Arthritis-associated changes in flow cytometric characteristics of cultured synovial fibroblasts

Synovial fibroblasts cultured from patients with rheumatoid or reactive arthritis and from controls were studied by flow cytometry, spectroscopy, and electron microscopy. Analysis of 29 cell lines revealed consistent differences between arthritic and normal fibroblasts. Cells cultured from inflamed synovial tissue exhibited higher autofluorescence than did control fibroblasts, and displayed exceptional light scatter properties in flow cytometry, indicating changes in cytoplasmic structures. Electron microscopic examination of the fibroblasts from arthritic synovial tissue revealed large numbers of round, swollen, laminated, mitochondrion-like bodies, which were not observed in the control fibroblasts. The changes observed by flow cytometry (light scatter and autofluorescence) coincided with the presence of the mitochondrion-like organelles. The strong autofluorescence observed in the arthritic fibroblasts resembled the fluorescence spectrum of mitochondrial flavoproteins. These data suggest that persistent metabolic and structural changes have occurred in the mitochondria of synovial fibroblasts and inflammatory synovial tissue. The usefulness of flow cytometry in identifying such cells is described.     

Infantile onset encephalomyopathy,retinopathy, optic atrophy,and mitochondrial DNA depletion associated with a novel pathogenic DHX16 variant

We studied a patient with mitochondrial DNA depletion in skeletal muscle and a multiorgan phenotype, including fatal encephalomyopathy, retinopathy, optic atrophy, and sensorineural hearing loss. Instead of pathogenic variants in the mitochondrial maintenance genes, we identified previously unpublished variant in DHX16 gene, a de novo heterozygous c.1360C>T (p. Arg454Trp). Variants in DHX16 encoding for DEAH-box RNA helicase have previously been reported only in five patients with a phenotype called as neuromuscular oculoauditory syndrome including developmental delay, neuromuscular symptoms, and ocular or auditory defects with or without seizures. We performed functional studies on patient-derived fibroblasts and skeletal muscle revealing, that the DHX16 expression was decreased. Clinical features together with functional data suggest, that our patient's disease is associated with a novel pathogenic DHX16 variant, and mtDNA depletion could be a secondary manifestation of the disease.     

Fistulisation of an iliac pseudoaneurysm into the appendix. Presentation of a case and a review of the literature

A case of ilioappendiceal fistula is presented. The patient had previously been operated on for a ruptured aneurysm of the common iliac artery. 21 years later he developed occult gastrointestinal bleeding without signs of infection. Colonoscopy revealed bloody faeces and an isotope scan haemorrhage in the ascending colon. Laparotomy and right hemicolectomy was performed without identifying the fistula. The head of the appendix was left attached to the scarred peritoneal wall. As the bleeding continued, a second laparotomy was performed revealing an iliac pseudoaneurysm with fistulisation into the head of the appendix. Vascular reconstruction was attempted, but the patient succumbed to massive bleeding on the operating table.     

Expression of B-L and Bu-1 antigens in chickens bursectomized at 60 h of incubation

Differences in expression between B-L (chicken class II major histocompatibility complex antigen) and Bu-1 B cell antigens were found in normal animals by using monoclonal antibodies and flow cytometric immunofluorescence analysis. Fluorescence intensity profile was used in assaying cell surface density of antigen molecules. The density of B-L antigen on the cell surface is apparently low in immature and high in mature cells, whereas the density of Bu-1 antigen does not vary in cells at different maturational stages. The existence of B-L+ and Bu-1+ cells in chickens bursectomized at 60 h of embryonic development (Bx) is demonstrated, indicating that neither B-L or Bu-1 antigen is exclusively specific for cells differentiated in the bursa. The densities of B-L and Bu-1 molecules on lymphoid cells in Bx chickens are similar to those of controls. However, the number of B-L+ and Bu-1+ cells was decreased in Bx chickens. We conclude that the extrabursal site where Bx B cells mature has an ability similar to that of the bursa to induce and enhance the expression of B-L and Bu-1 antigens. However, only few B cells proliferate and/or are released into the circulation. Further, the extrabursal site unequivocally lacks the most important function of the bursa, the creation and expansion of antibody diversity.     

The Glu318Gly mutation of the presenilin-1 gene does not necessarily cause Alzheimer's disease

In early-onset familial Alzheimer's disease pathogenic mutations have been found in the amyloid precur sor protein (APP) gene and in the presenilin (PS)-1 and PS-2 genes. We screened for mutations in these genes in 20 patients with familial AD from the Finnish population. In addition, we sampled 41 sporadic AD patients and 59 controls to test for mutations identified in our familial AD cases. We detected an A-to-G transition in the PS-1 gene, resulting in a glutamic acid (G1u)-to- glycine (Gly) substitution at codon 318 in 2 familial and 2 sporadic AD patients. The Glu318Gly mutation has previously been reported to cause AD. We also found the Glu318Gly mutation in 4 healthy aged controls (range, 74–87 years). We thus conclude that the mutation is most likely a rare polymorphism not related to AD.     

SNCA multiplication is not a common cause of Parkinson disease or dementia with Lewy bodies

The authors recently have shown that triplication of the alpha-synuclein gene (SNCA) can cause Parkinson disease (PD) and diffuse Lewy body disease within the same kindred. The authors assessed 101 familial PD probands, 325 sporadic PD cases, 65 patients with dementia with Lewy bodies, and 366 neurologically normal control subjects for SNCA multiplication. The authors did not identify any subjects with multiplication of SNCA and conclude this mutation is a rare cause of disease.     

CHEK2 variant I157T may be associated with increased breast cancer risk

Cell cycle checkpoint kinase 2 (CHEK2) is a transducer of cellular responses to DNA damage. The CHEK2 1100delC has previously been shown to be a low-penetrance breast cancer susceptibility allele. We have evaluated the role of another CHEK2 variant, I157T in the FHA domain of the gene, for association with breast cancer. I157T was found at a significantly higher frequency in the population-based series of breast cancer patients (77/1035, 7.4%, odds ratio [OR] = 1.43, 95% confidence interval [CI] = 1.06-1.95, p = 0.021) than among population controls (100/1885, 5.3%). The frequency in the familial breast cancer patients was not elevated (28/507, 5.5%, OR = 1.04, 95% CI = 0.68-1.61). The I157T protein, that undermines cellular responses to ionizing radiation and shows deficiency in substrate recognition in vivo, was expressed at normal level in tumor tissues as well as in cultured cells. The I157T protein was stable and it dimerized with the wild-type CHEK2 co-expressed in human cells. These functional properties of the I157T protein suggest that this variant may have negative effect on the pool of normal CHEK2 protein in heterozygous carrier cells by formation of heterodimers with wild-type CHEK2. The I157T variant may be associated with breast cancer risk, but the risk is lower than for 1100delC.     

Corticosteroids in patients with a high risk of fat embolism syndrome.

The effects of methylprednisolone on the clinical fat embolism syndrome were studied in a series of 60 patients who had at least two fractures of the pelvis, femur and tibia and who did not have any other important injuries. This series was dichotomized at random, and 29 patients were given 10 milligrams per kilogram of methylprednisolone three times, once upon admission and, then, at eight and 16 hours post-traumatically. Thirty-one patients served as controls. Fat embolism syndrome was defined as a combination of hypoxemia, bilateral "snow storm" infiltrations of the lungs, petechial rash, mental disturbances, pyrexia, anemia and thrombocytopenia. Varying degrees of the syndrome were observed in two patients given methylprednisolone and in 15 patients in the control group. Methylprednisolone reduced all individual signs. There were no fatalities in this series of fracturers. No complications were observed from the use of methylprednisolone. Methylprednisolone in an early pharmacologic dosage is effective in fulminant instances of fat embolism that occur in spite of adequate respiratory care and the proper treatment of fractures.     

Uracil-DNA glycosylase activity in chronic lymphoproliferative disorders

The activity of uracil-DNA glycosylase, a repair enzyme for the excision of uracil from DNA, was studied in patients with chronic lymphoproliferative disorders and with malignant plasma cell dyscrasias. The biochemical assay was performed on mononuclear cells, isolated by density gradient centrifugation from peripheral blood, from bone marrow or from both. The activity of the uracil-DNA glycosylase of peripheral blood cells in 8/8 cases of myeloma and in 3/3 cases of Waldenstr?m's macroglobulinemia was in the same range as in 22 non-hematological control patients, i.e. 2.4-25.1 U/mg of protein. Higher activities were found in 9/12 cases of chronic lymphocytic leukemia (CLL), in 2/4 cases of hairy cell leukemia (HCL), in 2/2 cases of chronic T-cell lymphocytosis and in the only case of small cell lymphocytic lymphoma. Follow-up of some CLL and HCL patients revealed that uracil-DNA glycosylase activity was fairly stable during the course of the disease. We conclude that malignant cells in chronic lymphoproliferative disorders are characterized by a normal or even increased capability to repair DNA, as exemplified by uracil-DNA glycosylase in this study.