Blood CD9+ B cell, a biomarker of bronchiolitis obliterans syndrome after lung transplantation

Bronchiolitis obliterans syndrome is the main limitation for long-term survival after lung transplantation. Some specific B cell populations are associated with long-term graft acceptance. We aimed to monitor the B cell profile during early development of bronchiolitis obliterans syndrome after lung transplantation. The B cell longitudinal profile was analyzed in peripheral blood mononuclear cells from patients with bronchiolitis obliterans syndrome and patients who remained stable over 3 years of follow-up. CD24^hi CD38^hi transitional B cells were increased in stable patients only, and reached a peak 24 months after transplantation, whereas they remained unchanged in patients who developed a bronchiolitis obliterans syndrome. These CD24^hi CD38^hi transitional B cells specifically secrete IL-10 and express CD9. Thus, patients with a total CD9⁺ B cell frequency below 6.6% displayed significantly higher incidence of bronchiolitis obliterans syndrome (AUC = 0.836, PPV = 0.75, NPV = 1). These data are the first to associate IL-10-secreting CD24^hi CD38^hi transitional B cells expressing CD9 with better allograft outcome in lung transplant recipients. CD9-expressing B cells appear as a contributor to a favorable environment essential for the maintenance of long-term stable graft function and as a new predictive biomarker of bronchiolitis obliterans syndrome-free survival.

Primary cell-based phenotypic assays to pharmacologically and genetically study fibrotic diseases in vitro

Ongoing tissue repair and formation and deposition of collagen-rich extracellular matrix in tissues and organs finally lead to fibrotic lesions and destruction of normal tissue/organ architecture and function. In the lung, scarring is observed in asthma, chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis to various degrees. At the cellular level immune cells, fibroblasts and epithelial cells are all involved in fibrotic processes. Mechanistically, fibroblast to myofibroblast transformation and epithelial to mesenchymal transition are major drivers of fibrosis. Amongst others, both processes are controlled by transforming growth factor beta-1 (TGFβ-1), a growth factor upregulated in idiopathic pulmonary fibrosis lungs. Phenotypic assays with primary human cells and complex disease-relevant readouts become increasingly important in modern drug discovery processes. We describe high-content screening based phenotypic assays with primary normal human lung fibroblasts and primary human airway epithelial cells. For both cell types, TGFβ-1 stimulation is used to induce fibrotic phenotypes in vitro, with alpha smooth muscle actin and collagen-I as readouts for FMT and E-cadherin as a readout for EMT. For each assay, a detailed image analysis protocols is described. Treatment of both cell types with TGFβ-1 and a transforming growth factor beta receptor inhibitor verifies the suitability of the assays for pharmacological interventions. In addition, the assays are compatible for siRNA and Cas9-ribonucleoprotein transfections, and thus are useful for genetic target identification/validation by modulating gene expression.

Methylation patterns in serum DNA for early identification of disseminated breast cancer

BACKGROUND

Monitoring treatment and early detection of fatal breast cancer (BC) remains a major unmet need. Aberrant circulating DNA methylation (DNAme) patterns are likely to provide a highly specific cancer signal. We hypothesized that cell-free DNAme markers could indicate disseminated breast cancer, even in the presence of substantial quantities of background DNA.

METHODS

We used reduced representation bisulfite sequencing (RRBS) of 31 tissues and established serum assays based on ultra-high coverage bisulfite sequencing in two independent prospective serum sets (n = 110). The clinical use of one specific region, EFC#93, was validated in 419 patients (in both pre- and post-adjuvant chemotherapy samples) from SUCCESS (Simultaneous Study of Gemcitabine-Docetaxel Combination adjuvant treatment, as well as Extended Bisphosphonate and Surveillance-Trial) and 925 women (pre-diagnosis) from the UKCTOCS (UK Collaborative Trial of Ovarian Cancer Screening) population cohort, with overall survival and occurrence of incident breast cancer (which will or will not lead to death), respectively, as primary endpoints.

RESULTS

A total of 18 BC specific DNAme patterns were discovered in tissue, of which the top six were further tested in serum. The best candidate, EFC#93, was validated for clinical use. EFC#93 was an independent poor prognostic marker in pre-chemotherapy samples (hazard ratio [HR] for death = 7.689) and superior to circulating tumor cells (CTCs) (HR for death = 5.681). More than 70% of patients with both CTCs and EFC#93 serum DNAme positivity in their pre-chemotherapy samples relapsed within five years. EFC#93-positive disseminated disease in post-chemotherapy samples seems to respond to anti-hormonal treatment. The presence of EFC#93 serum DNAme identified 42.9% and 25% of women who were diagnosed with a fatal BC within 3-6 and 6-12 months of sample donation, respectively, with a specificity of 88%. The sensitivity with respect to detecting fatal BC was ~ 4-fold higher compared to non-fatal BC.

CONCLUSIONS

Detection of EFC#93 serum DNAme patterns offers a new tool for early diagnosis and management of disseminated breast cancers. Clinical trials are required to assess whether EFC#93-positive women in the absence of radiological detectable breast cancers will benefit from anti-hormonal treatment before the breast lesions become clinically apparent.

The potential of circulating tumor DNA methylation analysis for the early detection and management of ovarian cancer

Background

Despite a myriad of attempts in the last three decades to diagnose ovarian cancer (OC) earlier, this clinical aim still remains a significant challenge. Aberrant methylation patterns of linked CpGs analyzed in DNA fragments shed by cancers into the bloodstream (i.e. cell-free DNA) can provide highly specific signals indicating cancer presence.

Methods

We analyzed 699 cancerous and non-cancerous tissues using a methylation array or reduced representation bisulfite sequencing to discover the most specific OC methylation patterns. A three-DNA-methylation-serum-marker panel was developed using targeted ultra-high coverage bisulfite sequencing in 151 women and validated in 250 women with various conditions, particularly in those associated with high CA125 levels (endometriosis and other benign pelvic masses), serial samples from 25 patients undergoing neoadjuvant chemotherapy, and a nested case control study of 172 UKCTOCS control arm participants which included serum samples up to two years before OC diagnosis.

Results

The cell-free DNA amount and average fragment size in the serum samples was up to ten times higher than average published values (based on samples that were immediately processed) due to leakage of DNA from white blood cells owing to delayed time to serum separation. Despite this, the marker panel discriminated high grade serous OC patients from healthy women or patients with a benign pelvic mass with specificity/sensitivity of 90.7% (95% confidence interval [CI] = 84.3–94.8%) and 41.4% (95% CI = 24.1–60.9%), respectively. Levels of all three markers plummeted after exposure to chemotherapy and correctly identified 78% and 86% responders and non-responders (Fisher’s exact test, p = 0.04), respectively, which was superior to a CA125 cut-off of 35 IU/mL (20% and 75%). 57.9% (95% CI 34.0–78.9%) of women who developed OC within two years of sample collection were identified with a specificity of 88.1% (95% CI = 77.3–94.3%). Sensitivity and specificity improved further when specifically analyzing CA125 negative samples only (63.6% and 87.5%, respectively).

Conclusions

Our data suggest that DNA methylation patterns in cell-free DNA have the potential to detect a proportion of OCs up to two years in advance of diagnosis and may potentially guide personalized treatment. The prospective use of novel collection vials, which stabilize blood cells and reduce background DNA contamination in serum/plasma samples, will facilitate clinical implementation of liquid biopsy analyses.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-017-0500-7) contains supplementary material, which is available to authorized users.

Granger-causality maps of diffusion processes

Granger causality is a statistical concept devised to reconstruct and quantify predictive information flow between stochastic processes. Although the general concept can be formulated model-free it is often considered in the framework of linear stochastic processes. Here we show how local linear model descriptions can be employed to extend Granger causality into the realm of nonlinear systems. This novel treatment results in maps that resolve Granger causality in regions of state space. Through examples we provide a proof of concept and illustrate the utility of these maps. Moreover, by integration we convert the local Granger causality into a global measure that yields a consistent picture for a global Ornstein-Uhlenbeck process. Finally, we recover invariance transformations known from the theory of autoregressive processes.

DNA methylation markers for early detection of women's cancer: promise and challenges

Breast, ovarian and endometrial cancers cause significant morbidity and mortality. Despite the presence of existing screening, diagnostic and treatment modalities, they continue to pose considerable unsolved challenges. Overdiagnosis is a growing problem in breast cancer screening and neither screening nor early diagnosis of ovarian or endometrial cancer is currently possible. Moreover, treatment of the diversity of these cancers presenting in the clinic is not sufficiently personalized at present. Recent technological advances, including reduced representation bisulfite sequencing, methylation arrays, digital PCR, next-generation sequencing and advanced statistical data analysis, enable the analysis of methylation patterns in cell-free tumor DNA in serum/plasma. Ongoing work is bringing these methods together for the analysis of samples from large clinical trials, which have been collected well in advance of cancer diagnosis. These efforts pave the way for the development of a noninvasive method that would enable us to overcome existing challenges to personalized medicine.

Comparing High-throughput Platforms for Sequencing the V4 Region of SSU-rDNA in Environmental Microbial Eukaryotic Diversity Surveys

High-throughput sequencing platforms are continuing to increase resulting read lengths, which is allowing for a deeper and more accurate depiction of environmental microbial diversity. With the nascent Reagent Kit v3, Illumina MiSeq now has the ability to sequence the eukaryotic hyper-variable V4 region of the SSU-rDNA locus with paired-end reads. Using DNA collected from soils with analyses of strictly- and nearly identical amplicons, here we ask how the new Illumina MiSeq data compares with what we can obtain with Roche/454 GS FLX with regard to quantity and quality, presence and absence, and abundance perspectives. We show that there is an easy qualitative transition from the Roche/454 to the Illumina MiSeq platforms. The ease of this transition is more nuanced quantitatively for low-abundant amplicons, although estimates of abundances are known to also vary within platforms.

Carbonic anhydrase IV is expressed on IL-5-activated murine eosinophils

Eosinophilia and its cellular activation are hallmark features of asthma, as well as other allergic/Th2 disorders, yet there are few, if any, reliable surface markers of eosinophil activation. We have used a FACS-based genome-wide screening system to identify transcriptional alterations in murine lung eosinophils recruited and activated by pulmonary allergen exposure. Using a relatively stringent screen with false-positive correction, we identified 82 candidate genes that could serve as eosinophil activation markers and/or pathogenic effector markers in asthma. Carbonic anhydrase IV (Car4) was a top dysregulated gene with 36-fold induction in allergen-elicited pulmonary eosinophils, which was validated by quantitative PCR, immunohistochemistry, and flow cytometry. Eosinophil CAR4 expression was kinetically regulated by IL-5, but not IL-13. IL-5 was both necessary and sufficient for induction of eosinophil CAR4. Although CAR4-deficient mice did not have a defect in eosinophil recruitment to the lung, nor a change in eosinophil pH-buffering capacity, allergen-challenged chimeric mice that contained Car4(-/-) hematopoietic cells aberrantly expressed a series of genes enriched in biological processes involved in epithelial differentiation, keratinization, and anion exchange. In conclusion, we have determined that eosinophils express CAR4 following IL-5 or allergen exposure, and that CAR4 is involved in regulating the lung transcriptome associated with allergic airway inflammation; therefore, CAR4 has potential value for diagnosing and monitoring eosinophilic responses.

Age, microbiota, and T cells shape diverse individual IgA repertoires in the intestine

Intestinal immunoglobulin A (IgA) ensures host defense and symbiosis with our commensal microbiota. Yet previous studies hint at a surprisingly low diversity of intestinal IgA, and it is unknown to what extent the diverse Ig arsenal generated by somatic recombination and diversification is actually used. In this study, we analyze more than one million mouse IgA sequences to describe the shaping of the intestinal IgA repertoire, its determinants, and stability over time. We show that expanded and infrequent clones combine to form highly diverse polyclonal IgA repertoires with very little overlap between individual mice. Selective homing allows expanded clones to evenly seed the small but not large intestine. Repertoire diversity increases during aging in a dual process. On the one hand, microbiota-, T cell-, and transcription factor RORγt-dependent but Peyer's patch-independent somatic mutations drive the diversification of expanded clones, and on the other hand, new clones are introduced into the repertoire of aged mice. An individual's IgA repertoire is stable and recalled after plasma cell depletion, which is indicative of functional memory. These data provide a conceptual framework to understand the dynamic changes in the IgA repertoires to match environmental and intrinsic stimuli.

The pan-B cell marker CD22 is expressed on gastrointestinal eosinophils and negatively regulates tissue eosinophilia

CD22 is currently recognized as a B cell-specific Siglec and has been exploited therapeutically with humanized anti-CD22 mAb having been used against B cell leukemia. In this study, tissue-specific eosinophil mRNA microarray analysis identified that CD22 transcript levels of murine gastrointestinal (GI) eosinophils are 10-fold higher than those of lung eosinophils. To confirm the mRNA data at the protein level, we developed a FACS-based protocol designed to phenotype live GI eosinophils isolated from the murine lamina propria. Indeed, we found that jejunum eosinophils expressed remarkably high levels of surface CD22, similar to levels found in B cells across multiple mouse strains. In contrast, CD22 was undetectable on eosinophils from the colon, blood, thymus, spleen, uterus, peritoneal cavity, and allergen-challenged lung. Eosinophils isolated from newborn mice did not express CD22 but subsequently upregulated CD22 expression to adult levels within the first 10 d after birth. The GI lamina propria from CD22 gene-targeted mice harbored more eosinophils than wild type control mice, whereas the GI eosinophil turnover rate was unaltered in the absence of CD22. Our findings identify a novel expression pattern and tissue eosinophilia-regulating function for the "B cell-specific" inhibitory molecule CD22 on GI eosinophils.

High TCR diversity ensures optimal function and homeostasis of Foxp3+ regulatory T cells

Dominant tolerance to self-antigen requires the presence of sufficient numbers of CD4(+) Foxp3(+) Treg cells with matching antigen specificity. However, the size and role of TCR repertoire diversity for antigen-specific immuno-regulation through Treg cells is not clear. Here, we developed and applied a novel high-throughput (HT) TCR sequencing approach to analyze the TCR repertoire of Treg cells and revealed the importance of high diversity for Treg-cell homeostasis and function. We found that highly polyclonal Treg cells from WT mice vigorously expanded after adoptive transfer into non-lymphopenic TCR-transgenic recipients with low Treg-cell diversity. In that system, we identified specific Treg-cell TCR preferences in distinct anatomic locations such as the mesenteric LN indicating that Treg cells continuously compete for MHC class-II-presented self-, food-, or flora-antigen. Functionally, we showed that high TCR diversity was required for optimal suppressive function of Treg cells in experimental acute graft versus host disease (GvHD). In conclusion, we suggest that efficient immuno-regulation by Treg cells requires high TCR diversity. Thereby, continuous competition of peripheral Treg cells for limited self-antigen shapes an organ-optimized, yet highly diverse, local TCR repertoire.

[Paediatric pseudophakia - refractive changes after primary and secondary intraocular lens implantation]

BACKGROUND

A so-called myopic shift after cataract extraction and IOL implantation is known to occur in children. How much is difficult to predict. In this study we report the refractive development in pseudophakic children after primary and secondary IOL implantation.

METHODS

The refractive change in all patients receiving an IOL-implantation between 2000 and 2008 with a follow-up of a minimum of 6 months was reviewed (6 - 107 months). Rigid or foldable lenses were implanted by the same technique. Refraction postoperatively and at last follow-up was measured. 62 eyes of 41 patients were reviewed. Patients were divided into three groups based on age at time of surgery: 3 - 4 years, 5 - 6 years and 7 - 12 years.

RESULTS

The mean myopic shift was 2.5 D in both study groups, patients with primary and secondary IOL implantation. In the group with 3 - 4-year-old children mean myopic shift was 1.5 D in primary and 1.0 D in secondary implantations, in the group with 5 - 6-year-old children 2.75 D in primary and 3.25 D in secondary implantations and in the group with 7 - 12-year-old children 2.0 D in both primary and secondary implanted IOLs.

CONCLUSIONS

We have shown that there are no differences in refractive changes between primary and secondary IOL implantations in our study group. In contrast to other findings we found the lowest myopic shift in the group of 3 - 4-year-old patients. Our results show that a prediction of expected myopic shift in children after IOL implantations remains difficult.

Common gamma-chain-dependent signals confer selective survival of eosinophils in the murine small intestine

Eosinophils are potent effector cells that are recruited to sites of inflammation. However, in some tissues, in particular in the gastrointestinal tract, eosinophils constitute an abundant leukocyte population also under homeostatic conditions. The lack of suitable isolation protocols restricted the analysis of these cells to histological assessment of cell numbers while important aspects of their phenotype, turnover, and functions remain unresolved. In this study, we report a protocol that allows the quantitative isolation of intestinal eosinophils. We characterized small intestinal eosinophils by flow cytometry as SSC(high)CD11b(+)CD11c(+)CCR3(+)Siglec-F(+) cells. Intestinal eosinophils resembled eosinophils isolated from thymus and uterus but differed from eosinophils isolated from lung or blood. Eosinophils in intestine, thymus, and uterus showed in vivo a markedly higher life time compared with eosinophils present in lung and blood measured by incorporation of BrdU. This indicates that under steady-state conditions homeostasis of eosinophils is controlled by regulation of cell survival. Intestinal eosinophils are severely reduced in the intestines of Rag-2/common gamma-chain double-deficient mice but not Rag-2-deficient mice, correlating with differential expression of GM-CSF and CCL11 in both mouse strains. Moreover, under steady-state conditions, intestinal eosinophils constitutively express high levels of the common gamma-chain transcripts compared with lung eosinophils as well as eosinophils present under inflammatory conditions. These observations reveal a hitherto unrecognized diversity in phenotypic and functional properties of eosinophils and suggest that tissue-specific common gamma-chain-dependent signals might profoundly affect eosinophil function and homeostasis.

Superspace description of the modulated structure of the metal-salt-hybrid Bi7 − δNi2Br5 − 2δ (δ = 1/9)

The compound Bi7 − δNi2Br5 − 2δ = (Bi3Ni)2[Bi1 − δBr4]Br1 −2δ (δ = 1/9) is a sub-bromide of the intermetallic phase Bi3Ni. Its crystal structure contains metallic rods, ^1_{\infty}[Bi3Ni], which are embedded in a salt-like matrix of bromido-bismuthate(III) and bromide anions. The non-stoichiometry originates from the variation of the number n of trans edge-sharing octahedra in the [Bi n Br4n + 2](n + 2)− oligomers (3 ≤ n ≤ 5), as well as from vacancies on the sites of the isolated Br atoms. The simplified structure is described in the orthorhombic space group Cmcm with a = 4.0660 (4), b = 23.305 (3), c = 17.130 (2) Å. It shows a statistical distribution of vacancies and orientational disorder of the concatenated octahedra. By choosing the modulation vector q = a*/9 + b*/2, the additional weak reflections of the diffraction pattern can be indexed. In the [3 + 1]-dimensional superspace group Pmnm(α½0)000, an ordered structure model is achieved. The modulated crystal structure bears a strong resemblance to the somewhat higher oxidized sub-bromide Bi7 − δNi2Br5 (δ = 1/9).

Mesenteric lymph node stroma cells in the generation of intestinal immune responses

Lymph nodes at different anatomical locations share similar architecture and operate on the basis of identical principles. Still, the quality of immune responses is modified substantially by the local peculiarities at the site of its induction. Here, we discuss how lymph node stroma cells contribute to functional differences between various lymph nodes, thus helping to explain why and how an immune response induced in skin draining peripheral lymph nodes differs from that elicited in the gut draining mesenteric lymph nodes. Stroma cells constitute a major part of the lymph node scaffold and control the flow of immune cells as well as soluble substances within the organ. Moreover, stroma cells express cytokines, chemokines as well as adhesion factors and thereby actively influence immune status. Lymph node transplantations and adoptive transfers of dendritic cells demonstrated that regional lymph node stroma cells differ in their ability to support mucosal tolerance, the induction of tissue tropism, and humoral immunity. This suggests that stroma cells shape tissue-specific immune responses and equip lymph nodes with unique functional properties that might originate during lymph node organogenesis.

Stromal mesenteric lymph node cells are essential for the generation of gut-homing T cells in vivo

T cells primed in the gut-draining mesenteric lymph nodes (mLN) are imprinted to express alpha4beta7-integrin and chemokine receptor CCR9, thereby enabling lymphocytes to migrate to the small intestine. In vitro activation by intestinal dendritic cells (DC) or addition of retinoic acid (RA) is sufficient to instruct expression of these gut-homing molecules. We report that in vivo stroma cells, but not DC, allow the mLN to induce the generation of gut tropism. Peripheral LN (pLN) transplanted into the gut mesenteries fail to support the generation of gut-homing T cells, even though gut-derived DC enter the transplants and prime T cells. DC that fail to induce alpha4beta7-integrin and CCR9 in vitro readily induce these factors in vivo upon injection into mLN afferent lymphatics. Moreover, uniquely mesenteric but not pLN stroma cells express high levels of RA-producing enzymes and support induction of CCR9 on activated T cells in vitro. These results demonstrate a hitherto unrecognized contribution of stromal cell delivered signals, including RA, on the imprinting of tissue tropism in vivo.

[Clinical and radiological results of surgical removal of periarticular ossifications after hip prosthesis implantation]

The occurrence of heterotopic ossification (HO) is a well-recognized problem after total hip replacement. In a retrospective study, we investigated 32 patients who had undergone surgical excision of symptomatic HO followed by radiation with 7 Gy and nonsteroidal anti-inflammatory drug therapy between 1994 and 1999. The mean follow-up was 20 months (range: 12-60). Clinical and radiographic follow-up examinations included Harris hip score and classification according to Brooker. The preoperative Brooker class was III in 16 cases and IV in 16 patients. Comparison of the Brooker classification at follow-up revealed a statistically significant improvement (p < 0.0001; class 0:3, class I: 14, class II: 8, class III: 7 patients). In one case with symptomatic Brooker class III ossification, surgical reexcision of HO was necessary. A statistically significant increase (p < 0.05) in mean range of motion (ROM) was observed in flexion [preoperative: 57 degrees (+/- 26), follow-up: 83 degrees (+/- 21)], in abduction [preoperative: 17 degrees (+/- 12), follow-up: 24 degrees (+/- 9)], and in rotation (preoperative: 16 degrees (+/- 17), follow-up: 31 degrees (+/- 18)]. Comparison of preoperative Harris hip score (60 +/- 11) and Harris hip score at the time of follow-up examination (73 +/- 17) revealed a statistically significant increase (p < 0.0001) after treatment. At the time of follow-up examination, 18 patients (56%) assessed their pain symptoms as low but 6 patients (19%) reported strong pain symptoms. Nevertheless, the score at the time of examination (35 +/- 10) was statistically improved (p < 0.02) when compared to the preoperative score (30 +/- 8). Surgical excision of Brooker class III or IV heterotopic ossification with limited ROM followed by irradiation and anti-inflammatory prophylaxis results in significant improvement in flexion, abduction, and rotation arc and significant reduction of HO in radiographic examination at follow-up, but pain relief was only satisfactory.

[The aging of mentally handicapped within the family and society]

The increase of the hope of life of the population poses specific problems, and often harrowing for the families with a mentally handicapped relative. Will be able the society to take up the challenge issued by the medicine and a better standard of living, in accompanying all its members with dignity.

[Results of operative therapy of periprosthetic femur shaft fractures in total hip endoprostheses]

Periprosthetic femoral shaft fracture represents an uncommon but potentially devastating complication associated with total hip arthroplasty. The treatment should result in complete union of the fracture and at the same time guarantee stability of the implant. 15 patients treated between 1992 to 1998 were analysed. Clinical and radiographic follow-up averaged 30 months (6-79 months) in 13 cases. Two patients died regardless of the fracture. The method of treatment depended on the intraoperative stability of the prosthesis and in addition on the fracture type (Bethea). In 5 cases of intraoperative stability of the prosthesis plate fixation was performed. Plate fixation was complicated by fixation failure combined with a recurrent fracture in two cases leading to shift to a long stem prosthesis. Ten cases of fractures associated with loose stems were treated with a new prosthesis using a long stem system. In these cases an uncomplicated healing of the fracture was achieved with adequate stability in radiographic examinations. The average Harris score was 70 (26-93). For fractures near the femoral stem or in case of implant loosening we recommend the shift to a long stem prosthesis. Also in fractures distally from the femoral stem tip we prefer now long stem implants rather than plate fixation to avoid large exposure of the femoral shaft and resultant complications.

Influence of stimulus cross talk on results of the twitch-interpolation technique at the biceps brachii muscle

Biceps brachii muscles of five healthy volunteers were tested with a high-resolution twitch-interpolation technique. Parameters of the electrical surface stimulation were varied. It was found that a supramaximal stimulus strength activates both biceps and triceps brachii motor units simultaneously severely affecting twitch-interpolation results. Crosstalk contamination of twitches, however, can be avoided, if submaximal stimuli are used yielding twitch-interpolation results for the biceps-brachii that are similar to those of the quadriceps muscle.

Metabolites of microorganisms. 242 pyridindolol glucosides from Streptomyces parvulus

From a new strain of Streptomyces, Streptomyces parvulus, strain Tü 2480 three glucosides of the alkaloid pyridindolol were isolated. The structure elucidation is based on spectroscopic investigations and degradation to pyridindolol and alpha,D-methyl glucoside.