Juan Manuel Ramírez Orduña - Academia.edu (original) (raw)

Papers by Juan Manuel Ramírez Orduña

Veterinary Parasitology, 2007

Larval midgut proteins of hematophagous parasites contain strong antigens that can be used for ho... more Larval midgut proteins of hematophagous parasites contain strong antigens that can be used for host immunization. This concept has been applied for immunization of Pelibuey sheep against Oestrus ovis L. (Diptera: Oestridae). The aim of this study was to examine the effect of immunization on larval establishment (LE) and development. Immunized lambs (I, n = 6) received two injections of crude gut membrane protein extracts (GMPE) from third instar larvae with Freund's incomplete adjuvant (FIA) on days 0 (Day of first immunization) and 21 (0.4 and 0.45 mg GMPE/lamb, respectively). The control group (C, n = 5) received physiological saline with FIA. Lambs were challenged with first instars on Day 29 (20 larvae) and Day 43 (25 larvae). Blood samples were collected biweekly and IgG titers were analyzed by ELISA. All lambs were slaughtered on Day 90 and number of larvae recovered, larval stage and larval weight were recorded at necropsy. No significant effect of immunization on LE (C = 28.9%; I = 31.0% P > 0.05) was observed. Antibody titers were higher in the immunized group on Day 28 (P < 0.05), but subsequently similar in both groups. Larval physiological age and weight were also significantly (P < 0.05) affected by immunization. Immunization of Pelibuey lambs with GMPE did not affect LE but did delay O. ovis larval development.

Hormones and Behavior, 2004

When female rats pace their coital interaction, a reward state evaluated by conditioned place pre... more When female rats pace their coital interaction, a reward state evaluated by conditioned place preference (CPP) is induced. Progesterone (P) is essential for the expression of proceptive behavior and for the induction of CPP. However, the functional significance of ring A reduction of P for the induction of this state during estrous is unsettled. In the present study, we evaluated whether ring A-reduced metabolites of P are involved in the reward state induced when the females are allowed to pace their sexual contacts. Ovariectomized (ovx) female rats treated with estradiol benzoate (EB, 5 Ag) and P (13 Ag), Megestrol acetate (MA; 13 Ag), 5a-pregnan-20 dione (5aDHP; 3 Ag), or 5hpregnan-3a-ol-20-one (5h,3a-Pgl; 3 Ag) were used. Progestins were dissolved in propylene glycol and intravenously (iv) injected through an indwelling jugular catheter before females were tested for pacing behavior. After 15 intromissions or one ejaculation, females were gently placed in the nonpreferred compartment of a CPP box. Paced mating in all groups treated with progestins induced a clear change of preference. The administration of progestins alone did not induce CPP. These results suggest that P and ring A-reduced metabolites facilitate the reward state following pacing.

The aim of this study was to characterize the natural infection by Eimeria spp . in goat kids, an... more The aim of this study was to characterize the natural infection by Eimeria spp . in goat kids, and to describe some pathophysiological responses to eimerosis in kids under intensive rearing conditions in B.C.S, Mexico. Nineteen adult crossbred does naturally infected with mixed Eimeria spp . and 20 Anglo Nubian x Creole crossbred kids were used. Oocyst per gram of feces (OPG) and identification of Eimeria species were determined in does (during the pre-kidding and post-kidding periods) and kids. Clinical signs, hematocrit, hemoglobin and alkaline phosphatase activity in blood serum were evaluated. OPG (meanÂ±SD) was significantly higher (P<0.05) in pre-kidding (9,478Â±7,599) than in post-kidding (5,313Â±2,909) period. Oocyst elimination in feces began at age 59Â±9 days in kids. Eimerian species identified were E. arloingi , E. jolchijevi , E. ninakohlyakimovae , E. hirci , E. christenseni and E. alijevi . Kids were humanely sacrificed to evaluate pathological lesions. Intestinal ...

The extent of vegetation used by free browsing goats on a rangeland is a practical measure to det... more The extent of vegetation used by free browsing goats on a rangeland is a practical measure to determine rangeland productivity and may be measured by the similarity indices between the botanical composition of diet and the rangeland. The aims of this study were to evaluate and compare, seasonally the similarity indices of forage species and goats diets under the Sonorant desert conditions. Samplings were carried out in summer and autumn of 2006, and winter 2007 in a 200-ha rangeland with an animal density of 0.13 to 0.36 individuals/ha. Twenty two fixed transects (30 m long) distributed randomly were used to measure the botanical composition and importance value (IV) for plant types by the line-intercept method. Identified species were classified as non legumes trees and shrubs (NLTS), legumes trees and shrubs (LTS), cacti, forbs, agaves and grasses. Five castrated Creole-Nubio goats (29 kg of BW) provided with esophageal fistula were used to obtain diet samples and determine botani...

How to cite Complete issue More information about this article Journal's homepage in redalyc.org ... more How to cite Complete issue More information about this article Journal's homepage in redalyc.org Scientific Information System Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Non-profit academic project, developed under the open access initiative

Veterinary Parasitology, 2009

Veterinary Parasitology, 2014

Two studies were carried out in order to test the effects of neem tree extracts (Azadirachta indi... more Two studies were carried out in order to test the effects of neem tree extracts (Azadirachta indica A. Juss) on sheep bot fly larvae (Oestrus ovis L. Diptera: Oestridae). First, aqueous extracts from neem seeds (ASNE) at 0, 5 y 10% (w/v) concentrations were tested on larval mortality in vitro. In a second study, the effect of oral administration with neem seed meal (0, 100 y 200 mg/kg) and neem leaves (1% of diet) on number of larvae found at necropsy and larval development was evaluated in experimentally O. ovis-infected sheep. Results in Experiment 1 showed a significant (P < 0.05) effect of ASNE on time to L1 mortality in a dosis-dependent manner. In Experiment 2, oral administration of seeds or leaves did not affect the number of larvae found at necropsy of the sheep, but interfered with larval development and there was a tendency to reduce larval weight at the end of the infection period (55 d).

Journal of Applied Animal Research, 2003

With the aiin to estimate seasoually the rote a.iLd extent of organic inutter degradability (EDOM... more With the aiin to estimate seasoually the rote a.iLd extent of organic inutter degradability (EDOM), ten irative species froin Baja Califoribia Sur, Mexico were evaluated. Branches froin the legumes: Acacia peninsularis (Brit. L. Rose) Standley; Cercidium floridium (Beitth); Mimosa xantii, Gray;

REDVET, 2009

... Carlos E.: Centro de Investigaciones Biológicas del Noroeste, La Paz, BCS, México | Cepeda-Pa... more ... Carlos E.: Centro de Investigaciones Biológicas del Noroeste, La Paz, BCS, México | Cepeda-Palacios, Ramón: Universidad Autónoma de Baja California Sur, La Paz, BCS México |Ascencio, Felipe: Centro ... Ana Valverde Onofre and Diana Tapiz Victoria for technical assistance ...

INTERCIENCIA- …, 2003

Ten native browse species from Baja California Sur, Mexico, were nutritionally evaluated in each ... more Ten native browse species from Baja California Sur, Mexico, were nutritionally evaluated in each season of three consecutive years measuring crude protein (CP), protein fraction in neutral detergent fiber (NDIP) and in acid detergent fiber (ADIP), and rate and extent of crude protein degradability. Five legumes and five non-legumes were collected from 16 linear 30m transects. All plants in each transect were identified and measured to estimate Shannon's diversity index, species richness, aerial cover and relative frequency, dominance, density and importance. Medicago sativa L. hay was used as reference forage with high nutritional quality. To estimate the effective degradability of crude protein (EDCP), duplicate nylon bags (10x15cm; 50µm pore size) containing 4g of each plant species from each season and year were incubated in the ventral part of the rumen in four cannulated beef steers. In general, CP content, NDIP, ADIP and EDCP were significantly higher in legumes. Neutral detergent soluble CP was higher in non-legumes during spring and summer, and CP and EDCP were higher in autumn. Legume EDCP was significantly lower in summer, possibly due to reduction of available cell wall protein. Only shrubs such as Opuntia cholla, Prosopis sp. and Cercidium floridium had EDCP values comparable to or higher than alfalfa hay. Cyrtocarpa edulis had the lowest EDCP. Legume CP was more degraded in the rumen than that of non-legumes. A high quality forage period in autumn and winter, and a low quality one in spring and summer, could be distinguished.

Hormones and Behavior, 1999

Progestins with a ␦-4-3-keto configuration bind to the progestin receptor (PR) and facilitate est... more Progestins with a ␦-4-3-keto configuration bind to the progestin receptor (PR) and facilitate estrous behavior in estrogen-primed rats. Some ring A-reduced progestins [5␣-dihydroprogesterone (␣DHP), allopregnanolone, and epipregnanolone] are more potent estrus-inducing agents than progesterone when iv injected despite their lower affinity for the PR. Yet the estrus-inducing action of such progestins is reduced by the antiprogestin RU486, suggesting that binding to the PR is required for this effect. Because allo-and epi-pregnanolone are oxidized to ␣and ␤DHP, respectively, by 3␣-hydroxysteroid oxo-reductase (3␣HSOR), part of their estrusinducing action may occur through the binding of such DHPs to the PR. Conversely, because 3␣HSOR reduces ␣and ␤DHP to allo-or epi-pregnanolone, both of which exert membrane effects, the estrus-inducing effect of DHPs may involve actions independent of the PR. To test these possibilities we assessed the effect of indomethacin, a blocker of 3␣HSOR, on the estrus-inducing action of such progestins. Because indomethacin also inhibits cyclooxygenases, we selected a dose and treatment schedule that does not interfere with prostaglandin-mediated brain processes (e.g., LHRH release). Indomethacin did not significantly modify the effect of progesterone or megestrol acetate on lordosis. Yet, it significantly reduced the action of all ring A-reduced progestins. Results suggest that: (a) oxidation is essential for lordosis facilitation by 3␣-pregnanolones and (b) reduction of 3-keto progestins generates 3␣hydroxy metabolites which synergize with processes triggered by occupation of the PR by 3-keto progestins. The possible participation in this response of other events influenced by indomethacin (e.g., prostaglandin or melatonin synthesis) is discussed.

Journal of Applied Animal Research

The effects of pregnancy and post-kidding stages, and the number of in utero developing foetuses ... more The effects of pregnancy and post-kidding stages, and the number of in utero developing foetuses on haematochemical parameters were evaluated in stabled cross-bred goats. Blood serum samples were collected biweekly during the late-pregnancy (-49 days) and post-kidding stages (21 days) (n = 34 goats, including 17 Anglonubian and 17 Saanen × Anglonubian). Non-pregnant, cross-bred, adult does (n = 17) were used as controls. Blood serum glucose (GL), total protein (TP), albumin (AL), uric acid (UA), total cholesterol (TC), total bilirubin (TB), creatinine (CR), and alkaline phosphatase (AP) were measured using commercial kits. Average GL, TP, AL, and AP values were found to be different (p < .05) in pregnant, control, and post-kidding stages. Average GL level was found to be different (p < .05) in Anglonubian vs. Saanen×Anglonubian goats. Number of developing foetuses had no effect on any measured haematochemical parameters. In conclusion, both the late pregnancy and post-kidding stages of Anglonubian and Saanen × Anglonubian goats were accompanied by changes in blood serum GL, TP, AL, and AP. Breed effect was only observed on serum GL, while number of kids developing in utero did not affect the measured haematochemical parameters of goats.

Southwestern Entomologist

SummaryThis is the abstract, Oestrus ovis (Diptera: Oestridae) is a nasosinusalparasite of sheep ... more SummaryThis is the abstract, Oestrus ovis (Diptera: Oestridae) is a nasosinusalparasite of sheep and goats that affects the wellbeing andperformance of the hosts. Our objectives were (1) to analyzeassociations of host phenotypic characteristics (age, weight, sex), O.ovis larval characteristics, systemic antibody IgG response, andlesions in sinusal and horn cavities in naturally infected goats, and (2)to estimate the serodiagnostic value of salivary gland antigens foroestrosis diagnosis by ELISA test in goats naturally exposed to O.ovis infection. O. ovis third-instar larvae (L3) were collected, thendissected to remove the salivary gland and to obtain the antigenssource (SGC). A total of 251 goats were necropsied. The host’sweight, age and sex were individually recorded. The sinusal and horncavities were examined for the presence of O. ovis larvae. Cavitarylesions and lesion intensity in infected goats (n=38) were scoredaccording to a severity table. Sera (n=125) were analyzed by ELI...

Pharmacology Biochemistry and Behavior, 2007

Dose-response curves for lordosis and proceptive behaviors were obtained for luteinizing hormone ... more Dose-response curves for lordosis and proceptive behaviors were obtained for luteinizing hormone releasing hormone (LHRH), prostaglandin E2 (PGE2) and dibutyryl cyclic AMP (db-cAMP), by infusing them in the right lateral ventricle (i.c.v.) of ovariectomized (OVX) estradiol benzoate (E2B; 2 microg) treated rats. Two dose levels, one producing the maximal effect and the other one producing a submaximal response (approximately ED50) were selected for testing the capacity of Rp-cAMPS, a kinase A blocker, to modify the behavioral response to the three compounds. I.c.v. injections of Rp-cAMPS, significantly depressed both lordosis and proceptive responses induced by LHRH, PGE2 and db-cAMP. The results show that these agents use the cAMP-kinase A signaling pathway to elicit their stimulating effect on estrous behavior in the rat.

Hormones and Behavior, 2006

Dose response curves for lordosis behavior was obtained for progesterone (P) and its two ring A-r... more Dose response curves for lordosis behavior was obtained for progesterone (P) and its two ring A-reduced metabolites: 5α-pregnanedione (α-DHP) and 5α,3α-pregnanolone (5α,3α-Pgl) by infusing these progestins in the right lateral ventricle (rlv) of ovariectomized (ovx) estradiol-treated rats (2 μg estradiol benzoate; EB), 40 h before intracerebro-ventricular (icv) injection. Effective doses 50 (ED50) revealed that ring A-reduced progestins were more potent than P itself to induce lordosis behavior. Two dose levels, one producing the maximal effect and the other one producing a submaximal response (ED50-ED60), were selected for testing the capacity of RpAMPS, a kinase A blocker, and H7, a kinase C blocker, to modify the response to the three progestins. rlv injection of RpAMPS significantly depressed the lordosis response to the two dose levels of P and α-DHP but failed to significantly inhibit that of 5α,3α-Pgl. The administration of H7 prevented the effect of both 5α-reduced progestins without affecting the response to P. The results suggest that P and its ring A-reduced metabolites stimulate lordosis behavior through different cellular mechanisms: P acting mainly through the cAMP-kinase system; α-DHP through both kinase A and kinase C signaling pathways and 5α,3α-Pgl through the kinase C system.