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Biomedical subjects

R Santana

Publications and source records attributed to R Santana.

15 recordsLinked to original sources

Effect of the intracerebroventricular administration of GR 113808, a selective 5-HT4 antagonist, on water intake during hyperosmolarity and hypovolemia.

We demonstrate here that acute third ventricle injections of GR 113808, a highly selective 5-HT4 antagonist, decrease water intake induced by a previous salt load while potentiating drinking elicited by hypovolemia induced by previous subcutaneous administration of polyethylene glycol in male Wistar rats (200 +/- 20 g). At the dose of 160 nmol/rat, third ventricle injections of GR 113808 induced a significant reduction of water intake in salt-loaded animals after 120 min as compared to salt-loaded animals receiving third ventricle injections of saline (salt load + GR = 3.44 +/- 0.41 ml, N = 12; salt load + saline = 5.74 +/- 0.40 ml, N = 9). At the dose of 80 nmol/rat, GR 113808 significantly enhanced water intake in hypovolemic animals after 120 min as compared to hypovolemic animals receiving third ventricle injections of saline (hypovol + GR = 4.01 +/- 0.27 ml, N = 8; hypovol + saline = 2.41 +/- 0.23 ml, N = 12). We suggest that central 5-HT4 receptors may exert a positive drive on water intake due to hyperosmolarity and a negative input on drinking provoked by hypovolemia.

Animals↗

[Manufacture of a freeze dried stew for mountaineers].

The mountaineers use to eat at the evening dinner which ought to fulfil the following requirements: it should be nutritive and have an adequate composition, a small volume and should be light, keeping a good quality during a long period of time. Its preparation must be fast and easy, being well accepted by the group of mountaineers. A stew of common use in Chile based on meat and vegetables was elaborated, known as < >, a typical chilean stew. It was dehydrated by freeze-drying, a process based in the freezing and subsequent ice sublimation of the product, achieving a very high retention of both sensory and nutritional qualities. The final product corresponded to individual portions of 60g of Charquican which was vacuum-packed in a coextrude polyamide-polyethylene pack, which protects from the moisture and oxygen. It was used an outer packaging of plastic-coated aluminum foil, in order to protect him from the light. Controls of the optimized product indicate a 6,7% of humidity with an aw value of 0,26. The chemical composition is nutritionally adequate, with a 45.6% of carbohydrates, 5,0% of lipids and 29,5% of proteins. It presents a sensory quality with typical characteristics which ranged from good to very good. The microbiological quality meets the Standards of the Chilean Sanitary Regulation for Foods. The total plate count and the molds and yeasts count were below the proposed limits. The study of the Charquican s shelf life performed at environmental storage conditions (20-25 degrees C and 50-55 RH) showed that the microbiological quality is mantained without significant differences. The sensory quality presents a slight and gradual decrease until the average score fo 6,7 after 200 days storage. The evaluation with excursionists at the mountains, showed the excellent acceptability and the good reliability of the product.

Chile↗

[Development and optimization of an isotonic sports drink].

Within a research program on food products for athletes starting from natural apple concentrate, the design, manufacture and control of isotonic beverages, was undertaken. The dilution conditions for the apple concentrate were established studying several salts combinations which will supply those electrolytes that are eliminated through sweat and have to be replenished. They are sodium, potassium, chloride, magnesium and calcium in concentrations such as to supply an osmotic pressure similar to that observed in blood. The addition of a premix of vitamins (B1, B2, B6, B12, C, E, folic acid, niacin, pantothenic acid and biotin) in several levels of the Recommended Daily Allowance (RDA) (100, 75, 62.5, 60 and 30% of the RDA) was assayed. The obtained formula tasted salty and medicine-like, therefore the vitamin content had to be reduced, supplying 30% of the RDA in a premix constituted by those vitamins which are the most important for physical activity (B1, B2, B6 and C). The quality of the formula was optimized considering variables such as flavor, color and maltodextrin levels by using methods of sensory evaluation. In the elaborated beverage controls such as pH, acidity, total solids (degree Bx), relative density and soluble solids/acidity ratio complying with the corresponding standards, were carried out. In addition, chemical composition, caloric value, microbiological and sensory quality, were controlled. The fruit juice was packed in a 250 ml self-supporting"Doy-Pack"-like bag. Both, microbiological and sensory quality were good, and the caloric value was 101.18 Kcal/250ml. Shelf life studies at two different temperature conditions 15-25 degrees C and 3-5 degrees C, were carried out. The limiting factor was flavor which defined a shelf life of at least 3 months, stored at refrigeration temperature (3-5 degrees C). The formulated beverage supply the electrolyte concentrations which allows to be characterized as isotonic beverage, recommended for athletes.

Beverages↗

[Development of soy-based protein candy bars for athletes].

Two varieties of soy-based candy bars were developed for sportsmen who need a higher protein intake. The two varieties, almond and nut, were covered with chocolate. The ingredients used were isolated soy protein, texturized soy flour, milk solids, cocoa powder, toasted oat, nuts, almonds, authorized flavors, preservants and antioxidants. Controls were carried out in the optimized products, and the results indicate a very good sensory and microbiological quality. The average nutritional composition of both varieties is: 12,4% proteins, 9% lipids and 58,7% carbohydrates, and the caloric value is 375,2 kcal/100 g. A shelf-life study was performed at room temperature with the candy bars packed in an aluminium foil. Determining that the quality remains without significant changes during 30 days for the nut candy, and at least for 60 days for the almond candy bar.

Animals↗

[Development of an energy food for athletes].

The energetic requirements of sportsmen fluctuates between 3500 and 8000 Kcal/day. In order to fill these needs it is necessary to have new alternative products which provide the extra required energy. For this purpose a confectionary was designed and elaborated consisting of five different bars, made of natural raw materials (dehydrated fruits, milk, eggs, nuts, fat), which supply an important quantity of fats and carbohtdrates, minerals, and vitamins. The confectioned bars were: papaya, hazelnut, almond, apple and orange. These bars are supposed to be eaten between meals as a complement of the nutrients of the usual diet. The production process is an adaptation of the traditional confectionary techniques and was improved for the 5 bars. The production process of the coating sheet (oblate) was also studied. The controls showed that all the bars had a good microbiological quality and an excellent sensory quality. The humidity fluctuated between 6.85 and 13.66%., with an aw of 0.795. The caloric distribution per cent was 8:40:52. The energetic supply was 520 Kcal/100g; so, the ingest of two displays covers between 25-30% of recommended intake for the most frequently practiced sports. The shelf life studies of the product stored in ambiental conditions (20-25 degrees C and 55-60% RH) showed that the product without additives maintained its good quality up to 60 days. The product plus preservative as well as plus antioxidant stays without quality modifications up to at least 120 days, neither rancid odor no rancid flavor was detected. So, we conclude that it is nor necessary to add any antioxidant. The double sheet polypropilene package film showed very good characteristics in protecting the quality of the product.

Antioxidants↗

[Functional evaluation of a nutritional energy supplement in athletes].

A nutritional caloric supplement as bar in 5 different flavours was evaluated in 9 sportsmen that ate daily 1040 Kcal/100 g extra during 8 weeks. Anthropometric measurements were used for weight, body fat, lean body mass and functional test for VO2 max, anaerobic threshold (AnT) and anaerobic power (AnP). Both tolerance and acceptability were evaluated too. Other similar sportsmen group was employed as control. Positives answers were registered in VO2 max (8.74%) and AnP (p < or = .04), meanwhile the rest of parameters remained without alterations, the same of control group. Test TAT evidence a high preference and a tolerance without deleterious effect. In conclusion, the product evaluated is an excellent ergogenic aid in effort with elevated energetic demand.

Adult↗

Tracheal agenesis: an unresolved problem.

A case of tracheal agenesis diagnosed at birth is discussed in which surgical correction was attempted. Both main bronchi were divided and anastomosis of the main right bronchus to the larynx was attempted, after intrapericardial release of the right lung and severing of the lower pulmonary ligament: bronchoplastic reconstruction of the trachea was impossible. We think that tracheal agenesis, a rare cause of respiratory distress in the newborn, has no suitable therapy today. It is justified to attempt surgical correction if any promising device is at hand or if any doubt exists that an uncorrectable situation is present.

Humans↗

The utility of electromyographic biofeedback in the treatment of conversion paralysis.

Conversion paralysis has a poor prognosis when there is evidence of nonresponse to previous treatment, long duration, and secondary atrophy of the "paralyzed" muscles. The authors present four such cases in which conversion paralysis was treated successfully by means of electromyographic (EMG) biofeedback. Each of the four patients also suffered from a chronic pain condition. Results from statistical analyses indicated that the four patients demonstrated significant improvement in the functional capacity of the "paralyzed" muscles as measured by isometric maximum voluntary contraction and EMG activity. The improvements occurred without explicit psychotherapy and suggest that behavioral modification techniques alone may be helpful in such cases.

Adult↗

Glioblastoma multiforme presenting as stroke: an electrophysiological and clinicopathological case report.

A 55-year-old man having hemiplegia after the sudden onset of a stroke was referred for rehabilitation. Cerebral angiography had demonstrated occlusion of the left middle cerebral artery and steroid therapy had been started. Attempted tapering of the steroid therapy on admission for rehabilitation resulted in the patient having severe headaches and confusion. Blink reflex evaluation, somatosensory cerebral evoked potential determinations and visual evoked responses were all consistent with a widespread process involving the parietal lobe of the patient's left cerebral hemisphere. Computerized axial tomography indicated an abnormality consistent with a space-occupying lesion. Craniotomy revealed the presence of a glioblastoma multiforme in the left cerebral hemisphere. Electrodiagnostic evaluation was entirely consistent with the operative finding of widespread involvement of the patient's left parietal lobe. Stroke patients whose conditions deteriorate over time must be serially evaluated in order to determine possible other causes of their symptoms.

Brain Neoplasms↗

Double-blind, placebo-controlled, cross-over trial of progabide as add-on therapy in epileptic patients.

In a double-blind, cross-over trial, progabide (PGB) and placebo were compared as add-on therapy in 59 patients with moderate to severe epilepsy. Eight patients did not complete the study, 4 because of adverse drug reactions (elevation of liver transaminases, 2; gastritis, 1; and acute psychosis, 1) and 4 because of administrative reasons. Among the remaining 51 patients, seizure frequency was reduced greater than 50% in 18 patients with PGB treatment and in 8 patients with placebo (p less than 0.05). The number of days with seizures was significantly (p = 0.034) reduced during PGB treatment. Both patients' and physicians' preferences at the end of the trial were in favor (p less than 0.01) of PGB. Mild clinical side effects were present in 54.7% of the patients treated with PGB and in 37.7% with placebo. Increase in liver transaminases was observed in 2 patients during the double-blind study and in 1 during the follow-up period. Our data show that PGB, as previously reported, is useful in 30-40% of patients who are not responding completely to other antiepileptic drugs (AEDs). The compound is well tolerated, but liver function must be monitored.

Adolescent↗

[Ataxia telangectasia. Probability of damaging immune mechanisms].

Twelve patients suffering from ataxia telangiectasia and relatives of three of them were studied. A late diagnosis prevailed and the neurological symptoms in some turned worse after suffering recognizable viral infections. The cellular and humoral immunodeficiencies were evaluated in each case as well as the simultaneous presence of hyperimmunoglobulinemia and/or auto-antibodies. Among the relatives, there were frequent cases of immunological and neoplastic alterations; cellular immunodeficiency was not detected. Five cases showed lung disease; four with absence of IgA, and histologic interstitial lesion detected in three of them. The hypothesis that the defect of cell immunity predisposes mulisysthemic disease and that an early diagnosis with immune reconstructive treatment can modify the evolution of the disease was considered.

Antibody Formation↗