Network analysis: a new approach to study endocrine disorders

Systems biology is the study of the interactions that occur between the components of individual cells - including genes, proteins, transcription factors, small molecules, and metabolites, and their relationships to complex physiological and pathological processes. The application of systems biology to medicine promises rapid advances in both our understanding of disease and the development of novel treatment options. Network biology has emerged as the primary tool for studying systems biology as it utilises the mathematical analysis of the relationships between connected objects in a biological system and allows the integration of varied 'omic' datasets (including genomics, metabolomics, proteomics, etc.). Analysis of network biology generates interactome models to infer and assess function; to understand mechanisms, and to prioritise candidates for further investigation. This review provides an overview of network methods used to support this research and an insight into current applications of network analysis applied to endocrinology. A wide spectrum of endocrine disorders are included ranging from congenital hyperinsulinism in infancy, through childhood developmental and growth disorders, to the development of metabolic diseases in early and late adulthood, such as obesity and obesity-related pathologies. In addition to providing a deeper understanding of diseases processes, network biology is also central to the development of personalised treatment strategies which will integrate pharmacogenomics with systems biology of the individual.

Arsenic-containing hydrocarbons are toxic in the in vivo model Drosophila melanogaster

Arsenic-containing hydrocarbons cause developmental toxicity in Drosophila melanogaster.

Evidence for long-range spin order instead of a Peierls transition in si(553)-Au chains

Stabilization of the Si(553) surface by Au adsorption results in two different atomically defined chain types, one of Au atoms and one of Si. At low temperature these chains develop two- and threefold periodicity, respectively, previously attributed to Peierls instabilities. Here we report evidence from scanning tunneling microscopy that rules out this interpretation. The ×3 superstructure of the Si chains vanishes for low tunneling bias, i.e., close the Fermi level. In addition, the Au chains remain metallic despite their period doubling. Both observations are inconsistent with a Peierls mechanism. On the contrary, our results are in excellent, detailed agreement with the Si(553)-Au ground state predicted by density-functional theory, where the ×2 periodicity of the Au chain is an inherent structural feature and every third Si atom is spin polarized.

Radiological anatomy - evaluation of integrative education in radiology

PURPOSE

Evaluation and analysis of the integrative course "Radiological Anatomy" established since 2007 at the Medical School Hannover (MHH) in comparison with conventional education.

MATERIALS AND METHODS

Anatomy and radiology are usually taught separately with a considerable time lag. Interdisciplinary teaching of these associated subjects seems logical for several reasons. Therefore, the integrative course "Radiological Anatomy" was established in the second year of medical education, combining these two closely related subjects. This interdisciplinary course was retrospectively evaluated by consideration of a student questionnaire and staff observations. The advantages and disadvantages of integrative teaching in medical education are discussed.

RESULTS

The course ratings were excellent (median 1; mean 1.3 on a scale of 1 to 6). This is significantly (p < 0.001) better than the average of all evaluated courses in the respective term (grade 2.8). The course improved the anatomical comprehension (90 %) and the students stated that the topics were relevant for their future medical education (90 %). Furthermore, interest in the subject's anatomy and radiology increased during the course (88 %). According to the students' suggestions the course was enhanced by a visitation in the Department of Radiology and the additional topic central nervous system.

CONCLUSION

Integrative teaching of anatomy and radiology was well received by the students. Both, anatomical and radiological comprehension and the motivation to learn were improved. However, it should be considered, that the amount of work and time required by the teaching staff is considerably increased compared to traditional teaching.

[Congenital disorders of the lungs and airways--survey of cases at the Paediatric Hospital Erlangen in the period 2000 to 2011]

BACKGROUND

Congenital malformations of the lungs are rare, but might limit the quality of life of the patient. With the increased possibilities of diagnostic and therapeutic procedures during the last decades, these diseases can be recognised and successfully treated earlier than before. The aim of this article is to give an overview about the congenital malformations of the lungs in children who have been treated at the Kinderklinik Erlangen during the years 2000 and 2011. Clinical symptoms of the disease and associated malformations, diagnostic and therapeutic procedures were discussed.

METHODS

The analysis was done retrospectively (January 1st 2000-April 15th 2011) on the basis of the patients records. Patients who had been treated only at the outpatient clinic were not considered. All patients' data were listed according to the ICD code.

RESULTS

121 children were treated because of a congenital malformation of the lungs in the years between 2000 and 2011 in Erlangen. 68.6 % (n = 83) were males and 31.45 % (n = 38) were females. Nearly all of the malformations of the lungs were associated with other abnormalities. Most of the children also suffered from at least one cardiac defect. 28 of the 121 children had more than one malformation of the lungs. The diagnostic and therapeutic interventions correlated with the published recommendations.

CONCLUSIONS

The analysis of the patients' data used in this study indicate the importance of the early diagnosis and treatment. The cooperation of different medical disciplines is mandatory for a good outcome of those children.

Au-induced quantum chains on Ge(001)-symmetries, long-range order and the conduction path

Atomic nanowires on the Au/Ge(001) surface are investigated for their structural and electronic properties using scanning tunneling microscopy (STM) and angle-resolved photoemission spectroscopy (ARPES). STM reveals two distinct symmetries: a c(8 × 2) describing the basic repeating distances, while the fine structure on top of the wires causes an additional superstructure of p(4 × 1). Both symmetries are long-range ordered as judged from low-energy electron diffraction. The Fermi surface is composed of almost perfectly straight sheets. Thus, the electronic states are one-dimensionally confined. Spatial dI/dV maps, where both topography and density of states (DOS) are probed simultaneously, reveal that the DOS at low energies, i.e. the conduction path, is oriented along the chain direction. This is fully consistent with the recently reported Tomonaga-Luttinger liquid phase of Au/Ge(001), with the density of states being suppressed by a power-law towards the Fermi energy.

[Platelet inhibition in clinical practice]

Evidence for a beneficial effect of antiaggregatory treatment is strong for many clinical entities. However, there are controversial situations challenging us in daily practice, such as failure of antiaggregatory therapy (case 1), inconclusive evidence for the benefit of certain antiaggregatory medications (case 2) or increased risk of bleeding in aorto-coronary bypass surgery after irreversible antiaggregation (case 3). The phenomenon of aspirin or clopidogrel resistance means the occurrence of ischemic complications despite adequate antiaggregation. It may be caused by malcompliance, variable bioavailability, drug interactions or genetic polymorphisms. For peripheral arterial occlusive disease, a beneficial effect of aspirin is questioned by recent studies in contrast to the recommendations given in international guidelines. Finally, irreversible inhibition of platelet aggregation by GPIIb/IIIa inhibitors given during percutaneous coronary intervention can be overcome by transfusion of functional platelets to reduce bleeding during subsequent bypass surgery. Further studies will help to improve the management of antiaggregatory therapy in such challenging clinical situations.

[High-resolution manometry of the upper esophageal sphincter]

BACKGROUND

High-resolution manometry (HRM) represents a valuable tool for the evaluation of peristalsis in the oesophagus. Due to the wide spacing of the pressure transducers, however, examination of the upper oesophageal sphincter's relaxation period has not proved satisfactory as yet.

DESIGN

A feasibility study was carried out to clarify whether evaluation of the upper oesophageal sphincter's behaviour during swallows is possible using a catheter with very closely spaced pressure transducers.

SETTING

University hospital.

PROCEDURE

Healthy subjects were analysed using a specially developed catheter as well as a modified software to evaluate whether swallow-associated behaviour could be verified.

RESULTS

Interpreting pressure profiles in terms of resting pressure, residual pressure, relaxation time and maximum peristaltic pressure proved to be feasible. The present analysis supports the existence of distinct dynamic swallow-associated phases, which conform to the phases that had previously been postulated. An additional initial phase, however, should be added.

CONCLUSION

This newly created catheter design in combination with the modified software enable a very detailed evaluation of the sphincter's swallow-associated behaviour and represent a valuable, minimally invasive tool with no exposure to radiation for dysphagia diagnosis as well as treatment planning.

Influence of procalcitonin on decision to start antibiotic treatment in patients with a lower respiratory tract infection: insight from the observational multicentric ProREAL surveillance

Procalcitonin (PCT)-guided antibiotic stewardship is a successful strategy to decrease antibiotic use. We assessed if clinical judgement affected compliance with a PCT-algorithm for antibiotic prescribing in a multicenter surveillance of patients with lower respiratory tract infections (LRTI). Initiation and duration of antibiotic therapy, adherence to a PCT algorithm and outcome were monitored in consecutive adults with LRTI who were enrolled in a prospective observational quality control. We correlated initial clinical judgment of the treating physician with algorithm compliance and assessed the influence of PCT on the final decision to initiate antibiotic therapy. PCT levels correlated with physicians' estimates of the likelihood of bacterial infection (p for trend <0.02). PCT influenced the post-test probability of antibiotic initiation with a greater effect in patients with non-pneumonia LRTI (e.g., for bronchitis: -23 % if PCT ≤ 0.25 μg/L and +31 % if PCT > 0.25 μg/L), in European centers (e.g., in France -22 % if PCT ≤ 0.25 μg/L and +13 % if PCT > 0.25 μg/L) and in centers, which had previous experience with the PCT-algorithm (-16 % if PCT ≤ 0.25 μg/L and +19 % if PCT > 0.25 μg/L). Algorithm non-compliance, i.e. antibiotic prescribing despite low PCT-levels, was independently predicted by the likelihood of a bacterial infection as judged by the treating physician. Compliance was significantly associated with identification of a bacterial etiology (p = 0.01). Compliance with PCT-guided antibiotic stewardship was affected by geographically and culturally-influenced subjective clinical judgment. Initiation of antibiotic therapy was altered by PCT levels. Differential compliance with antibiotic stewardship efforts contributes to geographical differences in antibiotic prescribing habits and potentially influences antibiotic resistance rates.

Lack of association between p53 SNP and FISS in a cat population from Germany

One recent study indicates a significant association between certain single nucleotide polymorphisms (SNPs) in the genomic sequence of feline p53 and feline injection-site sarcoma (FISS). The aim of this study was to investigate the correlation between a specific nucleotide insertion in p53 gene and FISS in a German cat population. Blood samples from 150 German cats were allocated to a control group consisting of 100 healthy cats and a FISS-group consisting of 50 cats with FISS. All blood samples were examined for the presence of the SNP in the p53 gene. Results found the T-insertion at SNP 3 in 20.0% of the cats in the FISS-group and 19.2% of cats in the control-group. No statistically significant difference was observed in allelic distribution between the two groups. Further investigations are necessary to determine the association of SNPs in the feline p53 gene and the occurrence of FISS.

Continuous recording intrarectal pressures during the second phase of labor

Parameters of intrarectal pressure (surface area under pressure curve and peak pressure) recorded with a microsystem device during the second phase of labor showed no significant correlations with baby's weight or mode of delivery.

AIM OF THE STUDY

Was to assess the biomechanical pressures delivered against pelvic floor structures during the second phase of labor in nulliparae women, and to correlate them with obstetrics parameters, i.e. baby's weight and mode of delivery.

MATERIAL

Using a microsystem device placed into the rectum at the beginning of the second phase of labor, two parameters were assessed during the bearing efforts in 59 nulliparae women: the surface area under the pressure curve and the peak pressure.

RESULTS

During 11.5±9 bearing efforts of 99.1±16 s duration, the mean value of surface area under the pressure curve was 32677±26058 cm/s and the mean value of the peak pressure was 60.7±24 cmH(2)O, exceeding 100 cmH(2)O in 10% of women. These two parameters were not correlated with baby's weight (R: 0.19, P: 0.15 and R: 0.05, P: 0.71). In the same way, these two parameters were not correlated with the mode of delivery (spontaneous or forceps/vacuum-assisted). Furthermore, the individual values of these two parameters showed great variation from one woman to another.

CONCLUSION

This study has showed that parameters of biomechanical pressures recorded into the rectum during second phase of labor had no significant correlations with obstetricals parameters, explaining why these latter have poor predicitive value of further pelvic floor problems.

['Laryngeal neuropathy' and 'irritable larynx syndrome': synonyms or distinct entities?]

The term 'laryngeal neuropathy' (LN) has first been used in veterinary medicine to describe an idiopathic and typically exercise induced inspiratory noise in horses.Nowadays, the term is often used in relation with intermittent vocal cord pareses in humans. Some authors use the term 'irritable larynx syndrome' (ILS) in a similar context. This article reviews the state of knowledge regarding LN and ILS and discusses the somewhat confusing terminology.For this systematic review a selective literature research in PubMed has been carried out.35 articles were found, which report on LN in animals and 17 articles reported on humans. 4 of these articles used the term 'irritable larynx syndrome'.Laryngeal neuropathy in horses usually affects the left recurrent laryngeal nerve and results in decreased vocal cord abduction and an inspiratory roaring or whistling noise, particularly during exercise. In dogs LN has been reported to also occur bilaterally. In association with humans LN has not been defined clearly in the literature. The term ILS on the other hand has only been used in relation to humans. The term describes a hypersensitivity of the laryngeal structures towards external stimuli, which causes symptoms such as dyspnea or cough among others. Sufficient knowledge does not exist for either of the 2 diseases, ILS or LN. As of yet, the term LN should not be used in human medicine to describe according symptoms of unknown aetiology. The term 'laryngeal movement disorder' seems a lot more appropriate. The symptom oriented term irritable larynx syndrome also seems suitable to describe laryngeal hypersensitivity appropriately.

Peptidomimetic GnRH antagonist AEZS-115 inhibits the growth of ovarian and endometrial cancer cells

BACKGROUND

AEZS-115 (Aeterna Zentaris GmbH, Frankfurt/M, Germany) is an orally active peptidomimetic antagonist of gonadotropin-releasing hormone (GnRH). In various tumors, an autocrine growth-promoting loop has been described for GnRH. The current study evaluates the antitumor activity and mechanism of action of AEZS-115 in models of ovarian and endometrial cancer.

MATERIALS AND METHODS

Human A2780, Acis2780, OAW-42, Ovcar-3, SKOV-3, Hec1A and Ishikawa cells were analyzed for GnRH receptor expression by reverse transcription polymerase chain reaction (RT-PCR). These cell lines were incubated with AEZS-115 at 1, 10 and 100 μM for 24 h, 48 h, and 72 h and the number of viable cells was determined. Fluorescence activated cell sorting (FACS) cell cycle analyses were performed with increasing concentrations of AEZS-115. Co-treatment experiments of cancer cells with GnRH antagonist cetrorelix and peptidomimetic GnRH antagonist AESZ-115 were carried out.

RESULTS

A2780, Acis2780, OAW-42, Ovcar-3, SKOV-3, Hec1A and Ishikawa cells expressed GnRH receptors as demonstrated by RT-PCR. GnRH antagonist AEZS-115 inhibited growth of all cell lines in a dose- and time-dependent manner. Half maximal inhibitory concentration (IC(50)) values at 48 h of incubation were between 7 and 17.5 μM and for 72 h between 4.5 and 12.5 μM. IC(50) values for ovarian and endometrial cancer cells were rather similar. These results were obtained by tetrazolium salt [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; MTT] assay and confirmed by additional crystal violet staining. Cell cycle FACS analysis revealed that AEZS-115 dose-dependently increased the fraction of apoptotic cells. Co-treatment experiments carried out with AEZS-115 and peptidic GnRH-antagonist cetrorelix suggest that the antitumor effect of AEZS-115 is not mediated by blockade of the GnRH receptor.

CONCLUSION

GnRH antagonist AEZS-115 exhibited substantial antitumor activity in ovarian as well as endometrial cancer cell lines. However, this antitumor effect was not mediated by the tumoral GnRH receptors. To identify the mechanism of action of this compound, further research is warranted. Its in vitro antitumor activity makes AEZS-115 a promising candidate for in vivo studies of ovarian and endometrial cancer.

PI3K inhibitor D-116883 is effective in in vitro models of ovarian cancer

BACKGROUND

D-116883 (Aeterna Zentaris GmbH, Frankfurt, Germany) is an orally effective drug that acts via inhibition of phosphatidylinositol 3-kinase (PI3K). The PI3K/AKT signal transduction pathway is involved in ovarian cancer tumorigenesis. Phosphatase and Tensin homolog (PTEN) loss and other activating mutations frequently contribute to the activation of this pathway. We tested whether D-116883 exerts cytostatic effects in in vitro models of ovarian cancer and analyzed the induced programmed cell death.

MATERIALS AND METHODS

We evaluated the potency of D-116883 in four ovarian carcinoma cell lines with different cellular assays. The effects of D-116883 on cell proliferation was analysed by crystal-violet staining and tetrazolium salt [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; MTT] assay. The capacity for anchorage-independent growth was analyzed in two ovarian carcinoma cell lines without and with D-116883 addition by using the soft agar assay. Fluorescence activated cell sorting (FACS) cell cycle analyses were performed. Cells were incubated with multicaspase inhibitor benzyloxycarbonyl-val-ala-asp(OMe)-fluoromethylketone (zVAD) and inhibitor of necroptosis necrostatin.

RESULTS

Growth inhibition occurred in all ovarian carcinoma cell lines studied (A2780, A2780cis, OAW42 and SKOV3) in a micromolar range (IC(50)<1 μM). By using soft agar assay, a reduced capacity for anchorage-independent growth, a hallmark of tumor cells, caused by D-116883 was demonstrated. Cell cycle analyses showed that D-116883 dose-dependently increased apoptotic cells. Multicaspase inhibitor zVAD and inhibitor of necroptosis necrostatin did not abrogate the growth-inhibiting effect of the compound.

CONCLUSION

PI3K inhibitor D-116883 showed substantial cytotoxic effects in various in vitro models of ovarian cancer. Our results make D-116883 a good candidate for further ovarian cancer research including in vivo experiments.

Insight in schizophrenia-course and predictors during the acute treatment phase of patients suffering from a schizophrenia spectrum disorder

BACKGROUND

To analyse insight of illness during the course of inpatient treatment, and to identify influencing factors and predictors of insight.

METHODS

Insight into illness was examined in 399 patients using the item G12 of the Positive and Negative Syndrome Scale ("lack of insight and judgement"). Ratings of the PANSS, HAMD, UKU, GAF, SOFAS, SWN-K and Kemp's compliance scale were performed and examined regarding their potential association with insight. The item G12 was kept as an ordinal variable to compare insight between subgroups of patients.

RESULTS

Almost 70% of patients had deficits in their insight into illness at admission. A significant improvement of impairments of insight during the treatment (p<0.0001) was observed. At admission more severe positive and negative symptoms, worse functioning and worse adherence were significantly associated with poorer insight. Less depressive symptoms (p=0.0004), less suicidality (p=0.0218), suffering from multiple illness-episodes (p<0.0001) and worse adherence (p=0.0012) at admission were identified to be significant predictors of poor insight at discharge.

CONCLUSION

The revealed predictors might function as treatment targets in order to improve insight and with it outcome of schizophrenia.

Effects of three modifiers of glycolysis on ATP, lactate, hypoxia, and growth in human tumor cell lines in vivo

BACKGROUND

High pretreatment tumor lactate content is associated with poor outcome after fractionated irradiation in human squamous cell carcinoma (hSCC) xenografts. Therefore, decreasing lactate content might be a promising approach for increasing tumor radiosensitivity. As the basis for such experiments, the effects of the biochemical inhibitors pyruvate dehydrogenase kinase dichloroacetate (DCA), lactate dehydrogenase oxamate, and monocarboxylic acid transporter-1 α-cyano-4-hydroxycinnamate (CHC) on tumor micromilieu and growth were investigated.

MATERIALS AND METHODS

Oxygen consumption (OCR) and extracellular acidification rates (ECAR) were measured in FaDu and UT-SCC-5 hSCC in response to DCA in vitro. Mice bearing FaDu, UT-SCC-5, and WiDr colorectal adenocarcinoma received either DCA in drinking water or DCA injected twice a day, or CHC injected daily. WiDr was also treated daily with oxamate. FaDu and UT-SCC-5 were either excised 8 days after treatment for histology or tumor growth was monitored. WiDr tumors were excised at 8 mm. Effect of inhibitors on ATP, lactate, hypoxia, and Ki67 labeling index (LI) was evaluated.

RESULTS

DCA increased OCR and decreased ECAR in vitro. None of the treatments with inhibitors significantly changed lactate content, hypoxia levels, and Ki67 LI in the three tumor lines in vivo. ATP concentration significantly decreased after only daily twice injections of DCA in FaDu accompanied by a significant increase in necrotic fraction. Tumor growth was not affected by any of the treatments.

CONCLUSION

Overall, tumor micromilieu and tumor growth could not be changed by glycolysis modifiers in the three tumor cell lines in vivo. Further studies are necessary to explore the impact of metabolic targets on radiation response.

[Pelvic floor functions: from the beginning of the second phase of labor to the postpartum consultation]

Vaginal delivery can cause lesions of the various pelvic structures responsible for the mechanisms of continence. These lesions may perhaps be prevented in the future by measuring pressure generated during childbirth. Tear of the anal sphincter during childbirth is a marker of a global impairment of the urinary, ano-rectal and sexual pelvic functions in the short and medium term. Persistence of a defect of the anal sphincter is frequent in spite of immediate suture. The correlation between these defects and ano-rectal incontinence are not established in our experience. The quality of the contraction of the sphincter complex and pubo-rectal sling seems to play a more important role in ano-rectal continence after a traumatic childbirth.

The impact of agricultural intensification and land-use change on the European arable flora

The impact of crop management and agricultural land use on the threat status of plants adapted to arable habitats was analysed using data from Red Lists of vascular plants assessed by national experts from 29 European countries. There was a positive relationship between national wheat yields and the numbers of rare, threatened or recently extinct arable plant species in each country. Variance in the relative proportions of species in different threat categories was significantly explained using a combination of fertilizer and herbicide use, with a greater percentage of the variance partitioned to fertilizers. Specialist species adapted to individual crops, such as flax, are among the most threatened. These species have declined across Europe in response to a reduction in the area grown for the crops on which they rely. The increased use of agro-chemicals, especially in central and northwestern Europe, has selected against a larger group of species adapted to habitats with intermediate fertility. There is an urgent need to implement successful conservation strategies to arrest the decline of this functionally distinct and increasingly threatened component of the European flora.