Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Front Health Serv ; 3: 1242796, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38028940

RESUMEN

Introduction: Immunizations are successful, cost-effective interventions for the control of infectious diseases and preventing mortality. Lockdown restrictions during the COVID-19 pandemic had adverse effects on child-health including access to immunizations. Our study aimed to document immunization status, describe caregiver experiences around accessing immunizations during the COVID-19 pandemic and identify any significant factors associated with immunization status. Methods: Caregivers, with children between the ages of 10 to 33 months, attending Tygerberg Hospital Paediatric Department were invited to complete an anonymous survey from 15th September-15th December 2022. Data was captured using a REDCap questionnaire and analysed using Stata Version 17. Results: 171 caregivers completed the survey. Immunizations were up to date in 81%. Most (155, 88%) agreed it was important to immunize their child. A third of caregivers (55) felt it was unsafe to attend the clinic and 37% (62) agreed it was difficult to attend. Caregivers receiving a social grant (p = 0.023) or who felt safe attending clinic (p = 0.053) were more likely to be up to date with immunizations. Three-quarters (128, 78%) were aware of recommendations to continue immunization. These caregivers were more likely to think it was important to immunize on time (p = 0.003) and to receive family encouragement (p = 0.001). Caregivers were more likely to attend clinic if they felt it was important to vaccinate on time (p < 0.001) or felt safe attending clinic (p = 0.036). Conclusion: Immunization rates were higher than expected but below global targets. Although caregivers feel immunizations are important, unknowns still instilled fear of attending clinics. Social factors such as family support and social grants improve vaccine seeking behaviour.

2.
S Afr Med J ; 110(5): 360-363, 2020 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-32657717

RESUMEN

Despite a substantial decline in childhood mortality rates in South Africa (SA), progress in neonatal mortality reduction has been much slower. Severe bacterial infections remain a leading cause of neonatal morbidity and a direct cause of 13.1% of neonatal deaths among babies >1 kg. The incidence of hospital-acquired infections, antimicrobial resistance and outbreaks of infections in SA neonatal units is substantial, and is possibly higher than the currently available estimates. The SA Neonatal Sepsis Task Force was launched in Port Elizabeth, SA, on 13 September 2019 to provide technical advice and guidance on surveillance for neonatal sepsis, infection prevention, case management, antimicrobial stewardship and containment of neonatal unit outbreaks.


Asunto(s)
Comités Consultivos , Programas de Optimización del Uso de los Antimicrobianos , Unidades de Cuidado Intensivo Neonatal , Sepsis Neonatal/epidemiología , Sepsis Neonatal/prevención & control , Infección Hospitalaria/epidemiología , Infección Hospitalaria/prevención & control , Brotes de Enfermedades , Farmacorresistencia Microbiana , Humanos , Recién Nacido , Control de Infecciones , Vigilancia de la Población , Sudáfrica/epidemiología
3.
S Afr Med J ; 108(10): 818-827, 2018 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-30421708

RESUMEN

BACKGROUND: A countrywide epidemic of Listeria monocytogenes (LM) in South Africa began in the first quarter of 2017, rapidly becoming the world's largest LM outbreak to date. METHODS: We describe the clinical course of neonates with culture-confirmed LM infection admitted to a tertiary neonatal unit at Tygerberg Hospital, Cape Town (1 January 2017 - 31 January 2018). Current epidemic LM cases were compared with a historical cohort of sporadic neonatal LM cases at our institution (2006 - 2016). The global literature on epidemic neonatal LM outbreaks (1 January 1978 - 31 December 2017) was reviewed. RESULTS: Twelve neonates (median gestational age 35 weeks, median birth weight 2 020 g) were treated for confirmed LM bacteraemia in 2017/18, presenting at a median age of 0.5 days. In 5 cases, neurolisteriosis was suspected. Three neonates died (25.0%) v. 8/13 neonatal deaths (61.6%) in the sporadic listeriosis cohort (2006 - 2016) (p=0.075). The institution's neonatal LM infection incidence increased significantly in 2017 from a historical rate of 0.17/1 000 live births to 1.4/1 000 (p<0.001). During the current LM epidemic, the crude neonatal fatality rate exceeded the average calculated global epidemic neonatal LM mortality (3/12 (25.0%) v. 50/290 (17.2%); p=0.448). Possible factors contributing to the high mortality rate in this epidemic LM neonatal cohort may include more virulent disease associated with sequence type 6 and the predominance of early-onset disease. CONCLUSIONS: Epidemic neonatal listeriosis at Tygerberg Hospital was associated with a predominance of bacteraemic, early-onset disease. Listeriosis-associated mortality rates were higher than previously published, but lower than the rate in a historical institutional cohort.


Asunto(s)
Bacteriemia/epidemiología , Infecciones Bacterianas del Sistema Nervioso Central/epidemiología , Epidemias , Enfermedades del Recién Nacido/epidemiología , Listeriosis/epidemiología , Bacteriemia/mortalidad , Peso al Nacer , Infecciones Bacterianas del Sistema Nervioso Central/mortalidad , Femenino , Edad Gestacional , Humanos , Incidencia , Recién Nacido , Enfermedades del Recién Nacido/mortalidad , Recien Nacido Prematuro , Listeriosis/mortalidad , Masculino , Sudáfrica/epidemiología , Centros de Atención Terciaria
4.
Int J Infect Dis ; 74: 16-23, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29935284

RESUMEN

BACKGROUND: Data on antimicrobial use among hospitalized children in Africa are very limited due to the absence of electronic prescription tracking. METHODS: This study evaluated antimicrobial consumption rates, the antimicrobial spectrum used, and the indications for therapy on a paediatric ward and in the paediatric intensive care unit (PICU) at Tygerberg Hospital, Cape Town, South Africa. Antimicrobial prescription and patient demographic data were collected prospectively from May 10, 2015 to November 11, 2015. For the same period, data on antimicrobials dispensed and costs were extracted from the pharmacy electronic medicine management system. The volume of antimicrobials dispensed (dispensing data) was compared with observed antimicrobial use (prescription data). RESULTS: Of the 703 patients admitted, 415/451 (92%) paediatric ward admissions and 233/252 (92%) PICU admissions received ≥1 antimicrobials. On the ward, 89% of prescriptions were for community-acquired infections; 29% of PICU antimicrobials were prescribed for healthcare-associated infections. Ampicillin and third-generation cephalosporins were the most commonly prescribed agents. Antimicrobial costs were 67541 South African Rand (ZAR) (5680 United States Dollars (USD)) on the ward and 210484 ZAR (17702 USD) in the PICU. Ertapenem and meropenem were the single largest contributors to antimicrobial costs on the ward (43%) and PICU (30%), respectively. The volume of antimicrobials dispensed by the pharmacy (dispensing data) differed considerably from observed antimicrobial use (prescription data). CONCLUSIONS: High rates of antimicrobial consumption were documented. Community-acquired infections were the main indication for prescription. Although pharmacy dispensing data did not closely approximate observed use, this represents a promising method for antimicrobial usage tracking in the future.


Asunto(s)
Antibacterianos/uso terapéutico , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Infección Hospitalaria/tratamiento farmacológico , Hospitales/estadística & datos numéricos , Ampicilina/uso terapéutico , Niño , Ertapenem/uso terapéutico , Femenino , Hospitalización , Humanos , Lactante , Unidades de Cuidado Intensivo Pediátrico/estadística & datos numéricos , Masculino , Uso Excesivo de los Servicios de Salud/estadística & datos numéricos , Meropenem/uso terapéutico , Pediatría/estadística & datos numéricos , Farmacias/estadística & datos numéricos , Sudáfrica
5.
S Afr Med J ; 108(11): 937-943, 2018 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-30645960

RESUMEN

BACKGROUND: Ampicillin to treat Listeria monocytogenes (LM) infection is empirically added to the treatment of infants (<3 months) with suspected sepsis or meningitis. OBJECTIVES: In view of limited LM cases, the paucity of South African (SA) data and an ampicillin shortage, our objective was to describe the occurrence of LM infections at Tygerberg Hospital (TBH), Cape Town, with the aim of rationalising the paediatric antibiotic policy. METHODS: An 11-year (2006 - 2016) retrospective descriptive study of children (<13 years) from TBH and referral hospitals with a positive blood or cerebrospinal fluid (CSF) culture for LM was conducted. RESULTS: Of 26 children with positive cultures for LM, 23 (88.5%) were <3 months of age; all were <10 days old. Approximately half (56.5%, 13/23) were born at or referred to TBH. Presentation was on the day of delivery in 46.2% (6/13), 92.3% were admitted to the neonatal intensive care unit (NICU), and 61.5% (8/13) died. Neonates treated at peripheral hospitals were statistically more likely than those treated at TBH to have a CSF culture obtained (90.0% v. 30.8%; p=0.005), and had higher platelet counts (239 × 109/L v. 107 × 109/L; p=0.004), lower C-reactive protein levels (64 mg/L v. 137 mg/L; p=0.013) and a lower mortality rate (0% v. 61.5%; p=0.002). The incidence of LM at TBH was 0.04/1 000 live births and 2.3/1 000 NICU admissions. CONCLUSIONS: As in other countries, the local neonatal LM incidence is low. Neonates present in the first week of life with severe disease and a high mortality rate. These data support a change in antibiotic policy, in keeping with international guidelines, limiting empirical ampicillin prescription to infants <1 month of age.

6.
Spinal Cord ; 54(5): 376-82, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26391189

RESUMEN

STUDY DESIGN: This was a cross-over efficacy study design. OBJECTIVE: To determine spasticity differences between static and dynamic standing training in individuals with spinal cord injury (SCI). SETTING: Vancouver, Canada. METHODS: Ten individuals with SCI who could stand with or without bracing or supports participated in both dynamic and static standing training (one session each, 2 days apart) using a Segway. The primary outcome was spasticity as measured by Visual Analog Scale (VAS), Modified Ashworth Scale (MAS) and electromyography (EMG) of the quadriceps, hamstrings, adductors and gastrocnemius. RESULTS: There was no statistically detectable difference in spasticity between dynamic and static standing training in individuals with SCI as measured by VAS, MAS or EMG, although there was a trend towards decreased spasticity after the dynamic training. CONCLUSION: There is no significant difference in spasticity outcomes between static and dynamic standing training on a Segway for individuals with SCI. SPONSORSHIP: This research was funded by Natural Sciences and Engineering Research Council of Canada and International Collaboration on Repair Discoveries.


Asunto(s)
Espasticidad Muscular/etiología , Equilibrio Postural/fisiología , Postura/fisiología , Traumatismos de la Médula Espinal/complicaciones , Adulto , Estudios Cruzados , Electromiografía , Potenciales Evocados Motores/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Índice de Severidad de la Enfermedad , Traumatismos de la Médula Espinal/rehabilitación , Escala Visual Analógica
7.
Int J Sports Phys Ther ; 9(1): 103-15, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24567861

RESUMEN

BACKGROUND: Athletes are routinely assessed medically prior to competition. Although standardized preparticipation examinations (PPEs) are available for able-bodied athletes, the literature lacks any validated equivalent for the athlete with disability (AWD). Since participation and level of competition is increasing in this population, evidence-based tools such as a standardized PPE form should be available for health professionals to assess AWD health and safety. AIM OF THE STUDY: To develop an AWD-targeted standardized preparticipation history evaluation (PPE history) using consensus-based expert recommendations. METHODS: Researchers developed a PPE history for critical evaluation of its content validity. Structured Delphi method for collecting and interpreting contributions from an expert panel using a series of questionnaires with controlled feedback was performed. Opinions based on the experience of related experts - physiotherapists, sports medicine physicians and physiatrists - were studied during each of the three survey rounds. The process was terminated once adequate consensus relating to the proposed PPE history document was reached. RESULTS: Majority consensus was reached for forty-nine of fifty-four items to create a refined ten section AWD-specific document to supplement the current standardized PPE. Modifications were made by researchers to accommodate the five items that did not reach statistical consensus. CONCLUSION: Consensus was reached on a variety of AWD-specific PPE items, including the disability-related history and functional review. Equipment issues represent a complex area of evaluation, worthy of future research and discussion. The current proposed PPE history tool is considered comprehensive and ready for application in a clinical setting as an adjunct to existing PPE tools. Injury research in the AWD population will provide guidance for refinement and further validation of this PPE history document. LEVEL OF EVIDENCE: 5.

8.
Anim Genet ; 45(2): 191-7, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24456574

RESUMEN

Female reproductive performance traits in pigs have low heritabilities thus limiting improvement through traditional selective breeding programmes. However, there is substantial genetic variation found between pig breeds with the Chinese Meishan being one of the most prolific pig breeds known. In this study, three cohorts of Large White × Meishan F2 cross-bred pigs were analysed to identify quantitative trait loci (QTL) with effects on reproductive traits, including ovulation rate, teat number, litter size, total born alive and prenatal survival. A total of 307 individuals were genotyped for 174 genetic markers across the genome. The genome-wide analysis of the trait-recorded F2 gilts in their first parity/litter revealed one QTL for teat number significant at the genome level and a total of 12 QTL, which are significant at the chromosome-wide level, for: litter size (three QTL), total born alive (two QTL), ovulation rate (four QTL), prenatal survival (one QTL) and teat number (two QTL). Further support for eight of these QTL is provided by results from other studies. Four of these 12 QTL were mapped for the first time in this study: on SSC15 for ovulation rate and on SSC18 for teat number, ovulation rate and litter size.


Asunto(s)
Sitios de Carácter Cuantitativo , Reproducción/genética , Porcinos/genética , Animales , Mapeo Cromosómico/veterinaria , Ligamiento Genético , Marcadores Genéticos , Genoma , Repeticiones de Microsatélite
9.
S Afr Med J ; 103(5): 304-8, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23971119

RESUMEN

OBJECTIVE: To validate a revised version of the paediatric South African Triage Scale (SATS) against admission as a reference standard and compare the sensitivity of triage using: (i) clinical discriminators; (ii) an age-appropriate physiological composite score; and (iii) a combination of both. METHODS: A prospective cohort study was undertaken validating the revised paediatric SATS against outcome markers of children at six emergency centres during a 2-month period in 2011. The primary outcome marker was the proportion of children admitted. Validity indicators including sensitivity (Se), specificity, positive predictive value and negative predictive value (NPV) were used to estimate the validity. Associated percentages for over-/under-triage were used to further assess practical application of the paediatric SATS. RESULTS: A total of 2 014 children were included. The percentage of hospital admissions increased with an increase in the level of urgency from 5% in the non-urgent patients to 73% in the emergency patients. The data demonstrated that sensitivity increased substantially when using the SATS, which is a combination of clinical discriminators and the Triage Early Warning Score (TEWS) (Se 91.0%, NPV 95.3%), compared with use of clinical discriminators in isolation (Se 57.1%, NPV 86.3%) or the TEWS in isolation (Se 75.6%, NPV 89.1%). CONCLUSION: The results of this study illustrate that the revised paediatric SATS is a safe and robust triage tool.


Asunto(s)
Pediatría/normas , Triaje/normas , Femenino , Humanos , Masculino , Estudios Prospectivos , Sudáfrica , Signos Vitales
10.
Spinal Cord ; 50(8): 595-8, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22584281

RESUMEN

STUDY DESIGN: A pilot prospective pre- and post-intervention study. OBJECTIVES: To determine whether a dynamic standing program using the Segway Personal Transporter results in any measurable physiological effects in individuals with spinal cord injury (SCI) using both qualitative and quantitative measures of spasticity, pain and fatigue. SETTING: International Collaboration of Repair Discoveries (ICORD) Research Centre, Vancouver, BC, Canada. METHODS: Eight individuals with SCI ASIA (American Spinal Injury Association) A-D, who could stand with or without the assistance of bracing or supports, participated in a 4-week dynamic standing program using a Segway (3 per week, 30-min sessions). The main outcome was spasticity as measured by the Modified Ashworth Scale (MAS). Secondary measures included the SCI-Spasticity Evaluation Tool, Pain Outcomes Questionnaire, and Fatigue Severity Scale. RESULTS: The dynamic standing sessions were associated with immediate improvements in spasticity (MAS) (P<0.001) and self-reported pain (P<0.05). Fatigue levels decreased, however this was not significant. There is little evidence to suggest that these beneficial outcomes may have lasting effects. CONCLUSIONS: Dynamic standing on the Segway may be effective for short-term spasticity reduction and decreased pain and fatigue. Future work should examine a larger sample size and help to propose mechanisms for potential reductions in spasticity.


Asunto(s)
Vehículos a Motor , Espasticidad Muscular/complicaciones , Espasticidad Muscular/fisiopatología , Dispositivos de Autoayuda , Traumatismos de la Médula Espinal/complicaciones , Adulto , Fatiga/complicaciones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor/complicaciones , Estudios Prospectivos , Autoinforme , Dispositivos de Autoayuda/efectos adversos , Índice de Severidad de la Enfermedad , Traumatismos de la Médula Espinal/rehabilitación , Encuestas y Cuestionarios
11.
Anim Genet ; 42(4): 386-94, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21749421

RESUMEN

Interferon regulatory factor 7 (IRF7), as a key regulator of type I interferon response, plays an important role during innate response against viral infection. Although well conserved across species, the structure of IRF7 and its function during parasite infection are not well documented in farm animals, such as the pig. To bridge this gap, we have determined the porcine IRF7 gene structure and identified two intronic single nucleotide polymorphisms (SNPs), SNP g.748G>C and SNP g.761A>G, in commercial pig breeds. The distribution of SNP g.761A>G in multiple breeds suggested that it was in Hardy-Weinberg equilibrium and allowed us to map it at the top of SSC2. We found that during Sarcocystis miescheriana infection, the G allele was associated with high lymphocyte levels (P < 0.02), reduced drop in platelet levels (P < 0.002) and IgG1-Th2-dominated response (P < 0.05). This suggests that the G allele was associated with better health and immunity of the host during Sarcocystis infection. Furthermore, we have also provided suggestive evidence that the G allele of SNPc.761A>G enhances the transactivation activity of IRF7, possibly by improving IRF7 transcript splicing of intron-3. These findings would suggest that IRF7, as a transcriptional regulator, is involved in the defence mechanism against a larger spectrum of pathogens, and in more host species, than initially anticipated.


Asunto(s)
Factor 7 Regulador del Interferón/genética , Fenotipo , Sarcocistosis/veterinaria , Transducción de Señal/inmunología , Sus scrofa/genética , Enfermedades de los Porcinos/genética , Enfermedades de los Porcinos/parasitología , Animales , Secuencia de Bases , Clonación Molecular , Cartilla de ADN/genética , Frecuencia de los Genes , Estudio de Asociación del Genoma Completo , Intrones/genética , Modelos Lineales , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sarcocistosis/genética , Análisis de Secuencia de ADN , Transducción de Señal/genética , Sus scrofa/inmunología , Porcinos
12.
Anim Genet ; 41(6): 619-29, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20477804

RESUMEN

Sequences from 20 amplicons representing nine different loci and 11369bp from the short arm of the pig Y chromosome were compared using pools of DNA from different European and Chinese breeds. A total of 33 polymorphic sites were identified, including five indels and 28 single nucleotide polymorphisms (SNPs). Three high frequency SNPs within the coding regions of SRY were further analysed across 889 males representing 25 European and 25 Asian breeds or Lines, plus a European Line of Meishan. Two haplotypes seen to be associated with 'European' or 'Chinese' origin in the initial SNP discovery phase were found to be the most common in their respective groups of breeds in a more detailed genotyping study. Two further SRY haplotypes are relatively rare. One was found exclusively within Tamworth, at low frequency in Retinto, and in three Chinese breeds (Huai, Sahwutou and Xiaomeishan). The other uncommon haplotype is found exclusively in Bamajiang, two further Chinese breeds (Hangjiang Black and Longling) and two European rare breeds (Mangalica and Linderödssvin), but appears based on comparison with other suids to represent an ancestral sequence.


Asunto(s)
Polimorfismo de Nucleótido Simple/genética , Análisis de Secuencia de ADN/métodos , Sus scrofa/genética , Cromosoma Y/genética , Animales , Cruzamiento , China , Cartilla de ADN/genética , Europa (Continente) , Haplotipos , Masculino , Técnicas de Amplificación de Ácido Nucleico , Filogenia , Proteína de la Región Y Determinante del Sexo/genética
14.
S. Afr. j. child health (Online) ; 1(4): 140-144, 2008.
Artículo en Inglés | AIM (África) | ID: biblio-1270373

RESUMEN

Objective: To describe the disease severity; clinical course and outcome of hospitalised HIV-infected children aged 6 months. Methods: A retrospective case review was completed at Red Cross Children's Hospital during mid-2006. The perinatal management; disease severity; and hospital outcome were analysed. In a sub-analysis; the disease profile and outcome of admitted children aged less than and greater than 6 months were compared over the latter 3 months of the study. Results: 75/121(43.86) of all HIV-infected children admitted over the study period were 6months were more likely to be receiving cotrimoxazole prophylaxis (65.4vs. 31.1; p=0.0008) and HAART (42.3vs. 6.7; p=0.00007) at the time of admission. Of those not on HAART; 27/30(90) had WHO stage 3 or 4 disease. In patient fatality in this group was 13.5Conclusions: Young children constitute a sizable proportion of the inpatient paediatric HIV workload. Comprehensive PMTCT interventions and earlier introduction of HAART may reduce morbidity; hospitalisation rates and mortality


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA , Niño , Infecciones por VIH/diagnóstico , Infecciones por VIH/prevención & control , Infecciones por VIH/terapia , Lactante
15.
Anim Genet ; 38(3): 222-6, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17459018

RESUMEN

Ear size and erectness are important conformation measurements in pigs. An F(2) population established by crossing European Large White (small, erect ears) with Chinese Meishan (large, flop ears) was used to study the genetic influence of the two ear traits for the first time. A linkage map incorporating 152 markers on 18 autosomal chromosomes was utilised in a genome scan for QTL. Significant QTL were found on SSC1, 5, 7, 9 and 12 for the two traits. The QTL on SSC5 and SSC7 had major effects and were significant at the genome-wide level (P < 0.01). The QTL on SSC1 for ear erectness also had a major effect and was genome-wide significant (P < 0.01). The 95% confidence interval (CI) of the ear size QTL on SSC5 spanned only 4 cM. The QTL on SSC7 for the two ear traits each had a CI of <20 cM, and their positions overlapped with those of the major QTL affecting subcutaneous fat depths on the same chromosome. This study provides insights on the complex genetic influences underlying pig ear traits and will facilitate positional candidate gene analysis to identify causative DNA variants.


Asunto(s)
Oído/anatomía & histología , Sitios de Carácter Cuantitativo , Sus scrofa/genética , Animales , Mapeo Cromosómico , Cruzamientos Genéticos , Oído/fisiología , Genómica/métodos , Tamaño de los Órganos
16.
Reproduction ; 123(4): 507-15, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11914113

RESUMEN

Embryo transfer and pregnancy maintenance strategies in pigs were evaluated with reference to situations in which limited numbers of viable embryos or micromanipulated embryos are available, such as pig cloning. Development of embryos with compromised zona pellucida was compared with development of embryos with intact zona pellucida. Micromanipulation had no effect on blastocyst production rates after development in vivo or in vitro, but development in vivo improved the number of embryos reaching the blastocyst stage. Transfer of embryos with compromised zona pellucida resulted in live piglets. Several hormone treatments to maintain pregnancy were tested in a model in which three embryos were transferred into unmated recipient gilts, compared with transfer of three embryos into mated recipients. None of the hormonal treatments resulted in pregnancy rates of more than 25% at term and no more than 9% of transferred embryos survived, in comparison with 50% of the mated recipients successfully carrying 25% of transferred embryos. Lastly, the developmental potential of parthenogenetic embryos was assessed and 62% of transferred embryos resulted in pregnancies, none of which continued beyond day 55 of gestation. After co-transfer of three fertilized embryos with 55-60 parthenogenetic embryos into each of six recipients, two live piglets were delivered. The results from the present study indicate that transfer of zona pellucida compromised embryos can yield litters of normal piglets. In addition, it was demonstrated in a model system involving the transfer of three fertilized embryos into mature gilts that hormonal pregnancy maintenance strategies support a low proportion of embryos to term. Lastly, the present study shows for the first time a comparably effective but novel alternative for pregnancy maintenance in the pig involving the co-transfer of parthenote embryos.


Asunto(s)
Clonación de Organismos , Transferencia de Embrión/veterinaria , Desarrollo Embrionario y Fetal/fisiología , Porcinos , Animales , Técnicas de Cultivo de Célula , Femenino , Embarazo , Zona Pelúcida/fisiología
17.
Heart ; 82(6): e9, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10573505

RESUMEN

OBJECTIVE: To investigate the link between changes in level of physical activity and the pattern of heart rate variability during long term ambulatory monitoring. DESIGN: Heart rate variability was measured simultaneously with a quantitative indicator of muscle activity by electromyography (EMG) in five men and five women while they did activities typical of daily life or while they rested for 2-3 hours. Spectral and cross spectral analyses were performed on both variables with standard fast Fourier transform. RESULTS: There was a marked reduction in spectral power in the ultra low frequency band (< 0.003 Hz) on going from active to rest conditions for both heart rate variability (men 6187 (1801) v 410 (89) ms(2)/Hz; women 4056 (1161) v 2094 (801), mean (SEM); p < 0.01) and EMG (p < 0.001). Cross spectral analysis showed a strong positive gain between the EMG and heart rate variability signal that was virtually eliminated in the resting condition (p < 0.01). A sex-by-condition effect (p = 0.06) was noted with a reduction in total spectral power for heart rate variability during rest in men, while it increased slightly in women. CONCLUSIONS: There is a quantitative link between muscle activation and heart rate variability in the lowest frequency band. Voluntary restriction of physical activity in healthy young subjects caused marked reduction in spectral power in the lowest frequency band which is often used to assess patient prognosis. The findings strongly suggest that studies of ambulatory heart rate variability should always include an indication of physical activity patterns.


Asunto(s)
Ejercicio Físico/fisiología , Frecuencia Cardíaca/fisiología , Adulto , Electromiografía , Femenino , Humanos , Masculino , Factores Sexuales
18.
Anim Genet ; 29(6): 415-24, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9883502

RESUMEN

A F2 population derived from a cross between European Large White and Chinese Meishan pigs was established in order to study the genetic basis of breed differences for growth and fat traits. Chromosome 4 was chosen for initial study as previous work had revealed quantitative trait loci (QTLs) on this chromosome affected growth and fat traits in a Wild Boar x Large White cross. Individuals in the F2 population were typed for nine markers spanning a region of approximately 124 CM. We found evidence for QTLs affecting growth between weaning and the end of test (additive effect: 43.4 g/day) and fat depth measured in the mid-back position (additive effect: 1.82 mm). There was no evidence of interactions between the QTLs and sex, grandparents or F1 sires, suggesting that the detected QTLs were fixed for alternative alleles in the Meishan and Large White breeds. Comparison of locations suggests that these QTLs could be the same as those found in the Wild Boar x Large White cross.


Asunto(s)
Cromosomas , Carácter Cuantitativo Heredable , Porcinos/genética , Animales , Mapeo Cromosómico/veterinaria , Femenino , Genotipo , Masculino , Fenotipo
20.
J Appl Bacteriol ; 61(3): 201-8, 1986 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-3781936

RESUMEN

Streptococcus bovis H13/1 was grown anaerobically at pHs between 5.0 and 6.5 in a glucose-limited chemostat at a dilution rate of 0.05/h. The growth yield and the production of acetate, ethanol and formate decreased at pHs less than 6.5 whereas the production of lactate increased at the lower pH values. When a culture was subjected to sequential pH changes, growth yield and fermentation products were influenced not only by the pH existing in the culture medium but also by the metabolic activity of the cells at the preceding pHs in the sequence. The results are discussed in relation to the mechanisms available for the maintenance of pH homeostasis and for the metabolic control of fermentation pathways in Strep. bovis.


Asunto(s)
Streptococcus/crecimiento & desarrollo , Medios de Cultivo , Metabolismo Energético , Fermentación , Glucosa/metabolismo , Concentración de Iones de Hidrógeno , Streptococcus/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA