Cranial Region Research Articles

Computed Tomography Anatomy of the Juvenile Cory's Shearwater (Calonectris borealis) Normal Nasal Cavity.

We conducted a detailed examination of the anterior cranial region of Cory's Shearwater (Calonectris borealis), employing cutting-edge imaging techniques and computed tomography (CT). The fusion of CT images with anatomical cross-sectional data played a pivotal role in providing a thorough depiction of the components constituting the anterior cranial region of this species. The explication of these structures holds significant potential as an essential procedure for the prognosis and management of diverse pathologies impacting the nasal cavity of Cory's Shearwater.

Comparative study of the histology and Micro-CT scan of the goldfish hood

The hood (also known as head growth or wen) is a distinctive feature of goldfish characterized by skin tissue proliferation. The classification of goldfish hood types and the study of the underlying skeletal structure still have substantial gaps in research. This study aimed to investigate the structural differences in goldfish hood tissues using histological and Micro-CT comparisons, based on traditional Chinese classifications. Histological observations revealed two distinct types: the one-piece type (Crown Pearlscale), characterized by a uniformly thickened epidermis, and the fused type (Oranda, Red Cap Oranda, and Ranchu), which showed irregular epidermal extensions into the dermis. Micro-CT scans further demonstrated that hooded goldfish exhibited skull protrusions, bone spurs, and widening of the cranial region. These findings indicate that fibroblast activity, tissue edema, and bone structural changes may be key drivers of hood formation in these goldfish varieties.

Observations on the reproductive morphology of the female short-beaked echidna, Tachyglossus aculeatus.

Although monotremes diverged from the therian mammal lineage approximately 187 million years ago, they retain various plesiomorphic and/or reptilian-like anatomical and physiological characteristics. This study examined the morphology of juvenile and adult female reproductive tracts across various stages of the presumptive oestrous cycle, collected opportunistically from cadaver specimens submitted to wildlife hospitals during the breeding season. In adult females, ovaries had a convoluted cortex with follicles protruding from the ovarian surface. While protruding antral follicles were absent from the ovaries of juvenile echidnas, histological analysis identified early developing primordial and primary follicles embedded into the ovarian cortex. The infundibulum epithelial cells of the oviducts were secretory during the follicular phase but not at other stages, the ampulla region was secretory at all stages and is likely responsible for the mucoid layer deposited around the zona pellucida, and the isthmus region of the oviduct appeared to be responsible for initial deposition of the shell coat, as in marsupials. Female echidnas have two separate uteri, which never merge and enter separately into the urogenital sinus (UGS). This study confirmed that both uteri are functional and increase in glandular activity during the luteal phase. In the juvenile uteri, the endometrium was immature with minimal, small uterine glands. A muscular cervical region at the caudal extremity of each uterus, just before the cranial region of the UGS was defined by the absence of glandular tissue in all female echidnas, including the juveniles. There was no evidence of a definitive vaginal region. A clitoris was also detected that possessed a less developed but similar structural (homologous) anatomy to the male penis; urethral ducts while present did not appear to be patent.

Distribution of mechanical properties of native human ligamentum flavum depending on histopathological changes

This study aimed to characterize the mechanical properties of native human ligamentum flavum (LF) and correlate them with histopathological changes. Mechanical property gradients across the cranial, medial, and caudal regions of LF were mapped and compared with histological sections. We also compared lumbar spinal stenosis (LSS) samples with disc herniation (DH) samples as reference material to identify differences in mechanical properties and histopathological features. Our results revealed significant heterogeneity in LF mechanical properties, with local variations correlating with specific histopathological changes such as chondroid metaplasia and loss of elastic fibers. These findings underscore the importance of considering LF heterogeneity in mechanical characterization and provide insights into its behavior under pathological conditions.

Early Bone and Suture Reformations in Different Cranial Regions After Cranial Vault Remodeling for Sagittal Craniosynostosis.

Cranial vault remodeling (CVR) is a common procedure for correcting sagittal craniosynostosis. Some approaches leave significant craniectomy defects. The authors investigated the reosteogenesis in different cranial defect areas after CVR. A cross-sectional study was conducted in nonsyndromic sagittal craniosynostosis. Available early postoperative computed tomography (CT) scans were analyzed. The segmentation of three-dimensional reconstructed images was performed. Different cranial defect areas, including coronal, vertex, and occipital regions, were further investigated using an automated three-dimensional analysis software for reosteogenesis percentage. Forty-four CT scans were included. The average age at CVR was 8.8 months. The median time of postoperative CT scans was 6.1 weeks. The median bone reformation percentage of the entire cranial defect was 56.7%. Given the similar postoperative CT timing, the median bone reformation at the coronal, vertex, and occipital areas demonstrated 44.21%, 41.13%, and 77.75%, respectively (P < 0.001). In the simultaneously removed coronal and lambdoid sutures, there were 45% with coronal and lambdoid sutures reformation, followed by lambdoid suture reformation alone, no suture reformation and coronal reformation alone in 35%, 20%, and 0%, respectively (P = 0.013). There was no coronal reformation in the removed coronal suture group. However, 40% demonstrated lambdoid suture reformation after the isolated lambdoid suture removal. The occipital region has the highest reosteogenesis compared with the other cranial defects after CVR in nonsyndromic sagittal craniosynostosis. Within the removed previous patent sutures, the lambdoid suture reformation showed a higher rate than the coronal suture.

Analysis of Three-Dimensional Tooth Movement: A Comparative Study Between Digital Dental Models and Craniofacial Models.

This study aims to validate the efficacy of using a digital dental model (DM) with reference to the palatal region of interest (PROI) for assessing orthodontic tooth movement (TM)by comparing it with the analysis of a computed tomography (CT) model with reference to the cranial region of interest (CROI). Thirty-four patients (mean age: 21 years and 11 months) with jaw deformities underwent DM and CT scans before and after presurgical orthognathic treatment. Linear and angular measurements during TM were conducted in three dimensions using both DM and CT to assess reliability. DM analysis with PROI registration exhibited high levels of reproducibility, with minimal standard errors in X, Y, and Z displacements (<0.15 mm) and 0.43 degrees in angular change. CT analysis with CROI registration demonstrates similarly high reproducibility, with standard errors inferior to DM analysis (<0.20 mm). Bland-Altman analysis indicated agreement in linear changes of each X, Y, and Z displacement between DM and CT measurements, with limits of agreement (LOA) below 0.91 mm. The results of this study suggest that the PROI, focusing on the third palatal rugae and the horizontal part of the palatal vault, serves as a reliable reference region for evaluating three-dimensional (3D) tooth movement. Digital dental models offer distinct advantages including the absence of X-ray exposure, no metal artifacts, and the ability to generate high-resolution 3D models. The methodology demonstrated high precision and reproducibility, supporting its potential clinical utility in orthodontic treatment planning and assessment.

Biportal Endoscopic TransOrbital and transMaxillary Approach to the Cranio-Orbital Region and Middle Cranial Fossa: A Preliminary Analysis of Maneuverability.

Traditional and well-established transcranial approaches to the spheno-orbital region and middle cranial fossa guarantee optimal intracranial exposure, and additional orbital and zygomatic osteotomies provide further control over extracranial components to be resected; however, these techniques come at the cost of additional morbidity. The introduction of minimally invasive endoscopic approaches and the conceptualization of the so-called "multiportal" paradigm might provide an alternative route. This preliminary study investigates the feasibility of the combined Biportal Endoscopic TransOrbital and transMaxillary Approach (bETOMA) approach to the spheno-orbital and middle cranial fossa regions. Using 4 silicon-injected adult cadaver heads (8 sides; 16 approaches), we systematically dissected through superior eyelid ETOA and endoscopic TMA approaches. The analysis focused on pterygopalatine, infratemporal, anterior and middle cranial fossae, Meckel cave, and cavernous sinus access. We evaluated the feasibility of bETOMA using linear distances, angles of attack, and exposure areas. We also introduced volume of operative maneuverability, its standardized derivative (sVOM), target distance, visuo-operative angle, and working zone volume as novel metrics. The analysis revealed comparable angles of attack between approaches. ETOA and TMA exposure areas were 918.38 ± 223.93 mm2 and 257.07 ± 86.07 mm2, respectively. TMA showed a larger VOM in the greater sphenoid wing, but ETOA offered superior distal maneuverability (sVOM: 5.39 ± 1.94 vs 2.54 ± 0.79 cm3) and closer intracranial space access (27.45 vs 50.83 mm). The combined approaches yielded a mean working zone volume of 13.75 ± 3.73 cm3 in the spheno-orbital interface. The bETOMA approach provides adequate neurovascular exposure and maneuverability to the spheno-orbital region, infratemporal, and anterior and middle cranial fossae, addressing significant limitations of previously investigated monoportal techniques (ie, optic nerve decompression, hyperostotic bone resection, and infratemporal exposure). This combined minimally invasive approach might help manage lesions harbored within the cranio-orbital interface region invading the extracranial space.

Characterization of internal jugular vein region-specific distension and flow patterns during progressive volume shifting.

Blood volume shifts during postural adjustment leads to irregular distension of the internal jugular vein (IJV). In microgravity, distension may contribute to flow stasis and thromboembolism, though the regional implications and associated risk remain unexplored. We characterized regional differences in IJV volume distension and flow complexity during progressive head-down tilt (HDT) (0°, -6°, -15°, -30°) using conventional ultrasound and vector flow imaging. We also evaluated low-pressure thigh cuffs (40 mmHg) as a fluid shifting countermeasure during -6° HDT. Total IJV volume expanded 139±95% from supine (4.6±2.7 mL) to -30° HDT (10.3±5.0 mL). Blood flow profiles had greater vector uniformity at the cranial IJV region (P<0.01) and became more dispersed with increasing tilt (P<0.01). Qualitatively, flow was more uniform throughout the IJV during its early flow cycle phase, and more disorganized during late flow phase. This disorganized flow was accentuated closer to the vessel wall, near the caudal region, and during greater HDT. Low-pressure thigh cuffs during -6° HDT decreased IJV volume at the cranial region (-12±15%; P<0.01) but not the caudal region (P=0.20), although flow uniformity was unchanged (both regions,P>0.25). We describe a distensible IJV accommodating large volume shifts along its length. Prominent flow dispersion was primarily found at the caudal region, suggesting multi-directional blood flow. Thigh cuffs appear effective for decreasing IJV volume but effects on flow complexity are minor. Flow complexity along the vessel length is likely related to IJV distension during chronic volume shifting and may be a precipitating factor for flow stasis and future thromboembolism risk.

Occurrence pattern of diaphragmatic hernia in bovines

The present study was done with an objective to evaluate the occurrence pattern of diaphragmatic hernia in Bovines. All the bovines presented with and positive for diaphragmatic hernia (n=162) on radiography or ultrasonography were included in the study period of 15 months. The overall hospital and radiographic occurrence of diaphragmatic hernia in bovines was 2.22% and 11.96% respectively. The highest radiographic occurrence of DH was in the month of December (21.21%) followed by in February (20.41%) and the least was in September (0.89%).The study included 159 buffaloes and 3 cows. Among buffaloes, 2 were males (1.26%) and the rest females. All the cows presented were females; 2 cows were of indigenous Sahiwal breed, and one was a Jersy cross bred. Most of the bovines (72.22%) were presented in a period of 8 to 30 days of appearance of clinical signs. The average age of bovines presented was 5.87±2.21 (2-14) years, body weight 391.39±69.72 (204-560) kg, Body condition score 1.69±0.67 (1-3.5), in-appetence in 96.30%, recurrent bloat in 67.29%, hard black scanty faeces in 85.80%, occasional coughing in 9.87% and mild brisket oedema in 4.94%. The 40.74% of bovines were non-pregnant (with 28.79% recently parturited) and 59.26% (with 38.64% in advance pregnancy) were in some stage of pregnancy. The average heart rate of bovines was 72.08±16.31 (43-120) beats/min, respiration rate 22.52±11.31 (5-60)/minute and temperature 100.43±1.88 (95-106)°F. Most of the bovines (82.10%) were active and alert with pink mucous membrane (59.29%), one was presented recumbent and 17.28% were dull and depressed. The average haemoglobin in g% was 10.38±2.41 (3.5-17.4) with maximum bovines had haemoglobin between 10 to 12 g% (37.24%). Only 67% bovines had potential foreign bodies in cranial or caudal reticular regions on recumbent radiography.In conclusion, the radiographic occurrence of diaphragmatic hernia in buffaloes is alarming; however, the cows and male buffaloes are rarely reported. The existence of DH in indigenous cows is reported. The young adult female buffaloes are maximum susceptible to the disease condition of diaphragmatic hernia. Reduced BCS and body weight due to chronic in appetence is characteristic of non-pregnant diaphragmatic hernia Bovines. Passage of hard scanty faeces and in-appetence was a characteristic of the condition, however, recurrent bloat, advance pregnancy and presence of potential foreign body on radiograph was not a characteristic feature of diaphragmatic hernia in bovines.

A novel approach to craniofacial analysis using automated 3D landmarking of the skull

Automatic dense 3D surface registration is a powerful technique for comprehensive 3D shape analysis that has found a successful application in human craniofacial morphology research, particularly within the mandibular and cranial vault regions. However, a notable gap exists when exploring the frontal aspect of the human skull, largely due to the intricate and unique nature of its cranial anatomy. To better examine this region, this study introduces a simplified single-surface craniofacial bone mask comprising of 6707 quasi-landmarks, which can aid in the classification and quantification of variation over human facial bone surfaces. Automatic craniofacial bone phenotyping was conducted on a dataset of 31 skull scans obtained through cone-beam computed tomography (CBCT) imaging. The MeshMonk framework facilitated the non-rigid alignment of the constructed craniofacial bone mask with each individual target mesh. To gauge the accuracy and reliability of this automated process, 20 anatomical facial landmarks were manually placed three times by three independent observers on the same set of images. Intra- and inter-observer error assessments were performed using root mean square (RMS) distances, revealing consistently low scores. Subsequently, the corresponding automatic landmarks were computed and juxtaposed with the manually placed landmarks. The average Euclidean distance between these two landmark sets was 1.5 mm, while centroid sizes exhibited noteworthy similarity. Intraclass coefficients (ICC) demonstrated a high level of concordance (> 0.988), with automatic landmarking showing significantly lower errors and variation. These results underscore the utility of this newly developed single-surface craniofacial bone mask, in conjunction with the MeshMonk framework, as a highly accurate and reliable method for automated phenotyping of the facial region of human skulls from CBCT and CT imagery. This craniofacial template bone mask expansion of the MeshMonk toolbox not only enhances our capacity to study craniofacial bone variation but also holds significant potential for shedding light on the genetic, developmental, and evolutionary underpinnings of the overall human craniofacial structure.

Use of tie-in femur osteosynthesis in free-living aracuã scamoso (ortalis squamata) with blockage of the femoral and ischiatic nerves

We report the case of an adult scaly-breasted arachnid, which arrived for treatment with a history of being on the ground in the courtyard of a house, unable to stay in a station. On clinical examination, the bird had an immobile right femur, with a probable comminuted fracture, and the decision was made to perform a surgical procedure to correct the fracture. The treatment used the tie-in technique, where a 1.2 mm intramedullary pin was placed in the femur for initial alignment of the bone fragments, while external fixation was carried out with three pins of the same thickness as the previous one, two in the cranial region and one in the region distal to the fracture site. Two months after the surgery, an X-ray was taken to check for the formation of bone callus, with a satisfactory result. The external fixator was removed the following day, and seven days after removal the bird was discharged and released. As well as the tie-in technique having a high success rate with a complete return of function, it has the advantage that its implants are removable, which is important when the animal is returned to the wild, preventing these implants from remaining in the environment if it dies.

Analysis of clinical manifestations and imaging features of facial nerve schwannomas

Objective:To explore the clinical manifestations and imaging characteristics, and to clarify the imaging value in the diagnosis of facial nerve schwannomas. Methods:Retrospectively analyze the data of 23 patients with facial nerve schwannomas confirmed by surgery and pathology in the Department of Otorhinolaryngology of the First Affiliated Hospital of the Air Force Military Medical University from September 2020 to September 2022, including 8 males and 15 females, aged 18-66 years old. Summarize and analyze their clinical symptoms, specialized examinations, and imaging findings. Results:The clinical manifestations were facial nerve paralysis in 15 cases（2 cases of HB Ⅳ, 6 cases of HB Ⅴ, 7 cases of HB Ⅵ）, hearing loss in 14 cases（5 cases of conductive deafness, 2 cases of mixed deafness, and 7 cases of severe sensorineural hearing loss）, 8 cases tinnitus, 7 cases ear pain, 4 cases dizziness, 4 cases headache, 2 cases ear pus, and parotid gland tumors in 6 cases presenting as local masses. Endoscopic examination revealed 8 cases of external ear canal tumors and 3 cases of intratympanic tumors. Combining temporal bone HRCT, MRI enhanced scanning, and CPR imaging techniques, 1 case involved the internal auditory canal segment, 2 cases in the tympanic segment, 6 cases in the parotid gland area. A total of 14 cases involved two or more segments of the internal auditory canal segment, the labyrinthine segment, geniculate ganglion, the tympanic segment, and the mastoid segment. When the tumors were large, adjacent structures were involved. It was found that 8 cases invaded the external auditory canal and tympanic cavity, ossicles were displaced or bony destruction; 3 cases invaded the jugular foramen area, and 1 case grew to the middle cranial fossa region with temporal lobe brain parenchymal compression. Conclusion:The clinical manifestations of facial nerve schwannomas are diverse. The combination of various imaging techniques will be conducive to topical and qualitative diagnosis and provide an important basis for treatment strategies.

Exploration of postural effects on the external jugular and diploic venous system using upright computed tomography scanning.

Few studies have investigated the influence of posture on the external jugular and diploic venous systems in the head and cranial region. In this study, we aimed to investigate the effects of posture on these systems using upright computed tomography (CT) scanning. This study retrospectively analysed an upright CT dataset from a previous prospective study. In each patient, the diameters of the vessels in three external jugular tributaries and four diploic veins were measured using CT digital subtraction venography in both supine and sitting positions. Amongst the 20 cases in the original dataset, we eventually investigated 19 cases due to motion artifacts in 1 case. Compared with the supine position, most of the external jugular tributaries collapsed, and the average size significantly decreased in the sitting position (decreased by 22-49% on average). In contrast, most of the diploic veins, except the occipital diploic veins, tended to increase or remain unchanged (increased by 12-101% on average) in size in the sitting position compared with the supine position. However, the changes in the veins associated with this positional shift were not uniform; in approximately 5-30% of the cases, depending on each vein, an opposite trend was observed. Compared to the supine position, the contribution of external jugular tributaries to head venous drainage decreased in the sitting position, whilst most diploic veins maintained their contribution. These results could enhance our understanding of the physiology and pathophysiology of the head region in upright and sitting positions.

Volumetric assessment of Posterior cranial fossa in a West African population

Background and Objectives: Posterior fossa pathologies can have potentially devastating outcomes. The volumetric capacity of this fossa, known to have ethnoregional variations, can thus be critical in determining outcomes and intervention measures and approaches to pathologies involving this region. This study aimed to evaluate the normal posterior fossa volumes within the West-African subpopulation. Methods: This was a descriptive study of all patients presenting for a cranial imaging study at the study location within a two-year period using a 1.5T MRI of this cranial region. Obtained data included the transverse and anteroposterior diameters, and the height of this fossa and the obtained data was analyzed. P values < 0.05 was statistically significant. Results: A total of 315 patients were recruited (165 males and 150 females). The average posterior fossa transverse diameter, anteroposterior diameter and height were 108.19 mm, 71.58 mm and 35.53 mm respectively for males, and 105.7 mm, 66.48 mm, and 34.24 mm for females respectively. The average posterior fossa volume for males (292.36 cm3) was significantly higher than for females (252.90 cm3) (p= 0.0038). The highest average posterior fossa volume was between 16-30 years for males and above 75 years for females. Conclusion: Posterior cranial fossa volumes for the West African population is significantly higher than those obtained for other regions. In addition to being beneficial in some posterior fossa space occupying lesions, this larger volume can explain the relative rarity and sexual preferences of some posterior fossa congenital abnormalities like Chiari-1 malformation amongst the West African population

Myoid gonadal stromal tumor of the testis—the novel subtype of testicular gonadal stromal tumors: a case report and review of the literature

BackgroundSex cord gonadal stromal tumors compose less than 10% of all testicular neoplasms and consist of a variety of histological subtypes. In 2016, the World Health Organization introduced a novel subtype, the myoid gonadal stromal tumor, that consists of spindle-shaped cells with immunohistologic features of muscle cells. Only few cases have been reported to date. Due to its rarity and owing to its only recent introduction, the current knowledge about myoid gonadal stromal tumor is limited, and particularly, appropriate clinical management is still ill-defined.Case presentationA 47-year-old man of Caucasian descent presented with nonspecific scrotal discomfort. A roundish and well demarcated hypoechoic mass of 8.5 mm in diameter was detected in the cranial region of the left testis. Serum tumor marker levels were within normal ranges. Testis-sparing surgery revealed a 9-mm whitish, hard mass with sharp surgical margin. Histologically, the neoplasm consisted of microfibrillar tissue with spindle-shaped cells harboring elongated nuclei. Immunohistochemical work-up disclosed expression of desmin, small muscle actin, and S100 protein giving evidence for the myogenic nature of the neoplastic cells. There was no indication of malignancy, neither histologically nor clinically. Follow-up of 1 year was uneventful.ConclusionA literature survey revealed 22 previous cases of myoid gonadal stromal tumor. The median age was 37 years, the median size of the neoplasm was 20 mm, and there was no side-preponderance. Myoid gonadal stromal tumor is not much different from other subtypes of gonadal stromal tumors nor from testicular gem cell tumors regarding age and laterality; however, tumor size is smaller in myoid gonadal stromal tumors than in germ cell tumors. Although rarely performed so far, testis-sparing surgery probably constitutes an appropriate treatment of this neoplasm. Myoid gonadal stromal tumor represents an emerging novel entity of benign testicular new growths that caregivers of patients with testicular tumors should be aware of.

Artificial insemination of all ejaculated sperm fractions accelerates embryo development and increases the uterine vascularity in the pig

The semen of boar is characterized by ejaculation in well-differentiated fractions with specific concentration, composition, and volume. The ‘sperm-rich fraction' (SRF), the most concentrated seminal fraction, is habitually collected in insemination centers to make artificial insemination (AI) doses. The absence of the other fractions in AI doses could alter the uterine reaction to AI and not trigger essential responses that could maximize fertility. Thus, there is an urge to ascertain the impact of different ejaculate fractions on the uterus after AI to optimize the semen doses. This work analyzed specific parameters related to fertility in pregnant artificially inseminated sows (n = 15) with ac-cumulative fractions of the semen of boars (n = 6): F1, composed of the sperm-rich fraction (SRF); F2, composed of F1 plus the intermediate fraction; F3, composed of F2 plus the post-SRF. Non-inseminated sows (n = 5) were included as control (C). The different types of seminal dose did not affect the number of ovulated follicles (CL; corpora lutea, p > 0.05) but did affect the embryo development (p < 0.05). The proportion of embryos in morula stages was significantly higher in AI-F1 sows (84.4%, p < 0.05). Morulas and blastocysts were balanced in AI-F2 or AI-F3 (p > 0.05). Independently of the type of seminal dose (F1, F2, or F3), we observed by immunohistochemistry that AI significantly increased uterine vascularization, although with some anatomical differences. The cranial region of the uterine horns was significantly more vascularized in AI-F1 or AI-F2 sows (26.7 ± 2.3 and 28.6 ± 2.0%, respectively), and AI-F3 showed significantly less vascularization at that point (17.8 ± 1.6%, p < 0.05). To summarize, the synergistic effect of all ejaculate fractions accelerates embryo development, at least during the preimplantation period, and increases the uterine reaction to AI in certain parts of the uterus.

Diagnostic approach of hydrocephaly in Shih-Tzu dogs - case report

The objective of this study was to describe the use of complementary imaging tests to aid diagnosis in cases of hydrocephalus in the canine species. A female canine, of the Shih-Tzu breed, approximately three months old, weighing 2 kg, was seen at the Unicentro veterinary school clinic, with the main complaint of not playing and not responding to auditory or visual stimuli. The patient had pain when palpated in the cranial region, as well as pain in the topography of the cervical spine. The animal was sent for imaging exam. On radiographic examination, an enlarged skull was observed with soft tissue radiopacity in the frontal bone area, associated with bone discontinuity in the anatomical topography of the frontal fontanelles. On transcranial ultrasound, anechoic areas located inside the brain were detected, as well as an increase in the dimensions of the lateral ventricles filled with anechoic content. The report was indicative of hydrocephalus. The present study showed the effectiveness of transcranial ultrasound examination and cranial radiographic examination in diagnosing hydrocephalus. Being an alternative to veterinarians, since computed tomography and magnetic resonance imaging are high-cost exams and these methods are often unavailable, depending on the region.

Effects of graded exercise load on variations of certain physiological parameters in Lipizzan horses during riding – a pilot study

Abstract Scientifically sound studies investigating the influence of riders on the physiological responses of riding horses are rare. Therefore, this pilot study was aimed to investigate the physiological changes in 6 purebred Lipizzan horses during an exercise test (ExT) in an indoor arena performed by a male and a female rider with different body weights and experience levels. Respiratory rate, rectal and body surface temperature, lactate, creatinine, and cortisol concentrations were measured before (BEx) and after exercise tests (AEx) with a graded workload, while heart rate and speed were recorded telemetrically during the ExT. Measured values were within a range for warm-blooded animals and increased significantly ( to ) in both riders AEx. BST values were highest in the cranial regions of the horses, followed by the caudal and distal body regions (). The differences in values were insignificant () between the two ExTs, except the higher heart rate between the male and the female rider (P &lt; 0.05). The results of this study indicate that there are no influences of rider characteristics on the physiological responses of riding horses and point to the importance of further research in the field of equine exercise testing, sports medicine, and animal welfare, which will also provide necessary knowledge for the conservation and development of the Lipizzan breed.

Evaluating the muscle attachment hypothesis for sagittal cresting in Gorilla and Pongo.

Primate mandibular morphology is often associated with jaw functionality of the masticatory complex in the context of variation in diets. Recent research into the disparities between the diet and jaw functionality in male and female hominoids is inconclusive and suggests that sexual dimorphism in the mandible may be influenced by external factors such as temporalis and masseter muscle morphology, which in turn may be influenced by sexual selection. As the muscles associated with mastication (i.e., the type of chewing exhibited by primates and other mammals) encompass the mandible as well as the neurocranium, including the sagittal crest among some individuals, this study investigates sex-specific associations between regions of the mandibular ramus and neurocranium associated with mastication in a dentally mature sample of Gorilla and Pongo. A total of four cranial and mandibular variables were measured in two Gorilla taxa (Gorilla gorilla gorilla and Gorilla beringei graueri) and one Pongo taxon (Pongo pygmaeus pygmaeus) (n = 220). For all three taxa, we investigate (a) whether the degree of sexual dimorphism in cranial regions associated with sagittal cresting (sagittal crest size (SCS) and temporalis muscle attachment area (TMAA)) is proportional to the degree of mandibular ramus area (MRA) and coronoid process height (CPH) sexual dimorphism, (b) whether there are sex differences in scaling relationships between TMAA and MRA, and (c) whether there are sex differences in the strength of association between TMAA and CPH. We show that for G. g. gorilla, variables associated with sagittal cresting show higher sexual dimorphism values than our two mandibular ramus variables, which is not the case for G. b. graueri or for P. p. pygmaeus. All three taxa show similar sex-specific scaling relationships between TMAA and MRA, where for males this relationship does not diverge from isometry, and for females there is a negative allometric relationship. Our findings also show intraspecific sex differences in allometric slopes between MRA and TMAA for all three taxa. Only G. g. gorilla shows a significant association between TMAA and CPH, which is observed in both sexes. Although there are some statistical associations between the cranial and mandibular regions associated with mastication, our results show that among male gorillas and orangutans, patterns of variation in the sagittal crest, TMAA, mandibular ramus and the coronoid process cannot be explained by the muscle attachment hypothesis alone. These findings have implications surrounding the associations between social behaviour and the morphology of the craniofacial complex.

Olivary body exposure through far lateral and lower retrosigmoid approaches. Comparative analysis of the exposed surface and angle of attack

ObjectivesThroughout neurosurgical history, the treatment of intrinsic lesions located in the brainstem has been subject of much controversy. The brainstem is the anatomical structure of the central nervous system (CNS) that presents the highest concentration of nuclei and fibers, and its simple manipulation can lead to significant morbidity and mortality. Once one of the safe entry points at the medulla oblongata has been established, we wanted to evaluate the safest approach to the olivary body (the most used safe entry zone on the anterolateral surface of the medulla oblongata). The proposed objective was to evaluate the working channel from the surface of each of the far lateral and retrosigmoid approaches to the olivary body: distances, angles of attack and channel content. Material and methodsTo complete this work, a total of 10 heads injected with red/blue silicone were used. A total of 40 approaches were made in the 10 heads used (20 retrosigmoid and 20 far lateral). After completing the anatomical study and obtaining the data referring to all the approaches performed, it was decided to expand the sample of this research study by using 30 high-definition magnetic resonance imaging of anonymous patients without cranial or cerebral pathology. The reference points used were the same ones defined in the anatomical study. After defining the working channels in each of the approaches, the working distances, angle of attack, exposed surface, and the number of neurovascular structures present in the central trajectory were analyzed. ResultsThe distances to the cranial and medial region of the olivary body were 52.71 mm (SD 3.59) from the retrosigmoid approach and 27.94 mm (SD 3.99) from the far lateral; to the most basal region of the olivary body, the distances were 49.93 (SD 3.72) from the retrosigmoid approach and 18.1 mm (SD 2.5) from the far lateral. The angle of attack to the caudal region was 19.44° (SD 1.3) for the retrosigmoid approach and 50.97° (SD 8.01) for the far lateral approach; the angle of attack to the cranial region was 20.3° (SD 1.22) for the retrosigmoid and 39.9° (SD 5.12) for the far lateral. Regarding neurovascular structures, the probability of finding an arterial structure is higher for the lateral far, whereas a neural structure will be more likely from a retrosigmoid approach. ConclusionsAs conclusions of this work, we can say that far lateral approach presents more favorable conditions for the microsurgical treatment of intrinsic bulbar and bulbomedullary lesions approached through the caudal half of the olivary body. In those cases of bulbar and pontine-bulbar lesions approached through the cranial half of the olivary body, the retrosigmoid approach can be considered for selected cases.