Postnatal expansion of mesenteric lymph node stromal cells towards reticular and CD34+ stromal cell subsets

Gut-draining mesenteric lymph nodes (LN) provide the framework to shape intestinal adaptive immune responses. Based on the transcriptional signatures established by our previous work, the composition and immunomodulatory function of LN stromal cells (SC) vary according to location. Here, we describe the single-cell composition and development of the SC compartment within mesenteric LNs derived from postnatal to aged mice. We identify CD34⁺ SC and fibroblastic reticular stromal cell (FRC) progenitors as putative progenitors, both supplying the typical rapid postnatal mesenteric LN expansion. We further establish the location-specific chromatin accessibility and DNA methylation landscape of non-endothelial SCs and identify a microbiota-independent core epigenomic signature, showing characteristic differences between SCs from mesenteric and skin-draining peripheral LNs. The epigenomic landscape of SCs points to dynamic expression of Irf3 along the differentiation trajectories of FRCs. Accordingly, a mesenchymal stem cell line acquires a Cxcl9⁺ FRC molecular phenotype upon lentiviral overexpression of Irf3, and the relevance of Irf3 for SC biology is further underscored by the diminished proportion of Ccl19⁺ and Cxcl9⁺ FRCs in LNs of Irf3^-/- mice. Together, our data constitute a comprehensive transcriptional and epigenomic map of mesenteric LNSC development in early life and dissect location-specific, microbiota-independent properties of non-endothelial SCs.

The microbiota is dispensable for the early stages of peripheral regulatory T cell induction within mesenteric lymph nodes

Intestinal Foxp3+ regulatory T cell (Treg) subsets are crucial players in tolerance to microbiota-derived and food-borne antigens, and compelling evidence suggests that the intestinal microbiota modulates their generation, functional specialization, and maintenance. Selected bacterial species and microbiota-derived metabolites, such as short-chain fatty acids (SCFAs), have been reported to promote Treg homeostasis in the intestinal lamina propria. Furthermore, gut-draining mesenteric lymph nodes (mLNs) are particularly efficient sites for the generation of peripherally induced Tregs (pTregs). Despite this knowledge, the direct role of the microbiota and their metabolites in the early stages of pTreg induction within mLNs is not fully elucidated. Here, using an adoptive transfer-based pTreg induction system, we demonstrate that neither transfer of a dysbiotic microbiota nor dietary SCFA supplementation modulated the pTreg induction capacity of mLNs. Even mice housed under germ-free (GF) conditions displayed equivalent pTreg induction within mLNs. Further molecular characterization of these de novo induced pTregs from mLNs by dissection of their transcriptomes and accessible chromatin regions revealed that the microbiota indeed has a limited impact and does not contribute to the initialization of the Treg-specific epigenetic landscape. Overall, our data suggest that the microbiota is dispensable for the early stages of pTreg induction within mLNs.

F376A/M388A-solulin, a new promising antifibrinolytic for severe haemophilia A

INTRODUCTION

Haemophilia is a major bleeding disorder due to a deficiency of procoagulant factor VIII (type A) or IX (type B). The treatment is substitutive and based on infusion of factor concentrates. Main limitations of this therapy are cost, short factor half-life and the development of inhibitors (up to 30% of severe HA patients). An important aggravating factor of haemophilia is due to a premature fibrinolysis, directing attention to the therapeutic potential of suitable antifibrinolytics. Thrombomodulin (TM) is a key player of the coagulation cascade by activating protein C (an inhibitor of thrombin generation, thus antagonizing coagulation) and of the fibrinolytic cascade by activating thrombin activatable fibrinolysis inhibitor TAFI (thus reducing fibrinolysis). Solulin is a soluble form of TM that shows both capabilities.

AIM

Here, we developed a new generation of solulin variants (F376A-, M388A- and F376A/M388A-solulin) with a decreased ability to activate protein C and a conserved capacity to activate TAFI.

METHODS

We produced and characterized solulin variants in vitro. In addition, F376A/M388A-solulin was tested ex vivo, using blood samples of haemophilic A patients, with thromboelastography.

RESULTS

The solulin variants (F376A, M388A and the double-mutant F376A/M388A) lost their abilities to activate protein C but are still capable to activate TAFI. Thrombelastography showed increased clot firmness and stability, that, as opposed to wild-type solulin, was maintained even at high concentrations of F376A/M388A-solulin (100 nm).

CONCLUSION

In sum, these results open new opportunities for the development of specific medication for haemophilic patients.

Information Needs of Cancer Patients and Perception of Impact of the Disease, of Self-Efficacy, and Locus of Control

The aim of our study was to investigate the relationship between information needs and cancer patients' perceptions of the impact of the disease, self-efficacy, and locus of control. Using a standardized questionnaire, we obtained data from patients who attended a series of lectures. The questionnaire included questions on their information needs, sources of information, satisfaction with information, and short questionnaires on self-efficacy, perception of the disease, and locus of control of reinforcement. Data was obtained from 185 patients. Our results showed that the sources of information that were most often used were physicians (84 %), print media (68 %), and the Internet (59 %); online fora (7.5 %), non-medical practitioners (9.7 %), and telephone-based counseling (8.6 %) were only used by a minority. Patients with a high perception of their own control over the disease more often used any source of information available to them and were more often interested in acquiring additional information. Higher self-efficacy was significantly associated with the need for information on all topics. Patients with a higher external locus of control significantly more often used sources of information and had significantly more need for additional information. By contrast, there were no associations with an internal locus of control. Neither external nor internal locus of control showed any associations with satisfaction with information. Information needs seem to be higher in patients with a high external locus of control and low self-efficacy. Physicians, other professionals, and institutions that provide information may take these relationships into consideration for tailoring their services to patients.

A lecture program on complementary and alternative medicine for cancer patients--evaluation of the pilot phase

About half of all patients with cancer use complementary or alternative medicine (CAM). In 2013, we started a lecture program for patients, followed by evidence-based recommendations on counseling on CAM. These recommendations have been published before by this working group. The aim of the program is to provide scientific facts on the most often used CAM methods in standardized presentations which help patients discuss the topic with their oncologists and support shared decision making. The article presents the evaluation of the pilot phase. Participants received a standardized questionnaire before the start of the lecture. The questionnaire comprises four parts: demographic data, data concerning experience with CAM, satisfaction with the lecture, and needs for further information on CAM. In 2013, seven lectures on CAM were given in cooperation with regional branches of the German Cancer Society in several German states. Four hundred sixty patients and relatives took part (75% females and 16% males). Forty-eight percent formerly had used CAM. Most often named sources of information on CAM were print media (48%) and the Internet (37%). Most participants rated additional written information valuable. About one third would like to have an individual consultation concerning CAM. A standardized presentation of evidence on CAM methods most often used, together with recommendations on the self-management of symptoms, is highly appreciated. The concept of a highly interactive lecture comprising is feasible and if presented in lay terminology, adequate. In order to give additional support on the topic, written information should be provided as the first step.

The adhesion receptor CD155 determines the magnitude of humoral immune responses against orally ingested antigens

CD155, originally known as the cellular receptor for poliovirus, is the founding member of a subfamily of immunoglobulin-like adhesion receptors. Apart from its function in establishing adherens junctions between contacting epithelial cells, the engagement of CD155 with two recently identified ligands, CD226 and CD96, mediates immunologically relevant processes such as NK cell-driven killing of tumor cells in humans. Here we report on the generation and immunological analysis of mice constitutively deficient of CD155. Moreover, the expression profile of CD155 on hematopoietic cells has been determined using newly established antibodies. CD155-deficient mice develop normally without displaying an overt phenotype. However, the animals are distinguished by distinct deficits in the development of a regular humoral immune response. Whereas systemic challenges revealed no differences, orally administered antigen evoked less efficient IgG and IgA antibody responses despite of normal IgM titers when compared to wild-type mice. Therefore, CD155 may assist in an efficient humoral immune response generated within the intestinal immune system.

Comparison of a production process in a membrane-aerated stirred tank and up to 1000-L airlift bioreactors using BHK-21 cells and chemically defined protein-free medium

The applicability of a protein-free medium for the production of recombinant human interleukin-2 with baby hamster kidney cells in airlift bioreactors was investigated. For this purpose, a BHK-21 cell line, adapted to grow and produce in protein-free SMIF7 medium without forming spheroids in membrane-aerated bubble-free bioreactors, was used as the producer cell line. First, cultivation of the cells was established at a 20-L scale using an internal loop airlift bioreactor system. During the culturing process the medium formulation was optimized according to the specific requirements associated with cultivation of mammalian cells under protein-free conditions in a bubble-aerated system. The effects of the addition of an antifoam agent on growth, viability, productivity, metabolic rates, and release of lactate dehydrogenase were investigated. Although it was possible to establish cultivation and production at a 20-L scale without the use of antifoaming substances, the addition of 0.002% silicon-oil-based antifoaming reagent improved the cultivation system by completely preventing foam formation. This reduced the release of lactate dehydrogenase activity to the level found in bubble-free aerated stirred tank membrane bioreactors and led to a reduction in generation doubling times by about 5 h (17%). Using the optimized medium formulation, cells were cultivated at a 1000-L scale, resulting in a culture performance comparable to the 20-L airlift bioreactor. For comparison, cultivations with protein-containing SMIF7 medium were carried out at 20- and 1000-L scales. The application of protein supplements did not lead to a significant improvement in the cultivation conditions. The results were also compared with experiments performed in a bubble-free aerated stirred tank membrane bioreactor to evaluate the influence of bubbles on the investigated culture parameters. The data implied a higher metabolic activity of the cells in airlift bioreactors with a 150% higher glucose consumption rate. The results of this study clearly demonstrate the applicability of a protein-free chemically defined medium for the production of recombinant proteins with BHK cells in airlift bioreactors.

Trauma to the pontomesencephalic brainstem-a major clue to the prognosis of severe traumatic brain injury

The objective of this study was to assess the significance of an injury to the pontomesencephalic brainstem in severe traumatic brain injury [Glasgow coma score (GCS) below 8]. Forty victims of severe traumatic brain injury with and with out compounding pathologies almost equally distributed among both groups were studied. The outcome (mean follow-up, 11.3 months) was assessed by means of the Glasgow outcome score (GOS) and of the Disability rating scale (DRS). Injury of the brainstem was detected by electrophysiological investigation (evoked potentials, brainstem reflexes) and magnetic resonance imaging (MRI) carried out early after trauma. Statistical analysis (Wilcoxon signed rank test for matched pairs) revealed a significantly worse initial GCS (median 5 versus 6), GOS (median 3 versus 4), and DRS score (median 6 versus 2) for the group with brainstem lesions than for the group without such lesions. Moreover, there was a significant accumulation of lesions of the corpus callosum, the basal ganglia, and the (para-)hippocampal area detected by MRI in the brainstem lesion group. In addition, the finding of an abnormal cortical component of the median nerve evoked somatosensory potential was significantly more frequent in the patients with brainstem injury. Traumatic brainstem lesions diagnosed by MRI a nd/or electrophysiological investigation are associated with injury to other 'deeply' situated parts ofthe brain. The finding of a brainstem lesion influences to the outcome of patients after severe traumatic brain injury.

Surgery of intrinsic cerebral neoplasms in eloquent areas under local anesthesia

28 patients with a mean age of 43.6 years were operated on for a cerebral neoplasm situated in close proximity to an eloquent area (24 speech area, 4 motor cortex) from 1996 to 1999. Preoperatively, all patients had undergone a detailed neuropsychological examination. In 10 patients aphasic disturbances could be detected. All patients underwent preoperative PET studies (methionine and (15)O-labeled water with activation during speech or finger tapping). These were performed and co-registered with MRI data to demonstrate the topographical relationship between motor or language function and the tumor borders. Anesthesia was induced with i.v. administration of propofol (150-250 mg/h). Craniotomy was performed under local infiltration anesthesia. After opening of the dura, sedation was stopped and operation was continued with the patient being alert and co-operative. With close clinical observation during electrical cortex stimulation, a speech arrest could be triggered or avoided. The motor cortex was identified by recording the phase reversal of the contralateral SEP of the median nerve and by direct cortical stimulation. As soon as aphasic or motor disturbances appeared, the tumor removal was continued with the goal of avoiding these specific regions. In 27 patients, preexisting neuropsychological and neurological deficits did not worsen. Only one patient was left postoperatively with a major permanent aphasic deficit that was present preoperatively to a minor degree. The use of local anesthesia in craniotomy for surgery of intrinsic cerebral neoplasms in eloquent areas allows for a continuous and repetitive monitoring of speech and motor function during the removal of even those tumors that were previously considered inoperable.

[Antiviral therapy of hepatitis C]

Hepatitis C is one of the world's leading infectious diseases. The interferon-ribavirin combination therapy is the new standard for the treatment of hepatitis C in naive and relapse patients. Virological sustained response rates can be more than doubled by the IFN-ribavirin combination therapy compared to IFN-monotherapy and treatment duration can be reduced to six months in many cases. The IFN-ribavirin combination therapy has a high relative benefit in patients with unfavorable predictive parameters like high viral load, HCV genotype-1 infection and compensated liver cirrhosis. Anemia is the most important side effect of the guanosin analogue ribavirin. There are no official therapeutic recommendations for non-responder patients at present. These patients should be treated within controlled clinical trials. Monotherapy with PEG(pegylated)-interferons and combination therapies with PEG-interferons and ribavirin are the most promising future therapeutic options.

Quantitative surface analysis by total electron yield

When the surface of a solid sample is irradiated under vacuum by x-rays an electron emission, owing to photoabsorption, can be measured. As the electrons are detected under neglection of their kinetic energies the total electron yield (TEY) is determined. With a tuneable x-ray monochromator the TEY is measured below and above of one of the absorption edges of a given element. A jumplike increase of the TEY signal, due to the additional photoabsorptions in the corresponding atomic level, can be observed - qualitative analysis. The height of this jump can be correlateted to the concentration - quantitative analysis. It can be shown by a fundamental parameter approach for primary and secondary excitations how to use TEY for a quantitative analysis. The information depth lambda of this new method is approximately 2-400 nm depending on the chemical elements and on the original kinetic energies of Auger and photoelectrons. Thus, TEY is located between photoelectron spectrometry and x-ray fluorescence analysis.

Pressor, renal and endocrine effects of L-arginine in essential hypertensives

The pressor, renal and endocrine effect of the physiological precursor of endothelial derived nitric oxide, L-arginine was compared, with a substrate inactive on nitric oxide, hypertonic D-glucose, in hypertensive patients. Ten mild-moderate essential hypertensives were assigned to either L-arginine (n = 5) or D-glucose (n = 5). Substances were infused over 25 min at equiosmolal rates preceded and followed by saline infusion for 25 min. Blood pressure and heart rate were monitored at 3-min intervals, while hormonal and humoral variables, inulin and paraaminohippurate clearance and electrolyte excretion were measured at the end of each period under conditions of maximal diuresis. L-arginine and D-glucose increased serum osmolality comparably and caused similar haemodilution to that with control saline. During L-arginine infusion, systolic and diastolic blood pressure decreased by 16.6% and 11%, respectively, and recovered in the postinfusion period. Heart rate, plasma renin activity, and plasma noradrenaline did not change significantly. The percent blood pressure decrement induced by L-arginine was significantly greater than that by D-glucose. Glomerular filtration rate was stable and renal plasma flow was increased by both substances. However, natriuresis, kaliuresis and chloruresis were markedly stimulated only by L-arginine, which also promoted the development of systemic acidosis, possibly as a consequence of hydrochloridric acid generated during its metabolism. Circulating insulin, atrial natriuretic peptide, growth hormone and glucagon levels were increased and plasma aldosterone was unchanged during infusion of L-arginine. Insulin was stimulated and the other hormones inhibited during infusion of D-glucose.(ABSTRACT TRUNCATED AT 250 WORDS)

[Pressor, renal and endocrine effects of systemic infusion of L-arginine in hypertensive patients]

In this study we compared the pressor, renal and endocrine effects of the physiological precursor of endothelial derived nitric oxide, L-arginine, with D-glucose, a substrate inactive on nitric oxide. Ten subjects with mild to moderate primary hypertension underwent infusion with either L-arginine (5 patients) or D-glucose (5 patients). The substances were infused over 25 min at equiosmolar rates, preceded and followed by a 25-min saline infusion. Blood pressure (BP) and heart rate were monitored at 3-min intervals; hormonal and humoral variables, inulin and para-aminohippurate clearance, and electrolyte excretion were measured at the end of each period at maximum diuresis. L-arginine and D-glucose brought about comparable increases in serum osmolality and similar hemodilution as compared with control saline. During L-arginine infusion, systolic and diastolic BP dropped by 16.6% and 11% respectively and recovered during the post-infusion period. Heart rate, plasma renin activity, and plasma norepinephrine did not change significantly. The percent BP decrease induced by L-arginine was significantly greater than that caused by D-glucose. Glomerular filtration rate remained stable, and renal plasma flow increased with both substances. However, only L-arginine stimulated markedly natriuresis, kaliuresis, and chloruresis. It also seemed to induce systemic acidosis, possibly as a consequence of hydrochloric acid generated during its metabolism. Circulating insulin, atrial natriuretic peptide, growth hormone, and glucagon levels increased, and plasma aldosterone remained unchanged during L-arginine infusion. During D-glucose infusion, insulin was stimulated and the other hormones were inhibited.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics of vigabatrin: implications of creatinine clearance

The pharmacokinetics of both enantiomers of vigabatrin after a single oral dose in healthy young subjects (mean creatinine clearance 120 ml/min) were compared with kinetics in two groups of elderly subjects, one group aged 60 to 75 years (mean creatinine clearance 86 ml/min) and one group aged 76 to 97 years (mean creatinine clearance 30 ml/min). At a dose of 1500 mg, the group with the eldest subjects and the lowest creatinine clearance values showed mean increases of 3.3-fold in the time to reach the maximum concentration, 2.7-fold in the maximum concentration, and 9.8-fold in the AUC; a twofold prolongation of the t1/2; and reduced urinary excretion of the biologically and pharmacologically active S(+)-enantiomer. Changes in the intermediate group were qualitatively similar but quantitatively less. Parallel observations were made for the inactive R(-)-enantiomer. Most of these changes can be related to decreased renal clearance of vigabatrin. No interference of either enantiomer in the renal clearance of the other was noted. A nonlinear relationship between renal clearance and creatinine clearance for both enantiomers is suggested. Knowledge of the patient's renal function and an appropriate dose adjustment will minimize side effects during vigabatrin therapy, especially in elderly patients.

Pseudomembranous colitis associated with ampicillin and erythromycin therapy: report of a case

Pseudomembranous colitis has been observed increasingly often after therapy with several antibiotics. This report describes the case of a patient in whom pseudomembranous colitis developed in association with ampicillin, an extremely rare complication of this drug, and erythromycin, a drug that has not been previously reported to cause the disease. Clinical and pathologic features, pathogenesis, and management are discussed. Early diagnosis and treatment are extremely important to reduce the significant morbidity and mortality associated with this disorder.