It is unclear whether there is any postnatal abnormality in brainstem auditory function in late preterm small-for-gestational-age (SGA) infants. We investigated the functional integrity of the ...brainstem auditory pathway at 4 months after term in late preterm SGA infants and defined differences from appropriate-for-gestational age (AGA) infants. The maximum length sequence brainstem evoked response (MLS BAER) was recorded and analyzed in 24 SGA (birthweight < 3rd centile) infants and 28 AGA infants (birthweight > 10th centile). All infants were born at 33–36-week gestation without major perinatal and postnatal problems. We found that I-V interval in SGA infants was shorter than in AGA infants at higher click rates and significantly shorter at the highest rate of 910/s. Of the two smaller intervals, I-III interval was significantly shorter in SGA infants than in AGA infants at higher click rates of 455 and 910/s clicks, whereas III-V interval was similar in the two groups. The III-V/I-III interval ratio in SGA infants tended to be greater than in AGA infants at all rates and was significantly greater at 455 and 910/s clicks. The slope of I-III interval-rate functions in SGA infants was moderately smaller than in AGA infants.
Conclusions
: The main and fundamental difference between late preterm SGA and AGA infants was a significant shortening in the MLS BAER I-III interval in SGA infants at higher click rates, suggesting moderately faster neural conduction in the caudal brainstem regions. Postnatal neural maturation in the caudal brainstem regions is moderately accelerated in late preterm SGA infants.
What is Known:
• At 40 weeks of postconceptional age, late preterm SGA infants manifested a mild delay in neural conduction in the auditory brainstem.
What is New:
• At 56 weeks of postconceptional age, late preterm SGA infants manifested moderately faster neural conduction in the caudal brainstem regions.
• Postnatal neural maturation is moderately accelerated in the caudal brainstem regions of late preterm SGA infants.
We introduce an integration of dynamic light scattering (DLS) and optical coherence tomography (OCT) for high-resolution 3D imaging of heterogeneous diffusion and flow. DLS analyzes fluctuations in ...light scattered by particles to measure diffusion or flow of the particles, and OCT uses coherence gating to collect light only scattered from a small volume for high-resolution structural imaging. Therefore, the integration of DLS and OCT enables high-resolution 3D imaging of diffusion and flow. We derived a theory under the assumption that static and moving particles are mixed within the OCT resolution volume and the moving particles can exhibit either diffusive or translational motion. Based on this theory, we developed a fitting algorithm to estimate dynamic parameters including the axial and transverse velocities and the diffusion coefficient. We validated DLS-OCT measurements of diffusion and flow through numerical simulations and phantom experiments. As an example application, we performed DLS-OCT imaging of the living animal brain, resulting in 3D maps of the absolute and axial velocities, the diffusion coefficient, and the coefficient of determination.
We demonstrate ultrahigh speed spectral / Fourier domain optical coherence tomography (OCT) using an ultrahigh speed CMOS line scan camera at rates of 70,000 - 312,500 axial scans per second. Several ...design configurations are characterized to illustrate trade-offs between acquisition speed, resolution, imaging range, sensitivity and sensitivity roll-off performance. Ultrahigh resolution OCT with 2.5 - 3.0 micron axial image resolution is demonstrated at approximately 100,000 axial scans per second. A high resolution spectrometer design improves sensitivity roll-off and imaging range performance, trading off imaging speed to 70,000 axial scans per second. Ultrahigh speed imaging at >300,000 axial scans per second with standard image resolution is also demonstrated. Ophthalmic OCT imaging of the normal human retina is investigated. The high acquisition speeds enable dense raster scanning to acquire densely sampled volumetric three dimensional OCT (3D-OCT) data sets of the macula and optic disc with minimal motion artifacts. Imaging with approximately 8 - 9 micron axial resolution at 250,000 axial scans per second, a 512 x 512 x 400 voxel volumetric 3D-OCT data set can be acquired in only approximately 1.3 seconds. Orthogonal registration scans are used to register OCT raster scans and remove residual axial eye motion, resulting in 3D-OCT data sets which preserve retinal topography. Rapid repetitive imaging over small volumes can visualize small retinal features without motion induced distortions and enables volume registration to remove eye motion. Cone photoreceptors in some regions of the retina can be visualized without adaptive optics or active eye tracking. Rapid repetitive imaging of 3D volumes also provides dynamic volumetric information (4D-OCT) which is shown to enhance visualization of retinal capillaries and should enable functional imaging. Improvements in the speed and performance of 3D-OCT volumetric imaging promise to enable earlier diagnosis and improved monitoring of disease progression and response to therapy in ophthalmology, as well as have a wide range of research and clinical applications in other areas.
Postlicensure data has identified a causal link between rotavirus vaccines and intussusception in some settings. As rotavirus vaccines are introduced globally, monitoring intussusception will be ...crucial for ensuring safety of the vaccine programs.
To obtain updated information on background rates and clinical management of intussusception, we reviewed studies of intussusception in children <18 years of age published since 2002. We assessed the incidence of intussusception by month of life among children <1 year of age, seasonality, method of diagnosis, treatment, and case-fatality.
We identified 82 studies from North America, Asia, Europe, Oceania, Africa, Eastern Mediterranean, and Central & South America that reported a total of 44,454 intussusception events. The mean incidence of intussusception was 74 per 100,000 (range: 9-328) among children <1 year of age, with peak incidence among infants 5-7 months of age. No seasonal patterns were observed. A radiographic modality was used to diagnose intussusception in over 95% of the cases in all regions except Africa where clinical findings or surgery were used in 65% of the cases. Surgical rates were substantially higher in Africa (77%) and Central and South America (86%) compared to other regions (13-29%). Case-fatality also was higher in Africa (9%) compared to other regions (<1%). The primary limitation of this review relates to the heterogeneity in intussusception surveillance across different regions.
This review of the intussusception literature from the past decade provides pertinent information that should facilitate implementation of intussusception surveillance for monitoring the postlicensure safety of rotavirus vaccines.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To examine postnatal functional status of the brainstem auditory pathway in late preterm infants and detect any postnatal auditory abnormality.
Thirty preterm infants born at 33–36 weeks gestation ...were studied three months after term. None had major perinatal and postnatal complications to minimize confounding effects. Brainstem auditory evoked responses were recorded with 21–91/s clicks.
Compared with postnatal age-matched normal term infants, the late preterm infants did not manifest any major abnormalities in brainstem auditory evoked responses at conventionally used 21/s clicks. At higher click rates, however, the late preterm infants manifested a moderate prolongation in BAER wave V latency. All interpeak intervals tended to be prolonged at higher click rates. The I-V interval was significantly prolonged at 51/s and particularly at 91/s clicks. Both the I-III and III-V intervals were significantly prolonged at 91/s. The late preterm infants also manifested reduced amplitudes of BAER waves III and V at most click rates.
The central components of the brainstem auditory evoked responses were abnormal at higher click rates three months after term in the late preterm infants. Postnatal brainstem auditory function is suboptimal in late preterm infants without major complications. This suboptimal brainstem auditory function may not be clearly shown at term or an earlier stage, but can be shown later. Late preterm infants, although they may not have major complications, should be followed for later auditory development, providing valuable information for improving postnatal care.
The unique environment of the information technology (IT) worker is prone to create work exhaustion, a conceptual component of job burnout. Prior research on the IT worker focuses primarily on the ...antecedent conditions to work exhaustion, uniquely identifying the IT work environment including emotional dissonance, perceived workload, role ambiguity and conflict, autonomy, and fairness of rewards. However, though work exhaustion is a critical product of conditions in the IT work environment, two ignored dimensions of job burnout theory, depersonalization and lessened feelings of personal accomplishment, create a more complete picture and extend current models of IT worker burnout. The extended model with established antecedents is empirically tested through survey techniques and found to hold. Management needs to be aware of these additional symptoms of burnout to circumvent undesirable consequences.
Importance
Intraocular lens (IOL) calculations in post‐refractive cases remain a concern. Our study identifies improved options for surgeons.
Background
To evaluate and compare the prediction ...accuracy of IOL power calculation methods after previous laser refractive surgery using standard keratometry (SK), measured posterior corneal astigmatism (PCA) and total keratometry (TK).
Design
Retrospective consecutive cohort.
Participants
A total of 50 consecutive patients (72 eyes) at a private institution who underwent cataract surgery with prior laser refractive procedures.
Methods
Methods using SK included ASCRS mean, Barrett True‐K no history, Haigis‐L and Shammas IOL formulae. Barrett True‐K using posterior values (True K TK), Haigis and Holladay 1 Double‐K methods using TK were also assessed. Post‐surgery refraction was undertaken at minimum 3 weeks following surgery.
Main Outcome Measures
Arithmetic and absolute IOL refractive prediction errors, variances in mean arithmetic IOL prediction error, and percentage of eyes within ±0.25D, ±0.50D, ±0.75D and ±1.00D of refractive prediction errors were compared.
Results
The Barrett True‐K (TK) provided the lowest mean refractive prediction error (RPE) and variance for both prior myopes and hyperopes undergoing cataract surgery. The Barrett True‐K (TK) exhibited the highest percentages of eyes within ±0.50D, ±0.75D and ±1.00D of the RPE compared to other formulae for prior myopic patients.
Conclusions and Relevance
Accuracy of IOL power calculations in post‐laser eyes can be improved by the addition of posterior corneal values as measured by the IOLMaster 700. The use of total keratometry may supplement outcomes when no prior refraction history is known.
•CLD infants had delayed auditory conduction at more central brainstem regions.•Postnatal central auditory function is adversely affected by neonatal CLD.•Monitoring post-term auditory change is ...warranted for managing CLD infants after term.
Very Low Birthweight (VLBW) infants with neonatal Chronic Lung Disease (CLD) have been found to have functional impairment of the brainstem auditory pathway at term. This study investigated the functional status of the brainstem auditory pathway in VLBW infants with CLD after term for any abnormality.
Fifty-two VLBW infants were recruited at 50 weeks of Postconceptional Age: 25 with neonatal CLD and 27 without CLD. None had any other major complications to minimize confounding effects. Brainstem Auditory Evoked Responses were studied at 21‒91/s click rates.
Compared with those without CLD, VLBW infants with CLD had relatively shorter latencies of BAER waves I and III, associated with a slightly lower BAER threshold. Wave V latency and I‒V interpeak interval did not differ significantly between the two groups of infants. The I‒III interval in infants with CLD was shorter than in those without CLD at 91/s clicks. However, the III‒V interval was significantly longer than in those without CLD at all click rates (all p < 0.05). There were no significant differences in the amplitudes of BAER wave components between the two groups of infants.
The main BAER abnormality in VLBW infants with CLD was a prolonged III‒V interval. Auditory conduction is delayed or impaired at more central regions of the brainstem in CLD infants. After term central auditory function is adversely affected by neonatal CLD. Monitoring post-term change is required to provide valuable information for post-term care of CLD infants.
In vivo optical microscopic imaging techniques have recently emerged as important tools for the study of neurobiological development and pathophysiology. In particular, two-photon microscopy has ...proved to be a robust and highly flexible method for in vivo imaging in highly scattering tissue. However, two-photon imaging typically requires extrinsic dyes or contrast agents, and imaging depths are limited to a few hundred microns. Here we demonstrate Optical Coherence Microscopy (OCM) for in vivo imaging of neuronal cell bodies and cortical myelination up to depths of ~1.3 mm in the rat neocortex. Imaging does not require the administration of exogenous dyes or contrast agents, and is achieved through intrinsic scattering contrast and image processing alone. Furthermore, using OCM we demonstrate in vivo, quantitative measurements of optical properties (index of refraction and attenuation coefficient) in the cortex, and correlate these properties with laminar cellular architecture determined from the images. Lastly, we show that OCM enables direct visualization of cellular changes during cell depolarization and may therefore provide novel optical markers of cell viability.
PDF
