Anterior Region Of Body Research Articles

Paravertebral crystal deposition disease: a retrospective study of clinical presentation, prevalence, and CT imaging findings.

Paravertebral crystal deposition disease, characterized by the deposition of crystals around the vertebral bodies leading to acute inflammation and pain, is a condition that remains largely unrecognized. This study aims to elucidate the prevalence, clinical features, and CT findings associated with this disease. We retrospectively analyzed 14,839 consecutive patients who underwent chest and/or abdominal CT (September 2017 to September 2024) owing to chest, abdominal, or back pain. Cases demonstrating paravertebral calcification with a surrounding soft tissue density of ≥ 5mm were identified and further evaluated. Twenty-four cases of paravertebral crystal deposition disease were identified, with a prevalence of 0.16% (95% CI: 0.10, 0.24). The mean age was 46.2years, with a female predominance (n = 15, 63%). Back pain was the most common presenting symptom (n = 15, 63%). Calcifications were primarily located at the lower thoracic and upper lumbar spine (Th6/7-L1/2) in 18 cases (75%) and in the anterior median to anterior right region of the vertebral body in 21 cases (86%). Mean of maximum CT values of the crystal deposition was approximately 800 HU; in follow-up cases, the depositions either resolved or exhibited morphological changes. This study adds to the current knowledge base by identifying a 0.16% prevalence of paravertebral crystal deposition disease in patients with torso pain-often overlooked in clinical practice, primarily affecting middle-aged women. CT imaging shows calcifications mainly in the lower thoracic and upper lumbar spine. Considering this self-limiting disease in differential diagnoses can improve diagnostic accuracy and patient management.

The organization of the muscle system of the causative agent of dicrocoeliosis, Dicrocoelium dendriticum

AbstractThe musculature of parasitic flatworms plays a central role in locomotory movement, attachment to the host, and in the function of the digestive, reproductive, and excretory systems. We examine for the first time the muscle system of the flatworm Dicrocoelium dendriticum, a causative agent of the parasitic disease dicrocoeliosis, by use of fluorescently labeled phalloidin and confocal laser scanning microscopy. Somatic musculature of D. dendriticum consists of the circular, longitudinal, and diagonal muscles. The distribution of the muscle fibers in the body wall differed among the anterior, middle, and posterior body regions of the worm. The musculature of the attachment organs, the oral and ventral suckers, includes several types of muscles: the external equatorial and meridional muscles, internal circular and semicircular muscles, and radial muscles. Inside of the ventral sucker the diagonally located muscles were revealed and the supplementary u‐shaped muscles were found adjoined to the base of the sucker from outside. The musculature of the internal organs composed of the excretory, reproductive, and digestive systems were characterized. Our results increase our knowledge of the morphology of trematodes and the arrangement of their muscle system.

Neurosensory Recovery Following Skeletonization of Mental Nerve During Open Reduction & Internal Fixation for Mandibular Fractures

Background: Intraoral open reduction and internal fixation (ORIF) procedures used to treat mandibular fractures can result in neurosensory abnormalities due to soft tissue and nerve manipulation. While treating fractures located in the parasymphysis and anterior body regions, where the inferior alveolar and mental nerves are located, there is limited access which can impede correct reduction and hinder the use of optimal fixation. To counter these problems, better access can be gained through skeletonization of the mental nerve, which is known to result in neurosensory disturbances. However, the extent of neurosensory deficits that may result from these procedures and the degree of their recovery remain unknown in current literature. Objective: The primary purpose of our study was to evaluate and correlate the objective and subjective neurosensory recovery of the mental nerve following skeletonization during Open Reduction and Internal Fixation of mandibular fractures. Study Design: This was a prospective observational study. Settings: The adult subjects having mandibular fractures treated at Jinnah Hospital, Lahore Pakistan, a level III tertiary care hospital. Duration: The study duration was from July 1, 2022 and December 31, 2022. Methods: Demographic details were taken and preoperative objective and subjective neurosensory assessment was performed. Following surgery, postoperative objective and subjective neurosensory assessment was performed on post op day 1, after 1 and 6 weeks. Collected data was analysed with significance level of <0.05. Results: Twenty four subjects who completed regular follow-up visits for 6 weeks were included in this study. All subjects had objective or subjective neurosensory deficit preoperatively. Following surgery, all the subjects had FSR grade S0 and subjective loss of sensation at immediate postoperative assessment after surgery. 87.5% of the subjects had complete objective and subjective neurosensory recovery at the end of 6 weeks. There was a significant negative correlation between objective and subjective neurosensory recovery during the initial stages of the study, which became non-significant by the end of 6 weeks. Conclusion: Following mental nerve skeletonization during ORIF of subjects with mandibular fractures having some degree of preoperative paraesthesia, a majority of subjects achieved complete neurosensory recovery 6 weeks postoperatively. Therefore, it is expected for a skeletonized mental nerve to return to normal function within 2 months after ORIF for mandibular fractures.

Lateral Bone Augmentation Using a Three-Dimensional-Printed Polymeric Chamber to Compare Biomaterials.

The aim of this study was to test the suitability of calcium phosphate cement mixed with poly(lactic-co-glycolic acid) (CPC-PLGA) microparticles into a ring-shaped polymeric space-maintaining device as bone graft material for lateral bone augmentation. Therefore, the bone chambers were installed on the lateral portion of the anterior region of the mandibular body of mini-pigs. Chambers were filled with either CPC-PLGA or BioOss® particles for comparison and left for 4 and 12 weeks. Histology and histomorphometry were used to obtain temporal insight in material degradation and bone formation. Results indicated that between 4 and 12 weeks of implantation, a significant degradation of the CPC-PLGA (from 75.1% to 23.1%), as well as BioOss material, occurred (from 40.6% to 14.4%). Degradation of both materials was associated with the presence of macrophage-like and osteoclast-like cells. Furthermore, a significant increase in bone formation occurred between 4 and 12 weeks for the CPC-PLGA (from 0.1% to 7.2%), as well as BioOss material (from 8.3% to 23.3%). Statistical analysis showed that bone formation had progressed significantly better using BioOss compared to CPC-PLGA (p < 0.05). In conclusion, this mini-pig study showed that CPC-PLGA does not stimulate lateral bone augmentation using a bone chamber device. Both treatments failed to achieve "clinically" meaningful alveolar ridge augmentation.

New species of Farlowella (Siluriformes: Loricariidae) from the rio Tapajós basin, Pará, Brazil

Abstract A new species of stick-catfish Farlowella is described from streams of the lower rio Tapajós drainage, in Pará State, northern Brazil. The new species is distinguished from all congeners by a naked gular region (vs. gular region with plates) and from most congeners by the presence of five lateral series of plate rows on anterior region of body (vs. four). The new species shows variation in the series of abdominal plates and a discussion on the variation of abdominal plates within Farlowella is made and comments on synapomorphic characters in Farlowellini.

Texas beetle larvae (Brachypsectridae) – the last 100 million years reviewed

Larvae of Brachypsectridae (Texas beetles) have often been considered rare. However, they are known from North America, Asia and Australia in the extant fauna, and from Miocene, Eocene and Cretaceous ambers. We review the overall record of extant and fossil larvae of Brachypsectridae represented in the literature. Furthermore, we present three new specimens, which were all documented via light microscopy. Two of the specimens are from Baltic amber, and the third one is from the Cretaceous amber of Myanmar; the latter was additionally documented via synchrotron radiation micro-computed tomography. The number of known extant specimens, more than 20, is unusually high compared to other small groups of beetles and with respect to the low number of eight formally described species. The number of fossil specimens from the Miocene, Eocene and Cretaceous is low, two to three specimens per time slice. This makes a comparison of morphological diversity difficult. Still such an analysis of overall body shape as well as of the anterior body region revealed no significant quantitatively recognisable changes over time. However, some qualitative changes in the morphology of the antenna and lateral processes from the Cretaceous to younger faunas could be identified.

Myogenesis of Siboglinum fiordicum sheds light on body regionalisation in beard worms (Siboglinidae, Annelida)

BackgroundMany annelids, including well-studied species such as Platynereis, show similar structured segments along their body axis (homonomous segmentation). However, numerous annelid species diverge from this pattern and exhibit specialised segments or body regions (heteronomous segmentation). Recent phylogenomic studies and paleontological findings suggest that a heteronomous body architecture may represent an ancestral condition in Annelida. To better understand the segmentation within heteronomous species we describe the myogenesis and mesodermal delineation of segments in Siboglinum fiordicum during development.ResultsEmploying confocal and transmission electron microscopy we show that the somatic longitudinal musculature consists of four separate strands, among which ventrolateral one is the most prominent and is proposed to drive the search movements of the head of the late metatrochophore. The somatic circular musculature lies inside the longitudinal musculature and is predominantly developed at the anterior end of the competent larva to support the burrowing behaviour. Our application of transmission electron microscopy allows us to describe the developmental order of the non-muscular septa. The first septum to form is supported by thick bundles of longitudinal muscles and separates the body into an anterior and a posterior region. The second group of septa to develop further divides the posterior body region (opisthosoma) and is supported by developing circular muscles. At the late larval stage, a septum reinforced by circular muscles divides the anterior body region into a forepart and a trunk segment. The remaining septa and their circular muscles form one by one at the very posterior end of the opisthosoma.ConclusionsThe heteronomous Siboglinum lacks the strict anterior to posterior sequence of segment formation as it is found in the most studied annelid species. Instead, the first septum divides the body into two body regions before segments are laid down in first the posterior opisthosoma and then in the anterior body, respectively. Similar patterns of segment formation are described for the heteronomous chaetopterid Chaetopterus variopedatus and serpulid Hydroides elegans and may represent an adaptation of these annelids to the settlement and transition to the sedentarian-tubiculous mode of life.

Evidence for a gradient within the medial temporal lobes for flexible retrieval under hierarchical task rules.

A fundamental question in memory research is how the hippocampus processes contextual cues to retrieve distinct mnemonic associations. Prior research has emphasized the importance of hippocampal-prefrontal interactions for context-dependent memory. Our fMRI study examined the human medial temporal lobes (MTL) and their prefrontal interactions when retrieving memories associated with hierarchically organized task contexts. Participants learned virtual object-location associations governed by subordinate and superordinate task rules, which could be independently cued to change. On each fMRI trial, participants retrieved the correct object for convergent rule and location contextual information. Results demonstrated that hippocampal activity and hippocampal-prefrontal functional interconnectivity distinguished retrieval under different levels of hierarchically organized task rules. In explicit contrast to the hippocampal tail, anterior (body and head) regions were recruited specifically for superordinate changes in the contextual hierarchy. The hippocampal body also differed in its functional connectivity with the prefrontal cortex for superordinate versus subordinate changes. Our findings demonstrate a gradient in MTL for associative retrieval under changing task rules, and advance understanding of hippocampal-prefrontal interactions that support flexible contextual memory.

Analysis of HOX gene expression and the effects of HOXA9 overexpression in fibroblasts derived from keloid lesions and normal skin.

Keloids are fibroproliferative lesions resulting from an abnormal wound healing process due to pathological mechanisms that remain incompletely understood. Keloids tend to occur more frequently in anterior versus posterior body regions (e.g., ears, face, upper torso); this has been attributed to higher skin tension in those areas, although this has not yet been conclusively proven. Previous studies reported reduced expression of multiple homeobox (HOX) genes in keloid versus normal fibroblasts, suggesting a role for HOX genes in keloid pathology. However, HOX genes are differentially expressed along the anterior-posterior axis. Hypothetically, differential HOX expression may be due to differences in body sites, as matched donor sites are often unavailable for keloids and normal skin. To better understand the basis for differential HOX gene expression in cells from keloids compared with normal skin, we compared HOXA7, HOXA9, HOXC8 and HOXC11 expression in keloid and normal skin-derived fibroblasts from various body sites. When keloid (N= 20) and normal (N= 12) fibroblast cell strains were evaluated, expression of HOXA7, HOXA9 and HOXC8 was significantly lower in keloid versus normal fibroblasts. However, HOX gene expression was lower in fibroblasts from more anterior versus posterior body sites. When keloid and normal cells from similar body sites were compared, differential HOX expression was not observed. To investigate the phenotypic relevance of HOX expression, HOXA9 was overexpressed in keloid and normal fibroblasts. HOXA9 overexpression did not affect proliferation but significantly reduced fibroblast migration and altered gene expression. The results suggest that differential HOX expression may be due to differences in positional identity between keloid and normal fibroblasts. However, HOX genes can potentially regulate fibroblast phenotype, suggesting that differential HOX gene expression may play a role in keloid development in anterior body sites.

An interesting rare tylenchid species, Antarctenchus urmiensis n. sp. (Tylenchomorpha; Psilenchidae) from Urmia Lake islands, northwest Iran, with a discussion on the taxonomy of related genera

Abstract A population of an amphidelphic tylenchid nematode was recovered from Urmia Lake islands in association with native shrubs of the region. It had a Tylenchidae-type cloacal bursa in male and looked morphologically similar to the genera under the family Psilenchidae sensu Siddiqi, representing a new species, described and illustrated in present study as Antarctenchus urmiensis n. sp. It is characterized by the slender body at anterior region, gradually narrowing toward posterior end. Four lines in lateral fields in extremities, increasing to six at mid-body. Deirids at secretory-excretory pore (S-E pore) level and phasmids at 38–62% of the tail. Low-expanded cephalic region having a moderately sclerotized cephalic framework, continuous with body, and not flattened dorso-ventrally. Finely annulated cuticle. Amphidial apertures pore-like. Short (13–15 µm long) stylet, its conus 35–42% of the total length and three small tear-drop like knobs. Pharynx with ellipsoid metacorpus and small valve, small saccate pharyngeal bulb offset from intestine. Reproductive system didelphic-amphidelphic, vulva with no membrane or epyptigma. Tail conical, not elongate or filiform, usually slightly ventrally bent, with a sharp or blunt tip and a small indentation at dorsal side close to tip. Males with similar anterior body region and tail to those of female, tylenchoid spicules and small cloacal bursa. In molecular phylogenetic analyses using partial small and large subunit ribosomal DNA (SSU and LSU rDNA D2-D3) sequences, the new species appeared as an independent lineage between the clades of Hoplolaimina sensu Siddiqi and the clades of Atetylenchus spp. + Psilenchus spp. in the SSU phylogeny. In LSU phylogeny, it placed in a clade including representatives of Atetylenchus, Psilenchus, Amplimerlinius, Pratylenchoides, Nagelus, and Geocenamus. The currently available phylogenies and taxonomic frameworks were re-evaluated for the placement of the didelphic Tylenchidae-like genera, the overall results showing the best resolution is achieved with the family concept of Psilenchidae under Dolichodoroidea.

Volitional Swimming Kinematics of Blacktip Sharks, Carcharhinus limbatus, in the Wild

Recent work showed that two species of hammerhead sharks operated as a double oscillating system, where frequency and amplitude differed in the anterior and posterior parts of the body. We hypothesized that a double oscillating system would be present in a large, volitionally swimming, conventionally shaped carcharhinid shark. Swimming kinematics analyses provide quantification to mechanistically examine swimming within and among species. Here, we quantify blacktip shark (Carcharhinus limbatus) volitional swimming kinematics under natural conditions to assess variation between anterior and posterior body regions and demonstrate the presence of a double oscillating system. We captured footage of 80 individual blacktips swimming in the wild using a DJI Phantom 4 Pro aerial drone. The widespread accessibility of aerial drone technology has allowed for greater observation of wild marine megafauna. We used Loggerpro motion tracking software to track five anatomical landmarks frame by frame to calculate tailbeat frequency, tailbeat amplitude, speed, and anterior/posterior variables: amplitude and frequency of the head and tail, and the body curvature measured as anterior and posterior flexion. We found significant increases in tailbeat frequency and amplitude with increasing swimming speed. Tailbeat frequency decreased and tailbeat amplitude increased as posterior flexion amplitude increased. We found significant differences between anterior and posterior amplitudes and frequencies, suggesting a double oscillating modality of wave propagation. These data support previous work that hypothesized the importance of a double oscillating system for increased sensory perception. These methods demonstrate the utility of quantifying swimming kinematics of wild animals through direct observation, with the potential to apply a biomechanical perspective to movement ecology paradigms.

Development of an Intensity Modulated Total Skin Electron Irradiation Technique

During total skin electron irradiation (TSEI) of the pot-bellied patients, the anterior skin areas other than the abdominal area move away from the treatment machine and receive a different dose than that of the prescribed. In this study intensity modulated total skin electron irradiation (IM-TSEI) technique is developed to eliminate the dose irregularity in anterior skin areas. Tissue equivalence of a black ABS filament for 3D printer was determined. Abdominal phantoms of different thicknesses (3-6-9-12-15 cm) were created by a 3D printer. Characteristics of IM-TSEI technique were defined by determining the properties of Stanford technique. In this technique a new angle pair, 12FF and treatment time were determined based on the thickness of the abdominal region at the anterior beam positions and SSD was adjusted on the sternum point. Since there were no contour irregularities in the posterior treatment positions SSD was adjusted to the posterior waist point as in the Stanford technique, and the treatment angle pair and treatment time which created a homogeneous profile were used. The parameters affected by abdominal thickness were determined and depth-dependent dose change measurements were performed. IM-TSEI application parameters for different abdominal thicknesses were determined by combined dose measurements and calculation of treatment times. Quality assurance was done by TLD skin dose and intra-phantom film measurements for each abdominal thickness added on an anthropomorphic human phantom. Non-parametric two related Wilcoxon signed rank test was used for statistical analysis, p value <0.05 was considered significant. Average percent doses of IM-TSEI and TSEI profiles were 99.7% and 101.5%(p = 0.006), 100% and 96.5%(p = 0.000), 98.7% and 94.7% (p = 0.000), 99.8% and 94.4% (p = 0.000), 98.9% and 93% (p = 0.000) for 3,6,9,12,15 cm thicknesses respectively in favor of IM-TSEI. More homogeneous doses were obtained with IM-TSEI technique. Average skin doses of IM-TSEI and TSEI were 0.971 and 0.998 Gy for 3 cm (p = 0.088), 1.046 and 1.044 Gy for 6 cm (p = 0.737), 1.019 and 1.075 Gy for 9 cm (p = 0.013) , 1.009 and 1.073 Gy for 12 cm (p = 0.007), 1.023 and 1.081 Gy for 15 cm (p = 0.014) respectively. Absolute dose difference between anterior body regions and the treatment dose for IM-TSEI and TSEI were 2.94% and 4.24%, 11.65% and 11.46%, 9.04% and 17.12%, 9.98% and 19.30%, 7.42% and 16.52% for 3,6,9,12,15 cm thicknesses respectively. In IM-TSEI technique the absolute dose differences between the prescribed dose and anterior body region and the average skin dose were lower at abdominal thicknesses of 9 cm and above. TLD measurements also revealed that IM-TSEI technique corrected the dose irregularity in anterior body surface due to abdominal thickness. Although IM-TSEI technique can be used safely in all abdominal thicknesses, it is more advantageous than Stanford technique in abdominal thicknesses of 9 cm and above, so it can be used in pot-bellied patients.

On the structural organization of the bacillary band of Trichuris muris under cryopreparation protocols and three-dimensional electron microscopy

Whipworms of the genus Trichuris are nematode parasites that infect mammals and can lead to various intestinal diseases of human and veterinary interest. The most intimate interaction between the parasite and the host intestine occurs through the anterior region of the nematode body, inserted into the intestinal mucosa during infection. One of the most prominent structures of the nematode surface found at the infection site is the bacillary band, a surface domain formed by a number of cells, mostly stichocytes and bacillary glands, whose structure and function are still under debate. Here, we used confocal microscopy, field emission scanning electron microscopy, helium ion microscopy, transmission electron microscopy and FIB-SEM tomography to unveil the functional role of the bacillary gland cell. We analyzed the surface organization as well as the intracellular milieu of the bacillary glands of Trichuris muris in high pressure frozen/freeze-substituted samples. Results showed that the secretory content is preserved in all gland openings, presenting a projected pattern. FIB-SEM analysis showed that the lamellar zone within the bacillary gland chamber is formed by a set of lacunar structures that may exhibit secretory or absorptive functions. In addition, incubation of parasites with the fluid phase endocytosis marker sulforhodamine B showed a time-dependent uptake by the parasite mouth, followed by perfusion through different tissues with ultimate secretion through the bacillary gland. Taken together, the results show that the bacillary gland possess structural characteristics of secretory and absorptive cells and unequivocally demonstrate that the bacillary gland cell functions as a secretory structure.

Description of Longidorus barsii Radivojević &amp; De Luca sp. n. (Nematoda: Longidoridae) from Serbia and observations on some taxonomic characters

Summary Longidorus barsii sp. n., from Mt Tara in the Balkan Peninsula, is described and characterised by using a polyphasic approach. The species has numerous males. The female body is 5-7 mm long, rather stout and resembles a large Xiphinema. The lip region is wide, with rounded sides continuous with the neck, frontally flattened and depressed around the oral aperture, amphids are pouch-like and distinctly bi-lobed and the odontostyle is moderately long. The nuclei of the pharyngeal glands are in the normal position, the dorsal nucleus located somewhat posterior to anterior third of bulb. The uteri are long, the distal inner epithelium densely covered with papilla-like outgrowths. The tail is rounded, bluntly conoid and very short. Alpha-numerical identification codes: A4/5, B45, C3, D3, E2, F3, G 1(2), H1, I2, J1, K67. The morphologically most similar species are L. kheirii, L. polyae and L. profundorum. Additional observations are provided on the anterior body region and genital organs in L. barsii sp. n., L. piceicola, L. silvae, and L. uroshis. Selected features are discussed from the taxonomic and functional points of view. The D2-D3 expansion domains of the 28S rRNA gene and the ITS region of L. barsii sp. n. were amplified and sequenced. Phylogenetic analysis using the D2-D3 expansion domains of the 28S rRNA gene revealed close evolutionary relationships with L. polyae, L. athesinus and three unidentified Longidorus spp.

Unique morphology and mechanical property of Chinese sturgeon (Acipenser sinensis) fish skin.

Chinese sturgeon (Acipenser sinensis) fish skin is an excellent natural material with remarkable mechanical properties owing to the unique structures of the helical stacking fibres. In this work, the authors studied the potential role of the sturgeon fish skin in the protective function through testing and analysed the structural features and mechanical properties of the stratum compactum in the fish skin. Scanning electron microscopy images of the sturgeon fish skin revealed that the skin was primarily composed of the stratum compactum. The stratum compactum was characterised by the helically arranged fibre structures and the helical-ply angle decreased from the anterior region of the fish body to the posterior region. Mechanical tests containing tension and penetration experiments demonstrated that the stratum compactum provided the sturgeon fish skin the capability to effectively resist bite and laceration by predators. Furthermore, the experimental results also confirmed that the sturgeon fish skin showed two distinct mechanisms against tension and penetration. These findings may provide a novel biomimetic design template for both flexible and tough body armour.

Hox gene expression during development of the phoronid Phoronopsis harmeri

BackgroundPhoronida is a small group of marine worm-like suspension feeders, which together with brachiopods and bryozoans form the clade Lophophorata. Although their development is well studied on the morphological level, data regarding gene expression during this process are scarce and restricted to the analysis of relatively few transcription factors. Here, we present a description of the expression patterns of Hox genes during the embryonic and larval development of the phoronid Phoronopsis harmeri.ResultsWe identified sequences of eight Hox genes in the transcriptome of Ph. harmeri and determined their expression pattern during embryonic and larval development using whole mount in situ hybridization. We found that none of the Hox genes is expressed during embryonic development. Instead their expression is initiated in the later developmental stages, when the larval body is already formed. In the investigated initial larval stages the Hox genes are expressed in the non-collinear manner in the posterior body of the larvae: in the telotroch and the structures that represent rudiments of the adult worm. Additionally, we found that certain head-specific transcription factors are expressed in the oral hood, apical organ, preoral coelom, digestive system and developing larval tentacles, anterior to the Hox-expressing territories.ConclusionsThe lack of Hox gene expression during early development of Ph. harmeri indicates that the larval body develops without positional information from the Hox patterning system. Such phenomenon might be a consequence of the evolutionary intercalation of the larval form into an ancestral life cycle of phoronids. The observed Hox gene expression can also be a consequence of the actinotrocha representing a “head larva”, which is composed of the most anterior body region that is devoid of Hox gene expression. Such interpretation is further supported by the expression of head-specific transcription factors. This implies that the Hox patterning system is used for the positional information of the trunk rudiments and is, therefore, delayed to the later larval stages. We propose that a new body form was intercalated to the phoronid life cycle by precocious development of the anterior structures or by delayed development of the trunk rudiment in the ancestral phoronid larva.

Development of Cerata in the Cladobranchian Sea Slug Pteraeolidia semperi (Mollusca: Gastropoda: Nudibranchia).

Cladobranchian sea slugs are characterized by a number of dorsal projections, called "cerata," which are presumably involved in such biological functions as kleptocnidal defense, gas exchange, and symbiotic photosynthesis. Here, we investigated the developmental pattern of ceras formation in a cladobranchian, Pteraeolidia semperi, using field-collected individuals at various postembryonic developmental stages. As the body length increased, the total number of cerata increased in a logistic manner, up to 280 per individual. On the dorsal side of the body, the cerata exhibited a conspicuous formation of repeated, laterally-paired clusters, or rows, along the antero-posterior axis of the animals. As the body length increased, the number of ceras rows increased in a logistic manner, reaching a plateau at around 15 rows per individual. Two types of ceras clusters were observed: well-developed ceras clusters forming a glove-like structure with a basal bulge, which tended to be found in larger animals and at the anterior body region, and less-developed ceras clusters without the bulge, which tended to be found in smaller animals and at the posterior body region. Statistical and simulation analyses suggested that bulge formation underlies increased ceras number, even after the plateaued formation of new ceras rows. These results indicate that, in the postembryonic development of P. semperi, the increase of dorsal cerata entails the following processes: (i) increase of the number of ceras rows, (ii) formation of the basal bulge in each ceras cluster, and (iii) increase of the number of cerata per ceras cluster.

First evidence of serotoninergic components in the nervous system of the monogenean Chimaericola leptogaster (Chimaericolidae, Polyopisthocotylea), a gill parasite of the relict holocephalan fish.

The localisation and distribution of the serotoninergic nerve elements was studied for the first time in the flatworm Chimaericola leptogaster (Leuckart, 1830) using immunocytochemical methodology and confocal laser scanning microscopy. The musculature was investigated by histochemical staining of actin filaments; scanning electron microscopy was used to identify the sensory structures on the worm's surface. Uniciliated, bi-ciliated and multiciliated sensory endings have been described on the worm's surface. The morphological data demonstrate the presence of circular, longitudinal and diagonal muscles that comprise the musculature of C. leptogaster in the anterior, median and posterior body regions. Well-developed radial and circular muscle fibres were also observed surrounding the genital pore, two vaginae and in clumps of the haptor. The study revealed the presence of biogenic amine, serotonin, in the central and peripheral nervous systems of C. leptogaster: in the neurons and fibres of the cephalic ganglia and ventral nerve cord, in the innervation of reproductive system compartments. The localised sites of the serotoninergic elements point to important roles of serotonin in monogenean reproductive processes and, possibly, in the regulation of muscle function.

Paralogous HOX13 Genes in Human Cancers.

Hox genes (HOX in humans), an evolutionary preserved gene family, are key determinants of embryonic development and cell memory gene program. Hox genes are organized in four clusters on four chromosomal loci aligned in 13 paralogous groups based on sequence homology (Hox gene network). During development Hox genes are transcribed, according to the rule of “spatio-temporal collinearity”, with early regulators of anterior body regions located at the 3’ end of each Hox cluster and the later regulators of posterior body regions placed at the distal 5’ end. The onset of 3’ Hox gene activation is determined by Wingless-type MMTV integration site family (Wnt) signaling, whereas 5’ Hox activation is due to paralogous group 13 genes, which act as posterior-inhibitors of more anterior Hox proteins (posterior prevalence). Deregulation of HOX genes is associated with developmental abnormalities and different human diseases. Paralogous HOX13 genes (HOX A13, HOX B13, HOX C13 and HOX D13) also play a relevant role in tumor development and progression. In this review, we will discuss the role of paralogous HOX13 genes regarding their regulatory mechanisms during carcinogenesis and tumor progression and their use as biomarkers for cancer diagnosis and treatment.

Histological study of the circulatory system of Sulawesi Medaka fish (Oryzias celebensis) for animal model research

Sulawesi medaka fish (Oryzias celebensis) is one part of medaka fish that are endemic in the region of South Sulawesi, Indonesia. This study aims to observe histological structure of the circulatory system of Sulawesi medaka fish. Morphological study showed that the heart is located in the anterior region of the Sulawesi medaka fish body. Histological study of the circulatory of Sulawesi medaka fish showed that the atrium has thin walls whereas the ventricles have thick walls. The contractions of the ventricle have high pressure and then the blood will be pumped through a bulbus arteriosus that is shaped like an onion. Bulbus arteriosus consists of fibroelastic tissue and some smooth muscles. Bulbus arteriosus, is a unique structure and is to dampen the pressure pulse that generated by the ventricle. According to the circulatory system of zebrafish showed that there were similarity between Sulawesi medaka fish and Zebrafish. In general the structure of the circulatory system specially heart and bulbus anteriosus in Sulawesi medaka fish has similarity with Zebrafish as well as other Teleostei fish. This results suggested that Sulawesi medaka fish can be used as model animals especially in the use of fish as animal models in research of cardiovascular disease.