The Effect of Glutathione on Itraconazole‐Associated Hepatocyte Toxicity in an
            In Vitro
            Canine Model

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

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The Development of Homologous (Canine/Anti-Canine) Antibodies in Dogs with Haemophilia A (Factor VIII Deficiency): A Ten-Year Longitudinal Study

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651541 ◽

1993 ◽

Vol 69 (01) ◽

pp. 021-024 ◽

Cited By ~ 20

Author(s):

Shawn Tinlin ◽

Sandra Webster ◽

Alan R Giles

Keyword(s):

Factor Viii ◽

Canine Model ◽

Significant Inhibition ◽

Human Condition ◽

Haemophilia A ◽

Variable Expression ◽

The Family ◽

Over Time

SummaryThe development of inhibitors to factor VIII in patients with haemophilia A remains as a serious complication of replacement therapy. An apparently analogous condition has been described in a canine model of haemophilia A (Giles et al., Blood 1984; 63:451). These animals and their relatives have now been followed for 10 years. The observation that the propensity for inhibitor development was not related to the ancestral factor VIII gene has been confirmed by the demonstration of vertical transmission through three generations of the segment of the family related to a normal (non-carrier) female that was introduced for breeding purposes. Haemophilic animals unrelated to this animal have not developed functionally significant factor VIII inhibitors despite intensive factor VIII replacement. Two animals have shown occasional laboratory evidence of factor VIII inhibition but this has not been translated into clinical significant inhibition in vivo as assessed by clinical response and F.VIII recovery and survival characteristics. Substantial heterogeneity of inhibitor expression both in vitro and in vivo has been observed between animals and in individual animals over time. Spontaneous loss of inhibitors has been observed without any therapies designed to induce tolerance, etc., being instituted. There is also phenotypic evidence of polyclonality of the immune response with variable expression over time in a given animal. These observations may have relevance to the human condition both in determining the pathogenetic factors involved in this condition and in highlighting the heterogeneity of its expression which suggests the need for caution in the interpretation of the outcome of interventions designed to modulate inhibitor activity.

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Electrospun PLGA and PLGA/gelatin scaffolds for tubularized urethral replacement: Studies in vitro and in vivo

Journal of Biomaterials Applications ◽

10.1177/08853282211030904 ◽

2021 ◽

pp. 088532822110309

Author(s):

Jinhua Hu ◽

Bin Ai ◽

Shibo Zhu ◽

Zhen Wang ◽

Huimin Xia ◽

...

Keyword(s):

Tensile Deformation ◽

Canine Model ◽

Urothelial Cells ◽

Acellular Matrix ◽

Urethral Strictures ◽

Acid Copolymer ◽

Hematoxylin Eosin ◽

Collagen Tissue

To investigate the biocompatibility of polylactic acid-glycolic acid copolymer (PLGA) and PLGA/gelatin scaffolds and their suitability for tubular urethral replacement in a canine model. PLGA and PLGA/gelatin scaffolds was constructed by electrospinning. Microstructural differences between the scaffolds was examined by Scanning electron microscopy (SEM) followed by mechanical properties testing. Biocompatibility of the material was evaluated using SEM 4, 8, 12 and 72 h after PLGA and PLGA/gelatin scaffolds co-culture with urothelial cells. And confocal analysis was also used to showed the cell adhesive and growth at 12 h. Approximately 2 cm of the anterior urethra of twelve dogs were removed and replaced with a scaffold. After the surgery for 1 month performed urethrography and for 3 month perform hematoxylin–eosin (H&E) and Masson. The results indicated that PLGA and PLGA/gelatin scaffolds had a void microfilament structure, similar to that of normal acellular matrix tissue. And the tensile strength was decreased whereas the tensile deformation and suture retention strength was increased in PLGA/gelatin scaffolds compared to that in PLGA scaffolds Urothelial cells grew well on both scaffolds. Postoperatively, animals recovered well and urinated spontaneously. However, urethrography showed varying degrees of urethral strictures in the reconstructed urethras. H&E and Masson showed that multilayer urothelial cells were formed in both the proximal and distal segments of the reconstructed urethras but without continuity. There was a small amount of smooth muscle and blood vessels under the epithelium, but regenerative urothelial cells at the midpoint of the reconstructed segment did not continue. Lots of lymphocyte infiltration was observed under the epithelium, some collagen tissue was deposited under the neo-urethral epithelium were observed. In conclusion, PLGA and PLGA/gelatin scaffolds are not suitable for tubularized urethral replacement in the canine model.

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Evidence of the role of hemolysis in experimental cerebral vasospasm

Journal of Neurosurgery ◽

10.3171/jns.1990.72.5.0775 ◽

1990 ◽

Vol 72 (5) ◽

pp. 775-781 ◽

Cited By ~ 44

Author(s):

John W. Peterson ◽

Lawrence Roussos ◽

Byung-Duk Kwun ◽

John D. Hackett ◽

Christopher J. Owen ◽

...

Keyword(s):

Cerebral Vasospasm ◽

Ex Vivo ◽

Platelet Rich Plasma ◽

Canine Model ◽

Initial Reaction ◽

Basal Cistern ◽

Content Type ◽

Vascular Reaction ◽

Erythrocyte Lysis

✓ The short-term (≤ 72-hour) reaction to subarachnoid injections of various blood components was determined in a canine model of cerebral vasospasm. Platelet-rich plasma (PRP) formed durable clots in the basal cistern surrounding the basilar artery and provoked no vascular reaction in 72 hours or more. Freshly isolated autologous erythrocytes resuspended in PRP likewise provoked no vasoconstriction in 72 hours, although a second injection of fresh erythrocytes in PRP induced significant reaction, as in the conventional “double subarachnoid hemorrhage (SAH)” canine model. Hemolysate of fresh erythrocytes led to a severe immediate vascular reaction after introduction into the basal cistern using PRP as the carrier/clotting medium, as did the injection of intact erythrocytes incubated ex vivo for 72 hours. Resolution of the initial reaction was rapid for hemolysate, but slow and (depending on hematocrit) incomplete for intact “aged” erythrocytes. In vitro measurements of erythrocyte lysis in these media and histological examination indicate that the production of erythrocyte lysate was responsible for the vascular reaction observed, suggesting that the rate of lysis of erythrocytes in the subarachnoid clot is a major factor in the genesis of vasospasm after SAH.

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Ultraviolet irradiation of blood prevents transfusion-induced sensitization and marrow graft rejection in dogs

Blood ◽

10.1182/blood.v67.2.537.537 ◽

1986 ◽

Vol 67 (2) ◽

pp. 537-539 ◽

Cited By ~ 39

Author(s):

HJ Deeg ◽

J Aprile ◽

TC Graham ◽

FR Appelbaum ◽

R Storb

Keyword(s):

Ultraviolet Irradiation ◽

Graft Rejection ◽

Uv Light ◽

Canine Model ◽

Donor Blood ◽

Histocompatibility Antigens ◽

Marrow Graft ◽

Accessory Cells ◽

In Vitro Exposure

Abstract In a canine model using DLA-identical littermate pairs, we have shown that a regimen of three transfusions of donor blood given 24, 17, and 10 days before transplant uniformly leads to marrow graft rejection, presumably due to sensitization to minor (non-DLA) histocompatibility antigens. Untransfused dogs uniformly achieve sustained engraftment. In the present study, we investigated whether the exposure of blood to ultraviolet (UV) light (220–300 nm) prior to transfusion prevented sensitization of the recipient and allowed for successful marrow engraftment. Ten dogs were each given three pretransplant transfusions from the marrow donor. Each transfusion consisted of 50 mL of whole blood exposed in vitro to UV light for a total of 1.35 J/cm2. All ten dogs achieved engraftment. In contrast, all four dogs that had received sham-exposed transfusions rejected their grafts. In vitro studies revealed that although cell viability was not affected, leukocytes contained in UV-exposed blood were unable to function as stimulator cells in mixed leukocyte cultures or as accessory cells in mitogen- stimulated cultures. These data are consistent with the hypothesis that accessory cells are involved in transfusion-induced sensitization. We conclude that in vitro exposure of blood to UV light before transfusion prevents sensitization and allows for subsequent marrow engraftment.

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FACTOR IX CONCENTRATES ARE THROMBOGENIC AT HIGH DOSES IN DOGS

10.1055/s-0038-1644069 ◽

1987 ◽

Author(s):

J Ferguson ◽

J Dawes ◽

C V Prowse ◽

P R Foster ◽

P A Feldman ◽

...

Keyword(s):

Platelet Count ◽

Fibrinogen Level ◽

Canine Model ◽

Factor Ix ◽

In Vitro Tests ◽

Fibrinopeptide A ◽

Blood Products ◽

Elevated Plasma ◽

High Doses

A canine model has recently been established to assess the potential thrombogenicity of intravenously infused blood products. Elevated plasma levels of fibrinopeptide A (FpA) were identified as the most sensitive indicator of a thrombogenic response, and this was the only parameter to change significantly when issued batches of factor IX (II + X) concentrate were infused at a dose of 100 iu/kg. After infusion of 200 iu/kg, however, plasma FpA concentrations and FDP titres rose, the APTT was prolonged, and the platelet count and fibrinogen level fell. At this dose, therefore, FIX concentrates which were not identified by in vitro tests as potentially thrombogenic induced a response when infused into dogs.A batch of FIX concentrate which failed the criteria for in vitro thrombogenicity and was therefore not issued for routine use was infused at 100 iu/kg. Plasma FpA levels rose as did the FDP titre, and fibrinogen concentrations fell, but the APTT was only slightly prolonged. The thrombogenic response to 200 iu/kg of issued FIX concentrate was at least as severe as that following infusion of 100 iu/kg of this rejected batch.Thus, there is a threshold dose of FIX concentrate above which a severe thrombogenic response can ensue, and the current in vitro tests may not be a reliable indicator of potential thrombogenicity when FIX concentrates are infused at high doses. This should be taken into account when administering unusually high doses, particularly to patients who may have reduced levels of circulating protease inhibitors.

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Lubricin Surface Modification Improves Extrasynovial Tendon Gliding in a Canine Model in Vitro

The Journal of Bone and Joint Surgery (American) ◽

10.2106/jbjs.g.00045 ◽

2008 ◽

Vol 90 (1) ◽

pp. 129-135 ◽

Cited By ~ 36

Author(s):

Manabu Taguchi ◽

Yu-Long Sun ◽

Chunfeng Zhao ◽

Mark E Zobitz ◽

Chung-Ja Cha ◽

...

Keyword(s):

Surface Modification ◽

Canine Model

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Effects of Cytochrome P450 Inhibitors on Itraconazole and Fluconazole Induced Cytotoxicity in Hepatocytes

Journal of Toxicology ◽

10.1155/2009/912320 ◽

2009 ◽

Vol 2009 ◽

pp. 1-7 ◽

Cited By ~ 11

Author(s):

Nhareet Somchit ◽

Chong Sock Ngee ◽

Azhar Yaakob ◽

Zuraini Ahmad ◽

Zainul Amiruddin Zakaria

Keyword(s):

Cytochrome P450 ◽

Liver Perfusion ◽

Antifungal Drugs ◽

Female Rats ◽

Atp Levels ◽

P450 Inhibitors ◽

Hepatocyte Toxicity

Itraconazole and fluconazole have been reported to induce hepatotoxicity in patients. The present study was designed to investigate the role of cytochrome P450 inhibitors, SKF 525A, and curcumin pretreatment on the cytotoxicity of antifungal drugs fluconazole and itraconazole. For 3 consecutive days, female rats were administered daily SKF 525A or curcumin (5 and 25 mg/kg). Control rats received an equivalent amount of dosed vehicle. The animals were anaesthetized 24 hours after receiving the last dose for liver perfusion. Hepatocytes were then exposed to various concentrations of antifungal drugs. In vitro incubation of hepatocytes with itraconazole revealed significantly lower viability when compared to fluconazole as assessed by lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase activities. The cytotoxicity of itraconazole was enhanced when incubated with hepatocytes pretreated with SKF 525A. SKF 525A had no effects on the cytotoxicity of fluconazole. Curcumin failed to either increase or decrease the cytotoxicity of both antifungal drugs. ATP levels also showed significant decrease in both itraconazole and fluconazole incubated hepatocytes. However, SKF 525A pretreated hepatocytes had significantly lower ATP levels after itraconazole incubations. Collectively, these results confirm the involvement of cytochrome P450 in the cytoprotection in itraconazole induced hepatocyte toxicity. Differences of the effects of SKF 525A on the cytotoxicity induced by itraconazole and fluconazole may be due to the differences on the metabolism of each antifungal drug in vivo.

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Alterations in endothelium-dependent responsiveness of the canine basilar artery after subarachnoid hemorrhage

Journal of Neurosurgery ◽

10.3171/jns.1988.69.2.0239 ◽

1988 ◽

Vol 69 (2) ◽

pp. 239-246 ◽

Cited By ~ 150

Author(s):

Phyo Kim ◽

Thoralf M. Sundt ◽

Paul M. Vanhoutte

Keyword(s):

Subarachnoid Hemorrhage ◽

Basilar Artery ◽

Calcium Ionophore ◽

Adenosine Diphosphate ◽

Canine Model ◽

Calcium Ionophore A23187 ◽

Ionophore A23187 ◽

Content Type ◽

Endothelium Dependent Relaxation

✓ To investigate the alteration of endothelium-dependent responses in chronic vasospasm after subarachnoid hemorrhage (SAH), experiments were carried out in the double-hemorrhage canine model. After the presence of vasospasm was confirmed by cerebral angiography on Days 0 and 7, pharmacological studies on the basilar artery were conducted in vitro on Day 8. In the SAH group, endothelium-dependent relaxation was abolished in response to arginine vasopressin and was significantly reduced in response to thrombin. Endothelium-independent relaxation in the SAH group was preserved in response to papaverine and was minimally reduced in response to sodium nitroprusside. Endothelium-dependent contraction in response to arachidonic acid, acetylcholine, the calcium ionophore A23187, adenosine diphosphate, mechanical stretching, and hypoxia persisted in the SAH group. The maximal contraction to KCl and uridine triphosphate, which is endothelium-independent, was diminished in the SAH group, but no changes in sensitivity were noted in the concentration-response relationships. A significant correlation was observed between the degree of vasospasm determined angiographically and the loss of endothelium-dependent relaxation. The loss of endothelium-dependent relaxation and the persistence of endothelium-dependent contraction suggest that the deterioration in the endothelium-dependent responses may be an important component in the pathogenesis of cerebral vasospasm.

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Xanthine oxidase mediates cyclic flow variations in a canine model of coronary arterial thrombosis

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1996.270.6.h1993 ◽

1996 ◽

Vol 270 (6) ◽

pp. H1993-H1999 ◽

Cited By ~ 1

Author(s):

K. Kuwano ◽

H. Ikeda ◽

T. Oda ◽

H. Nakayama ◽

Y. Koga ◽

...

Keyword(s):

Platelet Aggregation ◽

Xanthine Oxidase ◽

Canine Model ◽

Pulsed Doppler ◽

Flow Probe ◽

Coronary Vein ◽

Cyclic Flow ◽

Important Mediator

We investigated the hypothesis that xanthine oxidase (XO) mediates platelet aggregation and cyclic flow variations (CFVs) in stenosed canine coronary arteries. CFVs were produced by an external constrictor placed at the site of the coronary artery with the injured endothelium. The severity of CFVs was evaluated by a pulsed Doppler flow probe. If CFVs developed, dogs intravenously received allopurinol, a specific XO inhibitor. The transcardiac gradient (difference between coronary vein and left atrium) of purine metabolites was determined during CFVs and after allopurinol administration. Allopurinol significantly reduced CFVs (from 8 +/- 1 to 1 +/- 1 cycles/h, P < 0.01, n = 14), whereas saline did not (from 8 +/- 1 to 7 +/- 1 cycles/h, n = 7). In seven dogs with CFVs, the transcardiac gradient of xanthine and uric acid concentrations significantly increased after the establishment of CFVs and significantly decreased after the administration of allopurinol. In vitro platelet studies showed that XO enhanced (from 30.9 +/- 2.0 to 47.6 +/- 1.5%, P < 0.0001, n = 10) and allopurinol inhibited ADP-induced platelet aggregation (from 48.3 +/- 1.3 to 24.8 +/- 1.5%, P < 0.0001, n = 10). Our results indicate that allopurinol inhibits platelet aggregation in vitro and provides a protection against CFVs in vivo. Thus XO may be an important mediator in this model.

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