Impact of housing temperature on adipose tissue HDAC9 expression and adipogenic differentiation in high fat-fed mice.

OBJECTIVE: Impaired adipogenic differentiation exacerbates metabolic disease in obesity. This study reported that high-fat diet (HFD)-fed mice housed at thermoneutrality exhibited impaired adipogenic differentiation, attributed to increased expression of histone deacetylase 9 (HDAC9). However, the impact of HFD on adipogenic differentiation is reportedly variable, possibly reflecting divergent environmental conditions such as housing temperature. METHODS: C57BL/6J (wild-type [WT]) mice were housed at either thermoneutral (28-30°C) or ambient (20-22°C) temperature and fed HFD or chow diet (CD) for 12 weeks. For acute exposure experiments, WT or transient receptor potential cation channel subfamily M member 8 (TRPM8) knockout mice housed under thermoneutrality were acutely exposed to ambient temperature for 6 to 24 h. RESULTS: WT mice fed HFD and housed at thermoneutrality, compared with ambient temperature, gained more weight despite reduced food intake. They likewise exhibited increased inguinal adipose tissue HDAC9 expression and reduced adipogenic differentiation in vitro and in vivo compared with CD-fed mice. Conversely, HFD-fed mice housed at ambient temperature exhibited minimal change in adipose HDAC9 expression or adipogenic differentiation. Acute exposure of WT mice to ambient temperature reduced adipose HDAC9 expression independent of sympathetic ß-adrenergic signaling via a TRPM8-dependent mechanism. CONCLUSIONS: Adipose HDAC9 expression is temperature sensitive, regulating adipogenic differentiation in HFD-fed mice housed under thermoneutrality.

Identification and Management of Acute Neuromuscular Respiratory Failure in the ICU.

Respiratory failure is a common and potentially life-threatening complication of neuromuscular diseases. Prompt recognition and accurate diagnosis of new or worsening chronic neuromuscular disease have important clinical management and prognostic implications. In this article, we present an approach to the acute presentation of undifferentiated neuromuscular respiratory failure in the ICU and guidance for determination and respiratory management of the underlying disorder.

Accidental Acetone Ingestion in Liver Transplant Patient With Alcohol Relapse: A Case Report.

Acetone is one of the three main types of ketone bodies that can be found in ketoacidosis, along with acetoacetate, and beta-hydroxybutyrate. Any of these three ketone bodies can be found in the blood after the natural breakdown of fatty acids in diabetes, starvation, or alcoholic ketoacidosis. However, a patient can also develop acetone poisoning from ingestion of common household products such as nail polish removers, paint removers, isopropyl alcohol, or other detergents and cleaners. Ingestion is usually accidental in adults and children and can lead to severe damage to the liver, heart, nervous system, and kidneys. In rare cases, large amounts of ingestion can lead to life-threatening conditions or death. Our case reports a man with a history of alcoholic cirrhosis status post liver transplantation, who unintentionally ingested acetone, mistaking the contents of small bottles for vodka. The patient presented with several syncopal episodes, anion gap metabolic acidosis, transaminitis with hyperbilirubinemia, and pancreatitis.

Diagnosis and Management of Rare Siliconomas in an HIV Patient.

Siliconomas are rare conditions stemming from uses of silicone injections for soft tissue augmentation, most commonly in the breast and buttocks areas. Siliconomas are known to present with suspicious morphology that mimics cases of embolism or systemic metastasis as the silicone travels through blood and lymphatics. We present the case of a 45-year-old HIV-positive male who presented with siliconomas in the breast region, chest heaviness, shortness of breath, dyspnea, and a physical exam showing gynecomastia. The patient denied any surgeries or injections around his chest. Further imaging showed abnormal fat deposition in the chest and possible metastatic lymphadenopathy to axillary, supraclavicular, and mammillary lymph nodes. Although the complications arising from silicone injections are well documented, the pathogenesis remains unknown, leaving a narrow range of therapeutic options. Despite these shortcomings, diagnostic imaging tools have shown to be vital in the diagnosis and localization of suspected siliconomas.