Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 45
Filter
1.
Vet Pathol ; 61(5): 765-770, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38695516

ABSTRACT

Alternative therapies that can help achieve complete remission in dogs with lymphoma include total body irradiation and hematopoietic cell transplant, though there are few reports describing successes and pathologic sequelae of these procedures. During a 10-year period, 94 dogs with multicentric lymphoma received a hematopoietic cell transplant following total body irradiation at North Carolina State University College of Veterinary Medicine. Seven of these 94 dogs (7%) died prior to discharge, five (5%) of which presented for postmortem examination. Of these dogs, four received an autologous hematopoietic cell transplant, while one received a haploidentical allogeneic hematopoietic cell transplant. All five dogs had bone marrow depletion with all hematopoietic lines affected. Three had systemic candidiasis, while two had bacterial infections. To the authors' knowledge, this is the first report to document pathologic findings and development of systemic mycoses in dogs post total-body irradiation therapy and hematopoietic cell transplant.


Subject(s)
Dog Diseases , Hematopoietic Stem Cell Transplantation , Lymphoma, B-Cell , Whole-Body Irradiation , Animals , Dogs , Hematopoietic Stem Cell Transplantation/veterinary , Whole-Body Irradiation/veterinary , Dog Diseases/pathology , Dog Diseases/radiotherapy , Male , Female , Lymphoma, B-Cell/veterinary , Lymphoma, B-Cell/pathology , Lymphoma, B-Cell/radiotherapy
2.
Vet Radiol Ultrasound ; 60(5): 586-593, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31146304

ABSTRACT

A total body irradiation (TBI) protocol was developed to support a bone marrow transplant (BMT) program for the treatment of canine hematologic malignancies. The purpose of this prospective study is to describe implementation of the protocol and resultant dosimetry. Nongraphic manual treatment planning using 6 MV photons, isocentric delivery, 40 × 40 cm field size, wall-mounted lasers to verify positioning, a lucite beam spoiler (without use of bolus material), a dose rate of 8.75 cGy/min at patient isocenter, and a source-to-axis distance of 338 cm were used for TBI. A monitor unit calculation formula was derived using ion chamber measurements and a solid water phantom. Five thermoluminescent dosimeters (TLDs) were used at various anatomic locations in each of four cadaver dogs, to verify fidelity of the monitor unit formula prior to clinical implementation. In vivo dosimetric data were then collected with five TLDs at various anatomic locations in six patients treated with TBI. A total dose of 10 Gy divided into two 5 Gy fractions was delivered approximately 16 h apart, immediately followed by autologous stem cell transplant. The mean difference between prescribed and delivered doses ranged from 99% to 109% for various sites in cadavers, and from 83% to 121% in clinical patients. The mean total body dose in cadavers and clinical patients when whole body dose was estimated by averaging doses measured by variably placed TLDs ranged from 98% to 108% and 93% to 102% of the prescribed dose, respectively, which was considered acceptable. This protocol could be used for institutional implementation of TBI.


Subject(s)
Bone Marrow Transplantation/veterinary , Dog Diseases/radiotherapy , Leukemia/veterinary , Lymphoma/veterinary , Photons , Whole-Body Irradiation/veterinary , Animals , Bone Marrow Transplantation/methods , Dogs , Female , Leukemia/radiotherapy , Lymphoma/radiotherapy , Male , Prospective Studies , Radiotherapy Dosage/veterinary , Whole-Body Irradiation/methods
3.
Vet Dermatol ; 28(2): 246-e65, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28133821

ABSTRACT

BACKGROUND: Mycosis fungoides (MF) is an uncommon cutaneous neoplasm in dogs. Treatment options are limited. Total skin electron therapy (TSET) has been suggested as a possible therapy for canine MF. OBJECTIVE: To describe the use of TSET as palliative treatment for MF in a dog. RESULTS: An adult dog, previously diagnosed with nonepidermolytic ichthyosis, was presented with generalized erythroderma, alopecia and erosions. Histopathology revealed a densely cellular, well-demarcated, unencapsulated infiltrate extending from the epidermis to the mid-dermis compatible with MF. The infiltrate exhibited epitheliotropism multifocally for the epidermis, infundibula and adnexa. Due to a lack of response to chemotherapy, TSET was elected. Six megavoltage electrons were delivered using a 21EX Varian linear accelerator. A dose of 6 Gy was delivered to the skin surface and a 100 cm skin to surface distance was used for dog setup. The treatment time for the cranial half treatment was 3 h. The treatment was divided in two sessions (cranial and caudal halves of the body) 15 days apart. Clinical and histopathological complete remission was achieved and the dog was kept in remission with no additional treatments for 19 months before relapse and development of Sézary syndrome. CONCLUSION AND CLINICAL SIGNIFICANCE: To the best of the authors' knowledge, this is the first case reporting the use of TSET for medically refractory canine MF with post treatment follow-up. This case suggests that the use of TSET may be an effective palliative treatment for canine MF.


Subject(s)
Dog Diseases/therapy , Mycosis Fungoides/veterinary , Skin Neoplasms/veterinary , Whole-Body Irradiation/veterinary , Animals , Dog Diseases/radiotherapy , Dogs , Fatal Outcome , Female , Mycosis Fungoides/pathology , Mycosis Fungoides/radiotherapy , Skin Neoplasms/pathology , Skin Neoplasms/radiotherapy
4.
Vet Pathol ; 49(2): 341-3, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21670196

ABSTRACT

Dogs with and without lymphoma have undergone hematopoietic cell transplantation in a research setting for decades. North Carolina State University is currently treating dogs with B- and T-cell lymphoma in a clinical setting with autologous peripheral blood progenitor cell transplants, using peripheral blood CD34+ progenitor cells harvested using an apheresis machine. Complete blood counts were performed daily for 15 to 19 days posttransplantation to monitor peripheral blood cell nadirs and subsequent CD34+ cell engraftment. This study documents the hematologic toxicities of total body irradiation in 10 dogs and the subsequent recovery of the affected cell lines after peripheral blood progenitor cell transplant, indicating successful CD34+ engraftment. All peripheral blood cell lines, excluding red blood cells, experienced grade 4 toxicities. All dogs had ≥ 500 neutrophils/µl by day 12, while thrombocytopenia persisted for many weeks. All dogs were clinically normal at discharge.


Subject(s)
Dog Diseases/therapy , Hematopoietic Stem Cell Transplantation/veterinary , Lymphoma/veterinary , Whole-Body Irradiation/veterinary , Animals , Antigens, CD34/metabolism , Blood Cell Count/veterinary , Bone Marrow/radiation effects , Dogs , Graft Survival , Hematopoietic Stem Cell Transplantation/methods , Lymphoma/therapy , Transplantation, Autologous , Whole-Body Irradiation/adverse effects
5.
Toxicol Ind Health ; 28(9): 852-63, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22075690

ABSTRACT

The aim of this study was to evaluate the antiapoptotic and proliferative activity of curcumin (Cur) on the ovarian follicles in mice exposed to whole body ionizing radiation (Rd). The mice were exposed to 8.3 gray whole body Rd, and Cur groups were given as a daily dose of 100 mg/kg of Cur for 10 days (10 days before Rd). The ovaries were collected 3 and 12 h after irradiation. To date, no such studies have been performed on antiapoptotic and proliferative activity of Cur on the ovarian follicles in mice exposed to whole body Rd. Analysis of mice ovary after exposure to Rd by terminal-deoxynucleotidyl-transferase-mediated dUTP nick end labeling showed that there were apoptotic cells both in the follicular wall and the antrum, and that the number of follicles showing early atresic features was high 3 h after Rd. On the other hand, analysis of mice ovary 12 h after exposure to Rd showed that the number of follicles containing apoptotic cells with advanced atresic features was significantly higher when compared to the 3-h Rd exposure group. The proliferating cell nuclear antigen -positive granulosa cells were decreased in association with follicular atresia. The groups given treatment were observed to have some benefit from Cur against the damage caused by Rd. The results of this study demonstrate that Cur prevents follicular atresia in Rd-induced apoptosis in ovarian follicles.


Subject(s)
Apoptosis/drug effects , Cell Proliferation/radiation effects , Curcumin/pharmacology , Ovarian Follicle/drug effects , Ovarian Follicle/radiation effects , Animals , Female , Follicular Atresia/radiation effects , Granulosa Cells/drug effects , Granulosa Cells/radiation effects , In Situ Nick-End Labeling , Mice , Proliferating Cell Nuclear Antigen/metabolism , Whole-Body Irradiation/veterinary
6.
Sci Rep ; 10(1): 19899, 2020 11 16.
Article in English | MEDLINE | ID: mdl-33199728

ABSTRACT

In the long term, 137Cs is probably the most biologically important agent released in many accidental (or malicious) radiation disasters. It can enter the food chain, and be consumed, or, if present in the environment (e.g. from fallout), can provide external irradiation over prolonged times. In either case, due to the high penetration of the energetic γ rays emitted by 137Cs, the individual will be exposed to a low dose rate, uniform, whole body, irradiation. The VADER (VAriable Dose-rate External 137Cs irradiatoR) allows modeling these exposures, bypassing many of the problems inherent in internal emitter studies. Making use of discarded 137Cs brachytherapy seeds, the VADER can provide varying low dose rate irradiations at dose rates of 0.1 to 1.2 Gy/day. The VADER includes a mouse "hotel", designed to allow long term simultaneous residency of up to 15 mice. Two source platters containing ~ 250 mCi each of 137Cs brachytherapy seeds are mounted above and below the "hotel" and can be moved under computer control to provide constant low dose rate or a varying dose rate mimicking 137Cs biokinetics in mouse or man. We present the VADER design and characterization of its performance over 18 months of use.


Subject(s)
Brachytherapy/instrumentation , Brachytherapy/veterinary , Cesium Radioisotopes/analysis , Whole-Body Irradiation/instrumentation , Whole-Body Irradiation/veterinary , Animals , Equipment Design , Gamma Rays , Mice , Mice, Inbred C57BL , Radiation Dosage
7.
Metabolism ; 103: 154025, 2020 02.
Article in English | MEDLINE | ID: mdl-31765667

ABSTRACT

BACKGROUND: Metabolic complications are highly prevalent in cancer survivors treated with irradiation but the underlying mechanisms remain unknown. METHODS: Chow or high fat-fed C57Bl/6J mice were irradiated (6Gy) before investigating the impact on whole-body or skeletal muscle metabolism and profiling their lipidomic signature. Using a transgenic mouse model (Tg:Pax7-nGFP), we isolated muscle progenitor cells (satellite cells) and characterised their metabolic functions. We recruited childhood cancer survivors, grouped them based on the use of total body irradiation during their treatment and established their lipidomic profile. RESULTS: In mice, irradiation delayed body weight gain and impaired fat pads and muscle weights. These changes were associated with impaired whole-body fat oxidation in chow-fed mice and altered ex vivo skeletal muscle fatty acid oxidation, potentially due to a reduction in oxidative fibres and reduced mitochondrial enzyme activity. Irradiation led to fasting hyperglycaemia and impaired glucose uptake in isolated skeletal muscles. Cultured satellite cells from irradiated mice showed decreased fatty acid oxidation and reduced glucose uptake, recapitulating the host metabolic phenotype. Irradiation resulted in a remodelling of lipid species in skeletal muscles, with the extensor digitorum longus muscle being particularly affected. A large number of lipid species were reduced, with several of these species showing a positive correlation with mitochondrial enzymes activity. In cancer survivors exposed to irradiation, we found a similar decrease in systemic levels of most lipid species, and lipid species that increased were positively correlated with insulin resistance (HOMA-IR). CONCLUSION: Irradiation leads to long-term alterations in body composition, and lipid and carbohydrate metabolism in skeletal muscle, and affects muscle progenitor cells. Such changes result in persistent impairment of metabolic functions, providing a new mechanism for the increased prevalence of metabolic diseases reported in irradiated individuals. In this context, changes in the lipidomic signature in response to irradiation could be of diagnostic value.


Subject(s)
Cancer Survivors , Metabolic Diseases/etiology , Mitochondria/radiation effects , Muscle, Skeletal/radiation effects , Neoplasms/radiotherapy , Whole-Body Irradiation/adverse effects , Adolescent , Adult , Animals , Child , Child, Preschool , Energy Metabolism/radiation effects , Female , Follow-Up Studies , Humans , Male , Metabolic Diseases/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Mitochondria/physiology , Muscle, Skeletal/metabolism , Neoplasms/metabolism , Oxidation-Reduction/radiation effects , Radiation Injuries/metabolism , Radiation Injuries/pathology , Whole-Body Irradiation/veterinary , X-Ray Therapy , X-Rays/adverse effects , Young Adult
8.
Reprod Biol Endocrinol ; 7: 130, 2009 Nov 19.
Article in English | MEDLINE | ID: mdl-19925657

ABSTRACT

BACKGROUND: Irradiation or chemotherapy that suspend normal spermatogenesis is commonly used to treat various cancers. Fortunately, spermatogenesis in many cases can be restored after such treatments but knowledge is limited about the re-initiation process. Earlier studies have described the cellular changes that happen during recovery from irradiation by means of histology. We have earlier generated gene expression profiles during induction of spermatogenesis in mouse postnatal developing testes and found a correlation between profiles and the expressing cell types. The aim of the present work was to utilize the link between expression profile and cell types to follow the cellular changes that occur during post-irradiation recovery of spermatogenesis in order to describe recovery by means of gene expression. METHODS: Adult mouse testes were subjected to irradiation with 1 Gy or a fractionated radiation of two times 1 Gy. Testes were sampled every third or fourth day to follow the recovery of spermatogenesis and gene expression profiles generated by means of differential display RT-PCR. In situ hybridization was in addition performed to verify cell-type specific gene expression patterns. RESULTS: Irradiation of mice testis created a gap in spermatogenesis, which was initiated by loss of A1 to B-spermatogonia and lasted for approximately 10 days. Irradiation with 2 times 1 Gy showed a more pronounced effect on germ cell elimination than with 1 Gy, but spermatogenesis was in both cases completely reconstituted 42 days after irradiation. Comparison of expression profiles indicated that the cellular reconstitution appeared equivalent to what is observed during induction of normal spermatogenesis. CONCLUSION: The data indicates that recovery of spermatogenesis can be monitored by means of gene expression, which could aid in designing radiation treatment regimes for cancer patients leading to better restoration of spermatogenesis.


Subject(s)
Gene Expression Profiling , Recovery of Function/genetics , Spermatogenesis/genetics , Spermatogenesis/radiation effects , Animals , Body Weight/radiation effects , DNA-Binding Proteins , GATA1 Transcription Factor/genetics , GATA1 Transcription Factor/metabolism , Male , Mice , Mice, Inbred C3H , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Organ Size/radiation effects , Organ Specificity/genetics , Organ Specificity/radiation effects , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Spermatogenesis/physiology , Spermatogonia/metabolism , Spermatogonia/radiation effects , Testis/anatomy & histology , Testis/metabolism , Testis/radiation effects , Vesicular Transport Proteins/genetics , Vesicular Transport Proteins/metabolism , Whole-Body Irradiation/veterinary
9.
Bioelectromagnetics ; 30(1): 36-44, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18671234

ABSTRACT

Exposure to man-made electromagnetic fields has increased over the past century. As a result of exposure to these fields, concerns have been raised regarding the relationship between electromagnetic fields and human health. Interest in the biological and health effects of intermediate frequency (IF) magnetic fields has grown recently because of the increase in public concern. In order to investigate whether IF magnetic fields have biological effects, we have developed a 20 kHz (IF) magnetic field exposure system for in vivo studies. The exposure facility was designed to study the biological effects of IF magnetic field on laboratory animals. The facility consists of a 9 m x 9 m x 5 m high room containing seven separate rooms including a 5.3 m x 4.5 m x 3 m high specific-pathogen free exposure room. The dimensions of the exposure system are 1.6 m x 1.6 m x 1.616 m high located inside this exposure room. The system is designed to provide magnetic fields up to 200 microT at 20 kHz with the uniformity within +/-5% over the space occupied by animals. After constructing the facility, performance tests were carried out. As a result, it was confirmed that our facility met requirements for evaluation of the biological effects of IF magnetic field on small animal experiments. In this paper, the design, construction, and results of evaluation of an animal exposure facility for the in vivo biological effects of an IF magnetic field are described.


Subject(s)
Biological Assay/instrumentation , Biological Assay/veterinary , Environmental Exposure , Whole-Body Irradiation/instrumentation , Whole-Body Irradiation/veterinary , Animals , Electromagnetic Fields , Equipment Design , Equipment Failure Analysis
10.
Clin Invest Med ; 31(4): E182-8, 2008.
Article in English | MEDLINE | ID: mdl-18682041

ABSTRACT

PURPOSE: To investigate the possible protective effects of aminoguanidine (AG ) on lung damage in whole body irradiated rats. METHODS: To evaluate the biological damage of radiation on rat lung tissue, lipid peroxidation products were measured using biochemical parameters. Thirty Wistar albino rats were divided into three subgroups: control (C) , irradiation alone (RT), and RT + AG combined. After sacrificing the rats, antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) activities and malondiadehyde (MDA), nitric oxide (NO) levels were evaluated in lung tissue. RESULTS: Administration of AG resulted in an increase in the activities of CAT, SOD and GSHPx in the lungs. All were reduced after radiation. In addition, AG administration resulted in a decrease in both NO and MDA levels in lung compared with the irradiated group. CONCLUSION: Amnoguanidine increased the endogenous antioxidant defence mechanism in rats and protected the animals from radiation-induced lung toxicity. Moreover, AG may protect against ionizing radiation-induced lung damage because of its antioxidant effect.


Subject(s)
Enzyme Inhibitors/therapeutic use , Guanidines/therapeutic use , Lung/drug effects , Oxidative Stress/drug effects , Radiation Injuries, Experimental/prevention & control , Radiation, Ionizing , Respiratory Distress Syndrome/prevention & control , Animals , Catalase/metabolism , Disease Models, Animal , Glutathione Peroxidase/metabolism , Lung/enzymology , Lung/radiation effects , Male , Malondialdehyde/metabolism , Nitric Oxide/metabolism , Oxidative Stress/radiation effects , Radiation Injuries, Experimental/metabolism , Rats , Rats, Wistar , Superoxide Dismutase/metabolism , Whole-Body Irradiation/adverse effects , Whole-Body Irradiation/veterinary
11.
J Vet Sci ; 9(3): 281-4, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18716448

ABSTRACT

The radioprotective activity of extracts from the red seaweed Callophyllis (C.) japonica was investigated in mice that underwent whole-body exposure to gamma radiation. A methanol extract of C. japonica and its fractions [hexane, ethyl acetate (EtOAc), butanol and the remaining H2O] were used. Each fraction (100 mg/kg body weight) was administered intraperitoneally (i.p.) 2 times into the BALB/c mice, once at 1 and once at 24 h before exposure to 9 Gray (Gy) of gamma radiation. Pre-irradiation administration of the hexane and EtOAc fractions saved the mice, with their survival rates being greater than 80% at 30 days post-irradiation; the mice that were pretreated with the other fractions showed survival rates lower than 20% over the same time period. To examine the effect of each C. japonica fraction on the survival of intestinal and bone marrow stem cells, the number of intestinal crypts and bone marrow cells in the gamma-irradiated mice were examined. Pre-treatment of mice (i.p., 100 mg/kg body weight at 1 and 24 h before irradiation) with the hexane or EtOAc fraction prior to 6-Gy irradiation significantly protected the number of jejunal crypts and bone marrow cells at 9 days after irradiation. These findings suggest that certain extracts from C. japonica, when they are administered prior to irradiation, play an important role in the survival of irradiated mice, and this is possibly due to the extracts protecting the hematopoietic cells and intestinal stem cells against gamma irradiation.


Subject(s)
Bone Marrow Cells/radiation effects , Plant Extracts/pharmacology , Radiation-Protective Agents/pharmacology , Seaweed , Whole-Body Irradiation/veterinary , Acetates , Animals , Bone Marrow Cells/drug effects , Cell Survival/drug effects , Female , Gamma Rays , Hexanes , Intestinal Mucosa/cytology , Intestinal Mucosa/drug effects , Intestinal Mucosa/radiation effects , Jejunum/cytology , Jejunum/drug effects , Jejunum/radiation effects , Mice , Mice, Inbred BALB C , Radiation Injuries, Experimental/prevention & control
12.
Int J Radiat Biol ; 83(1): 65-71, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17357441

ABSTRACT

PURPOSE: To examine how folate status in a body is influenced by oxidative stress. MATERIAL AND METHODS: Mice were given total body irradiation (TBI) by X-ray, and changes in the concentration of folate were compared to those in vitamins C and E. RESULTS: In a time-dependent study, folate in plasma and bone marrow decreased from 5 h until 120 h post-TBI at 3 Gy. Folate in plasma and bone marrow decreased in a dose-dependent manner at 24 h. Marked decreases of vitamins C and E were also detected in bone marrow, but not in plasma even at 10 Gy of TBI. The susceptibility of plasma folate by irradiation was confirmed by an in vitro exposure study. Neither vitamins C and E nor folate were decreased in the liver by TBI. CONCLUSION: It is suggested that folate is vulnerable to oxidative stress, and folate may need to be evaluated, particularly for TBI or radiotherapy.


Subject(s)
Bone Marrow/radiation effects , Folic Acid/blood , Liver/radiation effects , Oxidative Stress/radiation effects , Whole-Body Irradiation/adverse effects , Animals , Ascorbic Acid/blood , Bone Marrow/chemistry , Dose-Response Relationship, Radiation , Liver/pathology , Mice , Mice, Inbred ICR , Time Factors , Vitamin E/blood , Whole-Body Irradiation/veterinary , X-Rays
13.
Comp Med ; 57(3): 287-91, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17605344

ABSTRACT

Intussusception is a common complication after canine hematopoietic cell transplantation (HCT). The present study was undertaken to evaluate predisposing factors of intussusception and to test whether intussusception can be managed surgically during the period immediately after HCT. We determined the incidence of intussusception after HCT was performed in 325 canine recipients (autologous, n = 43; allogeneic, n = 282) during the interval from January 2002 to May 2005. Intussusception was diagnosed in 16 of 325 dogs (4.9%). Intussusception was not significantly associated with the dose of irradiation, source of hematopoietic graft, use of immunosuppressive agents, gender, or age at transplant. A group of 9 of the affected dogs underwent small-bowel resection after diagnosis, and 7 were managed without surgical intervention. Despite complicating factors such as gastrointestinal toxicity and low neutrophil and platelet counts induced by the marrow conditioning regimen and the use of immunosuppressive agents, successful surgical management of intussusception was achieved in 6 of 9 dogs, as compared with successful management of 0 of 7 without surgery. Intussusception did not recur after surgical intervention in any dog. Recent HCT and post-transplant immunosuppressive therapy are not absolute contraindications to surgical intervention for intussusception in canine recipients of HCT.


Subject(s)
Dog Diseases/etiology , Hematopoietic Stem Cell Transplantation/adverse effects , Ileal Diseases/veterinary , Intussusception/veterinary , Animals , Dog Diseases/diagnostic imaging , Dog Diseases/surgery , Dogs , Female , Ileal Diseases/diagnostic imaging , Ileal Diseases/etiology , Ileal Diseases/surgery , Immunosuppressive Agents/adverse effects , Intussusception/diagnostic imaging , Intussusception/etiology , Intussusception/surgery , Male , Risk Factors , Transplantation Conditioning/veterinary , Ultrasonography , Whole-Body Irradiation/veterinary
14.
J Wildl Dis ; 43(4): 645-52, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17984259

ABSTRACT

Frog virus 3 (FV3) or FV3-like viruses (Iridoviridae) infect a wide range of amphibian species, and they are becoming increasingly and causally associated with amphibian disease outbreaks worldwide. We have established the frog Xenopus laevis as an experimental model to study host defense and pathogenesis of FV3 infection. Although X. laevis adults usually clear FV3 infection within a few weeks, viral DNA has been detected in the kidneys several months after they had been experimentally infected; virus also has been detected in seemingly healthy nonexperimentally infected adults. Based on this information, we hypothesized that covert FV3 infection may occur in Xenopus. We first conducted a survey that detected FV3 by polymerase chain reaction (PCR) in the kidneys (the main site of FV3 infection) in a significant fraction of X. laevis raised in five different locations in the United States. Asymptomatic FV3 carriers also were detected by initiation of an acute systemic FV3 infection in frogs that had been immunosupressed by sublethal gamma-irradiation. Finally, we focused on macrophages as a potential site for viral persistence, and we showed that FV3 can infect peritoneal macrophages in vitro as determined by reverse transcriptase-PCR detection of viral mRNAs. Unlike kidney cell lines that are readily killed by FV3, infected macrophages, like uninfected macrophages, survived up to 12 days. Viral transcription also was detected in macrophages from animals up to 12 days after infection. These results suggest that FV3 can become quiescent in resistant species such as Xenopus, thereby making these species potential viral reservoirs.


Subject(s)
DNA Virus Infections/veterinary , Macrophages/virology , Ranavirus/pathogenicity , Xenopus laevis/immunology , Xenopus laevis/virology , Animals , Carrier State/veterinary , DNA Virus Infections/transmission , DNA Virus Infections/virology , Disease Reservoirs/veterinary , Disease Reservoirs/virology , Gamma Rays , Immunocompromised Host/immunology , Kidney/virology , Macrophages/immunology , Neutralization Tests , Polymerase Chain Reaction/methods , Polymerase Chain Reaction/veterinary , RNA, Messenger/isolation & purification , RNA, Viral/isolation & purification , Ranavirus/immunology , Whole-Body Irradiation/veterinary
15.
Radiat Res ; 187(4): 433-442, 2017 04.
Article in English | MEDLINE | ID: mdl-28140787

ABSTRACT

Anatomically accurate phantoms are useful tools for radiation dosimetry studies. In this work, we demonstrate the construction of a new generation of life-like mouse phantoms in which the methods have been generalized to be applicable to the fabrication of any small animal. The mouse phantoms, with built-in density inhomogeneity, exhibit different scattering behavior dependent on where the radiation is delivered. Computer models of the mouse phantoms and a small animal irradiation platform were devised in Monte Carlo N-Particle code (MCNP). A baseline test replicating the irradiation system in a computational model shows minimal differences from experimental results from 50 Gy down to 0.1 Gy. We observe excellent agreement between scattered dose measurements and simulation results from X-ray irradiations focused at either the lung or the abdomen within our phantoms. This study demonstrates the utility of our mouse phantoms as measurement tools with the goal of using our phantoms to verify complex computational models.


Subject(s)
Biomimetic Materials/radiation effects , Phantoms, Imaging/veterinary , Radiometry/instrumentation , Radiometry/veterinary , Scattering, Radiation , Whole-Body Irradiation/veterinary , Animals , Computer Simulation , Equipment Design , Equipment Failure Analysis , Mice , Models, Biological , Radiation Dosage , Reproducibility of Results , Sensitivity and Specificity , Tomography, X-Ray Computed/instrumentation , Tomography, X-Ray Computed/veterinary , Whole-Body Irradiation/instrumentation
16.
Malar J ; 5: 41, 2006 May 15.
Article in English | MEDLINE | ID: mdl-16700906

ABSTRACT

BACKGROUND: In the context of the Sterile Insect Technique (SIT), radiation-induced sterility in the malaria mosquito Anopheles arabiensis Patton (Diptera: Culicidae) was studied. Male mosquitoes were exposed to gamma rays in the pupal or adult stage and dose-sterility curves were determined. METHODS: Pupae were irradiated shortly before emergence (at 22-26 hrs of age), and adults <24 hrs post emergence. Doses tested ranged between 0 and 100 Gy. The effects of irradiation on adult emergence, male survival, induced sterility and insemination capability were evaluated. Emergence and insemination data were analysed using independent t-tests against the control. Correlation analyses were performed for insemination rate and dose and insemination and fecundity. Male survival was analysed using Kaplan-Meier survival analyses. Finally, the calculated residual fertility values were inverse-normal transformed and linear regression analyses performed. RESULTS: Irradiation of pupae, for all doses tested, had no effect on adult emergence. Survival curves of males irradiated as pupae or adults were similar or even slightly higher than non-irradiated males. Overall, adults appeared to be slightly more susceptible to irradiation, although no significant differences for individual doses were observed. In the pupal stage, a significant negative correlation was found between insemination and dose, but the correlation-coefficient was associated with less than 25% of the total variation. A review of the literature indicated that An. arabiensis is more radiation resistant than other anopheline mosquitoes. CONCLUSION: The optimal dose for male insects to be released in an SIT programme depends on their level of sterility and competitiveness. The use of semi-sterilizing doses to produce more competitive insects is discussed. The most convenient developmental stage for mosquito irradiation on a mass-scale are pupae, but pupal irradiation resulted in a lower insemination rate at the highest dose compared to adult irradiation. On the basis of this study, a suitable dose range that includes semi-sterilizing doses is identified to initiate competitiveness experiments for males irradiated at both developmental stages.


Subject(s)
Anopheles/radiation effects , Insect Vectors/radiation effects , Life Cycle Stages/radiation effects , Whole-Body Irradiation/veterinary , Animals , Anopheles/physiology , Dose-Response Relationship, Radiation , Female , Fertility/radiation effects , Gamma Rays , Insect Vectors/physiology , Longevity/radiation effects , Male , Pupa/radiation effects , Regression Analysis , Survival Analysis , Time Factors , Whole-Body Irradiation/instrumentation
17.
Phys Med Biol ; 51(20): 5211-29, 2006 Oct 21.
Article in English | MEDLINE | ID: mdl-17019034

ABSTRACT

This paper presents the design, optimization, realization and verification of novel whole-body exposure setups for rats. The setups operating at 902 MHz and 1747 MHz provide highly efficient, National Toxicology Program (NTP) compatible and well-characterized exposures. They are compared to existing concepts of exposure setups with respect to efficiency, induced field uniformity, good laboratory practice (GLP) compatibility and cost. The novel exposure setup consists of a circular cascade of 17 sectorial waveguides excited by a novel loop antenna placed in the centre. The 70% overall efficiency of the exposure setup surpasses comparable values of existing setups. A field uniformity inside the phantom of more than 86% for the 1g cubical averaged specific absorption rate (SAR) within +/-5 dB of the whole-body SAR (WB-SAR) was attained. The uniformity of the exposure inside the setup, defined as the variation of the WB-SAR between animals, was better than +/-24%. Using only stainless steel, gold and polycarbonate in the vicinity of the animals ensured full GLP compatibility. The entire exposure system features fully automated computer controlled exposure and data monitoring, data storing and failure handling. Therefore, the proposed exposure system can be used to run blinded large scale, long-term exposure studies.


Subject(s)
Radiometry , Research/instrumentation , Whole-Body Irradiation/instrumentation , Whole-Body Irradiation/veterinary , Animals , Body Burden , Equipment Design , Equipment Failure Analysis , Radiation Dosage , Rats , Relative Biological Effectiveness
18.
J Am Vet Med Assoc ; 228(5): 728-32, 2006 Mar 01.
Article in English | MEDLINE | ID: mdl-16506937

ABSTRACT

CASE DESCRIPTION: A 7-year-old Golden Retriever was examined because of anorexia, lethargy, vomiting, and gradual weight loss. CLINICAL FINDINGS: Splenomegaly, pancytopenia, high serum calcium concentration, and high alkaline phosphatase activity were detected. Magnetic resonance imaging revealed an enlarged mesenteric lymph node and increased signals from the bone marrow of the ilium and vertebral bodies. Histologic examination and immunophenotyping of biopsy specimens confirmed a stage V (b) T-cell malignant lymphoma. TREATMENT AND OUTCOME: Clinical remission was attained by use of 2 chemotherapy cycles, followed by an allogeneic hematopoietic cell transplant performed at 18 weeks after diagnosis. A donor was identified by molecular dog leukocyte antigen typing methods. The patient was conditioned with 2 fractions of 4 Gy total body irradiation delivered 3 hours apart at 7 cGy/min, followed by an IV infusion of recombinant canine granulocyte colony-stimulating factor mobilized leukapheresis product and postgrafting immunosuppression with cyclosporine. Chimerism analyses revealed full donor engraftment that has been maintained for at least 58 weeks after transplant. Remission has been confirmed by normal results of serum thymidine kinase assays and the absence of peripheral blood clonal T-cell receptor gene rearrangements. CLINICAL RELEVANCE: Systemic chemotherapy induces remissions; however, most dogs succumb to disease recurrence because of multidrug resistance. Outcome of allogeneic hematopoietic cell transplantation in dogs can be excellent because of improved donor-recipient selection by use of molecular dog leukocyte antigen typing, compared with early attempts, and better prevention of graft versus host disease, better supportive care, and substitution of peripheral blood mononuclear cells for bone marrow.


Subject(s)
Dog Diseases/therapy , Hematopoietic Stem Cell Transplantation/veterinary , Histocompatibility Antigens/immunology , Immunosuppression Therapy/veterinary , Lymphoma, T-Cell/veterinary , Animals , Cyclosporine/pharmacology , Dogs , Graft Survival , Granulocyte Colony-Stimulating Factor/pharmacology , Hematopoietic Stem Cell Mobilization , Hematopoietic Stem Cell Transplantation/methods , Histocompatibility Testing , Immunosuppression Therapy/methods , Lymphoma, T-Cell/therapy , Male , Transplantation Chimera , Transplantation, Homologous/veterinary , Treatment Outcome , Whole-Body Irradiation/veterinary
19.
Health Phys ; 110(2 Suppl 1): S26-38, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26710162

ABSTRACT

Shielded Cs irradiators are routinely used in pre-clinical radiation research to perform in vitro or in vivo investigations. Without appropriate dosimetry and irradiation protocols in place, there can be large uncertainty in the delivered dose of radiation between irradiated subjects that could lead to inaccurate and possibly misleading results. Here, a dosimetric evaluation of the JL Shepard Mark I-68A Cs irradiator and an irradiation technique for whole-body irradiation of small animals that allows one to limit the between subject variation in delivered dose to ±3% are provided. Mathematical simulation techniques and Gafchromic EBT film were used to describe the region within the irradiation cavity with homogeneous dose distribution (100% ± 5%), the dosimetric impact of varying source-to-subject distance, and the variation in attenuation thickness due to turntable rotation. Furthermore, an irradiation protocol and dosimetry formalism that allows calculation of irradiation time for whole-body irradiation of small animals is proposed that is designed to ensure a more consistent dose delivery between irradiated subjects. To compare this protocol with the conventional irradiation protocol suggested by the vendor, high-resolution film dosimetry measurements evaluating the dose difference between irradiation subjects and the dose distribution throughout subjects was performed using phantoms resembling small animals. Based on these results, there can be considerable variation in the delivered dose of > ± 5% using the conventional irradiation protocol for whole-body irradiation doses below 5 Gy. Using the proposed irradiation protocol this variability can be reduced to within ±3% and the dosimetry formalism allows for more accurate calculation of the irradiation time in relation to the intended prescription dose.


Subject(s)
Algorithms , Cesium Radioisotopes/analysis , Radiometry/instrumentation , Radiometry/methods , Whole-Body Irradiation/instrumentation , Whole-Body Irradiation/veterinary , Animals , Equipment Design , Equipment Failure Analysis , Mice , Reproducibility of Results , Sensitivity and Specificity
20.
Am J Chin Med ; 33(2): 231-40, 2005.
Article in English | MEDLINE | ID: mdl-15974482

ABSTRACT

In this study, we focused on immune stimulation by Propolis, and examined changes in the effect of irradiation after Propolis administration. We also examined the radioprotective effect of Propolis by observing its effect on the immune system. The effect of immune activation by Propolis was investigated by measuring the total immunoglobulin (Ig) G and IgM. The radioprotective effect of immune activation by Propolis was investigated by measuring the T-lymphocyte subsets in the peripheral blood of mice following whole body irradiation. Compared with the control group, the IgG was significantly reduced in the Propolis group, indicating that Propolis suppressed IgG production. ELISA revealed that the amount of IgM in mouse serum was significantly higher in the Propolis group as compared with the control group, indicating that Propolis increased IgM production. The number of CD4-positive cells was increased only in the Propolis group. Likewise, the number of CD4-positive cells increased by 81% in the Propolis with irradiation group compared with the irradiation group alone. Compared with the control group, the Propolis group increased CD8-positive cells. Compared with the irradiation alone group, CD8-positive cells were decreased by Propolis with irradiation group. Propolis activated macrophages to stimulate interferon (IFN)-gamma production in association with the secondary activation of T-lymphocytes, resulting in a decrease in IgG and IgM production. Cytokines released from macrophages in mouse peripheral blood after Propolis administration activated helper T-cells to proliferate. In addition, activated macrophages in association with the secondary T-lymphocyte activation increased IFN-gamma production and stimulated proliferation of cytotoxic T-cells and suppressor T-cells, indicating the activation of cell-mediated immune responses.


Subject(s)
Propolis/pharmacology , Radiation-Protective Agents/pharmacology , T-Lymphocyte Subsets/radiation effects , Adjuvants, Immunologic , Animals , Cytokines/metabolism , Enzyme-Linked Immunosorbent Assay , Immunity/drug effects , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Macrophages/immunology , Male , Mice , Mice, Inbred C3H , T-Lymphocyte Subsets/drug effects , Whole-Body Irradiation/veterinary
SELECTION OF CITATIONS
SEARCH DETAIL