Caregiver knowledge of obstructive sleep apnoea in Down syndrome

BACKGROUND

Down syndrome (DS) population has a very high prevalence of obstructive sleep apnoea (OSA), but this remains underdiagnosed. Hence, we aimed to evaluate caregiver's knowledge of OSA and related sociodemographic factors that could contribute to OSA screening patterns in this population.

METHODS

An online survey though the LuMind IDSC Foundation focused on OSA diagnosis, treatments and the number of sleep studies performed. Data were compared between subjects born before and after the American Academy of Pediatrics (AAP) recommendations for OSA screening.

RESULTS

Of the caregivers, 724 (parents 96.3%), responded to the survey. The median [interquartile (IQR)] age of the subjects with DS was 12 [20;7] years. The majority (84.3%) had sleep apnoea diagnosis, and half of them were initially referred for a sleep study due to disturbed sleep symptoms. Only 58.7% of the responders were aware of the AAP recommendations. This was linked to higher socioeconomic and/or educational level and to an earlier OSA diagnosis. The median (IQR) age of OSA diagnosis was lowered after the AAP guidelines publication compared with before its publication (3 [4;2] years vs. 10 [18;5] years, P < 0.000). Adenotonsillectomy (81.9%) and continuous positive airway pressure (61.5%) were the most commonly prescribed treatments. Few had discussed other new therapies such as hypoglossal nerve stimulation (16.0%). Only 16.0% of the subjects repeated the sleep study to monitor OSA with ageing, and 30.2% had to wait more than 4 years between studies.

CONCLUSIONS

This study reinforces the need to improve OSA knowledge of caregivers and clinicians of individuals with DS to promote an earlier diagnosis and optimal treatment of OSA in this population.

An open-source automated magnetic optical density meter for analysis of suspensions of magnetic cells and particles

We present a spectrophotometer (optical density meter) combined with electromagnets dedicated to the analysis of suspensions of magnetotactic bacteria. The instrument can also be applied to suspensions of other magnetic cells and magnetic particles. We have ensured that our system, called MagOD, can be easily reproduced by providing the source of the 3D prints for the housing, electronic designs, circuit board layouts, and microcontroller software. We compare the performance of our system to existing adapted commercial spectrophotometers. In addition, we demonstrate its use by analyzing the absorbance of magnetotactic bacteria as a function of their orientation with respect to the light path and their speed of reorientation after the field has been rotated by 90°. We continuously monitored the development of a culture of magnetotactic bacteria over a period of 5 days and measured the development of their velocity distribution over a period of one hour. Even though this dedicated spectrophotometer is relatively simple to construct and cost-effective, a range of magnetic field-dependent parameters can be extracted from suspensions of magnetotactic bacteria. Therefore, this instrument will help the magnetotactic research community to understand and apply this intriguing micro-organism.

Time-Resolved Structural Studies on Insect Flight Muscle after Photolysis of Caged-ATP

The time course of structural changes occurring on ATP-induced relaxation of glycerinated insect flight muscle from the rigor state has been investigated using synchrotron radiation as a source of high intensity x rays and photolysis of caged-ATP to produce a rapid rise in ATP concentration. Temporal resolutions of 1 ms for the strongest equatorial reflections and 5 ms for the 14.5 nm meridional reflection are attainable from single events (i.e., without averaging over several cycles). The equatorial intensity changes completely, the meridional intensity partially, towards their respective relaxed values on a much faster time scale than relaxation of tension. The results suggest that actively cycling bridges present shortly after ATP-release are either too few in number to be detected in the equatorial diffraction pattern or that their structure is different from that of rigor bridges.

Reliability of fractional flow reserve measurements in patients with associated microvascular dysfunction: importance of flow on translesional pressure gradient

Fractional flow reserve (FFR) has been applied with success as a lesion-specific functional indicator of stenosis severity, at least in patients with normal microcirculation. This study sought to assess the reliability of FFR calculations in patients with associated microvascular dysfunction (e.g., post myocardial infarction, or post-MI). First, the effect of coronary flow changes on translesional pressure gradient was assessed. Therefore, intracoronary pressure and flow was recorded simultaneously across 19 non-infarct-related lesions (both pre- and postinterventional lesions with a mean diameter stenosis of 47% +/- 12%). Measurements were performed by means of a pressure and Doppler wire during maximal hyperemia and also during submaximal hyperemia induced by low-dose adenosine. The drop of coronary flow from 48 +/- 23 ml/min during maximal hyperemia to 36 +/- 18 ml/min during submaximal hyperemia was associated with a small decrease in translesional pressure gradient (from 22 +/- 12 mm Hg to 19 +/- 12 mm Hg; P = 0.02) and a small increase in the mean distal/arterial pressure ratio (Pd/Pa) going from 77% +/- 11% to 81% +/- 11% (P = 0.003). Then, intracoronary pressure and flow measurements were compared across 21 non-infarct-related lesions vs. 22 matched infarct-related lesions. For a similar angiographic stenosis severity (% DS = +/- 44%), maximal flow was 48 +/- 22 ml/min in the non-infarct arteries and 37 +/- 26 ml/min in the infarct arteries (P = 0.03), confirming the presence of severe microvascular dysfunction in infarct regions. Similar to the earlier findings, this hyperemic flow reduction in MI patients was associated with a small increase of FFR (= Pd/Pa): 79% +/- 12% in no MI vs. 83% +/- 12% in MI patients (P = 0.3). A reduction of hyperemic flow by +25%, [correction] such as can be found in patients with severely impaired microvascular function, has a limited effect on FFR calculations (+ 5%). This finding allows the application of standard FFR calculations in a more general population of ischemic heart disease, including patients with recent MI.

Insulin allergy resolution following pancreas transplantation alone

Clinically significant immunological reactions to exogenous insulin are classified as local or generalized. Most of the insulin allergies are local reactions which usually improve or resolve spontaneously. Generalized allergic reactions to insulin range in severity from simple urticaria to life-threatening anaphylaxis. Most of the allergic reactions to exogenous insulin are antibody-mediated reactions to antigens such as zinc, protamine, non-insulin proteins, and aggregates of insulin molecules as well as animal antigens. Immunologic reactions to endogenous insulin usually result in insulin resistance. Herein, we report a case in which systemic insulin allergy was intractable, thus requiring a pancreas transplantation which is the first of its case according to the International Pancreas Transplant Registry/United Network for Organ Sharing (IPTR/UNOS) Registry.

Impact of bone density corrections on target dose delivered to the prostate with 4 MV, 6 MV, 10 MV, and 18 MV photons

Doses for definitive prostate irradiation have been derived empirically using low-energy megavoltage equipment without availability of bone density corrections. With their increased availability, higher energy photons are being used more frequently because of their improved depth of penetration. Although inhomogeneity corrections lead to greater accuracy of dose delivery, the clinical utility of corrections in the pelvis is unclear. This study evaluates the effect of bone density on the dose delivered with respect to the photon energy employed. Contours and volumes for 10 patients were taken from computed tomography scans at the center of the prostate gland. Treatment plans for bilateral prostate arc fields were run on the Capintec Treatment Planning System for 4, 6, 10, and 18 MV photon energies. The monitor units needed to deliver 6500 cGy to isocenter without bone correction were used for calculations, both with and without bone correction using the equivalent path length algorithm. The median dose to the isocenter was 6500 cGy for all energies without bone correction. The median doses using the uncorrected monitor units for the 4 MV, 6 MV, 10 MV, and 18 MV photon beams corrected for bone density were 6033, 6062, 6166, and 6228 cGy, respectively. The variance in target doses observed in our patient sample was +/- 2.3%, +/- 2.2%, +/- 1.7%, and +/- 1.4%, respectively, for the 4 MV, 6 MV, 10 MV, and 18 MV beams with bone correction. The increased density of bone in the pelvis does alter the actual dose to the prostate from external beam treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Incidence, mechanism of injury, and treatment of fractures of the patella in children

Fractures of the patella in skeletally immature patients are rare. The charts of 185 patients treated for patella fractures at the University of Kentucky Medical Center between 1976 and 1988 were retrospectively reviewed. The 12 patients of these 185 aged 8 to 16 years were included in this study. The incidence was calculated to be 6.5% of all patella fractures. All patients studied were male with an average age of 12.7 years. Sleeve fractures were the most common type of patella fracture observed (five), followed by transverse fractures (four). Ten of the 12 cases required operative management ranging from irrigation and debridement to open reduction and internal fixation. Partial patellectomy was performed when indicated. Indications for operative management in this age group were similar to those for adults. As in adults, the mechanism of injury was predominantly motor vehicle and motorcycle crashes. Laws requiring seatbelt restraints for children should have a positive effect on the incidence of such fractures resulting from dashboard injuries. One mechanism of injury not reported previously was that of a flexed knee striking the gym wall after performing a basketball lay-up because the basket was placed flush with the wall.

Psychological and social complaints reported by Dutch patients to their family doctors

Ninety-three percent of all problems and complaints reported by patients aged 21 and older to their family physician dealt with somatic disorders, and only 7% with psychosocial problems. Psychological complaints were evenly distributed among major age groups, and between male and female patients. "Social problems" peaked in the middle-age range. The most frequently reported psychological problems were feeling anxious, nervous or tense; feeling irritable, angry, restless or agitated; experiencing feelings of depression; and disturbances of sleep. Marital problems, problems at work, and problems caring for an ill or disabled relative were the most frequently reported "social" reasons for encounter. More women than men reported feelings of depression and marital problems. Men more often felt irritable, angry, restless or agitated, and had more problems at work.

Structural changes during activation of frog muscle studied by time-resolved X-ray diffraction

The pattern given by contracting frog muscle can be followed with high time resolution using synchrotron radiation as a high-intensity X-ray source. We have studied the behaviour of the second actin layer-line (axial spacing of approximately 179 A) at an off-meridional spacing of approximately 0.023 A-1, a region of the diagram that is sensitive to the position of tropomyosin in the thin filaments. In confirmation of earlier work, we find that there is a substantial increase in the intensity of this part of the pattern during contraction. We find that the reflection reaches half its final intensity about 17 milliseconds after the stimulus at 6 degrees C. The changes in the equatorial reflections, which arise from movement of crossbridges towards the thin filaments, occur with a delay of about 12 to 17 milliseconds relative to this change in the actin pattern. In over-stretched muscle, where thick and thin filaments no longer overlap, the changes in the actin second layer-line still take place upon stimulation with a time course and intensity similar to that observed at full overlap. This indicates that tropomyosin movement, in response to calcium binding to troponin, is the first structural step in muscular contraction, and is the prerequisite for myosin binding. A change in intensity similar to that found in contracting muscle is seen in rigor, where tropomyosin is probably locked in the active position. During relaxation the earlier stages in the decrease in intensity of the second actin layer-line take place significantly sooner after the last stimulus than tension decay. In over-stretched muscles the intensity decay is appreciably faster than in the same muscles at rest length, where attached crossbridges may interfere with the return of tropomyosin to its resting position.

Photon correlation spectroscopy of molecular processes in solution

In the initial period of application of photon correlation spectroscopy to molecular phenomena, attention has mainly been focused on the improvement of experimental approaches and instrumental techniques, on feasibility studies of certain cases where theoretical considerations seemed to indicate the prospective usefulness and on various applications that are relatively straightforward, such as the measurement of translational or rotational diffusion coefficients, or the determination of flow velocity by Doppler anemometry.