Cellular responses of normal human osteoblasts to multiple environmental stressors in vitro / Aisha Mohd Din

Cells respond to environmental stress via the activation of various survival pathways and may possibly end with the initiation of cell death in order to eliminate damaged cells. The ability of cells to mount an adaptive or destructive response depends on the type and duration of the stress. The response to continuous orbital fluid shear stress (OFSS), moderate hypothermia (35°C) and moderate hyperthermia (39°) in this study demonstrated an anabolic effect on Normal Human Osteoblast (NHOst) cells where the cell metabolism, differentiation and proliferation was either promoted or retained. The anabolic effect correlated with an inhibition of osteoclast activity by reducing the RANKL/OPG ratio. In response to 3 days of OFSS, increase in NHOst mitochondrial metabolism and proliferation simultaneously prevented apoptosis. Meanwhile the increase in alkaline phosphatase (ALP) activity and osteocalcin (OCN) after recovery from OFSS suggested that NHOst function was promoted. The possible mechanism for the transduction of these anabolic signals might have been generated through the actin fibres of the cell's cytoskeleton. On the other hand, when NHOst were exposed to temperature stress for 1 h (acute), 12 h & 24 h (short) and 72 h (prolonged), cells responded by expressing heat or cold shock proteins according to hypo- and hyperthermia severity and exposure duration. Exposure to acute 1 h temperature stress lead to an overall reduction in NHOst metabolism, mRNA and protein expression. Overexpression of Rbm3 and Hsp70 promoted NHOst viability and proliferation in response to short and prolonged moderate hypo- and hyperthermia but not in severe exposure. Up regulation of Rbm3 was involved in the adaptation of NHOst survival while Cirbp was to inhibit NHOst survival. Despite NHOst were progressing in the cell cycle in response to moderate hypothermia, the percentage of NHOst undergoing apoptosis was slightly higher compared to NHOst under severe hypothermia. Both moderate and severe hypothermia showed apoptosis was activated via a caspase 3-independent pathway. Insignificant up regulation of caspase 8 and 9 under moderate hypothermia led to the activation of caspase 3, suggesting both extrinsic and intrinsic pathway was activated. Detachment of NHOst from the culture substratum in response to severe hyperthermia suggests that anoikis as a form of apoptosis was induced. The expression of ALP and OCN was dependent on the expression of Runx2. Meanwhile the overexpression of osterix showed that response to moderate hyperthermia in particular suggests that NHOst have the capability to mature. Prolonged exposure to moderate hypothermia promoted mineral deposition required for bone mineralization as the calcium nodules were slightly larger compared to control. In conclusion, continues exposure to OFSS and short term moderate hypo- and hyperthermia promote if not retains bone functionality in vitro

Adapting Medical Museums: Technology, Education, and Research

In Malaysia, medical museums are transforming, extending their reach beyond conventional medical student training to encompass public education and health awareness. This modernisation incorporates cutting-edge technologies such as 3D printing, QR codes, augmented reality, diversified exhibitions, and hands-on learning experiences. The overarching goal is to captivate a broader audience while advancing medical research and public health education. To achieve this, strategies like interactive exhibits and multi-sector collaborations are employed. This study explores the role of medical museums and the impact of technological innovations on visitor experience and engagement

Assessing Idiopathic Scoliosis Knowledge Levels Among Malaysian Physiotherapists and Associating Their Clinical Experience

Physiotherapists play a significant role in the conservative management of idiopathic scoliosis (IS) patients. This study aimed to determine the level of knowledge on IS among practising physiotherapists and the association between years of clinical experience and the level of knowledge. A total of 63 physiotherapists responded to the International Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SORSOT) questionnaire. The findings demonstrated that the level of knowledge among the physiotherapists was poor, particularly regarding the prevalence, diagnosis, and treatment of IS. There was a significant association between years of clinical experience and the level of knowledge

Mild hyperthermia (39°C) attenuates berberine chloride cytotoxicity against osteosarcoma cells

Many studies reported that antioxidants and dietary supplements increase tumour progress and reduce survival. Hyperthermia is an adjuvant treatment to sensitise cancer cells for radio- or chemotherapy. The current study was carried out to determine the effects of berberine chloride and hyperthermia on bone cancer cells. MG-63 osteosarcoma cells were treated with hyperthermia (39, 43 and 45°C, respectively) for 1 h. Then, the cells were treated with a low toxic dose of berberine chloride (80 μg/mL). After that, all treated groups were recovered at 37°C for 24 h. Finally, all groups were treated with hyperthermia (39, 43 and 45°C) for the second time (1 h) and were recovered for 3 h at 37°C. Cells exposed to hyperthermia without treatment of berberine chloride were used as hyperthermia control. Cells treated with 80 μg/mL of berberine at 37°C served as berberine control and cells incubated at 37°C were used as an untreated control. All treated groups showed significant apoptosis compared to the control group (p<0.05) except 39°C. On the other hand, mild hyperthermia treatment (39°C) resulted in a reduction of berberine-induced apoptosis (p<0.001). Severe and moderate hyperthermia did not show a significant increase in the rate of apoptosis compared to berberine treated cells. Mild hyperthermia treatment can effectively reduce berberine cytotoxicity and implying negative effects on cancer therapy

Phylogenetic classification of the world's tropical forests

Knowledge about the biogeographic affinities of the world’s tropical forests helps to better understand regional differences in forest structure, diversity, composition, and dynamics. Such understanding will enable anticipation of region-specific responses to global environmental change. Modern phylogenies, in combination with broad coverage of species inventory data, now allow for global biogeographic analyses that take species evolutionary distance into account. Here we present a classification of the world’s tropical forests based on their phylogenetic similarity. We identify five principal floristic regions and their floristic relationships: (i) Indo-Pacific, (ii) Subtropical, (iii) African, (iv) American, and (v) Dry forests. Our results do not support the traditional neo- versus paleotropical forest division but instead separate the combined American and African forests from their Indo-Pacific counterparts. We also find indications for the existence of a global dry forest region, with representatives in America, Africa, Madagascar, and India. Additionally, a northern-hemisphere Subtropical forest region was identified with representatives in Asia and America, providing support for a link between Asian and American northern-hemisphere forests.</p

Severe Hyperthermia Induces Apoptosis Mediated by Caspases Activation and Suppression of Hsp90-alpha Expression in Osteosarcoma Cells

BACKGROUND: Hyperthermia is used as an adjuvant treatment to sensitize cancer cells to subsequent radiotheraphy or chemotherapy. The aim of this study was to study the effect of severe hyperthermia on osteosarcoma cells and its underlying causes.METHODS: Short-term (1 h) severe hyperthermia (45°C) was applied to osteoblast-like osteosarcoma cells (MG-63) and the heat shock response and cell death mechanisms were investigated after recovery at 37°C for 72 h.RESULTS: Cell viability was significantly reduced (p<0.05) and apoptosis was significantly induced by severe hyperthermia in MG-63 cells (p<0.001). Caspase 3/7, 4 and 12 activities were significantly increased after 72 h of recovery at 37°C, indicating that severe hyperthermia induced endoplasmic reticulum (ER) stress and apoptosis (p<0.05). Heat shock protein 90 alpha (Hsp90α) was significantly down regulated at the protein level after recovery, in association with apoptosis induction (p<0.01). Additionally, caspase 8 and 9 were activated, possibly as a result of ER stress or other stimuli while, B-cell leukemia 2 family protein (BCL-2) mRNA was down regulated (p<0.01).CONCLUSION: Severe hyperthermia could cause prolonged cell cytotoxicity by inducing apoptosis in association with inhibition of Hsp90α. This indicates the therapeutic potential of severe hyperthermia for the treatment of osteosarcoma.KEYWORDS: hyperthermia, apoptosis, endoplasmic reticulum, stress, heat shock proteins, osteosarcom