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Biomedical subjects

C Valencia

Publications and source records attributed to C Valencia.

16 recordsLinked to original sources
PubMed2003

[Leukoaraiosis. Clinical importance and prognosis].

Advance in the health care systems, in medical knowledge and improvements in quality of life have contributed to the fact that life expectancy of the persons in developed countries exceeds 80 years of age. This has made it possible to observe the increase in frequency of common diseases of the elderly, one of the most relevant of which is dementia. The two most frequent etiologies of dementia are the degenerative one, with Alzheimer's disease (AD) as the main cause, and those of vascular etiology or vascular dementia, within which subcortical arteriosclerotic encephalopaty or Binswanger's disease (BD) are found with low prevalence. Since, on one hand, diagnosis of the dementias is not enough or definitive by clinical means, and on the other hand, the pathological diagnosis does not modify the evolution of disease, emphasis is presently placed on diagnosis by neuroimaging studies. In recent years, with the coming of the computerized tomography (CT) and the magnetic resonance (MR), it has been possible to observe lesions in the white matter of the brain hemisphere in patients with these two etiologic groups of dementias, that is, degenerative and vascular, as well as in elderly patient without cognitive deterioration, with or without vascular risk factors.

Alzheimer Disease↗
PubMed2003

[Asystolias in the acute phase of brain stroke. Report of a case].

Brain areas involved in heart autonomic control are not well characterized. Insulae have been proposed as control centers. A lesion in these areas may induce a cardiac autonomic dysfunction (arrhythmias, atrioventricular conduction abnormalities). Asystolia has not been previously reported. A 65-year-old man suffered an acute ischemia of the right middle cerebral artery (MCA) territory. NIHSS score was 19 points. Brain CT scan was normal. Transcranial Doppler (TCD) showed occlusion of the right MCA. Fibrinolysis was initiated 135 minutes after stroke onset with TCD monitoring. Twenty minutes later he suffered cardiac arrest with asystolia trace in the ECG monitor. Fibrinolysis was stopped during resuscitation. Four minutes later, he recovered with the same NIHSS score. Aggressive resuscitation maneuvers were not necessary. A repeated brain CT scan showed infarct signs in the whole MCA territory and a new TCD did not show any change. Serial blood analyses including cardiac nzymes were normal. The patient experienced four brief cardiac arrests in the next nine hours, so a temporary cardiac pacemaker was placed for four days. He was treated with aspirin and was discharged 14 days after admission. He has not experienced recurrences during a 6-month follow-up. We could not diagnose the etiology of the cardiac arrests. All the episodes occurred in the acute stroke stage and arrhythmia, atrioventricular block, myocardial ischemia or structural lesions were not found in the cardiac study. We propose that ischemia in the right insula induced sudden and transitory interruptions of the sympathetic cardiac tone.

Aged↗
PubMed2001

Differential tissue growth and patterns of cell death in mouse limb autopod morphogenesis.

Programmed cell death (PCD) is considered one of the most important cellular processes in the morphogenesis of organs and tissues during animal development. Although the embryonic limb has been established as a classic model for the study of PCD, detailed studies on this process' contribution to morphogenesis are still lacking. In the present work, using modern computer-aided techniques, we estimated the contribution of PCD to mouse limb morphogenesis. For the detection of apoptotic cell death, we stained whole embryonic limbs with acridine orange or, in some instances, used the TUNEL technique, and visualized the tissues by confocal laser scanning microscopy. We found that cell death patterns are dynamic during limb development, and occur in gradients oriented with the main limb axes, anteroposterior, dorsoventral and distoproximal. Interdigital apoptosis in the autopod was initially detected at the most distal region, and then more proximally as development proceeded. Interestingly, we found that digit separation is more pronounced on the dorsal side, contrary to what is expected from the apoptotic cell distribution, which shows more abundant cell death in the ventral region. Using 2-D and 3-D models, we found that most digit individualization occurs rather by digit growth than by interdigital cell death. Therefore, digits do not mainly individualize by degeneration of preformed interdigital tissue, but probably by a dynamic balance between proliferation and cell death, reducing interdigital growth, which results in protrusion of digits. We determined the expression pattern of fgf-8 during the period of digit individualization, as the product of this gene could participate in defining the limb growth pattern. Initially, fgf-8 expression was coincident with the apical ectodermal ridge, but when cell death was first detected in the interdigits, fgf-8 expression became restricted to the tip of the growing digits. Therefore, FGF-8 could be one of the factors responsible for differential digit-interdigit growth, and might also act as a survival factor on interdigital tissue. We also found that the expression patterns of rar-beta, bmp-2, bmp-4, bmp-7, msx-1, and msx-2 genes, proposed to be involved in the activation of interdigital cell death, did not overlap with, or were not highly expressed in the major zones of cell death in the developing limb.

Animals↗
PubMed2001

Blood pressure variability and leukoaraiosis amount in cerebral small-vessel disease.

OBJECTIVES: To analyze the correlation between blood pressure (BP) variability and leukoaraiosis (LA) amount in patients with symptomatic cerebral small-vessel disease. MATERIALS AND METHODS: We included 25 hypertensive patients: 13 with Binswanger's disease (BD) and 12 with a first-ever lacunar infarction (LI). Baseline office BP was obtained for 3 consecutive weeks. From a 24-h ambulatory BP monitoring performed 1 week later we obtained average systolic (SBP) and diastolic (DBP) BP for daytime, nighttime and 24-h periods. SBP and DBP variability was defined as the within-subject standard deviation of all readings. A standardized cerebral MR was performed in each patient and an LA score was calculated. RESULTS: No statistically significant correlation was obtained between the LA score and any of the following BP values: 1) Baseline SBP and DBP; 2) 24-h, daytime or nighttime SBP and DBP, and 3) 24-h, daytime or nighttime SBP and DBP variability. CONCLUSION: Increased BP variability is not associated with greater amounts of leukoaraiosis.

Aged↗
PubMed2001

Blood pressure variability in Binswanger's disease and isolated lacunar infarction.

UNLABELLED: To determine whether blood pressure (BP) variability is increased in hypertensive patients with Binswanger's disease (BD), we studied two samples of consecutive treated hypertensive patients: (1) 11 with BD (mean age 71.3 +/- 5.2 years); (2) 16 with lacunar infarction (mean age 65.2 +/- 8.3 years) without cognitive impairment. An averaged baseline office BP was obtained for 3 consecutive weeks. Ambulatory BP monitoring was then carried out to obtain the averaged mean systolic (SBP) and diastolic BP, and BP variability was defined as the standard deviation of consecutive BP values. RESULTS: Diurnal SBP variability was significantly increased in the BD group (p = 0.04). However, with the analysis of covariance for age and baseline office BP, the difference was no longer significant (p = 0.17 and p = 0.09, respectively). We conclude that increased BP variability in BD patients is probably due to older age and increased baseline office BP. Increased BP variability may be a risk factor for small-vessel disease, but not for cognitive impairment.

Age Factors↗
PubMed2000

[Prevalence of the Chlamydia trachomatis in neonatal conjunctivitis determination by indirect fluorescence and gene amplification].

BACKGROUND: Chlamydia trachomatis is one of the most common identifiable infectious agents in neonatal conjunctivitis. It also causes pneumonitis, that is preceded by conjunctivitis in one third of cases. AIM: To asses the prevalence of Chlamydia trachomatis in newborns with conjunctivitis. PATIENTS AND METHODS: In 162 newborns, coming from 14 Primary Health Centers from Santiago de Chile, C. trachomatis was detected by indirect fluorescence and two polymerase chain reaction (PCR 1 and 2), which amplified different sequences from the common endogenous plasmid. Those patients with positive indirect fluorescence and PCR 2 were defined as infected: RESULTS: The prevalence of C. trachomatis was 8%, and the distribution of the positive cases was similar in the different Health Centers. Other isolates were: S. aureus (9.8%), S. pneumoniae (8%), S. viridans (6.2%) y H. influenzae (5.5%). CONCLUSIONS: The prevalence of C. trachomatis in neonatal conjunctivitis in Chile is similar to that of developed countries. Therefore, C. trachomatis should be considered in the election of antimicrobials for the treatment of neonatal conjunctivitis, to avoid ocular and respiratory complications.

Chile↗
PubMed2000

Expression of E6 and E7 papillomavirus oncogenes in the outer root sheath of hair follicles extends the growth phase and bypasses resting at telogen.

Hair follicle growth cycle proceeds through a series of stages in which strict control of cell proliferation, differentiation, and cell death occurs. Transgenic mice expressing human papillomavirus type 16 E6/E7 papillomavirus oncogenes in the outer root sheath (ORS) display a fur phenotype characterized by lower hair density and the ability to regenerate hair much faster than wild-type mice. Regenerating hair follicles of transgenic mice show a longer growth phase (anagen), and although bulb regression (catagen) occurs, rest at telogen was not observed. No abnormalities were detected during the first cycle of hair follicle growth, but by the second cycle, initiation of catagen was delayed, and rest at telogen was again not attained, even in the presence of estradiol, a telogen resting signal. In conclusion, expression of E6/E7 in the ORS delays entrance to catagen and makes cells of the ORS insensitive to telogen resting signals bearing to a continuous hair follicle cycling in transgenic mice.

Animals↗
PubMed1999

[Colonic perforation secondary to ileocecal tuberculosis. Report of one case].

We report a 44 years old male, presenting with an eight months history of right lower quadrant pain, diarrhea and weight loss. Colonoscopy showed a proliferative and ulcerated lesion in the cecum, with necrotic areas. Barium enema showed an extensive irregular stenosis with rigidity of cecum and ascending colon. The endoscopic biopsy showed numerous granulomas with giant multinucleated cells of Langhans type. A right colectomy was performed with a good postoperative evolution. Anti tuberculosis treatment was started two weeks later and was well tolerated. The patient is currently asymptomatic after two years of followup.

Adult↗
PubMed1998

[Radical resective surgery for the management of rectosigmoidal endometriosis. Clinical case].

We report a 35 years old female with a profound rectosigmoidal endometriosis, who had been subjected to multiple laparoscopic procedures and open surgery due to infertility in the last five years. Main presenting symptoms were cyclic hematochezia during the menstrual periods associated to pelvic pain. Colonoscopy was inconclusive, barium enema showed a marked stenosis of the zone, appearing as an extrinsic compression. CAT scan showed a homogeneous, solid parauterine mass. During surgery, an inflammatory mass with multiple endometriotic foci was found. A low anterior resection with mechanical anastomosis was done, preserving the uterus and left adnexa. Two months later, the patient became pregnant and an elective cesarean section was done at 38 weeks of gestation, giving birth to a healthy newborn. Radical resective surgery for rectosigmoidal endometriosis is indicated in patients with intense and recurrent symptoms in whom hormonal treatment has failed and when a tumor cannot be discarded. The fertility rate, when adnexa and uterus are preserved, is 40% and symptomatic improvement is achieved in 85% of patients.

Adult↗
PubMed1993

[Experimental model of Lyme disease in rats].

BACKGROUND: An experimental model in rats can contribute to the understanding of the pathogenesis and improvement of treatment of Lyme borreliosis. OBJECTIVE: To develop a Lyme arthritis experimental model in Sprague-Davies rats. MATERIAL AND METHODS: An intraperitoneal inoculation of Borrelia burgdorferi in three groups of Sprague-Davies rats was made. The first group was inoculated with dead B. burgdorferi. The second group was inoculated with low virulence B-31 B. burgdorferi. The third group was inoculated with high virulence B-297 B. burgdorferi. RESULTS: After six months of follow-up, none of the rats in the first two groups presented arthritis whereas in the third group 18 rats (72%) developed arthritis in one or more joints. Histologic showed synovial hypertrophy and inflammatory infiltration composed of polymorphonuclear leukocytes, plasma and mast cells in the infected joint. B. burgdorferi was isolated in the liver and spleen cultures taken 14 days after inoculation in 40% of the rats inoculated with B-297 strain. CONCLUSION: An easy and inexpensive experimental model of Lyme arthritis in rats has been developed.

Animals↗
PubMed1989

[Demographic trends: birth spacing].

Two studies to measure children spacing in western metropolitan Santiago are compared. The first (1984-85) surveyed a sample of 687 mothers and the second 1,000. Deliveries took place at San Juan de Dios and Félix Bulnes hospitals (both state-finance) which provide medical care for medium and low income groups. Long spacing (5 years or more) accounted for the highest proportion of non-first born children (33.8% in 1984-85 with a significant increase to 40.1% in 1988) while short spacing (under 2 years) accounted for 19.2% in 1984-85 and 21.8% in 1988 (not significant). Mean birth weights were over 3,200 g in every spacing group. Despite the low illiteracy rate, predominant urban origin and having at least one child born before, high proportions of children were conceived despite the use of contraceptive measures (19.7% in 1984-85 and 22.5% in 1988). This contraceptive failure was less frequent among children born after longer spacings.

Birth Intervals↗
PubMedDate not supplied

Alien hand sign after a right parietal infarction.

Involuntary movements are unusual during or after acute stroke, and alien hand sign has not been reported after single parietal infarction. We report on a woman who presented with involuntary movements and a sense of alienness of her left upper limb following a right parietal infarction. This combination, that can meet the criteria for the 'alien hand syndrome', is rarely seen after acute lesions sparing the corpus callosum and the mesial frontal areas.

Aged↗
PubMedDate not supplied

[A system of multidimensional behavior assessment. A scale for parents of children from 6 to 11 years of age. Colombian version].

INTRODUCTION: Behavioral Assessment System for Children (BASC) has demonstrated to be useful in the diagnosis of Attention Deficit Disorder (ADD). PATIENTS AND METHODS: A randomized sample of 120 children, 6 to 11-year-old, participants from the school of the city of Medellín, Colombia, was selected. The sample was stratified by sex and two socioeconomic status (SES). Parents were asked to answer the BASC Parent Rating Scale (PRS) 6-11, authorized Spanish version. RESULTS: Cronbach's alpha coefficient was 0.85 for the clinical scale (9 items). It was 0.75 for the Adaptive Scale (3 items). A scale designed with 4 items to assess ADD (hyperactivity, attention problems, aggression, and conduct problems) showed an alpha coefficient of 0.82. Male children scored significantly higher than female (ANOVA, p < 0.05) in hyperactivity, conduct problems, and atypicality. Children from low SES scored significantly higher than children of high SES on the most of clinical measures (p < 0.05) and lower on the three adaptive measures. Cluster analysis selecting six clusters found a prevalence of 61.6% for normal male children. In the total sample there were a 4% at risk of DDA type II (inattentive) and 14% at risk of DDA type I (combined). CONCLUSIONS: BASC PRS (6-11) showed reliability and validity to assessing the behavior in Spanish speaking Colombian children.

Attention Deficit Disorder with Hyperactivity↗
PubMedDate not supplied

[Early introduction of dairy formulas in infant feeding].

Frequency, main features and factors associated to introduction of supplemental artificial milk formula at the first month of life were studied in 365 infants born from June 1st, through October 31, 1980, who were under control at a well baby clinic of Santiago, Chile, along years 1986 throughout 1987. By means of life-table analysis, time length of breast feeding was measured and compared in children with and without early formula introduction. In 22.5% of infants an artificial milk formula was given (82/365). In 80% of the cases (66/82) this was done upon instructions of health personnel on grounds of poor weight increase. Early introduction of formula negatively influenced duration of breast feeding which attained a median length of three months in artificially fed infant against ten months in those exclusively breast fed. Main features of infants and mothers prone to early formula introduction were maternal age 35 years or over, previous breast feeding shorter than six months, illegitimacy or first child, fourth or over in birth order, low birth weight and, or, hospital admission in the first four weeks of life. No influence was identified from educational level, of maternal work, desired or unwanted pregnancy, maternal nutritional status in the last three months of pregnancy, child spacing, type of delivery, sex and gestational age of the infants.

Age Factors↗