R. De Vos

Immunoelectron microscopic localization of hepatic transferrin receptors in human liver with and without iron overload

SummaryThe expression of transferrin receptors (TfR’s) has been investigated in eight liver biopsy specimens (four from patients without demonstrable iron and four from patients with iron storage due to primary hemochromatosis (HC)) using immunoelectron microscopy to demonstrate TfR’s by the simultaneous application of two specific monoclonal antibodies (OKT9 and B3/25) to tissue chopper sections. In the four specimens without iron overload, hepatocytes, but not sinusoidal lining cells, stained positively and immunoreactivity was mainly localized in the cytoplasm. Positively stained cisternae of the endoplasmic reticulum indicated synthesis of the TfR. The presence of TfR’s on segments and coated invaginations of the sinusoidal membrane and in small, but otherwise unidentified vesicles in the cytoplasm is compatible with endo-/exocytotic transport and recycling of TfR’s as demonstrated by biochemical studies. Ocassional positively stained material in canalicular lumina together with positively stained canalicular microvilli and pericanalicular vesicles suggest that transcellular transport may be an additional pathway for TfR’s. In three biopsies showing severe iron overload due to HC, TfR immunoreactivity was completely absent. The remaining specimen showing HC, exhibited relatively mild iron overload and showed only a few positively stained hepatocytes. This supports the previously reported disappearance of hepatic TfR expression in HC when iron overload is severe.

Isolated condyloma acuminatum of the bladder in a patient with multiple sclerosis: etiological and pathological considerations.

We report a solitary condyloma acuminatum of the bladder without cutaneous, anogenital or urethral involvement in a patient with multiple sclerosis who had an indwelling suprapubic catheter. The lesion was treated by endoscopic resection.

Perinatal development of bilirubin UDP-glycosyltransferase activities in rat liver

Bilirubin UDP-glucuronyltransferase and UDP-xylosyltransferase activity could already be demonstrated in rat liver from day 19 of fetal life onwards (4 days before birth). Bilirubin-glucuronide was present in hepatocytes of 21-day-old fetal liver strongly suggesting that the enzyme detected in vitro was really active in vivo. This further supports the theory that secretion from the cell is also immature. The known deficiency of UDP-glucose dehydrogenase in fetal and neonatal rat liver could lead to decreased intracellular concentrations of UDP-glucuronic acid and possibly to increased concentrations of UDP-glucose. However, no glucosides were present in the fetal hepatocytes.

A case of Lelis syndrome with hystrix‐like ichthyosis

M.A.M. van Steensel,* V. Winnepenninckx, I.F. Nagtzaam, R. Janssens, R. De Vos, and P.M. Steijlen Department of Dermatology, University Hospital Maastricht, Maastricht, The Netherlands GROW Research School, University of Maastricht, Maastricht, The Netherlands Department of Pathology, University Hospital Maastricht, Maastricht, The Netherlands The Jeroen Bosch Hospital, ‘s Hertogenbosch, The Netherlands Department of Pathology, Catholic University of Leuven, Leuven, Belgium

delta-Storage pool disease: a pitfall in the forensic investigation of sudden anal blood loss in children: a case report.

We present the case of a 3.5-year-old boy with sudden anal blood loss at school. Sexual abuse was suspected, and, apart from anal fissures seen on sigmoidoscopy, no other clinical signs of any sort of disorder were present. As no medical explanation for the blood loss could be given, penetrating anal trauma was suggested. During follow-up consultations, there were complaints of occasional blood loss. Platelet aggregation tests and electron microscopy finally helped diagnose a δ-storage pool disease which is a rare haemostatic disorder involving the dense granules of the platelets. Although exclusion of well-known blood diseases through routine laboratory testing is a common practice in children with sudden blood loss, this case illustrates the value of more specialised investigation both from a diagnostic and forensic point of view.