Retinal Oxygen Metabolism and Haemodynamics in Patients With Multiple Sclerosis and History of Optic Neuritis.

Vascular changes and alterations of oxygen metabolism are suggested to be implicated in multiple sclerosis (MS) pathogenesis and progression. Recently developed in vivo retinal fundus imaging technologies provide now an opportunity to non-invasively assess metabolic changes in the neural retina. This study was performed to assess retinal oxygen metabolism, peripapillary capillary density (CD), large vessel density (LVD), retinal nerve fiber layer thickness (RNFLT) and ganglion cell inner plexiform layer thickness (GCIPLT) in patients with diagnosed relapsing multiple sclerosis (RMS) and history of unilateral optic neuritis (ON). 16 RMS patients and 18 healthy controls (HC) were included in this study. Retinal oxygen extraction was modeled using O2 saturations and Doppler optical coherence tomography (DOCT) derived retinal blood flow (RBF) data. CD and LVD were assessed using optical coherence tomography (OCT) angiography. RNFLT and GCIPLT were measured using structural OCT. Measurements were performed in eyes with (MS+ON) and without (MS-ON) history for ON in RMS patients and in one eye in HC. Total oxygen extraction was lowest in MS+ON (1.8 ± 0.2 µl O2/min), higher in MS-ON (2.1 ± 0.5 µl O2/min, p = 0.019 vs. MS+ON) and highest in HC eyes (2.3 ± 0.6 µl O2/min, p = 0.002 vs. MS, ANOVA p = 0.031). RBF was lower in MS+ON (33.2 ± 6.0 µl/min) compared to MS-ON (38.3 ± 4.6 µl/min, p = 0.005 vs. MS+ON) and HC eyes (37.2 ± 4.7 µl/min, p = 0.014 vs. MS+ON, ANOVA p = 0.010). CD, LVD, RNFLT and GCIPL were significantly lower in MS+ON eyes. The present data suggest that structural alterations in the retina of RMS patients are accompanied by changes in oxygen metabolism, which are more pronounced in MS+ON than in MS-ON eyes. Whether these alterations promote MS onset and progression or occur as consequence of disease warrants further investigation. Clinical Trial Registration: ClinicalTrials.gov registry, NCT03401879.

Deep learning differentiates between healthy and diabetic mouse ears from optical coherence tomography angiography images.

We trained a deep learning algorithm to use skin optical coherence tomography (OCT) angiograms to differentiate between healthy and type 2 diabetic mice. OCT angiograms were acquired with a custom-built OCT system based on an akinetic swept laser at 1322 nm with a lateral resolution of ∼13 µm and using split-spectrum amplitude decorrelation. Our data set consisted of 24 stitched angiograms of the full ear, with a size of approximately 8.2 × 8.2 mm, evenly distributed between healthy and diabetic mice. The deep learning classification algorithm uses the ResNet v2 convolutional neural network architecture and was trained on small patches extracted from the full ear angiograms. For individual patches, we obtained a cross-validated accuracy of 0.925 and an area under the receiver operating characteristic curve (ROC AUC) of 0.974. Averaging over multiple patches extracted from each ear resulted in the correct classification of all 24 ears.

Methodology of the German National Sex Survey - GeSiD (German Health and Sexuality Survey).

The German Health and Sexuality Survey (GeSiD) was carried out in 2018/2019 to provide up-to-date measures of sexual behavior, sexual attitudes and sexual lifestyles of the adult population. We describe the methods used in GeSiD which surveyed the general population in Germany aged 18-75 years (with oversampling of younger adults aged 18-35 years). This article focuses on study design, recruitment, and response rate and discusses the strategies implemented to enhance the response rate compared to the pilot study. Overall, 4.955 interviews were completed with a response rate of 30.2%. The data were weighted by age, gender, education, nationality, and region to reduce possible bias. Compared to the German 2018 census, the weighted sample provides good representativeness for selected respondent characteristics. The computer-assisted interviews consisted of a combination of face-to-face and self-completion components. They covered a broad perspective on sexual health, which included topics such as online sexual activities, pleasure, sexual dysfunction, and sexual violence. Reliable data on sexual and reproductive health in Germany are urgently needed for evidence-based prevention and health promotion work, to inform sexual health policy and for cross-national comparisons of the development of sexual behavior in Europe.

Plexus-specific effect of flicker-light stimulation on the retinal microvasculature assessed with optical coherence tomography angiography.

In neural tissues, the coupling between neural activity and blood flow is a physiological key principle in blood flow regulation. We used optical coherence tomography angiography to investigate stimulus-evoked hemodynamic responses in different microvascular layers of the human retina. Twenty-two healthy subjects were included. Vessel density before and during light stimulation was measured using optical coherence tomography angiography and assessed for the superficial, intermediate, and deep capillary plexus of the retinal circulation. Volumetric blood flow was measured using a custom-built Doppler optical coherence tomography system. Our results show that flicker stimulation induced a significant increase in the vessel density of +9.9 ± 6.7% in the superficial capillary plexus, +6.6 ± 1.7% in the intermediate capillary plexus, and +4.9 ± 2.3% in the deep capillary plexus. The hyperemic response of the superficial capillary plexus was significantly higher compared to the intermediate capillary plexus (P = 0.02) and deep capillary plexus (P = 0.002). Volumetric retinal blood flow increased by +39.9 ± 34.9% in arteries and by +29.8 ± 16.8% in veins. In conclusion, we showed a strong increase in the retinal microvascular density in response to light stimulation, with the most pronounced effect in the superficial capillary plexus. This is compatible with the hypothesis that the microvasculature exerts an important function in mediating functional hyperemia in humans.NEW & NOTEWORTHY We present vessel density alterations in response to flicker stimulation using optical coherence tomography angiography and identified the superficial capillary plexus as the layer with the most pronounced effect. This points out the physiological importance of the microvasculature in mediating functional hyperemia and suggests a fine-tuned plexus-specific mechanism to meet cellular metabolic demands.

Deep learning segmentation for optical coherence tomography measurements of the lower tear meniscus.

The tear meniscus contains most of the tear fluid and therefore is a good indicator for the state of the tear film. Previously, we used a custom-built optical coherence tomography (OCT) system to study the lower tear meniscus by automatically segmenting the image data with a thresholding-based segmentation algorithm (TBSA). In this report, we investigate whether the results of this image segmentation algorithm are suitable to train a neural network in order to obtain similar or better segmentation results with shorter processing times. Considering the class imbalance problem, we compare two approaches, one directly segmenting the tear meniscus (DSA), the other first localizing the region of interest and then segmenting within the higher resolution image section (LSA). A total of 6658 images labeled by the TBSA were used to train deep convolutional neural networks with supervised learning. Five-fold cross-validation reveals a sensitivity of 96.36% and 96.43%, a specificity of 99.98% and 99.86% and a Jaccard index of 93.24% and 93.16% for the DSA and LSA, respectively. Average segmentation times are up to 228 times faster than the TBSA. Additionally, we report the behavior of the DSA and LSA in cases challenging for the TBSA and further test the applicability to measurements acquired with a commercially available OCT system. The application of deep learning for the segmentation of the tear meniscus provides a powerful tool for the assessment of the tear film, supporting studies for the investigation of the pathophysiology of dry eye-related diseases.

Cutaneous optical coherence tomography for longitudinal volumetric assessment of intradermal volumes in a mouse model.

Clinical evaluation of skin lesions requires precise and reproducible technologies for their qualitative and quantitative assessment. In this study, we investigate the applicability of a custom-built dermatologic OCT system for longitudinal assessment of intradermal volumes in a mouse model. The OCT, based on an akinetic swept laser working at 1310 nm was employed for visualization and quantification of intradermal deposits of three different hyaluronic acid-based hydrogel formulations - one commercial and two test substances. Hydrogels were applied in 22 BALB/c mice, and measurements were performed over a six-month time period. All hydrogels increased in volume within the first weeks and degraded steadily thereafter. The half-lifes of the test hydrogels (27.2 ± 13.6 weeks for Hydrogel 1, 31.5 ± 17.2 weeks for Hydrogel 2) were higher in comparison to the commercially available HA hydrogel (21.4 ± 12.0 weeks), although differences were not significant. The sphericity parameter was used for evaluation of the deposit geometry. While on the injection day the sphericities were similar (~0.75 ± 0.04), at later time points significant differences between the different test substances were found (T24: PRV 0.59 ± 0.09, Hydrogel 1 0.70 ± 0.11, Hydrogel 2 0.78 ± 0.07; p ≤ 0.012 for all pairs). This study shows the applicability of OCT imaging for quantitative assessment of the volumetric behavior of intradermal deposits in vivo.

Characterization of dry eye disease in a mouse model by optical coherence tomography and fluorescein staining.

A custom-built ultrahigh-resolution optical coherence tomography (UHR-OCT) system and fluorescein staining were employed for investigation of a scopolamine induced dry eye mouse model. Acquired data was used to evaluate common and complementary findings of the two modalities. Central corneal thickness as measured by UHR-OCT increased significantly over the study period of 24 hours, from 89.0 ± 3.57 µm to 92.2 ± 4.07 µm. Both techniques were able to show corneal lesions with a large range of severity. Localized fluorescein staining was detected in 5% and diffuse staining in 45% of cases where no epithelial damage was visible with OCT. However, OCT revealed stromal defects in 6% and endothelial defects in 18% of the cases, which could not be visualized via fluorescein staining. Thus, while fluorescein staining widely detected defects of the corneal surface in a mouse model of dry eye disease, OCT non-invasively revealed additional information about defect depth and involvement of particular layers.

Comparison of optical coherence tomography and high frequency ultrasound imaging in mice for the assessment of skin morphology and intradermal volumes.

Optical coherence tomography (OCT) and high-frequency ultrasound (HFUS), two established imaging modalities in the field of dermatology, were evaluated and compared regarding their applicability for visualization of skin tissue morphology and quantification of murine intradermal structures. The accuracy and reproducibility of both methods were assessed ex vivo and in vivo using a standardized model for intradermal volumes based on injected soft tissue fillers. OCT revealed greater detail in skin morphology, allowing for detection of single layers due to the superior resolution. Volumetric data measured by OCT (7.9 ± 0.3 µl) and HFUS (7.7 ± 0.5 µl) were in good agreement and revealed a high accuracy when compared to the injected volume of 7.98 ± 0.8 µl. In vivo, OCT provided a higher precision (relative SD: 26% OCT vs. 42% HFUS) for the quantification of intradermal structures, whereas HFUS offered increased penetration depth enabling the visualization of deeper structures. A combination of both imaging technologies might be valuable for tumor assessments or other dermal pathologies in clinical settings.

Automated segmentation of dermal fillers in OCT images of mice using convolutional neural networks.

We present a system for automatic determination of the intradermal volume of hydrogels based on optical coherence tomography (OCT) and deep learning. Volumetric image data was acquired using a custom-built OCT prototype that employs an akinetic swept laser at ~1310 nm with a bandwidth of 87 nm, providing an axial resolution of ~6.5 µm in tissue. Three-dimensional data sets of a 10 mm × 10 mm skin patch comprising the intradermal filler and the surrounding tissue were acquired. A convolutional neural network using a u-net-like architecture was trained from slices of 100 OCT volume data sets where the dermal filler volume was manually annotated. Using six-fold cross-validation, a mean accuracy of 0.9938 and a Jaccard similarity coefficient of 0.879 were achieved.

Ultrahigh-resolution anterior segment optical coherence tomography for analysis of corneal microarchitecture during wound healing.

PURPOSE: To employ ultrahigh-resolution (UHR) optical coherence tomography (OCT) for investigation of the early wound healing process in corneal epithelium. METHODS: A custom-built UHR-OCT system assessed epithelial healing in human keratoconic cornea after epi-off crosslinking (CXL) procedure and a wound healing model in rabbits with iatrogenic corneal injury. 3D OCT data sets enhanced obtaining epithelial thickness maps and evaluation of reepithelization stage. Accompanying changes in deeper corneal microarchitecture were analysed. RESULTS: The mean central corneal thickness in 40 eyes with keratoconus at baseline was 482.7 ± 38.2 µm, while mean central epithelial thickness (CET) was 43.8 ± 6.4 µm. At the final visit 20 ± 5 days post-CXL procedure, CET was 35.0 ± 5.8 µm, significantly thinner after reepithelization (p < 0.001). Surgical success was assessed at the final visit through the demarcation line (DL), identified at 43.7 ± 13.5% stromal depth. In rabbits, the mean CET in 20 eyes at baseline was 35.9 ± 2.6 µm. In rabbits that revealed complete wound closure (10/20 eyes) at the last study day at 72 hr, CET was significantly thinner compared to baseline (30.4 ± 2.8 µm versus 35.4 ± 2.9 µm, p = 0.005). An intra-stromal landmark indicating early keratocyte apoptosis was measured at 30.0 ± 5.1% stromal depth. Epithelial thickness maps showed the time-course of corneal healing. CONCLUSION: Ultrahigh-resolution (UHR)-OCT provided precise assessment of epithelial wound and its healing by 3D-mapping. In addition, microarchitectural changes in the cornea in early phases of epithelial healing were revealed.

CorneaNet: fast segmentation of cornea OCT scans of healthy and keratoconic eyes using deep learning.

Deep learning has dramatically improved object recognition, speech recognition, medical image analysis and many other fields. Optical coherence tomography (OCT) has become a standard of care imaging modality for ophthalmology. We asked whether deep learning could be used to segment cornea OCT images. Using a custom-built ultrahigh-resolution OCT system, we scanned 72 healthy eyes and 70 keratoconic eyes. In total, 20,160 images were labeled and used for the training in a supervised learning approach. A custom neural network architecture called CorneaNet was designed and trained. Our results show that CorneaNet is able to segment both healthy and keratoconus images with high accuracy (validation accuracy: 99.56%). Thickness maps of the three main corneal layers (epithelium, Bowman's layer and stroma) were generated both in healthy subjects and subjects suffering from keratoconus. CorneaNet is more than 50 times faster than our previous algorithm. Our results show that deep learning algorithms can be used for OCT image segmentation and could be applied in various clinical settings. In particular, CorneaNet could be used for early detection of keratoconus and more generally to study other diseases altering corneal morphology.

Valor del ultrasonido de hombro en el síndrome de pinzamiento anterior / Anterior impingement syndrome: sonography of the shoulder

Propósito. El síndrome de pinzamiento anterior de Goldwaith es de menor frecuencia que el superior, es suma importancia de identificación por métodos de imágenes debido a que los síntomas y el tratamiento son diferentes. Material y método. Se utiliza un equipo ATK HDI 3000, estudiando 450 pacientes entre enero de 2001 y junio de 2003, detectando 29 casos de pinzamiento anterior. Se usaron transductores de 5-7,5 MHz y 10-12 MHz. El espacio coracohumeral tomado como normal varió entre 5 y 11 mm. Resultados. Se encontraron 15 desgarros subescapulares, 12 parciales, 3 totales, 4 luxaciones subluxaciones. Conclusión. El ultrasonido no solo muestra la anatomía y patología del espacio coracohumeral, sino también las relaciones dinámicas

Valor del ultrasonido de hombro en el síndrome de pinzamiento anterior / Anterior impingement syndrome: sonography of the shoulder

Propósito. El síndrome de pinzamiento anterior de Goldwaith es de menor frecuencia que el superior, es suma importancia de identificación por métodos de imágenes debido a que los síntomas y el tratamiento son diferentes. Material y método. Se utiliza un equipo ATK HDI 3000, estudiando 450 pacientes entre enero de 2001 y junio de 2003, detectando 29 casos de pinzamiento anterior. Se usaron transductores de 5-7,5 MHz y 10-12 MHz. El espacio coracohumeral tomado como normal varió entre 5 y 11 mm. Resultados. Se encontraron 15 desgarros subescapulares, 12 parciales, 3 totales, 4 luxaciones subluxaciones. Conclusión. El ultrasonido no solo muestra la anatomía y patología del espacio coracohumeral, sino también las relaciones dinámicas (AU)

Mono-ADP-ribosyltransferases in human monocytes: regulation by lipopolysaccharide.

ADP-ribosyltransferase activity was shown to be present on the surface of human monocytes. Incubating the cells in the presence of BSA leads to an increase in enzyme activity. The acceptor amino acid mainly responsible for the ADP-ribose bond was identified as a cysteine residue. An increase in ADP-ribosyltransferase activity was observed when cells were treated for 16 h with bacterial lipopolysaccharide (LPS). Possible candidates for catalysing the reaction are mono-ADP-ribosyltransferases (ARTs). When measuring expression of the mRNA of ART1, 3, 4 and 5, only ART3 mRNA was detected in unstimulated monocytes. Upon stimulation for 16 h with LPS, lipoteichoic acid or peptidoglycan, ART4 mRNA was found to be expressed. No ART4 signal appeared after a 4 h exposure of the cells to LPS. Cell-surface proteins were labelled when incubating monocytes with [(32)P]NAD(+). Their molecular masses were 29, 33, 43, 45, 60 and 82 kDa. In response to LPS an additional protein of 31 kDa was found to be labelled. The bound label was resistant to treatment with NH(2)OH but sensitive to HgCl(2), characteristic of a cysteine-linked ADP-ribosylation.

Embarazo ectópico: hallazgos ecográficos por vía transvaginal / Ectopic pregnancy: evaluation with transvaginal sonography

Se revisaron retrospectivamente los hallazgos de 70 ecografías transvaginales de 62 pacientes con diagnóstico confirmado de embarazo ectópico. Fueron analizados el espesor endometrial y la presencia o ausencia de quistes deciduales, seudosacos, anillos anexiales ("ring" anexial), masas anexiales, cuerpos lúteos y líquido libre. En algunos casos se empleó el exámen Doppler. Los resultados fueron correlacionados con el cuadro clínico, entre sí y con los valores plasmáticos de subunidad Beta de la HCG. Se los comparó asimismo con la bibliografía internacional. Se concluye afirmando que los signos del embarazo ectópico varían en función del cuadro clínico y del tiempo de evolución, y que es necesaria una cuidadosa búsqueda de los mismos ante la sospecha clínica

Embarazo ectópico: hallazgos ecográficos por vía transvaginal / Ectopic pregnancy: evaluation with transvaginal sonography

Se revisaron retrospectivamente los hallazgos de 70 ecografías transvaginales de 62 pacientes con diagnóstico confirmado de embarazo ectópico. Fueron analizados el espesor endometrial y la presencia o ausencia de quistes deciduales, seudosacos, anillos anexiales ("ring" anexial), masas anexiales, cuerpos lúteos y líquido libre. En algunos casos se empleó el exámen Doppler. Los resultados fueron correlacionados con el cuadro clínico, entre sí y con los valores plasmáticos de subunidad Beta de la HCG. Se los comparó asimismo con la bibliografía internacional. Se concluye afirmando que los signos del embarazo ectópico varían en función del cuadro clínico y del tiempo de evolución, y que es necesaria una cuidadosa búsqueda de los mismos ante la sospecha clínica (AU)

Novobiocin is a novel inducer of CD38 on cells of the myelomonocytic lineage.

KG-1a, HL-60 and U-937 cells, which represent different stages of myelopoiesis, showed growth retardation in response to the coumarin antibiotic novobiocin. Novobiocin was found to increase CD38 expression (in all three cell lines) and to induce differentiation along the monocytic path in HL-60 and U-937 cells but not in KG-1a cells. The increase in surface expression of CD38 was matched by NAD glycohydrolase activity and by increases in the level of specific mRNA, indicating that the gene product is active and that regulation occurs at the level of transcription or mRNA stability. Of the three cell lines tested, only the early KG-1a expressed N-cadherin, a member of Ca(2+)-dependent adhesion molecules involved in embryonic differentiation processes. In contrast to CD38, N-cadherin was slightly down-regulated pointing to a specific role of novobiocin in gene regulation.

Invaginación intestinal en adultos: diagnóstico mediante el uso de TC y US, correlación imagenológica-quirúrgica-patológica / Intussusception in adults: US and CT findings

La invaginación intestinal es la penetración de una porción intestinal en otra adyacente. Es poco frecuente en adultos y en un 80-90 por ciento de los casos es de origen tumoral. Clínicamente se manifiesta como una obstrucción. A propósito de cuatro casos, los autores destacan las características más relevantes de ésta entidad, la utilidad de la tomografía computada (TC) y el ultrasonido (US) para su diagnóstico y posterior confirmación quirúrgico-patológica. En TC existen tres patrones diferentes que reflejan su severidad y duración: el signo de Target, masa en forma de salchicha y masa reniforme. Los patrones ecográficos son el pseudorriñón, rosquilla y luna creciente, siendo éste último, el único signo ecográfico distintivo de ésta enfermedad. La presencia de flujo Doppler sugiere que la intususcepción podría ser reducida. La presencia de fluído peritoneal significa isquemia e irreductibilidad. Tanto la TC como el US demuestran ser métodos sensibles y específicos en el diagnóstico, definición de la etiología y evaluación de las complicaciones

Invaginación intestinal en adultos: diagnóstico mediante el uso de TC y US, correlación imagenológica-quirúrgica-patológica / Intussusception in adults: US and CT findings

La invaginación intestinal es la penetración de una porción intestinal en otra adyacente. Es poco frecuente en adultos y en un 80-90 por ciento de los casos es de origen tumoral. Clínicamente se manifiesta como una obstrucción. A propósito de cuatro casos, los autores destacan las características más relevantes de ésta entidad, la utilidad de la tomografía computada (TC) y el ultrasonido (US) para su diagnóstico y posterior confirmación quirúrgico-patológica. En TC existen tres patrones diferentes que reflejan su severidad y duración: el signo de Target, masa en forma de salchicha y masa reniforme. Los patrones ecográficos son el pseudorriñón, rosquilla y luna creciente, siendo éste último, el único signo ecográfico distintivo de ésta enfermedad. La presencia de flujo Doppler sugiere que la intususcepción podría ser reducida. La presencia de fluído peritoneal significa isquemia e irreductibilidad. Tanto la TC como el US demuestran ser métodos sensibles y específicos en el diagnóstico, definición de la etiología y evaluación de las complicaciones (AU)

Embarazo ectópico: hallazgos ecográficos por vía transvaginal / Ectopic pregnancy: evaluation with transvaginal sonography

Se revisaron retrospectivamente los hallazgos de 70 ecografías transvaginales de 62 pacientes con diagnóstico confirmado de embarazo ectópico. Fueron analizados el espesor endometrial y la presencia o ausencia de quistes deciduales, seudosacos, anillos anexiales ("ring" anexial), masas anexiales, cuerpos lúteos y líquido libre. En algunos casos se empleó el exámen Doppler. Los resultados fueron correlacionados con el cuadro clínico, entre sí y con los valores plasmáticos de subunidad Beta de la HCG. Se los comparó asimismo con la bibliografía internacional. Se concluye afirmando que los signos del embarazo ectópico varían en función del cuadro clínico y del tiempo de evolución, y que es necesaria una cuidadosa búsqueda de los mismos ante la sospecha clínica