10 research outputs found
Novel Dynamics Observed in a Spiking Neural Network Model of the NTS in the Rat Hind-brain
he Nucleus of the Solitary Tract (NTS) is a hind-brain structure in the rat that is the first way-station in taste processing. Its structure and function are poorly understood. Recently our group produced a model, implemented as a spiking neural network (SNN), that successfully replicated experimental data. The model\u27s topology was manually devised and the parameters were set by a genetic algorithm. In order to better understand its information processing capabilities, we probed the model with a variety of input spike patterns and observed a striking winner-take-all decision-making dynamic. We show how the topology and tuned parameters enable this decision to depend on precise spike timing events. It is curious that the experimental data upon which the model was originally evolved did not include winner-take-all examples; this was an emergent capability. It remains for additional experiments on rats to confirm or reject this model prediction
Spatiotemporal Processing of Dynamic Visual Information in the Insect Neural System
Kurtz R. Spatiotemporal Processing of Dynamic Visual Information in the Insect Neural System. In: DiLorenzo P, Victor J, eds. Spike Timing: Mechanism and Function. Frontiers in Neuroscience. 1st ed. Boca Raton: CRC Press; 2013: 1-24
Missed Opportunities: Family History and Behavioral Risk Factors in Breast Cancer Risk Assessment Among a Multiethnic Group of Women
BACKGROUND: Clinician’s knowledge of a woman’s cancer family history (CFH) and counseling about health-related behaviors (HRB) is necessary for appropriate breast cancer care. OBJECTIVE: To evaluate whether clinicians solicit CFH and counsel women on HRB; to assess relationship of well visits and patient risk perception or worry with clinician’s behavior. DESIGN: Cross-sectional population-based telephone survey. PARTICIPANTS: Multiethnic sample; 1,700 women from San Francisco Mammography Registry with a screening mammogram in 2001–2002. MEASUREMENTS: Predictors: well visit in prior year, self-perception of 10-year breast cancer risk, worry scale. Outcomes: Patient report of clinician asking about CFH in prior year, or ever counseling about HRB in relation to breast cancer risk. Multivariate models included age, ethnicity, education, language of interview, insurance/mammography facility, well visit, ever having a breast biopsy/follow-up mammography, Gail-Model risk, Jewish heritage, and body mass index. RESULTS: 58% reported clinicians asked about CFH; 33% reported clinicians ever discussed HRB. In multivariate analysis, regardless of actual risk, perceived risk, or level of worry, having had a well visit in prior year was associated with increased odds (OR = 2.3; 95% CI 1.6, 3.3) that a clinician asked about CFH. Regardless of actual risk of breast cancer, a higher level of worry (OR = 1.9; 95% CI 1.4, 2.6) was associated with increased odds that a clinician ever discussed HRB. CONCLUSIONS: Clinicians are missing opportunities to elicit family cancer histories and counsel about health-related behaviors and breast cancer risk. Preventive health visits offer opportunities for clinicians to address family history, risk behaviors, and patients’ worries about breast cancer
Nigerian Female with Skin Lesions in the Leg and Face: Herpetic Sycosis Folliculitis
Nongenital HSV 1 presents outside the mucus membrane. Our patient had unusual presentation that caused diagnostic dilemma. 30-year-old native Nigerian female coming with fiancée to the United States presented to our service one day after arrival through ER with a lesion on her right ankle. She was diagnosed with cellulitis, started on antibiotics, and admitted to hospital. She had fever of 39.1°C. Head and neck exam showed multiple sized lesions over tongue and palate and inner aspect of lower lip. Abdomen and genital exam was normal. Skin exam showed lesions over the face and lesions over the lateral aspect of the right leg. There was ulcerated lesion over the right lateral malleolus with surrounding erythema and edema. Her tests showed elevated ESR of 98; HIV test was negative; CT scan of the ankle showed no abscess or osteomyelitis. TB quantiferon was indeterminate; AFB stain and culture were negative; HSV IgM was elevated at 1 : 16; RPR was negative; ANA was negative; malaria screen was negative, and blood cultures were negative for bacteria, fungus, and virus. Debrided wound had no growth of bacteria or fungus or virus. This case illustrates the unusual presentation of the HSV1 outside the mucus membrane and how it can be confused with other conditions that required extensive tests. Therapeutic trail with antiviral medications resolved lesions over the leg and face
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Newborn endothelin receptor type B mutant (piebald) mice have a higher resting anal sphincter pressure than newborn C57BL/6 mice
Hirschsprung's disease is characterized by aganglionosis of the distal colon and hypertonicity of the anal sphincter. Endothelin receptor type B mutant (piebald) mice phenotypically resemble infants with Hirschsprung's disease in that these mice are susceptible to developing toxic megacolon because of the absence of ganglion cells in their distal colon. Therefore, we hypothesized that newborn piebald mice would have a higher resting anal sphincter pressure than would newborn wild-type mice. To test this hypothesis, we developed a reliable and reproducible technique for measuring the resting anal sphincter pressure in mice. Heterozygote breeding pairs of endothelin receptor type B mutant mice were purchased and bred in our animal facility. Pregnant, time-dated C57BL/6J mice provided control newborn mice. One-day-old newborn mice were evaluated for resting anal sphincter pressure. Under the operating microscope, a 24-gauge open-tip epidural catheter was placed into the anus until a deflection (approximately 3 to 5 mm) was noticed on a polygraph pressure monitor. Three consecutive measurements were obtained for each mouse. Mean values for each group were determined and compared using Student's t test. The resting anal sphincter pressure (mean +/- standard deviation) in newborn C57BL/6J mice was 13.3 +/- 2.6 mmHg, whereas that in piebald mice 22.7 +/- 2.5 mmHg (P < 0.0001). Therefore, because of their increased resting anal sphincter pressure, piebald mice may provide a useful animal model for the study of Hirschsprung's disease
Energy‑dense diet triggers changes in gut microbiota, reorganization of gut‑brain vagal communication and increases body fat accumulation
Obesity is associated with consumption of energy‑dense diets and development of systemic inflammation. Gut microbiota play a role in energy harvest and inflammation and can influence the change from lean to obese phenotypes. The nucleus of the solitary tract (NTS) is a brain target for gastrointestinal signals modulating satiety and alterations in gut‑brain vagal pathway may promote overeating and obesity. Therefore, we tested the hypothesis that high‑fat diet‑induced changes in gut microbiota alter vagal gut‑brain communication associated with increased body fat accumulation. Sprague‑Dawley rats consumed a low energy‑dense rodent diet (LFD; 3.1 kcal/g) or high energy‑dense diet (HFD, 5.24 kcal/g). Minocycline was used to manipulate gut microbiota composition. 16S Sequencing was used to determine microbiota composition. Immunofluorescence against IB4 and Iba1 was used to determine NTS reorganization and microglia activation. Nodose ganglia from LFD rats were isolated and co‑cultured with different bacteria strains to determine neurotoxicity. HFD altered gut microbiota with increases in Firmicutes/Bacteriodetes ratio and in pro‑inflammatory Proteobacteria proliferation. HFD triggered reorganization of vagal afferents and microglia activation in the NTS, associated with weight gain. Minocycline‑treated HFD rats exhibited microbiota profile comparable to LFD animals. Minocycline suppressed HFD‑induced reorganization of vagal afferents and microglia activation in the NTS, and reduced body fat accumulation. Proteobacteria isolated from cecum of HFD rats were toxic to vagal afferent neurons in culture. Our findings show that diet‑induced shift in gut microbiome may disrupt vagal gut‑brain communication resulting in microglia activation and increased body fat accumulation
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Cardiovascular Testing in the United States during the COVID-19 Pandemic: Volume Recovery and Worldwide Comparison.
PURPOSE: To characterize the recovery of diagnostic cardiovascular procedure volumes in U.S. and non-U.S. facilities in the year following the initial COVID-19 outbreak. MATERIALS AND METHODS: The International Atomic Energy Agency (IAEA) coordinated a worldwide study called the IAEA Noninvasive Cardiology Protocols Study of COVID-19 2 (INCAPS COVID 2), collecting data from 669 facilities in 107 countries, including 93 facilities in 34 U.S. states, to determine the impact of the pandemic on diagnostic cardiovascular procedure volumes. Participants reported volumes for each diagnostic imaging modality used at their facility for March 2019 (baseline), April 2020, and April 2021. This secondary analysis of INCAPS COVID 2 evaluated differences in changes in procedure volume between U.S. and non-U.S. facilities and among U.S. regions. Factors associated with return to prepandemic volumes in the United States were also analyzed in a multivariable regression analysis. RESULTS: Reduction in procedure volumes in April 2020 compared with baseline was similar for U.S. and non-U.S. facilities (-66% vs -71%, P = .27). U.S. facilities reported greater return to baseline in April 2021 than did all non-U.S. facilities (4% vs -6%, P = .008), but there was no evidence of a difference when comparing U.S. facilities with non-U.S. high-income country (NUHIC) facilities (4% vs 0%, P = .18). U.S. regional differences in return to baseline were observed between the Midwest (11%), Northeast (9%), South (1%), and West (-7%, P = .03), but no studied factors were significant predictors of 2021 change from prepandemic baseline. CONCLUSION: The reductions in cardiac testing during the early pandemic have recovered within a year to prepandemic baselines in the United States and NUHICs, while procedure volumes remain depressed in lower-income countries.Keywords: SPECT, Cardiac, Epidemiology, Angiography, CT Angiography, CT, Echocardiography, SPECT/CT, MR Imaging, Radionuclide Studies, COVID-19, Cardiovascular Imaging, Diagnostic Cardiovascular Procedure, Cardiovascular Disease, Cardiac Testing Supplemental material is available for this article. © RSNA, 2023
Cardiovascular Testing in the United States during the COVID-19 Pandemic: Volume Recovery and Worldwide Comparison
PURPOSE: To characterize the recovery of diagnostic cardiovascular procedure volumes in U.S. and non-U.S. facilities in the year following the initial COVID-19 outbreak. MATERIALS AND METHODS: The International Atomic Energy Agency (IAEA) coordinated a worldwide study called the IAEA Noninvasive Cardiology Protocols Study of COVID-19 2 (INCAPS COVID 2), collecting data from 669 facilities in 107 countries, including 93 facilities in 34 U.S. states, to determine the impact of the pandemic on diagnostic cardiovascular procedure volumes. Participants reported volumes for each diagnostic imaging modality used at their facility for March 2019 (baseline), April 2020, and April 2021. This secondary analysis of INCAPS COVID 2 evaluated differences in changes in procedure volume between U.S. and non-U.S. facilities and among U.S. regions. Factors associated with return to prepandemic volumes in the United States were also analyzed in a multivariable regression analysis. RESULTS: Reduction in procedure volumes in April 2020 compared with baseline was similar for U.S. and non-U.S. facilities (-66% vs -71%, = .27). U.S. facilities reported greater return to baseline in April 2021 than did all non-U.S. facilities (4% vs -6%, = .008), but there was no evidence of a difference when comparing U.S. facilities with non-U.S. high-income country (NUHIC) facilities (4% vs 0%, = .18). U.S. regional differences in return to baseline were observed between the Midwest (11%), Northeast (9%), South (1%), and West (-7%, = .03), but no studied factors were significant predictors of 2021 change from prepandemic baseline. CONCLUSION: The reductions in cardiac testing during the early pandemic have recovered within a year to prepandemic baselines in the United States and NUHICs, while procedure volumes remain depressed in lower-income countries. SPECT, Cardiac, Epidemiology, Angiography, CT Angiography, CT, Echocardiography, SPECT/CT, MR Imaging, Radionuclide Studies, COVID-19, Cardiovascular Imaging, Diagnostic Cardiovascular Procedure, Cardiovascular Disease, Cardiac Testing © RSNA, 2023
Worldwide Disparities in Recovery of Cardiac Testing 1 Year Into COVID-19
BACKGROUND The extent to which health care systems have adapted to the COVID-19 pandemic to provide necessary cardiac diagnostic services is unknown.OBJECTIVES The aim of this study was to determine the impact of the pandemic on cardiac testing practices, volumes and types of diagnostic services, and perceived psychological stress to health care providers worldwide.METHODS The International Atomic Energy Agency conducted a worldwide survey assessing alterations from baseline in cardiovascular diagnostic care at the pandemic's onset and 1 year later. Multivariable regression was used to determine factors associated with procedure volume recovery.RESULTS Surveys were submitted from 669 centers in 107 countries. Worldwide reduction in cardiac procedure volumes of 64% from March 2019 to April 2020 recovered by April 2021 in high- and upper middle-income countries (recovery rates of 108% and 99%) but remained depressed in lower middle- and low-income countries (46% and 30% recovery). Although stress testing was used 12% less frequently in 2021 than in 2019, coronary computed tomographic angiography was used 14% more, a trend also seen for other advanced cardiac imaging modalities (positron emission tomography and magnetic resonance; 22%-25% increases). Pandemic-related psychological stress was estimated to have affected nearly 40% of staff, impacting patient care at 78% of sites. In multivariable regression, only lower-income status and physicians' psychological stress were significant in predicting recovery of cardiac testing.CONCLUSIONS Cardiac diagnostic testing has yet to recover to prepandemic levels in lower-income countries. Worldwide, the decrease in standard stress testing is offset by greater use of advanced cardiac imaging modalities. Pandemic-related psychological stress among providers is widespread and associated with poor recovery of cardiac testing. (C) 2022 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation