Патология верхних конечностей у детей с мукополисахаридозами

Background. Despite the success in the treatment of children with mucopolysaccharidoses (MPS) as a result of the widespread of  enzyme  replacement  therapy  and  hematopoietic  stem  cells  transplantation,  orthopedic  manifestations  continue  to  be a  significant  problem,  while  the  pathology  of  the  upper  limbs  in  children  with  MPS  is  not  sufficiently  represented  in  the literature. The aim of this studywas to analyze orthopedic and neurological manifestations in the upper extremities of children with  mucopolysaccharidosis  based  on  a  sequential  case  series. Materials  and  Methods. We  carried  out  a  comprehensive analysis of clinical and radiological involvement of the upper extremities in 49 patients with MPS. Results. The most common complaints reated to the upper extremities were difficulties in the daily activities (dressing, self-care, playing), impairment of the fine motor skills, and muscle weakness. The most frequent clinical manifestations related to the upper extremities were limited active shoulder abduction, impaired hand grip, flexion contractures of the elbow joint, ulnar deviation of the hand. All patients with MPS types I, II, and VI had limited active and passive extension and flexion of the metacarpophalangeal and interphalangeal joints. In patients with MPS IV, hypermobility of the hand joints prevailed. We noticed minimal presence of typical clinical manifestations related to compression of the median nerve secific for carpal tunnel syndrome. The majority of patients showed a decrease in tendon and periosteal reflexes. The most pronounced decrease in muscle strength was observed in to extensors (elbow, fingers) and shoulder abductors, which may contribute to the predominant formation of a flexion pattern of contractures. On radiographs of the hand, the “melting sugar” symptom and shortening of the metacarpal bones were observed in most patients. Conclusion.Clinical and radiological manifestations related to the upper extremities take  place  in  all  types  of  the  mPS,  and  lead  to  functional  disorders  that  complicate  daily  life  and  self-care.  Upper  limb pathology in children with MPS requires earlier detection and more active treatment after comprehensive risk assessment.Актуальность. Несмотря на успехи в лечении детей с мукополисахаридозами (МПС) в результате широкого внедрения ферментзаместительной терапии и трансплантации гематопоэтических стволовых клеток, ортопедические проявления продолжают оставаться значительной проблемой, при этом патология верхних конечностей у детей с МПС отражена в литературе недостаточно.Материалы и методы Нами проведен комплексный анализ клинических и рентгенологических проявлений со стороны верхних конечностей у 49 пациентов с МПС.Результаты. Наиболее частыми жалобами со стороны верхних конечностей были неловкость при выполнении повседневных движений (одевание, самообслуживание, пользование предметами), нарушение мелкой моторики, мышечная слабость. Наиболее частым клиническим проявлением со стороны верхних конечностей было ограничение активного отведения плеча, нарушение кистевого схвата, сгибательные контрактуры в локтевом суставе, ульнарная девиация кисти. У всех пациентов с МПС I, II и VI типов имело место ограничение активного и пассивного разгибания и сгибания пястнофаланговых и межфаланговых суставов. У пациентов с МПС IV преобладала гипермобильность суставов кисти. При оценке симптомов, характерных для синдрома карпального канала отмечено отсутствие типичных клинических проявлений, обусловленных компрессией срединного нерва. У большинства пациентов отмечалось снижение сухожильных и периостальных рефлексов. Наиболее выраженное снижение силы мышц отмечалось в отношении разгибания пальцев кисти, отведения плеча и разгибания в локтевом суставе, что может способствовать формировании флексионного паттерна контрактур суставов верхних конечностей. На рентгенограммах кисти симптом «тающего сахара» и укорочение пястных костей наблюдались у большинства пациентов.Заключение. Клинические и рентгенологические проявления со стороны верхних конечностей наблюдаются при всех изученных нами типах заболевания, и приводят к функциональным нарушениям, затрудняющим повседневную жизнь и самообслуживание. Патология верхних конечностей у детей с МПС требует более раннего выявления и более активной лечебной тактики после всесторонней оценки рисков

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Electron-Electron Scattering in a Double Quantum Dot: Effective Mass Approach

We present a theoretical description of the first-order scattering of interacting electrons and holes in a double quantum dot. Assuming infinitely high walls, strong confinement, and a two-band approximation, we derive general expressions for the two-particle matrix elements of the screened Coulomb potential. We also determine the selection rules for different scattering channels and consider special cases where the corresponding matrix elements can be represented by simple analytical expressions. Numerical calculations of the matrix elements and an analysis of their dependence on the geometrical and material parameters of the double quantum dot have also been performed