[Artificial intelligence and its applications in medicine I: introductory background to AI and robotics]. / La inteligencia artificial y sus aplicaciones en medicina I: introducción antecedentes a la IA y robótica.

Technology and medicine follow a parallel path during the last decades. Technological advances are changing the concept of health and health needs are influencing the development of technology. Artificial intelligence (AI) is made up of a series of sufficiently trained logical algorithms from which machines are capable of making decisions for specific cases based on general rules. This technology has applications in the diagnosis and follow-up of patients with an individualized prognostic evaluation of them. Furthermore, if we combine this technology with robotics, we can create intelligent machines that make more efficient diagnostic proposals in their work. Therefore, AI is going to be a technology present in our daily work through machines or computer programs, which in a more or less transparent way for the user, will become a daily reality in health processes. Health professionals have to know this technology, its advantages and disadvantages, because it will be an integral part of our work. In these two articles we intend to give a basic vision of this technology adapted to doctors with a review of its history and evolution, its real applications at the present time and a vision of a future in which AI and Big Data will shape the personalized medicine that will characterize the 21st century.

A new scenario in metastatic renal cell carcinoma: a SOG-GU consensus.

BACKGROUND: This article describes and compares approved targeted therapies and the newer immunotherapy agents. MATERIALS AND METHODS: This article especially performs an in-depth review of currently available data for tivozanib, explaining its mechanism of action, its safety profile and its role as an efficacy drug in the management of renal cancer. RESULTS: Despite the fact that the treatment of advanced RCC has been dramatically modified in recent years, durable remissions are scarce and it remains a lethal disease. For first- and second-line therapy, there is now growing evidence to guide the selection of the appropriate treatment. CONCLUSIONS: Several TKIs are standard of care at different settings. Among those approved TKIs, tivozanib has similar efficacy than others with a better safety profile. The use of prognostic factors is critical to the selection of optimal therapy.

Identification of a mutation in the coding sequence of the human thyroid peroxidase gene causing congenital goiter.

Thyroid peroxidase (TPO) is the key enzyme in the synthesis of thyroid hormones, and the TPO defects are believed to be the most prevalent causes of the inborn errors of thyroid metabolism. We investigated an adopted boy with iodide organification defect, who presented with florid hypothyroidism at the age of 4 mo, poorly complied with thyroxine treatment, and developed a compressive goiter necessitating partial resection at the age of 12 yr. Biochemical studies revealed the absence of TPO activity in the resected tissue. Genomic DNA studies identified a 4 base-pair insertion in the eighth exon of the TPO gene, and showed that the patient was homozygous for this frameshift mutation. The direct genetic diagnosis of this mutation can be made by digestion of polymerase chain reaction products with NaeI restriction enzyme. This will help assessing its prevalence among the heterogenous genetic group of TPO defects.

Bone Density and Clinical Periodontal Attachment in Postmenopausal Women: A Systematic Review and Meta-Analysis.

Osteoporosis is a systemic skeletal disease characterized by low bone mineral density (BMD) and has been considered a risk factor for periodontal disease. The aim of this systematic review and meta-analysis was to verify the scientific evidence for the association of periodontal attachment loss with low BMD in postmenopausal women. A systematic search of the literature was performed in databases until August 2016, in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Eligibility criteria included studies that compared clinical attachment loss (CAL) between postmenopausal women with low and normal BMD. Studies using similar methodology, with lower and higher risk of bias, were pooled into 3 different meta-analyses to compare CAL among women with normal BMD, osteoporosis, and osteopenia. In the first meta-analysis, mean CAL was compared among groups. In the other 2 meta-analyses, the mean percentages of sites with CAL ≥4 mm and ≥6 mm were respectively compared among groups. From 792 unique citations, 26 articles were selected for the qualitative synthesis. Eleven of the studies were appraised as presenting low risk of bias, and the association between low BMD and CAL was observed in 10 of these studies. Thirteen cross-sectional articles were included in the meta-analysis for osteoporosis and 9 in the osteopenia analysis. Women with low BMD presented greater mean CAL than those with normal BMD (osteoporosis = 0.34 mm [95% confidence interval (CI), 0.20-0.49], P < 0.001; osteopenia = 0.07 mm [95% CI, 0.01-0.13], P = 0.02). Only studies with lower risk of bias were available for the analysis of CAL severity. Women with low BMD presented more severe attachment loss, represented as mean percentage of sites with CAL ≥4 mm (osteoporosis = 3.04 [95% CI, 1.23-4.85], P = 0.001; osteopenia = 1.74 [95% CI, 0.36-3.12], P = 0.01) and CAL ≥6 mm (osteoporosis = 5.07 [95% CI, 2.74-7.40], P < 0.001). This systematic review and meta-analysis indicates that postmenopausal women with osteoporosis or osteopenia may exhibit greater CAL compared with women with normal BMD.

A nonsense mutation causes human hereditary congenital goiter with preferential production of a 171-nucleotide-deleted thyroglobulin ribonucleic acid messenger.

Defective or impaired thyroglobulin (Tg) synthesis usually results in congenital goitrous hypothyroidism, virtual absence of Tg in thyroid tissue, and the presence of an elevated concentration of iodoalbumin. The final result of these abnormalities is a decreased rate of T3 and T4 synthesis. We have previously reported two siblings with this syndrome that was attributable to decreased levels of thyroid tissue Tg mRNA, resulting in decreased translation of a fully mature Tg. Further molecular studies in this family are the subject of this report. The Tg mRNA from normal and goitrous thyroid tissue was first reverse transcribed and divided into five overlapping portions from positions 57-8448, and the resulting cDNAs were amplified by polymerase chain reaction and analyzed by agarose gel electrophoresis. The amplification of nucleotides (nt) 4502-5184 from control thyroid tissue Tg mRNA showed a predominant fragment of 683 basepairs (bp) and a minor fragment of 512 bp. This latter fragment contained a 171-nt deletion that mapped between positions 4567 and 4737 of the Tg mRNA. In contrast, the fragment predominantly present in the congenital goiter was 512 bp. The sequencing of the 683-bp fragment revealed that the responsible mutation is a cytosine to thymine transition, creating a stop codon at position 1510. This results in loss of a TaqI restriction site. The point mutation is, thus, removed from a portion of the transcripts by the preferential accumulation in the goiter of a 171-nt-deleted Tg mRNA. The reading frame is maintained and is potentially fully translatable into a Tg polypeptide chain shorter by 57 residues. The presence of the deleted Tg mRNA in normal thyroid tissue, albeit at a low level, strongly suggests that the deleted mRNA sequence corresponds to a complete exon. Our studies suggest that the shorter, alternatively spliced Tg mRNA predominates in the goitrous tissue and probably has a shorter half-life. This would explain the tissue's low Tg mRNA levels, previously reported. Moreover, translation of the mutated transcript would generate a severely truncated Tg polypeptide with limited ability to generate thyroid hormone, resulting in congenital goitrous hypothyroidism.

A 138-nucleotide deletion in the thyroglobulin ribonucleic acid messenger in a congenital goiter with defective thyroglobulin synthesis.

Two siblings (HSN and AcSN) with congenital goitrous hypothyroidism were investigated in terms of clinical, biochemical, and molecular biology. Diagnosis of defective thyroglobulin (Tg) was based on findings of low serum T4, low normal or normal serum T3, a negative percholate discharge test, and the virtual absence of the serum Tg response to challenge by bovine TSH. Only minute amounts of Tg-related antigens were detected by RIA in the goitrous tissue (HSN, 0.82 mg/g, compared to 70-90 mg/g in normal thyroid tissue), as confirmed by sodium dodecyl sulfate-agarose gel electrophoresis that indicated the virtual absence of Tg. The Tg messenger ribonucleic acids (mRNAs) from controls and HSN thyroid tissue were first reverse transcribed and then divided into several portions from positions 57-8448; the resulting complementary DNAs were, in turn, amplified by reverse polymerase chain reaction. The amplification of nucleotides 5165-6048 from control thyroid tissue Tg mRNA showed a fragment of 884 base pairs (bp). In contrast, the fragment present in the HSN was +/- 750 bp and lacked the normal fragment. The sequencing of the smaller fragment revealed that 138 bp were missing between positions 5590-5727 of the HSN Tg mRNA. This deletion does not affect the reading frame of the resulting mRNA and is potentially fully translatable into a Tg polypeptide chain that is shorter by 46 residues. A cysteine residue is maintained by the junction between the proximal T from leucine 1831 and the distal GT from cysteine 1877. DNA genomic polymerase chain reaction amplification excludes a deletion in the Tg gene and indicates that the deleted 138-nucleotide sequences lie in the same exon. The functional consequences of the deletion are not entirely clear, but it is conceivable that the excision of this segment of the Tg molecule could affect the protein structure, resulting in its premature degradation, very low colloid storage, and diminished thyroid hormone production rate.

Low levels of thyroglobulin messenger ribonucleic acid in congenital goitrous hypothyroidism with defective thyroglobulin synthesis.

We characterized the virtual absence of immunoassayable thyroglobulin (Tg) in the serum and thyroid gland of two siblings (MA, JNA) and one nephew (RSS) from a family without inbreeding or familial goiter. Diagnosis of defective Tg gene expression was based on findings of normal PBI and low serum T4, low or normal serum T3, negative perchlorate discharge test, and virtual absence of the serum Tg response to challenge by bovine TSH. This conclusion was confirmed by analysis of proteins in the goiter extracts. Only minute amounts of immunoassayable Tg were detected by RIA (MA, 0.11; JNA, 0.19 mg/g tissue; compared to 70-90 mg/g in normal thyroid tissue). Gel filtration in Sephacryl S300 showed the absence of a normal Tg peak at 280 nm and concentration of label mostly on albumin. A minor intermediate peak of radioactivity was also detected, with the size of, approximately, normal Tg. Sodium dodecyl sulfate-agarose gel electrophoresis indicated the absence of Tg dimer and monomer, and Western blotting and immunoelectrophoresis confirmed this finding. Dot blot quantification of Tg and thyroid peroxidase mRNA indicated decreased hybridization of the patients' mRNA (MA, 44%; JNA, 63%) with phTgM2 (Tg probe) and increased hybridization (MA, 191%; JNA, 182%) with the pM5 (thyroid peroxidase probe) compared with control thyroid tissue. Dot blot analysis of Tg mRNA from the two siblings weakly hybridized with 3' and 5' Tg probes. RNA analysis by means of Northern transfer showed a clear signal of hybridization with Tg probe (phTgM1) in the 8- to 9-kilobase range, corresponding to the normal size Tg mRNA. No major polymorphisms were noted in Southern blotting, using seven restriction endonucleases. We conclude that no gross alteration of the 5' region of Tg gene was present in these patients. Ultrastructural examination of the thyroid tissue indicated that the rough endoplasmic reticulum was not augmented, nor were the cisternae of rough endoplasmic reticulum dilated. The defect observed in these goiters is diminished tissue concentration of Tg mRNA with defective translation. However, small amounts of functionally active Tg could be synthesized, iodinated, and immediately hydrolized, yielding mostly T3, owing to the intense tissue stimulation by TSH.

Protective effects of zinc in indomethacin-induced gastric mucosal injury: evidence for a dual mechanism involving lipid peroxidation and nitric oxide.

BACKGROUND: Indomethacin causes gastric mucosal injury, although the pathogenesis is not fully understood. Zinc, is known to have gastroprotective effects in both humans and experimental animals. AIM: To determine (i) the protective effects of zinc in indomethacin-induced gastric mucosal injury in rats, and (ii) whether these cytoprotective effects are mediated by changes in gastric lipid peroxidation and/or nitric oxide synthase activity. METHODS: Gastric lesions were induced in rats by the intragastric administration of indomethacin. Morphological changes, lipid peroxidation (malondialdehyde levels) and nitric oxide synthase activity were determined in animals pre-treated with zinc sulphate and in controls. RESULTS: Indomethacin significantly increased malondialdehyde levels and decreased NOS activity. These effects were attenuated by pre-treatment with zinc (P < 0.005 and 0.0001, respectively). The protective effects of zinc were readily abolished in animals pre-treated with N-nitro-L-arginine methyl ester (L-NAME). Morphologically, indomethacin induced large areas of mucosal ulcerations, which were completely prevented by zinc pre-treatment. CONCLUSIONS: Zinc provides protection against indomethacin-induced gastric mucosal injury. These protective effects result from the inhibition of lipid peroxidation and the preservation of mucosal nitric oxide synthase.

Normal thyroglobulin and thyroperoxidase gene expression in thyroid congenital defective thyroglobulin synthesis.

We have studied a member (JBM) of a family MO previously described, with congenital goiter, hypothyroidism, and presence of hyposialylated Tg in the follicular lumen. Other congenital goiters (MA and JNA) with virtual absence of Tg were studied similarly. The presence of apparently normal-sized Tg in JBM tissue was confirmed in the present study by radioimmunoassay, Sephacryl S300 column chromatography, immunoelectrophoresis, and SDS agarose gel electrophoresis. Dot blot hybridization analysis with Tg and TPO probes indicated that mRNA hybridization levels of JBM tissue were similar to control thyroid tissues. Congenital goiter tissues showed relatively lower TSH receptor mRNA content in comparison with normal thyroid tissues. DNA was digested with five restriction endonucleases (Taq I, Eco Rv, Pvu II, Pst I, and Eco RI), and the results revealed polymorphisms previously described with the Tg gene. No significant differences in the TPO Pst I pattern were observed in comparison with control samples. We conclude that no major alterations of the Tg and TPO gene expression are detectable and that no significant deletions of these genes are present. The biochemical abnormality in the JBM Tg molecule may be a posttranslational error during the assembly of the protein.

Intratumoral DNA content heterogeneity in laryngeal squamous cell carcinoma.

Multiple tissue samples obtained from sections cut by Michaels and Gregor's method obtained from 21 consecutive total laryngectomies for squamous cell carcinoma were studied for intratumoral DNA content heterogeneity or homogeneity. Concordant DNA ploidy was manifested in all samples of five (23.8%) carcinomas (two diploid and three aneuploid), while 16 carcinomas (76.2%) demonstrated a variable DNA ploidy (diploid and aneuploid). Analysis of cellular proliferative activity demonstrated remarkable intratumoral stability in both concordant and discordant carcinomas. These data indicate there is a considerable heterogeneity of DNA ploidy but the proliferative rate is relatively stable within the carcinomas. Clinical implications of our findings are also presented.

Molecular genetics of hereditary thyroid diseases due to a defect in the thyroglobulin or thyroperoxidase synthesis.

1. Hereditary goiter and the various degrees of thyroid hypofunction are the result of structural changes in the thyroglobulin (Tg) or thyroperoxidase (TPO) proteins, the inability to couple iodotyrosines or defective iodination, impairing or substantially altering the synthesis of T4 and T3. 2. The first mutations in the Tg and TPO genes responsible for human cases of dyshormonogenesis have been described. The mutation in two siblings with hereditary goiter and marked impairment of Tg synthesis was a cytosine to thymine transition creating a stop codon at position 1510. The point mutation is removed by the preferential accumulation of a 171-nt deleted Tg mRNA. In another subject, molecular studies revealed that exon 4 was missing from the major Tg transcript due to a cytosine to guanine transversion at position minus 3 in the acceptor splice site of intron 3. 3. Genomic DNA studies identified a duplication of a 4-base sequence in the eighth exon of the TPO gene. Interestingly, besides abolishing the enzymatic activity by disrupting the reading frame of the messenger RNA and introducing stop codons, the GGCC duplication also unmasks a cryptic acceptor splice site in exon 9. 4. In conclusion, the identification of different molecular defects provided evidence that hereditary goiter associated with abnormal Tg or TPO synthesis is caused by heterogeneous genetic alterations.

[Myocardial revascularization surgery without extracorporeal circulation]. / Cirugía de revascularización miocárdica sin circulación extracorpórea.

The number of patients who need coronary artery surgery growth every year. Most of these surgical operations are with extracorporeal circulation (ECC). Recently in our hospital this surgery is realized without ECC in selected patients. Some studies shows that this surgery is an alternative in the treatment of coronary artery disease, especially for aged patients with associated disease and in Jehovah's witness faith. A coronary artery diameter at the anastomotic site of 2 mm or greater and satisfactory hemodynamics with the cardiac manipulation are needed to realize this surgery. Given these limitations this technique has proved useful in selected patients requiring revascularization of the left anterior descending, circumflex or right coronary artery (not for grafting the posterior descending branch). The need of mechanical ventilation, days at ICU, blood required, morbidity and mortality, in our experience as in other studies, were fewer than surgery with CEC.

Estado de salud y autoeficacia en adultos mayores usuarios de atención primaria en salud / Health status and self -efficacy in elderly users in primary care

RESUMEN Objetivo: Identificar el nivel de autoeficacia percibida y su relación con variables biodemográficas y psicosociales en adultos mayores. Material y método: Diseño descriptivo correlacional, muestreo aleatorio estratificado, de 754 adultos mayores inscritos en centros de salud de Antofagasta, Chile. Mediciones: antecedentes socio-demográficos, estado de salud, autoeficacia percibida; Examen de Funcionalidad del Adulto Mayor (parte B); Calidad de vida relacionada con la salud, medida con el Cuestionario SF-12 y Fragilidad. Resultados: 61,4% de mujeres versus 38,6% de hombres; la edad osciló entre los 65 y 90 años, con una media de 73 años (DE= 6,0); el 78,9% declaró de dos a seis años de estudios. Los antecedentes mórbidos presentados con mayor frecuencia fueron: Hipertensión arterial, Dislipidemia y Diabetes Mellitus. El 86,3% no presentó depresión. La autopercepción de salud calificada como "excelente a buena" alcanzó sobre el 60%. La autoeficacia fue percibida alta en un 68,3%. La calidad de vida relacionada con salud global fue percibida con satisfacción por el 55,6%. Los niveles de fragilidad alcanzaron el 73,5%. El 59,3% de los adultos mayores fueron clasificados como autovalente sin riesgo. Se encontraron diferencias estadísticamente significativas entre las categorías de autoeficacia y temor a caerse, estado nutricional, depresión, calidad de vida relacionada con salud y la autopercepción de salud. Conclusión: Se identificó y relacionó una alta autoeficacia percibida, tanto en variables biodemográficas como psicosociales, que podría ser un factor facilitador para promover un envejecimiento activo.

ABSTRACT Objective: Identify the level of perceived self-efficacy and its relationship with biodemographic and psychosocial variables in older adults. Material and method: Descriptive correlational design, stratified random sampling, of 754 older adults registered in health centers of Antofagasta, Chile. Measurements : sociodemographic background, health status, perceived self-efficacy; Functional Test of the Elderly (part B); Quality of life related to health, measured with the SF-12 and Fragility Questionnaire. Results: 61.4% of participants were women and 38.6% were men; the ages ranged between 65 and 90 years, with an average of 73 years (SD = 6.0); 78.9% declared between two and six years of schooling. The morbid antecedents most frequently presented were: Arterial Hypertension, Dyslipidemia and Diabetes Mellitus. 86.3% did not present depression. Self-rated health rated "excellent to good" reached over 60%. Self-efficacy was perceived as high by 68.3% of participants. A 55.6% was satisfied with their quality of life in relation to global health. Fragility levels reached 73.5%. 59.3% of older adults were classified as self-reliant without risk. Statistically significant differences were found between the categories of self-efficacy and fear of falling, nutritional status, depression, quality of life related to health and self-perception of health. Conclusion: A high perceived self-efficacy was identified and related, both in biodemographic and psychosocial variables, which could be a facilitating factor to promote active aging.

Indicadores de fragilidad en adultos mayores del sistema público de salud de la ciudad de Antofagasta / Rates of frailty among older people ascribed to chilean primary care clinics

Background: Frailty is not universal among older people but increases the risk of dependence. Aim: To assess frailty among older people and its relationship with biological, psychological and social factors. Material and Methods: Seven hundred fifty four older people aged 73 ± 6 years (61% females), attending a public primary care were assessed. Frailty was defined according to Fried criteria that considers inexplicable weight loss, tiredness, muscle weakness and lack of physical activity. Results: Absence of frailty, pre-frailty and frailty was found in 26, 69 and 5% of participants, respectively. Significant differences between frailty groups were observed for age, gender, years of studies, minimental and self-efficacy scores. Among participants defined as being in a pre-frail condition, 59% were non-disabled without risk and 41% non-disabled in risk, according to the functional assessment for older people used in Chilean primary care clinics. Conclusions: Frailty among older people is associated with increasing age, education, cognitive status and self-efficacy.

[Cross sectional geriatric assessment of free living older subjects from Antofagasta, Chile]. / Valoración multidimensional del envejecimiento en la ciudad de Antofagasta.

BACKGROUND: The effects of aging on people must be evaluated to adequate sanitary actions. AIM: To assess the characteristics of older subjects living in Antofagasta, Chile. MATERIAL AND METHODS: Cross sectional assessment of 602 subjects without dementia, aged more than 60 years (55% females). A socioeconomic and medical history was obtained and Barthel, Lawton, Yesavage depression, Tromp fall risk and Folstein Mini mental scales were applied. RESULTS: Sixty eight percent of subjects had more than six years of studies. Forty six percent had hypertension, 28% had osteoarticular problems, 20% had hypercholesterolemia and 17% diabetes mellitus. Four percent had depression and falls were reported by 35%. Seventy four percent were independent in basic and instrumental activities. Ninety four percent had normal cognitive functions. Age was an important determinant of functional capacity. CONCLUSIONS: The main problems detected in this sample were the risk of falls and the presence of chronic diseases.

Effect of different nitrogen sources on plant characteristics and yield of common bean (Phaseolus vulgaris L.).

Wastewater sludge can be used to fertilize crops, especially after vermicomposting (composting with earthworms to reduce pathogens). How wastewater sludge or vermicompost affects bean (Phaseolus vulgaris L.) growth is still largely unknown. In this study the effect of different forms of N fertilizer on common bean plant characteristics and yield were investigated in a Typic Fragiudepts (sandy loam) soil under greenhouse conditions. Beans were fertilized with wastewater sludge, or wastewater sludge vermicompost, or urea, or grown in unamended soil, while plant characteristics and yield were monitored (the unamended soil had no fertilization). Yields of common bean plants cultivated in unamended soil or soil amended with urea were lower than those cultivated in wastewater sludge-amended soil. Application of vermicompost further improved plant development and increased yield compared with beans cultivated in wastewater amended soil. It was found that application of organic waste products improved growth and yield of bean plants compared to those amended with inorganic fertilizer.

Emission of CO2 and N2O from soil cultivated with common bean (Phaseolus vulgaris L.) fertilized with different N sources.

Addition of different forms of nitrogen fertilizer to cultivated soil is known to affect carbon dioxide (CO(2)) and nitrous oxide (N(2)O) emissions. In this study, the effect of urea, wastewater sludge and vermicompost on emissions of CO(2) and N(2)O in soil cultivated with bean was investigated. Beans were cultivated in the greenhouse in three consecutive experiments, fertilized with or without wastewater sludge at two application rates (33 and 55 Mg fresh wastewater sludge ha(-1), i.e. 48 and 80 kg N ha(-1) considering a N mineralization rate of 40%), vermicompost derived from the wastewater sludge (212 Mg ha(-1), i.e. 80 kg N ha(-1)) or urea (170 kg ha(-1), i.e. 80 kg N ha(-1)), while pH, electrolytic conductivity (EC), inorganic nitrogen and CO(2) and N(2)O emissions were monitored. Vermicompost added to soil increased EC at onset of the experiment, but thereafter values were similar to the other treatments. Most of the NO(3)(-) was taken up by the plants, although some was leached from the upper to the lower soil layer. CO(2) emission was 375 C kg ha(-1) y(-1) in the unamended soil, 340 kg C ha(-1) y(-1) in the urea-amended soil and 839 kg ha(-1) y(-1) in the vermicompost-amended soil. N(2)O emission was 2.92 kg N ha(-1) y(-1) in soil amended with 55 Mg wastewater sludge ha(-1), but only 0.03 kg N ha(-1) y(-1) in the unamended soil. The emission of CO(2) was affected by the phenological stage of the plant while organic fertilizer increased the CO(2) and N(2)O emission, and the yield per plant. Environmental and economic implications must to be considered to decide how many, how often and what kind of organic fertilizer could be used to increase yields, while limiting soil deterioration and greenhouse gas emissions.

Valoración multidimensional del envejecimiento en la ciudad de Antofagasta / Cross sectional geriatric assessment of free living older subjects from Antofagasta, Chile

Background: The effects of aging on people must be evaluated to adequate sanitary actions. Aim: To assess the characteristics of older subjects living in Antofagasta, Chile. Material and Methods: Cross sectional assessment of 602 subjects without dementia, aged more than 60 years (55 percent females). A socioeconomic and medical history was obtained and Barthel, Lawton, Yesavage depression, Tromp fall risk and Folstein Mini mental scales were applied. Results: Sixty eight percent of subjects had more than six years of studies. Forty six percent had hypertension, 28 percent had osteoarticular problems, 20 percent had hypercholesterolemia and 17 percent diabetes mellitus. Four percent had depression and falls were reported by 35 percent. Seventy four percent were independent in basic and instrumental activities. Ninety four percent had normal cognitive functions. Age was an important determinant of functional capacity. Conclusions: The main problems detected in this sample were the risk of falls and the presence of chronic diseases.

Modifications of the pituitary-thyroid axis induced by hypobaric hypoxia.

The effects of simulated altitude induced by a decompression chamber upon the blood levels of thyrotropin (TSH), thyroxine (T4) and triiodothyronine (T3), measured by radioimmunoassay, were studied in male Wistar rats. When blood was extracted during the first 15 minutes after the rats were removed from the chamber and analysed, it was found that TSH levels decreased at 380 mmHg during 24 hours and sometimes at 440 mmHg during 24 hours, but this did not happen when the exposure lasted a week. Likewise, serum levels of T4 and T3 decreased at 440 mmHg during 24 hours, but they did not decrease using the same exposure during a week. When the blood was extracted 1 hour after the rats were removed from the chamber and analysed, TSH levels markedly increased at 380 mmHg and at 440 mmHg, during 1 day and during a week. Serum T4 and T3 levels were found to be normal. These results show that severe hypobaric hypoxia is needed in order to depress serum TSH levels. When the rats are removed from the decompression chamber, however, a rebound effect with marked increase in serum TSH levels can be seen before 1 hour elapses.