[Association between major depression and arterial hypertension in a Colombian population]. / Asociación entre depresión mayor e hipertensión arterial en una población colombiana.

INTRODUCTION: A third of hypertensive patients have major depression, a relationship that is associated with a worse prognosis. The objective of the study was to estimate the association between depression and high blood pressure, as well as to establish the possible bidirectionality of the conditions. MATERIALS AND METHODS: Retrospective cohort study. People between 18 and 65 years old with high blood pressure, depression or use of medications for their management were included. To analyze the antecedent, a comorbidity model was performed. A bivariate analysis was performed and then a multivariate logistic regression. The association was estimated using the Chi-square test and the odds ratios that were crude and adjusted to the other variables included in the analysis. The Hosmer-Lemeshow test was used to assess the goodness of fit. SPSS® v.21 was used as the statistical package. RESULTS: A total of 1,721 people were included in the study. The prevalence of depression in patients with and without hypertension was 17.4 and 12.6%, respectively, with a 43% risk of hypertension in people with depression. In patients with depression, it preceded the diagnosis of hypertension in 64.8% of cases and in hypertensive patients, 22.2% were later diagnosed with depression. The association between high blood pressure and major depression remained significant after adjusting for the other risk factors. CONCLUSIONS: Depression was found as a risk factor for high blood pressure, with a 2-way risk relationship between depression and high blood pressure.

Adaptive changes in thyroid function of female rats fed a high-fat and low-protein diet during gestation and lactation.

The percent of lipids in the western diet has been continuously increasing in the last decades and is associated with a decrease in the proportion of protein intake. Recently, we demonstrated that protein malnutrition during lactation is associated with lower body weight and thyroid hypofunction in female rats and their offspring. Our objective in the present study was to determine if a high-fat and low-protein diet was associated with similar changes. Three-month-old female Wistar rats were randomly assigned to one of the following groups with 8 animals each: high-fat and low-protein (40% lipid, 5% protein, and 55% carbohydrate of the total energy content) from the 3rd week of gestation to the end of lactation; control group--standard diet (11% lipid, 23% protein, and 66% carbohydrate of the total energy content). Food consumption and body weight were monitored daily. Serum thyrotropin and thyroid hormone concentrations were determined by specific radioimmunoassay at the end of lactation. Animals receiving high-fat and low-protein diet had a significantly lower body weight (13.9% at weaning, P < 0.05) and serum albumin (25%, P < 0.05) and thyrotropin (26.2%, P < 0.01) concentrations, and a higher serum triiodothyronine concentration (74%, P < 0.005) and 131I-thyroid uptake (77%, P < 0.005). These data show that a high-fat and low-protein diet can promote maternal thyroid hyperfunction that differs from the thyroid hypofunction observed in dams fed a low-protein diet, a phenomenon that can be of adaptive importance for pup nurturing.

Adaptive changes in thyroid function of female rats fed a high-fat and low-protein diet during gestation and lactation

The percent of lipids in the western diet has been continuously increasing in the last decades and is associated with a decrease in the proportion of protein intake. Recently, we demonstrated that protein malnutrition during lactation is associated with lower body weight and thyroid hypofunction in female rats and their offspring. Our objective in the present study was to determine if a high-fat and low-protein diet was associated with similar changes. Three-month-old female Wistar rats were randomly assigned to one of the following groups with 8 animals each: high-fat and low-protein (40% lipid, 5% protein, and 55% carbohydrate of the total energy content) from the 3rd week of gestation to the end of lactation; control group - standard diet (11% lipid, 23% protein, and 66% carbohydrate of the total energy content). Food consumption and body weight were monitored daily. Serum thyrotropin and thyroid hormone concentrations were determined by specific radioimmunoassay at the end of lactation. Animals receiving high-fat and low-protein diet had a significantly lower body weight (13.9% at weaning, P < 0.05) and serum albumin (25%, P < 0.05) and thyrotropin (26.2%, P < 0.01) concentrations, and a higher serum triiodothyronine concentration (74%, P < 0.005) and 131I-thyroid uptake (77%, P < 0.005). These data show that a high-fat and low-protein diet can promote maternal thyroid hyperfunction that differs from the thyroid hypofunction observed in dams fed a low-protein diet, a phenomenon that can be of adaptive importance for pup nurturing.

Genetic variation and relationships at six VNTR loci in two distinct sample populations in Brazil.

BACKGROUND: The Brazilian population has been the focus of intensive genetic study due to admixture characteristics whereas there are few reports on the variability of VNTR loci in Brazil. PRIMARY OBJECTIVE: The aim of this study was to analyse genetic parameters in sample populations from two geographically distant regions: São Luis City, in Maranhão State and Campinas City, in São Paulo State. We investigated if distinct colonization influences could produce detectable differences in genetic background. SUBJECT AND METHODS: DNA samples from peripheral drained blood were obtained from unrelated individuals who underwent paternity testing. Allelic variation in six VNTR loci (D2S44, D4S139, D5S110, D8S358, DI0S28 and D17S79) was evaluated. The results were compared to reference databases available for general Latin-derived European and African-American populations as well as for other Brazilian groups. RESULTS: This study reveals that forensic population parameters did not show differences among regions, although we detected admixture values varying between the south-east and north-east of Brazil. CONCLUSIONS: Differences between the two samples are probably due to different admixture proportions of European- and African-derived alleles in each region: both populations are in Hardy Weinberg equilibrium. In addition, the allelic frequency for all loci, in both populations, can be used as database for forensic purposes.

Necrobiotic xanthogranuloma with lambda paraproteinemia: case report of successful treatment with melphalan and prednisone.

BACKGROUND: Necrobiotic xanthogranuloma (NXG) is a rare non-X histiocytosis with conspicuous lesions on the periorbital skin. METHODS: A diabetic patient presented with NXG and a previous diagnosis of necrobiosis lipoidica on the legs over a period of almost 2 years before the development of the typical lesions of NXG on the periorbital regions, back, thighs and legs. The patient was found also to have developed lambda paraproteinemia. RESULTS: Treatment with melphalan and prednisone resulted in great improvement of cutaneous lesions and paraproteinemia remission. CONCLUSION: This case report details how melphalan and prednisone can be administered in the successful treatment of necrobiotic xanthogranuloma with lambda paraproteinemia.

Antithrombin deficiency in Brazilian patients with venous thrombosis: molecular characterization of a single splice site mutation, an insertion and a de novo point mutation.

The prevalence of antithrombin (AT) deficiency in 342 unselected Brazilian patients with venous thrombosis was 1.16%, which increased to 3% when only patients under the age of 50 or with a familial history of thrombosis were considered. In two patients, a clinical (contraceptive use) or genetic risk factor (factor V Leiden and C677T in the methylene tetrahydrofolate reductase gene [MTHFR]) was identified and corroborated the hypothesis that an interaction of factors accounted for the appearance of thrombosis. However, no risk factor other than AT deficiency was identified in one patient with an important clinical and family history of spontaneous thrombosis. Three mutations were identified in these patients: a G-->A transition in intron 5 at position +1 (5'-->3'), three base insertions corresponding to arginine at position 5383 in exon 3A, and a G-->A transition at 13328, corresponding to an Ala404Thr de novo mutation. The polymorphisms in the genes coding for coagulation factors XII and XIII and fibrinogen normally associated with an increased risk for venous thrombosis were not related to thrombosis in these patients. This is the first study in South America to assess the prevalence of AT deficiency and to report the molecular characterization of the mutations involved.

Low-protein diet changes thyroid function in lactating rats.

Lactating rats were fed with free access to an 8% protein-restricted diet (PR); the control group was fed a 23% protein diet (C). An energy-restricted (pair-fed) group was given the same food as the animals in the control group, but the amounts of food consumed by both PF and PR were about the same. The body weight and serum albumin concentration of PR and PF dams were significantly (P < 0. 05) lower than that of the controls. The PR group had a significant increase in serum-free triiodothyronine (FT3) concentration, 24-hr mammary gland and milk radioiodine (I131) uptake (67%, 278%, and 200%, respectively) as compared with the controls. On the other hand, those animals had a significantly lower serum-free thyroxine (FT4) concentration and 2- and 24-hr thyroid I131 uptake (67%, 64%, and 74%, respectively). Protein malnutrition during lactation did not alter thyroid or liver 5'-deiodinase activity significantly. However, PF dams had a significantly lower (25%) thyroid 5'-deiodinase activity. These data suggest that protein-restricted lactating dams had an adaptive change in the thyroid function, which could be important to increase the transference of iodine or triiodothyronine through the milk to their pups and prevent sequelae of neonatal hypothyroidism.

The effect of protein or energy restriction on the biodistribution of Na99TcmO4 in Wistar rats.

The effect of malnutrition on the biodistribution of radiopharmaceuticals is not known. We studied the biodistribution of 99Tcm-labelled sodium pertechnetate (Na99TcmO4) in two rat models of malnutrition. Three groups of 2-month-old rats were separated according to their diets: (1) control diet, 23% protein (C); (2) protein-restricted, receiving 8% protein (PR), both ad libitum; and (3) energy-restricted, receiving 60% of control diet (ER). After 21 days of the diet, 99Tcm was injected and the animals were killed after 30 min. The organs were isolated, their weight determined and the absolute per cent (%ID) and the per cent per gram injected dose (%ID x g(-1)) calculated. The %ID and %ID x g(-1) had a similar pattern, increasing in stomach and brain and decreasing in the thyroid, but did not change significantly in kidney, lung, liver, bone or testis in PR rats, except in the heart where the increase was only observed in the %ID x g(-1). In the ER group the %ID x g(-1) was decreased in the bone only, and did not change in the other organs. It is suggested that when using Na99TcmO4 scintigraphy in malnourished patients, the different patterns of distribution must be kept in mind.

Combination therapy with amphotericin B and fluconazole against invasive candidiasis in neutropenic-mouse and infective-endocarditis rabbit models.

Although there are an increasing number of new antifungal agents available, the morbidity and mortality due to invasive mycoses remain high. The high rates of polyene toxicities and the development of azole resistance have raised the issue of using antifungal agents of these classes in combination, despite theoretical concerns regarding antagonism between such agents. This study was designed to evaluate the in vivo efficacy of combined therapy with amphotericin B and fluconazole against Candida albicans. Two distinct animal models were used in this study: a neutropenic-mouse model of hematogenously disseminated candidiasis and the infective-endocarditis rabbit model. Treatment efficacy was assessed by determining reductions in mortality as well as decreases in tissue fungal densities. In the neutropenic-mouse model, amphotericin B, as well as combination therapy, significantly prolonged survival compared to untreated controls (P < 10(-5) and P = 0.001, respectively). The fungal densities in the kidneys of neutropenic mice were significantly reduced with either amphotericin B monotherapy or amphotericin B-fluconazole combined therapy compared to those of controls (P < 10(-6)). Fluconazole monotherapy also reduced fungal densities in the kidneys; however, this decrease was not statistically significant (P = 0.17). In contrast, treatment with either fluconazole alone or combined with amphotericin B (but not amphotericin B monotherapy) significantly decreased fungal densities in the brain (P = 0.025). In the rabbit endocarditis model, amphotericin B monotherapy or combined therapy significantly decreased fungal densities in cardiac vegetations (P < 0.01 versus the controls). Although no significant antagonism was seen when fluconazole was given in combination with amphotericin B, combination therapy did not augment the antifungal activity of amphotericin B.

Thyroid function in post-weaning rats whose dams were fed a low-protein diet during suckling.

This study was designed to evaluate the thyroid and pituitary hormone levels in post-weaning rats whose dams were fed a low-protein diet during suckling (21 days). The dams and pups were divided into 2 groups: a control group fed a diet containing 22% protein that supplies the necessary amount of protein for the rat and is the usual content of protein in most commercial rat chow, and a diet group fed with a low-protein (8%) diet in which the protein was substituted by an isocaloric amount of starch. After weaning all dams and pups received the 22% protein diet. Two hours before sacrifice of pups aged 21, 30 and 60 days, a tracer dose (0.6 microCi) of 125I was injected (i.p.) into each animal. Blood and thyroid glands of pups were collected for the determination of serum T4, T3 and TSH and radioiodine uptake. Low protein diet caused a slight decrease in radioiodine uptake at 21 days, and a significant decrease in T3 levels (128 +/- 14 vs 74 +/- 9 ng/dl, P < 0.05), while T4 levels did not change and TSH was increased slightly. At 30 days, T3 and TSH did not change while there was a significant increase in both T4 levels (4.8 +/- 0.3 vs 6.1 +/- 0.2 micrograms/dl, P < 0.05) and in radioiodine uptake levels (0.34 +/- 0.02 vs 0.50 +/- 0.03%/mg thyroid, P < 0.05). At 60 days serum T3, T4 and TSH levels were normal, but radioiodine uptake was still significantly increased (0.33 +/- 0.02 vs 0.41 +/- 0.03%/mg thyroid, P < 0.05). Thus, it seems that protein malnutrition of the dams during suckling causes hypothyroidism in the pups at 21 days that has a compensatory mechanism increasing thyroid function after refeeding with a 22% protein diet. The radioiodine uptake still remained altered at 60 days, when all the hormonal serum levels returned to the normal values, suggesting a permanent change in the thyroid function.

Thyroid function in post-weaning rats whose dams were fed a low-protein diet during suckling

This study was designed to evaluate the thyroid and pituitary hormone levels in post-weaning rats whose dams were fed a low-protein diet during suckling (21 days). The dams and pups were divided into 2 groups:a control group fed a diet containing 22 per cent protein that supplies the necessary amount of protein for the rat and is the usual content of protein in most commercial rat chow, and a diet group fed a lowprotein (8 per cent) diet in which the protein was substituted by an isocaloric amount of starch. After weaning all dams and pups received the 22 per cent protein diet. Two hours before sacrifice of pups aged 21, 30 and 60 days, a tracer dose (0.6 mui) ofl25I was injected (ip) into each animal. Blood and thyroid glands of pups were collected for the determination of serum T4, T3 and TSH and radioiodine uptake. Low protein diet caused a slight decrease in radioiodine uptake at 21 days, and a significant decrease in T3 levels (l28 ñ 14 vs 74 ñ 9 ng/dl, P<0.05), while T4 levels did not change and TSH was increased slightly. At 30 days, T3 and TSH did not change while there was a significant increase in both T4 levels (4.8 ñ 0.3 vs 6.1 ñ 0.2 mug/dl, P<0.05) and in radioiodine uptake levels (0.34 ñ 0.02 vs 0.50 ñ 0.030 per cent/mg thyroid, P<0.05). At 60 days serum T3, T4 and TSH levels were normal, but radioiodine uptake was still significantly increased (0.33 ñ 0.02 vs 0.41 ñ 0.03 per cent/mg thyroid, P<0.05). Thus, it seems that protein malnutrition of the dams during suckling causes hypothyroidism in the pups at 21 days that has a compensatory mechanism increasing thyroid function after refeeding with a 22 per cent protein diet. The radioiodine uptake still remained altered at 60 days, when all the hormonal serum levels returned to the normal values, suggesting a permanent change in the thyroid function.

Parameter identification of a neurological control model for the pathological head movements of cerebellar patients.

The objective of this research is to explore the role of the cerebellum in the human motor control system. The present study quantitatively compares the neurological control signals effecting fast, horizontal head rotations in normal subjects to those in patients with a cerebellar lesion. The method involves the use of a computer simulation model for one degree-of-freedom movements. A method for unconstrained global optimization, first proposed by Hans Bremermann (1970), is used to identify the timing and magnitudes of the input neurological control signals to the model, which are compared to recorded electromyograms (EMGs). Experimentally recorded kinematics from cerebellar patients and from normal subjects were used to drive the parameter search. These simulations found that cerebellar patients' neurological control signals were altered with respect to those of normal subjects, and suggest that the electromyographic activity of cerebellar patients may comprise at least five bursts of activity whereas normal subjects typically exhibit only three. The results are discussed with respect to the hypothesis that the cerebellum may be involved in both the timing and magnitudes of the neurological control signals effecting voluntary movement.

Two cases of Y; autosome translocations: A 45,X male and a clinically trisomy 18 patient.

We report on 2 cases of Y; autosome translocations. One is a male with normal external genitalia and 45,X karyotype without evidence of mosaicism or apparent translocation on cytogenetic analysis. In situ hybridization showed that the euchromatic portion of the Y-chromosome is translocated to the chromosome 15. The other case is a clinically trisomy 18 male patient, with modal number of 46, a small metacentric marker with appearance of an i(18p) and cytogenetic and molecular evidence of Y;18 translocation. The occurrence of Y;18 translocation associated with clinical signs of trisomy 18 is reported here for the first time.

Geometrical approach to neural net control of movements and posture.

In one approach to modeling brain function, sensorimotor integration is described as geometrical mapping among coordinates of non-orthogonal frames that are intrinsic to the system; in such a case sensors represent (covariant) afferents and motor effectors represent (contravariant) motor efferents. The neuronal networks that perform such a function are viewed as general tensor transformations among different expressions and metric tensors determining the geometry of neural functional spaces. Although the non-orthogonality of a coordinate system does not impose a specific geometry on the space, this "Tensor Network Theory of brain function" allows for the possibility that the geometry is non-Euclidean. It is suggested that investigation of the non-Euclidean nature of the geometry is the key to understanding brain function and to interpreting neuronal network function. This paper outlines three contemporary applications of such a theoretical modeling approach. The first is the analysis and interpretation of multi-electrode recordings. The internal geometries of neural networks controlling external behavior of the skeletomuscle system is experimentally determinable using such multi-unit recordings. The second application of this geometrical approach to brain theory is modeling the control of posture and movement. A preliminary simulation study has been conducted with the aim of understanding the control of balance in a standing human. The model appears to unify postural control strategies that have previously been considered to be independent of each other. Third, this paper emphasizes the importance of the geometrical approach for the design and fabrication of neurocomputers that could be used in functional neuromuscular stimulation (FNS) for replacing lost motor control.

Use of Y-chromosome-specific DNA probes to evaluate an XX male.

1. The function of a Y human chromosomal DNA sequence was evaluated. The Y-5 probe was isolated from a flow-sorted chromosome library and detects Y-specific sequences. 2. The Y-5 probe and other Y-specific probes were used to analyze an XX male patient without ambiguous genitalia. 3. DNA sequences from the short arm of the chromosome Y that were detected with pDP1007 and pDP105 in the patient's genome explain the testis differentiation observed in this case. 4. Failure of the patient's DNA to hybridize to the Y-5 probe shows that the primitive gonads can differentiate into testes even in the absence of this chromosome region. In contrast, a gene controlling spermatogenesis may exist in this region because the patient is azoospermic.

Use of y-chromosome-specific DNA probes to evaluate an XX male

The function of a Y human chromosomal DNA sequence was evaluated. The Y-5 probe was isolated from a flow-sorted chromosome library and detects Y-specific sequences. The Y-5 probe and other T-specific probes were used to analyze an XX male patient without ambiguous genitalia. DNA sequences from the short arm of the chromosome Y that were detected with pDP1007 and DP105 in the patient's genome explain the testis differentation observed in this case. Failure of the patient's DNA to hybridize to the Y-5 probe shows that the primitive gonads can differentiate into testes even in the absence of this chromosome region. In contrast, a gene controlling spermatogenesis may exist in this region because the patient azoospermic

Behaviour space of a stretch reflex model and its implications for the neural control of voluntary movement.

A nonlinear model for the stretch reflex has recently been used to study the interactions between voluntary and reflex controls during fast, targeted movements. The present study explores the topography of a 'behaviour space' generated by computer simulations of this model under various combinations of values for the gain parameters and time constants in the model's feedback loops. In general, we define a behaviour space to be any set of behavioural characteristics of the simulated movement, such as movement time, peak acceleration or peak velocity. The mathematical model can therefore be viewed as an M x N dimensional map from its parameter space N to a behaviour space M. Here, a one-dimensional behaviour space is explored. This provides a method for quantitatively comparing the different control strategies that might be employed by the nervous system for integrating reflex and descending signals during fast, voluntary movements. The results indicate that an optimal strategy will employ proprioceptive feedback as a means of fine-tuning the braking and clamping activities of fast, goal-directed movements and that descending signals are primarily important for initiating the movement and for controlling reciprocal patterns of muscle activity during the end phase of the movement.

Postural maintenance during movement: simulations of a two joint model.

Voluntary movements of the upper body are accompanied by anticipatory postural adjustments to the lower body in a standing subject. The long-standing hypothesis is that these anticipatory adjustments serve to counteract the perturbation to the body's center of gravity caused by the voluntary arm movement. This paper presents model simulations investigating the possible roles of anticipatory postural activity that accompanies a rapid, upward arm swing. The model incorporates two (idealized) antagonistic muscle pairs controlling the movements of a double-joint system, with a "shoulder joint" between the arm and stiff body links, and an "ankle joint" between the stiff body-leg segment and the ground. Each muscle is represented by a nonlinear viscoelastic element and also includes proprioceptive feedback. Four inputs to the model define the motor control signals for muscle force generation in both the arm and the postural muscle pairs. The neurological component of the model describes consequences of alternate strategies for cocontractions, stretch reflex activity, and anticipatory and synchronous postural activities (or combinations thereof). Simulations with this model show that: (1) none of the postural maintenance schemes considered in these simulations (including varying anticipation) could suppress the initial backward thrust on the body link; (2) the more important destabilizing perturbation is a subsequent forward sway that, left uncountered by postural activity, would eventually leave the body to fall flat on its face; and (3) anticipatory silencing of the postural extensor followed by a brief period of extensor activation (descending control) and synchronous reflex activity (feedback control) appears to be the most likely postural stabilizing strategy that inhibits the continuous forward sway and is consistent with the experimental evidence.

Postural maintenance during fast forward bending: a model simulation experiment determines the "reduced trajectory".

A recent article by Crenna et al. (1987) has shown that fast, forward bending movements are accompanied by a backwards motion of the hips and lower limbs. The ongoing research presented in this brief note expands upon the experimental data described by Crenna and colleagues, concerning the postural activities associated with rapid forward bending in standing man. Our primary experimental tool is the computer simulation method, with the standing subject being represented by a double-joint system: the trunk is modeled as a rigid link mechanically coupled (via a "hip" joint) to the lower body link fixed to the ground (via an "ankle" joint). Each of the two joints in this system is independently controlled by a neurological control model for single joint movements, consisting of an idealized pair of antagonistic muscles (flexor and extensor), their common load, and proprioception from the muscle spindles. This model thereby integrates descending commands with proprioceptive feedback in controlling the joint movements. Our early simulation experiments determine a "reduced trajectory", that is, the physical perturbation to the postural system, due to the voluntary movement, in the absence of any stabilizing activities. These simulation experiments clearly show that an important component of the backward movements in the hips and lower limbs during forward bending is indeed due to the mechanical (physical) coupling between the upper and lower body segments and thus not solely a consequence of the anticipatory postural muscle activity. Simulations also predict that any postural activities in the hips and lower limbs should be a two-fold process: first, some preprogrammed, descending control to the lower body would be required to actively enhance the passive, backwards motion (this is consistent with, though not strictly identical to, the hypothesis of Crenna and colleagues); secondly, there must be a subsequent activation in the anterior muscles of the lower body in order to arrest this backwards motion, since otherwise the uncountered momentum would carry the body backward to the floor in less than half a second after the upper body movement has terminated.

A technical improvement for the thyroid peroxidase iodination assay.

Thyroid peroxidase (TPO) iodination activity is generally evaluated in vitro by the iodination of poorly iodinated thyroglobulin or bovine serum albumin, followed by separation of protein-bound and inorganic iodide by paper chromatography. Precipitation of protein-bound iodine by trichloroacetic acid (TCA) was evaluated as an alternative to the time-consuming paper chromatographic separation (PC) in normal rat TPO preparations. The protein-bound iodine estimates as well as the iodination activities determined by these two procedures were significantly correlated (r = 0.95 and 0.98, respectively, P less than 0.001), and the iodination activities regression line slope (b = 0.97 +/- 0.11) was not different from 1. The protein-bound iodine separation by TCA is simpler and faster, without loss of precision. Thus, it can be a useful alternative step in the thyroid peroxidase iodination assay.