The kynurenine pathway is essential for rhodoquinone biosynthesis in Caenorhabditis elegans.

A key metabolic adaptation of some species that face hypoxia as part of their life cycle involves an alternative electron transport chain in which rhodoquinone (RQ) is required for fumarate reduction and ATP production. RQ biosynthesis in bacteria and protists requires ubiquinone (Q) as a precursor. In contrast, Q is not a precursor for RQ biosynthesis in animals such as parasitic helminths, and most details of this pathway have remained elusive. Here, we used Caenorhabditis elegans as a model animal to elucidate key steps in RQ biosynthesis. Using RNAi and a series of C. elegans mutants, we found that arylamine metabolites from the kynurenine pathway are essential precursors for RQ biosynthesis de novo Deletion of kynu-1, encoding a kynureninase that converts l-kynurenine (KYN) to anthranilic acid (AA) and 3-hydroxykynurenine (3HKYN) to 3-hydroxyanthranilic acid (3HAA), completely abolished RQ biosynthesis but did not affect Q levels. Deletion of kmo-1, which encodes a kynurenine 3-monooxygenase that converts KYN to 3HKYN, drastically reduced RQ but not Q levels. Knockdown of the Q biosynthetic genes coq-5 and coq-6 affected both Q and RQ levels, indicating that both biosynthetic pathways share common enzymes. Our study reveals that two pathways for RQ biosynthesis have independently evolved. Unlike in bacteria, where amination is the last step in RQ biosynthesis, in worms the pathway begins with the arylamine precursor AA or 3HAA. Because RQ is absent in mammalian hosts of helminths, inhibition of RQ biosynthesis may have potential utility for targeting parasitic infections that cause important neglected tropical diseases.

Clinical Presentation of Usher Syndrome Type 1B (USH1B) in a 10-Month-Old: A Case Report.

Usher Syndrome (USH) is a genetically inherited condition characterized by congenital sensorineural hearing loss and progressive vision loss secondary to retinitis pigmentosa. Patients may also display vestibular areflexia and balance issues secondary to inner ear damage. Usher Syndrome is the most commonly diagnosed syndrome within the blind-deaf community, and it accounts for a significant portion of the hearing and visual deficit cases among patients younger than 65 years of age. Due to the reported prevalence of Usher Syndrome in the United States, it appears there is chronic underdiagnosis in clinical settings throughout the country. A possible explanation for this is the visual deficits of Usher syndrome do not appear until later in life and thus inappropriately lower the index of suspicion for this diagnosis in young children with hearing deficits. This case study highlights a healthy newborn who failed the universal newborn hearing screening (UNHS) bilaterally and a follow-up hearing screening in a pediatrician's office. Auditory brainstem response (ABR) later confirmed bilateral severe-to-profound sensorineural hearing loss. Upon genetic testing, an abnormality in the Unconventional Myosin VII-A (MYO7) gene was discovered and consistent with Usher syndrome Type 1B (USH1B). Usher Syndrome should be considered on the differential for patients with congenital hearing loss. Genetic counseling should be used if no other cause of sensorineural hearing loss is identified. Due to the progressive nature of this condition and the physical and developmental deficits that will transpire without treatment, a genetic panel for hearing loss should be prioritized to determine the presence of genetic mutations suggesting Usher syndrome.

The Diagnosis, Treatment, and Clinical Sequelae of Sjogren's Syndrome in a Pediatric Patient: A Case Report.

Sjogren's Syndrome is a chronic multisystem autoimmune condition where lymphocytes attack exocrine glands. Although this condition occurs in pediatric populations, it is often a missed diagnosis or diagnosis made after significant disease progression, frequently leading to extensive investment of time and resources. This case study follows a six-year-old African American female who, after an extensive medical course, was ultimately diagnosed with Sjogren's Syndrome. This case study intends to increase awareness of the potential abnormal presentations of this connective tissue disease in special populations, specifically school-aged pediatric patients. Even with the rarity of this condition in the pediatric population, physicians should keep Sjogren's Syndrome on their differential diagnosis when a patient presents with atypical or non-specific autoimmune-like symptoms. The presentation of children can be more severe than anticipated in an adult. A rapid, multi-disciplinary approach must be implemented to improve the prognosis of pediatric patients with Sjogren's Syndrome.

Implementation of Ultrasound in Preclinical Education at Osteopathic Medical Schools: A Scoping Review.

Ultrasound (US) is recognized as a practical and safe form of medical imaging that utilizes ultrasound waves to develop images for diagnostic and procedural purposes. The clinical use of US has dramatically increased over recent years, secondary to the ease of use, portability, and functionality of US. The success of point-of-care ultrasound implementation into residency curricula has further underscored the importance of US education and its potential for use earlier in medical instruction. Osteopathic medical education places a significant emphasis on anatomy, thus a scoping review of the literature regarding the use of US in osteopathic preclinical years is warranted. The goal of this scoping study is to assess the current literature regarding the implementation and benefit of US instruction in preclinical osteopathic medical curricula. Four resources were utilized for the review, including PubMed, Google Scholar, JOM (formerly JAOA), and AMED, each with contiguous criteria for applicable literature. The searches were performed before the end of January 2023. Inclusion criteria for researched literature focused on osteopathic preclinical utilization of US technologies. Articles were subsequently evaluated using thematic and contextual analysis. Of the 2,968 articles evaluated, 22 articles met the inclusion criteria. There were several themes associated with the implementation of US within osteopathic curricula, including positive student perceptions of the modality, improved learning outcomes, and adaptations of US instruction into anatomical sciences courses. There is a need for continued research regarding US implementation in preclinical osteopathic medical school education, including within anatomical sciences. A minority of osteopathic schools have published details regarding how US has been applied in their curriculum.