Tbx4 function during hindlimb development reveals a mechanism that explains the origins of proximal limb defects.

We dissect genetically a gene regulatory network that involves the transcription factors Tbx4, Pitx1 and Isl1 acting cooperatively to establish the hindlimb bud, and identify key differences in the pathways that initiate formation of the hindlimb and forelimb. Using live image analysis of murine limb mesenchyme cells undergoing chondrogenesis in micromass culture, we distinguish a series of changes in cellular behaviours and cohesiveness that are required for chondrogenic precursors to undergo differentiation. Furthermore, we provide evidence that the proximal hindlimb defects observed in Tbx4 mutant mice result from a failure in the early differentiation step of chondroprogenitors into chondrocytes, providing an explanation for the origins of proximally biased limb defects.

Tbx5 Buffers Inherent Left/Right Asymmetry Ensuring Symmetric Forelimb Formation.

The forelimbs and hindlimbs of vertebrates are bilaterally symmetric. The mechanisms that ensure symmetric limb formation are unknown but they can be disrupted in disease. In Holt-Oram Syndrome (HOS), caused by mutations in TBX5, affected individuals have left-biased upper/forelimb defects. We demonstrate a role for the transcription factor Tbx5 in ensuring the symmetric formation of the left and right forelimb. In our mouse model, bilateral hypomorphic levels of Tbx5 produces asymmetric forelimb defects that are consistently more severe in the left limb than the right, phenocopying the left-biased limb defects seen in HOS patients. In Tbx hypomorphic mutants maintained on an INV mutant background, with situs inversus, the laterality of defects is reversed. Our data demonstrate an early, inherent asymmetry in the left and right limb-forming regions and that threshold levels of Tbx5 are required to overcome this asymmetry to ensure symmetric forelimb formation.

Etiologies underlying subtypes of long-standing type 2 diabetes.

BACKGROUND: Attempts to subtype, type 2 diabetes (T2D) have mostly focused on newly diagnosed European patients. In this study, our aim was to subtype T2D in a non-white Emirati ethnic population with long-standing disease, using unsupervised soft clustering, based on etiological determinants. METHODS: The Auto Cluster model in the IBM SPSS Modeler was used to cluster data from 348 Emirati patients with long-standing T2D. Five predictor variables (fasting blood glucose (FBG), fasting serum insulin (FSI), body mass index (BMI), hemoglobin A1c (HbA1c) and age at diagnosis) were used to determine the appropriate number of clusters and their clinical characteristics. Multinomial logistic regression was used to validate clustering results. RESULTS: Five clusters were identified; the first four matched Ahlqvist et al subgroups: severe insulin-resistant diabetes (SIRD), severe insulin-deficient diabetes (SIDD), mild age-related diabetes (MARD), mild obesity-related diabetes (MOD), and a fifth new subtype of mild early onset diabetes (MEOD). The Modeler algorithm allows for soft assignments, in which a data point can be assigned to multiple clusters with different probabilities. There were 151 patients (43%) with membership in cluster peaks with no overlap. The remaining 197 patients (57%) showed extensive overlap between clusters at the base of distributions. CONCLUSIONS: Despite the complex picture of long-standing T2D with comorbidities and complications, our study demonstrates the feasibility of identifying subtypes and their underlying causes. While clustering provides valuable insights into the architecture of T2D subtypes, its application to individual patient management would remain limited due to overlapping characteristics. Therefore, integrating simplified, personalized metabolic profiles with clustering holds greater promise for guiding clinical decisions than subtyping alone.

Metal tolerance and biosorption capacities of bacterial strains isolated from an urban watershed.

Rapid industrialization and urbanization have led to widespread metal contamination in aquatic ecosystems. This study explores the metal tolerance and biosorption characteristics of four bacterial strains (Serratia sp. L2, Raoultella sp. L30, Klebsiella sp. R3, and Klebsiella sp. R19) isolated from Saint Clair River sediments. These strains effectively removed various metal cations (As3+, Pb2+, Cu2+, Mn2+, Zn2+, Cd2+, Cr6+, and Ni2+) in single and multi-metal solutions. Minimum inhibitory concentration (MIC) assays revealed strain-specific variations in metal tolerance, with L2 and L30 exhibiting higher tolerance. Surprisingly, R3 and R19, despite lower tolerance, demonstrated superior metal removal efficiency, challenging the notion that tolerance dictates removal efficacy. In single-metal solutions, R3 and R19 excelled at extracting various metal ions, while competitive binding in multi-metal solutions hindered removal. However, R3 and R19 retained higher removal efficiencies, possibly due to enhanced flocculation activities facilitating metal-ion contact. Comprehensive Fourier-transform infrared (FTIR) analysis highlighted the strains' metal-binding capabilities, with novel peaks emerging after metal exposure, indicative of extracellular polymeric substance (EPS) production. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) confirmed metal accumulation on bacterial surfaces and within cytoplasmic regions and revealed morphological changes and metal adsorption patterns, emphasizing the strains' ability to adapt to metal stress. Scanning transmission microscopy (STEM) and EDX analysis uncovered metal accumulation within bacterial cells, underscoring the complexity of microbial-metal interactions. This study also confirms that the simultaneous presence of an aqueous solution may cause a mutual inhibition in the adsorption of each metal to the EPS resulting in reduced metal uptake, which emphasizes the need to select specific bacterial strains for a given metal-containing effluent. The differences in metal distribution patterns between Klebsiella sp. R19 and Raoultella sp. L30 suggest species-specific metal accumulation strategies driven by environmental conditions and metal availability. The heavy metal-removing capabilities and the ability to grow over a wide range of metal concentrations of the strains used in this study may offer an advantage to employ these organisms for metal remediation in bioreactors or in situ.

Risk and predictors of severity and mortality in patients with type 2 diabetes and COVID-19 in Dubai.

BACKGROUND: Globally, patients with diabetes suffer from increased disease severity and mortality due to coronavirus disease 2019 (COVID-19). Old age, high body mass index (BMI), comorbidities, and complications of diabetes are recognized as major risk factors for infection severity and mortality. AIM: To investigate the risk and predictors of higher severity and mortality among in-hospital patients with COVID-19 and type 2 diabetes (T2D) during the first wave of the pandemic in Dubai (March-September 2020). METHODS: In this cross-sectional nested case-control study, a total of 1083 patients with COVID-19 were recruited. This study included 890 men and 193 women. Of these, 427 had T2D and 656 were non-diabetic. The clinical, radiographic, and laboratory data of the patients with and without T2D were compared. Independent predictors of mortality in COVID-19 non-survivors were identified in patients with and without T2D. RESULTS: T2D patients with COVID-19 were older and had higher BMI than those without T2D. They had higher rates of comorbidities such as hypertension, ischemic heart disease, heart failure, and more life-threatening complications. All laboratory parameters of disease severity were significantly higher than in those without T2D. Therefore, these patients had a longer hospital stay and a significantly higher mortality rate. They died from COVID-19 at a rate three times higher than patients without. Most laboratory and radiographic severity indices in non-survivors were high in patients with and without T2D. In the univariate analysis of the predictors of mortality among all COVID-19 non-survivors, significant associations were identified with old age, increased white blood cell count, lym-phopenia, and elevated serum troponin levels. In multivariate analysis, only lymphopenia was identified as an independent predictor of mortality among T2D non-survivors. CONCLUSION: Patients with COVID-19 and T2D were older with higher BMI, more comorbidities, higher disease severity indices, more severe proinflammatory state with cardiac involvement, and died from COVID-19 at three times the rate of patients without T2D. The identified mortality predictors will help healthcare workers prioritize the management of patients with COVID-19.

Combining Topical and Oral Botanicals for Skin Redness, Pigmentation, Sleep, and Mood: A Randomized Controlled Study.

External and internal stressors have been found to adversely affect skin health and overall wellness. There is growing interest in the use of anti-inflammatory and antioxidant plant-derived ingredients, such as ashwagandha, saffron, l-theanine, and tocopherol, to mitigate the impact of these stressors. In this study, we evaluate the effectiveness of oral and topical products (InnerCalm and SuperCalm, respectively) that contain naturally derived ingredients on skin redness, skin pigmentation, sleep, and mood in healthy females with Fitzpatrick skin type 1−4 and self-perceived sensitive skin. Subjects were randomized to an oral (oral group), a topical (topical group), or a combination of both the oral and topical interventions (combined group). Standardized photography-based image analysis was used to assess skin redness and pigment. Self-assessments of mood and sleep were measured with the abbreviated profile of mood states (POMS) questionnaire, and the Pittsburgh sleep-quality index (PSQI), respectively. Assessments were made at the baseline, 1-week, 4-weeks, and 8-weeks of the intervention. The average facial redness decreased in the topical group at 8-weeks (p < 0.001) and in the combined group at 4-weeks (p < 0.05) and 8-weeks (p < 0.001), relative to the baseline. The average facial pigmentation decreased in the oral (p < 0.05) and combined (p < 0.05) cohorts at 8-weeks, relative to the baseline. The oral group exhibited an improvement in sleep quality at 1-week relative to the baseline (p < 0.05) and at 8-weeks relative to the baseline (p < 0.05). Finally, the combined group demonstrated improvement in fatigue (p < 0.01) and confusion (p < 0.05) at 8-weeks relative to the baseline, though total mood disturbance increased in all 3 groups over the course of the study. Measured outcomes relating to mood may be confounded with the timing of the study, which ran during the COVID pandemic. Overall, we demonstrate the role of oral and topical herbs and of nutraceuticals for skin health and wellness. Further research will be needed to elucidate synergistic effects in oral and topical combination regimens.

Melatonin ameliorates some biochemical alterations following ketoconazole administration in rats.

Background Ketoconazole (Keto), an antifungal drug and a common therapeutic option in the treatment of advanced prostate cancer, is known to cause reproductive dysfunctions. Like Keto, melatonin has antifungal and anticarcinogenic actions. Moreover, the hormone has been used to reverse the damaging effects of different toxicants on the reproductive system. Therefore, this study investigated the effects of Keto with/without melatonin on selected biomarkers in rats. Methods Forty rats of 10 animals per group were used in this study, which lasted for 6 weeks. The control group was administered with saline (0.1 mL/day), while group 2 was administered with Keto during the last 3 weeks of experiment; however, in groups 3 and 4, Keto was administered during the first 3 weeks; thereafter, they were administered with saline and melatonin, respectively, during the subsequent 3 weeks. Keto and melatonin were administered at 100 and 10 mg/kg b.w./day (p.o.), respectively. Results The central effects of Keto are independent of the follicle stimulating hormone (FSH) and prolactin; however, relative to the control group, the drug significantly decreased the gonadotrophin releasing hormone (GNRH) and the luteinizing hormone (LH), substantiated by the corresponding significant decreases in sperm count and sperm morphology. Keto caused significant elevations in malondialdehyde (MDA) and lactate dehydrogenase (LDH) and a significant decrease in catalase (CAT) compared with the control group. Moreover, the drug triggered pro-inflammatory events. In group 3 (Keto recovery), MDA and uric acid levels were returned to the baseline (i.e. control), but not GNRH, LH, C-reactive protein (CRP), LDH, and CAT. Treatment with melatonin after Keto administration caused significant increases in FSH, LH, superoxide dismutase, total antioxidant capacity (TAC), sperm count, and sperm morphology but significant decreases in MDA and CRP, relative to groups 2 and 3. Conclusions Melatonin ameliorates some biochemical alterations following ketoconazole administration.