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1.
Vet Res ; 55(1): 69, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38822400

RESUMO

Current diagnostic methods for Johne's disease in cattle allow reliable detection of infections with Mycobacterium avium ssp. paratuberculosis (MAP) not before animals are 2 years of age. Applying a flow cytometry-based approach (FCA) to quantify a MAP-specific interferon-gamma (IFN-γ) response in T cell subsets, the present study sought to monitor the kinetics of the cell-mediated immune response in experimentally infected calves. Six MAP-negative calves and six calves, orally inoculated with MAP at 10 days of age, were sampled every 4 weeks for 52 weeks post-inoculation (wpi). Peripheral blood mononuclear cells (PBMC) were stimulated with either purified protein derivatives (PPD) or whole cell sonicates derived from MAP (WCSj), M. avium ssp. avium or M. phlei for 6 days followed by labeling of intracellular IFN-γ in CD4+ and CD8+ T cells. No antigen-specific IFN-γ production was detectable in CD8+ cells throughout and the responses of CD4+ cells of MAP-infected and control calves were similar up to 12 wpi. However, the mean fluorescence intensity (MFI) for the detection of IFN-γ in CD4+ cells after WCSj antigen stimulation allowed for a differentiation of animal groups from 16 wpi onwards. This approach had a superior sensitivity (87.8%) and specificity (86.8%) to detect infected animals from 16 wpi onwards, i.e., in an early infection stage, as compared to the IFN-γ release assay (IGRA). Quantification of specific IFN-γ production at the level of individual CD4+ cells may serve, therefore, as a valuable tool to identify MAP-infected juvenile cattle.


Assuntos
Linfócitos T CD4-Positivos , Doenças dos Bovinos , Citometria de Fluxo , Interferon gama , Mycobacterium avium subsp. paratuberculosis , Paratuberculose , Animais , Bovinos , Paratuberculose/imunologia , Paratuberculose/diagnóstico , Paratuberculose/microbiologia , Mycobacterium avium subsp. paratuberculosis/imunologia , Mycobacterium avium subsp. paratuberculosis/fisiologia , Interferon gama/metabolismo , Citometria de Fluxo/veterinária , Citometria de Fluxo/métodos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/microbiologia , Linfócitos T CD4-Positivos/imunologia , Biomarcadores
2.
J Comput Chem ; 44(2): 65-75, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36264287

RESUMO

The ferromagnetic and antiferromagnetic wave functions of the KMnF3 perovskite have been evaluated quantum-mechanically by using an all electron approach and, for comparison, pseudopotentials on the transition metal and the fluorine ions. It is shown that the different number of α and ß electrons in the d shell of Mn perturbs the inner shells, with shifts between the α and ß eigenvalues that can be as large as 6 eV for the 3s level, and is far from negligible also for the 2s and 2p states. The valence electrons of F are polarized by the majority spin electrons of Mn, and in turn, spin polarize their 1s electrons. When a pseudopotential is used, such a spin polarization of the core functions of Mn and F can obviously not take place. The importance of such a spin polarization can be appreciated by comparing (i) the spin density at the Mn and F nuclear position, and then the Fermi contact constant, a crucial quantity for the hyperfine coupling, and (ii) the ferromagnetic-antiferromagnetic energy difference, when obtained with an all electron or a pseudopotential scheme, and exploring how the latter varies with pressure. This difference is as large as 50% of the all electron datum, and is mainly due to the rigid treatment of the F ion core. The effect of five different functionals on the core spin polarization is documented.

3.
Phys Chem Chem Phys ; 25(18): 12961-12973, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37099190

RESUMO

The relative stability of various phases of five AVF3 compounds (A = Li, Na, K, Rb and Cs) is investigated starting from the cubic (C) Pm3̄m (221) prototype structure, with five atoms (one formula unit) in the primitive cell. To the authors' knowledge, only three of these compounds have been investigated experimentally (Na, K and Rb), and they are reported as being cubic. The picture emerging from the present simulation is quite different: CsVF3 and RbVF3 are dynamically stable in the cubic structure, KVF3 is tetragonal, with space group (SG) I4/mcm (no. 140) and 10 atoms in the unit cell; note, however, that an orthorhombic Pnma (62) phase (four formula units) exists, which is not a subgroup of I4/mcm (140), and is very close in energy to the tetragonal phase. Further symmetry lowering is observed in the Na and Li compounds that are orthorhombic. The energy gain and volume reduction with respect to the cubic aristotype increase along the series K, Na and Li, and is very large for the last two compounds. Both FM and AFM solutions have been explored, and they show a very similar path along the SG modifications. The present scheme for determining the lowest energy SG is general, and can be applied to any perovskite. The B3LYP full range hybrid functional and the Hartree-Fock (HF) Hamiltonian, an all-electron Gaussian type basis set and the CRYSTAL code have been used.

4.
Phys Chem Chem Phys ; 24(21): 12950-12960, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35609269

RESUMO

In many recent papers devoted to first row transition metal fluorides and oxides, not much attention is devoted to the spin density, a crucial quantity for the determination of the superexchange mechanism, and then for the ferro-antiferromagnetic energy difference. Usually, only the eigenvalues of the system are represented, in the form of band structures or, more frequently, of density of states (DOS). When discussing the orbital ordering and the Jahn-Teller effect, simple schemes with cubes and lobes are used to illustrate the shape of the d occupancy. But the eigenvectors, and the resulting spin density function, as obtained from the calculations, are rarely shown. When represented, only a fuzzy shape that recalls the d orbital shape can be observed. On the basis of these considerations, spin density maps for 5 compounds of the KMF3 (M from Mn to Cu) family have been produced, which clearly illustrate which d orbital is singly or doubly occupied. At variance with respect to the near totality of the papers devoted to these systems, we use an all electron scheme, a Gaussian type basis set, and the Hartree-Fock Hamiltonian or the B3LYP hybrid functional (the resulting maps turn out to be very similar, in the scale used for our figures). The spin density in the five cases can easily be interpreted in terms of the shape of the d orbitals as appearing in textbooks.

5.
J Chem Phys ; 152(14): 144107, 2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32295355

RESUMO

Molpro is a general purpose quantum chemistry software package with a long development history. It was originally focused on accurate wavefunction calculations for small molecules but now has many additional distinctive capabilities that include, inter alia, local correlation approximations combined with explicit correlation, highly efficient implementations of single-reference correlation methods, robust and efficient multireference methods for large molecules, projection embedding, and anharmonic vibrational spectra. In addition to conventional input-file specification of calculations, Molpro calculations can now be specified and analyzed via a new graphical user interface and through a Python framework.

6.
J Chem Phys ; 152(20): 204111, 2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32486670

RESUMO

CRYSTAL is a periodic ab initio code that uses a Gaussian-type basis set to express crystalline orbitals (i.e., Bloch functions). The use of atom-centered basis functions allows treating 3D (crystals), 2D (slabs), 1D (polymers), and 0D (molecules) systems on the same grounds. In turn, all-electron calculations are inherently permitted along with pseudopotential strategies. A variety of density functionals are implemented, including global and range-separated hybrids of various natures and, as an extreme case, Hartree-Fock (HF). The cost for HF or hybrids is only about 3-5 times higher than when using the local density approximation or the generalized gradient approximation. Symmetry is fully exploited at all steps of the calculation. Many tools are available to modify the structure as given in input and simplify the construction of complicated objects, such as slabs, nanotubes, molecules, and clusters. Many tensorial properties can be evaluated by using a single input keyword: elastic, piezoelectric, photoelastic, dielectric, first and second hyperpolarizabilities, etc. The calculation of infrared and Raman spectra is available, and the intensities are computed analytically. Automated tools are available for the generation of the relevant configurations of solid solutions and/or disordered systems. Three versions of the code exist: serial, parallel, and massive-parallel. In the second one, the most relevant matrices are duplicated on each core, whereas in the third one, the Fock matrix is distributed for diagonalization. All the relevant vectors are dynamically allocated and deallocated after use, making the code very agile. CRYSTAL can be used efficiently on high performance computing machines up to thousands of cores.

7.
Chemistry ; 25(33): 7921-7926, 2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-30972829

RESUMO

The admixture of CeO2 , Ce, CeCl3 , and MoO3 with an excess of LiCl as flux in evacuated silica ampules leads to large black single crystals as well as a black microcrystalline powder of Ce3 Cl3 [MoO6 ] after tempering at 850 °C for three days. The title compound crystallizes in the hexagonal space group P63 /m (a=934.93(4), c=538.86(2) pm) with two formula units per unit cell. The crystal structure consists of rather unusual trigonal-prismatic [MoO6 ]6- units besides Ce3+ ions in a tetra-capped trigonal-prismatic coordination, formed by four Cl- and six O2- ions. The black color is related to an optical band gap of 1.35(2) eV, which was determined by diffuse reflectance spectroscopy and confirmed by theoretical calculations. The low band gap between the 4f1 state of cerium (HOMO) and the 5d0 state of molybdenum (LUMO) gave rise to the idea of electronic excitation between these two states by IR irradiation, creating a drop in the resistivity of the material, which was detected by appropriate measurements.

8.
Inorg Chem ; 56(17): 10644-10654, 2017 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-28836771

RESUMO

Barium sulfide (BaS) is an important precursor to other barium compounds with applications from ceramics and flame retardants to luminous paints and additives, and recent research shows potential technological applications in electrical and optical devices. Under normal conditions, BaS crystallizes in the NaCl type of structure, and with the increase in pressure BaS undergoes a structural phase transition to a CsCl type modification. This study presents modeling of barium sulfide under pressure with special focus on structural aspects and electronic properties. We predict metastable BaS polymorphs which have not yet been observed in the experiment or in previous calculations, and we investigated their vibrational and thermodynamical properties. Furthermore, we investigate the electronic properties of experimentally known structures as well as novel predicted modifications of BaS on ab initio level using Hartree-Fock, GGA-PBE, and the hybrid B3LYP functional. In this way, we address new possibilities of synthesizing BaS and possible band gap tuning which can have great applications in optoelectrical technologies.

9.
Phys Chem Chem Phys ; 16(42): 23412-20, 2014 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-25264622

RESUMO

Using first principles density functional theory (DFT), the electronic and magnetic properties as well as the Li-ion migration in LiCoO2 have been studied with a gradient corrected functional. The magnetic properties were also investigated in addition using a gradient corrected functional in combination with an on-site repulsion U and a hybrid functional. We find LiCoO2 to be non-magnetic under ambient conditions. A magnetic ground state can be obtained by a volume expansion corresponding to a negative pressure of -8 GPa due to a competition between Hund's rules favoring magnetism on the Co(3+) ions and the crystal field splitting, which suppresses magnetism at zero pressure. The barrier for lithium transport is determined to be 0.44 eV from nudged elastic band (NEB) calculations on the Li0.917CoO2 system.

10.
Chemistry ; 18(35): 10929-36, 2012 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-22807350

RESUMO

Recently, we have investigated the energy landscape of PbS for many different pressures on the ab initio level by using Hartree-Fock and density functional theory to globally search for possible thermodynamically stable and metastable structures. The perhaps most fascinating observation was that besides the experimentally known modification exhibiting the rock salt structure a second minimum exists close-by on the landscape showing the low-temperature α-GeTe-type structure. In the present study, we investigate the possible reasons for the existence of this metastable modification; in particular we address the question, whether the α-GeTe-type modification might be stabilized (and conversely the rock salt modification destabilized) by steric effects of the non-bonding electron pair.

11.
J Chem Phys ; 136(7): 074106, 2012 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-22360235

RESUMO

Finite-cluster calculations employing high-level wavefunction-based ab initio methods and extended atomic-orbital basis sets are used to determine local energy increments for bulk LiH. It is shown that these increments can be converged with respect to cluster size and point-charge embedding so as to yield bulk cohesive energies with an accuracy of better than 1 mE(h), both at the Hartree-Fock and at correlated levels. Instrumental for the efficiency of the scheme is the introduction of non-orthogonal orbitals, at an intermediate stage.

12.
Microbiology (Reading) ; 157(Pt 2): 557-565, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21051485

RESUMO

Bovine Johne's disease (paratuberculosis), caused by Mycobacterium avium subspecies paratuberculosis, poses a significant economic problem to the beef and dairy industry worldwide. Despite its relevance, however, pathogenesis of Johne's disease is still only partially resolved. Since mycobacterial membrane proteins expressed during infection are likely to play an important role in pathogenesis, membrane-enriched fractions, namely mucosa-derived membranes (MDM) and culture-derived membranes (CDM), of M. avium subsp. paratuberculosis from three cows with clinical paratuberculosis were investigated. An initial analysis by 2D difference gel electrophoresis (2D DIGE) and MALDI-TOF-MS analysis revealed four differentially expressed proteins with only one predicted membrane protein. Due to this limited outcome, membrane preparations were subjected to a tube-gel trypsin digestion and investigated by using nanoflow-liquid-chromatography-coupled tandem MS. Based on this approach a total of 212 proteins were detected in MDM including 32 proteins of bovine origin; 275 proteins were detected in CDM; 59 % of MDM and CDM proteins were predicted to be membrane-associated. A total of 130 of the proteins were detected in both MDM and CDM and 48 predicted membrane proteins were detected in MDM from at least two cows. Four of these proteins were not detected in CDM, implying differential expression in the host. All membrane-associated proteins, especially the four identified as being differentially expressed, might be relevant targets for further analyses into the pathogenesis of bovine paratuberculosis.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Membrana/metabolismo , Mycobacterium avium subsp. paratuberculosis/metabolismo , Paratuberculose/microbiologia , Proteoma/metabolismo , Animais , Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana , Bovinos , Doenças dos Bovinos/microbiologia , Eletroforese em Gel Bidimensional , Mucosa Intestinal/microbiologia , Proteínas de Membrana/genética , Mycobacterium avium subsp. paratuberculosis/genética , Mycobacterium avium subsp. paratuberculosis/isolamento & purificação , Polimorfismo de Fragmento de Restrição , Proteômica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em Tandem
13.
Vet Res ; 42: 97, 2011 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-21878124

RESUMO

A mysterious disease affecting calves, named bovine neonatal pancytopenia (BNP), emerged in 2007 in several European countries. Epidemiological studies revealed a connection between BNP and vaccination with an inactivated vaccine against bovine virus diarrhea (BVD). Alloantibodies reacting with blood leukocytes of calves were detected in serum and colostrum of dams, which have given birth to calves affected by BNP. To understand the linkage between vaccination and the development of alloantibodies, we determined the antigens reacting with these alloantibodies. Immunoprecipitation of surface proteins from bovine leukocytes and kidney cells using sera from dams with a confirmed case of BNP in their gestation history reacted with two dominant protein species of 44 and 12 kDa. These proteins were not detected by sera from dams, free of BVDV and not vaccinated against BVD, and from sera of animals vaccinated with a different inactivated BVD vaccine. The 44 kDa protein was identified by mass spectrometry analysis as MHC I, the other as ß-2-microglobulin. The presence of major histocompatibility complex class I (MHC I) in the vaccine was confirmed by Western blot using a MHC I specific monoclonal antibody. A model of BNP pathogenesis is proposed.


Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/imunologia , Doenças dos Bovinos/imunologia , Vírus da Diarreia Viral Bovina/imunologia , Pancitopenia/veterinária , Vacinas Virais/imunologia , Sequência de Aminoácidos , Animais , Animais Recém-Nascidos , Anticorpos Antivirais/sangue , Antígenos Virais/sangue , Western Blotting/veterinária , Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Bovinos , Doenças dos Bovinos/virologia , Colostro/metabolismo , Feminino , Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/metabolismo , Imunoprecipitação/veterinária , Isoanticorpos/sangue , Rim/imunologia , Rim/virologia , Leucócitos/imunologia , Leucócitos/virologia , Espectrometria de Massas/veterinária , Pancitopenia/imunologia , Pancitopenia/virologia , Mapeamento de Peptídeos/veterinária , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Vacinas Virais/administração & dosagem , Microglobulina beta-2/química , Microglobulina beta-2/genética , Microglobulina beta-2/metabolismo
14.
J Vet Diagn Invest ; 21(5): 719-21, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19737773

RESUMO

The current report describes a case of congenital subcutaneous and intramuscular tumors of the neck and tail base in a 4-week-old female Angus-Charolais crossbred calf. Results of clinical and ultrasound examination are summarized. Biopsy and necropsy findings indicated an infiltrative lipoma. Congenital lipomas are uncommon tumors in bovids. Clinical and morphologic differentials, as well as classification and the possible pathogenesis of congenital neoplasms, are discussed.


Assuntos
Lipoma/veterinária , Adipócitos/patologia , Animais , Animais Recém-Nascidos , Biópsia , Bovinos , Eutanásia , Feminino , Neoplasias de Cabeça e Pescoço/congênito , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/veterinária , Ligamentos/patologia , Lipoma/congênito , Lipoma/diagnóstico por imagem , Lipoma/patologia , Radiografia , Ultrassonografia
15.
Vet J ; 181(2): 90-6, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18397836

RESUMO

Impaired abomasal motility and an increased accumulation of gas are prerequisites for displacement of the abomasum in the cow. Predisposing factors are the breed (e.g. Holstein-Friesian, Simmental-Red-Holstein cross breeds and Guernsey), genetic background, twin pregnancy, first weeks of lactation, metabolic disorders (ketosis, increased lipomobilisation, insulin resistance), high-concentrate and low-fibre diets, as well as other concomitant diseases, such as endometritis, mastitis and claw disorders. There does not appear to be a strong correlation between increased milk yield or endotoxaemia and abomasal displacement. Recent studies have focused on possible functional disorders of the enteric nervous system within the abomasal wall, since cattle with abomasal displacement have an increased activity of neuronal nitric oxide synthase, as well as decreased acetylcholine sensitivity. In addition, there appear to be significant differences between breeds in the levels of the neurotransmitters substance P (SP) and vasoactive intestinal peptide (VIP) in the abomasal wall. For example, SP (stimulatory) was significantly less in German Holsteins in comparison to the German Fleckvieh, whereas VIP (inhibitory) was markedly increased. These risk factors may explain why Holstein cows are more susceptible to abomasal displacement than other breeds.


Assuntos
Abomaso/patologia , Abomaso/inervação , Animais , Bovinos/genética , Indústria de Laticínios , Feminino , Masculino , Doenças Metabólicas/complicações , Doenças Metabólicas/patologia , Doenças Metabólicas/veterinária , Sistema Nervoso Parassimpático/patologia , Gravidez , Complicações na Gravidez/patologia , Complicações na Gravidez/veterinária , Sistema Nervoso Simpático/patologia
16.
Open Vet J ; 9(2): 177-184, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31360659

RESUMO

Background: Iron deficiency can cause anemia in calves and is, therefore, of economic importance for the cattle industry. Low iron levels are commonly caused by feeding whole milk without the addition of dietary supplements and led to the most frequent cause of anemia in calves. Other reasons for the development of anemia include congenital iron deficiency, malnutrition, bleeding ulcers, or bloodsucking parasites. Aim: This study compared laboratory parameters that are commonly used to diagnose iron deficiency anemia in calves. Additionally, serum ferritin values were compared amongst calves fed different milk meals. Methods: For this purpose, blood samples from 40 calves were analyzed for different hematologic parameters as well as the content of copper, glutathione peroxidase, serum iron, and serum ferritin. Results: Eight calves showed decreased hemoglobin and hematocrit values and a significantly lower number of erythrocytes compared with non-anemic calves. Interestingly, 19 of 40 calves had a low serum iron. Considering their serum ferritin levels, only 14 calves, including six calves with both low iron and low ferritin levels, were classified as iron deficient. No direct correlation between serum ferritin and serum iron was detected. Comparing milk diets, more calves fed milk replacer showed reduced levels of ferritin compared with calves fed whole milk. Conclusion: Our data indicate that the determination of hemoglobin and serum iron is of limited suitability for the diagnosis of iron deficiency in calves. We suggest that the determination of serum ferritin should be the preferred parameter, since serum iron levels are subject to physiological fluctuation and a deficiency can be caused by inflammation or neoplastic diseases.


Assuntos
Anemia/veterinária , Doenças dos Bovinos/diagnóstico , Ferritinas/sangue , Deficiências de Ferro , Medicina Veterinária/métodos , Anemia/induzido quimicamente , Anemia/diagnóstico , Animais , Bovinos , Doenças dos Bovinos/induzido quimicamente , Feminino , Ferro/sangue
17.
Am J Vet Res ; 69(10): 1247-53, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18828678

RESUMO

OBJECTIVE: To compare the content of substance P, vasoactive intestinal polypeptide, and neurofilament 200 in biopsy specimens taken from the abomasal wall of healthy cows of 2 breeds. SAMPLE POPULATION: Biopsy specimens taken from different sites of the abomasal wall from 20 German Holstein cows and 20 German Fleckvieh cows. PROCEDURES: Biopsy specimens were examined immunohistochemically, and the content of substance P, vasoactive intestinal polypeptide, and neurofilament 200 was determined by measuring the immunoreactive areas. RESULTS: Significant differences between the breeds were detected. Substance P-immuno-reactive area in the corpus abomasi was significantly smaller in the German Holsteins (geometric mean +/- geometric SD, 679 +/- 1.83 microm2) than in the German Fleckvieh cows (1,020 +/- 1.65 microm2). Concerning vasoactive intestinal polypeptide, differences between breeds were not significant. Overall nerve density in the antral abomasal wall was significantly greater in German Holsteins than in German Fleckvieh cows (immunoreactive areas for neurofilament 200 in German Holsteins was 4,842 +/- 1.29 microm2 and in German Fleckvieh cows was 3,333 +/- 1.63 microm2). Conclusions and Clinical Relevance-The significantly lower content of substance P in the corpus abomasi could explain why German Holstein cows are predisposed to abomasal displacement, compared with German Fleckvieh cows, in which this disease is a rare finding.


Assuntos
Parede Abdominal/fisiologia , Abomaso/química , Proteínas de Neurofilamentos/análise , Antro Pilórico/química , Substância P/análise , Peptídeo Intestinal Vasoativo/análise , Matadouros , Animais , Biópsia , Bovinos , Feminino , Alemanha , Especificidade da Espécie
18.
Am J Vet Res ; 67(3): 472-8, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16506910

RESUMO

OBJECTIVE: To compare results obtained by use of laparoscopyassisted abomasopexy versus omentopexy via right flank laparotomy for the treatment of dairy cows with left displaced abomasum (LDA). ANIMALS: 120 dairy cows with an LDA. PROCEDURE: In a prospective clinical trial, cows were randomly allocated to the abomasopexy group (laparoscopy-assisted abomasopexy) or to the control group (omentopexy via right flank). Data were obtained during the first 5 days after surgery and 6 weeks and 6 months after surgery. RESULTS: 59 of 60 cows in the abomasopexy group and all 60 cows in the control group were treated successfully. Median duration was shorter for the laparoscopic procedure (27.5 minutes), compared with that for the control group (38 minutes). Five cows in the abomasopexy group had wound complications and 2 had LDA relapses, compared with 2 wound complications and no relapses in the control group. During the 5 days after surgery, the abomasopexy group had a significantly higher increase in rate of energy intake and milk yield and a more rapid return to reference range for serum glutamic dehydrogenase activity and total bilirubin concentration, compared with results for the control group. CONCLUSIONS AND CLINICAL RELEVANCE: Success rates were almost equal for both methods. Advantages of the laparoscopic abomasopexy procedure include practicality, low risk of complications, and rapid postoperative recovery. Contraindications are cardiopulmonary diseases. Other disadvantages include the cost of the instruments and inability to perform the procedure in cows with abomasal adhesions.


Assuntos
Abomaso/cirurgia , Doenças dos Bovinos/cirurgia , Gastroenteropatias/veterinária , Laparoscopia/veterinária , Animais , Bovinos , Feminino , Gastroenteropatias/cirurgia , Laparoscopia/métodos
20.
Am J Vet Res ; 65(10): 1319-24, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15524316

RESUMO

OBJECTIVE: To determine the correlation between insulin concentrations and myoelectrical activity of the abomasum in cows with a left displaced abomasum (LDA). ANIMALS: 14 dairy cows with an LDA at the onset of lactation. PROCEDURE: During surgical correction of an LDA, 3 pairs of electrodes were placed in the smooth muscle of the gastrointestinal tract (abomasal body, pars pylorica, and duodenum) of each cow. Electromyographic recordings were obtained once per day for 7 days. Samples were collected and tested to determine concentrations of insulin, glucagon, cortisol, glucose, beta-hydroxybutyrate, and nonesterified fatty acids. RESULTS: All 14 cattle had high glucose and insulin concentrations at the time of admission, independent of ketosis. Concentrations of glucose and insulin decreased slowly after surgical treatment and were associated with a progressive increase in abomasoduodenal myoelectric activity. The 14 cows were allocated into 2 groups (suspected insulin-resistant cattle, n = 7; suspected non-insulin-resistant cattle, 7) on the basis of persistent hyperinsulinemia during the postoperative period. Seven days after surgery, the abomasoduodenal myoelectric patterns were still significantly lower for the insulin-resistant cows, compared with patterns for the non-insulin-resistant cows. CONCLUSIONS AND CLINICAL RELEVANCE: Insulin resistance appears to be common in cows with an LDA. Analysis of results of this study reveals that abomasal atony in cows with an LDA depends on persistence of high serum concentrations of insulin. Results of this study could provide an explanation for a pathogenetic factor of LDAs and the frequent relapses of cattle affected by this condition.


Assuntos
Abomaso/fisiopatologia , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/fisiopatologia , Motilidade Gastrointestinal/fisiologia , Resistência à Insulina , Gastropatias/veterinária , Ácido 3-Hidroxibutírico/sangue , Abomaso/cirurgia , Animais , Glicemia , Bovinos , Doenças dos Bovinos/cirurgia , Eletromiografia/veterinária , Ácidos Graxos não Esterificados/sangue , Feminino , Glucagon/sangue , Hidrocortisona/sangue , Insulina/sangue , Gastropatias/diagnóstico , Gastropatias/fisiopatologia , Gastropatias/cirurgia
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