Liver steatosis in hypobetalipoproteinemia. A case report.

A case of hypobetalipoproteinemia is described; a 16-year-old girl had been suffering for nearly 2 years from diffuse abdominal pain. The only clinical features were liver steatosis, slightly increased amino transferases and an incipient polyneuropathy. No sign of malabsorption or gastrointestinal disease was found. She had extremely low levels of cholesterol and triacylglycerol in her serum, slightly decreased serum phospholipids and normal HDL-cholesterol levels. Apolipoprotein B-100 was approx. 8% of normal, whereas B-48 was present at essentially normal levels. Electron microscopy of lipoprotein particles showed normal morphology of LDL. Examination of close relatives showed no abnormalities. Southern blots revealed no major deletions or rearrangements at the genomic level. Although rare, a- and hypobetalipoproteinemia should be considered as possible etiologies in patients with unexplained steatosis in the liver.

[Bladder rupture after minor trauma]. / Blaereruptur etter minimale traume.

Rupture of the urinary bladder is a rare injury most often encountered after severe trauma and in conjunction with injuries to other organ systems. It may occur, however, without concomitant injury and also after minimal trauma. This diagnosis must be suspected in a patient with abdominal pain who is unable to void or who presents hematuria. The diagnosis is made by means of a retrograde cystogram using 350-400 ml contrast medium and supplemented by a drainage film. Intraperitoneal ruptures should be treated surgically by closure in layers, and drainage. Patients with extraperitoneal ruptures can safely be treated with simple catheter drainage until the rupture has healed, usually within 10-20 days. We report three cases of bladder rupture after minimal trauma and describe the state of the art of diagnosis and treatment of these injuries.

Is the RPM cell line a useful model for the study of megakaryocyte development?

The differentiation of megakaryoblasts into megakaryocytes and their release of blood platelets are complex and poorly understood processes. As an aid to investigate this process several cell lines with megakaryocyte characteristics have been established. One of these cell lines is the rat promegakaryoblast-like (RPM) cell line established by Cicoria and Hempling and used by others to describe maturation processes in megakaryocytes. We have used this cell line to study the synthesis of platelet-specific marker proteins. Severe difficulties led us to perform control experiments to confirm earlier findings. We were unable to confirm several of the previous reports, and we conclude that this particular cell line should not be recommended for the study of megakaryoblast differentiation.

A monoclonal antibody to a megakaryoblast-like cell line detects a protein found in blood cells and in the epithelial cell lining of various rat tissues.

Megakaryoblasts of bone marrow differentiate into megakaryocytes that in turn are the source of blood platelets. We have raised monoclonal antibodies to a megakaryoblast-like cell line derived from rat bone marrow (RPM cells). One antibody (Mab 213) and the corresponding antigen has been characterized by Western blotting and immunohistochemistry. Biosynthetic labeling with [35S]methionine showed that this antigen is synthesized by the RPM cells. In Western blots the antibody recognized proteins of about 90 kDa and 160 kDa in Triton extracts of RPM cells, whereas it recognized proteins of about 160 kDa and 200 kDa in Triton extracts of rat platelets and one of about 200 kDa in Triton extracts of various rat tissues (kidney, lung, intestine, and heart). By immunohistochemistry, the antigen was localized to the apical part of the epithelium lining certain parts of kidney tubuli, bronchi and large intestine.

Separation and visualization of apolipoprotein B species by sodium dodecyl sulfate-agarose gel electrophoresis and immunoblotting.

A method for separation and visualization of the different apolipoprotein B species using 0.2% sodium dodecyl sulfate-1.5% agarose gel electrophoresis and immunoblotting is described. The method is capable of demonstrating the different forms of apolipoprotein B (apo B) in plasma volumes of 10-50 microliters without prior ultracentrifugation. After ultracentrifugation of samples, estimation of the ratio between apo B 48 and apo B 100 is possible by scanning of Coomassie-stained gels or immunoblots.