Postoperative transverse sternal nonunion with a chest wall defect managed by a tibial locking plate and a Gore-Tex dual mesh membrane: a case report

Background

Transverse sternal nonunion is a rare but disabling complication of chest trauma or a transverse sternotomy. Fixation methods, mainly used to manage the more common longitudinal sternal nonunion, often fail, leaving the surgical treatment of transverse nonunion to be a challenge.

Case presentation

We present a case of a highly-disabling, postoperative chest wall defect resulting from transverse sternal nonunion after a transverse thoracosternotomy (clamshell incision) and a concomitant rib resection. Following unsuccessful surgical attempts, the sternal nonunion was fixed with a tibial locking plate and bone grafted, while the post-rib resection chest defect was reconstructed with a Gore-Tex dual mesh membrane. Adequate chest stability was achieved, enabling complete healing of the sternal nonunion and the patient’s complete recovery.

Conclusion

We believe it is important to address both in the rare case of combined postoperative transverse sternal nonunion and the chest wall defect after rib resection. A good outcome was achieved in our patient by fixing the nonunion with an appropriately sized and shaped locking plate with bone grafting and covering the chest defect with a dual mesh membrane.

Influence of conjugated linoleic acid on the porcine immune response and morbidity: a randomized controlled trial

Background

Conjugated linoleic acid (CLA) has diverse influences on the immune response in different experimental models. In the present study we investigated the effect of CLA feeding on inflammatory and immune responses in a piglet model. We studied the duration of this effect and possible detrimental effects of CLA feeding. After 12 weeks of CLA and control supplementation and washout, animals were sacrificed and parenchymal organs were histologically examined.

Results

In activated peripheral mononuclear cells interferon-γ was significantly (p = 0.008) lower in the CLA group by the end of the feeding period. This effect disappeared as soon as supplementation was stopped. No differences were found in the tumour necrosis factor-α, interleukin-10 production, serum immunoglobulin-G levels and fat infiltration of the liver, except that fat storage cell infiltration was significantly (p < 0.04) higher in the CLA-fed group. The effect of time for interferon-γ, interleukin-10 and immunoglobulin-G levels was statistically significant.

Conclusion

At the end of the feeding period the interferon-γ response was depressed. However, the maturation of the piglet immune system in our young pig model probably outweighs the impact of CLA feeding on the immune response, even though liver fat storage cell infiltration, which plays an important role in liver regeneration, increased during CLA feeding of the piglets.

Conversion of Borrelia garinii cystic forms to motile spirochetes in vivo

Cystic forms (also called spheroplasts or starvation forms) and their ability to reconvert into normal motile spirochetes have already been demonstrated in the Borrelia burgdorferi sensu lato complex. The aim of this study was to determine whether motile B. garinii could develop from cystic forms, not only in vitro but also in vivo, in cyst-inoculated mice. The cysts prepared in distilled water were able to reconvert into normal motile spirochetes at any time during in vitro experiments, lasting one month, even after freeze-thawing of the cysts. Motile spirochetes were successfully isolated from 2 out of 15 mice inoculated intraperitoneally with cystic forms, showing the infectivity of the cysts. The demonstrated capacity of the cysts to reconvert into motile spirochetes in vivo and their surprising resistance to adverse environmental conditions should lead to further studies on the role and function of these forms in Lyme disease.

Cell-mediated immune response to high-passage Borrelia spirochetes in C57bl/6 mice is strictly dependent on antigen specificity

Inbred C57bl/6 mice were challenged with high-passage Borrelia afzelii, Borrelia garinii and Borrelia burgdorferi sensu stricto and tested for antigen specific T-cell response in vitro. Sonicated preparations of washed spirochetes were potent cell activators, capable of stimulating polyclonal proliferation after 72h of culture while increasing the incubation time up to 120h provoked specific cell-mediated response. Isolated murine spleocytes previously sensitized to B. burgdorferi sensu lato but not those from control mice could be induced for antigen-specific proliferation in vitro, as revealed by [3H]thymidine incorporation assay, Moreover, in mice presensitized to B. burgdorferi sensu lato, detectable cell-mediated response could be induced only with antigen preparations derived from a corresponding strain but not with those obtained from other Borrelia genospecies. The current study emphasises that the B. burgdorferi antigen-specific response may also be expected in different genospecies infections in men.

Murine monoclonal antibodies directed against human recombinant Macrophage Migration Inhibitory Factor

Macrophage Migration Inhibitory Factor (MIF) is a crucial component of the immune system acting together with glucocorticosteroids to regulate immunity and inflammation. Understanding of its many putative functions and action mechanisms is still ambiguous. Due to the newest findings that a local MIF expression is up regulated in allograft rejection and in glomerulonephritis, an interest in MIF research is increasing and is focused on possibilities of anti-MIF treatment. In the present work new murine monoclonal antibodies (MAbs) directed against human recombinant MIF (hrMIF) are described. hrMIF protein used for the immunisation was tested for its biological activity and has evident macrophage migration inhibitory activity. The selected MAbs were purified and further characterised. They recognised MIF in a Western blot experiment after a native IEF. Anti-MIF MAb designated as M1 inhibited MIF activity in the test, which was performed in the 48 well Boyden chamber system. It is presumed that M1 MAb could be used as a potential therapeutic agent.

Human peripheral blood lymphocytes sensitised to PPD respond to in vitro stimulation with increased expression of CD69 and CD134 activation antigens and production of Th-1 type cytokines

Individuals sensitised to Mycobacterium tuberculosis antigens by infection, vaccination or Mantoux test generate specific memory cells. The response to in vitro restimulation with PPD is observed as the lymphoid cell proliferation and production of Th-1 type cytokines. Cell-mediated immune response was measured by Mantoux test, lymphocyte blast transformation test, estimation of IFN-gamma production (Quantiferon, ELISPOT), and expression of CD69 and CD134 molecules on the T-helper lymphocytes (CD4+). All the methods used were compared for parity of the results. According to Mantoux test results, the patients could be distributed into two groups: responder and non-responder group. Induration in Mantoux test after a new contact with PPD in non-responders was smaller than 5 mm, they produced only small amounts of IFN-gamma, lymphocyte blast transformation was poor, and expression of CD69 and CD134 was low. In responders reaction was much more intensive in all tests measured. We conclude that the reactivity of memory cells to M. tuberculosis antigens can be effectively detected by Mantoux test. The same was true also for the in vitro tests presented but in addition the in vitro tests give more information about the mechanism involved in the immune response against M. tuberculosis.

A mouse model of chronic bacterial lesions (a cotton trap) for studying oral bacteria-lymphocyte interactions

We established a mouse model of chronic bacterial infection (cotton trap) to get a deeper insight into interactions between immune cells and bacterial strains, that are most commonly isolated from periapical processes. We have used flow cytometry to identify the presence of intracellular cytokines of activated T cells collected from cotton traps, previously infected with different strains of bacteria and implanted subcutaneously into the back of the mice. We provide an evidence that anaerobic bacteria (Bacteroides sp.) and nocardiae are more effective in inducing cytotoxic immunity and Th1 response compared to oral streptococci. Differences in immune response against anaerobic bacteria when compared to streptococci are probably dependent on some non-specific immune cell stimulation (e.g. by bacterial cell wall components), nevertheless the role of specific antigen-dependent immune mechanism can not be excluded.

Immune response in lymphocyte cultures stimulated by oral bacteria preparations

Lymphocyte cultures were used as an in vitro experimental model to get a deeper insight into immune response to oral bacteria in periapical granulomas. Lymphocytes isolated from leucocyte concentrate were in lymphocyte cultures stimulated by antigen preparations of oral bacteria. Lymphocyte subsets that have developed in lymphocyte cultures after a week of stimulation were analysed by flow cytometry. A significant increase in expression of INF-gamma molecules in CD3+ cells stimulated by antigen preparations of oral streptococci was found, compared with negative control. On the other hand we observed a significant increase in expression of IL-4 in CD3+ cells stimulated by antigens of anaerobic bacteria, compared with negative control. Our results show that antigens of oral streptococci in in vitro lymphocyte cultures induce the differentiation of T helper cells into Th2 cells and that antigen preparations of anaerobic bacteria induce the differentiation of T helper cells into Th1 cells. Furthermore, an increased expression of HLA-DR molecules on CD8+ T cells stimulated by antigens of oral streptococci was found, compared with negative control.

The cell-mediated immune response to Borrelia afzelii, garinii and burgdorferi in C57BL/6 mice is dependent on antigen specificity

Inbred C57BL/6 mice were challenged with Borrelia afzelii, Borrelia garinii and Borrelia burgdorferi sensu stricto and tested for antigen-specific T-cell response in vitro. The sonicated preparations of in vitro grown spirochetes were capable of stimulating polyclonal proliferation and specific cell-mediated response, depending on duration of the cell culture. Murine splenocytes previously sensitized to B. burgdorferi sensu lato (s.l. ), but not those from control mice, could be induced for antigen-specific proliferation in vitro. Moreover, detectable cell-mediated response could be induced only with antigen preparations derived from a corresponding strain but not with those obtained from other Borrelia genospecies as revealed by the [(3)H]thymidine incorporation assay. The current study considers that the strict B. burgdorferi s.l. antigen-specific response may also be expected in infections in humans and contributes to the explanation of the frequently poor antibody- and cell-mediated immune response observed in patients diagnosed with Lyme disease.

Diminished interferon-gamma production in gastric mucosa T lymphocytes after H. pylori eradication in duodenal ulcer patients

BACKGROUND/AIMS

Helicobacter pylori (H. pylori) infects an estimated 50% of the world population; however, only a small proportion of individuals develop clinical symptoms of gastritis, peptic ulceration or gastric cancer. The variations in disease presentation may be due to differences in bacterial virulence and/or immune response to the pathogen. In a previous study we reported an increased expression of the IL-2 receptor in duodenal ulcer (DU) patients. The present study examines the expression of IL-2 receptor and intracellular lymphokine production in gastric mucosa infiltrating T lymphocytes in DU patients before and after H. pylori eradication.

METHODOLOGY

T lymphocytes were isolated from gastric mucosa biopsies by using mechanical and enzymatic tissue desegregation. Ficoll-purified lymphocytes were incubated with monoclonal antibodies and analyzed by using 4-color flow cytometry analysis for the IL-2 receptor (CD25) and intracellular interferon-gamma (IFN-gamma) and IL-4 expression. Lymphocytes from 24 H. pylori-infected patients with severe gastric mucosa infiltration (G2 and G3 histological type in Sydney classification) were analyzed.

RESULTS

We demonstrated a significant decrease in IL-2 receptor expression on gastric mucosa T cells 3 and 12 months after eradication of H. pylori. We also demonstrated a diminished IFN-gamma production 3 and 12 months after H. pylori eradication.

CONCLUSIONS

Our results suggest that cellular immune activation in gastric mucosa is reversibly dependent on the presence of H. pylori.