Quantitative anatomy of the fused ossification center of the occipital squama in the human fetus

Quantitative anatomy of the primary ossification center of the squamous part of temporal bone in the human fetus

Detailed numerical data about the development of primary ossification centers in human fetuses may influence both better evaluation and early detection of skeletal dysplasias, which are associated with delayed development and mineralization of ossification centers. To the best of our knowledge, this is the first report in the medical literature to morphometrically analyze the primary ossification center of the squamous part of temporal bone in human fetuses based on computed tomography imaging. The present study offers a precise quantitative foundation for ossification of the squamous part of temporal bone that may contribute to enhanced prenatal care and improved outcomes for fetuses with inherited cranial defects and skeletodysplasias. The examinations were carried out on 37 human fetuses of both sexes (16 males and 21 females) aged 18-30 weeks of gestation, which had been preserved in 10% neutral formalin solution. Using CT, digital image analysis software, 3D reconstruction and statistical methods, the size of the primary ossification center of the squamous part of temporal bone was evaluated. With neither sex nor laterality differences, the best-fit growth patterns for the primary ossification center of the squamous part of temporal bone was modelled by the linear function: y = -0.7270 + 0.7682 × age ± 1.256 for its vertical diameter, and the four-degree polynomial functions: y = 5.434 + 0.000019 × (age)4 ± 1.617 for its sagittal diameter, y = -4.086 + 0.00029 × (age)4 ± 2.230 for its projection surface area and y = -25.213 + 0.0004 × (age)4 ± 3.563 for its volume. The CT-based numerical data and growth patterns of the primary ossification center of the squamous part of temporal bone may serve as age-specific normative intervals of relevance for gynecologists, obstetricians, pediatricians and radiologists during screening ultrasound scans of fetuses. Our findings for the growing primary ossification center of the squamous part of temporal bone may be conducive in daily clinical practice, while ultrasonically monitoring normal fetal growth and screening for inherited cranial faults and skeletodysplasias.

Preservation fluids of heritage anatomical specimens - a challenge for modern science. Studies of the origin, composition and microbiological contamination of old museum collections

Anatomical museums preserve specimens of great historical value and undiscovered scientific potential. However, frequently these collections lack documentation of the techniques of preparation and the composition of preservative substances (conservation principles). This poses a huge problem for the care and preservation of these materials, more so because understanding this issue requires knowledge of fundamentals from different scientific disciplines. The aim of the research was to obtain information about the composition of substances used to preserve historic specimens, as well as to conduct a microbiological assessment of the specimens to detect possible factors causing their deterioration. Furthermore, we wanted to fill an existing gap in the literature, as there is a lack of reports on analytical methods that could be successfully applied by anatomists involved in the daily care of museum collections in human anatomy departments. The starting point was the analysis of the sources and history of the collections, on which basis the choice of research methods was made. Methods based on simple chemical reactions and specialised methods (such as gas chromatography-tandem mass spectrometry, Fourier transform infrared spectroscopy, inductively coupled plasma optical emission spectroscopy) were used in the analyses of the composition of fluids. Microbiological analyses were based on culture and isolation methods, analysis of microscopy slides and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry analysis. As a result of these analyses, some components of the preservative mixtures and their concentrations were determined. The presence of methanol, ethanol, formaldehyde and glycerol was detected, among other chemicals. The concentrations of these substances were different between the samples and their determination required the use of a variety of methods suitable for the individual components of the preservative mixture. In microbiological tests, both bacteria and fungi were isolated from swabs taken from anatomical specimens. The bacterial flora was less numerous than the fungal flora. Among the bacteria, environmental Gram-positive Bacillus cereus, Bacillus thuringiensis and a rare bacterium of the Cupriavidus genus were isolated, whereas among the fungal organisms, the yeast-like fungi Candida boidinii and Geotrichum silvicola as well as mould fungi Penicillium sp. and Fusarium sp. were detected. However, the microscopic evaluation showed a greater diversity of microorganisms, which may be related to the fact that many environmental bacteria cannot be cultured using classical methods, but can be observed under the microscope. The results of the research made it possible to draw conclusions about the mutual influence of physical, chemical, and microbiological factors on the condition of historical anatomical specimens. In the course of the research, information was obtained on the processes which could have taken place during the storage of these collections. Maintaining the integrity of a container housing a preserved anatomical specimen has a major impact on maintaining the concentration of preservative fluid and keeping the specimen environment sterile. Many conservation procedures for historical specimens carried out nowadays pose a risk of destroying valuable specimens, as well as a health risk for the person carrying out the work. The exploration of the topic of conservation of anatomical specimens, especially those that lack documentation of their origin, is a key issue in current research on historical collections of anatomical specimens.

Emissary Foramina of the External Occipital Protuberance: A Magnetic Resonance Imaging Study

OBJECTIVE

The posterior interparietal region is known to be a distinct area of the skull, predisposing to a variety of bony variants and congenital anomalies. The bony canals in this region have not yet been explored in detail. This study aimed to characterize them.

PATIENTS AND METHODS

Overall, 82 patients underwent thin-slice contrast magnetic resonance imaging. Coronal and sagittal images were used for the analysis.

RESULTS

At the rostral limit of the posterior interparietal region, the parietal foramen (PF) and transmitting emissary vessels were identified in 84% of cases, mostly delineated as single channels. They were located in the left parasagittal region (PS) in 26%, lateral to the left PS in 33%, right PS in 40%, lateral to the right PS in 12%, and midline in 16% of the cases. In 4% of the cases, the PF presented an obstruction around the outer opening. In the more caudal part of the posterior interparietal region, 51% of the patients presented with fine bony canals and transmitting emissary vessels, lying in the midline and parasagittal levels.

CONCLUSIONS

The frequency of PFs may be underestimated for superficially hidden outer openings of the canals. The midline posterior interparietal region may present fine bony canals for transmitting emissary vessels that function complementarily with PFs.