A Rare Case of Benign Recurrent Intrahepatic Cholestasis Initially Diagnosed in Middle-age.

Background: Repeated episodes of jaundice and pruritus are common in a group of autosomal recessive liver diseases known as benign recurrent intrahepatic cholestasis. Benign recurrent intrahepatic cholestasis (BRIC) is divided into two types, type 1 and type 2, and is caused by mutations in the ATP8B1 and ABCB11 genes. Here, we report a rare case of BRIC type 2 mutation. Case presentation: A 45-year-old Chinese man had three frequent episodes of jaundice marked by extensive excoriation and severe pruritis, although he had no prior history of jaundice. Laboratory investigations showed no evidence of liver damage caused by viral, autoimmune, or acquired metabolic etiologies. The CT scan revealed an enlarged gallbladder with numerous punctate high-density shadows, while no wall thickening was observed. Endoscopic ultrasonography showed no evidence of dilation of the intrahepatic and extrahepatic bile duct, as well as the absence of gallstone. Diagnostic evaluation: Immunohistochemical examinations of liver biopsy samples showed cytokeratin-7 positive hepatocytes, suggesting chronic intrahepatic cholestasis. The reticulin fiberstaining demonstrated that the portions of the hepatic plate in the center of the lobule were asymmetrically organized,and somewhat enlarged, with collapsed areas indicating intralobular inflammation. Moreover, there were areas of collapse that indicated the presence of intralobular inflammation. Whole exome sequencing revealed mutations in the ABCB11 gene; c.3084A>G, p.A1028A homozygous mutation (chr2-169789016), and c.2594C>T, p.A865V heterozygous mutation (chr2-169801131). Based on these findings, the final diagnosis of the patient was metabolism-related jaundice. Treatment: Apart from receiving tapering dosage of prednisone to lower bilirubin levels, the patient received no extra care. Conclusion: The comprehensive diagnosis of a middle-aged male patient with BRIC-2, which involved extensive radiological, hematological, and genetic investigations, informed a tailored tapering prednisone regimen, highlighting the importance of personalized medicine in managing atypical presentations of this rare cholestatic disorder.

C. elegans touch receptor neurons direct mechanosensory complex organization via repurposing conserved basal lamina proteins.

The sense of touch is conferred by the conjoint function of somatosensory neurons and skin cells. These cells meet across a gap filled by a basal lamina, an ancient structure found in metazoans. Using Caenorhabditis elegans, we investigate the composition and ultrastructure of the extracellular matrix at the epidermis and touch receptor neuron (TRN) interface. We show that membrane-matrix complexes containing laminin, nidogen, and the MEC-4 mechano-electrical transduction channel reside at this interface and are central to proper touch sensation. Interestingly, the dimensions and spacing of these complexes correspond with the discontinuous beam-like extracellular matrix structures observed in serial-section transmission electron micrographs. These complexes fail to coalesce in touch-insensitive extracellular matrix mutants and in dissociated neurons. Loss of nidogen reduces the density of mechanoreceptor complexes and the amplitude of the touch-evoked currents they carry. Thus, neuron-epithelium cell interfaces are instrumental in mechanosensory complex assembly and function. Unlike the basal lamina ensheathing the pharynx and body wall muscle, nidogen recruitment to the puncta along TRNs is not dependent upon laminin binding. MEC-4, but not laminin or nidogen, is destabilized by point mutations in the C-terminal Kunitz domain of the extracellular matrix component, MEC-1. These findings imply that somatosensory neurons secrete proteins that actively repurpose the basal lamina to generate special-purpose mechanosensory complexes responsible for vibrotactile sensing.

A tonically active master neuron modulates mutually exclusive motor states at two timescales.

Continuity of behaviors requires animals to make smooth transitions between mutually exclusive behavioral states. Neural principles that govern these transitions are not well understood. Caenorhabditis elegans spontaneously switch between two opposite motor states, forward and backward movement, a phenomenon thought to reflect the reciprocal inhibition between interneurons AVB and AVA. Here, we report that spontaneous locomotion and their corresponding motor circuits are not separately controlled. AVA and AVB are neither functionally equivalent nor strictly reciprocally inhibitory. AVA, but not AVB, maintains a depolarized membrane potential. While AVA phasically inhibits the forward promoting interneuron AVB at a fast timescale, it maintains a tonic, extrasynaptic excitation on AVB over the longer timescale. We propose that AVA, with tonic and phasic activity of opposite polarities on different timescales, acts as a master neuron to break the symmetry between the underlying forward and backward motor circuits. This master neuron model offers a parsimonious solution for sustained locomotion consisted of mutually exclusive motor states.

Adiposity in Chinese people with type 1 diabetes.

Adiposity, synonymous with obesity, is prevalent among both children and adults with type 1 diabetes in China. Recent literature underscored the patho-physiological and socioeconomic factors associated with adiposity, and consistently highlighted its impact on cardiovascular, kidney, and metabolic diseases among Chinese individuals with type 1 diabetes. Addressing and managing adiposity in individuals with type 1 diabetes are complicated and entail comprehensive approaches including lifestyle modifications, cognitive-behavioral therapy, insulin dose titration, and other diabetes treatment medications. The condition calls for coordination among policymakers, researchers, clinicians, and patients.

A leak K+ channel TWK-40 sustains the rhythmic motor program.

Leak potassium (K+) currents, conducted by two-pore domain K+ (K2P) channels, are critical for the stabilization of the membrane potential. The effect of K2P channels on motor rhythm remains enigmatic. We show here that the K2P TWK-40 contributes to the rhythmic defecation motor program (DMP) in Caenorhabditis elegans. Disrupting TWK-40 suppresses the expulsion defects of nlp-40 and aex-2 mutants. By contrast, a gain-of-function (gf) mutant of twk-40 significantly reduces the expulsion frequency per DMP cycle. In situ whole-cell patch clamping demonstrates that TWK-40 forms an outward current that hyperpolarize the resting membrane potential of dorsorectal ganglion ventral process B (DVB), an excitatory GABAergic motor neuron that activates expulsion muscle contraction. In addition, TWK-40 substantially contributes to the rhythmic activity of DVB. Specifically, DVB Ca2+ oscillations exhibit obvious defects in loss-of-function (lf) mutant of twk-40. Expression of TWK-40(gf) in DVB recapitulates the expulsion deficiency of the twk-40(gf) mutant, and inhibits DVB Ca2+ oscillations in both wild-type and twk-40(lf) animals. Moreover, DVB innervated enteric muscles also exhibit rhythmic Ca2+ defects in twk-40 mutants. In summary, these findings establish TWK-40 as a crucial neuronal stabilizer of DMP, linking leak K2P channels with rhythmic motor activity.

Systemic immune-inflammation index and all-cause and cause-specific mortality in sarcopenia: a study from National Health and Nutrition Examination Survey 1999-2018.

Background: Sarcopenia, common in the elderly, often linked to chronic diseases, correlates with inflammation.The association between SII and mortality in sarcopenia patients is underexplored, this study investigates this relationship in a U.S. adult cohort. Methods: We analyzed 1999-2018 NHANES data, focusing on 2,974 adults with sarcopenia. Mortality outcomes were determined by linking to National Death Index (NDI) records up to December 31, 2019. Using a weighted sampling design, participants were grouped into three groups by the Systemic Immune-Inflammation Index (SII). We used Cox regression models, adjusting for demographic and clinical variables, to explore SII's association with all-cause and cause-specific mortality in sarcopenia, performing sensitivity analyses for robustness. Results: Over a median follow-up of 9.2 years, 829 deaths occurred. Kaplan-Meier analysis showed significant survival differences across SII groups. The highest SII group showed higher hazard ratios (HRs) for all-cause and cause-specific mortality in both crude and adjusted models. The highest SII group had a higher HR for all-cause(1.57, 1.25-1.98), cardiovascular(1.61, 1.00-2.58), cancer(2.13, 1.32-3.44), and respiratory disease mortality(3.21, 1.66-6.19) in fully adjusted models. Subgroup analyses revealed SII's association with all-cause mortality across various demographics, including age, gender, and presence of diabetes or cardiovascular disease. Sensitivity analyses, excluding participants with cardiovascular diseases, those who died within two years of follow-up, or those under 45 years of age, largely reflected these results, with the highest SII group consistently demonstrating higher HRs for all types of mortality in both unadjusted and adjusted models. Conclusion: Our study is the first to demonstrate a significant relationship between SII and increased mortality risks in a sarcopenia population.