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1.
JDR Clin Trans Res ; : 23800844231169642, 2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38279706

RESUMO

BACKGROUND: People with alcohol dependence (AD) frequently experience oral health problems, but their dental attendance is poor, with limited evidence to the reasons why from their perspective. OBJECTIVE: To explore perceived barriers, motivators, and facilitators to accessing primary dental care in people with AD. METHODS: Qualitative study consisting of remote one-to-one and group semistructured interviews with a convenience sample of adults with lived experience of AD in northern England. Data were audio-recorded, transcribed, and coded. A reflexive thematic analysis method was used; use of COM-B model informed data interpretation. RESULTS: Twenty adults with lived experience of AD participated in 18 one-to-one interviews and 1 group interview (of 3 participants). Barriers to access were fear and physical, social, and environmental factors (physical effects of AD, financial barriers, nonprioritization of oral health). Motivators to access were pain and prioritization of oral health. Facilitators to access were patterns of alcohol use (i.e., sobriety) and dental service provision within recovery services. CONCLUSIONS: Fear of "the dentist" is a major barrier to accessing dental care, and pain is the primary motivator, among people with AD, although neither are unique to this population. Fear and physical, social, and environmental barriers to access contribute to problem-oriented attendance, which negatively affect oral health outcomes. Opportunity to facilitate attendance increases when a person is in remission from AD through their physical capabilities improving. Increasing capability and opportunity can influence attendance beyond the automatic motivation of pain. Provision of dental care within recovery services could facilitate access to care. Understanding the "web of causation" is key to developing any intervention to improve dental access in people with AD. Further research is needed from the perspective of other adult populations with lived experience of AD, as well as of dental professionals, to gain deeper insight into barriers, facilitators, and possible solutions. KNOWLEDGE TRANSFER STATEMENT: The results of this study can help dental professionals understand factors affecting access to primary care in people with alcohol dependence to provide knowledge that may reduce stigma surrounding the disease. Results also demonstrate areas for intervention development for public policy.

2.
J Laryngol Otol ; 135(10): 887-891, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34372958

RESUMO

OBJECTIVE: Visual-vestibular mismatch patients experience persistent postural and perceptual dizziness. Previous studies have shown the benefit of vestibular rehabilitation for visual desensitisation using gaze stabilisation exercises and optokinetic stimulation. This study assessed the benefit of customised vestibular rehabilitation with visual desensitisation and virtual reality based therapy rehabilitation in the management of patients with persistent postural-perceptual dizziness. METHODS: This retrospective study included 100 patients with Situational Characteristic Questionnaire scores of more than 0.9. All patients received virtual reality based therapy along with usual vestibular rehabilitation using gaze stabilisation exercises with a plain background followed by graded visual stimulation and optokinetic digital video disc stimulation. Patients' symptoms were assessed before and after vestibular rehabilitation using the Situational Characteristic Questionnaire, Generalised Anxiety Disorder Assessment-7, Nijmegen Questionnaire and Dizziness Handicap Inventory. RESULTS: There were statistically significant improvements in Situational Characteristic Questionnaire scores, Nijmegen Questionnaire scores and Dizziness Handicap Inventory total score. However, there was a statistically insignificant difference in Generalised Anxiety Disorder Assessment-7 scores. There was a significant positive correlation between post-rehabilitation Situational Characteristic Questionnaire scores and other questionnaire results. CONCLUSION: Incorporating virtual reality based therapy with customised vestibular rehabilitation exercises results in significant improvement in persistent postural-perceptual dizziness related symptoms.


Assuntos
Vertigem Posicional Paroxística Benigna/diagnóstico , Vertigem Posicional Paroxística Benigna/reabilitação , Doenças Vestibulares/fisiopatologia , Realidade Virtual , Adulto , Vertigem Posicional Paroxística Benigna/psicologia , Terapia por Exercício/métodos , Feminino , Fixação Ocular/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Nistagmo Optocinético/fisiologia , Estimulação Luminosa/métodos , Propriocepção/fisiologia , Estudos Retrospectivos , Autorrelato/estatística & dados numéricos , Inquéritos e Questionários
4.
J Laryngol Otol ; 132(6): 550-553, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30019667

RESUMO

BACKGROUND: Visual vertigo is defined as a condition in which there is worsening or triggering of vestibular symptoms in certain visual environments. Previous studies have associated visual vertigo with an increased prevalence of underlying white matter lesions on brain imaging. METHOD: This study evaluated the magnetic resonance imaging scans of the brain from a cohort of patients with visual vertigo, and compared the outcomes to an age- and gender-matched group of healthy volunteers.Results and conclusionWhite matter lesions were observed in 17.9 per cent of the patient group and in 16.3 per cent of the control group. The prevalence of white matter lesions in the patient group was not too different to that expected based on age.


Assuntos
Encéfalo/diagnóstico por imagem , Leucoencefalopatias/diagnóstico por imagem , Vertigem/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Vertigem Posicional Paroxística Benigna/diagnóstico por imagem , Vertigem Posicional Paroxística Benigna/epidemiologia , Vertigem Posicional Paroxística Benigna/fisiopatologia , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Humanos , Leucoencefalopatias/epidemiologia , Imageamento por Ressonância Magnética , Masculino , Doença de Meniere/diagnóstico por imagem , Doença de Meniere/epidemiologia , Doença de Meniere/fisiopatologia , Pessoa de Meia-Idade , Transtornos de Enxaqueca/diagnóstico por imagem , Transtornos de Enxaqueca/epidemiologia , Transtornos de Enxaqueca/fisiopatologia , Prevalência , Índice de Gravidade de Doença , Inquéritos e Questionários , Vertigem/epidemiologia , Vertigem/fisiopatologia , Neuronite Vestibular/diagnóstico por imagem , Neuronite Vestibular/epidemiologia , Neuronite Vestibular/fisiopatologia , Percepção Visual , Adulto Jovem
5.
Br Dent J ; 228(12): 906, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32591686

Assuntos
Helianthus
6.
Invest Ophthalmol Vis Sci ; 31(8): 1427-32, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1974892

RESUMO

Retinal degeneration is inherited in an autosomal recessive pattern in the retinal degeneration (rd) mouse. The defective gene for this disease has been mapped to mouse chromosome 5 between the well-defined (anchor) genes Afp and Gus. We recently cloned a putative rd cDNA, zr.408, using a strategy based on subtractive and differential hybridization. zr.408 was shown to hybridize to a larger message from rd/rd mice than from normal mice in Northern blots; was mapped to mouse chromosome 5; and was used to detect restriction fragment length polymorphisms (RFLPs) between rd/rd and +/+ DNA in genomic Southern blots. In order to obtain further evidence that zr.408 does in fact correspond to the rd gene, we used two methods to position zr.408 on chromosome 5. Analysis of an intersubspecific backcross localized the sequences corresponding to zr.408 between the genes Afp and Gus, as expected for rd. The second approach involved an interspecific backcross using C57BL/6J-rd/rd mice congenic for the normal allele of rd, which was derived from the wild mouse, Mus spretus; the results of this study showed that zr.408 is at or near the rd locus. These two studies add evidence to the existing data, which suggest that zr.408 is the correspondent of the rd gene.


Assuntos
Mapeamento Cromossômico , DNA/genética , Degeneração Retiniana/genética , Animais , Southern Blotting , Cruzamentos Genéticos , Sondas de DNA , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hibridização de Ácido Nucleico , Polimorfismo de Fragmento de Restrição
7.
J Appl Physiol (1985) ; 58(1): 18-26, 1985 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3968008

RESUMO

A model of the pulmonary airways was used to study three single-breath indices of gas mixing, dead space (VD), slope of the alveolar plateau, and alveolar mixing inefficiency (AMI). In the model, discrete elements of airway volume were represented by nodes. Using a finite difference technique the differential equation for simultaneous convection and diffusion was solved for the nodal network. Conducting airways and respiratory bronchioles were modeled symmetrically, but alveolar ducts asymmetrically, permitting interaction between convection and diffusion. VD, alveolar slope, and AMI increased with increasing flow. Similar trends were seen with inspired volume, although slope decreased at high inspired volumes with constant flow. VD was affected most by inspiratory flow and AMI and alveolar slope by expiratory time. VD fell approximately exponentially with time of breath holding. Eight different breathing patterns were compared. They had a small effect on alveolar slope and AMI and a greater effect on VD. The model shows how series and parallel inhomogeneity occur together and interact in asymmetrical systems: the old argument as to which is the more important should be abandoned.


Assuntos
Modelos Biológicos , Alvéolos Pulmonares/anatomia & histologia , Respiração , Gases , Espaço Morto Respiratório , Fatores de Tempo
8.
Comput Methods Programs Biomed ; 44(1): 31-5, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7988109

RESUMO

On-going work relating to the development of advanced information management systems for intensive care is described. The objective of this paper is to outline the complex issues that need to be addressed when developing such systems. This work is in part sponsored by the Commission of the European Communities under the AIM TANIT project, and an overview of its approach is given. Data protection, security and confidentiality aspects are emphasised, together with the need to balance data availability with the need for security.


Assuntos
Segurança Computacional , Sistemas de Gerenciamento de Base de Dados , Sistemas de Informação Hospitalar/normas , Unidades de Terapia Intensiva , Sistemas Computacionais , Confidencialidade , Europa (Continente) , União Europeia , Sistemas Computadorizados de Registros Médicos , Projetos Piloto , Interface Usuário-Computador
9.
Comput Methods Programs Biomed ; 45(1-2): 159-64, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7889753

RESUMO

On-going work relating to the development of advanced telematics systems for Critical Care environments is described. This work is in part sponsored by the Commission of European Communities under the AIM TANIT project. Two example departments have been selected for piloting in the project: Intensive Care and Anaesthesia. The objective of this paper is to outline the complex issues that need to be addressed when developing such systems.


Assuntos
Serviço Hospitalar de Anestesia , Redes de Comunicação de Computadores , Sistemas de Informação Hospitalar , Unidades de Terapia Intensiva , Serviço Hospitalar de Anestesia/organização & administração , Segurança Computacional , Confidencialidade , Coleta de Dados/normas , Europa (Continente) , Sistemas de Informação Hospitalar/normas , Humanos , Unidades de Terapia Intensiva/organização & administração , Sistemas Computadorizados de Registros Médicos , Projetos Piloto , Integração de Sistemas
10.
Stud Health Technol Inform ; 16: 157-66, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-10163710

RESUMO

The paper discusses the potential roles for protocols of care within critical care environments from the perspective of providing real-time support for their application. The discussion is based around a conceptual model of care in critical care environments. This model has been developed in the wider context of developing information technology systems to support clinical care in critical care environments. The conceptual model of care is a three layer model which demonstrates both the hierarchical and temporal aspects of the care delivered to patients. It is proposed that if the value of protocols of care is to be realised in critical care environments then they must be seamlessly integrated into the routine data management associated with the care of patients. In order to demonstrate this and to evaluate the utility of this concept in the clinical environment, the systems from the AIM TANIT (Telematics in Anaesthesia and Intensive Therapy) project have been used as prototype platforms. The application of the concepts developed are described in two critical care environments: the anaesthesia department and the intensive care unit. Problems in using protocols of care in intensive care units suggest that integrating these with a problem solving methodology to create an integrated care plan may be a more appropriate approach to patient management.


Assuntos
Cuidados Críticos , Técnicas de Apoio para a Decisão , Aplicações da Informática Médica , Guias de Prática Clínica como Assunto , Serviço Hospitalar de Anestesia , Sistemas Computacionais , Humanos , Sistemas Computadorizados de Registros Médicos , Planejamento de Assistência ao Paciente , Equipe de Assistência ao Paciente
11.
Exp Eye Res ; 45(4): 467-80, 1987 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2828090

RESUMO

A lesion in cGMP metabolism has been hypothesized to cause retinal degeneration in rd mice. Available cloned cDNAs coding for proteins involved in the cGMP cascade have been used to compare the corresponding retinal RNAs in the degenerative (rd/rd) mouse at 8-11 days with those in the 8-11-day-old morphologically normal (rd/+) and adult normal (+/+) mice. Northern analysis of these RNAs hybridized to the specific 32P-labeled cDNA probes for G-protein, 48,000 MW protein and opsin, indicates in each case, that the corresponding transcripts are made in the rd/rd mouse retina and that there are no overt differences in their size compared to the transcripts hybridized in the rd/+ or +/+ mouse retinas. Although a defect in the phosphorylation of opsin has been described in rd mice, no difference was found in the transcripts hybridized by a cDNA probe corresponding to the region of the opsin molecule on which phosphorylation occurs. We do find, however, that labeled bovine-derived opsin cDNA recognizes five different RNA size classes in mouse and bovine retinas. Control experiments were performed to confirm that the RNA hybridized by opsin cDNA was not due to non-specific hybridization to unrelated RNAs.


Assuntos
GMP Cíclico/biossíntese , Proteínas Heterotriméricas de Ligação ao GTP , RNA Mensageiro/metabolismo , Degeneração Retiniana/metabolismo , Animais , Antígenos/metabolismo , Arrestina , DNA Recombinante , Eletroforese em Gel de Ágar , Proteínas do Olho/biossíntese , Proteínas do Olho/metabolismo , Subunidades alfa de Proteínas de Ligação ao GTP , Proteínas de Ligação ao GTP/biossíntese , Camundongos , Camundongos Mutantes , Peso Molecular , Hibridização de Ácido Nucleico , Retina/metabolismo , Pigmentos da Retina/biossíntese , Opsinas de Bastonetes , Transcrição Gênica , Transducina
12.
Clin Obstet Gynecol ; 23(2): 549-57, 1980 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7398165

RESUMO

For 300 years the use of midforceps by skilled obstetricians was the safest alternative to the prolonged, arrested second stage of labor. In the past 30 years the use of oxytocin augmentation for dysfunctional labor, the declining morbidity of cesarean section, and the greater skill of obstetricians in performing the abdominal rather than the vaginal operation have established cesarean section as the less hazardous method for dealing with most cases of abnormal second stage of labor. To prove conclusively that cesarean section is the safest method of delivery in all such cases a prospective, randomized study must be done.


Assuntos
Extração Obstétrica , Peso ao Nascer , Cesárea , Feminino , Humanos , Recém-Nascido , Segunda Fase do Trabalho de Parto , Gravidez , Fatores de Tempo
13.
Exp Eye Res ; 47(3): 369-90, 1988 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2846333

RESUMO

Retinal degeneration in rd mice is manifested during the most rapid period of postnatal photoreceptor differentiation and is hypothesized to be caused by a lesion in cGMP metabolism. We have studied the sequence of developmental expression of three proteins involved in the cGMP cascade and the mRNAs from which they are translated, in rd and control mouse retinas. Slot blot analysis of retinal RNAs indicates that the mRNAs coding for opsin, the alpha, beta and gamma subunits of G-protein and 48-kDa protein each has the same time for onset of expression in normal and diseased retinas. G beta and 48-kDa protein mRNAs are already detectable at birth, opsin mRNA appears by postnatal day 5 (P5), G gamma mRNA at P6 and G alpha mRNA by P8. The levels of all these mRNAs decrease in the diseased retinas after P11-P12, correlating with the reduction in photoreceptor cell number that characterizes the rd disease. Immunocytochemistry indicates that the 48-kDa protein is present at birth, G gamma and opsin are detectable at P4 and G alpha at P7. After P7, opsin and G-protein immunoreactivity are localized throughout the photoreceptor cell in the rd retinas but they are found only in the outer segment in control retinas. The 48-kDa protein immunoreactivity, which is observed in the whole photoreceptor layer both in rd and control retinas throughout development, is the only one of all immunoreactivities analysed that remains at 2 months of age in the rd retina and is probably localized in cones. However, at 6 months of age, 48-kDa protein immunoreactive cells are no longer present in the rd retina. We have also investigated whether there is a daily rhythm for the levels of mRNA present at different times during the light/dark periods in developing rd/rd and rd/+ retinas and in adult normal (+/+) retinas. We find that the levels of each mRNA analysed appear to cycle in the +/+ adult retina, with the greatest amount of opsin and the three subunits of G-protein mRNAs occurring just before light onset and the greatest amount of 48-kDa protein mRNA occurring just before lights off. Cycling in the developing diseased or control retinas (P0-P12) is not observed and may be masked by the pronounced cell growth that occurs during this period.


Assuntos
Proteínas do Olho/metabolismo , Proteínas Heterotriméricas de Ligação ao GTP , RNA Mensageiro/biossíntese , Degeneração Retiniana/metabolismo , Envelhecimento/metabolismo , Animais , Ritmo Circadiano , GMP Cíclico/biossíntese , Subunidades alfa de Proteínas de Ligação ao GTP , Proteínas de Ligação ao GTP/metabolismo , Imuno-Histoquímica , Luz , Camundongos , Camundongos Endogâmicos C57BL , Retina/metabolismo , Opsinas de Bastonetes , Transducina
14.
Am J Obstet Gynecol ; 137(7): 791-6, 1980 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-7405969

RESUMO

Continuous monitoring tracings of fetal heart rate in 61 infants with birth weights of 1,500 grams or less were analyzed and related to newborn outcome. Reassuring heart rate patterns or good baseline variability correlated well with a normal unbilical artery pH. Fetal heart rate patterns and baseline variability were not related in a predictive way to central nervous system hemorrhage, respiratory distress syndrome, or neonatal death. Early intervention and operative delivery in cases demonstrating abnormal fetal heart rate patterns may have influenced the outcome in these infants. Fetal heart rate patterns can play an important role in the intrapartum assessment of the condition of the very-low-birth-weight infant and may be used to select those infants requiring prompt operative intervention and vigorous neonatal resuscitation.


Assuntos
Coração Fetal/fisiologia , Monitorização Fetal , Frequência Cardíaca , Recém-Nascido de Baixo Peso , Recém-Nascido Prematuro , Equilíbrio Ácido-Base , Índice de Apgar , Hemorragia Cerebral/diagnóstico , Feminino , Sangue Fetal , Humanos , Doença da Membrana Hialina/diagnóstico , Concentração de Íons de Hidrogênio , Mortalidade Infantil , Recém-Nascido , Doenças do Recém-Nascido/diagnóstico , Gravidez
15.
Dev Med Child Neurol ; 36(3): 241-52, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8138073

RESUMO

The most appropriate posture in which to support the person with severe disability and diverse symptoms as a result of complex pathology remains more a matter of opinion than the result of research. This work reviews some of the studies which have attempted to identify definitive criteria for seating in such cases. Factors relating to measurement and conditions which threaten to invalidate the results of research in this field are highlighted. A description of the Seating and Mobility (SAM) system is given, together with a report of the monitoring of nine children with cerebral palsy using the system for a period of three years. The difficulties inherent in this work are noted and questions for future considerations are raised.


Assuntos
Pessoas com Deficiência/reabilitação , Medicina Física e Reabilitação/instrumentação , Postura , Atividades Cotidianas , Braço/fisiologia , Paralisia Cerebral/reabilitação , Criança , Desenvolvimento Infantil , Pré-Escolar , Desenho de Equipamento , Feminino , Humanos , Masculino , Sialorreia , Decúbito Dorsal
16.
Cell Mol Neurobiol ; 11(6): 611-22, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1723658

RESUMO

1. The neurons of the retina have electrical properties that are different from those of most of the other neurons of the central nervous system. To identify the voltage-gated ion channels found in the retina, we screened mouse retinal cDNA libraries with oligonucleotide probes homologous to the mammalian K+ channel MBK1 (Kv1.1) and ligated two partial clones to produce a full-length clone with no significant differences from MBK1. 2. Expression of MBK1 mRNA was determined by RNAse protection. MBK1 mRNA was detected in retinal RNA and was also detected in brain, liver, and heart RNAs. 3. We transcribed the full-length clone, injected it into oocytes of Xenopus laevis, and measured the membrane currents 2 to 6 days later. Depolarization from a holding voltage of -90mV induced a slowly activated outward current with a peak value as large as 20 microA. The current inactivated very slowly with a single exponential time course [mean time constant, 6.5 +/- 0.4 sec (SEM) for activation voltage of -10mV]. 4. The outward current was reduced to half-maximal by 0.42 mM tetraethylammonium, 1.1 mM 4-aminopyridine, and 3.2 mM Ba2+ but was not significantly attenuated by Co2+ (1 mM). 5. The reversal potential (measured with tail currents) changed by 53mV per decade change of [K+] from 1 to 77 mM. 6. The voltage for half-maximal activation of the conductance was -26.6mV (+/- 1.7mV), and the voltage required for an e-fold increase in conductance was 6.9mV (+/- 0.5mV). 7. Thus, the mRNA for MBK1 found in the mouse retina causes the expression of a voltage-dependent K+ current which has properties suitable for may retinal neurons.


Assuntos
Canais de Potássio/genética , Retina/fisiologia , Animais , Sequência de Bases , DNA/genética , Expressão Gênica , Biblioteca Genômica , Potenciais da Membrana , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Sondas de Oligonucleotídeos , Oócitos/fisiologia , Canais de Potássio/metabolismo , Canais de Potássio/fisiologia , RNA/análise , RNA Mensageiro/genética , Retina/metabolismo , Xenopus laevis
17.
Proc Natl Acad Sci U S A ; 86(24): 9722-6, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2481314

RESUMO

The inherited retinal degeneration of the rd mouse results in the exclusive loss of one cell type, the photoreceptors. We took advantage of this visual-cell loss to devise a strategy for the isolation of photoreceptor-specific cDNAs based on the use of subtractive and differential hybridizations. The resulting pool of photoreceptor-specific cDNAs was screened for a candidate cDNA for the rd gene, and a putative rd cDNA that maps to mouse chromosome 5, the chromosome to which the rd gene has been assigned, was identified. On Northern blots the candidate rd cDNA hybridizes a 3.3-kilobase RNA species from 9- to 11-day-old developing normal retina and, much more faintly, a 3.6-kb RNA species from age-matched rd retina. The 0.3-kilobase difference in the size of the mRNAs hybridized suggests that a structural alteration in the gene corresponding to the candidate rd cDNA has occurred in the rd mouse. This was further supported by the detection of polymorphisms between rd/rd and +/+ mouse genomic DNA after digestion with restriction endonucleases and probing with the candidate rd cDNA. Expression of mRNAs hybridized by the candidate rd cDNA is detected in normal and diseased retinas at postnatal day 1 but the signal intensity is considerably lower in the rd retina. To our knowledge, this is the earliest molecular defect reported in the rd retina that is observed prior to any phenotypic signs of photoreceptor degeneration.


Assuntos
DNA/genética , Genes , Degeneração Retiniana/genética , Animais , Southern Blotting , Mapeamento Cromossômico , Clonagem Molecular , Cricetinae , Cricetulus , DNA/isolamento & purificação , Sondas de DNA , Biblioteca Gênica , Células Híbridas/citologia , Camundongos , Camundongos Mutantes , Células Fotorreceptoras/metabolismo , RNA/genética , RNA/isolamento & purificação , Retina/análise , Retina/metabolismo
18.
Am J Obstet Gynecol ; 135(7): 965-73, 1979 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-507136

RESUMO

A retrospective study of 460 single-gestation infants in breech position was conducted at the University of Colorado Medical Center to assess the impact of a policy for the selection of cases for vaginal delivery. Among infants weighing more than 2,500 grams, there was an increase in the cesarean section rate from 13% to 54%, with an associated increase in maternal morbidity from 7% to 15%. This occurred with no significant reduction in adverse perinatal outcome. However, a case-by-case review suggests that more frequent and timely cesarean sections would have further reduced perinatal morbidity and deaths among term infants. Among the infants weighing 2,500 grams or less there was an increase in cesarean births from 5% to 55% following the introduction of the strict criteria for vaginal delivery. Among the infants weighing 1,501 to 2,500 grams there was no significant difference in survival between the cesarean and vaginally delivered patients. Although infants weighing 501 to 1,500 grams delivered by cesarean section survived more frequently than did those delivered vaginally, the differences in perinatal deaths may have been due to a higher birth weight in the cesarean-delivered infants or an over-all improvement in neonatal intensive care for infants of very low birth weight.


Assuntos
Apresentação Pélvica , Parto Obstétrico/métodos , Morte Fetal/epidemiologia , Mortalidade Infantil , Recém-Nascido , Apresentação no Trabalho de Parto , Complicações do Trabalho de Parto/epidemiologia , Índice de Apgar , Peso ao Nascer , Cesárea , Colorado , Cuidados Críticos , Feminino , Idade Gestacional , Humanos , Recém-Nascido de Baixo Peso , Gravidez
19.
Artigo em Inglês | MEDLINE | ID: mdl-7068477

RESUMO

An asymmetrical model of the human pulmonary acinus is described, in which elements of volume are represented by nodes joined by conductors permitting convective flow and molecular diffusion. The method of analysis permits simultaneous convection, diffusion, and dimensional change in any direction and requires only simple boundary conditions. Inspiration of O2 into a resident gas of 79% N2 followed by expiration was simulated at two flows. On expiration the slope of the alveolar plateau was 1.7%, and the alveolar N2 mixing efficiency was 97.0%. A symmetrical but otherwise similar model gave a slope of zero and a mixing efficiency of 99.9%. The patterns of gas concentration within the asymmetrical acinus during the respiratory cycle confirm and extend previous observations on the interactions between simultaneous convection and diffusion in asymmetrical structures (16, 21, 22). Even though these in combination within alveolar duct asymmetry can account for the slope of the alveolar plateau, they are insufficient to account for the failure of complete gas mixing found in normal subjects.


Assuntos
Alvéolos Pulmonares/fisiologia , Respiração , Humanos , Modelos Biológicos , Nitrogênio , Oxigênio , Capacidade de Difusão Pulmonar
20.
Proc Natl Acad Sci U S A ; 90(7): 2955-9, 1993 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-8385352

RESUMO

Retinal degeneration in the rd mouse is inherited as an autosomal recessive trait and is caused by a defect in the gene encoding the beta subunit of cGMP phosphodiesterase. Recently, a close genetic association of the rd gene with an endogenous xenotropic murine leukemia virus (Xmv-28) was established by linkage analysis using recombinant inbred strains of mice. In this study, genomic DNA mapping and sequence analyses clarify the position of the proviral sequences in relation to the rd gene. We find that the Xmv-28 provirus is integrated into intron I of the rd gene 1511 bp downstream of the exon-intron boundary. The transcriptional orientation of the provirus is opposite to that of the gene for the beta subunit of cGMP phosphodiesterase. Reverse transcription-PCR demonstrates that the integrated Xmv-28 sequences are transcribed in the retina. The provirus is present in every strain of rd mouse tested.


Assuntos
3',5'-GMP Cíclico Fosfodiesterases/genética , Genes , Diester Fosfórico Hidrolases , Retroviridae/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular/métodos , Cruzamentos Genéticos , Nucleotídeo Cíclico Fosfodiesterase do Tipo 6 , DNA/genética , Feminino , Íntrons , Substâncias Macromoleculares , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Reação em Cadeia da Polimerase/métodos , Mapeamento por Restrição , Retroviridae/isolamento & purificação , Transcrição Gênica
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