Johns Hopkins University School of Medicine

About: Johns Hopkins University School of Medicine is a healthcare organization based out in Baltimore, Maryland, United States. It is known for research contribution in the topics: Population & Medicine. The organization has 44277 authors who have published 79222 publications receiving 4788882 citations.

Human α-synuclein-harboring familial Parkinson's disease-linked Ala-53 → Thr mutation causes neurodegenerative disease with α-synuclein aggregation in transgenic mice

Abstract: Mutations in alpha-synuclein (alpha-Syn) cause Parkinson's disease (PD) in a small number of pedigrees with familial PD. Moreover, alpha-Syn accumulates as a major component of Lewy bodies and Lewy neurites, intraneuronal inclusions that are neuropathological hallmarks of PD. To better understand the pathogenic relationship between alterations in the biology of alpha-Syn and PD-associated neurodegeneration, we generated multiple lines of transgenic mice expressing high levels of either wild-type or familial PD-linked Ala-30 --> Pro (A30P) or Ala-53 --> Thr (A53T) human alpha-Syns. The mice expressing the A53T human alpha-Syn, but not wild-type or the A30P variants, develop adult-onset neurodegenerative disease with a progressive motoric dysfunction leading to death. Pathologically, affected mice exhibit neuronal abnormalities (in perikarya and neurites) including pathological accumulations of alpha-Syn and ubiquitin. Consistent with abnormal neuronal accumulation of alpha-Syn, brain regions with pathology exhibit increases in detergent-insoluble alpha-Syn and alpha-Syn aggregates. Our results demonstrate that the A53T mutant alpha-Syn causes significantly greater in vivo neurotoxicity as compared with other alpha-Syn variants. Further, alpha-Syn-dependent neurodegeneration is associated with abnormal accumulation of detergent-insoluble alpha-Syn.

Incubation periods of acute respiratory viral infections: a systematic review

Abstract: Summary Knowledge of the incubation period is essential in the investigation and control of infectious disease, but statements of incubation period are often poorly referenced, inconsistent, or based on limited data. In a systematic review of the literature on nine respiratory viral infections of public-health importance, we identified 436 articles with statements of incubation period and 38 with data for pooled analysis. We fitted a log-normal distribution to pooled data and found the median incubation period to be 5·6 days (95% CI 4·8–6·3) for adenovirus, 3·2 days (95% CI 2·8–3·7) for human coronavirus, 4·0 days (95% CI 3·6–4·4) for severe acute respiratory syndrome coronavirus, 1·4 days (95% CI 1·3–1·5) for influenza A, 0·6 days (95% CI 0·5–0·6) for influenza B, 12·5 days (95% CI 11·8–13·3) for measles, 2·6 days (95% CI 2·1–3·1) for parainfluenza, 4·4 days (95% CI 3·9–4·9) for respiratory syncytial virus, and 1·9 days (95% CI 1·4–2·4) for rhinovirus. When using the incubation period, it is important to consider its full distribution: the right tail for quarantine policy, the central regions for likely times and sources of infection, and the full distribution for models used in pandemic planning. Our estimates combine published data to give the detail necessary for these and other applications.

Patients with depression are less likely to follow recommendations to reduce cardiac risk during recovery from a myocardial infarction.

Abstract: Background Patients with depression are at greater risk of cardiac death in the first few months after a myocardial infarction (MI). This study was performed to determine whether depression affects adherence to recommendations intended to reduce the risk of cardiac events after an MI. Methods All consenting patients admitted to a university-affiliated teaching hospital during an 18-month period were interviewed 3 to 5 days following an acute MI using the Beck Depression Inventory to assess symptoms of depression and using the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition , to determine the presence of major depression and/or dysthymia. Accessible survivors (n=204; 116 men and 88 women) were interviewed by telephone 4 months later using the Medical Outcomes Study Specific Adherence Scale to measure self-reported adherence to recommendations to modify cardiac risk. Results Patients who were found in the hospital to have symptoms of at least mild to moderate depression (Beck Depression Inventory score ≥10, n=35 [17.2%]) or to have major depression and/or dysthymia (n=31 [15.2%]) reported lower adherence to a low-fat diet, regular exercise, reducing stress, and increasing social support 4 months later. Those with major depression and/or dysthymia also reported taking medications as prescribed less often than those without major depression and/or dysthymia. Diabetic patients with major depression and/or dysthymia were less likely to follow a diet for patients with diabetes than diabetic patients without depression. Conclusions Patients with depression following an acute MI are less likely to adhere to recommended behavior and lifestyle changes intended to reduce the risk of subsequent cardiac events. This finding could explain why depression in the hospital is related to long-term prognosis in patients recovering from an MI.

S-Nitrosylation of Parkin Regulates Ubiquitination and Compromises Parkin's Protective Function

Abstract: Parkin is an E3 ubiquitin ligase involved in the ubiquitination of proteins that are important in the survival of dopamine neurons in Parkinson's disease (PD). We show that parkin is S-nitrosylated in vitro, as well as in vivo in a mouse model of PD and in brains of patients with PD and diffuse Lewy body disease. Moreover, S-nitrosylation inhibits parkin's ubiquitin E3 ligase activity and its protective function. The inhibition of parkin's ubiquitin E3 ligase activity by S-nitrosylation could contribute to the degenerative process in these disorders by impairing the ubiquitination of parkin substrates.

Treatment of Atrial Fibrillation With Antiarrhythmic Drugs or Radiofrequency Ablation Two Systematic Literature Reviews and Meta-Analyses

Abstract: Background— Although radiofrequency catheter ablation (RFA) has evolved from an experimental procedure to an important treatment option for atrial fibrillation, the relative safety and efficacy of ...