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2.
Behav Anal Pract ; 17(2): 514-522, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38966277

RESUMO

Behavior analysts can be found in a variety of settings including homes, schools, hospitals, workplaces, residential group homes, nursing homes, and universities (Association for Professional Behavior Analysts [APBA], 2019). As the field expands, behavior analysts find themselves performing a variety of tasks outside of traditional service delivery. A role of significant importance is that of the consultant. This article examines the status of training for behavior analysts. Our work finds that relatively few (11% of board certified behavior analyst programs and 3% of board certified associate behavior analyst programs) verified course sequences (VCSs) in behavior analysis include courses devoted specifically to consultation. Compared to other allied professions, there appears to be a disconnect between training and practice, especially when considering that behavior analysts are increasingly engaged in indirect service delivery through consultees. Finally, we discuss the benefits of consultation and why further devotion to and consistent requirements for training in consultation are needed. Several models of consultation appropriate for training behavior analysts are suggested, as well as information regarding how we might examine the effectiveness of consultation training.

4.
J Caffeine Res ; 5(4): 176-186, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26649253

RESUMO

Introduction: We present a review of the methodological aspects of caffeine research within animal tests of escape and avoidance behavior in the presence of aversive stimuli. Method: We highlight species, methods of caffeine administration, dosage, dependent measures, and research designs commonly used in this research. Results: Typical subjects were rodents and zebrafish, with species-specific vehicles of caffeine administration and dependent measures. Behavioral tests for escape and avoidance as a function of caffeine consumption were conceptually similar across species, although the arrangement of measures was necessarily adapted to the physiological contingencies of the different species. Discussion and Conclusions: Caffeine administration preceding the presentation of aversive stimuli generally, but not exclusively, enhanced the effect of escape and avoidance of aversive stimuli. The many commonalities in methods and results across species suggest similar methods may be relevant to human subjects as well.

5.
Brain Res Mol Brain Res ; 9(1-2): 79-86, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1850080

RESUMO

The effects of systemic kainic acid (KA) administration on hippocampal levels of prodynorphin and proenkephalin mRNA, as well as opioid peptides derived from these precursors, were evaluated. A single subcutaneous injection of KA induced a range of seizure states, from mild wet dog shakes to generalized motor seizures. Northern blot analysis of hippocampal mRNA revealed an increase in both prodynorphin and proenkephalin mRNA levels which corresponded to the intensity of the convulsions. Conversely, hippocampal levels of immunoreactive dynorphin A (1-8) and [Met]5-enkephalin were decreased as a function of seizure frequency and intensity. The time course of KA-induced alterations in prodynorphin and proenkephalin mRNA and peptide levels was also investigated. Hippocampal prodynorphin mRNA levels rose at a dramatic rate. At 3 h following KA administration, mRNA levels were maximally elevated approximately 13-fold. The levels decreased over a 48 h period, eventually reaching control values. In contrast, proenkephalin mRNA levels increased more slowly. At 24 h, a maximal 24-fold increase was observed. At 72 h after injection, proenkephalin mRNA levels were still slightly elevated. In the same experiment, immunoreactive enkephalin peptide levels, although somewhat decreased at 3-12 h, began to increase between 12 and 24 h after injection, and were still rising at 72 h. In marked contrast, immunoreactive dynorphin peptide levels ranged from 40% to 80% of control values at all times tested.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Encefalinas/biossíntese , Hipocampo/efeitos dos fármacos , Ácido Caínico/farmacologia , Precursores de Proteínas/biossíntese , RNA Mensageiro/biossíntese , Isomerases de Aminoácido/biossíntese , Isomerases de Aminoácido/genética , Animais , Proteínas de Transporte/biossíntese , Proteínas de Transporte/genética , Endorfinas/biossíntese , Endorfinas/metabolismo , Encefalinas/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/metabolismo , Injeções Subcutâneas , Ácido Caínico/administração & dosagem , Ácido Caínico/toxicidade , Masculino , Peptidilprolil Isomerase , Precursores de Proteínas/genética , Ratos , Ratos Endogâmicos F344 , Convulsões/induzido quimicamente , Convulsões/metabolismo
6.
J Neurosci Methods ; 23(2): 161-72, 1988 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3357356

RESUMO

Five unique, high affinity rabbit polyclonal antibodies against neuromedin B were characterized in a radioimmunoassay in terms of the following parameters: pH and type of buffer, ionic strength, and non-ionic detergents in order to optimize immunoglobulin-peptide interaction; specificity using peptides of the bombesin family, in addition to the tachykinin substance P; and affinity to neuromedin B. Optimum conditions included acidic pH (5.25), high ionic strength (greater than 0.1 M) and absence of non-ionic detergents, which inhibited the assay. Affinities for the 5 antibodies ranged from 10 to 48 fmol neuromedin B with titers from 1:1,000 to 1:10,000 and the sequence-specificity covered the entire peptide; cross-reactivity towards substance P was negligible. As a model tissue, rat spinal cord was homogenized with 5 different extraction solvents, including acetone, methanol, acid and alkaline conditions, and assayed by each polyclonal antiserum; neuromedin B immunoreactivity levels were highest in acid and alkaline extracts and reflected the specificity of the antibody used. Applying these antisera to rat brain extracts, the posterior pituitary gland contained the highest concentration of immunoreactive equivalents of neuromedin B followed by the anterior pituitary, hypothalamus, and hippocampus. The immunoreactive content in the pituitary and hypothalamus, however, depended on the particular antisera used with significant (P less than 0.01) differences existing between them. Further application of these polyclonal antibodies to a spinal cord extract analyzed by isocratic reverse-phase HPLC conditions also revealed differences in their cross-reactivity with the immunoreactive peptides. These antisera may now be used as molecular probes for the determination of extractable immunoreactive neuromedin B from neural tissue and in situ localization by immunohistochemical techniques.


Assuntos
Química Encefálica , Neurocinina B/análogos & derivados , Neuropeptídeos/análise , Medula Espinal/análise , Sequência de Aminoácidos , Animais , Anticorpos , Cromatografia Líquida de Alta Pressão/métodos , Reações Cruzadas , Dados de Sequência Molecular , Neuropeptídeos/imunologia , Radioimunoensaio/métodos , Relação Estrutura-Atividade
7.
Brain Res ; 477(1-2): 100-8, 1989 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-2539228

RESUMO

Quantitative in vitro autoradiography was used to assess the effects of kainic acid (KA) and colchicine (COL) on mu and lambda opiate binding in the rat hippocampus. Rats were treated with either systemic KA, a neurotoxin that damages CA3 pyramidal cells and causes seizures and wet-dog shakes, or intrahippocampal COL to destroy dentate granule cells and their mossy fibers, or both toxins. Moderate levels of mu binding were detected in the pyramidal layer and in the stratum lacunosum-moleculare; binding was greater in the ventral hippocampus. Levels of mu binding were markedly increased in all regions 48 h after treatment with KA. Two weeks after COL treatment, there was a modest decrease in mu binding; COL plus KA gave results similar to COL alone. Dense lambda binding was present over the mossy fibers in the stratum lucidum, but was absent over the pyramidal layer. In contrast to mu binding, lambda binding was greater in the dorsal hippocampus. KA alone had little effect on lambda binding, whereas COL alone caused large decreases. KA plus COL caused even larger decreases in lambda binding, to as much as 85% below control. These results demonstrate that mu and lambda binding are localized to different parts of the hippocampus, respond differently to neurotoxin lesions, and likely serve different roles in this brain region. The number of mu sites is responsive to the release of enkephalin; these receptors appear to be linked to opiate-induced hippocampal seizure activity, especially wet-dog shakes. Lambda sites may serve as autoreceptors on mossy fibers.


Assuntos
Colchicina/farmacologia , Hipocampo/metabolismo , Ácido Caínico/farmacologia , Receptores Opioides/metabolismo , Receptores Virais/metabolismo , Animais , Autorradiografia , Proteínas da Membrana Bacteriana Externa , Di-Hidromorfina/metabolismo , Hipocampo/efeitos dos fármacos , Masculino , Naloxona/metabolismo , Porinas , Ratos , Ratos Endogâmicos F344 , Receptores Opioides/efeitos dos fármacos , Receptores Opioides mu , Receptores Virais/efeitos dos fármacos , Valores de Referência , Trítio
8.
Brain Res ; 480(1-2): 322-5, 1989 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-2713658

RESUMO

Glucocorticoid effects on kainic acid-induced motor seizures and wet dog shakes in rats were investigated by adrenalectomy and dexamethasone treatment. One-day adrenalectomy attenuated kainic acid-induced wet dog shakes and seizure activity. These effects were restored by dexamethasone. Administration of dexamethasone to non-adrenalectomized rats potentiated kainic acid-induced wet dog shakes and severity of seizure activity. These results suggest that glucocorticoids may play an important role in modulating the severity of kainic acid-induced seizures and wet dog shakes.


Assuntos
Dexametasona/farmacologia , Glucocorticoides/fisiologia , Ácido Caínico , Convulsões/induzido quimicamente , Adrenalectomia , Animais , Relação Dose-Resposta a Droga , Interações Medicamentosas , Glucocorticoides/farmacologia , Masculino , Ratos , Ratos Endogâmicos F344 , Convulsões/fisiopatologia
9.
Brain Res ; 506(2): 327-30, 1990 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-2154290

RESUMO

Male Fischer-344 rats were injected i.p. with diethyldithiocarbamate or dithizone 15 min after kainic acid (KA), s.c. Diethyldithiocarbamate and dithizone reduced both the number of wet dog shakes and the latency to onset of seizures induced by KA. Moreover, they increased the severity of seizures. These compounds may be useful tools for investigating the role of zinc in central nervous system excitatory transmission and/or convulsive phenomena.


Assuntos
Compostos Azo/farmacologia , Quelantes/farmacologia , Ditizona/farmacologia , Ácido Caínico/toxicidade , Convulsões/induzido quimicamente , Zinco/metabolismo , Animais , Ditiocarb/farmacologia , Masculino , Ratos , Ratos Endogâmicos F344 , Tempo de Reação/efeitos dos fármacos , Convulsões/metabolismo , Convulsões/fisiopatologia
10.
Brain Res ; 511(2): 338-40, 1990 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-2334852

RESUMO

Wet dog shaking elicited by systemic administration of kainic acid is eliminated by bilateral destruction of ventral dentate granule cells. In contrast, wet dog shaking induced by naltrexone precipitated abstinence in morphine-dependent rats is unaffected by destruction of ventral dentate granule cells. It is concluded that at least two anatomically distinct brain regions modulate wet dog shaking behavior.


Assuntos
Hipocampo/fisiologia , Ácido Caínico/toxicidade , Morfina , Comportamento Estereotipado/efeitos dos fármacos , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Animais , Hipocampo/efeitos dos fármacos , Masculino , Naloxona/farmacologia , Ratos , Ratos Endogâmicos F344
11.
Brain Res ; 435(1-2): 343-7, 1987 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-2892578

RESUMO

This investigation demonstrates that stimulation of the perforant path under conditions which elicit wet dog shakes in rats produces a significant decrease in hippocampal levels of methionine-enkephalin, dynorphin A(1-8) and glutamine, and an increase in gamma-aminobutyric acid (GABA). Levels of these substances are not altered by stimulus parameters insufficient to elicit wet dog shakes. These results lend support to the notion that endogenous opioid peptides play a role in regulation of hippocampal excitability but may only be released under relatively intense stimulus conditions. The increase in GABA levels could be due to an increase in synthesis, an increase in reuptake or a reduction in release. The latter possibility is consistent with reports that iontophoretically applied enkephalin exerts its apparent excitatory effects via an inhibitory action on inhibitory neurons in the hippocampus.


Assuntos
Dinorfinas/metabolismo , Encefalina Metionina/metabolismo , Glutamina/metabolismo , Hipocampo/fisiologia , Fragmentos de Peptídeos/metabolismo , Comportamento Estereotipado , Ácido gama-Aminobutírico/metabolismo , Aminoácidos/metabolismo , Animais , Estimulação Elétrica , Hipocampo/metabolismo , Masculino , Ratos , Ratos Endogâmicos F344
12.
Brain Res ; 514(1): 167-70, 1990 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-2357524

RESUMO

Intrahippocampal injections of colchicine selectively destroy dentate granule cells. Wet dog shaking elicited by systemic administration of kainic acid is eliminated by bilateral destruction of ventral dentate granule cells but unaffected by bilateral destruction of dorsal dentate granule cells. This implies that ventral dentate granule cells are essential for the generation of kainic acid-induced wet dog shakes.


Assuntos
Hipocampo/fisiologia , Ácido Caínico/farmacologia , Convulsões/induzido quimicamente , Comportamento Estereotipado/fisiologia , Animais , Hipocampo/efeitos dos fármacos , Hipocampo/fisiopatologia , Masculino , Ratos , Ratos Endogâmicos F344 , Convulsões/fisiopatologia , Comportamento Estereotipado/efeitos dos fármacos
13.
Brain Res ; 408(1-2): 163-72, 1987 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-2885066

RESUMO

Rats were given bilateral injections of colchicine into the dorsal and ventral hippocampus. Behavioral, neurochemical and histopathological measurements were taken, up to 12 weeks after surgery. Colchicine produced a consistent increase in spontaneous motor activity, enhanced acoustic startle reactivity, and accelerated acquisition of two-way shuttle box avoidance, but did not affect reactivity to a noxious thermal stimulus. Measurement of dynorphin in the hippocampus indicated that colchicine rapidly depleted this neuropeptide, which is thought to be contained preferentially in the mossy fibers of granule cells of the hippocampus. Colchicine also decreased Met-enkephalin in the hippocampus, but the magnitude of the change (22%) was less than that (89% depletion) observed for hippocampal dynorphin. Examination of hippocampal morphology using light microscopic techniques indicated that colchicine caused approximately 60% degeneration of granule cells in the hippocampus. Although the length of the pyramidal cells was decreased (12-16%), the width of the CA1 and CA3 region of the hippocampus was not affected. These data underscore the importance of the granule cells in the mediation of behavioral processes such as motor activity, startle reactivity and performance of shuttle box avoidance.


Assuntos
Comportamento Animal/efeitos dos fármacos , Colchicina/farmacologia , Hipocampo/efeitos dos fármacos , Estimulação Acústica , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Dinorfinas/metabolismo , Encefalina Metionina/metabolismo , Hipocampo/metabolismo , Hipocampo/patologia , Masculino , Atividade Motora/efeitos dos fármacos , Dor/fisiopatologia , Fragmentos de Peptídeos/metabolismo , Ratos , Ratos Endogâmicos F344 , Tempo de Reação/efeitos dos fármacos , Reflexo de Sobressalto/efeitos dos fármacos , Fatores de Tempo
14.
Brain Res ; 577(2): 312-7, 1992 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-1376635

RESUMO

The rat striatum after dopamine denervation followed by repeated apomorphine treatment was examined for the co-expression of c-fos and Fos-related antigens with dynorphin, substance P and [Met5]enkephalin using Western blot and immunohistochemical techniques. Administration of apomorphine, a dopamine agonist, elevated the level of 35 kDa Fos-related antigen which co-localized with dynorphin and substance P, but not enkephalin, in striatal neurons.


Assuntos
Corpo Estriado/imunologia , Dinorfinas/análise , Neurônios/imunologia , Proteínas Proto-Oncogênicas c-fos/análise , Substância P/análise , Substância Negra/fisiologia , Animais , Apomorfina/farmacologia , Western Blotting , Corpo Estriado/química , Corpo Estriado/citologia , Corpo Estriado/efeitos dos fármacos , Dopamina/fisiologia , Genes fos/efeitos dos fármacos , Imuno-Histoquímica , Masculino , Peso Molecular , Neurônios/química , Ratos , Ratos Endogâmicos , Substância Negra/efeitos dos fármacos
15.
Toxicology ; 46(2): 141-57, 1987 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-2890224

RESUMO

Kainic acid (KA), an excitatory neurotoxin, was used as a tool to study the metabolism of hippocampal opioid peptides and their functional role in the expression of wet-dog shakes (WDS). A single intracerebral injection of KA (1 microgram/rat) caused recurrent motor seizures lasting 3-6 h. During the convulsive period, native Met5-enkephalin-like (ME-LI) and dynorphin A(1-8)-like (DYN-LI) immunoreactivities in hippocampus decreased by 31 and 63%, respectively. By 24 h after dosing, the hippocampal opioid peptides had returned to control levels, and by 48 h ME-LI had increased 270% and DYN-LI 150%. Immunocytochemical analysis revealed that ME-LI and Leu5-enkephalin-like (LE-LI) immunostaining in the mossy fibers of dentate granule cells and the perforant-temporoammonic pathway had decreased visibly by 6 h and had increased markedly by 48 h following KA. A visible decrease in DYN-LI in mossy fiber axons within 6 h was followed by a substantial increase at 48 h. To determine whether the increases in hippocampal ME-LI reflected changes in ME biosynthesis, levels of mRNA coding for preproenkephalin (mRNAenk) and cryptic ME-LI cleaved by enzyme digestion from preproenkephalin were measured. Following the convulsive period (6 h), mRNAenk was 400% of control, and by 24 h, cryptic ME-LI was 300% of control. Increases in native and cryptic ME-LI and in mRNAenk were also noted in entorhinal cortex, but not in hypothalamus or uninjected striatum. Our data suggest that KA-induced seizures cause an increase in ME release, followed by a compensatory increase in ME biosynthesis in the hippocampus and entorhinal cortex. Several lines of evidence from this study have suggested that hippocampal enkephalins are intimately related to KA-elicited WDS. The shaking behavior was attenuated by pretreatment with naloxone or antisera against [Met5]-enkephalin. We also observed that KA-induced WDS can be mimicked by intrahippocampal injection of enkephalin-related peptides. Furthermore, this study demonstrated that intact dentate granule cells are essential for KA- and enkephalin-induced WDS, since a colchicine injection into the ventral hippocampus, which selectively destroys granule cells, abolished this behavior.


Assuntos
Endorfinas/metabolismo , Hipocampo/efeitos dos fármacos , Ácido Caínico/toxicidade , Animais , Dinorfinas/metabolismo , Encefalina Metionina/análogos & derivados , Encefalina Metionina/metabolismo , Hipocampo/metabolismo , Fragmentos de Peptídeos/metabolismo , Ratos , Convulsões/induzido quimicamente
16.
J Morphol ; 146(4): 533-42, 1975 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1171254

RESUMO

Rabbits are unique among mammals in that their ears can regenerate tissues from the margins of full thickness holes which grow in and completely fill the opening in about two months. The circular blastema that forms around the edges of the hole differentiates a new sheet of cartilage as it regenerates in a centripetal direction. Similar holes in other mammals fail to regenerate and form scar tissue instead of a blastema. Histological studies of the healing around the edges of rabbit ear holes reveal that during the second week, when the epidermis is completing its migration across the wound from the opposite sides of the ear, conspicuous tongues of epidermal cells grow down into the underlying tissues at the edges of the wound. These epidermal downgrowths are situated between the original intact dermis of the skin and the more central tissues which give rise to the blastema. Such downgrowths are of a transient nature, and are no longer found once the blastema rounds up toward the end of the second week. Since they are not found in the healing of similar wounds in rabbit ears prevented from regenerating by prior removal of their cartilaginous sheets, nor in the naturally nonregenerating ears of sheep and dogs, it is considered that these downgrowths of healing epidermis may play a role in the unusual regenerative response of ear tissues in the rabbit.


Assuntos
Orelha Externa/crescimento & desenvolvimento , Coelhos/fisiologia , Regeneração , Cicatrização , Animais , Cartilagem/crescimento & desenvolvimento , Cartilagem/fisiologia , Queratinas/fisiologia
17.
J Investig Med ; 47(8): 369-77, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10510589

RESUMO

UNLABELLED: PHYSIOLOGICAL MECHANISM: A rapid change of length applied during isometric contraction of skeletal or cardiac muscle may result in redeveloped tension less than appropriate for the new length because of "deactivation" of the contractile system. The amount of shortening deactivation is directly related to both the time during the contraction when the length change occurs and to the extent of muscle shortening. If the muscle is permitted to shorten early in the contraction, the redeveloped tension will be appropriate to the new length as predicted from the classic Frank-Starling relationship. However, the same length change, which is imposed later in the contraction, results in a redeveloped tension that is less than predicted. Furthermore, a greater change in length results in less tension being redeveloped than if a smaller length decrement is applied at the same time during the contraction. It has been demonstrated that the reduced tension during active muscle shortening is associated with reduced affinity of troponin C for Ca2+. The free Ca2+ is then picked up by the SR, with less Ca2+ available for tension development until the subsequent contraction. CLINICAL SIGNIFICANCE: Although the clinical significance of shortening deactivation remains speculative, it seems likely that in the intact heart deactivation would affect myocardial O2 consumption. The decreased efficiency with which the heart maintains a given stroke work against a high afterload might be related to the lesser degree of fiber shortening and, therefore, less shortening deactivation. Conversely, it is well-known that the same level of stroke work accomplished by an increase in end-diastolic volume requires much less O2. This may be related, at least in part, to the greater degree of shortening with an accompanying increase in deactivation under the latter conditions. For example, in congestive heart failure where ejection fraction and fiber shortening are minimal, the maintenance of the longer fiber lengths could significantly increase the MVO2. Ford has suggested that the deactivating effect of shortening produced by afterload reduction would limit energy expenditure, therefore, exerting a favorable effect on the failing myocardium. It would also seem that an inotropic agent that increased shortening deactivation might compensate for the increased MVO2 caused by the inotrope and have a favorable effect on cardiac work. From most of the studies we have reviewed, it appears likely that shortening deactivation acts as a physiological "feedback" mechanism that affects afterload and in turn, myocardial oxygen consumption. Pathological situations such as acidosis and ischemia have been associated with reduced myofilament Ca2+ sensitivity or affinity and depressed cardiac contractility. Is it then possible that interventions that increase Ca2+ sensitivity might favorably alter ventricular pressure-volume relations during ejection and improve myocardial function by reducing the magnitude of shortening deactivation? Whatever the mechanism and clinical significance, future investigations will help to define the role of shortening deactivation in modifying ventricular function.


Assuntos
Cardiopatias/fisiopatologia , Coração/fisiologia , Contração Miocárdica/fisiologia , Animais , Cálcio/metabolismo , Cardiopatias/metabolismo , Humanos , Contração Isométrica , Consumo de Oxigênio , Músculos Papilares/fisiologia
18.
J Parasitol ; 62(3): 432-41, 1976 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-932917

RESUMO

One hundred and seventy-two specimens of Erimyzon oblongus from Lake Raleigh, North Carolina, were examined for caryophyllaeid cestodes from December 1972 to July 1974. Monobothrium ulmeri, Biacetabulum meridianum, and an undescribed species of Penarchigetes were recovered from the "stomach," "pyloric bend," and the first loop of the small intestine of the suckers. Infections of M. ulmeri were limited to an 8-month period and were seasonally periodic in prevalence, mean intensity, maturation, and length distribution. A "temperature dependeant rejection response" is discussed as a possible factor involved in the periodicity of this species. The maturation of M. ulmeri corresponded closely to the host's reproductive cycle, and may have been affected by changes in the host's hormonal levels during the spring. Infections of R. meridianum were present throughout the year, and exhibited a seasonal periodicity in prevalence, maturation, and length distribution. The mean intensity of infection suggests that the establishment of this species is inhibited by heavy burdens of M. ulmeri. Penarchigetes sp. was nonseasonal in prevalence, mean intensity, and maturation. The continuous availability of infective procercoids and the lack of a sucker "rejection response" are discussed as possible explanations for this destribution. Unlike B. meridianum and Penarchigetes sp., the mean intensity of M. ulmeri showed a close relationship with host sex.


Assuntos
Infecções por Cestoides/veterinária , Doenças dos Peixes/epidemiologia , Animais , Cestoides/crescimento & desenvolvimento , Infecções por Cestoides/epidemiologia , Infecções por Cestoides/parasitologia , Feminino , Doenças dos Peixes/parasitologia , Peixes , Intestino Delgado/parasitologia , Masculino , Estações do Ano , Estômago/parasitologia
19.
Theriogenology ; 49(8): 1515-23, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10732015

RESUMO

Records of 2191 calvings from the Clemson University Beef Physiology Unit between 1981 and 1993 were analyzed to determine factors affecting malpresentation, mortality and dystocia. Only 20 (0.91%) parturitions involved malpresentation: posterior presentation (n = 14), leg deviations (n = 3), head deviations (n = 2) and breech birth (n = 1). Dystocia affected calf mortality within 24 h of birth (P < 0.05), with mortality increasing as the severity of dystocia increased. There was an overall 4.5% death loss within 24 h of birth, with 4 and 7% mortality rates for calves from multiparous and primiparous dams, respectively (P < 0.05). Mortality was higher for bull vs heifer calves (P < 0.05). Ninety-four percent of calvings were unassisted, while 6% were assisted births. Dystocia was greater (P < 0.01) in primiparous (17%) than in multiparous dams (4%). In births involving dystocia, 28.1% required mild traction, 69.3% required heavy traction and 2.6% required Cesarean section. Birth weights associated with normal births and mild traction (36 and 36 kg) were lighter than those associated with heavy traction and Cesarean section (40 and 42 kg, respectively; P < 0.05). In conclusion, malpresentations were too few to be of significance, and dystocia influenced mortality within 24 h of birth. Calf birth weight and parity of dam explained most of the observed variations in dystocia.


Assuntos
Apresentação Pélvica , Doenças dos Bovinos/mortalidade , Distocia/veterinária , Fatores Etários , Animais , Peso ao Nascer , Bovinos , Cesárea/veterinária , Distocia/mortalidade , Feminino , Masculino , Paridade , Gravidez , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais
20.
Theriogenology ; 14(2): 135-49, 1980 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16725519

RESUMO

A study was performed to examine the release patterns of prolactin and LH of young beef cows with one (single calf) or two calves (double calf) throughout the postpartum interval. The effect on prolactin release of intramuscular and intra-carotid administration of lergotrile and intra-carotid administration of L-dopa was also examined. In approximately 50% and 65% of the cases, no prolactin release could be detected after the beginning of or during the suckling stimulus in cows with one or two calves respectively. LH plasma concentrations remained constant throughout the experiment in all animals. The chosen intramuscular lergotrile treatment lowered plasma prolactin concentrations to baseline levels but had no effect on the length of the postpartum interval. No effect on prolactin release was observed by the given intra-carotid treatments of both lergotrile and L-dopa. First postpartum estrus was observed on days 67 and 88 in the single and double calf cows respectively. The number of suckling periods did not change during the postpartum period but their duration decreased during the same period. These results demonstrate that in at least half of the cases the suckling stimulus does not cause a release of prolactin from the pituitary in the young beef cow. Also, the inhibitory effect of suckling on the resumption of ovarian cyclic function postpartum appears to be of a quantitative nature and mediated by a factor other than prolactin.

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