Increased factor VIII coagulant activity levels in male carriers of the factor V R2 polymorphism.

A common factor V gene haplotype, the FVR2 haplotype (FVHR2), has been associated with a reduced cofactor activity in activated protein C-mediated activated factor VIII inactivation. Our aim was to investigate the role of FVHR2 as a possible determinant of factor VIII levels in a population study. A total of 516 individuals (401 men, 115 women; mean age 58.4 +/- 10.8 years) were enrolled within the frame of a regional cardiovascular survey, characterized for factor VIII coagulant activity (FVIII:c) and factor V coagulant activity (FV:c) levels, and genotyped for factor V polymorphisms. In men without signs of overt inflammation, FVHR2 carriers had higher levels of FVIII:c than noncarriers (154 IU/dl, 95% confidence interval = 143-166 versus 142 IU/dl, 95% confidence interval = 138-147; P = 0.045) and were more represented in individuals with high (> or = 150 IU/dl) FVIII:c levels (21.2 versus 10.8%; odds ratio = 2.27, 95% confidence interval = 1.17-4.39 after adjustment for age, blood group and high-sensitivity C-reactive protein levels). In conclusion, this clinical report suggests the common FVHR2 as a possible independent determinant of FVIII:c levels. The report concomitantly addresses the relationship between factor V and factor VIII levels and supports the hypothesis of a mild prothrombotic role of FVHR2 by means of increased factor VIII levels.     

Influence of the centrifuge time of primary plasma tubes on routine coagulation testing.

Preparation of blood specimens is a major bottleneck in the laboratory throughput. Reliable strategies for reducing the time required for specimen processing without affecting quality should be acknowledged, especially for laboratories performing stat analyses. The present investigation was planned to establish a minimal suitable centrifuge time for primary samples collected for routine coagulation testing. Five sequential primary vacuum tubes containing 0.109 mol/l buffered trisodium citrate were collected from 10 volunteers and were immediately centrifuged on a conventional centrifuge at 1500 x g, at room temperature for 1, 2, 5, 10 and 15 min, respectively. Hematological and routine coagulation testing, including prothrombin time, activated partial thromboplastin time and fibrinogen, were performed. The centrifugation time was inversely associated with residual blood cell elements in plasma, especially platelets. Statistically significant variations from the reference 15-min centrifuge specimens were observed for fibrinogen in samples centrifuged for 5 min at most and for the activated partial thromboplastin time in samples centrifuged for 2 min at most. Meaningful biases related to the desirable bias were observed for fibrinogen in samples centrifuged for 2 min at most, and for the activated partial thromboplastin time in samples centrifuged for 1 min at most. According to our experimental conditions, a 5-10 min centrifuge time at 1500 x g may be suitable for primary tubes collected for routine coagulation testing.     

Triterpenoid saponins, new metalloprotease snake venom inhibitors isolated from Pentaclethra macroloba.

We report here the antiproteolytic and antihemorrhagic properties of triterpenoid saponin inhibitors, named macrolobin-A and B, from Pentaclethra macroloba, against Bothrops snake venoms. The inhibitors were able to neutralize the hemorrhagic, fibrin(ogen)olytic, and proteolytic activities of class P-I and P-III metalloproteases isolated from B. neuwiedi and B. jararacussu venoms. Clotting and fibrinogenolytic activities induced by snake venoms and isolated thrombin-like enzymes were partially inhibited. Furthermore, the potential use of these inhibitors to complement antivenom therapy as an alternative treatment and/or used as molecular models for development of new therapeutical agents in the treatment of snake bite envenomations needs to be evaluated in future studies.     

Dermoscopic Evolution of a Congenital Combined Nevus in Childhood

Background. A combined nevus most commonly consists of a blue nevus in combination with a Clark or Spitz nevus. Dermoscopically, combined nevus can mimic melanoma owing to the presence of dermoscopic features common to both types of lesions. Benign clinical and dermoscopic changes can occur in nevi over time, especially in children and young adults.
Objective. To describe the dermoscopic evolution of a congenital combined nevus showing unusual dermoscopic features.
Methods. Digital dermoscopic analysis was performed at the initial visit and after 8 months. The lesion was surgically excised and histopathologically examined.
Results. An asymptomatic plaque with a central blue area and peripheral brown pigmentation located on the back of a 13-year-old boy was diagnosed dermoscopically as combined nevus. Dermoscopic analysis 8 months later showed color changes from steel blue to gray-blue and black in the central area of the lesion, an increased number of blue-black dots or globules, and peripheral irregular streaks. Histopathology revealed typical features of a congenital combined nevus (blue nevus + compound nevus).
Conclusion. Over time, congenital combined nevus may show clinical and dermoscopic changes in size, color, and structure. Surgical excision is recommended when clinical and dermoscopic features are equivocal and the diagnosis of melanoma cannot be ruled out.
ANGELA FERRARI, MD, GIAN PIERO LOZZI, MD, MARIA CONCETTA FARGNOLI, MD, AND KETTY PERIS, MD, HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS.     

Immunoglobulin heavy chain Diversity genes rearrangement pattern indicates that MALT-type gastric lymphoma B cells have undergone an antigen selection process

Gastric MALT lymphoma usually develops from chronic gastritis, the vast majority of which (>90%) is associated with Helicobacter pylori infection. We sequenced the third complementarity determining region (CDR3) of immunoglobulin heavy chain genes in 19 gastric MALT lymphoma clones to determine the pattern of variable (V), diversity (D) and joining (J) gene utilization during immunoglobulin gene rearrangement.
DNA was extracted from paraffin-embedded sections and the rearranged CDR3 regions were amplified using a semi-nested polymerase chain reaction (with primers complementary to the conserved framework-three segment of the variable region [FR3A] and J regions). The DNA used for cloning and sequencing was obtained after purification of monoclonal bands excised from polyacrylamide gels. The N-D-N region specific to each clone was compared with known germline D sequences.
Similarly to that observed in normal and leukaemic B cells, our series of gastric MALT lymphomas showed apparent preferential utilization of genes from the DXP family. In two cases no similarity between the CDR3 nucleotide sequences of the neoplastic clones and the known germline D sequences could be found. In 10/19 analysed alleles the lymphoma B-cell clones appeared to contain two D gene segments (D-D recombination), a rare occurrence in normal individuals but one which has been described as a significant event in the determination of idiotype expression and antigen-binding affinity. Remarkably, despite the use of different D and J segments, the resultant amino acid sequences matched in two patients, suggesting the presence of a common selecting antigen.
The observed pattern of D gene rearrangement suggests that MALT lymphoma B-cell clones have undergone antigen selection, which seems to indicate that the antigen stimulation plays a pivotal role in the development of the lymphoma.     

Expanding the role of the ureteroscope

Although the rigid ureteroscope was designed exclusively for the diagnosis and treatment of pathological conditions of the ureter, its smaller diameter and extended length allow for its increased use in endoscopic procedures that cannot be performed successfully with a cystoscope. The indications can be divided into 3 categories: 1) difficult ureteral catheterizations, 2) augmented bladders and diverticula, and 3) narrow, strictured urethras and bladder necks. Several cases from each category are presented to illustrate the expanded role of the rigid ureteroscope in daily urological practice.