No abstract

The newly proposed 15- and 24-loci mycobacterial interspersed repetitive unit (MIRU)-variable-number tandem repeat (VNTR) typing method was evaluated for its ability to differentiate 181 Mycobacterium tuberculosis Beijing family strains. Compared with the original 12-loci MIRU-VNTR typing method, the 15-loci system dramatically improved the discriminatory power for Beijing strains; however, large clusters that could be further differentiated by IS6110 restriction fragment length polymorphism (RFLP) were still obtained. The clonal stability and allelic diversity of a total of 31 VNTR loci were evaluated. VNTRs 3232, 3820, and 4120 were identified as the effective hypervariable VNTR set for the second-line typing of clustered strains following the 15-loci based scheme. Consequently, the discriminatory power of the new scheme (18 loci) equaled that of IS6110 RFLP.

We used 909 strains to compare the population structures of the Mycobacterium tuberculosis Beijing family between different birth-year cohorts in Japan. The results revealed that the spread of a modern sublineage that has high transmissibility is currently increasing, while the spread of an ancient sublineage, STK, has significantly decreased in younger generations.

FAP may shift to systemic WT TTR amyloid formation after LT, which seems to be similar to the process in SSA. The truncation of TTR in amyloid deposits may depend on some genetic or environmental factors other than undergoing LT.

Meningeal melanocytoma is a benign melanocytic tumor that originates most frequently from the melanocytes in the posterior fossa or along the spinal cord. This tumor generally occurs as an extraaxial mass that compresses adjacent neural structures to produce various neurological signs. The authors describe an unusual case in which a patient with a meningeal melanocytoma located at the thoracic spinal cord presented with superficial siderosis of the central nervous system (CNS). Extensive neuroradiological studies identified the presence of a spinal cord tumor, and postsurgical histological examination revealed the meningeal melanocytoma as a bleeding source. After surgery, lumbar puncture demonstrated normalization of the patient's cerebrospinal fluid; however, no neurological improvement occurred. The neurological deficits seem irreversible. Meningeal melanocytoma is biologically benign and can be cured by complete surgical resection; therefore, this tumor should be included in the differential diagnosis of pigmented lesions of the CNS. The authors reviewed 14 cases of well-documented meningeal melanocytoma in the literature and discuss the clinical, radiological, and pathological features of the present case to emphasize the importance of early diagnosis and identification of the source of bleeding in patients with superficial siderosis.