16 research outputs found
Anti-mycobacterial recall responses differentiate female patients with genital tuberculosis from patients with other gynecological problems
Background: Female Genital Tuberculosis (FGTB) is one form of extra pulmonary tuberculosis affecting the female reproductive organs, most commonly the fallopian tubes and the endometrium. It affects young women aged between 20 and 40 years of age and is an important cause of infertility. It often occurs as a secondary complication following pulmonary tuberculosis. Diagnosis depends mainly on clinical suspicion in countries where facilities for mycobacterial culture and histopathology are unavailable. Even in places where these facilities exist, diagnosis still remains difficult because of the lower sensitivity and specificity of the methods as well as the invasive procedure of acquiring biopsy specimens. Objective: To explore the immunological profiles of female genital tuberculosis (FGTB) patients in response to mycobacterial antigens. Methods: Twenty-five clinically suspected cases of FGTB and 12 control subjects who came to the Black Lion hospital for unrelated gynecological problems were included in the study. Peripheral blood samples were collected from each subject. Plasma was separated by centrifugation and PBMC were isolated over ficoll-hypaque and stimulated in vitro with mycobacterial antigens to examine their proliferative response as incorporation of tritiated thymidine using a β-counter. HIV status and total IgG-, IgA- and IgM- antibody levels were determined by ELISA tests.Results: In vitro recall responses to M. tuberculosis antigens (PPD and BCG sonicate) as well as plasma levels of IgGIgA- and IgM-antibodies to MPT59 showed statistically significant differences between the patients and the controls (
Evaluation of a direct colorimetric assay for rapid detection of rifampicin resistant Mycobacterium tuberculosis
No Abstract Available
Ethiop.J.Health Dev. Vol.19(1) 2005: 51-5
Novel approaches toward the development of an oral post-exposure DNA vaccine for latent tuberculosis using Salmonella typhimurium ΔaroA vector
Tuberculosis remains one of the major causes of global public health problems. There is no effective vaccine for the disease until now. Many reports show that DNA vaccines are promising to induce protection against Mycobacterium tuberculosis (M. tb); however, the efficiency of DNA vaccine is limited due to inadequate delivery systems. Among others, live attenuated bacterial vectors such as Salmonella enterica typhimurium (S. typhimurium) have significant promise as efficient mucosal delivery vehicles for DNA vaccines. In this study, we constructed recombinant attenuated S. typhimurium DNA vaccines carrying genes encoding resuscitation promoting factor (Rpf)-like proteins of M. tb on eukaryotic expression plasmid agianst latent tuberculosis and evaluated the plasmid stability and growth curve assays of the recombinant Salmonella vaccine constructs in vitro. Four Rpf gene fragments (RpfB, RpfC, RpfD, RpfE) associated with latency were amplified from genomic DNA of the H37Rv strain of M. tb, cloned into eukaryotic expression plasmid (pVR1020) and verified by sequencing. In later studies, we will demonstrate the potential use of the Salmonella-mediated DNA constructs as candidate post-exposure vaccines against tuberculosis through testing their immunogenicity and effectiveness for oral delivery in eukaryotic systems.Key words: Latent tuberculosis, resuscitation promoting factor (Rpf), DNA vaccine, recombinant Salmonella typhimurium
Impact of hepatitis C virus co-infection on HIV patients before and after highly active antiretroviral therapy: an immunological and clinical chemistry observation, Addis Ababa, Ethiopia
Clinical, molecular and drug sensitivity pattern of mycobacterial isolates from extra-pulmonary tuberculosis cases in Addis Ababa, Ethiopia
Impact of hepatitis C virus co-infection on HIV patients before and after highly active antiretroviral therapy: an immunological and clinical chemistry observation, Addis Ababa, Ethiopia
Encapsulation of Gadolinium Oxide Nanoparticle (Gd<sub>2</sub>O<sub>3</sub>) Contrasting Agents in PAMAM Dendrimer Templates for Enhanced Magnetic Resonance Imaging <i>in Vivo</i>
There
has been growing interest in the research of nanomaterials
for biomedical applications in recent decades. Herein, a simple approach
to synthesize the G4.5-Gd<sub>2</sub>O<sub>3</sub>-polyÂ(ethylene glycol)
(G4.5-Gd<sub>2</sub>O<sub>3</sub>-PEG) nanoparticles (NPs) that demonstrate
potential as dual (<i>T</i><sub>1</sub> and <i>T</i><sub>2</sub>) contrasting agents in magnetic resonance imaging (MRI)
has been reported in this study. Compared to the clinically popular
Gd-DTPA contrasting agents, G4.5-Gd<sub>2</sub>O<sub>3</sub>-PEG NPs
exhibited a longer longitudinal relaxation time (<i>T</i><sub>1</sub>) and better biocompatibility when incubated with macrophage
cell line RAW264.7 <i>in vitro</i>. Furthermore, the longitudinal
relaxivity (<i>r</i><sub>1</sub>) of G4.5-Gd<sub>2</sub>O<sub>3</sub>-PEG NPs was 53.9 s<sup>–1</sup> mM<sup>–1</sup> at 7T, which is equivalent
to 4.8 times greater than to the Gd-DTPA contrasting agents. An <i>in vivo</i> <i>T</i><sub>1</sub>-weighted MRI results
revealed that G4.5-Gd<sub>2</sub>O<sub>3</sub>-PEG NPs significantly
enhanced signals in the intestines, kidney, liver, bladder, and spleen.
In addition, the <i>T</i><sub>2</sub>-weighted MRI results revealed
darker contrast in the kidney, which proves that G4.5-Gd<sub>2</sub>O<sub>3</sub>-PEG NPs can be exploited as <i>T</i><sub>1</sub> and <i>T</i><sub>2</sub> contrasting agents. In
summary, these findings suggest that the G4.5-Gd<sub>2</sub>O<sub>3</sub>-PEG NPs synthesized by an alternative approach can be used
as dual MRI contrasting agents
IL‑6 Antibody and RGD Peptide Conjugated Poly(amidoamine) Dendrimer for Targeted Drug Delivery of HeLa Cells
In this study, PAMAM dendrimer (G4.5)
was conjugated with two targeting
moieties, IL-6 antibody and RGD peptide (G4.5-IL6 and G4.5-RGD conjugates).
Doxorubicin anticancer drug was physically loaded onto G4.5-IL6 and
G4.5-RGD with the encapsulation efficiency of 51.3 and 30.1% respectively.
The cellular internalization and uptake efficiency of G4.5-IL6/DOX
and G4.5-RGD/DOX complexes was observed and compared by confocal microscopy
and flow cytometry using HeLa cells, respectively. The lower IC<sub>50</sub> value of G4.5-IL6/DOX in comparison to G4.5-RGD/DOX is indication
that higher drug loading and faster drug release rate corresponded
with greater cytotoxicity. The cytotoxic effect was further verified
by increment in late apoptotic/necrotic cells due to delivery of drug
through receptor-mediated endocytosis. On the basis of these results,
G4.5-IL6 is a better suited carrier for targeted drug delivery of
DOX to cervical cancer cells
Bioinspired, Manganese-Chelated Alginate–Polydopamine Nanomaterials for Efficient in Vivo <i>T</i><sub>1</sub>‑Weighted Magnetic Resonance Imaging
Manganese-based
nanomaterials are an emerging new class of magnetic
resonance imaging (MRI) contrast agents (CAs) that provide impressive
contrast abilities. MRI CAs that can respond to pathophysiological
parameters such as pH or redox potential are also highly in demand
for MRI-guided tumor diagnosis. Until now, synthesizing nanomaterials
with good biocompatibility, physiochemical stability, and good contrast
effects remains a challenge. This study investigated two new systems
of calcium/manganese cations complexed with either alginate–polydopamine
or alginate–dopamine nanogels [AlgPDAÂ(Ca/Mn) NG or AlgDAÂ(Ca/Mn)
NG]. Under such systems, Ca cations form ionic interactions via carboxylic
acids of the Alg backbone to enhance the stability of the synthetic
nanogels (NGs). Likewise, complexation of Mn cations also increased
the colloidal stability of the synthetic NGs. The magnetic property
of the prepared CAs was confirmed with superconducting quantum interference
device measurements, proving the potential paramagnetic property.
Hence, the <i>T</i><sub>1</sub> relaxivity measurement showed
that PDA-complexed synthetic NGs reveal a strong positive contrast
enhancement with <i>r</i><sub>1</sub> = 12.54 mM<sup>–1</sup>·s<sup>–1</sup> in 7.0 T MRI images, whereas DA-complexed
synthetic NGs showed a relatively lower <i>T</i><sub>1</sub> relaxivity effect with <i>r</i><sub>1</sub> = 10.13 mM<sup>–1</sup>·s<sup>–1</sup>. In addition, both the
synthetic NGs exhibit negligible cytotoxicity with >92% cell viability
up to 0.25 mM concentration, when incubated with the mouse macrophage
(RAW 264.7) and HeLa cells, and high biocompatibility under in vivo
analysis. The in vivo MRI test indicates that the synthetic NG exhibits
a high signal-to-noise ratio for longer hours, which provides a longer
image acquisition time for tumor and anatomical imaging. Furthermore, <i>T</i><sub>1</sub>-weighted MRI results revealed that PEGylated
AlgPDAÂ(Ca/Mn) NGs significantly enhanced the signals from liver and
tumor tissues. Therefore, owing to the enhanced permeability and retention
effect, significantly enhanced in vitro and in vivo imagings, low
cost, and one-pot synthesis method, the Mn-based biomimetic approach
used in this study provides a promising and competitive alternative
for noninvasive tumor detection and comprehensive anatomical diagnosis