Cadmium (Cd) is a heavy metal toxicant as a common pollutant derived from many agricultural and industrial sources. The absorption of Cd takes place primarily through Cd-contaminated food and water and, to a significant extent, via inhalation of Cd-contaminated air and cigarette smoking. Epidemiological data suggest that occupational or environmental exposure to Cd increases the health risk for osteoporosis and spontaneous fracture such as itai-itai disease. However, the direct effects and underlying mechanism(s) of Cd exposure on bone damage are largely unknown. We used primary bone marrow-derived mesenchymal stromal cells (BMMSCs) and found that Cd significantly induced BMMSC cellular senescence through over-activation of NF-κB signaling pathway. Increased cell senescence was determined by production of senescence-associated secretory phenotype (SASP), cell cycle arrest and upregulation of p21/p53/p16ᴵᴺᴷ⁴ᵃ protein expression. Additionally, Cd impaired osteogenic differentiation and increased adipogenesis of BMMSCs, and significantly induced cellular senescence-associated defects such as mitochondrial dysfunction and DNA damage. Sprague-Dawley (SD) rats were chronically exposed to Cd to verify that Cd significantly increased adipocyte number, and decreased mineralization tissues of bone marrow in vivo. Interestingly, we observed that Cd exposure remarkably retarded bone repair and regeneration after operation of skull defect. Notably, pretreatment of melatonin is able to partially prevent Cd-induced some senescence-associated defects of BMMSCs including mitochondrial dysfunction and DNA damage. Although Cd activated mammalian target of rapamycin (mTOR) pathway, rapamycin only partially ameliorated Cd-induced cell apoptosis rather than cellular senescence phenotypes of BMMSCs. In addition, a selective NF-κB inhibitor moderately alleviated Cd-caused the senescence-related defects of the BMMSCs. The study shed light on the action and mechanism of Cd on osteoporosis and bone ageing, and may provide a novel option to ameliorate the harmful effects of Cd exposure.

The relationship between pollution level in estuarine sediment and fluctuating asymmetry (FA) of resident smooth toadfish Tetractenos glaber was evaluated. A total of 188 fish from Sydney and Hawkesbury River estuaries (5 locations from each) were analysed for 28 bilateral skull bone characters. Sediment pollution was quantified based on analysis of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) and organochlorine pesticides (DDT, DDD, DDE, chlordane, dieldrin, lindane). Sediment toxicity was characterized using the mean quotient approach (MERMQ) and ranged from low to moderate level for heavy metals and from low to severe for organochlorides. The mean shape and directional asymmetry of fish bones differed among locations, suggesting a response to local environments. FA was positively correlated with organochlorine pesticides across locations, but not with heavy metals. These results suggest that fish FA could be a useful estimator of stress caused by organic toxicity based on the MERMQ approach.

Pregnancy and feto-gestational toxicities on exposure to fluoride and its possible amelioration on co-administration with aloe vera were studied in pregnant Swiss albino mice. Once the confirmed pregnancy was tested, animals were equally divided into four groups as follows: group I was given no treatment and served as control, and groups II and III were administered with 100 and 300 ppm sodium fluoride, respectively, while group IV was co- administered aloe vera (300 mg/kg bw) along with sodium fluoride (300 ppm) daily for 14 days prior to gestation and continued till the 18th day of gestation. Animals were sacrificed on the 19th day of gestation for prenatal observations. Maternal body weight, the gravid uterine weight, number of corpora lutea in both the ovaries, number of implantations and resorptions, number of live (mature and immature) fetuses, and number of dead fetuses were examined in each dam. The treatment continued in another set of animals till the completion of the weaning period to observe postnatal changes due to test substances on the mother and pups. Sodium fluoride–treated animals showed morphometric and skeletal changes which were more pronounced in the high-dose group showing significantly decreased body weight gain in pregnant mothers and dead/immature fetuses. Morphometric changes included open eyelids, limb defects, wrinkles on the whole body, anophthalmia, pulmonary edema, enlarged esophagus, and decreased body weight of fetuses and pups. Alizarin-prepared skeletal structures of fetuses of such female mice showed delayed ossification or bending in the number of bones of skull, thoracic, and limb regions. However, concomitant exposure to sodium fluoride and aloe vera in treated animals led to a marked improvement in all the prenatal and postnatal variables. The study suggests that sodium fluoride at high concentrations may be teratogenic while co-administration of aloe vera during fluoride exposure might be beneficial in reducing these toxic effects. The use of aloe vera as a preventive agent or as a complimentary agent is thus recommended following fluoride exposure through the oral route.

Flash floods represent a serious threat to wildlife, water biota, and human life in pre-alpine regions, particularly in recent historical memory. The alpine bullhead is an established bioindicator of water quality in mountain streams, which can be adversely affected by an increased propensity for flash flooding. The aim of this study was to examine the effect of flash flooding on the variation of chemical elements found in the skull of alpine bullheads, with a focus on inter-annual effects. Their bone tissue reflects an increased concentration of K and Cl and a decreased concentration of biogenic Cr, Zn, and Mo, absorbed mainly through the gills, for up to 2 years following a flood. During autumn, following a summer flash flood, the amount of Mn and Fe present in skull tissues of fish was found to have increased, tapering off again over the following year. These metals are predominantly ingested by bullheads while feeding. The lack of specific types of biogenic concentration in the water may be critical to the definition of presence/absence patterns, as populations were shown to decline 2 to 3 years post-flood. Pre-alpine streams are particularly susceptible to this type of flooding. The decreases in biogenic elements and increase of K and Cl exhibited in bullhead tissues indicate that a negative ecological footprint due to flash floods can still be observed several years following the event.

The aim of this study was to examine the contents of calcium, chlorine, chromium, iron, manganese, molybdenum, potassium, rubidium, strontium, sulfur, tin, and zinc in the bones of the alpine bullhead (Cottus poecilopus) related to its vertical distribution in the mountain river Javorinka. This river is located on the northern side of the High Tatras, the West Carpathians. Sampling took place during 2017, 2018, and 2019. One hundred three individuals of bullheads were collected. Only deceased individuals were selected for sampling; there was no deliberate harm to any sampled individuals. Weight, body length, and head length and width were measured. The amounts of Ca, Rb, and Mo were significantly dependent on the altitude and the fish size. At higher altitudes, there are smaller fish that colonize more inaccessible waters with smaller habitat flow options and these smaller fish contain relatively more Ca, Rb, and Mo in their skulls than large fish. The presence of Mn, Sr, and Zn was related to the altitude. Concentrations of Zn and Sr increase with altitude in the alpine bullhead skulls. The amounts of S, Cl, K, Cr, Sn, and Mo did not differ among fish living at different elevations.

Diamond-like carbon (DLC) and titanium-doped DLC coatings were prepared by hybrid PECVD/direct current magnetron sputtering (DCMS). In this study, we show that the operating conditions of titanium-doped DLC coatings used for implants in surgical devices significantly modify their surface properties and consequently their interaction with cells. The coatings showed uniform distribution on the substrate and their biocompatibility was tested by way of rat calvaria osteoblasts. Doping DLC with Ti changed the roughness and wettability of the film interface. The autoclaving of the samples led to the surface oxidation and the formation of TiO₂ on the top-most layers of Ti-doped DLC. This was quantitatively assessed by X-ray photoelectron spectroscopy (XPS) and revealed the presence of Ti³⁺ and Ti⁴⁺ species in redox reactions during their interactions with cells. By XPS analysis, the oxidative carbonaceous species C=O and O=C–C were detected during the bacterial inactivation. Reactive oxygen species (ROS) were identified on the sputtered samples and the ⦁OH radical was identified as the most important oxidative radical intermediate leading to bacterial disinfection. The position of the intra-gap of the oxidized C species is suggested within the TiO₂ bandgap.