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Biomedical subjects

C Santiago

Publications and source records attributed to C Santiago.

At least 19 recordsLinked to original sources
PubMed2006

ACTN3 genotype in professional endurance cyclists.

The Z-disk protein alpha-actinin-3 is only expressed in type II muscle fibres, which are responsible for generating forceful contractions at high velocity. Despite the evolutionary conservation of alpha-actinin-3, approximately one in every five Caucasians of European ancestry is totally deficient in this protein, due to homozygosity for a R577X polymorphism in the ACTN3 gene. This, together with the results of recent research on elite athletes, suggests that the "null" XX polymorphism might confer some advantage to endurance performance events. To test this hypothesis, we studied the frequency distribution of R577X genotypes in a group of 50 top-level male professional cyclists (26.9 +/- 0.4 yrs [mean +/- SEM]; VO2max: 73.5 +/- 0.8 ml x kg (-1) x min (-1)). Their results were compared with those of a group of 52 Olympic-class male endurance runners (26.8 +/- 0.6 yrs; VO2max: 73.3 +/- 0.8 ml x kg (-1) x min (-1)) and 123 healthy, sedentary male controls. All subjects were Caucasian, and of European ancestry. No significant differences (p > 0.05) were found between groups: RR: 28.5 %; RX: 53.6 % and XX: 17.9 % in controls; RR: 28.0 %; RX: 46.0 % and XX: 26.0 % in cyclists; and RR: 25.0 %; RX: 57.7 %; XX: 17.3 % in runners). No differences were found in indices of endurance performance (VO2peak or ventilatory thresholds) between athlete carriers of each R577X genotype. In summary, although the alpha-actinin-3 deficient XX genotype may be detrimental for sprint performance in humans, the R577X polymorphism of the ACTN3 gene does not appear to confer an advantage on the ability of male athletes to sustain extreme endurance performance.

Actinin↗
PubMed2006

Does the C34T mutation in AMPD1 alter exercise capacity in the elderly?

Ageing does affect functional capacity through several changes at the peripheral muscle level that impair the muscles capacity to produce energy and generate force. The skeletal muscle-specific isoform of AMP deaminase (AMPD) plays an important regulatory role in muscle metabolism and in determining energy charge. Since nearly 20 % of the general Caucasian population is heterozygous (CT) for the most common C34T mutation of the gene (AMPD1) encoding for this enzyme, it would be worthwhile to study if such a condition further increases the effects of ageing. Twenty-one women (61 - 80 yrs) served as subjects, and depending on the results of previous genotyping, were assigned to a group with the C34T mutation (heterozygous; n=4; mean+/-SEM age: 71+/-1 yrs) or with no mutation (n=17; 68+/-1 yrs). Several indices of maximal (peak oxygen uptake [V.O (2 peak)], peak power output) and submaximal endurance performance (ventilatory threshold, mechanical efficiency) and functional tests (one-mile walk test and a specific test of lower-body functional performance [sit-stand test]) were compared between the two groups. No significant differences were found in exercise capacity between both groups, e. g. V.O (2 peak) of 19.1+/-1.0 vs. 20.1+/-1.9 ml . kg (-1) . min (-1), V.O (2) at the VT of 11.9+/-0.6 vs. 12.9+/-1.0 ml . kg (-1) . min (-1), or time to complete the one-mile walk test (951+/-18 s vs. 962+/-61 s) and sit-stand test (9.9+/-0.2 vs. 9.2+/-0.2) (no mutation vs. C34T mutation, respectively). Although more research is necessary, it seems that the C34T mutation of the AMPD1, at least in heterozygous individuals, does not affect functional capacity in the elderly.

AMP Deaminase↗
PubMed2006

Does complete deficiency of muscle alpha actinin 3 alter functional capacity in elderly women? A preliminary report.

The sarcomeric protein alpha actinin 3 is localised to the Z line of fast fibres, which are responsible for generating forceful muscle contractions at high velocity. However, a substantial proportion of healthy humans are totally deficient in this protein as they are homozygous for a premature stop codon polymorphism (R577X) in the ACTN3 gene. The purpose of this preliminary study was to assess if the presence or absence of alpha actinin 3 influences the deleterious effects of ageing on muscle output and functional capacity.

Actinin↗
PubMed2005

Evaluation of organ procurement in an area under the influence of a training program.

INTRODUCTION: The procurement of organs was evaluated in an area of 1,450,000 inhabitants. This area provides two international programs and two training courses for transplant coordinators. One of them deals with the entire process of donation and transplantation, and the other is a monographic course about family consent and donation request. One transplantation coordinator manages the area. METHODS: The results of the last 6 years have been analyzed concerning the procurement of organ donors (related to brain death [BD] donors, exitus at the hospital, and the intensive care unit [ICU]); loss in the process, such as medically unsuitable; problem detection; and family refusals. RESULTS: During the past 6 years the donor potential increased from 1.67% to 4.06%. The BD by exitus in the ICU increased from 7% to 14.01% (the average in Spain 12.2%); the cases of BD in ICU beds increased from 0.5% to 1.31% (average in Spain 0.8%). The loss for medical exclusion criteria decreased from 27% to 20% and in family refusals from 19.7% to 13.6%. The efficiency of the process in percentage of actual donations by BD increased from 52.4% to 65.3% (average in Spain 49%). The actual donors per million population (PMP) increased from 37 PMP to 59 PMP. The average number of organs obtained from donors increased from 3.1 to 3.6, and the transplants increased from 2.7 to 3.04 per donor. The average waiting period for a renal transplant was reduced from 365 days to 199 days. CONCLUSION: The training of coordinators and the net system of regional coordinator, area coordinator, and hospital coordinator improved our donation rate.

Attitude to Death↗
PubMed2005

Association of the genetic polymorphisms of the renin-angiotensin system with kidney graft long-term outcome: preliminary results.

Recent studies have demonstrated some association between the renin-angiotensin system (RAS) activity and the development and progression of different entities as diabetes mellitus (DM) or chronic allograft nephropathy. To investigate these associations, we studied some gene polymorphisms of RAS in a group of renal transplant recipients. We retrospectively analyzed 42 patients who underwent a primary renal transplantation for 2 years. A subgroup of 23 patients (55%) was diagnosed with postransplant DM in accordance with American Diabetes Association 2001 criteria. We studied two RAS gene polymorphisms: the angiotensin-converting enzyme insertion/deletion (ACE I/D) and angiotensinogen (AGTM235T). Genotyping was performed by DNA purification and amplification with a polymerase chain reaction technique. The distributions of genotypes were ACE DD, ID, II: 33%, 48%, 19%; and AGT TT, MT, MM: 15%, 45%, 40%, respectively. We observed a progressive loss in renal function measured by creatinine clearance (Cockroft) in D-allele carriers (DD+ID) between the first and the second transplantation year: 65.3 +/- 4.3 vs 59.8 +/- 4.6 mL/min (P = 0.02); that was not seen in II patients: 68.8 +/- 4.6 vs 68.4 +/- 4 mL/min (P = 0.87). Fifty percent of D-allele carriers developed DM vs 25% of non-D-allele carriers (P = 0.19). Eighty-three percent of homozygous patients for the AGT-TT allele developed DM vs 35% of non TT patients (P = 0.04). There were no significant differences regarding recipient demographic characteristics, type of donor, number and severity of acute rejections, and immunosuppressant treatment between the groups. In conclusion, ACE D-allele seems to be associated with a poorer kidney graft long-term outcome. ACE D and AGT T alleles may be implicated in glucose metabolism disorders after transplantation.

DNA↗
PubMed2004

Treatment of severe chronic venous insufficiency using the subfascial endoscopic perforator vein procedure.

BACKGROUND: Before 1985, corrective surgical procedures for patients with chronic venous insufficiency and venous ulcers were performed using long incisions through diseased skin and subcutaneous tissues. The procedure, involving ligation of incompetent perforator veins, known as "the Linton operation," often was complicated by wound infections and poor healing. This changed in 1985 when G. Hauer demonstrated a new surgical technique for direct visual identification of the incompetent perforator veins using an endoscope in the subfascial space. This seminal contribution marked the advent of subfascial endoscopic perforator vein surgery (SEPS). METHODS: From 1996 to 2004, the authors group prospectively collected data on 110 patients with chronic venous insufficiency who underwent a SEPS procedure. Preoperative assessment of the limb's vascular status consisted of color-flow duplex ultrasound imaging and ascending and descending phlebography to locate vein valve incompetence, along with venous mapping. The ages of the patients ranged from 42 to 82 years (mean, 60 years). A total of 128 limbs underwent the SEPS procedure in the cohort of 110 patients. According to CEAP classification for venous limb disease, 60 limbs belonged to group C5 (skin changes, pigmentation, venous eczema, lipodermatosclerosis, healed ulcer) and 68limbs to group C6 (skin changes and active ulceration). RESULTS: The 110 patients underwent 128 SEPS procedures without significant morbidity. Of the 68 limbs in class C6, 54 showed ulcer healing within the follow-up period of 12 weeks. The remaining 14 limbs in class C6 achieved ulcer healing within 24 weeks. In this latter group, 10 patients had venous ulcers larger than 4 cm in diameter. These patients underwent a split-thickness skin graft at the time the SEPS procedure was performed. The grafts remained healed during a 2-year follow-up period. CONCLUSIONS: This study demonstrated the effectiveness of the SEPS procedure when incorporated into the overall treatment strategy for patients with chronic venous insufficiency. Minimal postoperative complications accompanied by ulcer healing and relief of lower extremity symptoms were achieved for all the patients, underscoring the important role of incompetent perforator veins in the formation of chronic venous insufficiency.

Adult↗
PubMed2002

[Efficiency of mycophenolate mofetil in the treatment of intermediate and posterior uveitis].

BACKGROUND: The severity of disease and the side-effects of long-term corticosteroid treatment support the rationale for other immunosuppressive drugs in the management of uveitis. Mycophenolate mofetil (MMF) is a selective inhibitor of ionosine monophosphate dehydrogenase and exerts its major effects by modulation of the function of T and B lymphocytes. This study was undertaken to evaluate the clinical effect of MMF in the control of intermediate and posterior uveitis. METHODS: A retrospective study of 18 consecutive patients with intermediate or posterior uveitis treated with MMF was performed. Activity of intraocular inflammation was graded according to the guidelines of the international uveitis study group before and during treatment with MMF. Furthermore, the ability of MMF treatment to reduce the steroid dosage and/or substitute other immunosuppressive agents with unacceptable side-effects (cyclosporin A, tacrolimus, azathioprine) was evaluated. RESULTS: The indication for treatment with MMF in all 18 patients (age range: 11-73 years) was either poor control of ocular inflammation by the previous immunosuppressive therapy or unacceptable side-effects of this therapy. The daily MMF dose was 2 g and therapy was combined with cyclosporin A and/or prednisolone. One patient received MMF monotherapy. Corticosteroids were discontinued in 4 patients and the steroid dose could be reduced in 14 patients following MMF therapy. Marked resolution of ocular inflammatory activity occurred in 13 patients. The most frequently observed side-effects of MMF were myalgia, fatigue, headache and gastrointestinal problems. CONCLUSION: MMF was effective in disease control in the majority of patients with intermediate and posterior uveitis and proved to be a useful second line immunosuppressant for refractory intraocular inflammatory disease with an acceptable profile of side-effects.

Adolescent↗
PubMed2001

Lupus-specific antiribonucleoprotein B cell tolerance in nonautoimmune mice is maintained by differentiation to B-1 and governed by B cell receptor signaling thresholds.

Systemic lupus erythematosus is an autoimmune disease characterized by the presence of autoantibodies. One of the unique targets of the immune system in systemic lupus erythematosus is Sm, a ribonucleoprotein present in all cells. To understand the regulation of B cells specific to the Sm Ag in normal mice, we have generated an Ig H chain transgenic mouse (2-12H Tg). 2-12H Tg mice produce B cells specific for the Sm that remain tolerant due to ignorance. We demonstrate here that anti-Sm B cells of 2-12H Tg mice can differentiate into Sm-specific peritoneal B-1 cells that remain tolerant. Differentiation to B-1 and tolerance are governed by the strength of B cell receptor signaling, since manipulations of the B cell receptor coreceptors CD19 and CD22 affect anti-Sm B cell differentiation and autoantibody production. These results suggest a differentiation scheme in which peripheral ignorance to Sm is maintained in mice by the differentiation of anti-Sm B cells to B-1 cells that have increased activation thresholds.

Animals↗
PubMed2001

Drosophila stem loop binding protein coordinates accumulation of mature histone mRNA with cell cycle progression.

Replication-associated histone genes encode the only metazoan mRNAs that lack polyA tails, ending instead in a conserved 26-nt sequence that forms a stem-loop. Most of the regulation of mammalian histone mRNA is posttranscriptional and mediated by this unique 3' end. Stem-loop-binding protein (SLBP) binds to the histone mRNA 3' end and is thought to participate in all aspects of histone mRNA metabolism, including cell cycle regulation. To examine SLBP function genetically, we have cloned the gene encoding Drosophila SLBP (dSLBP) by a yeast three-hybrid method and have isolated mutations in dSLBP. dSLBP function is required both zygotically and maternally. Strong dSLBP alleles cause zygotic lethality late in development and result in production of stable histone mRNA that accumulates in nonreplicating cells. These histone mRNAs are cytoplasmic and have polyadenylated 3' ends like other polymerase II transcripts. Hypomorphic dSLBP alleles support zygotic development but cause female sterility. Eggs from these females contain dramatically reduced levels of histone mRNA, and mutant embryos are not able to complete the syncytial embryonic cycles. This is in part because of a failure of chromosome condensation at mitosis that blocks normal anaphase. These data demonstrate that dSLBP is required in vivo for 3' end processing of histone pre-mRNA, and that this is an essential function for development. Moreover, dSLBP-dependent processing plays an important role in coupling histone mRNA production with the cell cycle.

Amino Acid Sequence↗
PubMed2000

Serum amyloid A protein in an echinoderm: its primary structure and expression during intestinal regeneration in the sea cucumber Holothuria glaberrima.

Serum amyloid A (SAA) proteins comprise a family of highly conserved apolipoproteins found in all mammals thus far investigated, and also in ducks and salmonid fishes. However, no invertebrate SAA homologues have been detected to date. Here we report the characterization of the first SAA homologue in a nonvertebrate deuterostome, the echinoderm Holothuria glaberrima. A 971-base-pair cDNA was obtained from a regenerating intestine cDNA library. The clone contains a 369-nucleotide open reading frame corresponding to a 122-amino-acid protein exhibiting a high degree of homology to members of the SAA superfamily. Sequence alignments of the holothuroid and vertebrate SAA proteins make evident a remarkable degree of conservation, even between phylogenetically disparate groups. Northern blots and immunohistochemistry show that SAA expression increases during regeneration of the holothuroid digestive tract as compared with normal nonregenerating tissue, and that the SAA protein is expressed by cells of the coelomic epithelium of the regenerating intestine. While SAA expression during the initial wound healing stage of regeneration is minimal, it increases during subsequent stages, peaking at day 15 of regeneration, concomitantly with lumen formation and the organization of the muscular layers of the regenerating digestive tract. Although in vertebrates SAA proteins may be part of a well-conserved anti-inflammatory mechanism, their exact biological function remains obscure. Our results suggest the possibility that SAA proteins, although structurally conserved, may possess enough functional diversity to participate in processes other than anti-inflammatory responses.

Amino Acid Sequence↗
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↗
PubMed2000

Integrative medicine: a paradigm shift in medical education and practice.

The use of alternative/complementary medicine has been increasing considerably. Conventional medicine must begin to address issues related to the use, safety, regulation, research and education of alternative/complementary medicine. Integrative medicine combines conventional medicine and alternative complementary practices. Integrative medicine is an innovative approach to medicine and medical education. It involves the understanding of the interaction of the mind, body and spirit and how to interpret this relationship in the dynamics of health and disease. Integrative medicine shifts the orientation of the medical practice from disease based approach to a healing based approach. It does not reject conventional medicine nor uncritically accepts unconventional practices. Integrative medicine is an effective, more fulfilling human approach to medicine based on the benefit of the patient by following good medicine practices in a scientific manner.

Complementary Therapies↗
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↗