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OBJECTIVES: The cost-of-living crisis is a public health threat; however, the effects of the rising cost of living were not a policy priority for integrated care systems (ICSs) in early 2022. At the request of ICS leaders, the National Health Service (NHS) Confederation created an online cost-of-living hub in October 2022 to raise awareness of the consequences of the rising cost of living among ICS policymakers and support systems in mitigating these effects. This study aims to investigate the impact of this hub. STUDY DESIGN: Mixed methods. METHODS: To quantify hub utilisation, the hub viewing figures collected by the NHS Confederation website were analysed. A thematic analysis was performed to characterise how cost-of-living features in integrated care strategies, and the results compared to information published on the hub. RESULTS: The pages that comprise the hub were well engaged with, having between 2736 and 6161 views. Alongside this, the impacts of the rising cost of living feature extensively in integrated care strategies, being discussed in 32 out of 37 strategies across four contexts: health, communities, economic, and environmental. The significant majority of subthemes reflect points made by the hub. CONCLUSION: These results suggest the hub may have raised awareness about the impacts of-and possible responses to-the cost-of-living crisis among ICS policymakers. This may act as an impetus and guide for future public health interventions using policy and practice hubs. Furthermore, the discussion of cost-of-living across a range of contexts implies ICSs are engendering a collaborative, system-wide approach to tackling complex local issues.
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Prestación Integrada de Atención de Salud , Política de Salud , Medicina Estatal , Humanos , Prestación Integrada de Atención de Salud/economía , Medicina Estatal/economía , Reino UnidoRESUMEN
The primary aim of this research was to investigate potential differences of breast tumor morphologies across African American and Caucasian racial groups by utilizing machine learning (ML) and artificial intelligence (AI) methods. While breast cancer disparities can partially be attributed to social determinants of health, tumor biology also contributes to survival outcomes. The rate of breast tumor growth is largely dependent on the extracellular matrix (ECM). Current research suggests the cellular components of the ECM may vary among racial and ethnic populations, and this may contribute to the incidence of cancer in African Americans. We utilized a supervised AI method to evaluate morphological differences between African American and Caucasian breast cancer tumors. Images used for analysis were downloaded from the Cancer Genome Atlas (TCGA) biorepository stored in the NIH Genomic Data Commons (GDC) data portal. We designed an ML classifier using the AlexNet model provided in PyTorch's torchvision package. The model was pre-trained and adapted via transfer learning resulting in a classification accuracy of 92.1% when using our breast cancer tumor image database split into 80% of training set and 20% of testing set. We interpreted the results of the AlexNet and ResNet50 models using LIME and saliency mapping as the explainers. Based on the images from our bi-racial testing set, this study confirmed significant variations of tumor and ECM regions in the different racial groups evaluated. Based on these findings, further analysis and characterization may provide new insight into disparities associated with the incidence of breast cancer.
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BACKGROUND: Fundoscopy outside ophthalmology is in decline, and the technical demands of the traditional direct ophthalmoscope examination are likely contributing. Alternative fundoscopy technologies are increasingly available, yet valid comparisons between fundoscopy technologies are lacking. We aimed to assess medical students' perceptions of usefulness and ease of use of traditional and contemporary fundus-viewing technologies including smartphone fundoscopy. METHODS: One hundred forty-six second-year medical students participated in a cross-sectional, randomised, cross-over study of fundoscopy methods. Medical students completed small group training sessions using six current fundoscopy technologies including: a non-mydriatic fundus camera; two types of direct fundoscopy; and three types of smartphone fundoscopy. A novel survey of perceived usefulness and ease of use was then completed by students. RESULTS: Repeated-measures ANOVA found students rated both the perceived usefulness (p< 0.001) and ease of use (p< 0.001) of smartphone fundoscopy significantly higher than both the non-mydriatic camera and direct fundoscopy. CONCLUSIONS: Smartphone fundoscopy was found to be significantly more useful and easier to use than other modalities. Educators should optimise student access to novel fundoscopy technologies such as smartphone fundoscopy which may mitigate the technical challenges of fundoscopy and reinvigorate use of this valuable clinical examination.
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Estudiantes de Medicina , Estudios Cruzados , Estudios Transversales , Fondo de Ojo , Humanos , Oftalmoscopía , Teléfono InteligenteRESUMEN
Access to oral health care has been a topic of concern among dental and community health professionals in the United States for some time. The American Dental Association is piloting a new program aimed at expanding the current dental health workforce and alleviating some of the problems associated with access to care. This paper explores the potential benefits of the community dental health coordinator program while examining some of the lessons learned in its initial implementation in Oklahoma.
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Odontología Comunitaria , Atención Odontológica , Accesibilidad a los Servicios de Salud , American Dental Association , California , Servicios de Salud Comunitaria , Relaciones Comunidad-Institución , Curriculum , Delegación Profesional/legislación & jurisprudencia , Auxiliares Dentales/educación , Auxiliares Dentales/legislación & jurisprudencia , Auxiliares Dentales/provisión & distribución , Registros Odontológicos , Registros Electrónicos de Salud , Apoyo Financiero , Promoción de la Salud , Disparidades en Atención de Salud , Humanos , Internet , Internado y Residencia , Área sin Atención Médica , Evaluación de Necesidades , Oklahoma , Proyectos Piloto , Relaciones Profesional-Paciente , Desarrollo de Programa , Evaluación de Programas y Proyectos de Salud , Salud Rural , Estados Unidos , United States Indian Health Service , Poblaciones Vulnerables , Recursos HumanosRESUMEN
BACKGROUND AND STUDY AIMS: Comparison of bowel preparation for colonoscopy in children with either Pico-Salax (sodium picosulphate with magnesium citrate) or polyethylene glycol with electrolyte solution (PEG-ELS). PATIENTS AND METHODS: In this investigator-blinded, randomized controlled trial, 83 children (12.5 +/- 3.1 years) requiring elective colonoscopy at a referral hospital were randomly allocated to Pico-Salax (n = 43) or PEG-ELS (n = 40), and an intention-to treat analysis was applied. Pico-Salax was administered in two doses, one the evening before and one on the morning of the procedure. PEG-ELS was administered over 4 hours. Efficacy was scored using the Ottawa scale and other constructs. Tolerability and toxicity were measured by patient and nursing questionnaires and serum biochemistry. RESULTS: 35 of Pico-Salax patients (81 %) were satisfied or very satisfied with the cleanout, compared with 19 (48 %) in the PEG-ELS group (P = 0.001). No differences were found in bowel cleanout effectiveness, as judged by the Ottawa score (P = 0.24), completion rates (P = 0.69), colonoscopy duration (P = 0.59), need for enemas (P = 0.25), or physician's global impression (P = 0.7). Except for one case of mild dehydration in the Pico-Salax group, no clinically significant adverse events were recorded. Serum biochemistry results were similar between groups except for more hypermagnesemia associated with Pico-Salax and hypokalemia with PEG-ELS; neither was clinically significant. CONCLUSION: Children tolerate Pico-Salax better than PEG-ELS for bowel cleanout before colonoscopy. This study did not demonstrate superiority of effectiveness or safety for either regimen.
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Catárticos/administración & dosificación , Ácido Cítrico/administración & dosificación , Colonoscopía , Óxido de Magnesio/administración & dosificación , Picolinas/administración & dosificación , Polietilenglicoles/administración & dosificación , Administración Oral , Adolescente , Catárticos/efectos adversos , Catárticos/economía , Niño , Preescolar , Citratos , Ácido Cítrico/efectos adversos , Ácido Cítrico/economía , Método Doble Ciego , Costos de los Medicamentos , Femenino , Humanos , Óxido de Magnesio/efectos adversos , Óxido de Magnesio/economía , Masculino , Compuestos Organometálicos , Satisfacción del Paciente , Picolinas/efectos adversos , Picolinas/economía , Polietilenglicoles/efectos adversos , Polietilenglicoles/economíaRESUMEN
We compared the utilization of HIV point-of-care testing (POCT) clinics in a general practice and a genitourinary (GU) medicine service. Retrospective case-note review of patients attending the general practice HIV POCT clinic from February 2005 to July 2007 was undertaken. Those attending the GU medicine service over the same period were used as a comparator group. HIV POCT clinics in general practice when compared with GU medicine services were significantly more likely to be utilized by those of Black ethnicity (Black African 61/370 [16.5%] vs. 107/1231 [8.7%], P < 0.001; Black Caribbean 19/370 [5.1%] vs. 11/1231 [0.9%], P < 0.001 and Black Other 20/370 [5.4%] vs. 26/1231 [2.1%], P = 0.001, respectively). Fewer men who have sex with men attended for HIV POCT in general practice than in GU medicine; 82/238 (34.5%) vs. 337/816 (41.3%), P = 0.058. We have demonstrated that HIV POCT clinics in primary care and GU medicine attract different 'at-risk' groups and provide increased opportunity for testing.
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Instituciones de Atención Ambulatoria/estadística & datos numéricos , Medicina Familiar y Comunitaria/estadística & datos numéricos , Infecciones por VIH/diagnóstico , Aceptación de la Atención de Salud/estadística & datos numéricos , Sistemas de Atención de Punto/estadística & datos numéricos , Adolescente , Adulto , Anciano , Femenino , Enfermedades Urogenitales Femeninas/epidemiología , Infecciones por VIH/epidemiología , Humanos , Londres , Masculino , Enfermedades Urogenitales Masculinas/epidemiología , Persona de Mediana Edad , Estudios Retrospectivos , Conducta SexualRESUMEN
Cancer metastasis involves multiple steps including detachment of the metastatic cells from neighboring cells, the acquisition of motility and invasion to other tissue. All of these steps require the reorganization of the actin cytoskeleton. In this study, we found that the protein palladin, a molecular scaffold with an important function in actin organization, is expressed at higher overall levels in tumors compared with benign breast tissue, and also expressed significantly higher in four invasive breast cancer cell lines when compared with four non-invasive cell lines. In addition, we found that palladin plays a key role in the formation of podosomes. Podosomes are actin-rich structures that function in adhesion and matrix degradation, and have been found in many invasive cell types. Our results show that phorbol ester treatment stimulated the formation of palladin-containing podosomes in invasive, but not in non-invasive cell lines. More importantly, palladin knockdown resulted in decreased podosome formation and a significant reduction in transwell migration and invasive motility. Palladin overexpression induced podosome formation in the non-invasive MCF7 cells, which are otherwise unable to form podosomes, suggesting that palladin plays a critical role in the assembly of podosomes. Overall, these results indicate that palladin overexpression contributes to the invasive behavior of metastatic cells.
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Neoplasias de la Mama/metabolismo , Movimiento Celular , Proteínas del Citoesqueleto/biosíntesis , Citoesqueleto/metabolismo , Matriz Extracelular/metabolismo , Fosfoproteínas/biosíntesis , Actinas/genética , Actinas/metabolismo , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Adhesión Celular/genética , Línea Celular Tumoral , Movimiento Celular/genética , Proteínas del Citoesqueleto/genética , Citoesqueleto/genética , Citoesqueleto/patología , Matriz Extracelular/genética , Matriz Extracelular/patología , Femenino , Humanos , Neoplasias Mamarias Animales/genética , Neoplasias Mamarias Animales/metabolismo , Neoplasias Mamarias Animales/patología , Ratones , Invasividad Neoplásica , Fosfoproteínas/genéticaRESUMEN
OBJECTIVE: Cognitive therapy (CT) has been shown to be an efficacious treatment for persistent psychotic symptoms. However, there is some debate regarding whether this is transportable to real life clinical settings. This study aimed to evaluate the effectiveness of CT for psychosis in a community mental health team (CMHT) setting. METHOD: Patients referred for CT for psychosis were naturalistically allocated (determined by the availability of a therapist) to CT or waiting-list (WL)/treatment-as-usual (TAU). Outcome assessments were performed at WL, pre-CT, post-CT and 1-year follow-up. Data from 59 patients were analysed. RESULTS: Random effects regression analyses showed there was a significant improvement, attributable to CT, on most outcome measures, and that many of the symptomatic improvements were maintained at follow-up. Wilcoxon signed ranks tests indicated that there was a significant reduction in psychiatric hospital use following CT. CONCLUSION: These results confirm that CT is an effective treatment for psychosis that is generalizable to a community setting.
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Terapia Cognitivo-Conductual , Servicios Comunitarios de Salud Mental , Trastornos Psicóticos/terapia , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastornos Psicóticos/psicología , Derivación y Consulta , Análisis de Regresión , Resultado del Tratamiento , Listas de EsperaRESUMEN
OBJECTIVES: To investigate the oscillatory activity in the Parkinsonian subthalamic nucleus using the macro-electrodes for deep brain stimulation. METHODS: During bilateral deep brain stimulating electrode implantation, spontaneous and evoked field potentials were recorded from the subthalamic nucleus (STN) in two patients with Parkinson's disease (PD) during spontaneous resting tremor, passive manipulation of the wrist, and following electrical stimulation of the contralateral STN. RESULTS: Frequency analysis of the STN field potentials recorded during spontaneous resting tremor showed significant coherence with electromyographic activity in the contralateral arm, suggesting a close involvement of the STN in the generation of resting tremor in PD. The STN responded to passive movement of the contralateral wrist, but not to ipsilateral movement. High frequency (100 Hz) electrical stimulation of the STN induced tremor (4 Hz) in both forearms, and also oscillation of the contralateral STN (4 Hz). In contrast, low frequency (5 Hz) stimulation induced contralateral arrhythmic involuntary movement (3 Hz), but without altering the contralateral STN activity. CONCLUSIONS: We propose that the functional connection between the STN and arm muscles is mainly contralateral, but cross talk may occur between bilateral STN via a frequency-dependent pathway.
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Enfermedad de Parkinson/fisiopatología , Núcleo Subtalámico/fisiopatología , Animales , Estimulación Eléctrica , Electrodos Implantados , Electromiografía , Potenciales Evocados/fisiología , Antebrazo/fisiología , Lateralidad Funcional/fisiología , Humanos , Persona de Mediana Edad , Movimiento/fisiología , Músculo Esquelético/fisiopatología , Vías Nerviosas/fisiopatología , Ratas , Temblor/fisiopatologíaRESUMEN
Recent cognitive accounts of psychotic symptoms have suggested that processes involved in the maintenance of emotional disorders may also be implicated in the maintenance of hallucinations and delusions, and particularly emphasise the appraisals of such symptoms as important. Imaginal appraisals have been identified in emotional disorders, and many studies have reported spontaneously occurring images in patients with anxiety disorders. Such images appear to be linked to affect, beliefs and memories. This study examined the occurrence of imagery, using a semi-structured interview, in 35 patients who were experiencing hallucinations and/or delusions and receiving cognitive therapy. The majority of patients (74.3%) reported images, and most of these were recurrent and associated with affect, beliefs and memories. Common themes included images about feared catastrophes associated with paranoia, traumatic memories, and images about the perceived source or content of voices. The theoretical and clinical implications of these findings are discussed and directions for further research considered.
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Terapia Cognitivo-Conductual/métodos , Imaginación , Trastornos Psicóticos/terapia , Adolescente , Adulto , Estudios de Casos y Controles , Deluciones/etiología , Femenino , Alucinaciones/etiología , Humanos , Masculino , Persona de Mediana Edad , Trastornos del Humor/etiología , Trastornos Psicóticos/etiología , Trastornos Psicóticos/psicología , Esquizofrenia , Psicología del EsquizofrénicoRESUMEN
The syndrome of brain atrophy in girls described by Andreas Rett in 1966 [Rett, Wien Klin Wochenschr, 1966;116:723-726] was brought to the attention of the English-speaking world by Hagberg et al. in 1983 [Hagberg et al., Ann Neurol, 1983;14:471-479]. Four clinical stages after the age of 6 months were described in classical cases of Rett syndrome (RS), namely early onset stagnation at 6 months to 1(1/2) years, the rapid destructive stage at 1-3 years, the pseudo-stationary stage from pre-school to school years, and the late motor deterioration stage at 15-30 or more years. The rapid destructive stage causes profound dementia with loss of speech and hand skills, stereotypic movements, ataxia, apraxia, irregular breathing with hyperventilation while awake, and frequently seizures. Most cases are isolated in their families, apart from identical twins. However, linkage studies in rare familial cases suggested a critical region at Xq28. In 1999 American investigators found several mutations in the X-linked gene MECP2 encoding Methyl-CpG-binding protein 2 in a proportion of Rett patients. The protein MeCP2 can bind methylated DNA and when mutated may interfere with transcriptional silencing of other genes and result in abnormal chromatin assembly. Many different mutations of the protein are being studied in humans and in mice. Neuropathological studies have shown decreased brain growth and decreased size of individual neurons, with thinned dendrites in some cortical layers, and abnormalities in substantia nigra, suggestive of deficient synaptogenic development, probably starting before birth. Electrophysiology demonstrates progressively abnormal electroencephalograms (EEG) in the first three stages of the syndrome, with some subsequent improvement and occurrence of pseudoseizures. Neurometabolic factors are discussed in detail, particularly reduced levels of dopamine, serotonin, noradrenaline and choline acetyltransferase (ChAT) in brain, also estimation of nerve growth factors, endorphin, substance P, glutamate and other amino acids and their receptor levels. Autonomic dysfunction is described, particularly reduced vagal and overactive sympathetic activity. Neuro-imaging may be required for further investigation, as shown in the differential diagnosis.
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Sistema Nervioso Central/crecimiento & desarrollo , Proteínas Cromosómicas no Histona , Mutación/genética , Proteínas Represoras , Síndrome de Rett/genética , Síndrome de Rett/fisiopatología , Adolescente , Adulto , Enfermedades del Sistema Nervioso Autónomo/genética , Enfermedades del Sistema Nervioso Autónomo/patología , Enfermedades del Sistema Nervioso Autónomo/fisiopatología , Sistema Nervioso Central/patología , Sistema Nervioso Central/fisiopatología , Niño , Preescolar , Análisis Mutacional de ADN , Proteínas de Unión al ADN/genética , Electroencefalografía , Femenino , Humanos , Lactante , Recién Nacido , Proteína 2 de Unión a Metil-CpG , Neuronas/metabolismo , Neuronas/patología , Síndrome de Rett/patologíaRESUMEN
It has long been suspected that the Rett syndrome (RS) is associated with abnormality of monoaminergic systems, particularly in the brainstem and midbrain, with spread to basal ganglia and cerebral cortex. Early investigators found no significant abnormality in the level of metabolites of noradrenaline, dopamine or serotonin in the spinal fluid, but autopsy brain studies revealed reduced levels of these substances and their metabolites as well as cortical choline acetyltransferase (ChAT) and microtubule-associated proteins (MAP). Levels of Substance P in spinal fluid of RS girls have been reported to be low, while levels of glutamate are raised. Attempts to assess dopaminergic activity by positron emission tomography (PET) in RS have given variable results with different reagents, including [(18)F] 6-fluorodopa. Our group investigated nine RS patients after the age of 12 years and control girls of similar age. Volumetric scans of basal ganglia with Magnetic Resonance Imaging showed a significant reduction in the size of caudate heads and thalami in RS (but not in the size of lentiform nuclei). PET scans with [(11)C] raclopride and with [(18)F] 6-fluorodopa under intravenous propofol anesthesia showed the mean uptake of fluorodopa to be reduced by 13.1% in caudate and by 12.4% in putamen as compared to the controls, whereas dopamine D2 receptor binding, as indicated by raclopride binding, was significantly increased by 9.7% in caudate and by 9.6% in putamen.
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Encéfalo/metabolismo , Vías Nerviosas/metabolismo , Neuronas/metabolismo , Síndrome de Rett/fisiopatología , Adolescente , Adulto , Encéfalo/crecimiento & desarrollo , Encéfalo/patología , Niño , Preescolar , Femenino , Humanos , Lactante , Proteínas Asociadas a Microtúbulos/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Vías Nerviosas/crecimiento & desarrollo , Vías Nerviosas/patología , Neuronas/patología , Neurotransmisores/metabolismo , Cintigrafía , Receptores de Neurotransmisores/metabolismo , Síndrome de Rett/diagnóstico por imagen , Síndrome de Rett/patologíaRESUMEN
We prospectively studied the natural history of untreated acute grade III acromioclavicular separations. Twenty-five patients were treated nonoperatively with a sling for comfort through progressive early range of motion as tolerated. Ten additional uninjured subjects underwent strength testing to evaluate the difference between the dominant and nondominant sides so that patient data could be standardized. The patients were examined at intervals of 6, 12, 24, 36, and 52 weeks after injury, at which time they completed a subjective questionnaire and underwent isometric dynamometer testing as well as military press and bench press strength testing. One patient underwent a surgical procedure at 2 weeks after injury because of cosmetic concerns. Twenty of the 25 patients completed the 1-year evaluation and strength-testing protocol. Subjectively, 4 of the 20 patients (20%) thought that their long-term outcome was suboptimal, although for 3 of them it was not enough to warrant surgery. Objective examination and strength testing of the 20 patients revealed no limitation of shoulder motion in the injured extremity and no difference between sides in rotational shoulder muscle strength. The bench press was the only strength test that showed a significant short-term difference, with the injured extremity being an average of 17% weaker. This study documents the natural history of patients with an untreated acute grade III acromioclavicular separation and provides a reference with which to judge all other proposed methods of treatment.
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Articulación Acromioclavicular/lesiones , Articulación Acromioclavicular/fisiopatología , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Rango del Movimiento Articular , Resultado del TratamientoRESUMEN
Intracellular cytokine staining and flow cytometry can be used to measure T-cell responses to defined antigens. Although CD8+ T-cell responses to soluble proteins are inefficiently detected by this approach, peptides can be used as antigens. Using overlapping peptides spanning an entire protein sequence, CD8+ T-cell responses can be detected to multiple epitopes, regardless of HLA type. In this study, overlapping peptide mixes of various lengths were compared and 15 amino acid peptides with 11 amino acid overlaps were found to stimulate both CD4+ and CD8+ T-cell responses. Such peptide mixes stimulated CD4+ T-cell responses equivalent to those observed with whole recombinant protein, while simultaneously stimulating CD8+ T-cell responses much higher than those observed with whole protein. Although 8-12 amino acid peptides produced the highest level of CD8+ T-cell responses, 15 amino acid peptides were still very effective. Peptides that were 20 amino acids in length, however, did not stimulate strong CD8+ T-cell responses at the same peptide dose. The cytokine responses to individual epitopes added up approximately to the response to the entire mix, demonstrating that large mixes can detect responses in a quantitative fashion. Unlike whole protein antigens, peptide mixes were effective at stimulating responses in both cryopreserved PBMC and blood stored for 24 h at room temperature. Thus, overlapping 15 amino acid peptide mixes may facilitate the analysis of antigen-specific CD4+ and CD8+ T-cell responses by cytokine flow cytometry, using clinical specimens that include shipped blood or cryopreserved PBMC.
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Citocinas/análisis , Citometría de Flujo/métodos , Productos del Gen gag/inmunología , Fragmentos de Péptidos/inmunología , Fosfoproteínas/inmunología , Precursores de Proteínas/inmunología , Linfocitos T/inmunología , Proteínas de la Matriz Viral/inmunología , Ensayos Clínicos como Asunto/métodos , Infecciones por Citomegalovirus/sangre , Epítopos , Infecciones por VIH/sangre , Humanos , Manejo de EspecímenesRESUMEN
Fifty patients who underwent 60 triple innominate osteotomies were reviewed radiographically and clinically using a modified Harris hip score (HHS). Average patient age was 26 years (range: 13-48 years). At average 9-year follow-up (range: 5-14 years), 12 (20%) hips had been converted to total hip arthroplasty (THA) and 4 (7%) hips had incapacitating pain. Sixteen (27%) hips were considered failures. Average modified HHS at final follow-up was 67 (range: 28-91). Forty-nine (98%) of 50 patients reported they would recommend the procedure to others in the same situation. Radiographically, there was significant improvement in the center-to-edge angle of Wiberg and the acetabular angle of Sharp. There also was a statistically significant relationship between failure of the osteotomy and severity of preexisting hip arthrosis as measured by the Tonnis criteria. The results demonstrate triple innominate osteotomy was effective in eliminating pain, but the fact that 27% of hips required or will require THA indicates results may deteriorate with time.
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Luxación de la Cadera/cirugía , Osteotomía/métodos , Acetábulo , Adolescente , Adulto , Artroplastia de Reemplazo de Cadera , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
AIMS: To compare galactose-negative strains of Streptococcus thermophilus and Lactobacillus delbrueckii subspecies bulgaricus isolated from fermented milk products and known to produce exopolysaccharides (EPSs). METHODS AND RESULTS: The structures of the EPSs were determined using nuclear magnetic resonance (NMR) and their genetic relationships determined using restriction endonuclease analysis (REA) and random amplification of polymorphic DNA (RAPD). Similar groupings were apparent by REA and RAPD, and each group produced an EPS with a particular subunit structure. CONCLUSION: Although none of the strains assimilated galactose, all inserted a high proportion of galactose into their EPS when grown in skimmed milk, and fell into three distinct groups. SIGNIFICANCE AND IMPACT OF THE STUDY: This information should help in an understanding of genetic exchanges in lactic acid bacteria.
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Lactobacillus/metabolismo , Polisacáridos Bacterianos/química , Streptococcus/metabolismo , Secuencia de Carbohidratos , Galactosa/metabolismo , Genotipo , Ácido Láctico/metabolismo , Lactobacillus/genética , Conformación Molecular , Polisacáridos Bacterianos/clasificación , Streptococcus/genética , Transducción GenéticaRESUMEN
Streptococcus thermophilus EU20 when grown on skimmed milk secretes a high-molecular-weight exopolysaccharide that is composed of glucose, galactose and rhamnose in a molar ratio of 2:3:2. Using chemical techniques and 1D and 2D-NMR spectroscopy (1H and 13C) the polysaccharide has been shown to possess a heptasaccharide repeating unit having the following structure: [chemical structure: see text]. Treatment of the polysaccharide with mild acid (0.5 M TFA, 100 degrees C for 1 h) liberates two oligosaccharides; the components correspond to the repeating unit and a hexasaccharide equivalent to the repeating unit minus the terminal alpha-L-Rhap.
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Oligosacáridos/química , Polisacáridos Bacterianos/química , Streptococcus/química , Secuencia de Carbohidratos , Datos de Secuencia Molecular , Resonancia Magnética Nuclear Biomolecular , Análisis de SecuenciaRESUMEN
In the first part of the paper, data from pilot plant studies are used to evaluate Cryptosporidium removal by dissolved air flotation (DAF) clarification and dual media filters under challenge conditions. Oocyst removals were investigated for design detention times and hydraulic loadings for winter and spring seasons. Coagulation was optimized for turbidity and removal of natural organic matter. DAF performance was better for spring water temperatures achieving 2.5 +/- 0.3 log removal of oocysts compared to 1.7 +/- 0.3 log removal in the winter. Cumulative log removal across DAF and filtration exceeded 5.4, and was not affected by water temperature. Low turbidities and particle counts are indicators of good treatment and good removals of Cryptosporidium. The second part of the paper uses a mathematical model to predict the fate of Cryptosporidium through a DAF plant and the impact of filter backwash recycle on oocyst build-up in the plant influent. Model predictions show that the fate of Cryptosporidium and the build-up of oocysts in the plant influent depend on: DAF performance, the percent of filtered water production used for backwashing, and the percent of filter backwash recycle flow. A DAF plant with 2.5% filtered water production for backwashing and that achieves 1.6 log removal or greater of oocysts by DAF clarification will not have a build-up of oocysts in the plant influent regardless of the recycle rate. This is because the oocysts are concentrated in the DAF floated sludge and not within granular filters.
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Cryptosporidium/aislamiento & purificación , Purificación del Agua/métodos , Abastecimiento de Agua , Aire , Animales , Filtración/métodos , Proyectos Piloto , SolubilidadRESUMEN
An evaluation of the performance of full-scale packed saturators was made. Measurements of saturator effluent air concentrations, saturator efficiency and precipitated are reported for both cold water and warm water operating conditions. Packed saturators were analyzed over a full range of operating pressures and loading rates. Measured results compared to predicted results based on a comprehensive model for the performance of packed saturators prove the model to be a useful tool in designing efficient and cost effective saturation systems.