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Biomedical subjects

D Saavedra

Publications and source records attributed to D Saavedra.

At least 19 recordsLinked to original sources

Multiple agenesis and anhidrotic ectodermal dysplasia: a comparative longitudinal study of dental similarities and genetic differences in two groups of children.

AIM: Dental anomalies in shape and number may be present isolated or associated with other manifestations. In anhidrotic ectodermal dysplasia they occur more frequently and severely. The authors examined a group of children with similar dental anomalies but no other ectodermal or extra-ectodermal signs. METHODS: This study makes a comparative evaluation of similarities and differences of dental anomalies between two groups: A anhidrotic ectodermal dysplasia and B similar dental finding but without extra- dental anomalies. RESULTS: In group A, the average number of agenesis in primary teeth was 3.5 (upper) and 5.33 (lower); in permanent teeth it was 5.4 and 5.8, respectively. In group B, the average was 1.62 (upper) and 0.25 (lower) in primary teeth, and 4.0 and 4.25 in permanent teeth respectively, with no constant pattern of occurrence. The study of tooth morphology of both groups revealed numerous anomalies in both dentitions. No differences were found in the average number of agenesis and morphological anomalies in the permanent teeth between both groups, but in the primary dentition group B presented a lower degree of incidence. CONCLUSION: The presence of almost normal primary dentition (regarding to number), but with morphological anomalies, should lead to suspect their exacerbation in the permanent dentition.

Anodontia↗

Fetal dysmorphism in spontaneous abortions in a Mexican population.

OBJECTIVE: The purpose of this research was to find out the frequency and type of fetal dysmorphism in spontaneous abortions among the Mexican population. METHOD: A prospective study was carried out in all the cases of spontaneous miscarriages occurring at the 'Dr. Manuel Gea González' General Hospital in Mexico City, from July 1989 to June 1999. RESULT: Two hundred and one empty sacs and 1555 well-defined embryos or fetuses were analyzed. Dysmorphism was observed in 48% of the cases, malformations being the most frequently found. Among malformations the largest group corresponded to morphological alterations not recognized in the postnatal life, facial clefts and closure defects of the abdominal wall were the known malformations of the postnatal period most frequently found. The most common syndromic entities were suggestive of bone dysplasia and Turner phenotype. CONCLUSION: The frequency of fetal dysmorphism in spontaneous abortions is higher than in newborns. Its diagnosis is very important for genetic counseling.

Abnormalities, Multiple↗

Hematological and biochemical reference intervals for wild caught Eurasian otter from Spain.

Hematologic and serum chemistry reference intervals were determined from 33 wild caught Eurasian otters (Lutra lutra lutra) between November 1995 and May 1998 during a reintroduction project. Blood was obtained by jugular venipuncture after administration of ketamine and medetomidine. The mean, standard deviation, and range for 19 hematology parameters and 28 serum chemistry values are presented. There were no significant differences between sexes in most analytes. The results are in agreement with those reported previously for Eurasian otters with the exception of higher leukocyte and neutrophil counts, lower eosinophil and lymphocyte counts and higher activities for aspartate aminotransferase and creatine kinase. The Eurasian otters have lower erythrocyte counts but higher mean corpuscular volume and mean corpuscular hemoglobin values than the river otter (Lutra canadensis) in North America.

Animals↗

Reversible immobilization of eurasian otters with a combination of ketamine and medetomidine.

The efficacy and safety of the combination of medetomidine and ketamine was examined in order to establish an adequate chemical immobilization protocol in the Eurasian otter (Lutra lutra) for use during translocation projects in Spain. Thirty-eight Eurasian otters ranging in body mass from 3 to 8.7 kg (mean 5.3 kg) were successfully anesthetized on 82 occasions. The dosage of ketamine was 5.1+/-0.8 (3.4-6.6) mg/kg (mean +/- SD; range) combined with medetomidine at a dosage of 51+/-8 Rg/kg (34-66 microg/kg). In most cases anaesthetic effect occurred within 3 min and the mean induction time was 5.5+/-3.2 min. The mean pulse rate was 95 beats/min. The mean respiratory rate was 32 respirations/min while the relative oxyhemoglobin saturation was 93%. According to these results, this anesthetic protocol is considered safe and can be recommended in wild caught Eurasian otters for immobilization during translocation projects. It is safe, rapid and can be reversed when needed with atipamezole. However caution is required as heart depression resulting in bradychardia may occur.

Adrenergic alpha-Antagonists↗

A novel phenotypic pattern in X-linked inheritance: craniofrontonasal syndrome maps to Xp22.

Craniofrontonasal syndrome (CFNS, OMIM 304110) is a distinctive genetic disorder whose main clinical manifestations include coronal synostosis, widely spaced eyes, clefting of the nasal tip and various skeletal anomalies. CFNS originally was thought to be transmitted as an autosomal dominant trait, but recent studies suggest that it is X-linked dominant, whereby all daughters of males are affected, whereas none of their sons are affected. Here we report data confirming that CFNS is X-linked, mapping to a 13 cM interval in Xp22 with a maximum two-point lod score of 3.9 (theta = 0) at DXS8022 and a multipoint lod score of 5.08 at DXS1224. Detailed phenotypic analysis shows that females are more severely affected than males, a highly unusual characteristic for an X-linked disorder. CFNS represents the first multiple congenital anomaly syndrome with this unusual phenotypic pattern of X-linked inheritance.

Chromosome Mapping↗

Analysis of mRNA expression and cloning of a novel plasma membrane Ca(2+)-ATPase splice variant in human heart.

Four different plasma membrane Ca(2+)-ATPase (PMCA) genes and three sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) genes have been previously cloned and characterized. In this study we have investigated the expression of the mRNA encoding the various PMCA and SERCA proteins in fetal and adult human heart and placenta by the reverse-transcriptase-polymerase-chain-reaction (RT-PCR) and cDNA cloning. We have found that PMCA1 and PMCA4 genes were expressed in 8-, 12- and 20-week fetal heart and in adult heart. PMCA2 gene was expressed at low levels in adult heart but was not detected in fetal heart. PMCA3 mRNA was not detected in the heart nor placenta. In contrast, the mRNA encoding SERCA2a, SERCA2b and SERCA3 were expressed in all cardiac developmental stages. Multiple alternatively spliced mRNA transcripts which differ at splice site A and B/C of the PMCA1, PMCA2 and PMCA4 genes were detected in the human heart. Interestingly, a novel tissue specific variant of the PMCA4 gene was detected in both fetal and adult human heart but not in placenta that accounts for about 30% of the total PMCA4 mRNA variant expression. DNA sequence analysis of this novel variant revealed that it corresponds to the equivalent of the PMCA1d variant and accordingly we have named it PMCA4d. We cloned and sequenced eight cDNA inserts encoding for the PMCA1 and PMCA4 variants from a fetal human heart cDNA library confirming that these are the two main PMCA genes expressed in cardiac muscle.

Adult↗

Craniofrontonasal syndrome: study of 41 patients.

Of 41 patients with craniofrontonasal syndrome, 35 were female and 6 were male. Although most cases were sporadic, 7 familial instances were found. Craniofrontonasal syndrome represents a unique, incompletely understood X-linked disorder. Unusual manifestations in females included thick, wiry, and curly hair (49%), anterior cranium bifidum (6%), axillary pterygia (9%), unilateral breast hypoplasia (postpubertal; 11%), and asymmetric lower limb shortness (14%).

Adolescent↗

Cerebrofaciothoracic syndrome.

We report on a patient with a large septum pellucidum, hypodensity of gray matter, hypertelorism, and costovertebral anomalies. Only 5 previous cases have been described with this distinctive phenotype. Autosomal recessive inheritance seems likely.

Abnormalities, Multiple↗

Frontonasal dysplasia: analysis of 21 cases and literature review.

Twenty-one patients with frontonasal dysplasia were studied. A 2:1 male-to-female sex ratio and increased paternal and maternal ages at the time of conception were found. The significance is uncertain because of small sample size and lack of normal mean values for parental age in Brazil. Apparently, our series is the first to report macrocephaly (six cases). Our series also had a high frequency of patients with agenesis of the corpus callosum (12 cases), basal encephalocele (10 cases), lipoma of the corpus callosum (four cases), and mental deficiency (11 cases). Three patients had the combination of agenesis of the corpus callosum, mental deficiency, and micropenis. It is concluded that frontonasal dysplasia is pathogenetically heterogeneous, representing a regional defect which may not be a single developmental field or sequence. Causal genesis includes a dominantly inherited form, dup(2q), and autosomal recessive Shanske syndrome. Of unknown genesis are two subsets of frontonasal dysplasia patients: 1) the combination of agenesis of the corpus callosum, tibial hypoplasia, and hallucal duplication and 2) ophthalmofrontonasal dysplasia or oculoauriculofrontonasal dysplasia with associated ear tags and epibulbar dermoids.

Abnormalities, Multiple↗

Hypertelorism: interorbital growth, measurements, and pathogenetic considerations.

Normal pre- and post-natal changes in the interorbital distance are described. Causes of illusory hypertelorism include flat nasal bridge, epicanthic folds, exotropia, widely-spaced eyebrows, narrow palpebral fissures, and dystopia canthorum. Measurements of hypertelorism may involve soft tissues or bone, and a number of indices have also been proposed. Various types of measurements are evaluated and recommendations suggested. Possible pathogenetic mechanisms for hypertelorism include: early ossification of the lesser wings of the sphenoid; failure in nasal capsule development allowing the primitive brain vesicle to protrude into the space normally occupied by the capsule resulting in morphokinetic arrest in the position of the eyes; and disturbances of the cranial base in Apert syndrome. Associations with increased interorbital distance are also discussed: orofacial clefting, nonprotruding lipomas of the corpus callosum, calcification of the falx cerebri, duplication of the crista galli, wrinkling of the nose, and tissue tags of the nose. Finally, experimental models of hypertelorism in animals are discussed.

Abnormalities, Multiple↗

Safety and immunogenicity of the synthetic malaria vaccine SPf66 in a large field trial.

In the first field trial with synthetic malaria vaccine SPf66 in a large population naturally exposed to malaria, 9957 persons greater than 1 year old and residing on the Colombian Pacific coast received three doses of the vaccine. To evaluate vaccine safety, clinical observations were made 30 min and 48 h after each immunization. There were no adverse reactions in 95.7% of cases. In the 4.3% of cases with adverse reactions, local induration and erythema were the most frequent. In a randomly selected group of vaccinees, anti-SPf66 antibody titers were measured after the third dose: 93% of the vaccinees raised antibodies to SPf66. Among these, 55% had titers greater than 1:1600. These results demonstrate the safety and immunogenicity of the SPf66 vaccine in a large field trial.

Adolescent↗

Inherited impairment of nuclear androgen uptake as a cause of familial androgen insensitivity.

The endocrine and biochemical characteristics of four related 46,XY pseudohermaphrodite patients with the Reifenstein Syndrome are presented. All of them (6 and 9 years old, first generation, and 9 and 12 months old, second generation) exhibited ambiguity of external genitalia and a family pedigree characteristic of an X-linked pattern of inheritance. Serum basal levels of LH, FSH, testosterone (T), androstenedione and 5 alpha-dihydrotestosterone (DHT) were within normal limits. Administration of hCG induced a normal response in terms of serum T in three of the patients, with a concomitant increase in serum DHT. However, an abnormally elevated T: DHT ratio was found in two of these subjects on the day of maximal T response (T: DHT ratio, 24 and 27; normal range, 4-21). Genital skin-derived fibroblasts from all patients were studied for [3H]DHT uptake in a whole-cell monolayer assay. Three of the mutant strains exhibited values of [3H]DHT uptake at 37 degrees C within the lower limits of normality (39.4-47.05 fmol/mg protein/h; normal strains, 36-101 fmol/mg protein/h), whereas fibroblasts from the remaining patient presented a slightly decreased uptake (31.66 fmol/mg protein); when studied at 42 degrees C, all mutant strains behaved as the normal controls. The existence of a specific 4.6 S cytosol androgen receptor was clearly seen in the two mutant strains when analysed by sucrose gradient centrifugation. Nevertheless, in one of the mutant strains, a significantly low maximal nuclear [3H]DHT uptake was detected (173.6 fmol/mg DNA; control strain, 301.6 fmol/mg DNA). The overall data were interpreted as demonstrating the existence of an impaired uptake of the androgen-receptor complex at the nuclear levels as the cause of the incomplete phenotypic expression of androgen action in this family. In this setting, the presence of low peripheral 5 alpha-reductase activity may be considered as a secondary manifestation of the androgen insensitivity.

Androgens↗

Fetal mortality in sibships with one or more affected members with oral clefts.

We investigated the fetal mortality in 903 sibships with at least one member having cleft lip with or without cleft palate [CL(P)] and 213 with at least one individual affected with cleft palate (CP) derived from three different data sources in México. The frequency of fetal wastage (abortion and/or stillbirth) was not increased in sibships where the propositi had cleft lip and palate (CLP) as compared with cleft lip (CL) nor in those where index cases had a bilateral lesion as compared to a unilateral one, nor when the index cases with CL(P) were female rather than males, nor when the index case was a female with bilateral lesion as compared to males with a unilateral one. Similarly fetal mortality was not increased in sibships in which the propositus had CP compared to those in which the index case was a female. These findings are contrary to some reports that claim to support a two-threshold model according to which individuals reaching the first one would be born with an oral cleft, and those reaching the second would be aborted. Our results, together with others, suggest the possibility that liability to oral clefts is independent of liability to fetal wastage.

Abortion, Spontaneous↗