Characterization of human platelet glycoprotein antigens giving rise to individual immunoprecipitates in crossed-immunoelectrophoresis

Washed human platelets were labeled with 125I by the lactoperoxidase- catalyzed method and solubilized in 1% Triton X-100. The soluble proteins were analyzed by crossed-immunoelectrophoresis in 1% agarose, employing a rabbit antibody raised against whole human platelets. Analysis of autoradiograms developed from dried agarose gels led to the establishment of a normal reference pattern that was consistent for platelets obtained from more than 50 normal individuals. Six platelet membrane glycoprotein antigens contained in four distinguishable precipitates were identified. Each identification was based on direct sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of 125I-antigens contained in individually excised precipitates. These platelet antigens include major membrane glycoproteins previously designated la, lb, lla, llb, llla, and lllb. Glycoproteins llb and llla were shown to be contained in a single immunoprecipitate, while glycoproteins la and lla were routinely detected in a single different immunoprecipitate. Analysis of soluble proteins from platelets of five patients with Glanzmann's thrombasthenia demonstrated either a complete absence or a marked reduction of only one radiolabeled precipitate, that containing membrane glycoproteins llb and llla. Platelet samples from two patients with Bernard-Soulier syndrome were devoid of a different precipitate, that containing membrane glycoprotein lb.     

Insulin glargine-based therapy improves glycemic control in patients with type 2 diabetes sub-optimally controlled on premixed insulin therapies

The AT.LANTUS trial recently demonstrated the efficacy and safety of insulin glargine initiation and maintenance using two different treatment algorithms in poorly controlled type 2 diabetes mellitus (T2DM). This sub-analysis investigated glycemic control and safety in 686 patients switching from premixed insulin (premix) with or without (+/-OADs) to once-daily glargine (+/-OADs/prandial insulin). A 24-week, multinational (n=59), multicenter (n=611), randomized study comparing two algorithms (Algorithm 1: clinic-driven titration; Algorithm 2: patient-driven titration) in four glargine+/-OADs treatment groups: alone, once- (OD), twice- (BD) or >twice- (>BD) daily prandial insulin. After switching to the glargine regimen, HbA(1c) levels significantly improved in the overall group (9.0+/-1.3 to 8.0+/-1.2%; p<0.001) and in all subgroups; fasting blood glucose levels also improved in all subgroups (overall: 167.1+/-50.0 to 106.9+/-27.2 mg/dL [9.3+/-2.8 to 5.9+/-1.5 mmol/L]; p<0.001). The incidence of severe hypoglycemia was also low in all four subgroups (< or =1.7%). Patients with T2DM switching from premix+/-OADs to glargine+/-OADs had significant reductions in glycemic control with a low incidence of severe hypoglycemia. The addition of prandial (OD, BD or >BD) insulin was associated with further improvements in glycemic control. These data provide support for the stepwise introduction of prandial insulin to a more physiologic basal-bolus regimen, which is under investigation.     

Van Buchem disease: Clinical,biochemical, and densitometric features of patients and disease carriers

Van Buchem disease (VBD) is a rare bone sclerosing dysplasia caused by the lack of a regulatory element of the SOST gene, which encodes for sclerostin, an osteocyte‐derived negative regulator of bone formation. We studied the demographic, clinical, biochemical, and densitometric features of 15 patients with VBD (12 adults and 3 children) and 28 related carriers of the gene mutation. The most common clinical findings in patients were facial palsy (100%) and various degrees of hearing impairment (93%); raised intracranial pressure had been documented in 20%. The clinical course of the disease appeared to stabilize in adulthood, with the majority of patients reporting no progression of symptoms or development of complications with time. Carriers of the disease had none of the clinical features or complications of the disease. Sclerostin could be detected in the serum in all but 1 VBD patients (mean 8.0 pg/mL; 95% confidence interval [CI], 4.9–11.0 pg/mL), and were lower than those of carriers (mean 28.7 pg/mL; 95% CI, 24.5–32.9 pg/mL; p < 0.001) and healthy controls (mean 40.0 pg/mL; 95% CI, 34.5–41.0 pg/mL; p < 0.). Serum procollagen type 1 amino‐terminal propeptide (P1NP) levels were also significantly higher in adult patients (mean 96.0; 95% CI, 54.6–137.4 ng/mL versus mean 47.8; 95% CI, 39.4–56.2 ng/mL, p = 0.003 in carriers and mean 37.8; 95% CI, 34.5–41.0 ng/mL, p = 0.028 in healthy controls) and declined with age. Bone mineral density (BMD) was markedly increased in all patients (mean Z‐score 8.7 ± 2.1 and 9.5 ± 1.9 at the femoral neck and spine, respectively); BMD of carriers was significantly lower than that of patients but varied widely (mean Z‐scores 0.9 ± 1.0 and 1.3 ± 1.5 at the femoral neck and spine, respectively). Serum sclerostin levels were inversely correlated with serum P1NP levels (r = –0.39, p = 0.018) and BMD values (femoral neck r = –0.69, p < 0.001; lumbar spine r = –0.78, p < 0.001). Our results show that there is a gene‐dose effect of the VBD deletion on circulating sclerostin and provide further in vivo evidence of the role of sclerostin in bone formation in humans. The small amounts of sclerostin produced by patients with VBD may explain their milder phenotype compared to that of patients with sclerosteosis, in whom serum sclerostin is undetectable. © 2013 American Society for Bone and Mineral Research.     

Imaging and intervention of retroperitoneal fibrosis

Retroperitoneal fibrosis is a rare condition characterized by the development of fibrous plaques in the retroperitoneal space. The fibrous plaques characteristically arise distal to the bifurcation of the abdominal aorta and progress to encase the iliac vessels distally and are defined by the associated encasement of one or both ureters. Imaging plays an important role in not only establishing the diagnosis, but also in monitoring disease progression. Historically, the radiological diagnosis was made predominantly by intravenous urography and retrograde pyelography. More recently, advances in cross‐sectional imaging with ultrasound and contrast‐enhanced CT have allowed for a more precise diagnosis as well as helping to accurately define the extent of the disease. At our institution, we have found ultra‐fast MRI to also play a useful role in establishing the diagnosis. In particular, magnetic resonance urography using HASTE (half Fourier‐acquired single shot turbo spin‐echo) sequences allow a safe alternative to intravenous urography, particularly in patients with poor renal function. The purpose of this article is to describe the role of the various imaging methods available to the radiologist and to emphasize the important role that the interventional radiologist now plays, not only in obtaining tissue for diagnosis, but also in providing treatment of the disease by percutaneous nephrostomy drainage and subsequent stent placement in select cases.     

Ultrasonographic and computed tomographic findings in Madelung disease in two Chinese patients.

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Protection from lethal malaria in transgenic mice expressing sickle hemoglobin

Previous studies from our laboratories have shown that transgenic mice expressing high levels of beta S globin are well-protected from Plasmodium chabaudi adami and partially protected against P berghei (Shear et al, Blood 81:222, 1993). We have now infected transgenic mice expressing low (39%), intermediate (57%), and high (75%) levels of beta S with the virulent strain of P yoelii (17XL) that appears to cause cerebral malaria. We find that the level of protection in these three groups of mice correlates positively with the level of beta S chain expression in the mice. Seven of nine mice expressing the high level of beta S recovered from infection, as did 7 of 9 mice expressing the intermediate level of beta S. Control mice and mice expressing the lower level of beta S all succumbed to infection. In mice expressing high and intermediate levels of beta S, parasites were found almost exclusively in reticulocytes during recovery, suggesting that mature red blood cells expressing beta S are more resistant than reticulocytes. These studies confirm epidemiologic data and offer insight into the mechanism of protection of sickle trait individuals against falciparum malaria.     

Symposium: reproduction in baboons. The baboon oviduct: characteristics of an oestradiol-dependent oviduct-specific glycoprotein

The baboon oviductal epithelium differentiates into a tall columnarepithelium consisting of ciliated and secretory cells duringthe follicular phase of the menstrual cycle in response to risingoestradiol levels. The apical tips of these secretory cellsare filled with membrane-bound secretory granules. During theluteal phase when progesterone levels are elevated, the epitheliumregresses and deciliation occurs. Analysis of secretory proteinsobtained from explant culture media by SDS-PAGE followed byfluorography or Western Blots has revealed that the baboon oviductsynthesizes and secretes a high molecular weight glycoproteinduring the follicular phase of the cycle. Immunocytochemistrydemonstrated that the oviductal glycoprotein is localized tothe secretory granules of epithelial secretory cells, is oviductspecific, and that following secretion the oviductal glycoproteinbinds to the zona pellucida and periviteline space of ovulatedoocytes and embryos within the oviduct. Similar proteins havebeen characterized in other mammalian species. cDNA data showthat the complete coding sequence is 2228 bp for a protein of623 amino acids. A Genbank search showed that baboon oviductalglycoprotein has high homology to other oviductal glycoproteinsequences at both the nucleotide and amino acid levels. Studiesconducted to date probing the biological function of oviductalglycoprotein indicate that this protein plays a role in prefertilizationreproductive events (sperm capacitation; sperm-zona binding;zona penetration). Additional experiments are needed to reveala specific function and mechanism for this molecule.     

Clinical significance of CD34 expression in childhood acute lymphoblastic leukemia

The CD34 antigen was detected on > or = 10% of the blast cells in 235 (70%) of 335 cases of newly diagnosed childhood acute lymphoblastic leukemia (ALL) treated in two consecutive chemotherapy trials. By immunophenotype, the distribution of positive cases favored early pre-B ALL (83%; n = 180) followed by pre-B ALL (61%; n = 89) and then T-cell ALL (46%; n = 61) (P < .001). Among the B-lineage cases, CD34 expression was significantly associated with favorable presenting features: age 1 to 10 years, white race, absence of central nervous system (CNS) leukemia, low serum lactate dehydrogenase level, CD10 expression, and leukemic cell hyperdiploidy (> 50 chromosomes or DNA index > or = 1.16). Event-free survival was clearly superior for patients with CD34+ leukemia (P = .01), with an estimated 83% +/- 6% (SE) of the cohort remaining free of adverse events at 5 years post diagnosis, as compared to 63% +/- 10% of the group without this feature. Multivariate analysis showed that the prognostic influence of the antigen was independent of age, leukocyte count, and other well- recognized factors, suggesting that it would add discriminatory power to current systems of risk assignment. Findings in T-cell ALL were the reverse: CD34 expression showed positive correlations with initial CNS leukemia and CD10 negativity but not with any good-risk presenting characteristics. Log-rank analysis indicated no adverse effect on treatment outcome by CD34 antigen expression, although additional patients with need to be studied to obtain a definitive answer. The opposed clinical associations of CD34 expression in B- and T-lineage ALL may reflect fundamental biologic differences between these leukemia species.