The function of the parathyroid gland in the regulation of serum calcium in the salamander, Tylototriton andersoni Boulenger (2023)

i salamanders,Cynopus pyrrhogaster, parathyroidectomy (PTX) produced a significant decrease in plasma calcium concentration. Animals recovered from hypocalcemia 15 days after surgery if the pituitary gland remained intact. After PTX, no significant changes in plasma sodium concentration were observed. Experiments were then performed to obtain direct evidence that endogenous prolactin (PRL) is involved in this recovery process. The recovery of calcium levels after PTX was prevented by the administration of a salamander PRL antiserum. In salamanders deprived of pituitary and parathyroid glands, no recovery from hypocalcemia was observed. Administration of salamander or sheep PRL to salamanders with parathyroid hypophysectomization significantly increased blood calcium levels. After PTX, the concentration of immunoassayed PRL in the blood increased to 10 times the value in sham-operated animals. These results indicate the involvement of PRL in calcium homeostasis in parathyroid hormone-deficient salamanders.

Plasma calcium concentrations of parathyroidectomized male specimens of green grog,screaming seed, were followed up for 44 or 62 weeks. Plasma levels of total and ionized calcium in parathyroidectomized animals decreased by 31-53% at 3 days, continuing to decrease to ca. 50% of preoperative levels at weeks 3-9 and remained at these low levels throughout the experiments. Plasma levels of sodium, pH and hematocrit remained unchanged. Chronic hypocalcemia resulted in tetanic seizures in all long-term parathyroidectomized animals and death in most long-term parathyroidectomized animals. Thus, in the green frog, the presence of the parathyroid gland is necessary to maintain blood calcium levels and survive.

Hypophysectomized red spot salamanders showed hyponatremia but not hypocalcemia. Parathyroidectomy and a combination of hypophysectomy and parathyroidectomy caused a fall in plasma calcium levels, but control levels were restored within 12 days. Injections of ovine prolactin had no effect on plasma calcium or sodium levels in sham-operated, parathyroidectomized salamanders conditioned in tap water or 0.6% sodium chloride solution containing 10 meq of calcium/liter. These data indicate that the pituitary is not involved in the hypercalcemic regulation of the red-spotted salamander.

Your parathyroid glandsDesmognathus monticolathey are located in the subcutaneous connective tissue of the neck. Although they are smaller than the previously described parathyroid glands, their histological structure is similar. Parathyroidectomy caused a decrease in plasma calcium concentrations within 4 days after surgery. However, on days 12 and 21, plasma calcium levels of parathyroidectomized animals did not differ significantly from operated animals. Thus, the parathyroid gland of this species contains a hypercalcemic principle, but recovery from hypocalcemia suggests that some hypercalcemic mechanism outside the parathyroid system must be involved in calcium homeostasis.

Biological Conservation, bond 219, 2018, s. 96-104

In rice fields, the cultivated area itself can play a significant role as a habitat for wetland organisms. Many previous studies have shown a negative impact of agricultural intensification and abandonment on the biodiversity of wetland ecosystems. However, there is still verification of the direct impact of changes in the aquatic environment resulting from the improvement and abandonment of rice paddies. Here, we investigate the effects of intensification and abandonment on the remaining wetland area in rice paddies during fallow, as well as the factors leading to population decline in the Japanese brown frog (japanese seed), using data from long-term monitoring of egg mass counts at various sites. To quantify spatial and temporal variation in water-saturated areas in rice fields where frogs spawn in early spring, we used infrared bands from Landsat images. Both the improvements and the abandonment of the rice fields affectedJapanese R.populations by reducing wetland areas in fields. Furthermore, seed population size was positively correlated with the surrounding forest area. Our results suggest that conservation in wetlands requires adequate water management in the growing area, as well as in other landscape elements that serve as secondary habitats.

Machine learning with apps, link 7, 2022, article 100202

Frogs play an important role in ecological systems and frog species across the world are threatened and in decline. Therefore, it is valuable to estimate the seed stock of an intelligent computer system. Due to the success of deep learning (DL) in various pattern recognition tasks, previous studies have used DL-based methods to analyze frog calls. However, the performance of DL-based systems is heavily influenced by their input (feature representation). In this study, we developed a frog call activity detection system for continuous field recordings using a lightweight convolutional neural network (CNN) with multiview spectrograms. More specifically, a sliding window is first applied to continuous recordings to capture fixed-length audio segments. Background noise is then filtered out. A multi-view spectrogram is then used to characterize these segments, which have more discriminative information than a single-view spectrogram. Finally, a lightweight CNN model is used to detect double-loss seed call activity, where different training and testing sets are used to validate the robustness of the model. Our experimental results indicate that the highest F1 macro score was 99.6±0.2 and 96.4±2.0 using 2016 and 2017 as train data, respectively, where CNN-GAP is used as a multiprojection spectrogram model as input.

Pharmacological Research, Volume 147, 2019, Article 104350

Osteoporosis and osteopenia affect more than 54 million Americans, resulting in significant morbidity and mortality. Alterations in bone remodeling are characteristic of osteoporosis and, therefore, the development of new therapies to prevent or treat bone diseases will be clinically important and will improve the quality of life of these patients. Bone remodeling involves the removal of old bone by osteoclasts and the formation of new bone by osteoblasts. This process is closely related and essential to maintain bone strength and integrity. Since the osteoclast is the only cell capable of bone resorption, the development of drugs to treat bone disorders has a primary focus on reducing osteoclastic differentiation, maturation and bone resorption mechanisms, and there are few treatments that actually increase bone formation. Evidence from observational, experimental, and clinical studies shows a positive relationship between natural compounds and improved markers of bone health. While many natural extracts and compounds have beneficial effects on bone, only resveratrol, sulforaphane, specific phenolic acids, and anthocyanins have been shown to increase bone formation and decrease resorption through their effects on the bone epigenome. Each of these compounds alters specific aspects of the bone epigenome to increase osteoblast differentiation, reduce osteoblast apoptosis, increase bone mineralization, and reduce osteoclast differentiation and function. This review focuses on these specific natural compounds and their epigenetic regulation of bone turnover.

Developmental Biology, Volume 451, Issue 2, 2019, pp. 146-157

Some organisms, like the Mexican axolotl, have the ability to regenerate complex biological structures throughout their lives. Which molecular pathways are sufficient to induce a complete endogenous regenerative response in injured tissue is an important question that remains unanswered. Using a gain-of-function regeneration analysis known as the Accessory Limb Model (ALM), we and others have begun to identify the molecular underpinnings of the three key requirements for limb regeneration. injury, neurotrophic signaling, and pattern induction of cells that maintain location memory. We have previously shown that treatment of Mexican axolotls with exogenous retinoic acid (RA) is sufficient to induce the formation of complete limb structures from blastomas generated by ablation of a bundle of nerves at a wound site located in the anterior part of the limb. Here we show that these ectopic structures are able to regenerate and induce new patterns when transplanted into new previously located lesions. We also found that the expressionAlx4cai eSssExpression is increased in these anterior blastomas but not in mature anterior tissue, supporting the hypothesis that RA treatment subsequently degrades blastoma tissue. Based on these and previous observations, we used the ALM trial to test the hypothesis that a complete regenerative response can be generated by treating superficial anterior cingulate wounds with a specific combination of growth factors at defined developmental stages. Our data show that limb ulcers initially treated with a combination of FGF-2, FGF-8 and BMP-2, followed by RA treatment of the resulting blastema in the mid-eye stage, will result in limbs with proximal/distal and anterior injury. /previous complete. hindlimb axes. Minimal nerve signal requirements and a difference in position are thus achieved using this particular combination of signal molecules.

Development Cell, Volume 39, Issue 4, 2016, pp. 411-423

Connective tissue - skeleton, dermis, pericytes, fascia - is an important cellular source for patterned skeletal regeneration during axolotl appendage regeneration. This complexity made it difficult to identify the cells that regenerate skeletal tissue. The inability to identify these cells has hindered the mechanistic understanding of blastema formation. By tracking cells during fingertip regeneration using transgenic cerebral axolotls, we show that cells from each connective tissue compartment have different spatial and temporal profiles of proliferation, migration and differentiation. Chondrocytes proliferate but do not migrate during regeneration. Instead, pericytes proliferate, then migrate to the blastoma and give rise exclusively to pericytes. Periskeletal cells and fibroblasts contribute to the volume of finger blast cells and reach different destinations according to successive waves of migration that choreograph their proximal-distal and tissue contributions. We further show that platelet-derived growth factor signaling is a potent inducer of fibroblast migration, required to form the blastema.

Animal Behavior, binding 187, 2022, s. 121-135

Carotenoids play an important role as one of the most abundant pigments in animals. Carotenoid-based coloration is responsible for impressive sexual and naturally selected color adaptations. Many anurans (frogs and toads) change body color slowly and permanently between life stages (ontogenetic color change) or quickly and temporarily within minutes or hours (dynamic color change). We investigated the ontogenetic color change from orange to green in Wallace's flying frog,Rhacophorus nigropalmatusand investigated the effect of dietary carotenoids on color change during postmetamorphic development. At 9 months of age, while all individuals still had an orange-red body color, a 20-week feeding experiment was conducted feeding the frogs no carotenoid supplements or dietary carotenoids once or four times a week. A carotenoid-rich diet resulted in a more rapid increase in green color, as well as higher levels of green and carotenoid coloration on the back. Less or no carotenoid supplementation led to an increase in UV-blue color, contributing to a dull turquoise appearance often seen in captive and captive-bred anurans. Furthermore, we show for the first time that Wallace's flying frogs also perform dynamic color changes. We tested dynamic changes induced by 2-minute touch manipulation or 1-hour alternating dark and light conditions. Our results show that a carotenoid-rich diet facilitates a rapid and reversible change in body color in response to a tactile stressor, an adaptation absent in carotenoid-depleted frogs. Dynamic color changes were also observed in response to changes in light conditions, apparently camouflaging individuals and providing UV protection. The ontogenetic and dynamic alterations of pigmentation are discussed in relation to the mechanism and as a possible strategy to avoid predation at different life stages and in different environments.