Specific Body Regions Research Articles

Explaining radiation dose exposure : The role of the banana equivalent dose compared to the effective dose in patient communication

Communicating the amount and effects of ionizing radiation to patients prior to an examination using x‑rays is associated with challenges: first, calculating the expected dose prior to the examination and, second, quantifying and illustrating cancer risks. Analogies, such as comparing radiation exposure to accident risks, have limitations and may evoke unease. This study explores and compares two new approaches to discuss radiation exposure from common clinical examinations with patients: effective dose and exposure based on radioactive potassium-40 intake from the ingestion of bananas, the banana equivalent dose (BED). The effective doses of the diagnostic reference levels (DRL) for computed tomography (CT) andX-ray examinations in adults were calculated using mean conversion factors for specific anatomic body regions. For the BED calculation of the diagnostic reference levels, the radiation dose from aconventional banana ingested over 50years per becquerel was calculated. The outcomes were juxtaposed against an equivalent number of bananas and its respective radiation doses. The calculated doses, namely effective dose and BED, of the German DRL can serve as areliable metric to discuss radiation exposure from medical imaging with patients prior to an examination. This is the first study to calculate the effective doses of the current DRL and to compare these with the pseudoscientific unit BED. While the BED serves as an interesting illustration to metaphorize radiation exposure, it is recommended to use the calculated effective dose of the DRL as the basis for educational consultations with patients.

Acupuncture treatment for functional gastrointestinal disorders: Identification of major acupoints using network analysis

BackgroundUsing network analysis, we sought to determine the acupoints most commonly used to treat functional gastrointestinal disorders (FGIDs), particularly functional dyspepsia (FD) and irritable bowel syndrome (IBS). MethodsTo explore the acupoint patterns used for FGID, data on acupoint combinations for FD and IBS were gathered from systematic reviews. Network analysis was used to determine the degree, closeness centrality, betweenness centrality, and eigenvector centrality of each acupoint. The most common acupoint combinations for FD and IBS were examined based on the eigenvector centrality. ResultsNetwork analysis revealed that CV12, ST25, ST36, CV10, and LR3, which had the highest eigenvector centrality values, were the main acupoints for treating FGID. CV12 was the main acupoint for treating FD, while ST25 was the hub acupoint for treating IBS in the abdomen. ST36, LR3, and PC6 were the key peripheral acupoints for FD and IBS. ConclusionsUsing network analysis, we provided data that will aid the selection of both general and specific acupoints for FD and IBS, along with spatial information (i.e., the positions of acupoints on a body map). These findings could be applied in future acupuncture research on therapy for gastrointestinal system dysfunction. They may also help bridge the gap between the traditional meridian theory, which assumes that there is a link between diseases/symptoms and the specific body region being treated, and real-world clinical evidence.

In vivo evaluation of skin of children with LC-OCT: An objective assessment.

Several non-invasive skin imaging methods have been developed in recent years. Line-field confocal optical coherence tomography (LC-OCT) is one of them, leading to the best compromise in terms of resolution and penetration depth. Skin biopsies are an essential technique in paediatric dermatology, but they are a major stressful event for the child and their parents. Current LC-OCT studies have not been dedicated to a paediatric population. If, however, LC-OCT proves to be helpful in children, it may help guide and decrease a certain number of skin biopsies. (1) To evaluate the feasibility of using LC-OCT in paediatric patients, and (2) to assess the maturation of skin structures in children over time with this method. In vivo LC-OCT images were collected on six specific body regions (forehead, forearm, chest, back, dorsum of the hand and palmar surface) and in six age groups (between the ages of 0 and 16 years). In all body areas and age groups assessed, 9 of 10 images were rated as good-to-excellent, the only exception were the images acquired on the palmar surface. LC-OCT allowed visualizing very well the skin structures up to a penetration of 500 μm. We observed that the body regions located on the upper extremities of the body (forearm, dorsum of the hand and palmar surface) showed both a maturation on their structure and differences in thickness with respect to the other regions evaluated. LC-OCT can easily be used for non-invasive imaging of children's skin and allows to document progressive skin changes in the different age groups. It may be a useful asset for imaging and diagnosing superficial skin disorders and as such reducing the number of invasive procedures while increasing the speed of diagnosis in the paediatric population.

Prevalence and impact of work-related musculoskeletal disorders among food delivery riders in Eastern Peninsular Malaysia

Work-related Musculoskeletal Disorders (WMSDs) are currently a matter of concern in the occupational world, where it is the leading cause of disability among workers. Food delivery riders were among the neglected workers even though they were highly exposed to the WMSDs. Thus, this study aims to quantify the magnitude of WMSDs among the riders and the impact on their work. This was a cross-sectional study involving 191 food delivery riders in Eastern Peninsular Malaysia. The Standardized Nordic Musculoskeletal Questionnaire (M-SNMQ), which was self-administered and validated for Malay translation, was used to quantify the prevalence of WMSDS based on various specific body regions. WMSD prevalence over a 12-month period was 74.9%. Upper back pain (UBP) (55.6%) and lower back pain (LBP) (73.3%) were the two most common body regions to experience WMSD symptoms. The least-complained body regions were thighs and feet, with a prevalence of 2.6% and 3.1%, respectively. The affected body regions that caused the highest daily life disturbance were the shoulders and knees, while those with shoulders symptom were more likely to be absent from work. Finally, LBP was the highest body region with at least a moderate pain score. In general, the findings should be a matter of concern among health authorities and others to improve the quality of life among the riders. To lower the prevalence of WMSDs among this understudied group, additional interventional research should be built on the findings of this study.

Correlation between biochemical and clinical hyperandrogenism parameter in polycystic ovary syndrome in relation to age

BackgroundTo assess the correlation between clinical and biochemical hyperandrogenism parameters in polycystic ovary syndrome (PCOS) according to age.MethodsThis prospective study included 256 PCOS patients diagnosed according to the Rotterdam criteria in a university-based hospital. Androgen levels were measured using liquid chromatography-tandem mass spectrometry. Hirsutism, acne, and alopecia were assessed using the modified Ferriman-Gallwey (mF-G) score, Comprehensive Acne Severity Scale (CASS), and the Ludwig scale, respectively. The correlation between biochemical and clinical hyperandrogenism parameters was assessed in younger and older women with PCOS.ResultsThe 256 PCOS patients were classified by age into two groups: age 18–29 years (n = 151) and age 30–40 years (n = 84). In women with PCOS, mF-G was significantly positively correlated with the free androgen index (FAI), dehydroepiandrosterone (DHEA), and DHEA sulfate (DHEA-S). CASS had a significant positive correlation with DHEA. mF-G was positively correlated with FAI in those aged 18–29 years, but the correlations were not significant in those aged 30–40 years. The positive correlation between specific body regions of clinical hyperandrogenism, especially mF-G of chin, lower abdomen, and thighs, and testosterone, as well as with FAI, was highest in those aged 18–29 years. In those aged 30–40 years clinical hyperandrogenism was mainly affected by DHEA, DHEA-S, and dihydrotestosterone.ConclusionThe correlation between biochemical and clinical hyperandrogenism parameters varied with age in our East Asian population. Clinical hyperandrogenism was positively correlated with FAI in younger women with PCOS. The correlation between biochemical and clinical hyperandrogenism was not significant in older women with PCOS.

The immunomodulatory mechanisms for acupuncture practice.

The system physiology approaches that emerge in western countries in recent years echo the holistic view of ancient Traditional Chinese Medicine (TCM) practices that deal with the root, rather than only the symptoms of diseases. Particularly, TCM practices, including acupuncture, emphasize the mobilization of self-healing mechanisms to bring back body homeostasis. Acupuncture has been practiced for over two thousand years to modulate body physiology via stimulation at specific body regions (acupoints). With the development of various research on acupuncture therapy, its regulatory effect on the immune system has been gradually recognized, especially on immunological diseases, including infectious and allergic diseases. In this study, we reviewed the immunomodulatory mechanism of acupuncture and systematically integrates existing research to respectively elucidate the modulatory mechanisms of acupuncture on the innate immune system, adaptive immune system, and well-known neuroanatomical mechanisms, including intact somatosensory-autonomic reflex pathway. With the advances made in recent systems physiology studies, we now have a great opportunity to gain insight into how acupuncture modulates immunity, and subsequently improves its efficacy.

Feasibility of a deep-learning based anatomical region labeling tool for Cone-Beam Computed Tomography scans in radiotherapy.

Currently, there is no robust indicator within the Cone-Beam Computed Tomography (CBCT) DICOM headers as to which anatomical region is present on the scan. This can be a predicament to CBCT-based algorithms trained on specific body regions, such as auto-segmentation and radiomics tools used in the radiotherapy workflow. We propose an anatomical region labeling (ARL) algorithm to classify CBCT scans into four distinct regions: head & neck, thoracic-abdominal, pelvis, and extremity. Algorithm training and testing was performed on 3,802 CBCT scans from 596 patients treated at our radiotherapy center. The ARL model, which consists of a convolutional neural network, makes use of a single CBCT coronal slice to output a probability of occurrence for each of the four classes. ARL was evaluated on the test dataset composed of 1,090 scans and compared to a support vector machine (SVM) model. ARL was also used to label CBCT treatment scans for 22 consecutive days as part of a proof-of-concept implementation. A validation study was performed on the first 100 unique patient scans to evaluate the functionality of the tool in the clinical setting. ARL achieved an overall accuracy of 99.2% on the test dataset, outperforming the SVM (91.5% accuracy). Our validation study has shown strong agreement between the human annotations and ARL predictions, with accuracies of 99.0% for all four regions. The high classification accuracy demonstrated by ARL suggests that it may be employed as a pre-processing step for site-specific, CBCT-based radiotherapy tools.

Wiederherstellungsoperationen (WHO’s): Eine Übersicht - Straffungsoperationen nach massivem Gewichtsverlust

Body contouring procedures are the consequent and final step for patients after massive weight loss. These surgical procedures are mainly indicated for functional reasons resulting from extensive excess skin flaps. The current overview serves as an introduction to body contouring strategies without any claim to comprehensiveness. In the following, we describe the general and specific aspects of the respective body contouring procedures. These are in accordance with the guidelines published by the Association of Scientific Medical Societies in Germany (AWMF). This includes principle anatomical functional features, detailed general and specific aspects of a comprehensive history with the respective physical examination. We also describe the documentation and fundamentals of the application for required assumption of costs for hospital care. The main section deals with the principles of the most frequent lifting operations, such as abdominoplasty, brachioplasty, mastopexy, thigh lift etc. We describe the specific aspects of the specific body regions as well as different surgical techniques, with step-by-step instructions and with pre-, intra- and postoperative pictures.

Temperature independence of haemoglobin-oxygen affinity in smalleye Pacific opah (Lampris incognitus) and swordfish (Xiphias gladius).

Smalleye Pacific opah and swordfish can conserve metabolic heat and maintain specific body regions warmer than ambient water temperature (i.e. regional heterothermy). Consequently, blood O2 uptake at the gills occurs at the environmental temperature at which the individual is found, but O2 offloading will occur at different temperatures in different tissues. While several regionally heterothermic fishes (e.g. billfishes, tunas and sharks) show a reduced temperature effect on haemoglobin (Hb)-O2 affinity, the temperature dependence of Hb-O2 affinity in opah and swordfish is unknown. We hypothesized that the Hb of opah and swordfish would also show a reduced temperature dependence. Opah whole-blood-O2 affinity exhibited a reverse temperature dependence above 50% Hb-O2 saturation (10-20°C, pH7.2-8.0), while the temperature dependence of swordfish blood-O2 affinity (10-25°C) was saturation and pH dependent, becoming temperature independent below 50% Hb-O2 saturation and pH7.4. Experiments on stripped haemolysates showed that adding ATP ([ATP]/[Hb]=30) decreased the temperature sensitivity of Hb-O2 affinity, changing the overall oxygenation enthalpy (ΔH') values of opah (10-20°C) and swordfish (10-25°C) Hbs at pH7.4 from -15 and -42 kJ mol-1 O2, respectively, to +84 and -9 kJ mol-1 O2. Swordfish blood-O2 affinity was high compared with that of other large, pelagic, marine teleosts, which may be the result of unusually low ATP/Hb levels, but might also enable swordfish to forage in the potentially low-oxygenated water of the upper reaches of the oxygen minimum layer. The existence of Hbs with reduced temperature sensitivity in regionally heterothermic fishes may prevent marked changes in Hb-O2 affinity between the cold and warm tissues.

ACL Research Retreat IX Summary Statement: The Pediatric Athlete, March 17-19, 2022; High Point, North Carolina.

ACL Research Retreat IX Summary Statement: The Pediatric Athlete, March 17-19, 2022; High Point, North Carolina.

Anatomic update on the 3-dimensionality of the subdermal septum and its relevance for the pathophysiology of cellulite.

Cellulite is an aesthetic condition affecting the appearance of skin in specific body regions. When reviewing past literature, a 2-D image of a subdermal septum was created most likely due to the applied cross-sectional investigative methodology. Despite practitioners being aware of the 3-D nature of the subdermal architecture, this is not reflected in the present scientific literature. The aim of this anatomic review is to summarize the past literature and to provide an update on the 3-dimensionality of a subdermal septum with a specific focus on the pathophysiology of cellulite. This review is based on the literature search performed in the PubMed database using the keywords: cellulite (n=777), cellulite, AND pathophysiology (n=53). The articles obtained were screened and those focusing on "cellulitis" or other non-cellulite-related topics were additionally excluded resulting in a total of n=38 relevant articles which were evaluated for the purpose of this anatomic review. The skin is comprised of two fat layers (superficial and deep), separated by the superficial fascia. The dynamic 3-D interplay between retinacula cutis, fascia, and fat, with anatomic differences between men and women, highlights a complex anatomic construct with direct implications for the formation and treatment of cellulite. The 3-dimensionality of a subdermal septum provides important clinical clues to understanding the underlying mechanisms and pathogenesis of cellulite. The 3-D approach, in contrast to the past 2-D models, presents a robust foundation for understanding and developing future cellulite therapeutic strategies.

Muscular Ultrasonography in Morphofunctional Assessment of Patients with Oncological Pathology at Risk of Malnutrition.

Background: Muscular ultrasonography is a technique that allows assessing the amount and quality of muscle in a specific body region. The aim of the study was to compare the value of muscle ultrasonography in diagnosis of malnutrition with techniques such as anthropometry, handgrip strength and impedanciometry in patients with oncological pathology. Methods: Cross-sectional study in 43 patients with oncological pathology and high nutritional risk. Classical anthropometry (body mass index (BMI), arm circumference (AC), calf circumference (CC) and estimated appendicular muscle mass index (ASMI)) was performed. Body composition was measured with impedanciometry (BIA), phase angle (PA) and fat-free mass index (FFMI) and muscle ultrasonography of quadriceps rectus femoris (muscle area (MARA) and circumference (MCR) in section transverse). Malnutrition was diagnosed using the GLIM criteria and sarcopenia was assessed using EWGSOP2 criteria. Results: The mean age was 68.26 years (±11.88 years). In total, 23/20 of the patients were men/women. The BMI was 23.51 (4.75) kg/m2. The ASMI was 6.40 (1.86) kg/m2. The MARA was 3.31 cm2 in ultrasonography. In impedanciometry, phase angle was 4.91 (0.75)°; the FFMI was 17.01 kg/m2 (±2.65 kg/m2). A positive correlation was observed between the MARA with anthropometric measurements (AC: r = 0.39, p = 0.009; CC: r = 0.44, p < 0.01; ASMI: r = 0.47, p < 0.001); and with BIA (FFMI: r = 0.48, p < 0.01 and PA: r = 0.45, p < 0.001). Differences were observed when comparing the MARA based on the diagnosis of sarcopenia (Sarcopenia: 2.47 cm2 (±0.54 cm2); no sarcopenia: 3.65 cm2 (±1.34 cm2); p = 0.02). Conclusions: Muscle ultrasonography correlates with body composition measurement techniques such as BIA and anthropometry in patients with cancer.

Workplace-related musculoskeletal injury trends in the United States from 1992 to 2018

IntroductionThe purpose of our study is to assess workplace-related musculoskeletal (wrMSK) injury trends by utilizing Bureau of Labor Statistics (BLS) data. We hypothesize that trunk injuries are the most commonly reported, injuries occur most frequently in the manufacturing sector, and that injury type occurrence differs according to body region affected. MethodsThis study assessed wrMSK injury data provided by the BLS from 1992 to 2018. The three main body regions analyzed were lower extremity (LE), upper extremity (UE), and trunk. Injury data was also assessed by industrial sector (Agriculture, Manufacturing, Healthcare, and Construction) and injury type (fractures, multiple injuries, sprains/strains/tears, tendonitis, cuts/lacerations, pain/soreness, and bruises). Negative binomial regression and pairwise comparisons with a Benjamini-Hochberg adjustment were utilized to compare calculated incidence rate ratios for wrMSK injuries. Exponentiated beta estimates were used to calculate the estimated annual percent changes of wrMSK injuries within each industrial sector. ResultsOccurrence of wrMSK injuries from 1992 to 2018 was significantly lower for LE when compared to both upper extremity and trunk (p < 0.001). Manufacturing is shown to be the industry with the most wrMSK injuries in each of UE, LE, and trunk. wrMSK injuries were shown to decrease in each industrial sector over the timespan assessed, with the greatest percent change occurring in the manufacturing sector. Lacerations and tendonitis were the most common diagnosis types in UE, while pain/soreness and strains/sprains/tears were most common in trunk and bruises were most common in LE. DiscussionFrom 1992 to 2018, trunk injuries were the most frequently occurring wrMSK injury, but not to a significantly higher degree than upper extremity injuries. wrMSK injury types that may require orthopedic surgical care affect specific body regions to different degrees, with cuts/lacerations and tendonitis most commonly affecting the upper extremity. Thus, it appears that wrMSK injuries in the upper extremity are of particular importance from an orthopedic care perspective.

Adult occupant injury risk in rear impact and frontal impact: Effect of impact conditions and occupant-related factors

Objectives The objectives of this study were to compare the adult occupant injury risk on specific body regions in frontal and rear impact and to investigate the effect of those crash conditions and occupant-related factors on the injury risk. Method Data from the NASS-CDS and Crash Investigation Sampling System were studied for crashes during 2000 to 2019 involving model year 2000 to 2020 motor vehicles, including frontal collisions and rear-end collisions. The injury risk by specific body regions were compared by descriptive statistics, and logistic regression models were developed to examine the effects of various factors on injury risk by specific body regions, controlling for crash type (frontal impact and rear impact), vehicle impact speed, vehicle impact location, vehicle model year, and occupant gender, age, belt use, and seating position. Results After controlling for the confounding factors, the occupants in frontal impact had higher overall injury risk than in rear impact (at Maximum Abbreviated Injury Scale [MAIS] 3+; odds ratio [OR] = 6.23; 95% confidence interval [CI] [6.06–6.40]), except for lower neck/spine injury risk at MAIS 1+ (OR = 0.47; 95% CI [0.46–0.47]). The impact speed (at MAIS 3+; OR = 1.10; 95% CI [1.10–1.10]) and aging (at MAIS 3+; OR = 1.05; 95% CI [1.05–1.05]) increase overall injury risk, and the unbelted occupants had higher overall injury risk than belted occupants not only in frontal impact (at MAIS 3+; OR = 4.04; 95% CI [3.98–4.10]), but also in rear impact (at MAIS 3+; OR = 28.4; 95% CI [26.4–30.5]). Females had higher overall injury risk than males in frontal impact (at MAIS 3+; OR = 2.01; 95% CI [1.99–2.04]) but not in rear impact (at MAIS 3+; OR = 0.77; 95% CI [0.73–0.81]). Conclusions Occupants in rear impact had lower injury risk than in frontal impact at MAIS 1+ to MAIS 3+, except for neck/spine at MAIS 1+. The belt restraint was effective not only in frontal impact but also in rear impact. This study provided injury risk references for current vehicles that may provide insight to the potential injury risk of rear-facing occupants in future vehicle configurations.

A Statistical Model to Determine Biomechanical Limits for Physically Safe Interactions With Collaborative Robots

Collaborative robots (cobots) provide a wide range of opportunities to improve the ergonomics and efficiency of manual work stations. ISO/TS 15066 defines power and force limiting (PFL) as one of four safeguarding modes for these robots. PFL specifies biomechanical limits for hazardous impacts and pinching contacts that a cobot must not exceed to protect humans from serious injuries. Most of the limits in ISO/TS 15066 are preliminary, since they are based on unverified data from a literature survey. This article presents a human-subject study that provides new and experimentally verified limits for biomechanically safe interactions between humans and cobots. The new limits are specifically tailored to impact and pinching transferred through blunt and semi-sharp surfaces as they can occur in the event of human error or technical failures. Altogether 112 subjects participated in the study and were subjected to tests with emulated impact and pinching loads at 28 different body locations. During the experiments, the contact force was gradually increased until the load evoked a slightly painful feeling on the subject’s body location under test. The results confirm that the pain thresholds of males and females are different in specific body regions. Therefore, when defining biomechanical limits, the gender difference must be taken into account. A regression model was utilized to incorporate the gender effect as a covariate into a conventional statistical distribution model that can be used to calculate individual limits, precisely fitted to a specific percentile of a mixed group of male and female workers which interacting with cobots.

A high-throughput method to deliver targeted optogenetic stimulation to moving C. elegans populations.

We present a high-throughput optogenetic illumination system capable of simultaneous closed-loop light delivery to specified targets in populations of moving Caenorhabditis elegans. The instrument addresses three technical challenges: It delivers targeted illumination to specified regions of the animal’s body such as its head or tail; it automatically delivers stimuli triggered upon the animal’s behavior; and it achieves high throughput by targeting many animals simultaneously. The instrument was used to optogenetically probe the animal’s behavioral response to competing mechanosensory stimuli in the the anterior and posterior gentle touch receptor neurons. Responses to more than 43,418 stimulus events from a range of anterior–posterior intensity combinations were measured. The animal’s probability of sprinting forward in response to a mechanosensory stimulus depended on both the anterior and posterior stimulation intensity, while the probability of reversing depended primarily on the anterior stimulation intensity. We also probed the animal’s response to mechanosensory stimulation during the onset of turning, a relatively rare behavioral event, by delivering stimuli automatically when the animal began to turn. Using this closed-loop approach, over 9,700 stimulus events were delivered during turning onset at a rate of 9.2 events per worm hour, a greater than 25-fold increase in throughput compared to previous investigations. These measurements validate with greater statistical power previous findings that turning acts to gate mechanosensory evoked reversals. Compared to previous approaches, the current system offers targeted optogenetic stimulation to specific body regions or behaviors with many fold increases in throughput to better constrain quantitative models of sensorimotor processing.

Risk factors for hypertension and diabetes comorbidity in a Korean population: A cross-sectional study.

BackgroundHypertension and diabetes are risk factors for severe cardiovascular disease and are prevalent comorbidities. No studies have examined the associations of various risk factors related to anthropometry, bone mineral density and body composition of specific body regions with hypertension and diabetes comorbidity (HDC). This study explored the association between HDC and various risk factors related to specific body regions.MethodA total of 7,978 subjects (3,451 men and 4,527 women) aged ≥ 50 years were included in the analysis. A binary logistic regression analysis based on complex sample data analysis was conducted to examine associations between the normal and diabetes groups, between the normal and hypertension groups, and between the normal and HDC groups.ResultsAmong Korean adults aged ≥ 50 years, 11.27% of men and 10.05% of women had both diabetes and hypertension. The HDC prevalence was higher in men than in women. In men, waist-to-height ratio (WHtR, adjusted OR = 1.63 [1.22–2.18], adjusted p<0.001) exhibited a more significant association with HDC than other indices, left leg fat mass (adjusted OR = 0.61 [0.45–0.81], adjusted p = 0.0009) and right leg fat mass (adjusted OR = 0.60 [0.45–0.81], adjusted p = 0.0007) displayed strong negative associations with diabetes, and left leg lean mass (adjusted OR = 0.77 [0.67–0.89], adjusted p = 0.0002) and trunk fat mass (adjusted OR = 1.28 [1.07–1.52], adjusted p = 0.0062) were significantly associated with hypertension. In women, left leg fat mass (adjusted OR = 0.29 [0.22–0.39], adjusted p<0.0001) and right leg fat mass (adjusted OR = 0.32 [0.23–0.45], adjusted p<0.0001) exhibited strong negative associations with HDC, waist circumference (WC) (adjusted OR = 2.15 [1.40–3.30], adjusted p = 0.0005) showed a stronger association with diabetes than did other indices, and WC (adjusted OR = 1.39 [1.11–1.74], adjusted p = 0.0040) and WHtR (adjusted OR = 1.39 [1.09–1.76], adjusted p = 0.0075) were significantly associated with hypertension.DiscussionHDC was more strongly associated with fat and lean mass than diabetes and hypertension. The association between HDC and body fat variables was more robust in women than in men.

Turtling the Salamander: Tail Movements Mitigate Need for Kinematic Limb Changes during Walking in Tiger Salamanders (Ambystoma tigrinum) with Restricted Lateral Movement.

SynopsisLateral undulation and trunk flexibility offer performance benefits to maneuverability, stability, and stride length (via speed and distance traveled). These benefits make them key characteristics of the locomotion of tetrapods with sprawling posture, with the exception of turtles. Despite their bony carapace preventing lateral undulations, turtles are able to improve their locomotor performance by increasing stride length via greater limb protraction. The goal of this study was to quantify the effect of reduced lateral flexibility in a generalized sprawling tetrapod, the tiger salamander (Ambystoma tigrinum). We had two potential predictions: (1) either salamanders completely compensate by changing their limb kinematics, or (2) their performance (i.e., speed) will suffer due to the reduced lateral flexibility. This reduction was performed by artificially limiting trunk flexibility by attaching a 2-piece shell around the body between the pectoral and pelvic girdles. Adult tiger salamanders (n = 3; SVL = 9–14.5 cm) walked on a 1-m trackway under three different conditions: unrestricted, flexible shell (Tygon tubing), and rigid shell (PVC tubing). Trials were filmed in a single, dorsal view, and kinematics of entire midline and specific body regions (head, trunk, tail), as well as the fore and hind limbs, were calculated. Tygon individuals had significantly higher curvature than both PVC and unrestricted individuals for the body, but this trend was primarily driven by changes in tail movements. PVC individuals had significantly lower curvature in the trunk region compared with unrestricted individuals or Tygon; however, there was no difference between unrestricted and Tygon individuals suggesting the shells performed as expected. PVC and Tygon individuals had significantly higher curvature in the tails compared with unrestricted individuals. There were no significant differences for any limb kinematic variables among treatments including average, minimum, and maximum angles. Thus, salamanders respond to decreased lateral movement in their trunk by increasing movements in their tail, without changes in limb kinematics. These results suggest that tail undulations may be a more critical component to sprawling-postured tetrapod locomotion than previously recognized.

Changes in Body Surface Temperature Associated with High-Speed Treadmill Exercise in Beagle Dogs Measured by Infrared Thermography.

Simple SummaryHeat exchange between the body surface and the external environment plays an important role in the regulation of body temperature in animals. Previous studies on the effect of exercise on the distribution of body surface temperature in dogs have been conducted on a variety of breeds and did not employ specific defined regions of interest. The aim of our research was to assess the influence of high-speed treadmill exercise on body surface temperature using infrared thermography in selected body regions of healthy Beagle dogs, taking into account gait and recovery time. The study was based exclusively on the Beagle breed, which presents short, uniform, and straight hair, conducting heat more readily from the skin. Statistical analysis indicated the highest temperature at the upper forearm and thigh, and the lowest on the croup, back, and neck. The peak surface temperature values in all examined areas were observed after the canter and the post-gallop walk, and the lowest were observed 2 h after exercise. Our study confirms that the body surface temperature of Beagle dogs is influenced by high-speed physical exercise on a treadmill as a result of muscle activity and changes in blood flow. The proximal forelimb and hindlimb were the most influenced by exercise.Evaluation of body surface temperature change in response to exercise is important for monitoring physiological status. The aim of the study was to assess the influence of high-speed treadmill exercise on body surface temperature using infrared thermography (IRT) in selected body regions of healthy Beagle dogs, taking into account gait and recovery time. Thermographic images of the dogs were taken before exercise (BE), after walk (AW), after trot (AT), after canter (AC), just after second walk (JAE), 5 min after exercise (5 AE), 15 min after exercise (15 AE), 30 min after exercise (30 AE), 45 min after exercise (45 AE), and 120 min after exercise (120 AE). Body surface temperature was measured at the neck, shoulder, upper forearm, back, chest, croup, and thigh. Statistical analysis indicated the highest temperature at the upper forearm, shoulder, and thigh, and the lowest on the croup, back, and neck. The peak values of surface temperature in all ROIs were at AC and JAE and the lowest at 120 AE. The study demonstrated that body surface temperature was influenced by high-speed physical exercise on a treadmill and IRT was a viable imaging modality that provided temperature data from specific body regions. The proximal forelimb and hindlimb were the most influenced by exercise.

Sexually dimorphic skin glands in the invasive species Lithobates catesbeianus (Anura: Ranidae)

Abstract Males of most amphibian species possess specialized cutaneous glands, known as sexually dimorphic skin glands (SDSGs). SDSGs are usually clustered in specific body regions and are externally visible, but in some cases, external differences between males and females can be slight or absent, and the occurrence of SDSGs can only be disclosed by histological studies. Chemical signals produced by SDSGs markedly affect amphibian behaviour and reproduction, and therefore their occurrence, features, and location in the body could provide information on potential mechanisms of intraspecific communication in a particular species. In the present study, we perform light microscope (both histological and histochemical), and scanning electron microscope studies of skin samples from male and female adult specimens of the invasive bullfrog Lithobates catesbeianus, covering several body regions that could hold SDSGs. Most skin areas analysed showed only ordinary granular and mucous glands despite remarkable sexual dimorphism that could be externally observed. By contrast, the male nuptial pads contained exclusively SDSGs that were hypertrophied specialized mucous glands (SMGs), closely resembling breeding glands described in other anurans. Our histochemical study revealed that these SMGs contain heterogeneous populations of secretory cells, possibly involved in pheromone production. We discuss these characteristics of the SDSGs found in L. catesbeianus, as well as the surface specialization of the nuptial pads (achieved by scanning electron microscopy) in the light of their potential role in the chemical communication in this invasive species.