Liposomal Amphotericin B for Visceral Leishmaniasis in a Kidney Allograft Patient

Objective

To report a case of visceral leishmaniasis treated with liposomal amphotericin B (LAB) after probable failure with amphotericin B lipid complex (ABLC).

Case Summary

A 62-year-old white renal transplant recipient was admitted for pyrexia, hepato-splenomegaly, and pancytopenia. Leishmania amastigotes were detected from bone marrow aspirate and in circulating blood monocytes and neutrophils. The patient, who weighed 56 kg, received ABLC at a starting dose of 200 mg/d (3.6 mg/kg of body weight per day) for 13 days, achieving a total dose of 2,600 mg (46 mg/kg) without clinical improvement. The patient was switched to 100 mg/d (1.8 mg/kg) of LAB for 10 days, after which a dose of 250 mg (4.5 mg/kg) was repeated on days 17,24,31, and 38. Twenty-four hours after the first dose of LAB, the patient showed an excellent clinical response. On the following days, there was a progressive increase in hemoglobin concentration and leukocyte and platelet counts. Three months later, the patient was asymptomatic.

Discussion

Although treatment with ABLC appears to be effective for the treatment of Indian patients with visceral leishmaniasis, experience with immunocompromised patients is limited. This is the first case of a renal transplant recipient in which ABLC was used to treat visceral leishmaniasis without remarkable efficacy, but with infusion-related adverse effects perhaps due to the use of higher doses.

Conclusions

A randomized comparative trial is needed to compare LAB with ABLC in the treatment of visceral leishmaniasis in patients who have received kidney allografts.

Recent advances in synthesis, characterization of hydroxyapatite/polyurethane composites and study of their biocompatible properties

The development of engineered biomaterials that mimic bone tissues is a promising research area that benefits from a growing interest. Polymers and polymer-ceramic composites are the principle materials investigated for the development of synthetic bone scaffolds thanks to their proven biocompatibility and biostability. Several polymers have been combined with calcium phosphates (mainly hydroxyapatite) to prepare nanocomposites with improved biocompatible and mechanical properties. Here, we report the hydrothermal synthesis in high pressure conditions of nanostructured composites based on hydroxyapatite and polyurethane functionalized with carboxyl and thiol groups. Cell-material interactions were investigated for potential applications of these new types of composites as coating for orthopedic implants. Physical-chemical and morphological characteristics of hydroxyapatite/polyurethane composites were evaluated for different compositions, showing their dependence on synthesis parameters (pressure, temperature). In vitro experiments, performed to verify if these composites are biocompatible cell culture substrates, showed that they are not toxic and do not affect cell viability.

Nanoparticle encapsulation in red blood cells enables blood-pool magnetic particle imaging hours after injection

Magnetic particle imaging (MPI) is a new medical imaging approach that is based on the nonlinear magnetization response of super-paramagnetic iron oxide nanoparticles (SPIOs) injected into the blood stream. To date, real-time MPI of the bolus passage of an approved MRI SPIO contrast agent injected into the tail vein of living mice has been demonstrated. However, nanoparticles are rapidly removed from the blood stream by the mononuclear phagocyte system. Therefore, imaging applications for long-term monitoring require the repeated administration of bolus injections, which complicates quantitative comparisons due to the temporal variations in concentration. Encapsulation of SPIOs into red blood cells (RBCs) has been suggested to increase the blood circulation time of nanoparticles. This work presents first evidence that SPIO-loaded RBCs can be imaged in the blood pool of mice several hours after injection using MPI. This finding is supported by magnetic particle spectroscopy performed to quantify the iron concentration in blood samples extracted from the mice 3 and 24 h after injection of SPIO-loaded RBCs. Based on these results, new MPI applications can be envisioned, such as permanent 3D real-time visualization of the vessel tree during interventional procedures, bleeding monitoring after stroke, or long-term monitoring and treatment control of cardiovascular diseases.

Glucocorticoid resistance in Crohn's disease and ulcerative colitis: an association study investigating GR and FKBP5 gene polymorphisms

The aim of this study is to investigate the role of single-nucleotide polymorphisms (SNPs) of the glucocorticoid receptor (GR) and of the related co-chaperone FKBP5 genes in the development of glucocorticoid (GC) resistance in Crohn's disease (CD) and ulcerative colitis (UC) patients. We have developed a high-resolution DNA melting method that allows simultaneous identification of GR (BclI, N363S and ER22/23EK) and FKBP5 (rs3800373, rs1360780 and rs4713916) polymorphisms. Genotype frequencies were determined in 100 consecutive CD and 100 UC patients under GCs therapy (50 responders and 50 resisters). The variation of FKBP5 polymorphism rs4713916 (G/A), in the putative promoter region of FKBP5, is significantly associated with resistance to GC treatment in CD (responder=17% versus resister=35%; P=0.0043). No significant differences were found in UC patients. If these preliminary findings will be confirmed, the combination of GR and FKBP5 mutational analyses could help to identify subgroups of CD patients with higher chances to benefit from GC treatment.

Diagnosing tuberculosis in pregnancy: a case report

A case of miliary tuberculosis complicated by deciduitis and sub-chorionitis in a pregnant woman manifesting also influenza A/H1N1v infection and urinary tract infection is reported. Diagnosis of tuberculosis was obtained before delivery by examining amniotic fluid for Mycobacterium tuberculosis. Even though maternal symptoms did not suggest TB, diagnosis was early enough to start effective treatment in both the mother and the neonate and prevent in-hospital M.tuberculosis diffusion. A high index of suspicion by health professionals is required to detect and manage tuberculosis in pregnancy and newborns in both the developed and developing word.

Improved cellular uptake of functionalized single-walled carbon nanotubes

Single-walled carbon nanotubes (SWNTs) due to their unique structural and physicochemical properties, have been proposed as delivery systems for a variety of diagnostic and therapeutic agents. However, SWNTs have proven difficult to solubilize in aqueous solution, limiting their use in biological applications. In an attempt to improve SWNTs' solubility, biocompatibility, and to increase cell penetration we have thoroughly investigated the construction of carbon scaffolds coated with aliphatic carbon chains and phospholipids to obtain micelle-like structures. At first, oxidized SWNTs (2370 ± 30 nmol mg(-1) of SWNTs) were covalently coupled with an alcoholic chain (stearyl alcohol, C(18)H(37)OH; 816 nmol mg(-1) of SWNTs). Subsequently, SWNTs-COOC(18)H(37) derivatives were coated with phosphatidylethanolamine (PE) or -serine (PS) phospholipids obtaining micelle-like structures. We found that cellular uptake of these constructs by phagocytic cells occurs via an endocytotic mechanism for constructs larger than 400 nm while occurs via diffusion through the cell membrane for constructs up to 400 nm. The material that enters the cell by phagocytosis is actively internalized by macrophages and localizes inside endocytotic vesicles. In contrast the material that enters the cells by diffusion is found in the cell cytosol. In conclusion, we have realized new biomimetic constructs based on alkylated SWNTs coated with phospholipids that are efficiently internalized by different cell types only if their size is lower than 400 nm. These constructs are not toxic to the cells and could now be explored as delivery systems for non-permeant cargoes.

Effect of macrophage depletion on viral DNA rebound following antiretroviral therapy in a murine model of AIDS (MAIDS)

In the attempt to eradicate HIV-1 infection, a strategy to eliminate macrophages, one of the most important cellular reservoirs in sustaining virus replication during HAART, could be of great benefit in the suppression of viral rebound. Aware of the ability of clodronate to cause macrophage depletion, the effect of the administration of clodronate encapsulated in erythrocytes on disease progression and on viral rebound was evaluated in a murine model of AIDS (MAIDS). One group of LP-BM5 retroviral complex-infected C57BL/6 mice received oral administrations of azidothymidine and dideoxyinosine daily for 12 weeks; two other groups received in addition, either clodronate-loaded erythrocytes or free clodronate at 7-10 day intervals. At the end of the treatment, the three groups maintained parameters characterizing disease progression similar to those of uninfected mice and showed a significantly lower level of BM5d DNA than infected mice in all organs and cells tested. To assess the viral rebound, some animals were left for an additional 4 month period without any treatment. After this time, the BM5d DNA content in blood leukocytes increased in all groups, but the group having received clodronate-loaded erythrocytes, in addition to transcriptase inhibitors, showed a significant delay in viral rebound.

Low incidence of hepatotoxicity in a cohort of HIV patients treated with lopinavir/ritonavir

We describe the hepatotoxicity encountered in a cohort of HIV-positive patients treated with lopinavir/ritonavir. We used the database from the SCOLTA project, an on-line pharmacovigilance programme involving 25 Italian infectious disease centres. A total of 755 patients were followed, over a mean observation period of 16 months. The incidence of severe events was low despite the high prevalence of patients co-infected with hepatitis virus at enrollment.

[Epidemiological, clinical and therapeutical aspects of HIV/HCV coinfection in a series of HIV seropositive Umbrian patients]

Because hepatitis C virus (HCV) and human immunodeficiency virus (HIV) share common transmission pathways, HIV-HCV co-infection is frequent, involving about 40% of seropositive subjects particularly injection drug users and patients with hemophilia. We performed a retrospective analysis on clinical, epidemiological and therapeutical aspects in a population of HIV-HCV coinfected patients, observed in our Department during the period 2001-2003. Forty per cent of 404 observed patients had a co-infection; 90% of those were drug addicts and most (90.2%) were on HAART treatment. Seventy-three per cent of co-infected patients showed transaminases alterations, and 85% had detectable viremia. Prevalent genotypes were 1 (44.6%) and 3 (36.4%). The association PEG-IFN and ribavirine obtained sustained responses in 55% of 9 treated patients.