Differential diagnosis of chordoma, chondroid, and ependymal tumors as aided by anti-intermediate filament antibodies.

Six chordomas, nine chondrosarcomas, and three myxopapillary ependymomas of the filum terminale were evaluated immunohistochemically for the expression of intermediate filament proteins by the use of monospecific antibodies against intermediate filament proteins of keratin, vimentin, and glial fibrillary acidic protein (GFAP) type. All chordomas were positive for keratin but negative for GFAP, whereas chondrosarcomas and ependymomas were negative for keratin. Chondrosarcomas showed strong vimentin positivity, whereas ependymomas were positive for GFAP. Chordomas showed desmosomelike junctions by electron microscopy, whereas chondrosarcomas of different types showed no junctions or only primitive ones. By electron microscopy chordomas often showed prominent intermediate filaments also associated with desmosomes, and poorly differentiated chondrosarcomas also showed prominent intermediate filaments. Keratin positivity of chordomas suggests their epithelial nature, while vimentin positivity of chondrosarcomas is in line with their mesenchymal derivation. The results also show that antibodies against different intermediate filament proteins can be applied as diagnostic aids in making the distinction between chordomas, chondroid tumors, and ependymal tumors.     

Peritubular myoid cells of human and rat testis are smooth muscle cells that contain desmin-type intermediate filaments

We studied the cytoskeletal composition of human and rat testicular myoid cells by using immunofluorescence microscopy with polyclonal and monoclonal antibodies. In adult human and rat testis, the peritubular myoid cell layer was brightly positive for desmin, the muscle type of intermediate filament protein, and a faint reaction was also seen with antibodies to vimentin, the intermediate filament protein of fibroblasts and diverse other mesenchymal cells. The desmin-positive myoid cell layer could already be identified in newborn rat testis but was more compact in appearance 23 days after birth. Both squash preparations and cultured cells from adult rat seminiferous tubules revealed distinct cell populations positive for desmin. The adult myoid cells of both species also showed a strong reaction with antibodies to myosin and p230, a nonerythroid avian alpha-spectrin analogue. The immunostaining results could be confirmed by the western blotting technique: Experiments with isolated seminiferous tubules showed a specific reaction with a 55,000-dalton and a 58,000-dalton polypeptide when desmin and vimentin antibodies were used, respectively. The present results show that the peritubular myoid cells are genuine smooth muscle cells with desmin-type intermediate filament cytoskeleton and suggest that these cells can be identified by this feature before their ultrastructural maturation.     

Cellular origin and differentiation of renal carcinomas. A fluorescence microscopic study with kidney-specific antibodies, antiintermediate filament antibodies, and lectins

Frozen sections of human renal carcinomas were studied in indirect immunofluorescence using antibodies against intermediate filaments of cytokeratin, desmin and vimentin type, and against proximal tubular brush border and distal tubular Tamm-Horsfall glycoprotein antigens, as well as with fluorochrome-labeled lectins in an attempt to study the origin and stage of differentiation of renal carcinomas. Eighty per cent of the renal carcinomas expressed the brush border antigens, whereas the Tamm-Horsfall glycoprotein could not be found. Antibodies against epidermal cytokeratins reacted only with collecting ducts in normal kidney, whereas antibodies against cytokeratins of Madin-Darby canine kidney epithelial cell line also reacted with glomerular and tubular epithelium. In 93% of the carcinomas tumor cells showed reactivity with both types of antikeratin antibodies. Vimentin, the cytoskeletal protein of mesenchymal cells, was present in the carcinoma cells of 53% of the tumors, although it was not present in normal tubular epithelium. Moreover, vimentin was expressed together with cytokeratin in the carcinoma cells in 57% of the keratin-positive samples as judged by double immunostaining, whereas the muscle type of intermediate filament protein, desmin, was not seen in the malignant cells. Binding sites for Lotus tetragonolobus agglutinin and soybean agglutinin, normally present in the cells of proximal tubules, were lacking or only faintly detectable in the neoplastic cells. Dolichos biflorus agglutinin, normally present in collecting ducts, was not detected in the tumors. The results show that most renal carcinomas express cytokeratin antigens as a sign of their epithelial origin and also show characteristics of proximal tubular cells. On the other hand, the results indicate that lectin-binding sites typical for normal differentiated tubular cells are profoundly modified in renal carcinomas. Ulex europaeus agglutinin did not bind to the malignant cells but decorated the endothelial cells of the tumors.     

Infant botulism acquired from household dust presenting as sudden infant death syndrome

Clostridium botulinum type B was detected by multiplex PCR in the intestinal contents of a suddenly deceased 11-week-old infant and in vacuum cleaner dust from the patient's household. C. botulinum was also isolated from the deceased infant's intestinal contents and from the household dust. The genetic similarity of the two isolates was demonstrated by pulsed-field gel electrophoresis and randomly amplified polymorphic DNA analysis, thereby confirming that dust may act as a vehicle for infant botulism that results in sudden death.     

Ulex europaeus I lectin as a marker for tumors derived from endothelial cells

Some skin and soft tumors, which generally are assumed to be derived from endothelial cells or blood vessels, were characterized with fluorochrome-labeled Ulex europaeus I agglutinin (UEA I), recently shown to bind specifically to endothelial cells in various normal human tissues. The staining pattern was compared with that obtained with immunostaining using antibodies against factor-VIII-related antigen (FVIII-RAG), a known marker for endothelial cells. The results showed that UEA-I is a specific and a more sensitive marker for the endothelial cells in benign vascular lesions as compared with anti-FVIII-RAG. UEA-I also stained many neoplastic cells of endothelial sarcomas, which generally were negative for FVIII-RAG. Melanomas, anaplastic carcinomas, and other types of sarcomas were negative for both UEA-I and FVIII-RAG. The results suggest that UEA-I lectin is a specific and sensitive adjunct tool in demonstrating endothelial cells and endothelial derivation of human tumors.     

Cytomegalovirus in urine: detection of viral DNA by sandwich hybridization.

A cytomegalovirus (CMV)-specific sandwich hybridization test was constructed by using two adjacent BamHI DNA fragments of CMV DNA as reagents. The fragments were cloned into two different vectors. One of the recombinants was attached to the filter, and the other was the labeled probe. When present in the sample, CMV DNA mediated labeling of the filter by hybridizing to both the filter-bound DNA and the probe. The sandwich hybridization test was applied for the detection of CMV DNA from urine. DNA was released from virus by 2% Sarkosyl, concentrated by 2-butanol extraction and isopropanol precipitation, denatured, and finally subjected to the sandwich hybridization test. As a result, 70 to 90% of the original viral DNA could be recovered and demonstrated by the quantitative hybridization reaction. Urine could be stored at room temperature in Sarkosyl for at least 2 days without affecting the detectability of CMV. The clinical applicability of the test was evaluated by studying urine samples from four infants excreting CMV. Sandwich hybridization demonstrated the presence of CMV DNA in all of the specimens. These contained originally 10(5) to 10(8) CMV DNA molecules per ml.     

Distribution of renal integrin receptors and their ligands in congenital nephrotic syndrome of the finnish type

The aim of this study was to examine the distribution of 1 and v integrins (Ints) and some of their ligands in the kidneys of patients with congenital nephrotic syndrome of the Finnish type (CNF) and in controls using indirect immunofluorescence with monoclonal antibodies. The mesangial reactivity of Int 1 and Int 1 subunits was more variable and an increased glomerular reactivity with Int 3 and Int-6 antibodies was found in CNF kidneys than in controls. Int 2 subunit was either completely missing from or found in significantly lesser amounts in CNF kidney glomeruli. The immunoreactivity for Int v was more variable, fainter and also more granular in CNF samples than in control kidneys. The glomerular reactivity for Int 5 was more diffuse and weaker, and in sclerotic Bowman's capsules more intense in CNF kidneys than in controls. Immunoreactivity for Int 6 was restricted and was comparable in extent in CNF and control kidneys. Of the extracellular matrix components studied, the expression of EDAFn, EDBFn, OncFn, Ln 2 chain, Ln 1 chain and tenascin was increased. This is also seen in several glomerular diseases with inflammation and sclerosis. Immunoreactivity for vitronectin was decreased. Several differences were found in the intensity or location of the immunostaining for the 1 and v Ints and their ligands in CNF kidneys compared with controls, which have not been found in any other proteinuric disease. Disturbed Int expression pattern in CNF may specifically reflect the disturbance of glomerular function caused by the primary defect in this disease.     

Maternal Vitamin C and Iron Intake during Pregnancy and the Risk of Islet Autoimmunity and Type 1 Diabetes in Children: A Birth Cohort Study

Our aim was to study the associations between maternal vitamin C and iron intake during pregnancy and the offspring’s risk of developing islet autoimmunity and type 1 diabetes. The study was a part of the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) prospective birth cohort including children genetically at risk of type 1 diabetes born between 1997–2004. The diets of 4879 mothers in late pregnancy were assessed with a validated food frequency questionnaire. The outcomes were islet autoimmunity and type 1 diabetes. Cox proportional hazards regression analysis adjusted for energy, family history of diabetes, human leukocyte antigen (HLA) genotype and sex was used for statistical analyses. Total intake of vitamin C or iron from food and supplements was not associated with the risk of islet autoimmunity (vitamin C: HR 0.91: 95% CI (0.80, 1.03), iron: 0.98 (0.87, 1.10)) or type 1 diabetes (vitamin C: 1.01 (0.87, 1.17), iron: 0.92 (0.78, 1.08)), neither was the use of vitamin C or iron supplements associated with the outcomes. In conclusion, no association was found between maternal vitamin C or iron intake during pregnancy and the risk of islet autoimmunity or type 1 diabetes in the offspring.     

Clinical and genetic features of variegate porphyria in a Chinese patient

Acute porphyria is rare in orientals. We describe a Chinese woman with recurrent generalised tonic-clonic seizures and abdominal pain. Genomic DNA studies identified a heterozygous base substitution from guanine to adenine at nucleotide position 503, resulting in substitution of arginine by histidine at position 168 of the protein (R168H). This genetic abnormality is similar to the mutation reported in Caucasians with variegate porphyria. To the best of our knowledge, this is the first report in the English literature a Chinese patient with variegate porphyria with an identifiable mutation. A brief review of porphyria is presented.     

Bladder pheochromocytoma encountered on sonography

Pheochromocytomas of the bladder are rare neoplasms, constituting <0.06% of all vesical tumours. Common presenting features of this tumour include episodes of sweating, hypertension, haematuria and postmicturition syncope. We describe a case of bladder pheochromocytoma in a 66‐year‐old man whose only symptom of macroscopic haematuria was initially assessed with ultrasonography. Clinical presentation highlights the need for a high index of suspicion during sonographic evaluation of bladder neoplasms because such tumours might present without symptoms of adrenergic excess.