Evaluation of the humoral immune response and cross reactivity against <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> of mice immunized with liposomes containing glycolipids of <Emphasis Type="Italic">Mycobacterium smegmatis</Emphasis>

Mycobacterium smegmati s (Ms) is a nonpathogenic mycobacteria of rapid growth, which shares many characteristics with Mycobacterium tuberculosis (MTB), the major causative agent of tuberculosis. MTB has several cell wall glycolipids in common with Ms, which play an important role in the pathogenesis of tuberculosis and the induction of a protective immune response against MTB infection in some animal models. In this study, the humoral immune response and cross reactivity against MTB, of liposomes containing a mixture of cell wall glycolipids of Ms and commercial lipids was evaluated, in order to study its possible use as a component of a vaccine candidate against tuberculosis. Liposomes containing total lipids extracted from Ms, distearoyl phosphatidyl choline and cholesterol were prepared by the dehydration-rehydration technique. Balb/c mice were immunized with the liposomes obtained and the antibody response and cross reactivity against MTB were tested by ELISA. Total lipids extract from Ms showed the presence of several polar glycolipids in common with MTB, such as phosphatidylinositol mannosides. Liposomes that contained glycolipids of Ms were capable of inducing a specific IgG antibody response that allowed the recognition of surface antigens of MTB. The results of this study demonstrated the presence of immunogenic glycolipids in Ms, which could be included to enhance the protective effects of subunit vaccine formulations against tuberculosis.     

Evaluation of specific humoral immune response and cross reactivity against <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> antigens induced in mice immunized with liposomes composed of total lipids extracted from <Emphasis Type="Italic">Mycobacterium smegmatis</Emphasis>

The development of a new tuberculosis (TB) vaccine has become one of the main objectives of the scientific community. Protein antigens have been widely explored as subunit TB vaccines, however lipid antigens could be equally important to be used or included in such a vaccine. The aim of this study was to demonstrate the potential of a liposome formulation composed of an extract of lipids from Mycobacterium smegmatis (Ms) as a TB vaccine candidate. We evaluated the immunogenicity of this formulation as well as the cross reactive response against antigens from Mycobacterium tuberculosis (MTb) in BALB/c mice. We determined the anti-liposome IgG response in sera from TB patients and from healthy subjects who displayed a positive (PPD+) or negative (PPD-) tuberculin skin test. A significant increase in anti-liposome IgG (p<0.05) was detected in animals immunized with Bacille Calmette-Guérin (BCG) compared with all groups, and in the group immunized with liposomes from Ms (LMs) compared to animals immunized with either LMs adjuvanted with aluminium (LMs-A) or the negative control group (phosphate buffered saline, PBS) respectively. With respect to the cross reactive response against a cocktail of cell wall antigens (CWA) from MTb, significantly higher IgG levels were observed in animals immunized with BCG and LMs compared to negative controls and either, aluminium-adjuvanted liposomes (LMs-A) or montanide (LMs-M) (p<0.05). Furthermore, the anti-liposome IgG response was significantly superior in sera from pulmonary TB patients compared to PPD+ and PPD- healthy subjects (p<0.001) suggesting the expression of these antigens in vivo during active MTb infection. The results obtained provide some evidence for the potential use of liposomes containing total lipid extracts of Ms as a TB vaccine candidate.     

Need of vascular surgeon and comparison of value for anterior lumbar interbody fusion (ALIF) in lateral decubitus: Delphi consensus

European Spine Journal - Anterior lumbar approaches are recommended for clinical conditions that require interbody stability, spinal deformity corrections or a large fusion area. Anterior lumbar...     

The man who feels two hearts: the different pathways of interoception

Recent advances in neuroscience have provided new insights into the understanding of heart–brain interaction and communication. Cardiac information to the brain relies on two pathways, terminating in the insular cortex (IC) and anterior cingulate cortex (ACC), along with the somatosensory cortex (S1-S2). Interoception relying on these neuroanatomical pathways has been shown to modulate social cognition. We report the case study of C.S., a patient with an ‘external heart’ (an extracorporeal left-univentricular cardiac assist device, LVAD). The patient was assessed with neural/behavioral measures of cardiac interoception complemented by neuropsychological and social cognition measures. The patient’s performance on the interoception task (heartbeat detection) seemed to be guided by signals from the artificial LVAD, which provides a somatosensory beat rather than by his endogenous heart. Cortical activity (HEP, heartbeat-evoked potential) was found decreased in comparison with normal volunteers, particularly during interoceptive states. The patient accurately performed several cognitive tasks, except for interoception-related social cognition domains (empathy, theory of mind and decision making). This evidence suggests an imbalance in the patient’s cardiac interoceptive pathways that enhances sensation driven by the artificial pump over that from the cardiac vagal-IC/ACC pathway. A patient with two hearts, one endogenous and one artificial, presents a unique opportunity to explore models of interoception and heart–brain interaction.     

Anticancer activity of pyrimidodiazepines based on 2-chloro-4-anilinoquinazoline: synthesis,DNA binding and molecular docking

Multidrug resistance to chemotherapy is a critical health problem associated with mutation of the therapeutic target. Therefore, the development of anticancer agents remains a challenge to overcome cancer cell resistance. Herein, a new series of quinazoline-based pyrimidodiazepines 16a–g were synthesized by the cyclocondensation reaction of 2-chloro-4-anilinoquinazoline-chalcones 14a–g with 2,4,5,6-tetraaminopyrimidine. All quinazoline derivatives 14a–g and 16a–g were selected by the U.S. National Cancer Institute (NCI) for testing their anticancer activity against 60 cancer cell lines of different panels of human tumors. Among the tested compounds, quinazoline-chalcone 14g displayed high antiproliferative activity with GI₅₀ values between 0.622–1.81 μM against K-562 (leukemia), RPMI-8226 (leukemia), HCT-116 (colon cancer) LOX IMVI (melanoma), and MCF7 (breast cancer) cancer cell lines. Additionally, the pyrimidodiazepines 16a and 16c exhibited high cytostatic (TGI) and cytotoxic activity (LC₅₀), where 16c showed high cytotoxic activity, which was 10.0-fold higher than the standard anticancer agent adriamycin/doxorubicin against ten cancer cell lines. COMPARE analysis revealed that 16c may possess a mechanism of action through DNA binding that is similar to that of CCNU (lomustine). DNA binding studies indicated that 14g and 16c interact with the calf thymus DNA by intercalation and groove binding, respectively. Compounds 14g, 16c and 16a displayed strong binding affinities to DNA, EGFR and VEGFR-2 receptors. None of the active compounds showed cytotoxicity against human red blood cells.

A new series of quinazoline-based chalcones and pyrimidodiazepines were tested against 60 human tumor cell lines.     

Testosterone Levels Are Decreased and Associated with Disease Duration in Male Spinocerebellar Ataxia Type 2 Patients

The Cerebellum - Spinocerebellar ataxia type 2 (SCA2) is a progressive neurodegenerative disorder due to an unstable expansion of a CAG repeat in the ATXN2 gene. Despite clinical and experimental...     

Histologic findings of disc, end plate and neural elements after coblation of nucleus pulposus: an experimental nucleoplasty study

BACKGROUND CONTEXT: Partial removal of the nucleus has been shown to decompress herniated discs, relieving pressure on nerve roots and, in some cases, offering relief from disc pain. The nucleoplasty technique builds on earlier surgical approaches that helped validate the strategy of intranuclear tissue removal. Nucleoplasty, a new minimally invasive procedure using patented coblation technology, combines coagulation and ablation for partial removal of the nucleus pulposus to decompress the disc. PURPOSE: To determine if histologic changes of the intervertebral discs and surrounding tissues occur after nucleoplasty. STUDY DESIGN: A light microscopic study of intervertebral disc and adjacent neural tissues after disc decompression by nucleoplasty in pig cadavers. METHODS: Light microscopy was used to examine disc and neural tissues in two pig cadaveric specimens (T12 to sacrum). Nucleoplasty was performed by 1) advancing a radiofrequency wand to a predetermined depth in the disc (ablation), and 2) withdrawing the wand to the starting point (coagulation). Discs and adjacent tissues were removed from treated and nontreated segments, and examined under light microscopy. RESULTS: Histologic examination revealed no evidence of direct mechanical or thermal damage to the surrounding tissues. There was clear evidence of coblation channels with clean coagulation borders of the nucleus pulposus. Normal histologic findings of the annulus and end plate, with normal neural elements of the spinal cord and nerve roots at the level of the procedure, were observed. CONCLUSIONS: The histologic findings of this study suggest that the nucleoplasty achieves volumetric removal of target disc tissue without overt thermal or structural damage to the adjacent tissues. Further studies in live animals will be needed to assess the effects of nucleoplasty on the annulus, end plate and neural tissues under physiologic conditions, including assessment of cell viability.     

Immunization of mice with Neisseria meningitidis serogroup B genomic expression libraries elicits functional antibodies and reduces the level of bacteremia in an infant rat infection model

The feasibility of expression library immunization against the pathogenic bacterium Neisseria meningitidis was studied. A genomic library of N. meningitidis serogroup B strain CU385, containing 6000 individual clones, was constructed and divided into 10 sublibraries. Immunization of BALB/c mice with plasmid DNA from six sublibraries induced a humoral response, with recognition of several meningococcal proteins by Western blot. Three of these sublibraries elicited bactericidal antibodies against the homologous strain, and sera from mice immunized with one of these sublibraries reduced significantly the number of viable bacteria in blood of infant rats challenged with N. meningitidis. In addition, after DNA immunization, mice were boosted intraperitoneally with 5 x 10(2) colony forming units of strain CU385. Mice immunized with nine of the 10 libraries developed bactericidal antibodies 1 week after the boost and controls did not, demonstrating the priming capacity and specificity of our immunization strategy. Our study demonstrates, for the first time, that genomic immunization offers a novel approach for screening possible vaccine candidates against N. meningitidis.     

Endoscopic selective neck dissection in a porcine model

OBJECTIVE: To investigate the feasibility of accomplishing a selective neck dissection (SND) endoscopically. STUDY DESIGN: Prospective, nonrandomized experimental investigation in a porcine model. METHODS: Unilateral endoscopic SNDs were performed in Yorkshire pigs. A spacious operative pocket was developed using a combination of hernia balloon expansion followed by low-pressure (4 mm Hg) carbon dioxide insufflation. The sternomastoid muscle, thymus, submandibular gland, lymph nodes, and fibrofatty tissue were removed in a procedure approximating a human SND. Data (operative time, blood loss, arterial blood gas values, weight of the specimen, and complications) were prospectively recorded. The specimens were analyzed by a pathologist, and the number and size of lymph nodes were recorded. RESULTS: Fourteen endoscopic SNDs were successfully performed. No conversions to open surgery were necessary. The median operative time was 131 minutes (range, 95-235 minutes). The median estimated blood loss was 4 mL (range, 0-150 mL). The mean +/- SD specimen weight was 42.9 +/- 8.3 g; the mean number +/- SD of nodes retrieved from the neck specimen was 4.8 +/- 2.2, and the mean +/- SD maximal nodal dimension was 2.4 +/- 0.5 cm. The arterial PCO2 increased by an average of only 3.9 mm Hg from the beginning to the end of the surgery; correspondingly, the pH fell by only 0.02. There were no major complications, and no animals had to be euthanized prior to the completion of the procedure. CONCLUSIONS: Endoscopic neck dissection in a porcine model can be accomplished with a combination of strategies to overcome the dilemma of creating and maintaining an operative pocket. The merger of SND with endoscopic technology offers the promise of truly minimally invasive surgery for the node-negative neck.