Rapamycin-based graft-versus-host disease prophylaxis increases the immunosuppressivity of myeloid-derived suppressor cells without affecting T cells and anti-tumor cytotoxicity

The immunosuppressant rapamycin (RAPA) inhibits mammalian target of rapamycin (mTOR) functions and is applied after allogeneic bone marrow transplantation (BMT) to attenuate the development of graft‐versus‐host disease (GVHD), although the cellular targets of RAPA treatment are not well defined. Allogeneic T cells are the main drivers of GVHD, while immunoregulatory myeloid‐derived suppressor cells (MDSCs) were recently identified as potent disease inhibitors. In this study, we analyzed whether RAPA prevents the deleterious effects of allogeneic T cells or supports the immunosuppressive functions of MDSCs in a BMT model with major histocompatibility complex (MHC) classes I and II disparities. RAPA treatment efficiently attenuated clinical and histological GVHD and strongly decreased disease‐induced mortality. Although splenocyte numbers increased during RAPA treatment, the ratio of effector T cells to MDSCs was unaltered. However, RAPA treatment induced massive changes in the genomic landscape of MDSCs preferentially up‐regulating genes responsible for uptake or signal transduction of lipopeptides and lipoproteins. Most importantly, MDSCs from RAPA‐treated mice exhibited increased immunosuppressive potential, which was primarily inducible nitric oxide synthase (iNOS)‐dependent. Surprisingly, RAPA treatment had no impact on the genomic landscape of T cells, which was reflected by unchanged expression of activation and exhaustion markers and cytokine profiles in T cells from RAPA‐treated and untreated mice. Similarly, T cell cytotoxicity and the graft‐versus‐tumor effect were maintained as co‐transplanted tumor cells were efficiently eradicated, indicating that the immunosuppressant RAPA might be an attractive approach to strengthen the immunosuppressive function of MDSCs without affecting T cell immunity.

The tell-tale thigh

A body of a 91-year-old donor underwent whole-body CT scanning before being transferred for use in an anatomical dissection course. Metallic objects were detected in the thigh muscles, extensive bone abnormalities were found in the left femur and the diaphysis of the left femur was 50% wider than that of the right diaphysis. History revealed that the body donor had been seriously wounded at the end of World War II by a rocket explosion. His multiple fractures and lesions had not been surgically treated either in an Austrian military hospital or in a French prisoner of war camp. The patient suffered for almost 70 years from this violation of the Geneva Conventions. In the light of current armed conflicts, the present case is an example of how one injustice can result in severe, lifelong medical consequences. It also shows that the history behind a wounded thigh can have an enormous impact on teaching ethics to today's medical students.

[Effectiveness of Haemophilus influenzae B-diphtheria conjugate vaccination in German children]

BACKGROUND

In 1990 the Haemophilus influenzae b-Diphtheria conjugate vaccine (Hib-D) was introduced in Germany. In addition, most children under 18 months of age failed to develop protective levels of Hib antibodies in response to systemic infections.

METHODS

To evaluate the protective efficacy of the Hib-D vaccine in Germany a post marketing case-control study was performed during 1.5. 1990-30.4. 1992. Surveillance for invasive Hib-infections was maintained by pediatricians of 8 hospitals in the Rhein-Main area. The antibody responses to Hib were evaluated by ELISA at the onset (days 0-3) and during remission of disease.

RESULTS

During the first year of the study 23 cases per 100,000 children of invasive Hib-infections were recorded. Of these children, 15 suffered from meningitis, 6 from epiglottitis and one from cellulitis and pericarditis respectively. None of these patients had been vaccinated except for one, who received two injections of Hib-D. Due to increased acceptance of the Hib-D vaccine we found a significant reduction of invasive Hib-infections (6 cases per 100,000 children) in the second year of the study. Again, of these children only one child was vaccinated. As expected, in all patients investigated the initial Hib antibody level was below 1 microgram/ml. The development of Hib specific immunity to invasive disease was clearly age dependent: 10 of 11 children below 18 months failed to produce any Hib antibodies (> 0.15 microgram/ml) in response to their infection. In contrast 8 of 10 children older than 18 months developed protective antibody levels to Hib.

CONCLUSIONS

The incidence of serious Hib-disease has significantly decreased in Germany since the introduction of the Hib-D vaccine. Because no other Hib vaccine was licensed in Germany our data confirm efficacy and safety of Hib-D reported previously. In addition, children, who contracted disease before 18 months of age, remain susceptible to Hib and require active immunization for protection.

Solid-phase extraction of drugs from biological tissues--a review

Solid-phase extraction procedures are being used increasingly in all types of drug testing laboratories, including those which carry out forensic toxicology. The advantages of such procedures include decreased operator time, reduced solvent volumes, and increased extraction efficiency. The application of existing techniques, however, has not yet been applied to tissues that are widely available postmortem. Tissue analysis can make the task of interpretation of drug levels much easier, particularly where unstable drugs are involved (e.g., cocaine). This review article explores the possibilities of applying existing extraction procedures to human tissue samples. We also consider the reasons why forensic laboratories have been slow to investigate such possibilities. We hope to stimulate interest in alternative tissue extraction procedures by reviewing reported procedures that apply to both human and animal tissue.

A rapid method for the determination of cocaine in brain tissue

A rapid procedure is described for the extraction and analysis of brain samples for cocaine and benzoylecgonine. Human brain tissue was sectioned at autopsy, and samples were subjected to a lipase digestion, subsequent to solid-phase extraction. The distribution of cocaine and benzoylecgonine throughout different regions of the brain was determined by high-performance liquid chromatography.

The concept of the neuroleptic threshold: an update

The authors review the development and the controversies of the neuroleptic threshold theory. According to this theory, the minimum effective antipsychotic dose of a neuroleptic ("threshold dose") correlates with the appearance of "fine motor" symptoms (micrography) as opposed to the appearance of manifest or "coarse motor" extrapyramidal side effects. About half of the acutely exacerbated schizophrenic patients respond to threshold doses, but no predictors are known to characterize the responders. The neuroleptic threshold doses were found to be low, and the low dose treatment strategy is supported by the results of current PET and neuroleptic plasma level studies.

[Correlation between immuno-morphological parameters of regional lymph nodes and the mortality of patients with stage I and II bronchial squamos cell carcinoma]

Histological changes in tracheobronchial and bronchopulmonary lymph nodes of patients with operable (i.e. stages T 0/2, N 0/1, M0) bronchogenic squamous cell carcinoma were examined histometrically. Out of 29 patients 10 survived less than 12 months and 19 lived longer than two years after surgery. Quantitive methods were employed for measuring structural changes in lymph node sections at the histological and cellular level. The following parameters reflecting both cellular and humoral immune responses correlated with survival: relative numbers of large lymphoid cells and mitotic figures in the paracortical "thymus dependent") area; volume of the follicular (predominantly B-cell) cortex and volume of germinal centers. Pronounced accumulation of histiocytes or dust-loaded marcrophages in the paracortex and presence of "empty" lymph sinusoids (i.e. without sinushistiocytosis) correlated inversely with survival. Besides the theoretical importance and considerations of a documented immune response, such data could help in identifying high risk groups within the same stage of bronchogenic carcinoma of a given type.

Immunomorphological lymph node changes in patients with operable bronchogenic squamous cell carcinoma

Histological changes in tracheobronchial and bronchopulmonary lymph nodes of patients with operable (i.e. stages T1/2, N0/1, M0) bronchogenic squamous cell carcinoma were examined histometrically. Out of 29 patients, 10 survived less than 12 months and 19 lived longer than two years after surgery. Quantitative methods were employed for measuring structural changes in lymph node sections at the histological and cellular level. The following parameters reflecting both cellular and humoral immune responses correlated with survival: relative numbers of large lymphoid cells and mitotic figures in the paracortical ("thymus-dependent") area; volume of the follicular (predominantly B-cell) cortex; and volume of germinal centers. Pronounced accumulation of histiocytes or dust-loaded macrophages in the paracortex and presence of "empty" lymph sinusoids (i.e. without sinuhistiocytosis) correlated inversely with survival. In addition to the theoretical importance and considerations of a documented immune response, such data could help in identifying high risk groups within the same stage of bronchogenic carcinoma of a given type.