BCL-2 in primary central nervous system lymphomas. Immunohistochemistry and molecular biology

BCL-2 is a membrane protein known to be an apoptosis inhibitor. It is the product of the bcl-2 gene located on chromosome 18. Several different tumors show BCL-2 over-expression as result of a translocation or independently from it. More than 85% of follicular lymphomas and a smaller number of diffuse large cell B lymphomas contain t(14;18) (q32;q21). The aim of this study was to investigate the immunohistochemical expression of the BCL-2 protein and to ascertain, by means of traditional PCR (Polimerase Chain Reaction), its possible dependence from t(14;18) (q32;q21) in 9 primary central nervous system lymphomas. Six cases (67%) shoved immunohistochemical BCL-2 over-expression and 3 cases (33%) had t(14;18). Precisely: 2 cases (22%) had immunohistochemical BCL-2 over-expression and t(14;18) (q32;q21); 4 cases (44%) had BCL-2 over-expression without translocation; 1 case (11%) did not show diffuse BCL-2 over-expression in presence of the traslocation; the remaining 2 cases (22%) did not demonstrate BCL-2 over-expression or t(14;18) (q32;q21). In conclusion, our results indicate primary central nervous system lymphomas frequently show BCL-2 over-expression that in some case may be related to t(14;18) (q32;q21). Nevertheless, t(14;18) (q32;q21), as evaluated by traditional PCR, may not correspond to diffuse immunohistochemical BCL-2 positivity.     

Neonatal Williams syndrome presenting as an isolated supravalvular pulmonary stenosis

An infant with normal facies and none of the extracardiac anomalies usually associated with Williams syndrome presented at birth with an echocardiographic pattern of supravalvular pulmonary stenosis and displastic pulmonary valve. A clinical reappraisal was planned at 3 months of age, but the girl died suddenly at home at 2 months of age. At autopsy, both ventricles were hypertrophic, and the valves showed mild dysplasia. The walls of the great arteries were thick, with a "washed leather" consistency, but there was no gross evidence of discrete stenosis. The histologic mosaic appearance of the media of the great arteries, due to elastosis and extreme disarray of the elastic lamellae, prompted a postmortem diagnosis of supravalvar aortic stenosis and suggested a diagnosis of Williams syndrome, which was subsequently confirmed by fluorescence in situ hybridization. Pediatricians and pathologists should be alerted that Williams syndrome in the newborn may present as an isolated supravalvular pulmonary stenosis, whereas supravalvular aortic stenosis becomes clinically significant only a few months later.     

Anti-idiotypes against autoantibodies and alloantibodies to VIII:C (anti-haemophilic factor) are present in therapeutic polyspecific normal immunoglobulins.

Therapeutic, polyspecific, normal immunoglobulins (IVIg) suppress anti-factor VIII (VIII:C) activity of anti-VIII:c autoantibodies in vivo and in vitro. In the present study anti-VIII:C activity was found to be inhibited by two different preparations of IVIg in the plasma of three of four patients with autoantibodies and two of three patients with alloantibodies. F(ab')2 fragments from IVIg inhibited anti-VIII:C activity in F(ab')2 fragments from the plasma of the patients. In patients in whom anti-VIII:C activity was inhibited by IVIg, anti-VIII:C F(ab')2 antibodies were specifically retained on an affinity column of Sepharose-bound F(ab')2 from IVIg. In patients in whom anti-VIII:C activity was not suppressed by IVIg in vitro, no binding of anti-VIII:C antibodies to Sepharose-bound IVIg was observed. In a patient in whom anti-VIII:C activity was only suppressed by one preparation of IVIg, specific binding of anti-VIII:C antibodies was only observed with that preparation but not with another. These results indicate that IVIg contain anti-idiotypes against autoantibodies and alloantibodies to VIII:C. The capacity of IVIg to inhibit anti-VIII:C activity in vitro is directly related to the presence of demonstrable anti-idiotypes against anti-VIII:C antibodies. The finding of anti-idiotypes against anti-VIII:C alloantibodies in IVIg suggests that, in addition to autoantibodies, some alloantibodies may be suppressed in vivo by IVIg.     

Juvenile sudden death in a family with polymorphic ventricular arrhythmias caused by a novel RyR2 gene mutation: evidence of specific morphological substrates

We report on a family with a history of sudden death and effort-induced polymorphic ventricular arrhythmias. The index case was a 17-year-old boy who died suddenly and at postmortem had evidence of fibrofatty replacement in the right ventricular free wall, consistent with arrhythmogenic right ventricular cardiomyopathy, as well as calcium phosphate deposits within the myocytes. A molecular genetics investigation carried out in the paraffin-embedded myocardium of the subject and in blood samples of family members disclosed a missense mutation in exon 3 (230C-->T; A77V) of the cardiac ryanodine receptor type 2 gene. The carriers showed effort-induced polymorphic ventricular tachycardia in the setting of normal resting electrocardiogram and trivial echocardiographic abnormalities, consistent with catecholaminergic polymorphic ventricular tachycardia. The observation of both arrhythmogenic right ventricular cardiomyopathy type 2 and catecholaminergic polymorphic ventricular tachycardia in the same family suggests that the two entities might correspond to different degrees of phenotypic expression of the same disease. This experience underscores the importance of a precise autopsy diagnosis in the case of sudden cardiac death, including molecular genetics, and the mission of pathologists to guide further clinical investigation of family members.     

Effects of sildenafil (Viagra) administration on seminal parameters and post-ejaculatory refractory time in normal males

Sildenafil is a specific inhibitor of phosphodiesterase (PDE) type 5 and represents a powerful therapy for male erectile dysfunction (ED) of different aetiology. Recently, sildenafil has been shown to restore erections in temporary ED related to the need of semen collection for assisted reproductive techniques. In this study, we investigated whether sildenafil administration modifies seminal parameters and/or erectile function in normal healthy volunteers. In a double-blind, randomized, placebo-controlled, cross-over two period investigation we enrolled 20 healthy male volunteers (mean +/- SE age 32 +/- 0.5 years). Subjects were not using any medication for the 3 month period prior to the study and were engaged in a stable relationship with proven fertility. The effects of sildenafil (100 mg) on seminal parameters and erectile function after audiovisual sexual stimulation were evaluated by semen analysis and by colour-Duplex ultrasound (the Resistive Index) respectively. In all subjects, sildenafil caused no changes in seminal and erection parameters when compared to placebo. Interestingly, sildenafil administration led to a marked reduction of the post-ejaculatory refractory time (10.8 +/- 0.9 min versus 2.6 +/- 0.7 min for placebo and sildenafil respectively; P < 0.0001). These results indicate that in normal subjects acute sildenafil treatment does not modify semen characteristics and has a positive influence over the resumption of erections following ejaculation in the presence of a continuous erotic stimulus.     

A PCR-colorimetric microwell plate hybridization assay for detection of Mycobacterium tuberculosis and M. avium from culture samples and Ziehl-Neelsen-positive smears

Differentiation between Mycobacterium tuberculosis and M. avium is essential for the treatment of mycobacterial infections. We have developed an easy and rapid detection assay for the diagnosis of mycobacterial diseases. This is a PCR-hybridization assay based on selective amplification of a 16S rRNA gene sequence using pan-Mycobacterium primers followed by hybridization of the amplification products to biotinylated M. tuberculosis and M. avium-specific probes. A total of 55 mycobacterial isolates were tested. For all isolates, results concordant with those of conventional identification methods were obtained. Moreover, we developed a method for extraction of DNA from Ziehl-Neelsen-positive smears which allows the recovery of intact target DNA in our PCR-hybridization assay. Our method was able to confirm all culture results for 59 Ziehl-Neelsen-positive smears from clinical specimens (35 sputum, 11 lymph node biopsy, 6 stool, 4 pus, 2 urine, and 1 pericardial fluid specimens). These data suggest that our PCR-hybridization assay, which is simple to perform and less expensive than commercial probe methods, may be suitable for the identification of M. tuberculosis and M. avium. It could become a valuable alternative approach for the diagnosis of mycobacterial infections when applied directly to DNA extracted from Ziehl-Neelsen-positive smears as well.     

Recurrent "Flexispira rappini" bacteremia in an adult patient undergoing hemodialysis: case report

A blood culture from a 65-year-old febrile man undergoing hemodialysis revealed, 5 days after inoculation, an unusual gram-negative fusiform rod with darting motility. During another episode of fever 21 days later, this Campylobacter-like organism was again recovered from three blood cultures and subcultured under an H2-enriched microaerobic atmosphere. The organism was catalase negative and oxidase positive and hydrolyzed urea rapidly. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of whole-cell proteins was indistinguishable from that of "Flexispira rappini" LMG 8738 described by Archer et al. in 1988 (J. R. Archer, S. Romero, A. E. Ritchier, M. E. Hamacher, B. M. Steiner, J. H. Bryner, and R. F. Schell, J. Clin. Microbiol. 26:101-105, 1988). The analysis of the 16S ribosomal DNA sequence revealed a similarity of 99.3% between the two strains. The patient recovered completely after a 4-week course of meropenem therapy. This is the first reported case of a recurrent "F. rappini" bacteremia in an adult patient, which confirms that this organism may be an invasive pathogen in immunocompromised patients, like other newly described Helicobacter species.     

A nucleolar localizing Rev binding element inhibits HIV replication

The Rev protein of the human immunodeficiency virus (HIV) facilitates the nuclear export of intron containing viral mRNAs allowing formation of infectious virions. Rev traffics through the nucleolus and shuttles between the nucleus and cytoplasm. Rev multimerization and interaction with the export protein CRM1 takes place in the nucleolus. To test the importance of Rev nucleolar trafficking in the HIV-1 replication cycle, we created a nucleolar localizing Rev Response Element (RRE) decoy and tested this for its anti-HIV activity. The RRE decoy provided marked inhibition of HIV-1 replication in both the CEM T-cell line and in primary CD34+ derived monocytes. These results demonstrate that titration of Rev in the nucleolus impairs HIV-1 replication and supports a functional role for Rev trafficking in this sub-cellular compartment.