Morphometric Methods Research Articles

Mining tailings alter insects: revealing fluctuating asymmetry in the caddisfly Smicridea coronata.

The Samarco/Vale/BHP mine tailing dam breach that took place in Minas Gerais, southeastern Brazil, in 2015, deposited high concentrations of metals and metalloids in the Rio Doce basin, severely impacting freshwater and riverine forest ecosystems. To assess developmental instability of caddisflies in response to the environmental impacts of the dam breach, we investigated the fluctuating asymmetry (FA) in the species Smicridea (Rhyacophylax) coronata (Trichoptera: Hydropsychidae). FA was assessed at individual and populational scales using geometric morphometric methods in the cephalic capsule and mandibles of larvae and also on the forewings of adults, both collected under the impacted condition, and under the least disturbed condition. The levels of FA increased in response to stressors on the forewings at the populational scale, and on the mandibles, at individual scale. These morphological variations in the larval and adult stages may lead to detrimental effects and result in high mortality rates as well as lower adult fitness. Trichoptera forewings are revealed as suitable traits for assessing FA, holding potential for applications in biomonitoring programs. Directional asymmetry levels were higher than FA levels for all traits, and this correlation could be explained by a transition from fluctuating to directional asymmetry in the presence of heightened disturbance. Our results validate the relationship between the impacts from the dam breach and increased developmental instability in this species with likely cascade effects on the insect community.

Variety is the spice: The role of morphological variation of Triatoma infestans (Hemiptera, Reduviidae) at a macro-scale

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi (Chagas, 1909). One of the primary vectors of T. cruzi in South America is Triatoma infestans (Klug, 1834). This triatomine species is distributed across a huge latitudinal gradient, inhabiting domiciliary , peridomiciliary , and wild environments. Its wide geographic distribution provides an excellent opportunity to study the relationships between environmental gradients and intraspecific morphological variation. In this study, we investigated variations in wing size and shape in T. infestans across six ecoregions. We aimed to address the following questions: How do wing size and shape vary on a regional scale, does morphological variation follow specific patterns along an environmental or latitudinal gradient, and what environmental factors might contribute to wing variation? Geometric morphometric methods were applied to the wings of 162 females belonging to 21 T. infestans populations, 13 from Argentina (n = 105), 5 from Bolivia (n = 42), and 3 from Paraguay (n = 15). A comparison of wing centroid size across the 21 populations showed significant differences. Canonical Variate Analysis (CVA) revealed significant differences in wing shape between the populations from Argentina, Bolivia, and Paraguay, although there was a considerable overlap, especially among the Argentinian populations. Well-structured populations were observed for the Bolivian and Paraguayan groups. Two analyses were performed to assess the association between wing size and shape, geographic and climatic variables: multiple linear regression analysis (MRA) for size and Partial Least Squares (PLS) regression for shape. The MRA showed a significant general model fit. Six temperature-related variables, one precipitation-related variable, and the latitude showed significant associations with wing size. The PLS analysis revealed a significant correlation between wing shape with latitude, longitude, temperature-related, and rainfall-related variables. Wing size and shape in T. infestans populations varied across geographic distribution. Our findings demonstrate that geographic and climatic variables significantly influence T. infestans wing morphology.

Abstract PS03-07: Morphometric signature identifies ductal carcinoma in situ of the breast with low risk of progression to invasive breast cancer

Abstract Background. Ductal carcinoma in situ (DCIS) is a frequently found precursor of invasive breast cancer (IBC). However, the majority of DCIS will never progress to IBC. As we cannot distinguish yet which DCIS will remain indolent (‘harmless’) from those that might progress in the future to IBC, almost all women with DCIS are intensively treated by surgery, often followed by radiotherapy. This brings an urgent clinical need to learn distinguishing harmless from potentially progressive DCIS to save many women with indolent DCIS the burden of unnecessary overtreatment. Aim. We aimed to investigate if the geometry and spatial configuration of DCIS ducts in Hematoxylin-Eosin (H&E) stained tissue sections are related to the risk of progression of DCIS to ipsilateral IBC (iIBC). Methods. We obtained data from a population-based cohort of women diagnosed with primary DCIS between 1989 and 2004 in the Netherlands, treated with breast conserving surgery (BCS) only and a median follow-up time of 12 years. A nested case-control study (n=689) was designed in which patients diagnosed with iIBC recurrences during follow-up were considered as “cases” (n= 226) and those with no subsequent iIBC as “controls” (n=463). The DCIS and stroma regions were digitally annotated on H&E-stained whole slide images (WSIs) by a pathologist as ground truth for the deep learning neural network of HALO AI module (IndicaLabs). We developed a computational pipeline to automatically detect and measure stroma areas, DCIS ducts, and the nucleus of their cells. We validated the accuracy of DCIS detection in H&Es WSIs from an external study, in which DCIS regions were digitally annotated by an independent pathologist (Translational Breast Cancer Research Consortium, TBCRC). We classified cases and controls according to morphological measurements using logistic ridge regression with double-loop cross-validation, followed by hierarchical clustering. The risk of subsequent iIBC after primary DCIS diagnosis was evaluated by multivariate Cox proportional hazards models. Results. The accuracy of DCIS detection performed by the computational pipeline was compared with pathologist annotations in 20 slides from the TBCRC study. Results showed a satisfactory DCIS overlap area agreement of 0.76 (0.68 – 0.83). We applied the DCIS computational pipeline on the case-control series. We obtained 15 morphological measurements for each DCIS duct, such as duct area, cell density, distance between ducts, average nucleus area, etc. We calculated 8 distribution parameters from each measurement in each WSI, including median and range. After leaving out redundant variables, 55 unique morphometric variables were obtained, representing the heterogeneity of DCIS ducts per WSI. The c lassifier revealed a median area-under the curve (AUC) of 0.66 (0.55-0.77) to predict 5-years free of iIBC, 0.59 (0.50-0.67) to predict 10-years and 0.60 (0.52-0.68) to predict 15-years. The 30 variables with the highest association with outcome were used to build four morphometric signatures. Signature number 1, which is characterized by lesions with small-sized ducts, a lower number of cells and a lower DCIS/stroma area ratio, showed a significant lower risk of developing iIBC compared to the other three signatures in a multivariate Cox regression model including grade, ER, COX-2 and HER2 expression: HR = 0.56 (0.28-0.78 95%CI). Conclusion. We developed a computational pipeline able to detect and measure DCIS ducts in H&E WSIs with high accuracy and reproducibility. DCIS lesions presenting the morphometric signature of small-sized DCIS ducts have a very low chance to progress to invasive breast cancer. After successful validation, our morphometric method will serve as a robust and easy to implement biomarker for de-escalation strategies in DCIS, and as such, could limit unnecessary overtreatment in the near future. Citation Format: Marcelo Sobral-Leite, Simon Castillo, Shiva Vonk, Xenia Melillo, Noomie Lam, Brandi de Bruijn, Yeman Hagos, Joyce Sanders, Mathilde Almekinders, Lindy Visser, Emilie Groen, Carolien Van der Borden, Petra Kristel, Ercan Caner, Leyla Azarang, Yinyin Yuan, Renee Menezes, Esther Lips, Jelle Wesseling, Grand Challenge PRECISION Consortium. Morphometric signature identifies ductal carcinoma in situ of the breast with low risk of progression to invasive breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS03-07.

Human diphyllobothriasis in Argentina: assessing the epidemiological significance from historical records and reports of new cases.

Between 1898 and 1940, eight human cases of diphyllobothriasis were reported in Argentina, always in recently arrived European immigrants. In 1982, the first autochthonous case was detected, and since then, 33 other autochthonous cases have been reported, totaling 42 cases of human diphyllobothriasis in Argentina before the present study. Our aim is to update the information on diphyllobothriasis in Argentina by identifying specimens from new cases using morphometrical and/or molecular methods. We also aim to assess the epidemiological relevance of this food-borne disease in the country. Anamnestic data were obtained from patients or professionals, along with 26 worms identified using morphometrical (21 samples) and molecular techniques (5 samples). All the patients acquired the infection by consuming freshwater salmonids caught in Andean lakes in Northern Patagonia. Morphometrics and DNA markers of worms were compatible with Dibothriocephalus latus. In total, 68 human cases have been detected in Argentina, 60 of which were autochthonous. The human population living North-western Patagonia, whose lakes are inhabited by salmonids, is increasing. Similarly, the number of other definitive hosts for Dibothriocephalus dendriticus (gulls) and for D. latus (dogs) is also increasing. In addition, salmonid fishing and the habit of consuming home-prepared raw fish dishes are becoming widespread. Therefore, it is to be expected that diphyllobothriasis in Argentina will increase further.

Skull asymmetry in various sheep breeds: Directional asymmetry and fluctuating asymmetry.

Sheep (Ovis aries) play an important role in the economy of Turkey and the Balkan Peninsula due to their use in farming. As a domesticated species, sheep's morphometric and morphological diversity is likely determined by selective breeding practices rather than geographic distribution. This study aimed to analyse four different sheep breed skulls and reveal skull asymmetry using geometric morphometric methods. For this purpose, 2D images of 52 sheep skulls from different breeds were analysed from the dorsal view of the skull, using 28 landmarks. In the comparison of sheep skulls from the dorsal view, the first principal components for directional asymmetry (DA) and fluctuating asymmetry (FA) were 32.98% and 39.62% of the total variation, respectively. Sharri and Ivesi (Awassi) sheep breeds had the broadest distribution of skull shapes among the breeds, while Lara e Polisit was the most conservative breed. DA was used as a measure of biomechanical constraints, and FA was used as an indicator of environmental stress. Consistent with DA, both differences in centroid size and shape between breeds were statistically significant. No differences between males and females related to asymmetry were revealed. Ivesi sheep revealed the highest fluctuating asymmetry. Geometric morphometric methods proved to be a useful tool for distinguishing differences in the shape of the skull of different sheep breeds and also can be useful for taxonomic purposes.

Geometric morphometric evaluation of mandibles of four sheep breeds: Bardoka, İvesi, Polish Mountain sheep and Turcana.

The enduring relationship between humans and domestic sheep has evolved over millennia, showcasing diverse uses such as meat, milk, wool, leather and fur, shaped by geographical, historical, cultural and social factors. The sheep breeds discussed include the Ivesi from Southeastern Anatolia, known for its varied animal products; the resilient Turcana breed of Romania; Kosovo's Bardoka, valued for its triple-purpose characteristics; and Poland's Polish Mountain Sheep, uniquely utilized for milk production in cheese making. Sheep, with their enduring relationship with humans and significant economic importance, have attracted scientific interest in morphometric studies of their mandibles, yielding valuable data applicable across various fields including basic anatomy, veterinary clinical anatomy, zooarchaeology and veterinary forensic medicine. Traditional morphometric studies rely on statistical methods to compare length, depth and angular ratios between anatomical formations, often highlighting differences between specific points but not fully revealing shape variations between distinct groups. Geometric morphometric analysis has emerged as a preferred method in recent years, enabling shape analyses using coordinate data from various imaging techniques, facilitating a comprehensive examination of mandibular morphometrics among sheep breeds across different countries. This study involved four sheep breeds from different countries, namely İvesi from Turkey, Bardoka from Kosovo, Polish Mountain Sheep from Poland and Turcana from Romania, with a total of 70 mandibles sourced from various veterinary faculties. Mandibular photographs were meticulously captured, focusing on the right side of mandible pairs and placing landmarks and semi-landmarks along the entire edge, enabling geometric morphometric analysis using tpsUtil, tpsDig2 and MorphoJ software. The analysis included principal component analysis, canonical variate analysis and discriminant function analysis for pairwise comparisons, facilitating a comprehensive examination of mandibular shape variations among the different sheep breeds. Using geometric morphometric methods, this study analysed mandibles from four distinct sheep breeds sourced from different countries, revealing notable variations in regions such as the ramus mandibula, angulus mandibula and incisive areas, attributed to genetic, geographical and dietary influences, highlighting the importance of continued research to better comprehend these shape differences.

Ontogenetic changes in jaw leverage and skull shape in tufted and untufted capuchins.

The ontogeny of feeding is characterized by shifting functional demands concurrent with changes in craniofacial anatomy; relationships between these factors will look different in primates with disparate feeding behaviors during development. This study examines the ontogeny of skull morphology and jaw leverage in tufted (Sapajus) and untufted (Cebus) capuchin monkeys. Unlike Cebus, Sapajus have a mechanically challenging diet and behavioral observations of juvenile Sapajus suggest these foods are exploited early in development. Landmarks were placed on three-dimensional surface models of an ontogenetic series of Sapajus and Cebus skulls (n = 53) and used to generate shape data and jaw-leverage estimates across the tooth row for three jaw-closing muscles (temporalis, masseter, medial pterygoid) as well as a weighted combined estimate. Using geometric morphometric methods, we found that skull shape diverges early and shape is significantly different between Sapajus and Cebus throughout ontogeny. Additionally, jaw leverage varies with age and position on the tooth rowand is greater in Sapajus compared to Cebus when calculated at the permanent dentition. We used two-block partial least squares analyses to identify covariance between skull shape and each of our jaw muscle leverage estimates. Sapajus, but not Cebus, has significant covariance between all leverage estimates at the anterior dentition. Our findings show that Sapajus and Cebus exhibit distinct craniofacial morphologies early in ontogeny and strong covariance between leverage estimates and craniofacial shape in Sapajus. These results are consistent with prior behavioral and comparative work suggesting these differences are a function of selection for exploiting mechanically challenging foods in Sapajus, and further emphasize that these differences appear quite early in ontogeny. This research builds on prior work that has highlighted the importance of understanding ontogeny for interpreting adult morphology.

An Investigation on the Morphometric Characteristics of the White-Spotted Rabbitfish (Siganus canaliculatus Park, 1797) in the Small Semi-Enclosed Bay Based on Truss Morphometric Methods

An Investigation on the Morphometric Characteristics of the White-Spotted Rabbitfish (Siganus canaliculatus Park, 1797) in the Small Semi-Enclosed Bay Based on Truss Morphometric Methods

Sarcomere. The structural unit of the myofibrillar complex of typical cardiomyocytes. Isometric aspects of sarcomere organization

Background. The complexity of understanding the structure and function of cardiomyocytes in the myocardium is a fundamental problem in the field of heart morphology. Sarcomeres are the main structural and functional units of myofibrils. Understanding the organization and dynamics of sarcomeres in cardiomyocytes is crucial for establishing the mechanisms responsible for the process of forming the contractile system of cardiomyocytes. Objective. The main purpose of this study is a review of literary sources that complement and expand the essential findings about the construction of myofibrils and their components when studied by effective methods of microscopic techniques. Materials. Literature review databases, systematic search of primary sources related to the research topic. Methods of visual examination of the components of sarcomeres and elements of their organization. Results. Transmission electron microscopy provides high-resolution imaging of sarcomeres, which is necessary for detailed analysis of their ultrastructure, including visualization of sarcomere components such as Z-discs, M-lines, thick and thin filaments. Morphometric methods are crucial for studying the compaction and orientation of myofibrils in cardiomyocytes. Conclusion. Morphometric methods provide valuable information about the structural remodeling of myofibrils in response to physiological stimuli or pathological conditions. These techniques are needed to improve our understanding of the mechanisms underlying muscle contraction and to develop methods to study cardiac remodeling processes in response to the adaptive response.

Prognostic value of p14ARF expression in diffuse large B cell lymphoma

The p14ARF-Hdm2-p53 signaling pathway targets tumor growth suppression, inhibits clonal proliferation, and maintains genome stability. It is inactivated in most human malignancies. The p14ARF protein is one of the main participants in the cascade. The aim of the study was to determine the prognostic value of the number of p14ARF-expressing tumor cells in biopsies of patients with diffuse large B cell lymphoma (DLBCL). Material and methods. The formalin-fixed paraffin embedded samples of tumor tissue of 104 patients with newly diagnosed DLBCL were included to the study. The relative number of cells expressing p14ARF was determined by immunohistochemical and morphometric methods. Differences in the content of p14ARF-positive tumor cells between groups of patients divided according to clinical and laboratory parameters were determined using the Mann–Whitney U test. Prediction of an unfavorable response to therapy was carried out using binary logistic regression with calculation of the odds ratio and 95 % confidence interval; variables were selected using Wald backward elimination method. The risk of an event occurring was calculated using Cox regression analysis. Results. The content of p14ARF-positive cells is higher in tumor biopsies of patients with high and high-intermediate risk according to the international prognostic index than in patients with low and lowintermediate risk. A relationship between an increase in the number of p14ARF-positive tumor cells, the absence of a complete response to first-line R-CHOP therapy, and an increased risk of death in patients with DLBCL has been established. Conclusions. The studied marker p14ARF can be used as an additional morphological predictor of the unfavorable course of DLBCL.

Sex‐specific consequences of host shift for morphology and fluctuating asymmetry in a seed beetle: an experimental evolution approach

AbstractMorphological plasticity may be induced by altering host plants and commonly it is sex‐specific in phytophagous insects. It is hypothesized that stress in insects caused by a host shift leads to morphological changes and developmental destabilization, which may be identified by fluctuating asymmetry. We performed reciprocal transplant experiments in eight replicated populations of the seed beetle Acanthoscelides obtectus (Say) (Coleoptera: Chrysomelidae, Bruchinae) adapted to common bean (Phaseolus vulgaris L., Fabaceae) as its ancestral host and chickpea (Cicer arietinum L., Fabaceae) as a suboptimal host. Using methods of geometric morphometrics we assessed the effects of the short‐ and long‐term host shift on size and shape variation of beetles of both sexes. We also tested the hypothesis that fluctuating asymmetry is lower when the beetles develop within seeds of the ancestral host. Our results showed that females respond more plastically related to their body size and shape of the abdomen, particularly during a short‐term host shift, suggesting that females have a greater importance in maintaining the population on a new host. The level of fluctuating asymmetry is lowest in males that have evolved for generations on bean indicating that they have the most canalized development, so we suggested that symmetry in A. obtectus is maintained by sexual selection. Even if the beetles are adapted to a suboptimal host over many generations, they stabilize their development after returning to the ancestral host. Our work indicates that host shifts may change morphological aspects of the beetles in a sex‐specific manner and consequently influence their developmental trajectories.

Mass capture fishing in the Marquesas Islands

ABSTRACTMass capture of small fishes with a variety of nets, traps, and weirs was widely practiced and economically important across East Polynesia at western contact. Archaeological research, however, has suggested these technologies were less important during the early settlement period and gained prominence over time. Several explanations have been proposed, including resource depression, changes in marine environments, and/or social and economic reorientations. In the Marquesas Islands, pelagic and offshore fishes were historically well represented in early assemblages relative to most Polynesian islands. Here we report on fishbone assemblages from Nuku Hiva Island that were recovered with fine mesh screens, identified using a wide range of skeletal elements, and analysed with morphometric methods. The Hakaea Beach results demonstrate that mass capture of small fishes was especially important at this locality and sustained over three early, successive occupations. These patterns may reflect the nature of the local fisheries, preferential use of high‐return capture strategies in this reef‐limited setting, and/or purposeful avoidance of ciguatera‐prone fishes and a preference for less vulnerable fishes. Overall, our findings highlight geographic variation in early Marquesan fisheries and provide archaeological evidence that mass capture technologies had an important place in the maritime toolkits of the earliest East Polynesian fishers.

Capturing the cervical spine shape: Angular measurements versus geometric morphometric methods.

The cervical spine manifests a wide shape variation. However, the traditional methods to evaluate the cervical spine curve were never tested against its actual shape. The study's main aim was to determine whether the shape classification of the cervical spine, based on traditional angular measurements, coincides with each other and with the shape captured by the 2D landmark-based geometric morphometric method. The study's second aim was to reveal the associations between the cervical spine shape and the demographic parameters, the head's position, and the spine's sagittal balance. CT scans of the cervical spine of 163 individuals were evaluated to achieve these goals. The shape was assessed by measuring the C2-C7 Cobb angle (CA), the C2-C7 posterior tangent angle (PTA), the curvedness of the arch, and by a 2D landmark-based geometric morphometric method. The position of the head and the sagittal balance of the spine were evaluated by measuring the foramen magnum-C2 Cobb angle (FMCA) and the T1 slope angle (T1SA), respectively. Based on the size of the angle measured, each individual was classified into one of the three cervical 'shape groups' (lordotic, straight, and kyphotic). We found that cervical lordosis was the dominant shape regardless of the measuring methods utilized (46.6%-54.6%), followed by straight neck (28.2%-30.1%), and kyphosis (15.3%-25.2%); however, about a third of the 163 individuals were classified into a different shape group using the CA and PTA methods. The cervical spine angle was sex-independent and age-dependent. The T1SA was significantly correlated with CA and PTA (r = 0.640 and r = 0.585, respectively; p < 0.001). In conclusion, the cervical spine shape evaluation is method-dependent and varies with age.

The male reproductive cycle of the brown basilisk Basiliscus vittatus (Squamata: Corytophanidae) from Tabasco, Southern Mexico.

We used histological and morphometric methods to study the testis and associated glands, including the epididymis, ductus deferens, and renal sexual segment (RSS), of specimens of Basiliscus vittatus sampled from Tabasco, Mexico (17.5926° N, 92.5816° W). Samples were collected throughout 1 year, which included the dry (February to May) and rainy (June to January) seasons. Spermatogenesis in B. vittatus is active throughout the year, but a significant increase in the testicular volume, diameters of seminiferous tubules, height of the germinal epithelium, spermiogenesis, and released spermatozoa occur in the dry season. During the rainy season, all aforementioned parameters decreased except the secretory activity of the epididymis and the RSS, which increased concomitant with an increase of the spermatozoa population within the ductus deferens. These data strongly suggest that B. vittatus reproduce year-round, but males exhibit a peak in spermatogenic activity during the dry season and a peak in insemination and/or copulation at the beginning of the rainy season. We highlight the importance of analyzing not only the testis but also accessory ducts and glands when determining the reproductive cycles of reptiles. The reproductive cycle of B. vittatus is discussed in relation to the environmental conditions of Southern Mexico and is compared to that of other squamates.

Variation in the shape and size of the scale of the Tigris bream (Acanthobrama marmid, Heckel, 1843) from the Tigris River, Türkiye attributed to Seasonality, Age and Sex: A geometric morphometric study

In this study, the Tigris bream Acanthobrama marmid individuals (44 females and 31 males) were captured from the Tigris River. The scale size (as centroid size) and shape were analyzed separately using 2–dimensional geometric morphometric methods. Procrustes ANOVA revealed significant differences in scales size between sexes, while no difference in shape was observed. Groups based on season and age showed significant differences in both size and shape. Female individuals had larger scale sizes than males, with the scales of the Autumn group being larger than those of the Spring and Summer groups. Scale size also increased with age groups. PCA analysis showed variation in the first five components when examined by age, season, and gender. CVA and DFA results indicated significant differences in shape between different age groups and seasonal groups, but no significant differences between sexes were observed.

Cranial variation in species and subspecies of kangaroo rats (Dipodomys, Dipodomyinae, Rodentia) according to geometric morphometrics.

Traditional Dipodomys (sub)species identification uses geography, phenotype, and external/skull measurements. Such measurements are correlated with size and thus redundant. I assessed the value of scaled cranial shape, based on two-dimensional landmarks (analyzed using geometric morphometric methods) in distinguishing Dipodomys taxa, and in summarizing their variation. My dataset includes 601 adult specimens from 20 species (49 operational taxonomic units - OTUs) across 190 localities. Cranial shape was highly useful in classifying Dipodomys taxa without considering geography. The auditory bulla was the most variable region-taxa differed in its hypertrophy, accompanied by different degrees of nearby structure crowding. Cranial shape was weakly allometric, with no significant sexual dimorphism. Weak size dimorphism was detected. (Sub)specific taxonomy is not reflective of shape variation, as the number of subspecies per species is not associated with disparity. Shape had significant phylogenetic signal, but subspecies did not always cluster with conspecifics and species did not always cluster according to phylogenetic relationship/taxonomy. Shape variation was correlated with climate, and species differed in morphological disparity and degree of specialization, which may contribute to divergence in shape variation patterns from phylogeny. D. deserti was the most specialized species, diverging greatly from the genus mean; D. heermanni was the least specialized. This study provides new insights into morphological variation of North American keystone species, several of conservation interest, for example, D. heermanni berkeleyensis, D. h. dixoni, D. nitratoides brevinasus, and D. n. nitratoides.

Analysis of early morphological and functional perivulnar changes in the mucosa of the cecum after suturing with different surgical threads

The correct choice of suture material is the key to successful treatment in abdominal surgery, particularly pediatric surgery. Given this, experimental studies on the effect of sutures made with different surgical threads are one of the most urgent surgery needs. The aim - to conduct a comparative analysis of early morphological and functional changes in the perivulnar region of the mucosa of the rabbit cecum after suturing with polyglactin-910 and polycaprolactone modified with L-arginine. Materials and methods. The study was conducted on 25 rabbits aged 8-10 months in compliance with all bioethical standards and recommendations. The control group consisted of 5 animals; the first experimental group, in which synthetic surgical polyfilamentous absorbable suture polyglactin-910 was used to close the wound defect, and the second experimental group, in which monofilamentous absorbable suture polycaprolactone modified with L-arginine was used to close the wound defect, consisted of 10 rabbits each. All stages of surgical access and sampling of intact cecal wall tissues were performed in the control group. The rabbits of the experimental groups underwent colotomy followed by suturing of the large intestine with appropriate suture material. Each experimental group was divided into two subgroups (5 rabbits in each), in which the condition of the perivulvar region was studied on days 3 and 7, respectively. The animals were not euthanised; during the second operation, tissues of the cecum were taken from the sutured area and the formed scar at the appropriate time. Histological, semi-thin serial sections, electron microscopic, morphometric, and statistical methods were used. Discussion. The average thickness of the cecal mucosa after colotomy increased significantly on days 3-7 when using both surgical threads, but when using polycaprolactone modified with L-arginine, the above indicator was 63.06% and 22.46% lower, respectively, due to a decrease in hyperhydration of the connective tissue component of the mucosa, leukocyte infiltration in the perivulnar area and acceleration of reparative processes. Conclusions. Polycaprolactone modified with L-arginine has a positive effect on the course of morphological and functional processes in the perivulnar region of the rabbit cecum's mucosa. In terms of its characteristics, it is not worse than polyglactin-910. No conflict of interests was declared by the authors.

DEVELOPMENT OF ULTRASTRUCTURAL CHANGES IN DIAPHRAGM MUSCLE FIBERS DURING PARTIAL TRACHEAL STENOSIS IN YOUNG SEXUALLY IMMATURE RATS

Introduction. The study of congenital pathology of the respiratory tract in children is of great importance for theoretical and clinical pediatric otolaryngology. Currently, in the scientific literature there are single works concerning the study of the pathogenesis and clinic of laryngomalacia. First of all, this concerns the effect of acute and chronic hypoxia on the muscles of the respiratory system, in particular, the diaphragm. The aim of thіs work is to reveal the effect of hypoxia on the development of pronounced structural and functional changes in the diaphragm muscles of sexually immature animals when modeling partial tracheal occlusion. Materials and methods. Surgical partial occlusion of the trachea was performed on in sexually immature Wistar rats; we applied electron microscopy, morphometric and statistical research methods.&#x0D; Results. The obtained data demonstrated that the muscle fibers of the diaphragm are characterized by significant structural, functional and metabolic resistance to the development of acute or chronic hypoxia due to limited lung ventilation in rats. The density of muscle fibers did not change in any of the used terms of the experiment (7 and 21 days). On the 7th day of hypoxic exposure, a change in the state of the matrix of mitochondria of muscle fibers was observed, which was accompanied by partial ultrastructural rearrangements of the organization of these organelles. At the same time, no significant changes were observed during histological studies. Electrongrams demonstrated the ultrastructural damages were mainly limited to focal reduction of myofibrils and an increase in the mitochondria's diameter and found as especially pronounced on day 21 (a state of chronic hypoxia) on the muscular component of the respiratory system in rats. These changes are accompanied by the development of dystrophic disorders in the diaphragm myofibrils. On day 21 changes in the transendothelial transport of substance molecules were also detected. This was based on establishing the fact of a significant reduction in the number of pinocytosis vesicles in the cytoplasm of endothelial cells of diaphragm hemocapillaries in animals with partial tracheal occlusion. Disruption of the structural organization of actomyosin complexes was revealed in muscle fibers due to pathological changes in the mitochondria of myofibrils. It should be noted the development of destruction or complete loss of an important ultrastructural component of muscle fibers, Z-lines. These changes were completely absent on the 7th day following the influence of partial tracheal occlusion and the development of acute hypoxia. Moreover, on day 21, partial lysis of a significant amount of myofilaments of muscle fibers was observed. In addition, the development of the process of fiber swelling was detected against the background of which the above-mentioned ultrastructural destruction of the muscular component in the diaphragm was observed. These changes indicate the need for earlier treatment of laryngomalacia in children. The delay in surgical intervention leads to the development of severe or irreversible structural changes not only in the respiratory organs, but also in their muscular system.&#x0D; Conclusion. The muscular elements of the diaphragm have the pronounced and significant resistance to the state of hypoxia under conditions of limited ventilation of the respiratory tract. Ultrastructural and morphometric data, found on the 21st day after the modeling of partial tracheal stenosis, are not only of a compensatory and adaptive in nature, but also signs of pronounced disorders in the muscle fibers of the central part of the diaphragm in test animals.

Relationship between genetic diversity and morpho-functional characteristics of flight-related traits in Triatoma garciabesi (Hemiptera: Reduviidae)

BackgroundTriatoma garciabesi, a potential vector of the parasitic protozoan Trypanosoma cruzi, which is the causative agent of Chagas disease, is common in peridomestic and wild environments and found throughout northwestern and central Argentina, western Paraguay and the Bolivian Chaco. Genetic differentiation of a species across its range can help to understand dispersal patterns and connectivity between habitats. Dispersal by flight is considered to be the main active dispersal strategy used by triatomines. In particular, the morphological structure of the hemelytra is associated with their function. The aim of this study was to understand how genetic diversity is structured, how morphological variation of dispersal-related traits varies with genetic diversity and how the morphological characteristics of dispersal-related traits may explain the current distribution of genetic lineages in this species.MethodsMales from 24 populations of T. garciabesi across its distribution range were examined. The cytochrome c oxidase I gene (coI) was used for genetic diversity analyses. A geometric morphometric method based on landmarks was used for morpho-functional analysis of the hemelytra. Centroid size (CS) and shape of the forewing, and contour of both parts of the forewing, the head and the pronotum were characterised. Length and area of the forewing were measured to estimate the aspect ratio.ResultsThe morphometric and phylogenetic analysis identified two distinct lineages, namely the Eastern and Western lineages, which coincide with different ecological regions. The Eastern lineage is found exclusively in the eastern region of Argentina (Chaco and Formosa provinces), whereas the Western lineage is prevalent in the rest of the geographical range of the species. CS, shape and aspect ratio of the hemelytra differed between lineages. The stiff portion of the forewing was more developed in the Eastern lineage. The shape of both portions of the hemelytra were significantly different between lineages, and the shape of the head and pronotum differed between lineages.ConclusionsThe results provide preliminary insights into the evolution and diversification of T. garciabesi. Variation in the forewing, pronotum and head is congruent with genetic divergence. Consistent with genetic divergence, morphometry variation was clustered according to lineages, with congruent variation in the size and shape of the forewing, pronotum and head.Graphical

Beyond the dominant narratives: Identifying Indigenous and African individuals in Quebec St-Lawrence Valley colonial cemeteries by three-dimensional morphometrical analysis of the temporal bone

In Quebec, written accounts of free or enslaved Indigenous and African individuals during colonial times are few and limited. Three-dimensional geometric morphometric methods applied on 214 temporal bones individuals are used to explore intra-cemetery population variation throughout three centuries (1683–1878), to identify plausible non-European or admixed individuals. First, Principal Component Analysis (PCA) was generated from populations originated from Africa, North-America (Indigenous) and Europe where colonial cemeteries are projected to assess their degree of overlap with the reference groups. Second, Discriminant Function Analysis (DFA) based on typicality probabilities also allowed to assign unknown individuals to the three reference groups. Our results highlighted discrepancy between PCA and DFA. With the PCA, Quebec colonial groups overlap with the Europeans except for three individuals. For the DFA, 64 % (n = 136) were classified as typical to one group and 36 % as atypical (n = 77). Most were European, (82 %; n = 112), followed by those as Indigenous (7 %; n = 10), intermediate between Africans and Indigenous (6 %; n = 8) and Africans (5 %; n = 7). Compared with previous research, one individual from the first Protestant cemeteries of St-Matthew in Quebec could be assessed as plausible African or admixed origin. Two others need further analysis: one from St-Matthew and one from the first Catholic cemetery of Notre-Dame in Montreal. Finally, in response to dominant narratives that focused mainly on Euro-colonists, this research provided for the first time a new snapshot of several colonial population diversity in Quebec, underlining the presence of marginalized groups -especially those of African origin, who are absent from the archaeological reports under study.