Linkage of Gitelman syndrome to the thiazide-sensitive sodium-chloride cotransporter gene with identification of mutations in Dutch families.

Gitelman syndrome is a mostly autosomal recessive disorder affecting the renal tubular function associated with hypokalemia and hypomagnesemia. Functional studies point to a defect in the distal renal tubule in the thiazide-sensitive, electroneutral sodium-chloride co-transporter (TSC). Based upon the localization of a 2.6 cDNA encoding the human TSC to chromosome 16q13, polymorphic markers spanning the region from 16p12 to 16q21 were tested for linkage to the Gitelman syndrome locus in three Dutch families with autosomal recessive inheritance of this disorder. Using two-point linkage analysis, a maximum LOD score (Zmax of 4.49 (at theta = 0.00) was found for the marker D16S408. One crucial recombination event places the Gitelman syndrome locus distal to D16S419 at 16q12-13. Subsequently we have tested our group of Gitelman patients for mutations in the human TSC gene. Two mutations were identified in three Gitelman families. Our study confirms that the human TSC gene is involved in Gitelman syndrome. Patients from three Gitelman families reveal two identical human TSC mutations, suggesting these families share a common ancestor.

Bronchopulmonary sequestration associated with an aneurysm of the aberrant artery.

We describe a patient with an intralobar bronchopulmonary sequestration of the right lower lobe associated with a true aneurysm of the aberrant artery. Both findings were suspected before operation. The patient was treated successfully by resection of the right lower lobe with the sequestered lung tissue and aneurysm.

The small envelope glycoprotein (GS) of equine arteritis virus folds into three distinct monomers and a disulfide-linked dimer.

The small membrane glycoprotein (GS) of equine arteritis virus (EAV) is a minor virion component but is abundantly expressed in EAV-infected cells. In this study, we have analyzed its membrane topology, folding, oligomerization, and intracellular transport. We show that GS is a class I integral membrane protein with one functional N-glycosylation site. Gel electrophoresis under nonreducing conditions revealed that GS occurs in EAV-infected cells in four monomeric conformations and as disulfide-linked homodimers. The slowest-migrating monomeric form corresponded to the fully reduced GS protein; the three faster-migrating monomeric species are probably generated by the formation of alternative intrachain disulfide bonds between the three luminal cysteines in the molecule. The GS monomers were selectively retained in the endoplasmic reticulum, as judged by their permanent susceptibility to endoglycosidase H, whereas the GS dimers were specifically incorporated into virus particles and became endoglycosidase H resistant and sialylated during passage through the Golgi apparatus.

Rupture of renal artery aneurysm during pregnancy.

A case of rupture of a renal artery aneurysm during pregnancy is described. Both patient and child survived despite a delayed diagnosis and treatment. Renal artery aneurysm is a rare disease but rupture is increased in pregnancy with a high mortality for mother and child.

[Hemobilia, a rare and difficult diagnosis]. / Hemobilie, een zeldzame, moeilijke diagnose.

Haemobilia, i.e. blood loss via the bile ducts, is a rare disorder, which may be caused by trauma, vascular disorders, gallstones, infection/inflammation, tumours and coagulation disorders. Haemobilia may cause grave morbidity and mortality. Important symptoms are: gastrointestinal bleeding, jaundice and colicky pains in the right upper abdominal quadrant. Gastroduodenoscopy, ultrasound, ERCP, CT-scan and MRI may be used to obtain additional information when haemobilia is suspected. Selective angiography may provide detailed information of the bleeding, but is less appropriate as an initial screening method. Haemobilia may be treated by selective embolisation of the involved artery or by operative treatment. Embolisation is the treatment of first choice in most situations. We present a case report of a patient with recurrent haemobilia caused by a ruptured aneurysm of a hepatic artery leaking intermittently into the bile ducts. Partly because of the rareness of this syndrome, the disorder was recognized with delay in our patient. After two embolisation attempts had failed, he was treated successfully by obliterative endoaneurysmorrhaphy.