Seasonal variations and associated health risks of polychlorinated naphthalenes in Markman Canal, Eastern Cape Province, South Africa.

This study focused on evaluation of the levels, seasonal variations and human health risks associated with polychlorinated naphthalenes (PCNs) in water and sediment samples of Markman Canal using solid phase and soxhlet extraction methods respectively, followed by clean-up and quantification with gas chromatograph coupled with microelectron capture detector. The sum of eight PCNs congener's (∑8PCNs) in water and sediments varied from 0.035 to 0.699 µg/L and 0.260 to 6744.16 µg/kg dw, respectively. Highest PCNs concentrations were recorded in water during winter, while sediment samples collected during spring contained maximum levels. The estimated toxic equivalency (TEQ) for water and sediments was 1.19 × 10-7-1.47 × 10-4 µg/L and 4.43 × 10-5-4.19 × 10-1 µg/kg consecutively. The PCN levels and TEQ values revealed that this waterbody is polluted but constitutes no excess health risk. Efforts should be made to control all the activities contributing to pollution of this canal.

Chemerin Levels in Individuals with Type 2 Diabetes and a Normal Weight versus Individuals with Type 2 Diabetes and Obesity: An Observational, Cross-Sectional Study.

Chemerin acts as both a chemotactic agent and an adipokine that undergoes proteolytic cleavage, converting inactive precursors into their active forms before being subsequently inactivated. Elevated chemerin levels are linked to obesity and type 2 diabetes mellitus (T2D). This study aimed to elucidate the effects of T2D and obesity on chemerin levels by comparing plasma samples from individuals with a normal weight and T2D (BMI < 25; NWD group n = 22) with those from individuals who are overweight or obese and have T2D (BMI ≥ 25; OWD group n = 39). The total chemerin levels were similar in the NWD and OWD groups, suggesting that T2D may equalize the chemerin levels irrespective of obesity status. The cleavage of chemerin has been previously linked to myocardial infarction and stroke in NWD, with potential implications for inflammation and mortality. OWD plasma exhibited lower levels of cleaved chemerin than the NWD group, suggesting less inflammation in the OWD group. Here, we showed that the interaction between obesity and T2D leads to an equalization in the total chemerin levels. The cleaved chemerin levels and the associated inflammatory state, however, differ significantly, underscoring the complex relationship between chemerin, T2D, and obesity.

Audiometric and Otologic Findings in Children and Young Adults with Neurofibromatosis Type 1 and Plexiform Neurofibromas.

OBJECTIVES: To characterize otologic and audiologic manifestations in our NF1 cohort and explore the relationship between otologic and audiologic findings in a subset of patients with ear-related plexiform neurofibromas (PNs). METHODS: Audiologic and otologic clinical evaluations were conducted on 102 patients with NF1 in a natural history study (5-45 years; M = 14.4 years; Mdn = 14). Testing included pure tone and speech audiometry, middle ear function, neurodiagnostic auditory brainstem response (ABR), auditory processing, and MRIs of the head and neck region. Patients referred to this study had an overall higher incidence and burden of PNs than the overall NF1 population. RESULTS: The majority of subjects in this cohort had normal hearing sensitivity (81%) and normal middle ear function (78%). Nineteen participants had hearing loss that ranged in degree from mild to profound, with the majority in the mild range. Hearing loss was twice as likely to be conductive than sensorineural. In patients with ear-related PNs (n = 12), hearing loss was predominantly conductive (60%). Seventy-five percent of ears with PNs had atypical tympanometric tracings that could not be characterized by the classic categories. In all 20 patients with a PN in the temporal bone, the ear canal was affected, and the PNs often extended to the surrounding soft tissue regions. CONCLUSIONS: People with NF1-related PNs in the temporal bone and adjacent skull base should have audiometric and otologic monitoring. Addressing hearing concerns should be part of routine clinical evaluations in patients with NF1. Magnetic resonance imaging (MRI) should be performed in patients with NF1 who have hearing loss. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:2770-2778, 2023.