5 research outputs found

    Epidemiological study of hypertensive retinopathy in the primary care setting: Retrospective cross-sectional review of retinal photographs

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    Objective: The objective is to estimate the prevalence and grading of hypertensive retinopathy in the primary care setting; examine the patient characteristics associated with hypertensive retinopathy; and examine the association of hypertensive retinopathy and other hypertension complications. Methods: This is a retrospective cross-sectional study. Subjects included adult hypertensive patients with available and gradable retinal photographs. Results: Two hundred fifty-six male hypertensive patients (34.3%) and 491 female hypertensive patients (65.7%) were included. The average duration of hypertension was 7.2 years, and 49.8% and 41.2% of patients were taking one or two antihypertensive medications respectively. Among 1491 qualified retinal photographs (744 right eye and 747 left eye), 24.9%, 62.6%, and 12.5% were classified as showing normal, mild, and moderate hypertensive retinopathy respectively. The three commonest retinal signs were generalized or focal arteriolar narrowing (650 cases, 43.6%), hard exudates (168 cases, 11.3%), and opacity (copper or silver wiring) of the arteriolar wall (166 cases, 11.1%). Patients older than 61 years, having hypertension for more than 15 years, or taking three or more antihypertensive medications were significantly associated with hypertensive retinopathy (P<0.05). Conclusion: In a primary care clinic in Hong Kong, 77.1% of hypertensive patients had hypertensive retinopathy. Advanced hypertensive retinopathy was the commonest target organ damage for hypertensive patients in a primary care clinic

    The mechanism shaping the logistic growth of mutation proportion in epidemics at population scale

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    Virus evolution is a common process of pathogen adaption to host population and environment. Frequently, a small but important fraction of virus mutations are reported to contribute to higher risks of host infection, which is one of the major determinants of infectious diseases outbreaks at population scale. The key mutations contributing to transmission advantage of a genetic variant often grow and reach fixation rapidly. Based on classic epidemiology theories of disease transmission, we proposed a mechanistic explanation of the process that between-host transmission advantage may shape the observed logistic curve of the mutation proportion in population. The logistic growth of mutation is further generalized by incorporating time-varying selective pressure to account for impacts of external factors on pathogen adaptiveness. The proposed model is implemented in real-world data of COVID-19 to capture the emerging trends and changing dynamics of the B.1.1.7 strains of SARS-CoV-2 in England. The model characterizes and establishes the underlying theoretical mechanism that shapes the logistic growth of mutation in population

    Overall survival after concurrent cisplatin-radiotherapy compared with radiotherapy alone in locoregionally advanced nasopharyngeal carcinoma

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    This phase III randomized study compared concurrent cisplatin-radiotherapy (CRT) versus radiotherapy (RT) alone in patients with locoregionally advanced nasopharyngeal carcinoma. A total of 350 patients were randomly assigned to receive external RT alone or concurrently with cisplatin at a dosage of 40 mg/m 2 weekly. The primary endpoint was overall survival, and the median follow-up was 5.5 years. The 5-year overall survival was 58.6% (95% confidence interval [CI] = 50.9% to 66.2%) for the RT arm and 70.3% (95% CI = 63.4% to 77.3%) for the CRT arm. In Cox regression analysis adjusted for T stage, age, and overall stage, the difference in overall survival was statistically significantly in favor of concurrent CRT (P = .049, hazard ratio [HR] = 0.71 [95% CI = 0.5 to 1.0]). Subgroup analysis demonstrated that there was no difference between overall survival in the arms for T1 /T2 stage (P = .74, HR = 0.93 [95% CI = 0.59 to 1.4] ), whereas there was a difference between the arms for T3/T4 stage (P = .013, HR = 0.51 [95% CI = 0.3 to 0.88]), favoring the CRT arm. The regimen of weekly concurrent CRT is a promising standard treatment strategy for locoregionally advanced nasopharyngeal carcinoma patients. © Oxford University Press 2005, all rights reserved.Link_to_subscribed_fulltex
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