A novel theory for rapid localization of the transverse-sigmoid sinus junction and "keyhole" in the retrosigmoid keyhole approach: micro-anatomical study, technique nuances, and clinical application.

To determine a rapid and accurate method for locating the keypoint and "keyhole" in the suboccipital retrosigmoid keyhole approach. (1) Twelve adult skull specimens were selected to locate the anatomical landmarks on the external surface of the skull.The line between the infraorbital margin and superior margin of the external acoustic meatus was named the baseline. A coordinate system was established using the baseline and its perpendicular line through the top point of diagastric groove.The perpendicular distance (x), and the horizontal distance (y) between the central point of the "keyhole" and the top point of the digastric groove in that coordinate system were measured. The method was applied to fresh cadaveric specimens and 53 clinical cases to evaluate its application value. (1) x and y were 14.20 ± 2.63 mm and 6.54 ± 1.83 mm, respectively (left) and 14.95 ± 2.53 mm and 6.65 ± 1.61 mm, respectively (right). There was no significant difference between the left and right sides of the skull (P > 0.05). (2) The operative area was satisfactorily exposed in the fresh cadaveric specimens, and no venous sinus injury was observed. (3) In clinical practice, drilling did not cause injury to venous sinuses, the mean diameter of the bone windows was 2.0-2.5 cm, the mean craniotomy time was 26.01 ± 3.46 min, and the transverse and sigmoid sinuses of 47 patients were well-exposed. We propose a "one point, two lines, and two distances" for "keyhole" localization theory, that is we use the baseline between the infraorbital margin and superior margin of the external acoustic meatus and the perpendicular line to the baseline through the top point of the digastric groove to establish a coordinate system. And the drilling point was 14.0 mm above and 6.5 mm behind the top point of the digastric groove in the coordinate system.

Maternal exposure to low-dose bisphenol A and its potential neurotoxic impact on male pups: A histological, immunohistochemical, and ultrastructural study.

BACKGROUND: Bisphenol A (BPA) is a widely used chemical with a harmful effect on animal and human. The neonatal and juvenile period is a highly risky neurodevelopmental period. AIM: This study aimed to determine how male albino rat pups' cerebral cortex was altered by low doses of BPA given to mothers and the role of the oxidative stress. METHODS: Thirty pregnant rats were randomly split into three equal groups, negative control, and positive control: received 1 cc of corn oil once a day through gastric tube and BPA treated: a dose of 200 µg/kg/day (dissolved in 1 cc corn oil). The male rat pups of each group were sacrificed at 1 week, 3 weeks and 6 weeks. The cerebra were then separated from the brain for histological and biochemical studies. RESULTS: Rats administered BPA had raised levels of lipid peroxidation marker (MDA), lower levels of enzymatic antioxidants (SOD and CAT) with decreased body, cerebral weights, and decreased levels of non-enzymatic antioxidant defense (GSH). Histo-pathologically, shrunken pyramidal cells with congested blood vessels appeared. GFAP displayed increased number of positive immune-reactive astrocytes with high statistically significant increase in the area % in BPA treated group when compared to the control groups, on contrary to MBP. Semi-thin and ultra-thin BPA-sections revealed degenerative changes in myelinated axons with tiny nucleus and broken nuclear membranes. Lysosomes, dilated endoplasmic reticulum cisternae with noticeable increase in unmyelinated nerve fibers were also observed. CONCLUSION: The structure of the developing cerebral cortex is negatively impacted by BPA due to oxidative stress.

The Impact of Chemical Fixation on the Microanatomy of Mouse Organotypic Hippocampal Slices.

Chemical fixation using paraformaldehyde (PFA) is a standard step for preserving cells and tissues for subsequent microscopic analyses such as immunofluorescence or electron microscopy (EM). However, chemical fixation may introduce physical alterations in the spatial arrangement of cellular proteins, organelles, and membranes. With the increasing use of super-resolution microscopy to visualize cellular structures with nanometric precision, assessing potential artifacts, and knowing how to avoid them, takes on special urgency. We addressed this issue by taking advantage of live-cell super-resolution microscopy that makes it possible to directly observe the acute effects of PFA on organotypic hippocampal brain slices, allowing us to compare tissue integrity in a "before-and-after" experiment. We applied super-resolution shadow imaging (SUSHI) to assess the structure of the extracellular space (ECS) and regular super-resolution microscopy of fluorescently labeled neurons and astrocytes to quantify key neuroanatomical parameters. While the ECS volume fraction (VF) and microanatomic organization of astrocytes remained largely unaffected by the PFA treatment, we detected subtle changes in dendritic spine morphology and observed substantial damage to cell membranes. Our experiments show that PFA application via immersion does not cause a noticeable shrinkage of the ECS in hippocampal brain slices maintained in culture, unlike the situation in transcardially perfused animals in vivo where the ECS typically becomes nearly depleted. Our study outlines an experimental strategy to evaluate the quality and pitfalls of various fixation protocols for the molecular and morphologic preservation of cells and tissues.

SR-CycleGAN: super-resolution of clinical CT to micro-CT level with multi-modality super-resolution loss.

Purpose: We propose a super-resolution (SR) method, named SR-CycleGAN, for SR of clinical computed tomography (CT) images to the micro-focus x-ray CT CT ( µ CT ) level. Due to the resolution limitations of clinical CT (about 500 × 500 × 500 µ m 3 / voxel ), it is challenging to obtain enough pathological information. On the other hand, µ CT scanning allows the imaging of lung specimens with significantly higher resolution (about 50 × 50 × 50 µ m 3 / voxel or higher), which allows us to obtain and analyze detailed anatomical information. As a way to obtain detailed information such as cancer invasion and bronchioles from preoperative clinical CT images of lung cancer patients, the SR of clinical CT images to the µ CT level is desired. Approach: Typical SR methods require aligned pairs of low-resolution (LR) and high-resolution images for training, but it is infeasible to obtain precisely aligned paired clinical CT and µ CT images. To solve this problem, we propose an unpaired SR approach that can perform SR on clinical CT to the µ CT level. We modify a conventional image-to-image translation network named CycleGAN to an inter-modality translation network named SR-CycleGAN. The modifications consist of three parts: (1) an innovative loss function named multi-modality super-resolution loss, (2) optimized SR network structures for enlarging the input LR image to 2 k -times by width and height to obtain the SR output, and (3) sub-pixel shuffling layers for reducing computing time. Results: Experimental results demonstrated that our method successfully performed SR of lung clinical CT images. SSIM and PSNR scores of our method were 0.54 and 17.71, higher than the conventional CycleGAN's scores of 0.05 and 13.64, respectively. Conclusions: The proposed SR-CycleGAN is usable for the SR of a lung clinical CT into µ CT scale, while conventional CycleGAN output images with low qualitative and quantitative values. More lung micro-anatomy information could be observed to aid diagnosis, such as the shape of bronchioles walls.

Usefulness of X-ray dark-field imaging in the evaluation of local recurrence after nipple-sparing mastectomy.

PURPOSE: Our previous study suggests that the cross-sectional morphology of ducts and branching of ducts in the nipple are associated with the presence of breast cancer. In this study, we evaluated whether cross-sectional morphology and duct branching of human nipple obtained by X-ray dark-field imaging tomographic technique (XDFI-CT) could predict the likelihood of the presence of intraductal cancer into the nipple. METHODS: A total of 51 nipple specimens were obtained from consecutive total mastectomies performed for breast cancer in Nagoya Medical Center. After reconstructing 3D images of the nipple using XDFI-CT, the cross-sectional images and the 3D arrangement of ducts were extracted. These cross-sectional images of ducts were classified into four patterns based on the status of the lumen without being informed of pathology results. RESULTS: Of the four patterns, the distended ducts with heterogenous content were highly correlated with the presence of ductal carcinoma in situ confirmed by histopathology. The total number of orifices identified in the 51 specimens was 1298, and 182 (14%) at the tip and 19 (1.5%) at least 5 mm depth from the tip were composed of two or more ducts. CONCLUSIONS: Anatomy of nipple ducts is essential to evaluate risk of local recurrence after nipple-sparing mastectomy because cancerous spread occurs within the duct of the same segment of the mammary duct-lobular system in the in situ stage. The 3D microscale anatomy of nipple ducts revealed by XDFI-CT provides useful information to assess the risk of breast cancer involvement at the preserved portion in nipple-sparing mastectomy.

Micro-anatomical structures of the lumbar intervertebral foramen for full-endoscopic spine surgery: review of the literatures.

Percutaneous endoscopic lumbar discectomy (PELD) is a minimally invasive spinal surgical technique. PELD can be performed via 2 routes, transforaminal (TF) or interlaminar. The TF approach is a well-established modality in the treatment of patients with herniated lumbar discs. This technique makes the most of the space within the intervertebral foramen where, as Kambin claimed, the safe approach to the lesion is possible. Knowledge of the lumbar artery with its branches and various ligaments of anatomies of the intervertebral foramen are needed to perform successful surgeries and to reduce complications.

A comparative histological study of the tongue of rat (Rattus norvegicus), bat (Eidolon helvum) and pangolin (Manis tricuspis) / Estudio histológico comparativo de la lengua de rata (Rattus norvegicus), murciélago (Eidolon helvum) y pangolín (Manis tricuspis)

This study assessed the micro anatomical differences in the tongue of rat, bat and pangolin with a view to establishing the functional anatomical differences of these mammalian tongues on their dietary pattern. Ten rats, ten bats and ten pangolins were used for this study. The animals were sacrificed and the tongue excised and processed for light microscopical study adopting the following stains: Haematoxylin Eosin, Verhoeff Gieson and Masson trichrome. The results showed non papillation of the keratinized stratified epithelium of pangolin tongue unlike the papillation seen in the tongue of the rat and bat. While the filiform papillation seen in the rat was bristle like, the filiform papillae in the bat were crown-like. There was also an unusual dense collagenous ring in the proximal portion of the pangolin tongue which was absent in other mammals. There were taste buds along the lateral walls of the vallate papillae in the distal portion of the tongue of rats and bats but none was found in the pangolins. In conclusion, the morphology of the tongues of these mammals showed a relationship between their feeding pattern and the adaptive changes in the microanatomy of their tongue.

Se evaluó los aspectos micro-anatómicos de la lengua de la rata, murciélago y pangolín, con miras a establecer las diferencias funcionales anatómicas de las lenguas de estos mamíferos en su patrón alimentario. Diez ejemplares de cada animal se utilizaron para este estudio. Los animales fueron sacrificados y las lenguas fueron extirpadas y procesadas para el estudio microscópico de luz, usándose las tinciones: Hematoxilina Eosina, Verhoeff Gieson y tricrómico de Masson. Los resultados mostraron la no papilación del epitelio estratificado queratinizado de la lengua de pangolines a diferencia de la papilación vista en la lengua de la rata y del murciélago. Por otro lado, las papilas filiformes vistas en la rata se presentaban como puntas, siendo como coronas en el murciélago. También hubo un inusual anillo de colágeno denso en la porción proximal de la lengua de pangolines, estando ausente en los otros mamíferos. Se observaron botones gustativos a lo largo de las paredes laterales de las papilas caliciformes en la porción distal de la lengua de las ratas y los murciélagos, pero ninguno fue encontrado en la de los pangolines. En conclusión, la morfología de las lenguas de estos mamíferos mostró una relación entre su patrón de alimentación y los cambios de adaptación en la anatomía microscópica de la lengua.

A glandula ectodermal do aparelho copulador do Triatoma Infestans (Heteroptera, Triatominae)

Descreve-se a microanatomia e citologia de uma glândula localizada na aparelho copulador masculino de Triatoma infestans. A glândula compõe-se de duas áreas de células hipodérmicas glandulares e células hipodérmicas não modificadas, porém sinciciais, situadas nos dois lados da membrana intersegmental entre os oitavo e nono segmentos. As células representam um tipo de células glandulares bem desenvolvido, caracterizado por sua separação da cutícula por um aparelho excretor-condutor com canal cuticular e zona radiata bem desenvolvida e pelo início da formação de um complexo glandular fechado.