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Biomedical subjects

C Santiago

Publications and source records attributed to C Santiago.

At least 19 recordsLinked to original sources
PubMed2000

Identification of Hox Gene Sequences in the Sea Cucumber Holothuria glaberrima Selenka (Holothuroidea: Echinodermata).

The Echinodermata is a unique animal group forming an early branch in the deuterostomes phylogenetic tree. In echinoids and asteroids a single Hox cluster with nine cognates of the vertebrate Hox paralogous groups has been reported, but no data are available from other echinoderm classes. We report here nine Hox-type sequences from the sea cucumber Holothuria glaberrima, a member of the class Holothuroidea. Partial homeodomain sequences were amplified by polymerase chain reaction from genomic DNA and from a regenerating gastrointestinal tract complementary DNA library. Sequence analyses suggest that the holothuroid cluster has at least three genes of the anterior, one of the medial, and five of the posterior groups. This is the first evidence of five posterior sequences in echinoderms.

Journal Article↗
PubMed1998

Bovine babesiosis and anaplasmosis follow-up on cattle relocated in an endemic area for hemoparasitic diseases.

A multiplex PCR/DNA probe assay was used to monitor Babesia bovis, B. bigemina and Anaplasma marginale infection in cattle introduced to a Boophilus microplus-infested area in Veracruz, Mexico. Eight intact, 18-month-old, cross-bred beef cattle (four naive, Group A; four Babesia species--premunized, Group B) were immediately exposed to ticks after arrival and were clinically monitored from day 6 to day 98 post-exposure (PE) to ticks. Blood sample analysis for DNA detection by the MPCR/DNA probe assay showed that Group A animals were infected with B. bovis from day 11 up to day 22 PE, requiring treatment on days 17-20. Group B animals were detected positive to B. bovis on days 17-20, did not require treatment and remained persistently infected from days 70 to 84 PE. Treatment of Group A animals delayed the infection with B. bigemina. These animals became positive to the parasite on days 63-77 PE. In contrast, Group B animals (untreated) showed B. bigemina infection on days 21-26 and 63-84 PE. One animal was positive for A. marginale infection on days 63-66 PE, the rest of the animals became so on days 80-98 PE. All infected animals required treatment with oxytetracycline. Monitoring the triple hemoparasite infection with the MPCR/DNA probe assay provided important epidemiological information. Thus, precautionary measures can be established when cattle are moved to a babesiosis/anaplasmosis risk area.

Anaplasma↗
PubMed1998

Prioritisation in speech and language therapy departments in Scotland and Malaysia.

This study investigates how prioritisation in health services have influenced speech and language therapy (SLT) services in Scotland in prioritising their caseload. Additionally, it evaluates how current prioritisation systems may contribute towards the development of the SLT service in Malaysia. Health, education and social agencies in Malaysia were contacted and a literature review was conducted. Information on prioritisation systems used in Malaysia was unavailable. Prioritisation systems from seven SLT departments within Scotland were investigated, of which three SLT managers took part in semi-structured interviews. The findings show that prioritisation is influenced by a combination of factors and that the principles could only be applied to the Malaysian SLT service if consideration is given to the political, economical, social, geographical and cultural factors.

Health Priorities↗
PubMed1997

Successful transplantation of organs retrieved from donors with bacterial meningitis.

BACKGROUND: The shortage of organs for transplantation is the most important factor limiting the number of transplants performed. Consequently, in recent years, criteria for considering a patient as a potential organ donor have been broadened. METHODS: From 1995 through 1996, we have retrieved organs from five donors who were brain dead because of bacterial meningitis. The causative microorganisms were Neisseria meningitidis in one patient, Streptococcus pneumoniae in three patients, and Escherichia coli in one patient. Fifteen organs were retrieved and transplanted into 16 recipients. All the donors and recipients received adequate antibiotic therapy. RESULTS: None of the recipients developed infectious complications caused by the meningeal pathogens. After a follow-up ranging from 4 to 30 months, 12 patients are alive with functioning grafts. The cause of death was noninfectious in the four patients who died. CONCLUSIONS: Our study demonstrates that patients with brain death caused by bacterial meningitis due to meningococci, pneumococci, or E coli may be suitable organ donors. Transplantation of organs from such donors does not increase the risk of infection transmission to the recipient, provided that both donor and recipient had received adequate antibiotic therapy.

Adolescent↗
PubMed1997

Management of twin pregnancies with fetal trisomies.

OBJECTIVE: To examine options of management and outcome of twin pregnancies affected by fetal trisomies. DESIGN: Retrospective study. SETTING: Research Centre for Fetal Medicine. POPULATION: Twenty-seven twin pregnancies affected by fetal trisomy. METHODS: A computer search was made of our database for twin pregnancies concordant or discordant for trisomies. The data were reviewed for gestation at diagnosis of the chromosomal abnormality, management and pregnancy outcome. MAIN OUTCOME MEASURES: Pregnancy management and outcome in relation to type and gestation at diagnosis of the trisomies. RESULTS: There were seven cases where both fetuses were trisomies and in these the parents opted for termination of pregnancy; termination was also performed in another pregnancy where one fetus had trisomy 18 and the chromosomally normal co-twin had a major facial cleft. In 19 cases one fetus had either trisomy 21 (n = 14) or trisomy 18 (n = 5) and the other was normal. Selective fetocide was carried out in 13 of 14 pregnancies discordant for trisomy 21 and in one of the five with trisomy 18. In the four cases discordant for trisomy 18 that were managed expectantly, the trisomic baby died in utero or in the neonatal period, whereas the normal co-twin was liveborn at 33 to 40 weeks (median 37). In the 14 cases of selective fetocide, the chromosomally normal co-twin was live born at 24 to 41 weeks of gestation (median 38), and there was a nonsignificant inverse correlation between the gestation at fetocide and gestation at delivery. CONCLUSIONS: In twin pregnancies discordant for fetal trisomies the main determinant in deciding whether to perform selective fetocide or adopt expectant management is the degree of lethality of the chromosomal defect.

Abortion, Induced↗
PubMed1997

Identification of developmentally regulated sea urchin U5 snRNA genes.

A PCR approach was used to isolate repeated U5 small nuclear RNA (snRNA) genes from the sea urchin Lytechinus variegatus. A 1.3 kb repeat, LvU5.0, and three other variants, LvU5.1-U5.3, that differ in the coding region and in the proximal sequence element (PSE) region were isolated. Southern Blot analysis indicate that the U5 snRNA genes, unlike other embryonically expressed snRNA genes (U1, U2 and U6), are not found in a simple tandem repeat, but instead, exist in several heterogeneous clusters each with a small number of genes. The U5 PSE has limited sequence similarity with the other sea urchin PSEs. However, when used in a mobility shift assay the U5 PSE forms a protein/DNA complex that is very similar to the complex formed with the U6 PSE. An RNase protection assay used to monitor the accumulation of U5 snRNA during development shows that at least two U5 variants are coordinately expressed during embryogenesis.

Animals↗
PubMed1997

[Monotherapy with vigabatrin in the treatment of West's syndrome].

INTRODUCTION: Vigabatrin (VGB) was specifically synthesized to enhance inhibitory GABAergic transmission by elevating GABA levels via irreversible inhibition of GABA transaminase. MATERIAL AND METHODS: This study was conducted to determine the efficacy of VGB introduced as monotherapy in 26 children fulfilled the criteria for diagnosis of West syndrome. Duration of follow-up was 24 months. RESULTS: Following the introduction of VGB, 13 patients became seizure free, a special efficacy in one case of tuberous sclerosis. Relapses of infantile spasms occurred in 8 infants, generalized seizures developed in 4 infants, and partial seizures in 3, of whom 2 were eventually rendered seizure-free by increasing the dose. EEG features and age affecting the response rate. VGB has been well tolerated in children with agitation being the most commonly reported side effects, and one case required discontinuation of therapy. CONCLUSIONS: VGB seems to be an effective an safe antiepileptic drug as primary monotherapy for West syndrome.

Adrenocorticotropic Hormone↗
PubMed1996

[Post-traumatic arterial priapism resolved using supraselective embolization].

Presentation of a new case of high flow priapism in a patient with recent background of perineal traumatism. Diagnosis, already inferred through anamnesis, was later suspected from the results of blood gasometry in cavernous bodies, and eventually confirmed by Eco-Doppler. A revision of the related literature revealed a total of 20 patients in whom supraselective embolization has been used as the therapeutical approach, Bucrylate being used in only two of them. Finally, a few considerations are contributed on the therapeutical management of these patients and the relevance of a correct diagnosis of the two distinct groups of priapism, since they differ considerably in terms of treatment.

Adult↗
PubMed1995

Fetal exomphalos and chromosomal defects: relationship to maternal age and gestation.

In an ultrasound screening study involving 15,726 viable, singleton pregnancies at 11-14 weeks of gestation, exomphalos was diagnosed in 0.11% of the cases and, in those with exomphalos, the frequency of trisomy 18, trisomy 13 or triploidy was 61%. The corresponding frequencies of exomphalos of fetuses with these chromosomal defects were 22.5%, 9.1% and 12.5%, respectively. The median maternal age of the screened population was 33 (range 15-48) years, which is higher than in all pregnancies in England and Wales. Expected prevalences of trisomy 18, trisomy 13 and triploidy in the total population were derived on the basis of the age distribution of all deliveries in England and Wales and maternal and gestational age-specific risks for these chromosomal defects. From these numbers and the observed frequencies of exomphalos in association with the various chromosomal defects, it was estimated that the prevalence of exomphalos in a population with the maternal age distribution of all deliveries in England and Wales was 7.4 per 10,000 at 12 weeks of gestation, and this decreased to 3.5 at 20 weeks and 2.9 in live births. The estimated frequency of chromosomal defects in fetuses with exomphalos decreased from 39.4% at 12 weeks of gestation to 27.5% at 20 weeks and 14.4% in live births. The prevalence of chromosomal defects in 153 fetuses with exomphalos referred to our center at 16-26 (median 20) weeks of gestation was not significantly different from that predicted in an unselected population. However, the reported frequency of chromosomal defects in a total of 299 neonates with exomphalos (9.3%) was significantly lower than expected in an unselected population. This study demonstrates that the prevalence of a fetal abnormality and the frequency of associated chromosomal defects depends on the maternal age and gestational age distributions of the populations examined.

Adult↗
PubMed1995

First trimester fetal nuchal translucency.

This review examines the development of a new method of screening for Down's syndrome based on the combination of fetal nuchal translucency thickness, maternal age and maternal serum biochemistry at 10-14 weeks of gestation. This method can potentially identify more than 80% of affected fetuses for a false-positive rate of less than 5%.

Chorionic Gonadotropin↗
PubMed1992

Evolution of lipid profiles in long-term peritoneal dialysis.

Serial lipid profiles of 102 patients starting chronic ambulatory peritoneal dialysis (CAPD) in our renal unit from January 1985 to December 1990 were collected retrospectively. Transient triglyceride elevation was noted during the first two years of CAPD but declined to normal levels even lower than those at baseline by 60 months. Total cholesterol, HDL and LDL cholesterol levels did not change significantly. Lipid-lowering agents were begun in 17 patients before initiating CAPD, 5 of whom achieved lipid profiles warranting cessation of therapy. Five other patients started treatment while on CAPD. No statistical difference in patient mortality was found when patients hyperlipidemic at the initiation of CAPD were compared to their normolipemic counterparts. We conclude that the return to normal plasma triglyceride levels after transient triglyceride elevation during long-term CAPD implies that adaptative mechanisms of triglyceride production in response to chronic glucose overload may ensue.

Adolescent↗
PubMed1989

A developmental switch in sea urchin U1 RNA.

The sequence of U1 RNA has been determined in the eggs and embryos of two sea urchins, Lytechinus variegatus and Strongylocentrotus purpuratus. In both species the sequence of the U1 RNA changes as the embryos progress through development. The sequence of the major U1 RNA in the eggs of the two species differs in two nucleotides, while the sequence of the U1 RNA present in the late embryos and somatic tissue is identical in the two species. The U1 RNA in eggs and early embryos is primarily derived from the tandemly repeated gene set, which is not expressed in somatic tissues.

Animals↗
PubMed1989

Expression of the U1 RNA gene repeat during early sea urchin development: evidence for a switch in U1 RNA genes during development.

The majority of the genes for U1 RNA are organized in tandemly repeated units in the sea urchin. To assess the level of expression of these genes in the sea urchin Lytechinus variegatus, we measured the transcription of sequences 3' to the gene. The tandemly repeated U1 genes are expressed in morula and continue to be expressed at high rates until 2 hr after hatching, at which time the rate of expression of all the U1 genes and the tandemly repeated U1 genes declines sharply. By the gastrula stage the synthesis of total U1 RNA has declined by a factor of 8. The major tandemly repeated genes are inactive by this time, although other U1 genes remain active. The sequence of U1 RNA synthesized late in embryonic development differs from the sequence of U1 RNA encoded by the tandemly repeated set of U1 RNA genes, indicating that there must be other U1 RNA genes that are active late in embryonic development.

Animals↗
PubMed1988

An improved circular tilt-cage shows that intrahypothalamic injections of sulpiride increase locomotion.

A circular tilt-cage was designed and constructed to measure locomotor activity in rats. Some improvements in relation to previously described circular tilt-cages, as the easy calibration and the automation of the data collection, were introduced. The detection system was built interfacing the actimeters through a circuit board to a Casio FP-200 computer. The interface, the computer and the software can be used to count lever presses or other kind of switch closures. This apparatus was used in the present report to quantitate the locomotor activity induced by sulpiride injected in the perifornical region of the lateral hypothalamus. Bilateral injections of sulpiride (8 micrograms/0.5 microliters) increased locomotion immediately after the injections and for the next 75 min. Bilateral amphetamine (20 micrograms/0.5 microliters) did not change activity. Several doses of sulpiride (2, 4, 8, and 16 micrograms/0.5 microliters) increased activity in a dose-dependent fashion. These results are discussed in terms of the existence of postsynaptic D2 receptors in the lateral hypothalamus involved in inhibition of locomotion.

Animals↗
PubMed1987

Liposomes with polyribonucleotides as model of precellular systems.

A study of the encapsulation of poly(U) and poly(C) within liposomes made from dipalmitoylphosphatidyl choline (DPPC), from egg yolk phosphatidyl choline (PC), and from PC with cholesterol (CHOL) was made. The liposomes were prepared under anoxic conditions following the reverse-phase evaporation method. Determinations showed that 36 to 70% of the available lipids form liposomes and 2 to 5% of the polyribonucleotides can be entrapped by liposomes. The encapsulation of polyribonucleotides has also been measured in the presence of urea, cyanamide and Zn++, condensing agents in prebiotic polymerization reactions. DPPC and PC:CHOL liposomes were formed in the presence of 1.0 M urea, although no PC liposomes were formed. The three types of liposomes were readily formed at 0.01 M urea, but in no case an enhancement of encapsulation efficiency of poly(U) was observed due to the presence of urea. Similar results were obtained with cyanamide. An enhanced encapsulation of poly(U) by the three types of liposomes was observed when Zn++ was in the range of 0.001 to 0.01 M. Poly(U) encapsulation was 15 to 25 times higher when liposomes were prepared from DPPC at 0.01 M Zn++. Similar results were obtained with poly(C). The advantages of DPPC-polyribonucleotide liposomes as precellular systems are discussed.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1986

Structure and expression of a second sea urchin U1 RNA gene repeat.

There are two tandemly repeated sets of U1 RNA genes in the sea urchin L. variegatus. Each of these genes is present in a 1.4 kb repeat defined by a HindIII site about 450 bases 5' to the gene. The sequences of a member of both repeating units (U1.1 and U1.2) has been determined. The repeats are nearly identical for 550 nucleotides 5' to the gene but show great divergence starting 30 nucleotides 3' to the gene, just after the CAAAGAAAGAAAA sequence thought to be required for 3' end formation. The other boundary between the conserved and non-conserved sequences is a polypyrimidine sequence (on the strand which codes for U1 RNA). Both of these repeats are expressed in blastula stage embryos, as judged by transcription of unique sequences 3' to the gene in nuclei isolated from blastula stage embryos. At least some of the two types of repeats are interspersed, since representatives of both repeat types on a single gamma phage isolated from a gene library. The sequence of the U1 RNA in L. variegatus eggs and embryos corresponds to the sequence of the U1 repeat.

Animals↗