Hepatic Hilar Lymph Node Reactivity at Kasai Portoenterostomy for Biliary Atresia: Correlations With Age, Outcome, and Histology of Proximal Biliary Remnant

We hypothesized that if infection is the proximate cause of congenital biliary atresia, an appropriate response to antigen would occur in lymph nodes contiguous with the biliary remnant. We compared the number of follicular germinal centers (GC) in 79 surgically excised hilar lymph nodes (LN) and 27 incidentally discovered cystic duct LNs in 84 subjects at the time of hepatic portoenterostomy (HPE) for biliary atresia (BA) to autopsy controls from the pancreaticobiliary region of non-septic infants >3 months old at death. All 27 control LN lacked GC, a sign in infants of a primary response to antigenic stimulation. GC were found in 53% of 106 LN in 56 of 84 subjects. Visible surgically excised LN contiguous with the most proximal biliary remnants had 1 or more well-formed reactive GC in only 26/51 subjects. Presence of GC and number of GC/LN was unrelated to age at onset of jaundice or to active fibroplasia in the biliary remnant but was related to older age at HPE. Absent GC in visible and incidentally removed cystic duct LNs predicted survival with the native liver at 2 and 3 years after HPE, P = .03, but significance was lost at longer intervals. The uncommon inflammatory lesions occasionally found in remnants could be secondary either to bile-induced injury or secondary infection established as obstruction evolves. The absence of consistent evidence of antigenic stimulation in LN contiguous with the biliary remnant supports existence of at least 1 major alternative to infection in the etiology of biliary atresia

Megalencephalic Leukoencephalopathy with Subcortical Cysts: A Third Confirmed Case with Literature Review

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) causes early-onset, slowly progressive central nervous system white matter disease, macrocephaly, and later cognitive and motor decline. We describe brain structure in a patient with MLC and proven MLC1 mutations. A male, normal at birth, had macrocephaly at 6 months followed by developmental delay. Magnetic resonance imaging showed extensive signal abnormality in cerebral white matter and subcortical progressive cystic changes in the bilateral temporal and right frontal areas. Biopsy of frontal gyrus at age 15 months showed normal gray matter. The subcortical white matter was pale due to prominent fine uniform 2- to 4-mu-thick vacuoles with a few interspersed myelinated axons and rare microglia. The vacuoles had a single-, double-, or, rarely, triple-unit membrane (resembling myelin) and contained occasional organelles but no intermediate filaments. Both normal myelinated and thinly myelinated axons were observed. The outer and occasionally the inner layers of myelin surrounding intact axons formed blebs that may represent a source for vacuoles. Genetic analysis identified 2 heterozygous mutations of intron 3 (c.322-1 G>A) and intron 7 (c.597+1G>A), the 1st leading to deletion of amino acids 60 to 89 and the 2nd to deletion of amino acids 194 to 199. Fine uniform vacuolation of white matter with wide separation of myelinated axons is the hallmark of MLC in early childhoo

Surgically induced osteoarthritis in the rat results in the development of both osteoarthritis-like joint pain and secondary hyperalgesia

SummaryObjectiveIn the present study, we sought to develop/characterize the pain profile of a rat model of surgically induced osteoarthritis (OA).MethodsOA was surgically induced in male Lewis rats (200–225g) by transection of the medial collateral ligament and medial meniscus of the femoro-tibial joint. In order to characterize the pain profile, animals were assessed for a change in hind paw weight distribution (HPWD), development of mechanical allodynia, and the presence of thermal and mechanical hyperalgesia. Rofecoxib and gabapentin were examined for their ability to decrease change in weight distribution and tactile allodynia.ResultsTransection of the medial collateral ligament and medial meniscus of male Lewis rats resulted in rapid (<3 days) changes in hind paw weight bearing and the development of tactile allodynia (secondary hyperalgesia). There was, however, no appreciable effect on thermal hyperalgesia or mechanical hyperalgesia. Treatment with a single dose of rofecoxib (10mg/kg, PO, day 21 post surgery) or gabapentin (100mg/kg, PO, day 21 post surgery) significantly attenuated the change in HPWD, however, only gabapentin significantly decreased tactile allodynia.ConclusionThe rat medial meniscal tear (MMT) model mimics both nociceptive and neuropathic OA pain and is responsive to both a selective cylooxygenase-2 (COX-2) inhibitor commonly utilized for OA pain (rofecoxib) and a widely prescribed drug for neuropathic pain (gabapentin). The rat MMT model may therefore represent a predictive tool for the development of pharmacologic interventions for the treatment of the symptoms associated with OA