Altered synthesis of interferon-γ and expression of interferon-γ receptor by peripheral blood mononuclear cells from patients with IgA nephropathy and non-IgA proliferative glomerulonephritis

Previously we reported disease-specific interaction between interferon- (IFN-) and interleukin-4 (IL-4) in patients with IgA nephropathy (IgAN), suggesting the existence of unusual T cell behavior in this disease. In the present study, we investigated characteristic synthesis of interferon- (IFN-) and expression of IFN- receptor (IFN-R) in the peripheral blood mononuclear cells (PBMC) from patients with IgAN and other chronic proliferative glomerulonephritis (PGN). Heparinized peripheral blood samples were obtained from 38 patients with chronic mesangial proliferative glomerulonephritis (CGN; including 24 with IgA nephropathy) and 20 healthy controls. PBMC were isolated by gradient centrifugation and fragments were cultured in Iscove's modified Dulbecco's medium (IMDM) supplemented with 10% fetal calf serum (FCS) for 72 hr. IFN- concentrations in supernatants were evaluated by the enzyme-linked immunosorbent assay (ELISA). Other parts of PBMC pellets were reacted with anti-human IFN-R monoclonal antibody and FITC-labeled anti-mouse second antibody for analysis of IFN-R expression on these cells by FACScan. The remaining PBMC were fractionated into CD4⁺ T cells, CD8⁺ T cells, B cells, NK, cells and macrophages using the MACS cell sorting system. The isolated cells were evaluated for IFN- or IFN-R mRNA expression by the semiquantitative RT-PCR method.In vitro IFN- synthesis was enhanced in patients with CGN, and NK cells were revealed to be responsible for such enhancement. On the other hand, the expression of IFN-R on macrophages was suppressed in CGN patients. These results suggest that impairment of regulation of the IFN- system might be involved in the development of CGN.     

Persistent infection of SARS coronavirus in colonic cells in vitro

Severe acute respiratory syndrome coronavirus (SARS-CoV) can produce gastrointestinal symptoms. The intestinal tract is the only extrapulmonary site where viable viruses have been detected. This study examined seven established human intestinal cell lines, DLD-1, HCT-116, HT-29, LoVo, LS-180, SW-480 and SW-620, for their permissiveness to SARS-CoV infection. The results showed that only LoVo cells were permissive to SARS-CoV infection as evident by positive findings from indirect immunofluorescence staining for intracellular viral antigens, in situ hybridization for intracellular viral RNA, and electron microscopy for intracellular viral particles. In contrast to Vero cells, SARS-CoV did not produce cytopathic effects on LoVo cells. However, LoVo cells were found to be highly permissive for productive infection with a high viral titre (>3 x 10(7) viral copies/ml) produced in culture supernatant following a few days of incubation. SARS-CoV established a stable persistent chronic infection that could be maintained after multiple passages. Being a cell line of human origin, LoVo cells could be a useful in vitro model for studying the biology and persistent infection of SARS-CoV. Our results on the expression of angiotensin-converting enzyme 2 (ACE2), a recently identified cellular receptor for SARS-CoV, in these cell lines indicated that it might not be the sole determinant for cells to be susceptible to SARS-CoV infection.     

Glomus tumor beneath the plica synovialis in the knee: a case report

Glomus tumors are rare benign tumors distinguished clinically by their small size and ability to cause extreme pain. These lesions are usually found beneath the fingernails. Atypical locations of the tumor are difficult to diagnose, especially when the lesion is situated in a deep anatomic structure. We describe a 33-year-old man with glomus tumor beneath the plica synovialis in the knee. He had experienced right knee pain for 10 years which increased with movements of the knee. There was a point of tenderness on palpation at the lateral aspect of the knee. CT scan with arthrography showed a small mass on the lateral femoral condyle in the joint space. It was seen retrospectively in MRI. Arthroscopy demonstrated the soft tissue mass beneath the plica synovialis. We made a separate incision and removed it completely. An immediate disappearance of the pain was observed after surgery. Histology was the glomus tumor of the vascular type. The tumor seemed to be stimulated by the plica synovitis or the lateral joint capsule and it caused pain on motion similar to meniscal tear. There has been no recurrence for 3 years after surgery.     

Epstein-Barr virus-associated smooth muscle tumor in patients with acquired immunodeficiency syndrome.

Epstein-Barr virus (EBV)-associated smooth muscle tumor (SMT) is a recognized but uncommon disease that is found to occur in patients with immunocompromised conditions such as acquired immunodeficiency syndrome (AIDS). These tumors may be multifocal and located at unusual sites, such as the brain and liver. This report describes the case of 2 AIDS patients with EBV-associated SMT and highlights the features and outcome of this rare but potentially important tumor in human immunodeficiency virus management.     

Schwannoma arising from the sublingual gland

Sublingual gland tumors, especially mesenchymal tumors, are extremely rare. We describe the first reported case of schwannoma arising from the sublingual gland with details of the histopathologic and immunohistochemical features. A 70-year-old woman developed a painless swelling on the floor of the mouth. The excised material was sublingual gland tissue with an ovoid, grayish-yellow solid tumorous mass at the cut surface. The tumor was composed of proliferated spindle-shaped tumor cells exhibiting palisading patterns. In the center of the tumor, a small salivary gland component was recognized. Immunohistochemically, the tumor cells were strongly positive for S-100 protein but negative for neurofilament protein. The Ki-67 labeling index was 4.58. The clear presence of a remnant sublingual gland lobule in the present tumor provided convincing evidence that it was a schwannoma arising from the sublingual gland and thus the first of its type to be reported.     

Novel mutations in PHKA2 gene in glycogen storage disease type IX patients from Hong Kong, China

The diagnosis of glycogen storage disease (GSD) type IX is often complicated by the complexity of the phosphorylase kinase enzyme (PHK), and molecular analysis is the preferred way to provide definitive diagnosis. Here we reported two novel mutations found in two GSD type IX patients with different residual enzyme activities from Hong Kong, China using genetic analysis and, provided the molecular interpretation of the deficient PHK activity. These two newly described mutations would be useful for the study of future GSD patients.     

Heterozygous COL9A3 variants cause severe peripheral vitreoretinal degeneration and retinal detachment

The COL9A3 gene encodes one of the three alpha chains of Type IX collagen, with heterozygous variants reported to cause multiple epiphyseal dysplasia, and suggested as contributory in some cases of sensorineural hearing loss. Patients with homozygous variants have midface hypoplasia, myopia, sensorineural hearing loss, epiphyseal changes and carry a diagnosis of Stickler syndrome. Variants in COL9A3 have not previously been reported to cause vitreoretinal degeneration and/or retinal detachments. This report describes two families with autosomal dominant inheritance and predominant features of peripheral vitreoretinal lattice degeneration and retinal detachment. Genomic sequencing revealed a heterozygous splice variant in COL9A3 [{"type":"entrez-nucleotide","attrs":{"text":"NG_016353.1","term_id":"283945463"}}NG_016353.1({"type":"entrez-nucleotide","attrs":{"text":"NM_001853.4","term_id":"1432073434"}}NM_001853.4):c.1107 + 1G>C, NC_000020.10({"type":"entrez-nucleotide","attrs":{"text":"NM_001853.4","term_id":"1432073434"}}NM_001853.4):c.1107 + 1G>C, LRG1253t1] in Family 1, and a heterozygous missense variant [{"type":"entrez-nucleotide","attrs":{"text":"NG_016353.1","term_id":"283945463"}}NG_016353.1({"type":"entrez-nucleotide","attrs":{"text":"NM_001853.4","term_id":"1432073434"}}NM_001853.4):c.388G>A p.(Gly130Ser)] in Family 2, each segregating with disease. cDNA studies of the splice variant demonstrated an in-frame deletion in the COL2 domain, and the missense variant occurred in the COL3 domain, both indicating the critical role of Type IX collagen in the vitreous base of the eye.Subject terms: Genetic testing, Medical genetics, Medical genomics     

93G, a novel sporadic strain of hepatitis E virus in South China isolated by cell culture

The nucleotide sequence of Hepatitis E virus (HEV) serous isolates (G-9 and G-20) from Guangzhou, South China, which has been reported previously, are divergent significantly from those of other reported HEV isolates. In order to investigate more extensively the Guangzhou isolate, the 93G strain was isolated from the faecal sample of the same individual as G-9 by A549 cell culture and identified immunologically and by molecular biological techniques. The results showed that strain 93G could be propagated in an A549 cell line causing cytopathic effects. The viral particles were aggregated by a specific antibody to HEV Chinese Xinjiang strain (87A) observed using immunoelectron microscopy and were similar morphologically to HEV from other sources. In this study, an indirect fluorescent antibody assay was first developed to examine HEV antigen in the infected cells, by immunofluorescence in the cytoplasm and on the surface membrane of the cells. The 58-kDa and 82-kDa native structural proteins of HEV were also identified in this study by Western blotting. The 93G genome showed high homology (93%) with G-9 previously reported but was also as divergent from the Burmese, Mexican, Chinese Xinjiang isolates and the recently reported US-1 isolate, as was G-9. The data presented indicate that 93G propagated in A549 cells, together with its related serum isolate G-9, represents another HEV strain circulating in China and is responsible for some sporadic hepatitis E infections.