Diagnostic role of an immunoassay-detected polymorphism of factor IX for potential carriers of hemophilia B

In hemophilia B, assays based on a monoclonal antifactor IX specific for the Thr-148 variant of an exonic polymorphism have diagnosed carriers in selected families by either establishing linkage or by indicating the presence or absence of a given normal factor IX. The sensitivity of the immunoassays for detecting heterozygous women was explored by comparing results from immunoassays with solid-phase polyclonal v the monoclonal antifactor IXs. Factor IX with the normal Ala-148 variant gave a flat dilution curve, qualitatively distinct from factor IX with the Thr-148 variant in the monoclonal assay. The two were indistinguishable in the polyclonal assay. Mixtures of equal amounts of the two types gave an intermediate result, about half as reactive in the monoclonal as compared with the polyclonal assay system. Whereas mixtures with 10% Ala-148 and 90% Thr-148 factor IXs could not readily be distinguished from Thr-148 factor IX plasma, as little as 1% of the Thr-148 protein was detected in Ala-148 factor IX plasma. The frequency of the Ala-148 variant varied in individuals with different ethnic backgrounds; it was found in 29% of white, 12% of black, and none of Asian blood donors' factor IX genes in Seattle. Only 4% of samples from South African black men were nonreactive (ie, Ala- 148). The Thr/Ala-148 dimorphism is in strong linkage disequilibrium with Taql restriction fragment length polymorphisms (RFLPs). Three recombinations were noted in normal white genes and one in a normal black factor IX gene (less than 2% of those examined). In 34 white families with at least one woman being a possible carrier, genetically, the immunoassay results were informative in 18. RFLP analyses were informative in eight of the 15 families tested. In five families each, assignment of carrier status was made to a woman by only DNA or only immunoassay results, whereas the other approach was noninformative. The immunoassays provide a rapid, inexpensive screening test and complement DNA analysis in white women who are potential carriers of hemophilia B.     

Increased production of vascular endothelial growth factor in peritoneal macrophages of cirrhotic patients with spontaneous bacterial peritonitis

Spontaneous bacterial peritonitis (SBP) is a common complication of cirrhotic patients with ascites that usually results in renal failure and death despite the efficacy of the current antibiotic therapy. The pathogenesis of these phenomena is poorly known but it has been related to the production of vasoactive cell mediators locally acting on the splanchnic vasculature. Because previous studies showed that peritoneal macrophages of cirrhotic patients may produce high quantities of vascular endothelial growth factor (VEGF), a powerful vessel permeabilizing agent, when stimulated by cytokines and bacterial lipopolysaccharide, the present study was aimed to seek whether peritoneal macrophages of SBP patients are induced to produce increased amounts of VEGF. Our results indicate that the production rate and the messenger RNA (mRNA) and protein expression of this substance are increased in macrophages of patients with SBP in comparison with those of noninfected cirrhotic patients. This characteristic feature is absent in circulating monocytes of these patients. Moreover, enhanced endothelial cell proliferation induced by conditioned medium of macrophages isolated from the ascites of patients with SBP is abolished by anti-VEGF antibody, and peritoneal tissue of cirrhotic patients expresses both VEGF receptors, Flt-1 and KDR. These results, therefore, are consistent with the concept that locally released macrophage-derived VEGF may result in increased vascular permeability and plasma leakage in the peritoneal vessels of cirrhotic patients with SBP.     

Clinicopathological and molecular features of myeloid sarcoma as initial presentation of therapy-related myeloid neoplasms: a single institution experience

Therapy-related myeloid neoplasms (t-MN) have a common origin in prior cytotoxic therapy and/or radiation. These neoplasms include therapy-related acute myeloid leukemia, myelodysplastic syndrome (t-MDS), and myelodysplastic/myeloproliferative neoplasms (t-MDS/MPN). Myeloid sarcoma (MS), on the other hand, is a rare disease manifesting as an extramedullary collection of immature cells of myeloid lineage. Rarer still is therapy-related MS (t-MS), which has not been adequately studied due to its rarity and its lack of recognition as a unique entity among other t-MN. Here, we report what is to our knowledge the first case series of t-MS, with the aim of investigating and establishing salient clinicopathological and molecular features of this entity.     

Anticandidal activity of plants used for the treatment of vaginitis in Guatemala and clinical trial of a Solanum nigrescens preparation

An ethnobotanical survey detected 71 plants used for the treatment of vaginitis by traditional healers, health promoters and midwives. Extracts prepared by maceration of plants in 50% methanol were impregnated on absorbent paper disks and placed over plates with Candida albicans. Eight (11.3%) of these plants showed some degree of inhibition. Solanum nigrescens was chosen for further studies. A cream containing a 50% ethanolic maceration was applied daily to the vagina of female guinea pigs for 15 days and observed for another 15 days. Since no inflammatory changes were observed, this preparation was used for clinical trials. Two groups of 50 non-pregnant women with confirmed C. albicans vaginitis were treated for 15 days, one group with intra-vaginal suppositories containing S. nigrescens maceration and the other with nystatin suppositories. By statistical analysis it was demonstrated that both groups behaved in a similar beneficial way suggesting that this plant may be effective for the treatment of candidal vaginitis.     

Primary and staged transposition arteriovenous fistulas

BACKGROUND: The use of catheters or prosthetic grafts for vascular access has significantly higher mortality and morbidity risks, in addition to higher costs, than arteriovenous fistulas (AVF). Many patients have a difficult access extremity due to complex medical illnesses, previous vascular access procedures, intravenous catheters, diabetes, vascular disease, female sex, age, and other complicating factors. Transposition AVFs (AVF-T) have been used for these individuals to avoid catheters and grafts. We report our experience with primary and staged basilic vein AVF-Ts and staged brachial vein AVF-Ts. METHODS: From our database of consecutive vascular access operations, we reviewed patients from May 2003 to September 2006 for all upper extremity AVF-Ts. A primary AVF-T was used when the basilic vein was continuous with a minimum diameter of 4 mm and of adequate length. When the basilic vein was 2.5 to 4 mm, the procedure was staged. The proximal radial artery was used for inflow, if possible. When the basilic vein was not suitable, a radial vein or brachial vein anastomosis was performed as the first stage of a planned brachial vein AVF-T. The second stage operations of staged AVF-Ts were generally done 4 to 6 weeks after the primary AVF construction. All patients were evaluated with preoperative ultrasound imaging by the operating surgeon. RESULTS: From a database of 412 consecutive vascular access patients, 78 upper extremity transposition procedures were identified. Of these, 57 patients (73.1%) were women, 44 (56.4%) were diabetic, and 46 (59.0%) had previous access surgery. Fifty-eight operations were staged procedures. The basilic vein was used in 68 AVF-T, the brachial vein in six, and cephalic vein in four. The anastomosis was based on the proximal radial artery in 60 patients. Mean follow-up was 18 months (range, 3-48 months). Primary patency, primary assisted patency, and cumulative patency were 45.7%, 93.5%, and 96.0% at 12 months and 27.6%, 86.5%, and 88.9% at 24 months, respectively. No prosthetic grafts were used in the study period. CONCLUSION: Both primary and staged AVF-T procedures were successfully used in patients with difficult access extremities. AVF-Ts were durable, although many required an interventional procedure for maturation or maintenance. Cumulative (secondary) patency was 96.0% at 12 months and 88.9% at 24 months. The absence of an adequate basilic vein does not preclude the use of a staged AVF-T because the brachial vein offers a suitable alternative.     

Transfusion-transmitted malaria: case report of asymptomatic donor harboring Plasmodium malariae

Malaria in Brazil is endemic in the Amazon region, but autochthonous cases with low parasitaemia occur in the Atlantic Forest area of the country. According to Brazilian legislation no test is mandatory for blood donors from non-endemic areas. However if they have traveled to malaria transmission regions they are deferred for six months before they can donate. This report describes a transfusion-transmitted malaria case in Sao Paulo, Brazil, where one recipient received infected blood and developed the disease. He lived in Sao Paulo and had no previous transfusion or trips to endemic areas, including those of low endemicity, such as Atlantic Forest. Thick blood smears confirmed Plasmodium malariae. All donors lived in Sao Paulo and one of them (Donor 045-0) showed positive hemoscopy and PCR. This asymptomatic donor had traveled to Juquia, in the Atlantic Forest area of S ao Paulo State, where sporadic cases of autochthonous malaria are described. DNA assay revealed P. malariae in the donor's (Donor 045-0) blood. Serum archives of the recipient and of all blood donors were analyzed by ELISA using both P. vivax and P. falciparum antigens, and IFAT with P. malariae. Donor 045-0's serum was P. malariae IFAT positive and the P. vivax ELISA was reactive. In addition, two out of 44 donors' archive sera were also P. vivax ELISA reactive. All sera were P. falciparum ELISA negative. This case suggests the need of reviewing donor selection criteria and deferral strategies to prevent possible cases of transfusion-transmitted malaria.