Analysis of Movement and Activities of Handball Players Using Deep Neural Networks.

This paper focuses on image and video content analysis of handball scenes and applying deep learning methods for detecting and tracking the players and recognizing their activities. Handball is a team sport of two teams played indoors with the ball with well-defined goals and rules. The game is dynamic, with fourteen players moving quickly throughout the field in different directions, changing positions and roles from defensive to offensive, and performing different techniques and actions. Such dynamic team sports present challenging and demanding scenarios for both the object detector and the tracking algorithms and other computer vision tasks, such as action recognition and localization, with much room for improvement of existing algorithms. The aim of the paper is to explore the computer vision-based solutions for recognizing player actions that can be applied in unconstrained handball scenes with no additional sensors and with modest requirements, allowing a broader adoption of computer vision applications in both professional and amateur settings. This paper presents semi-manual creation of custom handball action dataset based on automatic player detection and tracking, and models for handball action recognition and localization using Inflated 3D Networks (I3D). For the task of player and ball detection, different configurations of You Only Look Once (YOLO) and Mask Region-Based Convolutional Neural Network (Mask R-CNN) models fine-tuned on custom handball datasets are compared to original YOLOv7 model to select the best detector that will be used for tracking-by-detection algorithms. For the player tracking, DeepSORT and Bag of tricks for SORT (BoT SORT) algorithms with Mask R-CNN and YOLO detectors were tested and compared. For the task of action recognition, I3D multi-class model and ensemble of binary I3D models are trained with different input frame lengths and frame selection strategies, and the best solution is proposed for handball action recognition. The obtained action recognition models perform well on the test set with nine handball action classes, with average F1 measures of 0.69 and 0.75 for ensemble and multi-class classifiers, respectively. They can be used to index handball videos to facilitate retrieval automatically. Finally, some open issues, challenges in applying deep learning methods in such a dynamic sports environment, and direction for future development will be discussed.

3D Pose Estimation and Tracking in Handball Actions Using a Monocular Camera.

Player pose estimation is particularly important for sports because it provides more accurate monitoring of athlete movements and performance, recognition of player actions, analysis of techniques, and evaluation of action execution accuracy. All of these tasks are extremely demanding and challenging in sports that involve rapid movements of athletes with inconsistent speed and position changes, at varying distances from the camera with frequent occlusions, especially in team sports when there are more players on the field. A prerequisite for recognizing the player's actions on the video footage and comparing their poses during the execution of an action is the detection of the player's pose in each element of an action or technique. First, a 2D pose of the player is determined in each video frame, and converted into a 3D pose, then using the tracking method all the player poses are grouped into a sequence to construct a series of elements of a particular action. Considering that action recognition and comparison depend significantly on the accuracy of the methods used to estimate and track player pose in real-world conditions, the paper provides an overview and analysis of the methods that can be used for player pose estimation and tracking using a monocular camera, along with evaluation metrics on the example of handball scenarios. We have evaluated the applicability and robustness of 12 selected 2-stage deep learning methods for 3D pose estimation on a public and a custom dataset of handball jump shots for which they have not been trained and where never-before-seen poses may occur. Furthermore, this paper proposes methods for retargeting and smoothing the 3D sequence of poses that have experimentally shown a performance improvement for all tested models. Additionally, we evaluated the applicability and robustness of five state-of-the-art tracking methods on a public and a custom dataset of a handball training recorded with a monocular camera. The paper ends with a discussion apostrophizing the shortcomings of the pose estimation and tracking methods, reflected in the problems of locating key skeletal points and generating poses that do not follow possible human structures, which consequently reduces the overall accuracy of action recognition.

An overview of Human Action Recognition in sports based on Computer Vision.

Human Action Recognition (HAR) is a challenging task used in sports such as volleyball, basketball, soccer, and tennis to detect players and recognize their actions and teams' activities during training, matches, warm-ups, or competitions. HAR aims to detect the person performing the action on an unknown video sequence, determine the action's duration, and identify the action type. The main idea of HAR in sports is to monitor a player's performance, that is, to detect the player, track their movements, recognize the performed action, compare various actions, compare different kinds and skills of acting performances, or make automatic statistical analysis. As an action that can occur in the sports field refers to a set of physical movements performed by a player in order to complete a task using their body or interacting with objects or other persons, actions can be of different complexity. Because of that, a novel systematization of actions based on complexity and level of performance and interactions is proposed. The overview of HAR research focuses on various methods performed on publicly available datasets, including actions of everyday activities. That is just a good starting point; however, HAR is increasingly represented in sports and is becoming more directed towards recognizing similar actions of a particular sports domain. Therefore, this paper presents an overview of HAR applications in sports primarily based on Computer Vision as the main contribution, along with popular publicly available datasets for this purpose.

Active Player Detection in Handball Scenes Based on Activity Measures.

In team sports training scenes, it is common to have many players on the court, each with his own ball performing different actions. Our goal is to detect all players in the handball court and determine the most active player who performs the given handball technique. This is a very challenging task, for which, apart from an accurate object detector, which is able to deal with complex cluttered scenes, additional information is needed to determine the active player. We propose an active player detection method that combines the Yolo object detector, activity measures, and tracking methods to detect and track active players in time. Different ways of computing player activity were considered and three activity measures are proposed based on optical flow, spatiotemporal interest points, and convolutional neural networks. For tracking, we consider the use of the Hungarian assignment algorithm and the more complex Deep SORT tracker that uses additional visual appearance features to assist the assignment process. We have proposed the evaluation measure to evaluate the performance of the proposed active player detection method. The method is successfully tested on a custom handball video dataset that was acquired in the wild and on basketball video sequences. The results are commented on and some of the typical cases and issues are shown.

Bilateral Wilms'Tumor in Trisomy 18 Syndrome: Case Report and Critical Review of the Literature.

We present a patient with trisomy 18 syndrome and bilateral Wilms' tumor representing the second case of the literature. Physicians should remain alert to the possibility of WT in patients with trisomy 18 who may survive beyond infancy. In this event, it may be essential to consider periodic abdominal ultrasound for screening purposes. A critical review of the literature is presented.

Ovarian Teratoma in Routine Biopsy Material During a Five-Year Period.

Teratomas are tumors derived from germ cells, most frequently arising in the gonads. The aim of this study was to determine the number of ovarian teratomas diagnosed in the routine biopsy material at Ljudevit Jurak Clinical Department of Pathology, Sestre milosrdnice University Hospital Center during a 5-year period, as well as their clinical, gross and microscopic characteristics. Teratomas accounted for 48.6% (n=166) of primary ovarian tumors. The patient mean age was 34.74±12.37 years. Difference in the incidence of teratoma between the left and right ovary was not significant; bilateral teratoma was found in 13 patients. Teratomas were detected by ultrasonography in 115 (69.27%) cases and the rest were found during surgery performed for other indications. Most teratomas (n=161; 96.9%) were mature and cystic (dermoid cysts). Mature and solid teratomas were diagnosed in 5 (3.01%), ovarian struma in 2 (1.8%) cases and strumal carcinoid in 1 (1.2%) case. Mature cystic teratomas contained sebaceous material in 123 (76.8%) cases, and a total of 16 teeth were found; 157 (94.5%) teratomas measured <10 cm in largest diameter. Microscopically, mature cystic teratomas most frequently contained ectodermal (skin with appendages, mature glia and nerve ganglia) and mesodermal (fi brous, fat tissue, cartilage and bone) tissues. Frequently found tissues of endodermal origin were respiratory and intestinal epithelia. Small foci of thyroid tissue were found in 20 (12%) teratomas. Chronic granulomatous foreign body reaction in the wall of mature cystic teratomas was found in 11 (6.8%) tumors.

Cystic fibroepithelioma of Pinkus: two new cases and cystic changes in classical fibroepithelioma of Pinkus.

We report two new cases of cystic fibroepithelioma of Pinkus together with immunohistochemical features and analyze the presence of cystic changes in a series of 16 classical fibroepitheliomas of Pinkus. Our findings show that the formation of cystic spaces is most probably caused by ischemic degeneration of stromal fenestrations, rather than by central tumor cell necrosis. This finding is supported by lack of CD34 positive blood vessels in edematous and hyalinized stromal fenestrations undergoing transformation into cystic spaces, as opposed to the uninvolved stromal fenestrations. Therefore, it is probably more accurate to refer to this process as pseudocystic stromal degeneration rather than true cyst formation. Also, two out of 16 classical Pinkus fibroepitheliomas exhibited focal pseudocystic changes in 50% and 10% of the tumor, respectively, demonstrating that this degenerative process can be found, rarely and focally, in classical cases as well.

Effect of chorioamnionitis on mortality, early onset neonatal sepsis and bronchopulmonary dysplasia in preterm neonates with birth weight of < 1,500 grams.

The aim of the study was to investigate the effects of chorioamnionitis on mortality and early onset neonatal sepsis (EONS) and bronchopulmonary dysplasia (BPD) in preterm neonates with birth weight < or = 1,500 g. The study included 395 preterm infants born at the Zagreb Clinical Hospital Center, from January 2001 to December 2005. All the placentas from preterm deliveries were sent for pathological examination. The patients were categorized into two groups: one including patients with chorioamnionitis at placental histology (47%) and the other control group without chorioamnionitis (53%). Neonates were distributed into 3 groups according to gestational age: the first group with 132 (33%) infants born at < or = 28 weeks of gestation, the second with 202 (52%) infant born from 29 to 32 weeks of gestation and the third with 61 (15%) infants born at > or = 33 weeks gestation. Chorioamnionitis was diagnosed significantly more often in the first gestational age group (91/132-69% of infants, chi2 = 51.307, p < 0.05). The outcome was lethal in 67/395 (17%) patients; 55% of them had chorioamnionitis (chi2 = 2.421, p > 0.05). Lethal outcome ensued in 54/132 (41%) infants from the first gestational age group; 30/54 (55%) were born from pregnancies complicated by chorioamnionitis. In comparison with the control group, mortality was significantly higher in the group of premature infants with gestation < or = 28 weeks whose placentas showed chorioamnionitis (chi2 = 7.645, p < 0.01). EONS was probable or confirmed in 100/395 (25%) infants; in 66/100 (66%) infants pregnancy was complicated by chorioamnionitis (chi2 = 22.396, p < 0.01). BPD developed in 25/395 (6%) infants; in 12/25 (48%) infants placentas showed chorioamnionitis (chi2 = 0.022, p > 0.05). In conclusion, premature neonates from pregnancies complicated by chorioamnionitis are more often born at < or = 28 weeks of gestation. Chorioamnionitis in neonates whose gestation is < or = 28 weeks leads to a significantly higher rate of mortality than in neonates with a longer gestation period. A greater incidence of EONS was proven in the group of infants with chorioamnionitis. The difference between the incidence of BPD in preterm infants born from pregnancies complicated by chorioamnionitis and the control group was not significant.

Strumal carcinoid of the ovary: report of two cases.

Primary carcinoid tumors of the ovary account for 5% of ovarian teratomas. They are frequently components of mature cystic teratomas or, less commonly, mucinous cystadenomas. Most tumors are seen in peri- or postmenopausal women with symptoms of enlarging mass, or are incidental findings. Microscopically, there are four major variants of ovarian teratomas of carcinoid type: insular, trabecular, strumal and mucinous. One-third of patients with the insular type of carcinoids have symptoms of the carcinoid syndrome. Strumal carcinoid is an unusual form of ovarian teratoma composed of an intimate admixture of thyroid and carcinoid tissues that vary in their relative proportions. Two patients with ovarian tumors showing typical morphology of primary ovarian strumal carcinoid are described.

The influence of alpha-, beta-, and gamma-melanocyte stimulating hormone on acetaminophen induced liver lesions in male CBA mice.

Research over the past decade has indicated that melanocortin peptides are potent inhibitors of inflammation and a promising source of new anti-inflammatory and cytoprotective therapies. The purpose of the present paper is to compare protective effects of alpha-, beta-, and gamma-melanocyte stimulating hormone on acetaminophen induced liver lesions in male CBA mice. Acetaminophen was applied intragastrically in a dose of 150 mg/kg, and tested substances were applied intraperitoneally 1 hour before acetaminophen. Mice were sacrificed after 24 hours and intensity of liver injury was estimated by measurement of plasma transaminase activity (AST and ALT) and histopathological grading of lesions. It was found that alpha-, beta-, and gamma-MSH decrease intensity of lesions by both criteria in a dose-dependent manner.

Foetal Leydig cells and the neuroendocrine system.

It has been shown that adult human Leydig cells express a number of neuroendocrine markers, and, therefore, could be considered as a part of the neuroendocrine system in the adult. A limited number of studies have dealt with the dynamics of development of human foetal Leydig cells, whereas studies on their neuroendocrine nature are still extremely rare. Therefore, the aim of our study was to investigate the development of human foetal Leydig cells in different weeks of gestation (wg) and to check if these cells express certain markers characteristic of the diffuse neuroendocrine system (DNS). Qualitative, quantitative histological studies and immunohistochemical analyses of human foetal testicular tissue have been performed. According to our data, Leydig cells formed a dynamic population of cells within the interstitum of testes in the period between 15 and 36 wg. The total number of Leydig cells of human foetal testes changed through different stages of gestation by means of 'pulsatile' dynamics (most likely, by following the variable level of gonadotropins). At early stages of development (15-17 wg) immunohistochemical reactions for the expression of neuron specific enolase (NSE) were positive within sex cords and between them, in the interstitum. Pro-spermatogonia in the sex cords were positive, as well as elongated spindle-shaped cells of the interstitum (very likely, precursors of Leydig cells). During the later stages of development (28-36 wg), excluding the pro-spermatogonia, the interstitial Leydig cells were also positive. The results of the immunohistochemical analyses (the expression of NSE) confirmed the hypothesis that human foetal Leydig cells were of neuroendocrine nature.

Wegener's granulomatosis of the breast.

Wegener's granulomatosis is a multisystem disorder characterized by necrotizing granulomatous inflammation and vasculitis of small vessels and can affect any organ system. The most common sites of involvement are upper and lower respiratory tracts, and kidneys. Breast involvement is unusual and very rare. We report a case of breast Wegener's granulomatosis in a 32-year-old woman who presented with pulmonary lesions and palpable masses in the left breast. Mammography showed multiple, sharply delineated nodules without microcalcifications. Ultrasonography revealed multiple hypoechoic solid lesions, some of them with anechoic areas of necrosis. Computed tomography showed multiple nodules. Histopathology of excision biopsy specimens of breast lesions revealed necrotizing granulomatous material consistent with Wegener's granulomatosis. Twenty reports of breast involvement in this rare disease were found in the literature; however, the respective ultrasonographic and computed tomography findings have not hitherto been described.

[The correlation of inflammation and epithelial changes in the Pap smears of cervix uteri]. / Povezanost upale i promjena epitela na uzorku citoloskih razmaza vrata maternice.

UNLABELLED: A modification of The Bethesda System classification of cytologic findings of uterine cervix named Zagreb 1990 has been accepted in Croatia as a unique classification, the use of which has begun after the publication and printing of the new, uniform method of cytologic examination. AIM: The aim of this study was to assess the number and type of cytologic abnormalities of uterine cervix classified according to Zagreb 1990, on routinely examined Pap smears during the 6-year period, and to investigate the connection of these abnormalities with lower genital tract infections. MATERIAL AND METHODS: The retrospective study included Pap smears from the City of Zagreb and from the town of Imotski. A total of 59901 Pap smears (patients aged 17-79) were routinely examined: the cytopathologic diagnosis of CIN I or higher recorded in 3664 (6.12%) of them. The control group consisted of 401 Pap smears of age-matched women referred by the same gynecologists and free from cytologic abnormalities. The most frequently diagnosed epithelial change was CIN 1 (84.57% of all epithelial changes, and 5.17% of total study population), followed by CIN II (10.92%; 0.67%), CIN III (3.11%; 0.19%), and invasive squamous carcinoma (1.31%; 0.08%). Endocervical adenocarcinoma was cytologically diagnosed in only 0.0055% of all Pap smears examined. Inflammation was significantly more common in the group with epithelial dysplasia/carcinoma than in the control group (p < 0.01). Of specific causative agents HPV and Chlamydia trachomatis were significantly more frequently found in the group with epithelial dysplasia/carcinoma than in the control group (p < 0.05 both), however, Gardnerella vaginalis, Trichomonas vaginalis or Candida yielded no significant differences. It is concluded that inflammation very likely contributes to the development of precancerous lesions of the cervix, HPV and Chlamydia showing strongest correlation, at least in a part of our population.

[Use of flow cytometry in the diagnosis of gestational trophoblastic disease]. / Primjena protocne citometrije u dijagnostici gestacijske trofoblasticne bolesti.

INTRODUCTION: Histopathologic analysis of aborted tissue in molar pregnancy is frequently complicated by scarcity of tissue as well as by the fact that ultrasound and biochemistry permit the clinical diagnosis of gestational trophoblastic disease at the very beginning of pregnancy, when all classical morphologic features have not yet developed. Flow cytometry is today a widely used method that can help the pathologist reach a correct diagnosis, having implications for the patient. AIM: To show the role of flow cytometry in addition to classical histopathologic methods in the early diagnosis of gestational trophoblastic disease, i. e. molar pregnancy. PATIENTS AND METHODS: A total of 103 consecutively received placental tissue samples from spontaneous/medically induced abortions were histopathologically examined and submitted to flow cytometry analysis. RESULTS: The patient mean age was 31 (range 19-50) years, and mean gestational age was 10 (range 5-19) weeks. Residual placental tissue with or without degenerative changes was found in 51.5% of the samples; in 8.7% embryonal/fetal tissues were identified as well. The histopathologic diagnosis of partial hydatiform mole was made in 34% and of complete hydatiform mole in 5.8% of cases. The difference in mean age of women according to histopathologic findings or placental ploidy was not significant. Flow cytometry revealed 42.7% of diploid samples, 58.3% of aneuploid samples and 1% of tetraploid samples. Of 53 samples showing normal morphology or degenerative hydropic changes, 60.4% were diploid and 39.6% aneuploid; of 9 samples containing fetal tissues 44.4% were diploid and 55.5% aneuploid (NS). A significant difference (p < 0.01) was found between the placental tissue ploidy with histopathologic diagnosis of residual placental tissue, and with histopathologic diagnosis of partial hydatiform mole (p < 0.001); when fetal tissues were present the difference was not significant CONCLUSION: This study confirmed the partial hydatiform mole to be a common but clinically underdiagnosed condition. Except for the knowledge whether the abortion was caused by cytogenetic factors, flow cytometry helps the pathologist reach an accurate diagnosis and has a place in daily practice.

Congenital juvenile granulosa cell tumor of the testis in a fetus showing full 69,XXY triploidy.

Testicular juvenile granulosa cell tumor (TJGCT) occurs predominantly in infancy and may be associated with sex chromosomal abnormalities. We report a fetus aborted because of cytogenetically confirmed complete XXY triploidy. External genitalia of the fetus were female, with a short and patent vagina. The tumor presented as an abdominal multicystic mass with typical histologic and immunohistological features of JGCT. It was connected with a tubular uterus-like structure. The other gonad was an inguinally localized testis that showed histologically a Sertoli cell adenoma. Malformations typical for triploidy were also present: agenesis of the corpus callosum, stenosis of the pulmonary ostium, and hypoplasia of the lungs and adrenals. To our knowledge this is the first case of TJGCT in a triploid fetus.

Pathological changes in placentas from pregnancies with preeclampsia and eclampsia with emphasis on persistence of endovascular trophoblastic plugs.

AIM: To assess the frequency and types of histopathological changes in placentas from pregnancies complicated by preeclampsia/eclampsia. METHODS: Placentas routinely sent for pathological examination (n=1,689) were studied microscopically and compared to findings of 50 placentas from uncomplicated pregnancies. RESULTS: Out of 1,689 placentas from singleton pregnancies, 279 (16.5%) were from pregnancies complicated by preeclampsia/eclampsia. Seventy five placentas (26.8%) were appropriate for gestational age; other findings included: infarcts of various stage and volume in 63 cases (22.6%), minimal hypoxic damage in 27 cases (9.7%), accelerated maturation in 42 cases (15.1%), chronic villitis in 18 cases (6.5%), mixed findings in 18 cases (6.5%), intervillous thrombosis in 15 cases (5.4%), sub-choral thrombosis in 9 cases (3.2%), immaturity of the villi in 6 cases (2.1%), and findings suggestive of placental insufficiency in 6 cases (2.1%). Normal findings were significantly more frequent in the control group (P<0.001), but no other significant differences between the groups were found. In 4 (1.4%) placentas from pregnancies complicated by preeclampsia/eclampsia (gestational age 32 to 36 weeks), remnants of endovascular trophoblastic plugs in the vessels of the basal decidua were found. CONCLUSION: No significant difference was found between the group of placentas from pregnancies complicated with preeclampsia/eclampsia and the control group with regard to ischemic changes of the placenta. Endovascular trophoblastic plugs in the basal plate vessels from the third trimester placentas may play an additional role in the development of ischemic lesions in the placentas from pregnancies complicated with preeclampsia/eclampsia, but may also simply represent indirect evidence of the abnormal expression of certain adhesion molecules in this disorder.

Vascular anastomoses in dichorionic diamniotic-fused placentas.

A case of fetal twin-to-twin cytomegalovirus infection through a dichorionic diamniotic (DiDi)-fused placenta prompted our search for possible vascular anastomoses in this type of placenta. This case and three additional DiDi-fused placentas were studied with gross (macro) sections and a three-dimensional (3D) stereomicroscopic technique. Two twins were dizygotic (they differed in gender and blood groups) and the other two were probably monozygotic. Macrosections and 3D-image analysis demonstrated side-to-side connections between small subchorionic vessels. These findings demonstrate that vascular anastomoses are present in DiDi-fused placentas.

Malignant potential of dysplastic endocervical epithelium assessed by ploidy status, S-phase fraction and C-myc expression.

The aim of this study was to determine if dysplastic endocervical cells (EC) posses a neoplastic potential as precursor lesions to adenocarcinoma in situ (AIS). The malignant potential was determined by assessing the ploidy status and proliferative activity by flow cytometry and c-myc expression by immunohistochemistry. The studied parameters were assessed separately in morphologically normal, dysplastic and malignant EC. The chi 2 test showed significant association of malignant EC with aneuploidy (p = 0.008) and high proliferative activity (p = 0.042). Since one third of the dysplastic EC are also aneuploid and show high mitotic activity, they probably have malignant potential as well. The dysplastic EC showed a significant association with c-myc oncogene expression (p = 0.028). Our results indicate the existence of pre-malignant glandular lesions, while the immunohistochemical detection of c-myc protooncogene could be helpful in detection of EC with malignant potential, even without any dysplastic morphological changes.