PubMed Health⌕ Search

Biomedical subjects

M Vijande

Publications and source records attributed to M Vijande.

At least 19 recordsLinked to original sources
PubMed2004

Thirst changes in offspring of hyperreninemic rat dams.

The aim of this study was to investigate the changes in thirst dependence on the renin-angiotensin system (RAS), in offspring of hyperreninemic, hyperdipsic, and natriophilic rat dams. Female rats underwent a partial aortic ligature between the renal arteries (PAL) or were sham-operated (SHAM). At 6 days of age, offspring of PAL (O-PAL) and SHAM (O-SHAM) dams were injected with isoproterenol (subcutaneously, 500 microg/kg body weight) or vehicle. Pretreatment with captopril (intraperitoneally, 50 mg/kg) on isoproterenol-induced thirst was also studied. Plasma renin activity in dams and hematocrit and osmolality in pups were measured. O-PAL had a greater water intake than O-SHAM. However, they responded similarly to isoproterenol or isoproterenol with captopril pretreatment. Only minor differences in hematocrit and osmolality were found between O-SHAM and O-PAL rats after isoproterenol or vehicle treatment. Beta-adrenergic or angiotensinergic responsivity seems not to be altered in offspring of hyperrenimic, hyperdipsic, and natriophilic dams. Nevertheless, other thirst responses of offspring may be critically dependent upon uterine conditions.

Animals↗
PubMed2003

Quantitative histochemical assessment of oxidative metabolism in the subfornical organ after partial aortic ligature in rats.

Circumventricular organs are considered to be involved in hydromineral homeostatic responses. In this study we used quantitative histochemistry of cytochrome oxidase to evaluate the oxidative metabolic activity of the subfornical organ of rats with a partial aortic occlusion. These rats showed a significant increase in water intake from the second day after the ligature, while natriophilia was already significant on the first day. Greater levels of cytochrome oxidase activity were found in subfornical organs of partial aortic ligated rats when compared with control, providing further evidence for the involvement of this circumventricular structure in fluid homeostasis at least in this hyperdipsic, hypernatriophilic, hyperreninemic and hypertensive experimental model.

Animals↗
PubMed2001

Partial aortic ligature induces selective long-term c-fos like immunoreactivity in the organum vasculosum of the lamina terminalis, medial preoptic area and choroid plexus in the rat.

Partial aortic ligature causes an increase in water and sodium intake. Circumventricular brain regions are known to be involved in the regulation of these processes. In this work we use c-fos-like immunoreactivity to detect active areas involved in the long-term control of increased water and sodium intake due to partial aortic ligature. A significant increase in water intake was found on the first day after the induction, while natriophilia was observed on the fourth day. c-fos-like immunoreactivity was found selectively in the subfornical organ, the organum vasculosum of the lamina terminalis, the medial preoptic area, and the choroid plexus of the third ventricle. Present results provide further evidence for the involvement of circumventricular organs and the preoptic area in the regulation of hydromineral balance. Moreover, they suggest a maintained and long-term regulation of sodium intake by these same brain areas.

Animals↗
PubMed2000

Adult offspring long-term effects of high salt and water intake during pregnancy.

Offspring from dams subjected to hypereninemia, hyperdipsia, and natriophilia by partial aortic ligation (PAL) showed a long-term modification of their ingestive behavior. These rats, upon reaching adulthood, showed an increased appetite for low-concentration saline solutions (0.1 M) when compared to control rats. They also presented a high intake of a medium concentration NaCl solution (0.45 M) after having been offered a very aversive highly concentrated NaCl solution (1.0 M) along with water for 2 days. An increase was also observed in their salt/water intake ratio following two different thirst challenges, 24-h fluid deprivation or sodium depletion by furosemide treatment. The demonstration of the long-term effect of pregnancy history on salt preference in adult offspring draws attention to the possible physiopathological aspects that may be of relevance, considering the well-established relationship between salt intake and hypertension, a disease most commonly occurring in the adult and aged population.

Age Factors↗
PubMed1998

Effect of castration and gonadal hormones on insulin-induced drinking.

Female Wistar rats in any of the estrual phases have been shown to drink significantly more water than males (p < 0.05), after a single I.P. insulin injection (5 U/kg b.wt.). Sexual differences in insulin-induced drinking persisted after castration when it was made in adult rats (4.6 +/- 1.2 ml/2 h, males = 8; vs. 13.0 +/- 3.1 ml/2 h, females = 8; p < 0.05). On the other hand, when animals were castrated before puberty or when newborn, sexual differences in insulin-induced drinking disappeared. Hence, insulin-induced drinking seems to be a sex-dependent phenomenon that differentiates just before or during puberty since it is abolished by castration prior to sexual maturation. Sex hormone administration in male and female rats castrated at different ages showed a variety of actions on insulin-induced drinking. A pattern emerged showing that androgenized (testosterone treated) rats drank usually less in response to insulin than estrogen-treated rats (independent of their genetic sex). According to the above results, we can conclude that insulin-induced drinking is a phenomenon sensible to gonadal hormones, both by conditioning the differentiation of some physiological structure or mechanisms that underlay drinking behavior in that paradigm and by a direct action on these or other related mechanisms.

Animals↗
PubMed1996

Increased salt preference in adult offspring raised by mother rats consuming excessive amounts of salt and water.

This study was designed to evaluate the effects of an early high-salt environment on the maternal and the young offspring physiology and on the adult offspring sodium appetite. Twenty-five-adult female Wistar rats were pseudorandomly divided into two groups. Twelve animals underwent a partial ligature of their abdominal aorta (PAL). Once polydipsia and sodium appetite (tested by measuring water and a 2.7% NaCl intakes) developed, they were mated. The other 13 rats (SHAM) were sham-operated and also mated. Throughout pregnancy and lactation, water and salt intake of PAL rats was consistently and significantly higher than that of the Sham. On gestation day 20, amniotic fluid and maternal plasma sodium concentration of PAL and Sham rats did not differ. Sodium concentration in the milk of the lactating PAL group was elevated (P < 0.05) on day 20 after delivery. At 0, 10 and 21 days of age, plasma sodium concentration of PAL offspring (PAL-O) and Sham offspring (Sh-O) were not significantly different. At 90 days of age, the salt preference of PAL-O rats was greater than that of Sh-O rats after 7 days of sodium deprivation (P < 0.01).

Aldosterone↗
PubMed1996

Changes of blood pressure responsiveness in rats exposed in utero and perinatally to a high-salt environment.

We tested the hypothesis that the pressor responses to angiotensin II could be influenced by an early salt exposure. Twenty-five adult female rats were pseudorandomly divided in two groups. Twelve animals underwent a partial ligature of their abdominal aorta (PAL). Once polydipsia and sodium appetite developed, these rats were mated. The other group (13 rats) was sham-operated (Sham) and mated. Throughout pregnancy and lactation, water and 2.7% NaCl solution intakes differed between the two groups of mother rats. PAL offspring (PAL-O; n = 14), and Sham-operated offspring (Sh-O; n = 10), were maintained on a solid diet containing 1% NaCl, tap water and a 2.7% NaCl solution. At 90 days of age, pressor responsiveness to intravenous angiotensin II (50, 100 and 200 ng) was assessed in anesthetized rats. The pressor responses to 50 and 200 ng angiotensin II were significantly greater in PAL-O rats than in Sh-O rats. These results support the hypothesis of a modulation of cardiovascular responsiveness or its underlying mechanisms by an early high salt environment.

Angiotensin II↗
PubMed1996

Factors influencing the return to work of patients after hip replacement and rehabilitation.

OBJECTIVE: To determine the incidence of medical and sociocultural factors on the return to work of patients after hip replacement and rehabilitation treatment. DESIGN: Case review. Frequency and association of variables' analysis. SETTING: The rehabilitation unit of a general hospital in Oviedo (Spain). This setting is a part of an institutional referral center and is the only state-owned hospital that provides rehabilitation treatment for hospitalized patients from a rural and urban area of about 1,000,000 inhabitants. PATIENTS: 747 patients of both sexes, all of them working before receiving treatment, age range 18 to 64 years. MAIN OUTCOME MEASURES: Relationship of several variables: age, sex, habitat, level of education, type of work, underlying illness, walking ability, pain, and type of social security versus return to work. RESULTS: At discharge, 25% of patients return to work. There is a significant association (p < .001) between return to work and any of the following variables: underlying illness, kind of work, walking ability, habitat, and educational level. CONCLUSION: This physiopathology of symptoms and signs of the patients is not the unique indicator of whether a person will continue working after hip replacement and rehabilitation treatment. Extramedical factors, such as social status, kind of work, and cultural background, are very influential.

Adolescent↗
PubMed1996

Dentoalveolar stress from bodily tooth movement at different levels of bone loss.

This study was undertaken to determine the stress that appears in the tooth, the periodontal ligament, and the alveolar bone, when a couple and horizontal forces were applied to obtain the bodily movement of a lower digitalized canine and its changes depending on the degree of loss of the supporting bone. The analysis of tensions was carried out by means of the finite element method (FEM) with no bone loss and after reducing the support bone 2, 4, 6, and 8 mm. False color three-dimensional images indicating intensity of stress (tensile and compressive) and extension are generated. After the application of the forces in the model without bone loss, a rather uniform distribution of stress is observed. When the bone loss is 2 mm, an increased stress in the levels next to the alveolar crest is already apparent. After 4, 6, and 8 mm of bone support reduction, a change of the sign and an increment of the magnitude of stress in the lowest levels occurs.

Alveolar Bone Loss↗
PubMed1995

Trans-European medical education: experience of the Faculty of Medicine of Oviedo.

The European Community has played a key role in organizing student mobility programmes and in emphasizing the need for a European medical culture. The need for a common core of medical principles and efforts to strengthen inter-European cooperation nurture the philosophy of these exchanges. The Faculty of Medicine of Oviedo has been working on student mobility programmes for the last 7 years. As a result of this activity, about four hundred medical students have participated in various exchanges. This experience is highly positive both for the students and for the institutions taking part in it. The students have the chance to become acquainted with a different country, language, culture and medical training system. Meanwhile, the institutions benefit from their students' experience as well as having the opportunity of starting further cooperative programmes.

Education, Medical, Undergraduate↗
PubMed1995

Changes in the upper airway of patients who wear a modified functional appliance to treat obstructive sleep apnea.

This study was designed to investigate changes that occur in the upper airway of patients with obstructive sleep apnea who use a modified functional appliance. The experimental group included 10 men, all diagnosed with obstructive sleep apnea. Nuclear magnetic resonance imaging was carried out on each patient. One image was taken when the patient was in maximum habitual occlusion and another was taken while the patient wore the appliance. From the images gained, a three-dimensional reconstruction of the upper airway from the palatal plane was achieved. The images revealed statistically significant increases in the volume of the upper airway with the use of a modified functional appliance. Three-dimensional studies of the upper airway show greater detail and therefore seem likely to have more validity than two-dimensional studies.

Adult↗
PubMed1993

Initial stress induced in periodontal tissue with diverse degrees of bone loss by an orthodontic force: tridimensional analysis by means of the finite element method.

This study was undertaken to determine the stress that appears in tooth, periodontal ligament and alveolar bone, when a labiolingual force of 100 gm is applied in a labiolingual direction in a midpoint of the crown of an inferior digitalized canine, and its changes depending on the degree of loss of the supporting bone. The analysis of tensions was carried out by means of the finite element method (FEM) for a normal case and after reducing the periodontal support bone 2, 4, 6, and 8 mm. Three-dimensional images in false color in which intensity of tensions and its areas of extension are generated. Special attention was paid to changes at level D (apical transversal section) to which maximum, mean, minimum, and Von Mises tensions are calculated. After applying the labiolingual force in the canine, a progressive increase of the stress in the labial and lingual zones of the tooth, periodontal membrane and alveolar bone was observed when the alveolar bone was reducing. In the mesial and distal zones, no compensating forces appear, which could provoke a tooth rotation during the tipping movements.

Alveolar Bone Loss↗
PubMed1993

Transcranial oblique lateral radiography to verify the position of the mandibular condyles with the use of functional appliances.

By means of standardized transcranial oblique lateral (TOL) radiographs, the position of the mandibular condyles in the glenoid fossae of 14 patients with Class II division 1 malocclusion was studied at the beginning of treatment with or without functional appliances placed in position, and also at the end of treatment. A significant increase in the distance between the upper point of the condyle and the glenoid fossa was found when the appliance was worn for the first time. This displacement was found to disappear at the end of the treatment even when the appliance was placed in position.

Activator Appliances↗
PubMed1992

Williams syndrome. Report of a case.

Williams syndrome is a rare anomaly consisting of idiopathic hypercalcemia that is normally accompanied by aortic stenosis, moderate mental retardation, and a characteristic elfin face. Because persons with this syndrome have severe dental abnormalities, it is in the dental or orthodontic clinic that the disease can eventually be detected. A unique case of this type is reported.

Aortic Valve Stenosis↗
PubMed1992

Immunohistochemical localization of epidermal growth factor and its receptor during odontogenesis in the rat.

The expression of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFr) in developing teeth has been immunohistochemically studied in rat embryos (E-16 to E-21). Both EGF and EGFr showed a similar pattern of distribution. A very weak immunostaining was observed in the dental germ cells during the bud, cap, and bell teeth stages, as well as in few ectomesenchymal cells. In developed, but not erupted teeth, a moderate immunoreactivity for EGF and EGFr was present in the odontoblasts, in the ameloblasts and in the internal epithelial cells, but it was stronger in the dentine. In addition, the presence of EGF/EGFr was also observed in the intercalated ducts of salivary glands, primarily the submaxillary gland, in the maxillary bone cells, and in the cells of the peripheral and central nervous system. These results suggest that EGF has little or no effect during the early periods of tooth differentiation, whereas it is probably involved in the production of dentine. Moreover, EGF/EGFr seem to participate in the maturation and differentiation of other embryonic tissues such as tissues of the nervous system and bone.

Ameloblasts↗
PubMed1992

Densitometric evaluation of changes in the soft tissue of the chin and the lower lip during the treatment of Class III malocclusion.

The aim of this study was to use densitometry of lateral skull teleradiographs to evaluate the changes that occurred in the lower lip and chin after orthodontic or orthodontic-surgical treatment of Class III malocclusion. Forty teleradiographs from 20 patients with mandibular prognathism were made at the beginning and end of treatment. In ten of these patients the treatment was exclusively orthodontic with an edgewise appliance, and in another ten the treatment was orthodontic with a straight wire appliance combined with orthognathic and mentoplastic surgery. In the patients who were only treated orthodontically, a significant increase in density of the lower lip and the chin was found after treatment. This seemed to be related to an increase of muscular tension in these areas. Patients treated with orthognathic surgery and the straight wire appliance showed a decrease in density of the chin after treatment, but not of the lip. This can be interpreted as a consequence of muscular normalization after this procedure was accomplished.

Absorptiometry, Photon↗