Biomedical subjects

J Santander

Publications and source records attributed to J Santander.

8 recordsLinked to original sources

PubMed2004

Thermal AFM: a thermopile case study.

In this work, an atomic force microscope (AFM) with an integrated thermal sensor has been used to obtain the local spatial distribution of temperatures in a micromachined thermopile with submicron resolution. In this communication, we will show how the dimensional, structural and functional characteristics of a thermopile suits well with the requirements for AFM thermal imaging, and how a deeper insight of the thermopile operation can be gained with the aid of these advanced scanning probe-based tools.

Diagnostic Imaging↗

PubMed1998

Personality patterns and outcome in depressive and bipolar disorders.

Personality traits and disorders have a strong influence on the course and outcome of depressive and bipolar disorders. Studies of the influence of personality disorders (PD) and some PD clusters on outcome of mood disorders are controversial and suggest that more specific assessment of underlying traits or dimensions is needed. Utilizing the Munich Personality test (MP-T) scales of von Zerssen, this study tries to identify specific personality traits that may influence the outcome and clinical course of unipolar endogenous depression and bipolar disorder. Six unipolar depressives and 6 bipolar patients, according to DSM III-R and ICD 10 criteria, were assessed with the MP-T self- and family-reporting scales. Three years later, their outcome scores were correlated with the corresponding premorbid personality profile. Preliminary results show that introversion has a negative effect on outcome of unipolar melancholic depression, while extraversion, esoteric tendencies and rigidity have a positive influence. Neuroticism has a negative influence on outcome of bipolar disorder, but not on unipolar endogenous depression. Data from the literature suggest that neuroticism, hostility and social dysfunction seem to have a negative prognostic value only for nonendogenous depressives and bipolar disorder, thus supporting the notion that the diagnostic distinction between bipolar disorder, endogenous and nonendogenous depression is relevant to prognostic discussions. These observations help to understand the differences between depressive syndromes and their relationship to prognosis, but also to comprehend the role of personality in clinical and theoretical research of mood disorders.

Adult↗

PubMed1997

Complex segregation analysis of schizophrenia in Santiago, Chile.

Genetic epidemiologic studies have provided evidence that genetic factors contribute to familial aggregation of schizophrenia. However, the precise mode of inheritance has not been elucidated. The majority of such studies have been carried out in Caucasian populations. The present study was performed in Santiago, Chile, whose population stems from the admixture of Amerindians with Spaniards. The sample consisted of 44 randomly ascertained schizophrenic probands (22 males and 22 females) with ages ranging between 20 and 48 years. The diagnosis was made according to DSM-III-R criteria. Both probands and relatives were interviewed using a structured interview (CIDI) and the DSM-III-R checklist. Complex segregation analysis was carried out using the computer program POINTER. The non-transmission model (Q = H = 0) was rejected as well as the recessive single locus (H = 0, Z = 1). The multifactorial, the single codominant, the non-major locus component, the non-polygenic component transmission model and the non-transmission of a major effect could not be rejected. The model that best fits the data of the present study is that of a mixed model with a great environmental component (93.12%). The frequency of the major gene was estimated at 0.000155. Our results are similar to previous reports in ethnically different populations.

Adult↗

PubMed1996

[Tolerance of ambiguity in endogenous psychoses from the transcultural viewpoint].

This study tries to determine the relationship between intolerance of ambiguity and different psychiatric disorders classified according to DSM-III-R criteria in two different countries. Inpatients from the psychiatric department of the Universidad de Chile and the psychiatric department of the University of Heidelberg (Germany) with uniplar, bipolar or schizophrenic disorders, as well as normal controls in both cultures completed the Kischkel Intolerance of Ambiguity Scale. The group of unipolar depressive inpatients showed significantly higher scores in both samples. Among the Chilean schizophrenic patients, differences between unipolar and bipolar disorders were seen only in the Chilean sample. Differences between unipolar depressive and schizophrenic patients were evident in the German sample only. The psychopathological and nosological significance of these findings in unipolar depressives is discussed.

Adult↗

PubMed1996

[Genetic factors study in family aggregation of schizophrenia in Santiago, Chile].

BACKGROUND: Genetic epidemiological studies indicate that genetic factors contribute to a familial aggregation of schizophrenia. The form of inheritance has not been elucidated but most studies have been done in Caucasian populations. AIM: To study the form of inheritance of schizophrenia in an urban population of Santiago, Chile, containing an admixture of Spanish origin individuals with Southamerican aborigines. SUBJECTS AND METHODS: Forty four randomly selected schizophrenic probands, 22 female, aged 28 to 48 years old, were studied. From them, an extensive genealogical reconstitution was performed. Probands and relatives were interviewed using the structured interview CIDI and DSM-III-R check-list. Schizophrenia was diagnosed using DSM-III-R criteria. Complex segregation analysis was done using Pointer program. RESULTS: The hypothesis of a multifactorial inheritance, without the participation of major genes, could not be rejected. Likewise, the major dominant and co-dominant gene forms of transmission could not be rejected. CONCLUSIONS: Our results show the participation of a major dominant locus and a multifactorial component in the inheritance of schizophrenia, as has been reported elsewhere.

Adult↗

PubMed1993

[Prevalence of mental disorders at emergency service].

Aiming to know the frequency of mental disorders among patients consulting a general hospital emergency ward, 2834 medical records of such patients were retrospectively reviewed. 8.4% of consultations were due to mental disorders. Sixty four percent of patients consulting for mental disorders were women. Anxiety disorders comprised 57.6% of consultations due to mental disorders and intoxications 7.6%. Eighty percent of the latter were consequence of suicidal attempts, being the most common method the use of benzodiazepines. A low percent of these patients were referred to psychiatry. The low frequency of psychiatric referrals and the importance of psychiatric advice in emergency rooms is discussed.

Chile↗

PubMedDate not supplied

Premorbid personality aspects in mood and schizophrenic disorders.

This study examines premorbid personality traits from a self-reported and family-reported perspective on a group of unipolar major depression (n = 27), bipolar (n = 21), and schizophrenic (n = 16) recovered inpatients, and a control group (n = 21). Using the Munich Personality Test (MP-T Scales) of von Zerssen for self-reporting and family-reporting personality traits, and the Kischkel scale for the measurement of "intolerance of ambiguity," we found more "rigidity," less "esoteric tendencies," and more "intolerance of ambiguity" among unipolar depressive patients. Schizophrenic patients showed more esoteric tendencies and less "extraversion." Results confirm the hypothesis supported by many authors regarding a particular personality structure in unipolar major depression characterized by rigidity and ambiguity intolerance. This personality pattern for unipolar depressives seems to be different from the depressive personality disorder proposed by DSM-IV. Schizophrenic individuals differ by means of their self- and family-reported extraversion. Clinical and theoretical implications of these findings are discussed.

Adult↗

PubMedDate not supplied

Relationship between sex differences in onset of schizophrenia and puberty.

Some neurodevelopmental hypotheses of schizophrenia have postulated that sex differences in onset of illness could be explained by sexual dimorphism in onset of puberty, suggesting that early maturation accounts for the later onset of illness in women. The objective of this study was to analyse the relationship between age of menarche and age of onset of schizophrenia in a sample of Chilean patients. The medical records of 105 schizophrenic women diagnosed according to DSM-III-R criteria were studied. In all cases age of onset (first psychotic symptoms) and age of menarche were obtained. Pearson's correlation and student's t-test were used to analyse the data. The mean age of menarche in the sample of female patients (12. 98 years, S.D.=1.49) was significantly different from that of the general population of Santiago, Chile (12.53 years, S.D.=1.32) (t=2. 38; P<0.05). The mean age of onset of schizophrenia in female patients (19.92 years, S.D.=5.13) was significantly earlier in the Chilean sample than that reported in European and North American samples (P<0.05). No differences were observed when comparing the mean age at menarche. The subtypes with the earliest onset presented the earliest age of menarche and the subtypes with the latest onsets showed the latest ages at menarche. However, no correlation was observed between the age at onset of illness and the age at menarche, both in the total sample and in the analysis by subtype. The results of this study do not support a correlation between puberty and age of onset of illness.

Adult↗