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We have created a human chromosomal map of the location of known and candidate genes involved in primary lymphedema (PLE). This should facilitate further discovery and provide a basis for understanding microdeletions which cause lymphedema.

SOX18 mutations in humans are associated with both recessive and dominant hypotrichosis-lymphedema-telangiectasia syndrome (HLTS). We report two families with affected children carrying a SOX18 mutation: a living patient and his stillborn brother from Canada and a Belgian patient. The two living patients were diagnosed with HLTS and DNA analysis for the SOX18 gene showed that both had the identical heterozygous C A transversion, resulting in a pre-mature truncation of the protein, lacking the transactivation domain. Both living patients developed renal failure with severe hypertension in childhood for which both underwent renal transplantation. To our best knowledge this is the first report of renal failure associated with heterozygous mutations in the SOX18 gene. We conclude that this specific mutation results in a new, autosomal dominant condition and propose the acronym HLT-renal defect syndrome for HLTRS.

Superantigens (SAgs) are potent microbial toxins that bind simultaneously to T cell receptors (TCRs) and class II major histocompatibility complex molecules, resulting in the activation and expansion of large T cell subsets and the onset of numerous human diseases. Within the bacterial SAg family, streptococcal pyrogenic exotoxin I (SpeI) has been classified as belonging to the group V SAg subclass, which are characterized by a unique, relatively conserved approximately 15 amino acid extension (amino acid residues 154 to 170 in SpeI; herein referred to as the alpha3-beta8 loop), absent in SAg groups I through IV. Here, we report the crystal structure of SpeI at 1.56 A resolution. Although the alpha3-beta8 loop in SpeI is several residues shorter than that of another group V SAg, staphylococcal enterotoxin serotype I, the C-terminal portions of these loops, which are located adjacent to the putative TCR binding site, are structurally similar. Mutagenesis and subsequent functional analysis of SpeI indicates that TCR beta-chains are likely engaged in a similar general orientation as other characterized SAgs. We show, however, that the alpha3-beta8 loop length, and the presence of key glycine residues, are necessary for optimal activation of T cells. Based on Vbeta-skewing analysis of human T cells activated with SpeI and structural models, we propose that the alpha3-beta8 loop is positioned to form productive intermolecular contacts with the TCR beta-chain, likely in framework region 3, and that these contacts are required for optimal TCR recognition by SpeI, and likely all other group V SAgs.

Vascular anomalies are localized defects of the vasculature, and usually affect a limited number of vessels in a restricted area of the body. They are subdivided into vascular malformations and vascular tumours. Most are sporadic, but Mendelian inheritance is observed in some families. By genetic analysis, several causative genes have been identified during the last 10 years. This has shed light into the pathophysiological pathways involved. Interestingly, in most cases, the primary defect seems to affect the characteristics of endothelial cells. Only mutations in the glomulin gene, responsible for hereditary glomuvenous malformations, are thought to directly affect vascular smooth-muscle cells.

A 55-year-old woman with a 1-year history of nonsmall cell lung cancer underwent planar bone imaging with nonvisualization of the right kidney. The kidneys were in their usual location as seen on a bone scan taken 13 months earlier. Subsequent computed tomography identified inferior and anterior displacement of the right kidney by a large right subpulmonic effusion and a pleural-parenchymal abnormality that displaced the diaphragm and liver inferiorly

Frozen-thawed, deglycerolized RBCs can be substituted for saline-washed RBCs for transfusion of patients with paroxysmal nocturnal hemoglobinuria (PNH). The effect of transfusion is to decrease bone marrow production of RBCS, which results in a decreased percentage of complement-sensitive erythrocytes. In the presence of small numbers of complement-sensitive erythrocytes, major vascular surgery can be performed without hemolytic problems. This study suggests that the percentage of complement-sensitive RBCs, as well as the complement sensitivity of these cells, influence the severity of hemolysis in persons with PNH.

Summary. Endogenous carbon monoxide (CO) production rates and total body haemoglobin content were determined simultaneously in blood and gas phase in 15 individuals. At 24% oxygen (O2) concentration in the closed rebreathing system, a correlation was obtained which revealed that a 1 μmole rise in CO in the gas phase of the system was the result of 48.94± 5.3 (SE) μmoles of CO rise in the body. Three individuals had heat-damaged red cells reinjected intravenously to determine if the recovery rate of the subsequently produced CO was proportionate in both the gas phase and blood phase. Changes in blood CO concentration were not consistently detected by gas phase analysis. Prediction of CO production rates utilizing gas phase data alone did not reflect accurately CO production rates determined from blood carboxyhaemoglobin rises.

A 17-year-old patient is discussed who had the tachycardia-bradycardia syndrome following closure of a sinus venosus atrial septal defect. Cardiac standstill up to 7.2 seconds long occurred, but placement of a permanent demand pacemaker was avoided. This unique case demonstrates that permanent pacemaker may not always be necessary in the tachycardia-bradycardia syndrome, especially when it occurs in a young postsurgical patient.