Importance of divalent cations in nanolipoplex gene delivery

Gene therapy is a promising therapeutic strategy to combat genetic or acquired diseases at their root cause rather than just treating symptoms. It is well recognised that there is an urgent need for non-toxic and efficient gene delivery vectors to fully exploit the current potential of gene therapy in molecular medicine. Cell-specific targeting of bioactive nucleotides is a prerequisite to attain the concentration of nucleic acids required for therapeutic efficacy in the target tissue. Many metal ions such as Mg2+, Mn2+, Ba2+ and, most importantly, Ca2+ have been demonstrated to have significant roles in gene delivery. These inorganic cations show low toxicity, good biocompatibility and promise for controlled delivery properties, thus presenting a new alternative to toxic and immunogenic carriers. Recently, inorganic nanoparticles alone, or in combination with a colloidal particulate system such as nanoliposome, an advanced approach to gene delivery, were found to exert a positive effect on gene transfer. In this report, the role of the divalent cations in nucleic acid delivery, particularly with respect to the potential improvement of transfection efficiency of nanolipoplexes, is reviewed.     

Strain-specific differences in two large Mycobacterium tuberculosis genotype clusters in isolates collected from homeless patients in New York City from 2001 to 2004

We studied two large Mycobacterium tuberculosis genotype clusters associated with recent outbreaks in homeless persons to determine factors associated with these tuberculosis (TB) strains. Isolates from all culture-positive TB cases diagnosed from 1 January 2001 to 31 December 2004 were genotyped. Patients whose isolates had identical restriction fragment length polymorphism patterns and spoligotypes were considered clustered. Health department records were reviewed and reinterviews attempted for clustered cases. Patients with the Cs30 and BEs75 strains were compared to other genotypically clustered cases and to each other. The two largest genotype clusters among homeless persons were the Cs30 strain (n = 105) and the BEs75 strain (n = 47). Fifty-one (49%) patients with the Cs30 strain and 28 (60%) with the BEs75 strain were homeless. Compared to patients with the BEs75 strain, patients with the Cs30 strain were less likely to be respiratory acid-fast bacillus smear positive (51% versus 72%). Furthermore, patients with the BEs75 strain were more likely to be HIV infected (74% versus 42%), which suggests that most patients with this strain advanced to disease after recent infection. Cases in clusters of strains that have been circulating in the community over a long time period, such as the Cs30 strain, require additional investigation to determine whether clustering is a result of recent transmission or reactivation of remote infection.     

Cholera toxin indirectly activates human monocyte-derived dendritic cells in vitro through the production of soluble factors, including prostaglandin E(2) and nitric oxide

Cholera toxin (CT) is a potent adjuvant that activates dendritic cells (DC) by increasing intracellular cyclic AMP (cAMP) levels. In vivo and in vitro, very small amounts of CT induce potent adjuvant effects and activate DC. We hypothesized that DC intoxicated by CT may release factors that enhance their own maturation and induce the maturation of toxin-free bystander DC. Through the use of mixed cultures and transwell cultures, we found that human monocyte-derived DC (MDDC) pulsed with CT or other cAMP-elevating agonists induce the maturation of bystander DC. Many DC agonists including CT increase the production of prostaglandin E(2) (PGE(2)) and nitric oxide (NO). For this reason, we determined whether the actions of PGE(2) or NO are involved in the maturation of MDDC induced by CT or dibutyryl-cAMP (d-cAMP). We found that blocking the production of PGE(2) or blocking prostaglandin receptors inhibited MDDC maturation induced by CT and d-cAMP. Likewise, sequestering NO or blocking the downstream actions of NO resulted in the inhibition of MDDC maturation induced by CT and d-cAMP. These results indicate that endogenously produced factors including PGE(2) and NO contribute to the maturation of DC induced by CT and that these factors participate in bystander DC maturation. The results of this study may help explain why bacterial toxins that elevate cAMP are such potent adjuvants.     

Gastroprotective activities of Turnera diffusa Willd. ex Schult. revisited: Role of arbutin

Ethnopharmacological relevance

Turnera diffusa Willd. ex Schult. has been used for the treatment of several human disorders including peptic ulcer.

Objectives of the study

The current study is an attempt to evaluate the anti-ulcerogenic activities of arbutin, a major constituent of Turnera diffusa on two ulcer models. The possible involvement of lipid peroxidation, nitric oxide, IL-6, IL-10, TNF-α and mucus barrier mechanism has been investigated.

Materials and methods

Effects of arbutin on ulcer index, gastric juice acidity, mucus content and histochemistry, gross and histological gastric lesions, nitric oxide, cytokines levels (IL-6, IL-10 and TNF-α), and thiobarbituric acid reactive substances (TBARS), were evaluated in aspirin or ethanol-induced ulcer in vivo. Acute toxicity of arbutin was also examined in rodent model. MTT assay was used to assess the cytotoxicity of the compound on normal liver cells (WRL-68).

Results

Pre-treatment with arbutin or omeprazole protected the gastric mucosa as seen by reduction in ulcer area and mucosal content, reduced or absence of edema, inflammation and leucocytes infiltration on both models. Arbutin significantly (P < 0.05) lowered the elevated TBARS level into gasteric homogenate. Arbutin did not produce significant inhibition of NO. This natural compound has modulated the levels of interleukin-6, interleukin-10 and TNF-α. No in vitro or in vivo toxicities for arbutin were observed.

Conclusion

Thus it can be concluded that Turnera diffusa possesses anti-ulcer activity, which could be attributed to lipid peroxidation inhibitory, immuno modulatory and anti-oxidant mechanisms of arbutin but not to the intervention with nitric oxide inflammation pathway.     

Intranervous immunoglobulin deposits: an underestimated mechanism of neuropathy

There are several pathogenic mechanisms of peripheral nerve involvement in patients with monoclonal dysglobulinemia. Intranervous proliferation of malignant cells, immunoglobulin, or amyloid deposits in the endoneurial space can only be determined by examination of nerve biopsy specimens. We present clinical, electrophysiological, and histological data from seven patients whose polyneuropathy was induced by immunoglobulin deposits in the endoneurial space. As these lesions cannot be demonstrated on clinical and electrophysiological grounds, the indication for nerve biopsy derives from careful analysis of each patient presenting with a polyneuropathy and a monoclonal dysglobulinemia. To visualize and clearly characterize these deposits, electron microscopic examination is indispensable. Immunocytochemical methods using both light and electron microscopy for ultrastructural analysis are of great value. Demonstration of endoneurial immunoglobulin deposits may have major therapeutic consequences. Indeed, identification of these deposits prompted the use of aggressive treatment, which was quite effective in five of our seven patients.     

Giant cell tumor complicating Paget disease of long bone

Giant cell tumor (GCT) is a rare complication of Paget disease of bone. It usually occurs in the skull or pelvic bones of patients with long-standing polyostotic disease. This report describes a 62-year-old patient who presented with monostotic Paget disease of the distal femur complicated by GCT. He had a 2-year history of discomfort and pain in his left knee. Conventional plain films and MRI demonstrated the characteristic bone changes of Paget disease and an associated lytic lesion involving the epiphyseal and metaphyseal regions of the distal femur. A diagnostic curettage showed the characteristic histopathologic features of Paget disease and GCT. There was no evidence of malignancy. The clinicopathologic features of this rare lesion are described and correlated with a review of the literature.     

Epstein-barr virus genotypes in NPC biopsies from North Africa

The genotypes of Epstein-Barr virus (EBV) were investigated in North African nasopharyngeal carcinoma (NPC) biopsies, nasopharyngeal chronic inflammation (NCI) biopsies, and saliva of healthy individuals from Algeria and Tunisia where there is an intermediate incidence of NPC. The prevalence of A-type virus in NPC, NCI biopsies and saliva of healthy individuals was found in these regions by means of a PCR assay. Restriction enzyme polymorphism analysis by Southern blotting revealed that all North African EBV variants have a conserved restriction site on BamHI W'-1′ and XhoI LMP gene. No additional BamHI enzyme site on the BamHI-F fragment was observed; however, the presence of an extra BamHI site on the BamHI-H fragment giving 2 H1 and H2 fragment-like EBV M-ABA strains was found. All EBV strains present in NPC or NCI biopsies at all ages were homogeneous in these polymorphisms and no correlation was observed between the EBV genotypes from NPC patients and clinical stages of the cancer. These characteristics revealed a significant difference between the EBV variants common in Chinese NPC and those in North African NPC.     

Glomus tumor of the thigh: confluent with the periosteum of the femur

True glomus tumor is rare. In the majority of cases it involves the hand, preferring the fingertips or nail beds. We report a patient with glomus tumor of the mid-thigh who presented with severe localized pain and limp. The imaging features are discussed and the English literature reviewed.     

True bursal pigmented villonodular synovitis

We describe two cases of pigmented villonodular synovitis affecting true bursae. This study was also designed to discuss the term "pigmented villonodular bursitis", not confined to true synovial bursae, sometimes creating misunderstanding.