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1.
J Phys Chem A ; 128(27): 5362-5373, 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-38935631

RESUMEN

The thermal decomposition of perfluorooctanoic acid (PFOA) under oxidative conditions was investigated using air (O2) and N2O as oxidants over temperatures ranging from 400 to 1000 °C in an α-alumina reactor. In the presence of air, PFOA was found to decompose into perfluorohept-1-ene (C7F14) and perfluoroheptanoyl fluoride (C7F14O) in addition to HF, CO, and CO2. At temperatures above 800 °C, both C7F14 and C7F14O were no longer detected. A comprehensive analysis of the reaction mechanisms through quantum chemical analysis and kinetic modeling in combination with experimental observations was utilized to identify key reaction pathways. Quantum chemical analysis led to the conclusion that oxygen atoms are crucial in decomposing perfluoroalk-1-enes, especially the stable perfluorohept-1-ene (C7F14). Under oxidative conditions, it was found that significant quantities of C2F6 and CF4 were formed. Further quantum chemical analysis suggests that the O atoms facilitate the formation of volatile fluorinated compounds (VFCs) such as tetrafluoromethane (CF4) and hexafluoroethane (C2F6), particularly at higher temperatures. By elucidating these key reactions, an improved understanding of the potential formation products of incomplete combustion (PICs) or products of incomplete destruction (PIDs) is made.

2.
J Feline Med Surg ; 25(11): 1098612X231198416, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37975186

RESUMEN

CASE SERIES SUMMARY: This case series describes five cats with cutaneous adverse events after subcutaneous administration of frunevetmab, a felinised anti-nerve growth factor monoclonal antibody, including histopathological findings in one case. All cats displayed moderate to severe pruritus resulting in self-trauma to the neck and/or head, causing lesions ranging from superficial dermatitis to alopecia and ulcerations. There were no reactions at the injection sites. In one cat, clinical signs developed after the second frunevetmab dose the cat received, with no reaction noted after the first dose. For the remaining cats, clinical signs were observed after their first dose of frunevetmab. The onset of the first episode of pruritus and self-trauma was 3-18 days after the most recent frunevetmab injection. Three cats had one or more additional frunevetmab injections after the original adverse event and all had subsequent reactions. Subsequent reactions were either similar in time frame or occurred more rapidly, with similar or more severe pruritus compared with the original reactions. Treatments and outcomes varied between cases. RELEVANCE AND NOVEL INFORMATION: Frunevetmab is a novel, monthly injectable monoclonal antibody for the management of pain associated with osteoarthritis in cats. This is the first published report detailing the nature of cutaneous adverse events associated with this treatment, and the first report of the histopathological findings.


Asunto(s)
Enfermedades de los Gatos , Prurito , Animales , Gatos , Prurito/inducido químicamente , Prurito/veterinaria , Anticuerpos Monoclonales , Enfermedades de los Gatos/inducido químicamente , Enfermedades de los Gatos/tratamiento farmacológico
3.
J Wildl Dis ; 59(2): 371-375, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-36989511

RESUMEN

A wild lace monitor, Varanus varius, was euthanized due to an inoperable malignant anaplastic sarcoma that resembled hemangiosarcoma. Histopathologic examination identified metastatic spread to the lung, heart, and liver.


Asunto(s)
Lagartos , Sarcoma , Animales , Corazón , Sarcoma/veterinaria
4.
Vet Dermatol ; 32(3): 262-e72, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33830550

RESUMEN

BACKGROUND: Some dogs with chronic otitis externa (OE) develop proliferation of the tissues surrounding the opening of the external ear canal, resulting in obstruction. Traditionally total ear canal ablation with bulla osteotomy (TECABO) has been recommended. OBJECTIVES: To evaluate the efficacy of a novel treatment using carbon dioxide (CO2 ) laser surgery and to describe the histopathological features of chronic proliferative and obstructive OE. ANIMALS: Twenty-six dogs were included, 16 with bilateral and 10 with unilateral disease (42 ears were treated). Dogs with nonpatent horizontal ear canal or macroscopic calcification of the ear canal were excluded. For histopathological evaluation, tissue samples were collected from 11 dogs (17 ears). METHODS AND MATERIALS: Hyperplastic tissue around the canal opening and within the vertical ear canal was dissected and ablated using a CO2 laser. Biopsy samples were evaluated for sebaceous and ceruminous gland hyperplasia, epidermal hyperplasia, inflammation and fibrosis. RESULTS: Following CO2 laser surgery there was a good or excellent outcome with substantial resolution of proliferative changes in 39 of 42 ears from 24 of 26 dogs. One surgery was sufficient in 21 dogs and three dogs had two surgeries. Two dogs had recurrence of proliferative tissue after one surgery and underwent TECABO. Two dogs had no recurrence of proliferative tissue after surgery, yet had persistent luminal infection and underwent TECABO. The remainder of the dogs were effectively medically managed long-term following surgery. Histologically, eight ears had a predominantly sebaceous gland response, three had a predominantly ceruminous response and six had a mixed glandular pattern. Epidermal hyperplasia, inflammation and fibrosis varied from mild to severe. CONCLUSIONS AND CLINICAL RELEVANCE: Carbon dioxide laser surgery is an effective treatment of proliferative OE causing obstruction of the ear canal opening and vertical canal, and should be considered as an alternative to TECABO whenever possible.


Asunto(s)
Enfermedades de los Perros , Láseres de Gas , Otitis Externa , Animales , Enfermedades de los Perros/cirugía , Perros , Conducto Auditivo Externo/cirugía , Láseres de Gas/uso terapéutico , Osteotomía/veterinaria , Otitis Externa/cirugía , Otitis Externa/veterinaria
5.
J Zoo Wildl Med ; 52(1): 396-400, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33827204

RESUMEN

Microsporidia are obligate, intracellular fungi. In reptiles, they are most commonly reported in squamates. We report the first detection of microsporidiosis in inland bearded dragons (Pogona vitticeps) from Australia, and for the first time, mixed infections of microsporidium and adenovirus in asymptomatic inland bearded dragons. In one collection there were five individuals, one of which was lethargic, inappetent, and had lost weight. Two large ovarian granulomas were palpated (42 × 23 mm and 26 × 19 mm) and were surgically removed. This animal died shortly after surgery. Histological evaluation of these granulomas revealed granulomatous inflammation within or adjacent to ovarian tissue, containing numerous aggregates of microorganisms consistent with microsporidia. The organisms were confirmed as Encephalitozoon pogonae by polymerase chain reaction (PCR) and sequencing. Agamid adenovirus-1 was also detected. These two infectious agents were also detected by PCR in all the other bearded dragons in this collection (n = 5), all of which were asymptomatic. A single dragon from a second collection presented for a routine wellness examination after the sudden death of another dragon in the collection. This dragon had similar intracelomic masses to the dragon from the first collection. These were removed surgically, but the dragon died 5 wk later following 3 wk of treatment with 25 mg/kg fenbendazole PO q7 days. Necropsy samples were collected and the microsporidian Encephalitozoon pogonae was detected in oral-cloacal swabs, blood, and multiple tissues by PCR and sequencing. Agamid adenovirus-1 was not detected in this dragon.


Asunto(s)
Granuloma/veterinaria , Lagartos/microbiología , Microsporidios/aislamiento & purificación , Microsporidiosis/veterinaria , Animales , Femenino , Granuloma/microbiología , Microsporidios/clasificación , Microsporidiosis/patología , Enfermedades del Ovario/microbiología , Enfermedades del Ovario/patología
6.
Environ Sci Process Impacts ; 22(10): 2084-2094, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-32909592

RESUMEN

Chlorpyrifos (CPF) is a widely used pesticide; however, limited experimental work has been completed on its thermal decomposition. CPF is known to decompose into 3,5,6-trichloro-2-pyridinol (TCpyol) together with ethylene and HOPOS. Under oxidative conditions TCpyol can decompose into the dioxin-like 2,3,7,8-tetrachloro-[1,4]-dioxinodipyridine (TCDDPy). With CPF on the cusp of being banned in several jurisdictions worldwide, the question might arise as to how to safely eliminate large stockpiles of this pesticide. Thermal methods such as incineration or thermal desorption of pesticide-contaminated soils are often employed. To assess the safety of thermal methods, information about the toxicants arising from thermal treatment is essential. The present flow reactor study reports the products detected under inert and oxidative conditions from the decomposition of CPF representative of thermal treatments and of wildfires in CPF-contaminated vegetation. Ethylene and TCpyol are the initial products formed at temperatures between 550 and 650 °C, although the detection of HOPOS as a reaction product has proven to be elusive. During pyrolysis of CPF in an inert gas, the dominant sulfur-containing product detected from CPF is carbon disulfide. Quantum chemical analysis reveals that ethylene and HOPOS undergo a facile reaction to form thiirane (c-C2H4S) which subsequently undergoes ring opening reactions to form precursors of CS2. At elevated temperatures (>650 °C), TCpyol undergoes both decarbonylation and dehydroxylation reactions together with decomposition of its primary product, TCpyol. A substantial number of toxicants is observed, including HCN and several nitriles, including cyanogen. No CS2 is observed under oxidative conditions - sulfur dioxide is the fate of S in oxidation of CPF, and quantum chemical studies show that SO2 formation is initiated by the reaction between HOPOS and O2. The range of toxicants produced in thermal decomposition of CPF is summarised.


Asunto(s)
Cloropirifos , Dioxinas , Insecticidas , Plaguicidas , Dibenzodioxinas Policloradas , Estrés Oxidativo
7.
Lipids ; 55(4): 309-327, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32314395

RESUMEN

Ad libitum-fed diets high in fat and carbohydrate (especially fructose) induce weight gain, obesity, and nonalcoholic fatty liver disease (NAFLD) in humans and animal models. However, interpretation is complicated since ad libitum feeding of such diets induces hyperphagia and upregulates expression of liver fatty acid binding protein (L-FABP)-a protein intimately involved in fatty acid and glucose regulation of lipid metabolism. Wild-type (WT) and L-fabp gene ablated (LKO) mice were pair-fed either high-fat diet (HFD) or high-fat/high-glucose diet (HFGD) wherein total carbohydrate was maintained constant but the proportion of glucose was increased at the expense of fructose. In LKO mice, the pair-fed HFD increased body weight and lean tissue mass (LTM) but had no effect on fat tissue mass (FTM) or hepatic fatty vacuolation as compared to pair-fed WT counterparts. These LKO mice exhibited upregulation of hepatic proteins in fatty acid uptake and cytosolic transport (caveolin and sterol carrier protein-2), but lower hepatic fatty acid oxidation (decreased serum ß-hydroxybutyrate). LKO mice pair-fed HFGD also exhibited increased body weight; however, these mice had increased FTM, not LTM, and increased hepatic fatty vacuolation as compared to pair-fed WT counterparts. These LKO mice also exhibited upregulation of hepatic proteins in fatty acid uptake and cytosolic transport (caveolin and acyl-CoA binding protein, but not sterol carrier protein-2), but there was no change in hepatic fatty acid oxidation (serum ß-hydroxybutyrate) as compared to pair-fed WT counterparts.


Asunto(s)
Dieta Alta en Grasa/efectos adversos , Proteínas de Unión a Ácidos Grasos/genética , Glucosa/administración & dosificación , Ácido 3-Hidroxibutírico/sangre , Animales , Peso Corporal/efectos de los fármacos , Proteínas Portadoras/metabolismo , Caveolina 2/metabolismo , Ácidos Grasos/análisis , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Técnicas de Inactivación de Genes , Masculino , Ratones
8.
Environ Sci Technol ; 53(23): 13742-13747, 2019 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-31670504

RESUMEN

With health concerns developing about the use of glyphosate (phosphonomethylglycine, PMG), the world's most used herbicide, the possibility of destruction of stockpiles via incineration arises. Little is known, however, about the possible toxic products of decomposition. We have performed a quantum chemical computation of the mechanism of thermal decomposition of PMG. Two initiation channels, one producing sarcosine and the other producing N-methylaminomethylphosphonic acid, have been located. Both the initial products decompose to dimethylamine (DMA), and the mechanism of further decomposition and toxic products is explored. Global potential energy surfaces for the initial decomposition of DMA are presented together with chemical kinetic modeling wherein the rate constants employed have been calculated from the quantum chemical data. Time and temperature evolution of the expected toxic products are presented and discussed.


Asunto(s)
Herbicidas , Pirólisis , Glicina/análogos & derivados , Incineración , Glifosato
9.
Chemosphere ; 225: 209-216, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30877915

RESUMEN

This paper examines the gas phase thermal decomposition of dieldrin and associated formation of toxic combustion products including polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F). Volatile Organic Carbon (VOC) analysis revealed the formation of pentachlorostyrene (PCS), hexachlorostyrene (HCS) and polychlorinated naphthalene as toxic combustion products generated during the combustion of dieldrin. The thermal pyrolysis of dieldrin resulted in the formation of chlorinated benzenes and chlorinated phenols, which are known PCDD/F precursors. The formation of PCDD/F commenced around 823 K @ 5s residence time and results indicate a preference for the formation of PCDF over PCDD under all experimental conditions studied. Subsequent experiments, to examine the yield of PCDD/F as a function of temperature, reveal the progressive chlorination of PCDD/F with temperatures up to 923 K. Octachlorodibenzofuran (OCDF) was the major dioxin congener detected in the oxidation of dieldrin. The highest toxicity factor for dioxin formation was recorded at 923 K with a 6% O2 content in the feed gas and corresponds to 6.24 ng TEQ WHO 2005/mg of dieldrin and total PCDD/F concentration of 96.8 ng/mg of dieldrin.


Asunto(s)
Dibenzofuranos Policlorados/química , Dieldrín/química , Dibenzodioxinas Policloradas/química , Temperatura , Dibenzofuranos Policlorados/toxicidad , Oxidación-Reducción , Dibenzodioxinas Policloradas/toxicidad
10.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1864(7): 985-1004, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30910689

RESUMEN

Liver fatty acid binding protein (L-FABP) is the major fatty acid binding/"chaperone" protein in hepatic cytosol. Although fatty acids can be derived from the breakdown of dietary fat and glucose, relatively little is known regarding the impact of L-FABP on phenotype in the context of high dietary glucose. Potential impact was examined in wild-type (WT) and Lfabp gene ablated (LKO) female mice fed either a control or pair-fed high glucose diet (HGD). WT mice fed HGD alone exhibited decreased whole body weight gain and weight gain/kcal food consumed-both as reduced lean tissue mass (LTM) and fat tissue mass (FTM). Conversely, LKO alone increased weight gain, lean tissue mass, and fat tissue mass while decreasing serum ß-hydroxybutyrate (indicative of hepatic fatty acid oxidation)-regardless of diet. Both LKO alone and HGD alone significantly altered the serum lipoprotein profile and increased triacylglycerol (TG), but in HGD mice the LKO did not further exacerbate serum TG content. HGD had little effect on hepatic lipid composition in WT mice, but prevented the LKO-induced selective increase in hepatic phospholipid, free-cholesterol and cholesteryl-ester. Taken together, these findings suggest that high glucose diet diminished the effects of LKO on the whole body and lipid phenotype of these mice.


Asunto(s)
Proteínas de Unión a Ácidos Grasos/deficiencia , Glucosa/farmacología , Metabolismo de los Lípidos , Animales , Colesterol/metabolismo , Dieta , Proteínas de Unión a Ácidos Grasos/genética , Femenino , Hígado/metabolismo , Ratones , Fosfolípidos/metabolismo , Triglicéridos/metabolismo , Aumento de Peso
11.
Environ Sci Technol ; 52(13): 7327-7333, 2018 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-29846064

RESUMEN

Thermal decomposition of the pesticide, chlorpyrifos (CPf) and its major degradation product, 3,5,6-trichloro-2-pyridinol (TCpyol), has been studied by quantum chemical calculation using density functional methods at the M06-2X/GTLarge//M06-2 X/6-31+G(d,p) level of theory. Chlopyrifos was found to undergo a series of unimolecular stepwise elimination reactions releasing two molecules of ethylene and finally HOPOS to form TCpyol. TCpyol underwent oxidative decomposition initiated by abstraction of its phenolic H atom by O2. Two phenoxy radicals so produced underwent combination leading to the formation of 2,3,7,8-tetrachloro-[1,4]dioxinodipyridine (TCDDpy). Via Smiles rearrangement both cis and trans TCDDpy are formed. Kinetic models have been constructed to model the decomposition of CPf into TCpyol and of the latter into cis and trans TCDDpy. Modeled results are compared with the experiments of Sakiyama et al. ( Organohalogen Compounds, 2012, 74, 1441-1444).


Asunto(s)
Cloropirifos , Dioxinas , Plaguicidas , Dibenzodioxinas Policloradas , Cinética
12.
Vet Med Sci ; 4(1): 53-62, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29468081

RESUMEN

Cutaneous pigmented viral plaques is a disorder of epidermal growth caused by canine papillomavirus type 4 (CPV-4). There is currently no standard of care for managing this condition and it has not been reported in the Hungarian Vizsla. This case series documents the clinical features of canine pigmented viral plaques in Hungarian Vizsla dogs and the treatment of a severe case using a novel topical agent tigilanol tiglate (EBC-46). A 4-year-old spayed Hungarian Vizsla in Australia was presented for multiple cutaneous pigmented plaques extending from the ventral cervical region. Lesions were neither painful nor pruritic. The number and size of these sessile plaques increased over time, with the largest lesions eventually taking on an exophytic (wart-like) appearance. These lesions did not affect the dog's wellbeing. Two much less severe cases in a 5-year-old Vizsla from the UK and a 7-year-old Vizsla from New Zealand were also diagnosed. Histology was consistent with papillomavirus-induced pigmented plaques and CPV-4 DNA sequences were amplified from paraffin-embedded formalin-fixed tissue using the polymerase chain reaction from the most severely affected patient. Topical imiquimod was ineffective although used for only a short time. Two topical applications of novel anti-neoplastic diterpene ester tigilanol tiglate as a gel, 9 days apart, greatly reduced the size and number of lesions in a limited portion of skin treated, over the lateral hock. While CPV-4 has been previously reported to cause pigmented plaques, most commonly on pug dogs, but sporadically on other breeds, this is the first report of this virus causing plaques in Hungarian Vizslas. The cases illustrate some of the difficulties in diagnosing papillomavirus-induced disease in dogs, especially in its early stages. Topical tigilanol tiglate is a potentially useful topical therapy for this viral-induced disorder of cell growth and represents a treatment deserving of further investigation.

13.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1863(3): 323-338, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29307784

RESUMEN

Although singly ablating Fabp1 or Scp2/Scpx genes may exacerbate the impact of high fat diet (HFD) on whole body phenotype and non-alcoholic fatty liver disease (NAFLD), concomitant upregulation of the non-ablated gene, preference for ad libitum fed HFD, and sex differences complicate interpretation. Therefore, these issues were addressed in male and female mice ablated in both genes (Fabp1/Scp2/Scpx null or TKO) and pair-fed HFD. Wild-type (WT) males gained more body weight as fat tissue mass (FTM) and exhibited higher hepatic lipid accumulation than WT females. The greater hepatic lipid accumulation in WT males was associated with higher hepatic expression of enzymes in glyceride synthesis, higher hepatic bile acids, and upregulation of transporters involved in hepatic reuptake of serum bile acids. While TKO had little effect on whole body phenotype and hepatic bile acid accumulation in either sex, TKO increased hepatic accumulation of lipids in both, specifically phospholipid and cholesteryl esters in males and females and free cholesterol in females. TKO-induced increases in glycerides were attributed not only to complete loss of FABP1, SCP2 and SCPx, but also in part to sex-dependent upregulation of hepatic lipogenic enzymes. These data with WT and TKO mice pair-fed HFD indicate that: i) Sex significantly impacted the ability of HFD to increase body weight, induce hepatic lipid accumulation and increase hepatic bile acids; and ii) TKO exacerbated the HFD ability to induce hepatic lipid accumulation, regardless of sex, but did not significantly alter whole body phenotype in either sex.


Asunto(s)
Proteínas Portadoras/metabolismo , Colesterol/metabolismo , Grasas de la Dieta/efectos adversos , Proteínas de Unión a Ácidos Grasos/metabolismo , Hígado/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Fosfolípidos/metabolismo , Animales , Proteínas Portadoras/genética , Colesterol/genética , Grasas de la Dieta/farmacología , Proteínas de Unión a Ácidos Grasos/genética , Femenino , Hígado/patología , Masculino , Ratones , Ratones Noqueados , Enfermedad del Hígado Graso no Alcohólico/inducido químicamente , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/patología , Fosfolípidos/genética
14.
J Lipid Res ; 58(11): 2114-2126, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28972119

RESUMEN

Upregulation of the hepatic endocannabinoid (EC) receptor [cannabinoid receptor-1 (CB1)] and arachidonoylethanolamide (AEA) is associated with nonalcoholic fatty liver disease (NAFLD). Male mice fed high-fat diet (HFD) ad libitum also exhibit NAFLD, increased hepatic AEA, and obesity. But, preference for HFD complicates interpretation and almost nothing is known about these effects in females. These issues were addressed by pair-feeding HFD. Similarly to ad libitum-fed HFD, pair-fed HFD also increased WT male and female mouse fat tissue mass (FTM), but preferentially at the expense of lean tissue mass. In contrast, pair-fed HFD did not elicit NAFLD in WT mice regardless of sex. Concomitantly, pair-fed HFD oppositely impacted hepatic AEA, 2-arachidonoyl glycerol, and/or CB1 in WT males versus females. In pair-fed HFD mice, liver FA binding protein-1 (Fabp1) gene ablation (LKO): i) exacerbated FTM in both sexes; ii) did not elicit liver neutral lipid accumulation in males and only slightly in females; iii) increased liver AEA in males, but decreased it in females; and iv) decreased CB1 only in males. Thus, pair-fed HFD selectively impacted hepatic ECs more in females, but did not elicit NAFLD in either sex. These effects were modified by LKO consistent with FABP1's ability to impact EC and FA metabolism.


Asunto(s)
Dieta Alta en Grasa/efectos adversos , Endocannabinoides/metabolismo , Proteínas de Unión a Ácidos Grasos/deficiencia , Proteínas de Unión a Ácidos Grasos/genética , Técnicas de Inactivación de Genes , Hígado/efectos de los fármacos , Hígado/metabolismo , Animales , Transporte Biológico/efectos de los fármacos , Transporte Biológico/genética , Biomarcadores/sangre , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Citosol/efectos de los fármacos , Citosol/metabolismo , Ácidos Grasos/metabolismo , Femenino , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/genética , Lipogénesis/efectos de los fármacos , Lipogénesis/genética , Hígado/citología , Masculino , Ratones , Ratones Endogámicos C57BL , Tamaño de los Órganos/efectos de los fármacos , Tamaño de los Órganos/genética , Fenotipo , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética
15.
Front Pharmacol ; 8: 493, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28798688

RESUMEN

Chronic low back pain (LBP), the leading cause of disability globally, is notoriously difficult to treat. Most rodent models of LBP mimic lumbar radicular pain rather than mechanical LBP. Here, we describe establishment of a new rat model of mechanical LBP that is devoid of a neuropathic component. Groups of adult male Sprague Dawley rats were anesthetized and their lumbar L4/L5 and L5/L6 intervertebral disks (IVDs) were punctured (0.5 mm outer diameter, 2mm-deep) 5 (LPB-5X), or 10 (LBP-10X) times per disk. Sham-rats underwent similar surgery, but without disk puncture. Baseline noxious pressure hyperalgesia of lumbar axial deep tissues, mechanical allodynia in the hindpaws and gait were assessed prior to surgery and once-weekly until study completion on day 49. The model was also characterized using pharmacologic and histologic methods. Good animal health was maintained for ≥ 49 days post-surgery. For LBP- but not sham-rats, there was temporal development of noxious pressure hyperalgesia in lumbar axial deep tissues at days 14-49 post-surgery. Importantly, there were no between-group differences in von Frey paw withdrawal thresholds or gait parameters until study completion. On day 49, significant histologic changes were observed in the L4/L5 and L5/L6 IVDs for LBP-10X rats, but not sham-rats. In LBP-10X rats, single bolus doses of morphine produced dose-dependent relief of primary and secondary mechanical hyperalgesia in lumbar axial deep tissues at L4/L5 and L1, respectively. In conclusion, our new rat model has considerable potential for providing novel insight on the pathobiology of mechanical LBP and for analgesic efficacy assessment of novel compounds.

16.
J Phys Chem A ; 121(31): 5871-5883, 2017 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-28682607

RESUMEN

Thermal decomposition of hexachlorocyclopentadiene (HCCP) has been studied in inert gas and under oxidative conditions in a silica flow reactor at a residence time of 5.0 s between 690 and 923 K and 1 atm pressure. Pyrolysis was initiated by Cl bond fission to form pentachlorocyclopentadienyl radical; two such radicals then combined to undergo a series of intramolecular rearrangements and Cl fissions, producing principally octachloronaphthalene (8ClNP) and Cl2. This process has been studied by quantum chemical calculation, and a reaction potential energy surface has been developed. The rate constant of initial Cl atom fission has been calculated by canonical variational transition state theory as k = 1.45 × 1015 exp(-222 ± 9 kJ mol-1/RT) s-1 between 500 and 2000 K. A minimal kinetic model was developed to model the decomposition and major products. Oxidative decomposition was studied in nitrogen with O2 contents of 1, 6, 12, and 20 mol %. Increasing O2 to 6-8% increased the rate of decomposition of HCCP and decreased the yield of 8ClNP. Above 823 K, hexachlorobenzene (HCB) and CO became major products. The oxidative reaction has also been studied quantum chemically. At high O2 content (>∼10%), the rate of decomposition of HCCP declined as did yields of 8ClNP and HCB, but CO yields increased.

17.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1862(3): 291-304, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27940000

RESUMEN

In vitro studies suggest that liver fatty acid binding protein (L-FABP) and sterol carrier protein-2/sterol carrier protein-x (SCP2/SCPx) gene products facilitate uptake and metabolism and detoxification of dietary-derived phytol in mammals. However, concomitant upregulation of L-FABP in SCP2/SCPx null mice complicates interpretation of their physiological phenotype. Therefore, the impact of ablating both the L-FABP gene and SCP2/SCPx gene (L-FABP/SCP2/SCPx null or TKO) was examined in phytol-fed female wild-type (WT) and TKO mice. TKO increased hepatic total lipid accumulation, primarily phospholipid, by mechanisms involving increased hepatic levels of proteins in the phospholipid synthetic pathway. Concomitantly, TKO reduced expression of proteins in targeting fatty acids towards the triacylglycerol synthetic pathway. Increased hepatic lipid accumulation was not associated with any concomitant upregulation of membrane fatty acid transport/translocase proteins involved in fatty acid uptake (FATP2, FATP4, FATP5 or GOT) or cytosolic proteins involved in fatty acid intracellular targeting (ACBP). In addition, TKO exacerbated dietary phytol-induced whole body weight loss, especially lean tissue mass. Since individually ablating SCPx or SCP2/SCPx elicited concomitant upregulation of L-FABP, these findings with TKO mice help to resolve the contributions of SCP2/SCPx gene ablation on dietary phytol-induced whole body and hepatic lipid phenotype independent of concomitant upregulation of L-FABP.


Asunto(s)
Proteínas Portadoras/metabolismo , Proteínas de Unión a Ácidos Grasos/metabolismo , Metabolismo de los Lípidos/efectos de los fármacos , Fitol/administración & dosificación , Animales , Dieta/métodos , Ácidos Grasos/metabolismo , Femenino , Lípidos/fisiología , Hígado/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fosfolípidos/metabolismo , Triglicéridos/metabolismo , Regulación hacia Arriba/efectos de los fármacos
18.
Environ Sci Technol ; 50(18): 10106-13, 2016 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-27570874

RESUMEN

This paper investigates the thermal decomposition of technical endosulfan under oxidative conditions and the subsequent formation of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/F, dioxins), and their precursors. Both quantum chemical calculations and laboratory experiments were employed to investigate the pathways of oxidation of endosulfan. The laboratory scale apparatus used consists of a tubular reactor and product collection system and analysis train. The results report the effect of temperature (523-923 K) and O2 concentration on PCDD/F formation in a N2 bath gas at a residence time of 5 s. The decomposition of endosulfan produces two types of PCDD/F precursors, involving all chlorinated benzenes (CBz) and chlorinated phenols (CPh). Oxidation of endosulfan favors the formation of PCDF over PCDD. Octachlorodibenzofuran is the most abundant homologue group detected in all experiments. The maximum emission factor for PCDD/F was observed at 923 K and O2 content of 6% and corresponds to 64 ng TEQ-WHO2005 per mg of endosulfan and a total dioxin concentration of 1131 ng/mg of endosulfan.


Asunto(s)
Endosulfano , Dibenzodioxinas Policloradas , Dibenzofuranos , Dioxinas , Oxidación-Reducción
19.
Vet Parasitol ; 223: 214-21, 2016 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-27198803

RESUMEN

Little is known about the genetic diversity and pathogenicity of trypanosomes in Australian bats. Recently a novel trypanosome species was identified in an adult female little red flying fox (Pteropus scapulatus) with clinical and pathological evidence of trypanosomosis. The present study used morphology and molecular methods to demonstrate that this trypanosome is a distinct species and we propose the name Trypanosoma teixeirae sp. n. Morphological comparison showed that its circulating trypomastigotes were significantly different from those of Trypanosoma pteropi and Trypanosoma hipposideri, two species previously described from Australian bats. Genetic information was not available for T. pteropi and T. hipposideri but phylogenetic analyses at the 18S ribosomal RNA (rRNA) and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) loci indicated that T. teixeirae sp. n. was genetically distinct and clustered with other bat-derived trypanosome species within the Trypanosoma cruzi clade.


Asunto(s)
Quirópteros/parasitología , Trypanosoma/clasificación , Tripanosomiasis/veterinaria , Animales , Australia/epidemiología , ADN Protozoario/genética , Femenino , Regulación Enzimológica de la Expresión Génica , Gliceraldehído-3-Fosfato Deshidrogenasas/genética , Filogenia , ARN Protozoario/genética , ARN Ribosómico 18S/genética , Especificidad de la Especie , Trypanosoma/genética , Trypanosoma/aislamiento & purificación , Tripanosomiasis/epidemiología , Tripanosomiasis/parasitología
20.
J Feline Med Surg ; 17(11): 954-63, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26486982

RESUMEN

OF CASES: A 6-month-old Burmese kitten developed focal skin lesions following a routine ovariohysterectomy. These were eventually attributed to the patient struggling during catheter placement and induction of anaesthesia. The lesions were caused by fluid extravasation in the subcutis and ischaemic necrosis of the overlying dermis, giving rise to an eschar-like appearance. Such lesions have been seen previously in Burmese cats with cutaneous asthenia and it is thought that they arise due to poor collagenous support for dermal blood vessels. An increased skin extensibility index (>23%) supported a diagnosis of cutaneous asthenia (Ehlers-Danlos-like syndrome), which has been reported as an inherited condition of Burmese cats in Australia, New Zealand and Europe. An additional Burmese cat with cutaneous asthenia is presented in detail, with lifetime follow-up and further salient observations by the owner, a veterinarian. Photographs of three other affected Burmese cats are provided to illustrate the range of presentations encountered with this condition. All five affected cats were presented with eschars, atrophic alopecia and increased skin extensibility, while one cat also had skin ulcers. Routine histopathological examination, including use of special stains such as trichrome, was unhelpful in establishing the diagnosis. CLINICAL REVIEW: The clinical features of this genetic disease of Burmese cats are reviewed, especially in relation to the postulated 'vasculopathy' that gives rise to characteristic skin lesions. Long term management of this condition is discussed briefly.


Asunto(s)
Anestesia/efectos adversos , Astenia/veterinaria , Enfermedades de los Gatos/diagnóstico , Enfermedades de los Gatos/etiología , Síndrome de Ehlers-Danlos/veterinaria , Anestesia/veterinaria , Animales , Astenia/diagnóstico , Astenia/etiología , Gatos , Síndrome de Ehlers-Danlos/diagnóstico , Síndrome de Ehlers-Danlos/etiología , Femenino , Ovariectomía/efectos adversos , Piel/patología
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