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1.
Univ. psychol ; 16(supl.5): 234-247, dic. 2017. tab, graf
Article in Spanish | LILACS, COLNAL | ID: biblio-979465

ABSTRACT

Resumen La integración social (IS) se presenta como un fenómeno clave en la complejidad de las sociedades actuales. Son escasas las investigaciones que consideran una perspectiva psicosocial para evaluar la IS. En el presente trabajo, se plantea una propuesta que tiene en cuenta tales dimensiones en población colombiana con desplazamiento forzado y cubana con migración económica, residentes en Quito (Ecuador). Participaron 255 personas a quienes se evalúan la anomia y arraigo social. Se encuentra que, en ambos grupos de participantes, la presencia o ausencia de trabajo condiciona la anomia o arraigo social. Estos resultados presentan implicaciones sobre diversas políticas de inmigración, en las cuales la integración social requeriría incorporar dimensiones psicosociales para abordar tal proceso.


Abstract Social Integration (SI) is presented as a key phenomenon in the complexity of today's societies. There are few investigations that considered psychosocial perspective to evaluate SI and here we propose a proposal that considers such dimensions in Colombian population with forced displacement and Cuban with economic migration residing in Quito, Ecuador. 255 persons participated who are evaluated anomia and social roots. The models of mediation show that in both groups of participants, the presence or absence of work conditions the social anomia or rootedness. These results have implications for various immigration policies, in which social integration requires incorporating psychosocial dimensions to address such a process. Keyword social integration; forced and economic migration in Ecuador; integration policies Introducción


Subject(s)
Humans , Social Welfare , Ecuador , Human Migration
2.
Spinal Cord Ser Cases ; 3: 17089, 2017.
Article in English | MEDLINE | ID: mdl-29423295

ABSTRACT

STUDY DESIGN: Pilot study. OBJECTIVES: Single-nucleotide polymorphisms (SNPs) in TRPA1 gene are related to the etiology of chronic pain. The study is a pilot study with the primary objective of analyzing these SNPs in Spanish patients with chronic and complete spinal cord injury (SCI) and neuropathic pain (NPP). SETTING: Asepeyo Hospital Department of Chronic and Complete SCI. METHODS: Twelve patients with chronic and complete SCI and NPP, and 12 patients with chronic and complete SCI with no pain were reviewed. International Spinal Cord Injury Pain Classification (LANSS) and visual analog score (VAS) were chosen to classify pain syndrome. SNPs were identified by melting analysis after DNA amplification with real-time fluorescence PCR. RESULTS: There were differences in rs11988795 variant: GG homozygous (p = 0.01) and G allele (p = 0.001) were more frequent in SCI patients with no pain. There were differences in rs13255063 variant: TT homozygous were prevalent (p = 0.03) in patients with NPP. CONCLUSIONS: Until now this is the first study to show a description of TRPA1 SNPs in Spanish patients with chronic and complete SCI and NPP. These results suggest that GG genotype in rs11988795 variant and G allele could be protective factors against NPP. TT genotype in rs13255063 variant could be a risk factor for NPP. Neuropathic pain after spinal cord injuries may have genetic contributions.

3.
J Geophys Res Space Phys ; 121(8): 7870-7880, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27774373

ABSTRACT

A miniature atomic scalar magnetometer based on the rubidium isotope 87Rb was developed for operation in space. The instrument design implements both Mx and Mz mode operation and leverages a novel microelectromechanical system (MEMS) fabricated vapor cell and a custom silicon-on-sapphire (SOS) complementary metal-oxide-semiconductor (CMOS) integrated circuit. The vapor cell has a volume of only 1 mm3 so that it can be efficiently heated to its operating temperature by a specially designed, low-magnetic-field-generating resistive heater implemented in multiple metal layers of the transparent sapphire substrate of the SOS-CMOS chips. The SOS-CMOS chip also hosts the Helmholtz coil and associated circuitry to stimulate the magnetically sensitive atomic resonance and temperature sensors. The prototype instrument has a total mass of fewer than 500 g and uses less than 1 W of power, while maintaining a sensitivity of 15 pT/√Hz at 1 Hz, comparable to present state-of-the-art absolute magnetometers.

4.
Physiol Meas ; 37(9): N62-75, 2016 09.
Article in English | MEDLINE | ID: mdl-27531394

ABSTRACT

Fatigue is a major contributing factor to operational errors. Therefore, the validation of objective and sensitive indices to detect fatigue is critical to prevent accidents and catastrophes. Whereas tests based on saccadic velocity (SV) have become popular, their sensitivity in the military is not yet clear, since most research has been conducted in laboratory settings using not fully validated instruments. Field studies remain scarce, especially in extreme conditions such as real flights. Here, we investigated the effects of real, long flights on SV. We assessed five newly commissioned military helicopter pilots during their aviation training. Pilots flew Sikorsky S-76C helicopters, under instrumental flight rules, for more than 2 h (ca. 150 min). Eye movements were recorded before and after the flight with an eye tracker using a standard guided-saccade task. We also collected subjective ratings of fatigue. SV significantly decreased from the Pre-Flight to the Post-Flight session in all pilots by around 3% (range: 1-4%). Subjective ratings showed the same tendency. We provide conclusive evidence about the high sensitivity of fatigue tests based on SV in real flight conditions, even in small samples. This result might offer military medical departments a valid and useful biomarker of warfighter physiological state.


Subject(s)
Fatigue/diagnosis , Fatigue/physiopathology , Military Personnel , Saccades , Adult , Humans , Male , Pilots
5.
IEEE Trans Biomed Circuits Syst ; 10(2): 269-79, 2016 Apr.
Article in English | MEDLINE | ID: mdl-25974945

ABSTRACT

We present a high-voltage CMOS neural-interface chip for a multichannel vestibular prosthesis (MVP) that measures head motion and modulates vestibular nerve activity to restore vision- and posture-stabilizing reflexes. This application specific integrated circuit neural interface (ASIC-NI) chip was designed to work with a commercially available microcontroller, which controls the ASIC-NI via a fast parallel interface to deliver biphasic stimulation pulses with 9-bit programmable current amplitude via 16 stimulation channels. The chip was fabricated in the ONSemi C5 0.5 micron, high-voltage CMOS process and can accommodate compliance voltages up to 12 V, stimulating vestibular nerve branches using biphasic current pulses up to 1.45±0.06 mA with durations as short as 10 µs/phase. The ASIC-NI includes a dedicated digital-to-analog converter for each channel, enabling it to perform complex multipolar stimulation. The ASIC-NI replaces discrete components that cover nearly half of the 2nd generation MVP (MVP2) printed circuit board, reducing the MVP system size by 48% and power consumption by 17%. Physiological tests of the ASIC-based MVP system (MVP2A) in a rhesus monkey produced reflexive eye movement responses to prosthetic stimulation similar to those observed when using the MVP2. Sinusoidal modulation of stimulus pulse rate from 68-130 pulses per second at frequencies from 0.1 to 5 Hz elicited appropriately-directed slow phase eye velocities ranging in amplitude from 1.9-16.7 °/s for the MVP2 and 2.0-14.2 °/s for the MVP2A. The eye velocities evoked by MVP2 and MVP2A showed no significant difference ( t-test, p=0.34), suggesting that the MVP2A achieves performance at least as good as the larger MVP2.


Subject(s)
Head Movements , Neural Prostheses , Vestibular Nerve/physiology , Animals , Electric Stimulation/instrumentation , Equipment Design , Humans , Vestibular Diseases/therapy
7.
FMC ; 15(8): 489-498, 2008 Oct.
Article in Spanish | MEDLINE | ID: mdl-32288494
8.
Aviat Space Environ Med ; 78(8): 784-8, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17760286

ABSTRACT

BACKGROUND: Disorders of the spine are common in fighter crewmembers. The high cost of training and experience for pilots makes it important to use all reasonable clinical means to restore grounded pilots to their flying duties, provided that all safety standards are maintained. To date, there has been limited research into specific surgical treatment of spine injury in pilots. This study was designed to examine the efficacy of surgical procedures in Spanish Air Force fighter pilots with injuries to the spine, as well as the aeromedical disposition of such pilots. METHODS: A retrospective study was conducted using the medical records of 14 fighter pilots with symptomatic spinal disorders treated by surgery. RESULTS: The 14 pilots underwent surgery: 12 cases involved fusion of vertebral structures (arthrodesis), while 2 pilots underwent discectomy. All pilots were subsequently given waivers to resume flying duties. DISCUSSION: The successful return to flight status of these pilots indicates the practical application of surgical techniques that safely stabilize the spine. However, due the sample limited size of the sample, further studies are needed.


Subject(s)
Arthrodesis , Diskectomy , Intervertebral Disc Displacement/surgery , Military Personnel , Occupational Diseases/surgery , Adult , Aerospace Medicine , Humans , Intervertebral Disc Displacement/rehabilitation , Occupational Diseases/rehabilitation , Retrospective Studies , Spain , Treatment Outcome
11.
Pediatr Dermatol ; 22(6): 513-9, 2005.
Article in English | MEDLINE | ID: mdl-16354252

ABSTRACT

Childhood exposure to ultraviolet radiation from the sun and a history of sunburns are risk factors for skin cancer. Because children spend time outdoors when they are at school, school sun protection policies are an important health issue, particularly in areas of the country with year-round warm and sunny climates, such as Florida. To better understand the sun protection policies and practices in South Florida schools, a sample (n = 51) of elementary and middle schools in Miami-Dade County public schools were surveyed as part of a CDC-funded cancer control program at the University of Miami. Of the principals and teachers surveyed, most (78%) knew about the county school system's guidelines for avoiding excessive heat exposure, which include two sun protection measures. Two-thirds reported that they shared these guidelines with teachers; 21% shared them with parents. Few schools monitor implementation of the guidelines, although 70% schedule outdoor activities to avoid peak sun hours. No schools required sunscreen, hats, or protective clothing. Physical education teachers and students spend an average of 4.5 and 0.6 hours per day outdoors, respectively. Improved school sun protection policies and monitoring of such policies is needed to reduce sun exposure and skin cancer risk for both students and staff.


Subject(s)
Health Promotion/organization & administration , School Health Services/organization & administration , Skin Neoplasms/prevention & control , Sunlight , Ultraviolet Rays , Adolescent , Child , Child, Preschool , Data Collection , Female , Florida , Health Education/organization & administration , Humans , Male , Multicenter Studies as Topic , Policy Making , Program Evaluation , Protective Clothing , Risk Assessment , Schools , Sunscreening Agents/administration & dosage , Surveys and Questionnaires
12.
Aviat Space Environ Med ; 76(6): 566-8, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15945401

ABSTRACT

BACKGROUND: Phobic fear of flying may affect aircrew members during any phase of their flying careers. Symptoms are beyond voluntary control and may lead patients to avoid flying and seek medical advice. METHODS: Of 1101 psychiatric files from our institute for 1985-2002, 150 represented cases of fliers who suffered from phobic fear of flying. Data collected from those files included assessment of fear-evoking situations, type of aircraft, class of aircrew duties, aircraft accident history, past medical history, age, and associated psychiatric comorbidity. RESULTS: We compared a group of 56 pilots with 94 other aircrew members. Results included 143 cases of flight phobia behavior and 7 cases of anxiety about parachuting. Flight phobia was less frequent among pilots (37.4%) than the other aircrew members (62.6%). We found a history of aircraft accident to the patient or an acquaintance in 25% of the cases. Observed comorbid psychiatric disorders (54%) consisted of depressive disorders (22%), anxiety disorders (16%), and personality disorders (7.4%). Fixed-wing pilots and aircrews members had a higher incidence of depression than did rotary-wing pilots and crewmembers (p < 0.05). Rotary-wing pilots and crewmembers had a higher rate of anxiety disorders (p < 0.05). DISCUSSION: Flight phobia encompasses a wide spectrum of clinical origins that may lead pilots or other aircrew members to refuse to fly. We recommend a careful psychiatric evaluation and close follow-up to adequately diagnose fliers with flight phobic reactions, as well as establishing adequate medical and/or psychological treatment.


Subject(s)
Aerospace Medicine , Aircraft , Anxiety , Fear , Phobic Disorders/epidemiology , Adolescent , Adult , Aviation , Comorbidity , Female , Humans , Male , Middle Aged , Spain/epidemiology , Workforce
13.
Endocrinology ; 146(2): 666-74, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15514084

ABSTRACT

LH plays a relevant role in folliculogenesis, ovulation, and luteinization. Although ornithine decarboxylase (ODC), a key enzyme in polyamine biosynthesis, is a target of LH in the ovary, the functional significance of ODC induction has remained elusive. Our study reveals that the blockade of the induction of ovarian ODC by means of the specific inhibitor alpha-difluoromethylornithine (DFMO) affects folliculogenesis and luteinization. In immature female mice, DFMO was found to inhibit ovarian growth, the formation of Graafian follicles, and the secretion of progesterone and estradiol. In adult cycling females, the administration of DFMO on the evening/night of proestrus markedly decreased plasma progesterone levels at diestrus, which was associated to the decrease in the expression of steroidogenic factor 1, cytochrome cholesterol side chain cleavage enzyme, and steroidogenic acute regulatory protein in the ovary and to a reduced vascularization of the corpora lutea. These effects were not reverted by the administration of gonadotropins or prolactin. ODC immunoreactivity was also stimulated by LH in theca and granulosa cells of antral follicles but not in preantral follicles. Overall, these experiments demonstrate that elevated ODC values found in the ovary of immature and adult mice play a relevant function in ovarian physiology and that ODC/polyamines must be considered as important mediators of some of the effects of LH on follicular development and luteinization.


Subject(s)
Luteinization/metabolism , Ornithine Decarboxylase/metabolism , Ovarian Follicle/enzymology , 3-Hydroxysteroid Dehydrogenases/genetics , Age Factors , Animals , Aromatase/genetics , Cholesterol Side-Chain Cleavage Enzyme/genetics , DNA-Binding Proteins/genetics , Eflornithine/pharmacology , Enzyme Inhibitors/pharmacology , Estradiol/blood , Female , Follicle Stimulating Hormone/pharmacology , Homeodomain Proteins , Luteinizing Hormone/pharmacology , Mice , Mice, Inbred Strains , Ornithine Decarboxylase Inhibitors , Ovarian Follicle/growth & development , Phosphoproteins/genetics , Progesterone/blood , RNA, Messenger/analysis , Receptors, Cytoplasmic and Nuclear , Signal Transduction/physiology , Steroidogenic Factor 1 , Transcription Factors/genetics
14.
Nitric Oxide ; 8(3): 182-201, 2003 May.
Article in English | MEDLINE | ID: mdl-12826067

ABSTRACT

Changes in the nitric oxide (NO) system of the rat cerebral cortex were investigated by immunohistochemistry, immunoblotting, and NO synthase (NOS) activity assays in adult rats submitted for 30 min to hypoxia, in a hypobaric chamber at a simulated altitude of 38,000 ft (11000 m) (154.9 mm Hg). The cerebral cortex was studied after different survival times, 0 and 24 h, 5, 8, 15, and 30 days of reoxygenation. This situation led to morphological alterations in the large type I interneurons, as well as immunoreactive changes in the appearance and number of the small neurons (type II), both containing neuronal NOS (nNOS). Some of these small neurons showed immunoreactive cytoplasm and short processes; others, the more numerous during all reoxygenation periods, contained the immunoreactive product mainly related to a perinuclear ring. Ultrastructurally, these small neurons exhibited changes in nuclear structures as in the shape of the nuclear membrane, in the distribution of heterochromatin, and in the nucleolar morphology. The reaction product for nitrotyrosine, as a marker of protein nitration, showed modifications in distribution of the immunoreactive product. No expression was found for inducible NOS (iNOS). All these modifications were accompanied by increased nNOS and nitrotyrosine production as demonstrated by Western blotting and calcium-dependent activity, returning to control conditions after 30 days of reoxygenation, suggesting a reversible NO mechanism of action.


Subject(s)
Brain Chemistry , Hypoxia/metabolism , Nitrergic Neurons/metabolism , Nitric Oxide/metabolism , Proteins/metabolism , Tyrosine/analogs & derivatives , Animals , Atmospheric Pressure , Cerebral Cortex/blood supply , Cerebral Cortex/enzymology , Cerebral Cortex/metabolism , Immunohistochemistry , Male , Nitric Oxide Synthase/metabolism , Nitric Oxide Synthase Type I , Nitric Oxide Synthase Type II , Rats , Rats, Wistar , Tyrosine/analysis
15.
Med Clin (Barc) ; 120(15): 574-5, 2003 Apr 26.
Article in Spanish | MEDLINE | ID: mdl-12729525

ABSTRACT

BACKGROUND AND OBJECTIVE: The frequency and circumstances associated with drugs-induced bradiarrhythmia (DB) causing hospital admission are little known. PATIENTS AND METHOD: Retrospective analyses of DB in Cardiology (CD) and Internal Medicine (IMD) Departments of a 3rd level hospital over two consecutive years. RESULTS: We detected 83 cases (mean age: 72.68, 75.9% women). Most frequent DB was slow atrial fibrillation (55.4%). DB were due to the use of one drug in 41 cases and to an association in 42 cases. Most frequently involved drug was digoxine (62.7%). DB were due to the use of one drug in 41 cases and to an association in 42 cases. Most frequently involved drug was digoxine (62.7%), which was commonly associated with another drug (69.3%). Most frequent pharmacological associations were negative chronotropic drugs (57.1%) followed by their association with a diuretic and/or an angiotensin converting enzyme inhibitor (42.8%), causing renal failure and/or potassium imbalance. CONCLUSIONS: Drugs-induced bradiarrhythmia is a frequent cause of hospital admission in aged people, especially women, and is frequently due to drugs associations and/or renal failure.


Subject(s)
Arrhythmias, Cardiac/chemically induced , Arrhythmias, Cardiac/rehabilitation , Bradycardia/chemically induced , Bradycardia/rehabilitation , Hospitalization/statistics & numerical data , Patient Admission/statistics & numerical data , Aged , Arrhythmias, Cardiac/epidemiology , Bradycardia/epidemiology , Female , Humans , Male , Retrospective Studies , Spain/epidemiology
16.
Med. clín (Ed. impr.) ; 120(15): 574-575, abr. 2003.
Article in Es | IBECS | ID: ibc-23729

ABSTRACT

FUNDAMENTO Y OBJETIVO: La información sobre las bradiarritmias secundarias a fármacos (BRSF) causantes de ingresos hospitalarios es escasa. El objetivo de este trabajo fue estimar la magnitud y las consecuencias de la BRSF en nuestro ámbito. PACIENTES Y MÉTODO: Análisis retrospectivo de los pacientes con BRSF ingresados en los Servicios de Cardiología (SC) y Medicina Interna (SMI) de un hospital terciario durante dos años consecutivos. RESULTADOS: Hallamos 83 casos (edad media: 72,68 años), de los que el 75,9 por ciento correspondió a mujeres. La BRSF más frecuente fue la fibrilación auricular (FA) lenta (55,4 por ciento). Dichas BRSF se debieron a un fármaco en 41 casos y a una asociación en 42. La digoxina fue el fármaco más frecuentemente implicado (62,7 por ciento), a menudo asociada a otro fármaco (69,3 por ciento). La asociación más frecuente fue la de fármacos cronotropos negativos (58 por ciento), seguida de la de éstos con un diurético y/o inhibidor de la enzima conversiva de la angiotensina (IECA) (42,8 por ciento), condicionando insuficiencia renal y/o alteraciones del potasio. CONCLUSIONES: Las BRSF son un frecuente motivo de ingreso en personas mayores, sobre todo mujeres, a menudo debido a asociaciones farmacológicas y/o insuficiencia renal (AU)


Subject(s)
Aged , Male , Female , Humans , Spain , Patient Admission , Retrospective Studies , Bradycardia , Arrhythmias, Cardiac , Hospitalization
17.
Rev Esp Cardiol ; 56(1): 107-10, 2003 Jan.
Article in Spanish | MEDLINE | ID: mdl-12550008

ABSTRACT

The diagnosis of Brugada syndrome, or right bundle-branch block with an elevated ST segment and negative T waves in V1-3, is obscured by the transitory normalization of the electrocardiogram, which can be unmasked by administering sodium-channel blockers. It has been recently reported that the condition can be underdiagnosed if only conventional precordial leads are used. We present the cases of two asymptomatic patients, a mother and son, with a family history of sudden cardiac death in first-degree relatives. Baseline ECGs obtained in conventional leads and one and two intercostal spaces above conventional electrode sites were similar, normal in the mother and saddle-like in the son. A flecainide stress test elicited the characteristic pattern of Brugada syndrome in both patients, but only in the high leads. Pharmacological stress testing with conventional precordial lead recordings does not rule out Brugada syndrome. We recommend that ECG recordings should include leads in the second and third intercostal spaces.


Subject(s)
Bundle-Branch Block/complications , Bundle-Branch Block/diagnosis , Death, Sudden, Cardiac/etiology , Adult , Anti-Arrhythmia Agents , Bundle-Branch Block/genetics , Death, Sudden, Cardiac/prevention & control , Electrocardiography , Exercise Test/methods , Female , Flecainide , Humans , Male , Pedigree , Sodium Channel Blockers , Syndrome , Ventricular Fibrillation/diagnosis , Ventricular Fibrillation/genetics , Ventricular Fibrillation/physiopathology
18.
Rev. esp. cardiol. (Ed. impr.) ; 56(1): 107-110, ene. 2003.
Article in Es | IBECS | ID: ibc-17771

ABSTRACT

El diagnóstico del síndrome de Brugada, bloqueo de rama derecha con segmento ST elevado y ondas T negativas de V1-3, se encuentra dificultado por la normalización transitoria del electrocardiograma, y puede ser desenmascarado por los bloqueadores de los canales de sodio. Recientemente se ha comunicado su posible infravaloración con la sola utilización de las derivaciones precordiales convencionales. Presentamos los casos de 2 pacientes asintomáticos, madre e hijo, con antecedentes familiares de primer grado de muerte súbita. Los ECG basales en las derivaciones precordiales convencionales y en uno y dos espacios intercostales por encima fueron similares, normal en la madre y en 'silla de montar' en el hijo. Tras test de flecainida, ambos desarrollaron el patrón electrocardiográfico típico del síndrome de Brugada exclusivamente en las derivaciones superiores. El test de provocación farmacológico con las derivaciones convencionales no descarta el síndrome de Brugada, y es necesario incluir sistemáticamente las derivaciones precordiales en el segundo y tercer espacios intercostales (AU)


Subject(s)
Adult , Male , Female , Humans , Syndrome , Ventricular Fibrillation , Death, Sudden, Cardiac , Pedigree , Sodium Channel Blockers , Anti-Arrhythmia Agents , Bundle-Branch Block , Electrocardiography , Flecainide , Exercise Test
19.
Life Sci ; 71(13): 1511-21, 2002 Aug 16.
Article in English | MEDLINE | ID: mdl-12127906

ABSTRACT

The influence of different neural systems that modulate GnRH secretion by hypothalamic neurons was investigated in mice exposed to hypokalemic conditions, in which the pulsatile release of GnRH has been shown to be altered and associated with a significant decrease of plasma sex steroids. Our results demonstrate that the potentiation of the inhibitory pathways mediated by opiates and GABA may be implicated in the decrease of sex hormones secretion produced by hypokalemia since treatment with higher doses of naloxone or flumazenil are required to restore progesterone or testosterone levels in potassium deficient mice. The combination treatment of prazoxin and naloxone suggests that the inhibitory action of opiates take place through its action on noradrenergic neurons. It is also possible that the inhibition of GnRH release could be due to a decrease in the tonic stimulatory action of noradrenergic pathway implicated in the control of GnRH release. Our results also reveal that it is unlikely that the glutamatergic system may play any relevant direct role in the decrease of sex steroid secretion observed in potassium deficient mice. Finally, these results together with the normal pattern of estradiol levels found along the estrus cycle in potassium deficient mice indicate that factors different from estradiol and acting on neural systems implicated in the regulation of GnRH-secreting neurons participate in the generation of the preovulatory surge of GnRH.


Subject(s)
Gonadotropin-Releasing Hormone/metabolism , Hypothalamus/physiology , Luteinizing Hormone/metabolism , Potassium Deficiency/metabolism , Synaptic Transmission/physiology , Testosterone/metabolism , Animals , Drug Therapy, Combination , Estradiol/blood , Estrous Cycle/blood , Female , Flumazenil/pharmacology , GABA Modulators/pharmacology , Hypokalemia/blood , Hypothalamus/drug effects , Luteinizing Hormone/blood , Mice , Naloxone/pharmacology , Narcotic Antagonists/pharmacology , Neurotransmitter Agents/pharmacology , Norepinephrine/pharmacology , Testosterone/blood
20.
Biochem Biophys Res Commun ; 293(1): 106-11, 2002 Apr 26.
Article in English | MEDLINE | ID: mdl-12054570

ABSTRACT

Ovarian progesterone secretion during the diestrus stage of the estrous cycle is produced by luteal cells derived from granulosa and thecal cells after the differentiation process that follows ovulation. Our results show that blockade of the preovulatory rise of ovarian ornithine decarboxylase (ODC), a key enzyme in polyamine biosynthesis, by treatment with the specific inhibitor alpha-difluoromethylornithine (DFMO) leads to a significant decrease in the ovarian progesterone content and a dramatic fall in the plasma levels of this hormone during the following diestrus. The same inhibition was produced in spite of the fact that both luteinizing and follicle stimulating hormones were given concomitantly with DFMO. On the other hand, the acute rise in the plasma progesterone levels observed after administration of human chorionic gonadotropin to mice at different periods of the estrous cycle was not affected by DFMO administration. Our results indicate that although elevated levels of ODC are not required for acute ovarian steroidogenesis, the preovulatory peak of ovarian ODC activity observed in the evening of proestrus may be critical for the establishment of a constitutive steroidogenic pathway and progesterone secretion by the corpus luteum during the diestrus stage of the murine estrous cycle.


Subject(s)
Corpus Luteum/metabolism , Estrus/physiology , Ornithine Decarboxylase/metabolism , Ovary/enzymology , Progesterone/metabolism , Animals , Eflornithine/pharmacology , Enzyme Inhibitors/pharmacology , Female , Follicle Stimulating Hormone/pharmacology , Luteinizing Hormone/pharmacology , Mice , Ornithine Decarboxylase Inhibitors , Ovulation/physiology
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