Immune regulatory effect of pHSP65 DNA therapy in pulmonary tuberculosis: activation of CD8+ cells, interferon-gamma recovery and reduction of lung injury

A DNA vaccine based on the heat-shock protein 65 Mycobacterium leprae gene (pHSP65) presented a prophylactic and therapeutic effect in an experimental model of tuberculosis. In this paper, we addressed the question of which protective mechanisms are activated in Mycobacterium tuberculosis-infected mice after immune therapy with pHSP65. We evaluated activation of the cellular immune response in the lungs of infected mice 30 days after infection (initiation of immune therapy) and in those of uninfected mice. After 70 days (end of immune therapy), the immune responses of infected untreated mice, infected pHSP65-treated mice and infected pCDNA3-treated mice were also evaluated. Our results show that the most significant effect of pHSP65 was the stimulation of CD8+ lung cell activation, interferon-gamma recovery and reduction of lung injury. There was also partial restoration of the production of tumour necrosis factor-alpha. Treatment with pcDNA3 vector also induced an immune stimulatory effect. However, only infected pHSP65-treated mice were able to produce significant levels of interferon-gamma and to restrict the growth of bacilli.

Leishmanial antigens in the diagnosis of active lesions and ancient scars of American tegumentary leishmaniasis patients

Cutaneous biopsies (n = 94) obtained from 88 patients with American tegumentary leishmaniasis were studied by conventional and immunohistochemical techniques. Specimens were distributed as active lesions of cutaneous leishmaniasis (n = 53) (Group I), cicatricial lesions of cutaneous leishmaniasis (n = 35) (Group II) and suggestive scars of healed mucosal leishmaniasis patients (n = 6) (Group III). In addition, active cutaneous lesions of other etiology (n = 24) (Group C1) and cutaneous scars not related to leishmaniasis (n = 10) (Group C2) were also included in the protocol. Amastigotes in Group I biopsies were detected by routine histopathological exam (30.2%), imprint (28.2%), culture (43.4%), immunofluorescence (41.4%) and immunoperoxidase (58.5%) techniques; and by the five methods together (79.3%). In Group II, 5.7% of cultures were positive. Leishmanial antigen was also seen in the cytoplasm of macrophages and giant cells (cellular pattern), vessel walls (vascular pattern) and dermal nerves (neural pattern). Positive reaction was detected in 49 (92.5%), 20 (57%) and 4 (67%) biopsies of Groups I, II and III, respectively. Antigen persistency in cicatricial tissue may be related to immunoprotection or, on the contrary, to the development of late lesions. We suggest that the cellular, vascular and neural patterns could be applied in the immunodiagnosis of active and cicatricial lesions in which leishmaniasis is suspected.

Tissue distribution of a plasmid DNA encoding Hsp65 gene is dependent on the dose administered through intramuscular delivery

In order to assess a new strategy of DNA vaccine for a more complete understanding of its action in immune response, it is important to determine the in vivo biodistribution fate and antigen expression. In previous studies, our group focused on the prophylactic and therapeutic use of a plasmid DNA encoding the Mycobacterium leprae 65-kDa heat shock protein (Hsp65) and achieved an efficient immune response induction as well as protection against virulent M. tuberculosis challenge. In the present study, we examined in vivo tissue distribution of naked DNA-Hsp65 vaccine, the Hsp65 message, genome integration and methylation status of plasmid DNA. The DNA-Hsp65 was detectable in several tissue types, indicating that DNA-Hsp65 disseminates widely throughout the body. The biodistribution was dose-dependent. In contrast, RT-PCR detected the Hsp65 message for at least 15 days in muscle or liver tissue from immunized mice. We also analyzed the methylation status and integration of the injected plasmid DNA into the host cellular genome. The bacterial methylation pattern persisted for at least 6 months, indicating that the plasmid DNA-Hsp65 does not replicate in mammalian tissue, and Southern blot analysis showed that plasmid DNA was not integrated. These results have important implications for the use of DNA-Hsp65 vaccine in a clinical setting and open new perspectives for DNA vaccines and new considerations about the inoculation site and delivery system.

Interleukin-12: an immunoregulatory cytokine produced by B cells and antigen-presenting cells

Interleukin 12 (IL-12) is a heterodimeric protein produced by B cells, phagocytic cells, and other antigen-presenting cells. IL-12 was originally purified from the supernatant fluids of human EBV-transformed cell lines and later observed to be produced by the large majority of such cell lines, especially and at high levels from those derived from AIDS-associated lymphomas. However, phagocytic cells rather than B cells appear to be the most important physiological producers of IL-12. There are two pathways of IL-12 induction in phagocytic cells: a T-cell-independent one, induced primarily by bacteria, bacterial products, or intracellular parasites and important in the early inflammatory response of innate resistance; and a T-cell-dependent one, induced by the interaction of CD40L on activated T cells with CD40 receptor on IL-12-producing cells (phagocytic cells and antigen-presenting cells) and important in the regulation of adaptive immunity. IL-12 induces production of cytokines, especially interferon-gamma, from both T and NK cells, enhances the cytotoxic activity of NK cells and the generation of cytotoxic T cells, and has a proliferative activity on T and NK cells. Both in vivo and in vitro, IL-12 is a powerful inducer of T helper type 1 (Th1) response, whereas it inhibits Th2-type responses.

Immune complex glomerulonephritis in experimental kala-azar

In the present work we demonstrate that hamsters infected with L. donovani eliminate large quantities of immunoglobulins in the urine. This alteration is clearly a consequence of a conspicuous immune complex glomerulonephritis readily detectable 7 days after the beginning of infection. L. donovani antigens and hamsters immunoglobulins (Igs) were revealed as granular deposits in the mesangial areas and contiguous loops of the glomeruli. Histopathological alterations such as focal mesangial proliferation with progression to diffuse proliferation were observed in the first 3 weeks of infection. From day 35 onwards, all diseased animals presented large deposits of amyloid material of predominantly glomerular localization. In consonance with these alterations, Igs were detected in the urine by day 21 of infection and their concentration increased substantially with the progression of disease. In contrast, serum Igs increased until day 21, when their concentration dropped steadily.

Wetting at nonplanar substrates: unbending and unbinding

We consider fluid wetting on a corrugated substrate using effective interfacial Hamiltonian theory and show that breaking the translational invariance along the wall can induce an unbending phase transition in addition to unbinding. Both first-order and second-order unbending transitions can occur at and out of coexistence. Results for systems with short-ranged and long-ranged forces establish that the unbending critical point is characterized by hyperuniversal scaling behavior. We show that, at bulk coexistence, the adsorption at the unbending critical point is a universal multiple of the adsorption for the correspondent planar system.

Immune modulation induced by tuberculosis DNA vaccine protects non-obese diabetic mice from diabetes progression

We have described previously the prophylactic and therapeutic effect of a DNA vaccine encoding the Mycobacterium leprae 65 kDa heat shock protein (DNA-HSP65) in experimental murine tuberculosis. However, the high homology of this protein to the corresponding mammalian 60 kDa heat shock protein (Hsp60), together with the CpG motifs in the plasmid vector, could trigger or exacerbate the development of autoimmune diseases. The non-obese diabetic (NOD) mouse develops insulin-dependent diabetes mellitus (IDDM) spontaneously as a consequence of an autoimmune process that leads to destruction of the insulin-producing beta cells of the pancreas. IDDM is characterized by increased T helper 1 (Th1) cell responses toward several autoantigens, including Hsp60, glutamic acid decarboxylase and insulin. In the present study, we evaluated the potential of DNA-HSP65 injection to modulate diabetes in NOD mice. Our results show that DNA-HSP65 or DNA empty vector had no diabetogenic effect and actually protected NOD mice against the development of severe diabetes. However, this effect was more pronounced in DNA-HSP65-injected mice. The protective effect of DNA-HSP65 injection was associated with a clear shift in the cellular infiltration pattern in the pancreas. This change included reduction of CD4(+) and CD8(+) T cells infiltration, appearance of CD25(+) cells influx and an increased staining for interleukin (IL)-10 in the islets. These results show that DNA-HSP65 can protect NOD mice against diabetes and can therefore be considered in the development of new immunotherapeutic strategies.

Immune complex glomerulonephritis in experimental kala-azar. II: Detection and characterization of parasite antigens and antibodies eluted from kidneys of Leishmania donovani-infected hamsters

In a previous report analysing kidney sections by immunofluorescence we showed that hamsters infected with L. donovani develop a glomerulonephritis (GN) associated with deposition of hamster immunoglobulins and parasite antigens in the glomeruli. In this study we characterize these immune components eluted from the kidneys. The eluted immunoglobulins showed specificity for L. donovani antigens and hamster immunoglobulins (rheumatoid factor-like activity). The four isotypes IgG1, IgG2, IgA and IgM were detected. Several L. donovani antigens were detected in the renal eluates by Western blot and immunoprecipitation using 125I-labelled eluates. Proteins with mol. wt of 134, 82, 52, 31, and 26 kD were detected by Western blot and proteins with 134, 110, 93, 89 and 48 kD were detected by immunoprecipitation. With the exception of the 134 kD protein which was recognized by both rabbit anti-promastigote and rabbit anti-amastigote sera all the others were recognized only by the anti-amastigote serum. The 134 kD protein was the only one isolated from the kidneys of infected hamster immunocomplexed with IgG and was the only one detected in a promastigote lysate using IgG from L. donovani-infected hamsters.

Isolation of diterpenes from Araucaria sp Brazilian brown propolis and development of a validated high-performance liquid chromatography method for its analysis

Propolis comprises a complex resinous product composed of plant's parts or exudates, pollen, bee wax, and enzymes. Brazilian brown propolis from Araucaria sp displays several biological activities. Considering the lack of validated analytical methods for its analysis, we are reporting the development of a validated high-performance liquid chromatography with photodiode array detector method to analyze Araucaria brown propolis. The crude propolis were extracted and chromatographed, furnishing six main diterpenes. The isolated standards were used to draw the analytical curves, allowing the studies of selectivity, precision, accuracy, recovery, robustness, the determination of limits of detection and limits of quantification. The mobile phase consisted of 0.1% acetic acid in water and acetonitrile, using an octadecylsilane column, 1 mL/min flow rate and detection at 200 or 241 nm. Relative standard deviation values obtained for intra-day and inter-day precision were lower than 4% for all diterpenes. From the five parameters for robustness, wavelength detection and flow rate were the critical ones. Limits of detection and quantification ranged from 0.808 to 10.359 μg/mL and from 2.448 to 31.392 μg/mL, respectively. The recoveries were between 105.03 and 108.13%, with relative standard deviation values around 5.0%. The developed method is precise, sensitive, and reliable for analyzing Araucaria brown propolis.

Cytotoxic T cells and mycobacteria

How the immune system kills Mycobacterium tuberculosis is still a puzzle. The classical picture of killing due to phagocytosis by activated macrophages may be only partly correct. Based on recent evidence, we express here the view that cytotoxic T lymphocytes also make an important contribution and suggest that DNA vaccines might be a good way to enhance this.

Experimental autoimmune encephalomyelitis evolution was not modified by multiple infections with Strongyloides venezuelensis

According to the hygiene hypothesis, the increased incidence of allergic and autoimmune diseases in developed countries is mainly explained by the decreased contact between the human population and certain environmental agents as lactobacillus, mycobacteria and helminths. In this study, we evaluated the effect of multiple infections with Strongyloides venezuelensis on the development of experimental autoimmune encephalomyelitis (EAE) in Lewis rats. Multiple infections before EAE induction were not able to change the evolution of the disease. No alterations were observed in weight loss, clinical score and inflammation intensity at the central nervous system. The presence of significant levels of parasite-specific IgG1 but not IgG2b suggested a Th2 polarization. However, the percentage and absolute number of CD4+CD25+Foxp3+ T cells were not changed, being their levels in the spleen and lymph nodes of infected rats comparable to the ones found in normal animals. These results suggest that a Th2-polarized response without concomitant expansion of Foxp3+ regulatory T cells was not able to modify EAE progression. Even though these results do not threaten the hygiene hypothesis, they suggest that this paradigm might be an oversimplification. They also emphasize the need of a study to compare the immunoregulatory ability associated with different helminth spp.

Laparoscopic total mesorectal excision for rectal cancer: experience of a single center with a series of 174 patients

BACKGROUND

Laparoscopic total mesorectal excision for low rectal cancer is not considered a gold standard treatment due to the high conversion rate and the long operation time.

METHODS

A retrospective review examined a surgical series of 174 laparoscopic low rectal resections involving total mesorectal excision (1995-2006), with particular reference to technical points as well as surgical and oncologic outcomes. Miles operations and partial mesorectal excisions were excluded.

RESULTS

The cancer affected the low rectum in 110 cases and the medium rectum in 64 cases. A total of 68 patients were subjected to neoadjuvant radiochemotherapy. The anastomosis was mechanical for 83.3% of the cases and intersphinteric through the perineum for 16.6% of the cases. Protective ileostomy was performed in 112 cases. The conversion rate was 4.6%. The mesorectum remained intact in 91.6% of the cases and was partially interrupted in 15 of the cases. In no case was it totally discontinued. The postoperative morbidity rate was 16.7%, and the mortality rate was 0.57%. The incidence of anastomotic fistulas was 14.4%. The percentage was higher for males (18.6 vs 8.3%) and correlated with the low distance of the tumor from the anal verge (18.2 vs 7.8%) and the absence of a protection ileostomy (20.9 vs 10.7%). After an average follow-up period of 48.6 months (range, 24-149 months), six patients (3.44%) experienced a pelvic recurrence. The 5-year overall survival rate was 75.4%, and the disease-free survival rate was 61.9%.

CONCLUSION

Laparoscopic total mesorectal excision for low rectal cancer is safe and effective, allowing surgical and oncologic outcomes similar to those reported for open surgery.

Recovery from Strongyloides venezuelensis infection in Lewis rats is associated with a strong Th2 response

In this study, we investigated the characteristics of the infection and subsequent immunity induced by Strongyloides venezuelensis in Lewis rats. Animals were infected with 4000 L3 of S. venezuelensis and number of eggs per gram of faeces indicated an acute phase around day 8 and a recovery phase around day 32 after infection. A strong Th2 polarization during recovery phase was ascertained by a significant increase in IgG1 and IgE compared with that in the acute period. A shift in the cytokine profile confirmed these findings. A predominant production of IFN-gamma during the acute phase was followed by IL-10 production during recovery. Together these findings show that experimental infection of Lewis rats with S. venezuelensis presents a kinetics of parasite establishment and immunity similar to that described in other models of helminthic infection.

Bacille Calmette-Guérin/DNAhsp65 prime-boost is protective against diabetes in non-obese diabetic mice but not in the streptozotocin model of type 1 diabetes

Type I diabetes is a disease caused by autoimmune destruction of the beta cells in the pancreas that leads to a deficiency in insulin production. The aim of this study was to evaluate the prophylactic potential of a prime-boost strategy involving bacille Calmette-Guérin (BCG) and the pVAXhsp65 vaccine (BCG/DNAhsp65) in diabetes induced by streptozotocin (STZ) in C57BL/6 mice and also in spontaneous type 1 diabetes in non-obese diabetic (NOD) mice. BCG/DNAhsp65 vaccination in NOD mice determined weight gain, protection against hyperglycaemia, decreased islet inflammation, higher levels of cytokine production by the spleen and a reduced number of regulatory T cells in the spleen compared with non-immunized NOD mice. In the STZ model, however, there was no significant difference in the clinical parameters. Although this vaccination strategy did not protect mice in the STZ model, it was very effective in NOD mice. This is the first report demonstrating that a prime-boost strategy could be explored as an immunomodulatory procedure in autoimmune diseases.

Psychological and emotional development, intellectual capabilities, and body image in short normal children

It is well established that children with short stature frequently have problems in cognitive development, personality, self-esteem and social relations. This is partly due to the fact that many parents view them as more vulnerable than other children of normal stature and do not allow them to face the normal experiences that correspond to their actual age. The aim of the present study was to assess, through the administration of appropriate psychological tools, a series of psychological and cognitive characteristics [i.e. anxiety, depression, good adjustment, social functioning, feeling of guilt, interpersonal relationship, intelligence quotient (IQ)], as well as variables linked to development of body image, in a group of children suffering from normal growth variants [familial short stature (FSS), no. 10, 4 males/6 females; with constitutional growth delay (CGD), no. 4,4 males; height standard deviation score (HSDS) ranging between -2.4 and -1.9] and in a control group children of normal stature (HSDS between -0.1 and +0.1). Children with short stature significantly differed from normal statured controls as far as Colored Progressive Matrices (CPMs, centiles), IQ (IQ, obtained using the Goodenough test), "Good Adjustment" (Draw-a-Person index, DAP), "Feelings of Guilt" (DAP index), "Height" (as emerges from drawings of the body) are concerned. Significant relationships were found between the height of the subjects (in centiles) and cognitive skills, measured both using CPMs (r=0.408; p=0.017) and Draw-a-Man (DAM) (r=0.359; p=0.037) and between height and feelings of guilt (r=0.325; p=0.027), measured using DAP. CPM scores correlated positively with the "Good Adjustment" index of DAP (r=0.354; p=0.05) and negatively with Children's Depression Inventory (CDI) (r=-0.609; p=0.01), "School Anxiety" index (r=-0.427; p=0.05) and "Total Anxiety" index (r=-0.436; p=0.05) of the Anxiety Scale Questionnaire for the Age of Development, and with 2 indices of DAP, namely, "Feelings of Guilt" (r=-0.461; p=0.01) and "Interpersonal Relationships (Difficulty in Establishing)" (r=-0.455; p=0.01). A significant positive correlation was found between the height of the subject and both the measurement of the "Body of Drawing 3" (r=0.450, p=0.01) and the measurement of the "Body of Drawing 4" (r=0.461, p=0.01), as well as the with the "Total Height of Drawing 4" (r=0.464, p=0.01). Higher indices for anxiety, depression, feelings of guilt and difficulty in establishing interpersonal relationships and lower indices for good adjustment were found in children with CGD as compared to subjects with FSS or normal statured children. Although further additional studies on larger samples are needed to confirm these preliminary observations, the present study underlines the importance of psychological support also during the growth and development in short normal children.

Should enhanced recovery after surgery (ERAS) pathways be preferred over standard practice for patients undergoing abdominal wall reconstruction? A systematic review and meta-analysis

PURPOSE

Although many studies assessing enhanced recovery after surgery (ERAS) pathways in abdominal wall reconstruction (AWR) have recently demonstrated lower rates of postoperative morbidity and a decrease in postoperative length of stay compared to standard practice, the utility of ERAS in AWR remains largely unknown.

METHODS

A systematic literature search for randomized and non-randomized studies comparing ERAS (ERAS +) pathways and standard protocols (Control) as an adopted practice for patients undergoing AWR was performed using MEDLINE, the Cochrane Central Register of Controlled Trials, Scopus, Web of Science, and EMBASE databases. A predefined search strategy was implemented. The included studies were reviewed for primary outcomes: overall postoperative morbidity, abdominal wall morbidity, surgical site infection (SSI), and length of hospital stay; and for secondary outcome: operative time, estimated blood loss, time to discontinuation of narcotics, time to urinary catheter removal, time to return to bowel function, time to return to regular diet, and readmission rate. Standardized mean difference (SMD) was calculated for continuous variables and Odds Ratio for dichotomous variables.

RESULTS

Five non-randomized studies were included for qualitative and quantitative synthesis. 840 patients were allocated to either ERAS + (382) or Control (458). ERAS + and Control groups showed equivalent results with regard to the incidence of postoperative morbidity (OR 0.73, 95% CI 0.32-1.63; I2= 76%), SSI (OR 1.17, 95% CI 0.43-3.22; I2= 54%), time to return to bowel function (SMD - 2.57, 95% CI - 5.32 to 0.17; I2= 99%), time to discontinuation of narcotics (SMD - 0.61, 95% CI - 1.81 to 0.59; I2= 97%), time to urinary catheter removal (SMD - 2.77, 95% CI - 6.05 to 0.51; I2= 99%), time to return to regular diet (SMD - 0.77, 95% CI - 2.29 to 0.74; I2= 98%), and readmission rate (OR 0.82, 95% CI 0.52-1.27; I2= 49%). Length of hospital stay was significantly shorter in the ERAS + compared to the Control group (SMD - 0.93, 95% CI - 1.84 to - 0.02; I2= 97%).

CONCLUSIONS

The introduction of an ERAS pathway into the clinical practice for patients undergoing AWR may cause a decreased length of hospitalization. These results should be interpreted with caution, due to the low level of evidence and the high heterogeneity.

Laparoscopic approach in emergency for the treatment of acute incarcerated groin hernia: a systematic review and meta-analysis

PURPOSE

Minimally invasive approach for acute incarcerated groin hernia repair is still debated. To clarify this debate, a literature review was performed.

METHODS

Search was performed in PubMed, Embase, Scopus, Web of Science, and Cochrane databases, founding 28,183 articles.

RESULTS

Fifteen articles, and 433 patients were included (16 bilateral hernia, range 3-8). Three hundred and eighty-eight (75.3%) and 103 patients (22.9%) underwent transabdominal preperitoneal and totally extraperitoneal repair, respectively, and in 5 patients, the defect was buttressed with broad ligament (1.1%) (not specified in 3 patients). Herniated structures were resected in 48 cases (range 1-9). Intraoperative complications and conversion occurred in 4 (range 0-1) and 10 (range 0-3) patients, respectively. Mean operative time and hospital stay ranged between 50 and 147 min, and 2 and 7 days, respectively. Postoperative complications ranged between 1 and 19. Five studies compared laparoscopic and open approaches (163 and 235 patients). Herniated structures were resected in 19 (11.7%) and 42 cases (17.9%) for laparoscopic and open approach, respectively (p = 0.1191). Intraoperative complications and conversion occurred in one (0.6%) and 5 (2.1%) patients (p = 0.4077), and in two (1.2%) and 19 (8.1%) patients (p = 0.0023), in case of laparoscopic or open approach, respectively. Mean operative time and hospital stay were 94.4 ± 40.2 and 102.8 ± 43.7 min, and 4.8 ± 2.2 and 11 ± 3.1 days, in laparoscopic or open approach, respectively. Sixteen (9.8%) and 57 (24.3%) postoperative complications occurred.

CONCLUSION

Laparoscopy seems to be a safe and feasible approach for the treatment of acute incarcerated groin hernia. Further studies are required for definitive conclusions.

Down-modulation of lymphoproliferation and interferon-gamma production by beta-glucan derived from Saccharomyces cerevisiae

beta-glucan, one of the major cell wall components of Saccharomyces cerevisiae, has been found to enhance immune functions. This study investigated in vivo and in vitro effects of beta-glucan on lymphoproliferation and interferon-gamma (IFN-gamma) production by splenic cells from C57BL/6 female mice. All experiments were performed with particulate beta-glucan derived from S. cerevisiae. Data demonstrated that both, i.p. administration of particulate beta-glucan (20 or 100 micrograms/animal) and in vitro stimulation of splenic cells (20 or 100 micrograms/ml of culture) decreased lymphoproliferation and IFN-gamma production induced by concanavalin A. These results suggest that beta-glucan can trigger a down-modulatory effect regulating a deleterious immune system hyperactivity in the presence of a strong stimulus.

Application of computed tomography to assess the effect of egg yolk ratio on body composition in chickens of different genotype and gender at hatch and during the rearing period

1. Computed tomography was used for the in vivo determination of yolk ratio in 7000 domestic hen eggs, originated from two markedly different genotypes, in order to examine the effect of egg yolk ratio, gender and genotype on the development of hatched chicks. 2. Eggs with extremely low, average and extremely high yolk ratio were chosen for further investigation (n = 350 in each group in both genotypes). After incubating the selected eggs, hatched birds were reared and slaughtered at 11 weeks of age. 3. The yolk ratio of eggs significantly affected the body composition of the chickens at hatching and during rearing to 8-9 weeks of age. 4. Chickens of a genotype selected partly for weight gain had significantly higher live weight from hatching to the end of the rearing period and had better slaughter characteristics than those of the dual purpose TETRA-H genotype. 5. At hatching, only the dry matter content of the body was affected by the gender of the birds. The effect of gender on the live weight and body composition of chickens was evident from the 5th week of age to the time of slaughter. 6. It was concluded that eggs with a low yolk ratio were most beneficial for broiler production, because chickens hatched from these eggs had the highest slaughter weight and muscle index and the lowest fat index for their body mass.

Contribution of CT to treatment planning in patients with GIST

PURPOSE

The aim of this study was to illustrate the morphological and structural computed tomography (CT) patterns of gastrointestinal stromal tumours (GIST) and to discuss the technique's role in identifying lesions at a higher risk for malignant potential, in treatment planning and in the follow-up of patients with GIST.

MATERIALS AND METHODS

We retrospectively reviewed the CT scans of 26 patients who underwent surgery for histologically confirmed GIST of the stomach (20 cases), the duodenum (1), the caecum (1), the small bowel (2), the descending colon (1) and the rectum (1). CT exams were performed with a single-slice scanner and a 5-mm collimation before and after the intravenous administration of contrast material.

RESULTS

CT allowed us to correctly define the site, size and structure of lesions in all cases and to identify signs of invasion of neighbouring structures in some cases. The lesions exhibited solid density on the unenhanced scan and poor enhancement after contrast-medium administration; lesion structure was homogeneous in ten cases and inhomogeneous in 16; in one case, histology revealed microcalcification that had not been detected by CT.

CONCLUSIONS

CT, with its panoramic capabilities and high contrast resolution, provides essential information for treatment planning and for the follow-up of GIST patients treated with surgery or chemotherapy.

Neonatal BCG immunization followed by DNAhsp65 boosters: highly immunogenic but not protective against tuberculosis - a paradoxical effect of the vector?

A new tuberculosis vaccine is urgently needed. Prime-boost strategies are considered very promising and the inclusion of BCG is highly desirable. In this investigation, we tested the protective efficacy of BCG delivered in the neonatal period followed by boosters in the adult phase with a DNA vaccine containing the hsp65 gene from Mycobacterium leprae (pVAXhsp65). Immune responses were characterized by serum anti-hsp65 antibody levels and IFN-gamma and IL-5 production by the spleen. Amounts of these cytokines were also determined in lung homogenates. Protective efficacy was established by the number of colony-forming units (CFU) and histopathological analysis of the lungs after challenge with Mycobacterium tuberculosis. Immunization with BCG alone triggered a significant reduction of CFU in the lungs and also clearly preserved the pulmonary parenchyma. BCG priming also increased the immunogenicity of pVAXhsp65. However, boosters with pVAXhsp65 or the empty vector abolished the protective efficacy of BCG. Also, higher IL-5 levels were produced by spleen and lungs after DNA boosters. These results demonstrated that neonatal BCG immunization followed by DNAhsp65 boosters is highly immunogenic but is not protective against tuberculosis.