples.


Subject(s)
DNA Fingerprinting/methods , Polymerase Chain Reaction/methods , Tandem Repeat Sequences/genetics , Forensic Medicine/methods , Humans , Reproducibility of Results , Sensitivity and Specificity
20.
Antimicrob Agents Chemother ; 43(10): 2463-7, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10508025

ABSTRACT

The activity of liposomal nystatin (L-Nys) against subacute disseminated candidiasis was investigated in persistently neutropenic rabbits. Antifungal therapy was administered for 10 days starting 24 h after intravenous inoculation of 10(3) blastoconidia of Candida albicans. Responses to treatment were assessed by the quantitative clearance of the organism from blood and tissues. Treatments consisted of L-Nys at dosages of 2 and 4 mg/kg of body weight/day (L-Nys2 and L-Nys4, respectively) amphotericin B deoxycholate at 1 mg/kg/day (D-AmB), and fluconazole at 10 mg/kg/day (Flu). All treatments were given intravenously once daily. Compared to the results for untreated but infected control animals, treatment with L-Nys2, L-Nys4, D-AmB, and Flu resulted in a significant clearance of the residual burden of C. albicans from the kidney, liver, spleen, lung, and brain (P < 0.0001 by analysis of variance). When the proportion of animals infected at at least one of the five tissue sites studied was evaluated, a dose-dependent response to treatment with L-Nys was found (P < 0.05). Compared to D-AmB-treated rabbits, mean serum creatinine and blood urea nitrogen levels at the end of therapy were significantly lower in animals treated with L-Nys2 (P < 0.001) and L-Nys4 (P < 0.001 and P < 0.01, respectively). L-Nys was less nephrotoxic than conventional amphotericin B and had dose-dependent activity comparable to that of amphotericin B for the early treatment of subacute disseminated candidiasis in persistently neutropenic rabbits.


Subject(s)
Antifungal Agents/therapeutic use , Candidiasis/drug therapy , Nystatin/therapeutic use , Amphotericin B/therapeutic use , Animals , Antifungal Agents/administration & dosage , Antifungal Agents/toxicity , Candidiasis/etiology , Disease Models, Animal , Drug Carriers , Fluconazole/therapeutic use , Liposomes , Nystatin/administration & dosage , Nystatin/toxicity , Rabbits , Treatment Outcome
SELECTION OF CITATIONS
SEARCH DETAIL
...