Natural variation of male ornamental traits of the guppy, Poecilia reticulata

Male ornamental traits of the guppy, Poecilia reticulata, provide an outstanding example of natural variation in sex-linked male-advantageous traits that are shaped by both sexual and environmental selection. A substantial fraction of the underlying genes is known to be genetically linked to the sex-determining region on the differentiating Y-chromosome. Intercrosses between parental populations originating from geographically distant locations in East Trinidad and Cumaná (Venezuela) were used to study segregation of ornamental traits in male progeny. In addition, we performed backcrosses to compare segregation of ornaments in presence or absence of prominent traits linked to the Y-chromosome. Another backcross strategy involving XY females from the laboratory strain zebrinus maculatus allowed studying additive and dominant effects of alleles on two different Y-chromosomes on pattern formation. For genetic mapping, we have previously developed nuclear SNP markers linked to expressed genes, including several genes known to be important for pattern formation in other species. Of these candidate genes 15 were placed on 11 different linkage groups. Our phenotypic and genotypic analysis of progeny from mapping crosses and backcrosses suggests several genetic mechanisms that enhance natural variation, namely, additive effects of codominant alleles, suppressive actions of dominant alleles, and a complex interplay between sex-linked and autosomal cofactors.

Comprehensive cognitive neurological assessment in stroke

BACKGROUND

Cognitive syndromes (CS) after stroke may be important to measure and monitor for management and emerging therapies.

AIM

To incorporate known behavioral neurological and neuropsychiatric syndromes into a bedside cognitive assessment in patients with stroke.

METHODS

A validated cognitive examination (comprehensive cognitive neurological test in stroke, Coconuts) was administered during the first month of stroke presentation and analyzed according to five large-scale networks for cognition and correlated with neuropsychological tests. Validity testing of the test was performed for overall sensitivity, specificity, positive predictive value and negative predictive value to stroke in comparison with MRI diagnosis of stroke as well as discriminant validity, construct validity and inter-rater reliability.

RESULTS

Overall the sensitivity of the Coconuts scale was 91% and specificity 35%, PPV 88% and NPV 41% vs stroke lesions using MRI. Cognitive syndrome frequencies: frontal network syndrome frequency was 908/1796 (51%), left hemisphere network syndrome frequency was 646/1796 (36%), right hemisphere network included 275/1796 (15.3%), occipitotemporal network for complex visual processing 107/1796 (6%), the hippocampal limbic network for amnesias and emotional disorders 397/1796 (22%) and miscellaneous network syndromes 481/1796 (27%).

CONCLUSION

The Coconuts is a valid and practical test of a comprehensive array of known behavioral neurological and neuropsychiatric syndromes in patients with stroke.

Paclitaxel and carboplatin vs gemcitabine and vinorelbine in patients with adeno- or undifferentiated carcinoma of unknown primary: a randomised prospective phase II trial

Platinum/taxane combinations are widely used in patients with carcinoma of unknown primary (CUP), yielding response rates of 30% and median overall survival of 9-11 months in selected patients. Yet these combinations have not been subject to a randomised trial to overcome selection bias, a major problem in CUP. We randomised 92 patients to either paclitaxel/carboplatin (arm A) or the non-platinum non-taxane regimen gemcitabine/vinorelbine (arm B). The primary endpoint was rate of practicability as defined: application of >or=2 cycles of therapy (1) with a maximal delay of 1 week (2) and survival of >or=8 months (3). Practicability was shown in 52.4% (95% CI 36-68%) in arm A and in 42.2% (95% CI 28-58%) in arm B, respectively. The median overall survival, 1-year survival -rate and response rate of patients treated in arm A was 11.0 months, 38, and 23.8%, arm B 7.0 months, 29, and 20%. In conclusion, the paclitaxel/carboplatin regimen showed clinically meaningful activity in this randomised trial (Clinical trial registration number 219, 'Deutsches KrebsStudienRegister', German Cancer Society.)

Highly efficient optically pumped vertical-emitting semiconductor laser with more than 20 W average output power in a fundamental transverse mode

We have demonstrated an optically pumped vertical-external-cavity surface-emitting laser (OP-VECSEL) generating more than 20 W of cw output power in a fundamental transverse mode (M2 approximately 1.1) at 960 nm. The laser is highly efficient with a slope efficiency of 49%, a pump threshold of 4.4 W, and an overall optical-to-optical efficiency of 43%.

Growth parameter optimization for fast quantum dot SESAMs

Semiconductor saturable absorber mirrors (SESAMs) using quantum dot (QD) absorbers exhibit a larger design freedom than standard quantum well absorbers. The additional parameter of the dot density in combination with the field enhancement allows for an independent control of saturation fluence and modulation depth. We present the first detailed study of the effect of QD growth parameters and post growth annealing on the macroscopic optical SESAM parameters, measuring both nonlinear reflectivity and recombination dynamics. We studied a set of self-assembled InAs QD-SESAMs optimized for an operation wavelength around 960 nm with varying dot density and growth temperature. We confirm that the modulation depth is controlled by the dot density. We present design guidelines for QD-SESAMs with low saturation fluence and fast recovery, which are for example important for modelocking of vertical external cavity surface emitting lasers (VECSELs).

Hypophosphataemia at a large academic hospital in South Africa

Aim:

The aim of this study was to determine the most common causes of hypophosphataemia (⩽0.5 mmol/l) in a hospital population in order to identify patient groups at risk of developing the condition.

Methods:

The study was conducted at Tygerberg Hospital, a tertiary care centre in the Western Cape, South Africa. All patients identified with a phosphate level ⩽0.5 mmol/l during an 18-month period were included in the study. Medical records of these patients were reviewed.

Results:

Of all the requests received for serum phosphate determination by the laboratory, 2% (861 out of 45 394 requests) were ⩽0.5 mmol/l. Thirty per cent (30%; n = 189) of the patients in the study population died during their hospital stay. Most (45%; n = 278) of the patients with low phosphate levels occurred in an intensive care setting, whereas 10% (n = 63) were most likely due to refeeding, and 6% (n = 35) had neoplastic disease. Sepsis was implicated as a contributing factor in 26% (n = 162).

Conclusion:

Severe hypophosphataemia is associated with a very high mortality (30%, n = 189). Patients with a high risk of developing hypophosphataemia include those in an intensive care unit (ICU), patients suffering from neoplastic diseases, possible refeeding syndrome and septic patients. Regular phosphate determination is recommended in these patients to facilitate early diagnosis of hypophosphataemia.

Treatment of reduced bone density with ibandronate in dialysis patients

Bisphosphonates inhibit bone resorption and are widely used to treat osteolytic metastases and osteoporosis. Renal osteodystrophy patients have continuous bone loss due to chronically elevated parathyroid hormone (PTH). In this open-label study, ibandronate was evaluated for the treatment of reduced bone density in renal osteodystrophy. Patients (n=16) with end-stage renal disease (ESRD) and regular hemodialysis schedules were recruited. All patients had low bone mineral density (BMD; lumbar spine T-score <-1.0) and elevated PTH levels (>2-fold higher than normal). Patients received ibandronate 2 mg every 4 weeks for 48 weeks. Serum levels of markers of bone turnover, calcium, phosphate and magnesium were determined (week 0 [prior to treatment] vs. at week 48). BMD (n=11) increased significantly from 88.94 +/- 31.68 mg/mL calcium hydroxylapatite (CaHA) to 93.51 +/- 35.36 mg/mL CaHA (p=0.032). T-scores increased significantly from -3.08 +/- 1.11 to -2.78 +/- 1.27 (p<0.01). The mean PTH level initially increased before dropping to 18.99 pmol/L at week 48 (7.99% decrease vs. week 0; not significant). Bone turnover markers decreased, whereas calcium and magnesium levels remained stable and within normal ranges. Phosphate levels were variable throughout the study. Two patients did not complete the study, and 3 patients died due to concomitant cardiovascular disease. Calcitriol dosage increased from 1.5 to 1.83 microg/week. In patients with renal osteodystrophy and ESRD, ibandronate significantly increased BMD and decreased bone turnover.

[Rare cause of recurring necrotising pancreatitis]

BACKGROUND

Necrotising pancreatitis may develop as a consequence of pancreatic duct obstruction by stones, tumors or in the presence of a pancreas divisum. Alcohol and nicotine are regarded as risk factors for the disease becoming chronic.

PATIENT AND COURSE OF THE DISEASE

A 63-year-old female patient with suspected cystadenocarcinoma of the pancreas tail, which was resolved as a pancreatic pseudocyst, was treated for recurrent pancreatitis for 2 years. A tumor in the pancreas head was only detected on a follow-up CT after resection of a complicating liver abscess. In retrospect, progressive pancreatic duct anomalies were visible on previous scans. Partial duodenopancreatectomy confirmed the presence of a pancreas head carcinoma.

CONCLUSION

Continuous critical re-evaluation of all potential causes of pancreatitis including rare conditions, such as a tumor, is required particularly if pancreatitis recurs over a long period. Re-evaluation of studies over time and of findings apart from the actual main focus of the complication, in this case pancreatitis of the pancreas tail, may help to detect the underlying disease instead of just treating the consequences.

[Lymphedema in patients with breast cancer--a consensus regarding diagnostics and therapy in patients with postoperative lymphedema after primary breast cancer]

Secondary lymphedema is one of the most frequent long-term side effects affecting up to 30% of all breast cancer patients after local surgical and radiation treatment. Destruction of the lymphatic system causes a progressive and chronic condition with functional impairments and disabilities limiting patients in their daily activities and involving nearly all aspects of their quality of life. Also, problems in the occupational area may be caused by lymphedema. The need for improving oncological management for early diagnosis and referral for effective treatment of lymphedema is a major goal of breast cancer heath care while survival improves.

METHOD

A systematic consensus process was performed involving all relevant partners and providers of lymphedema health care to develop a practical documentation concept and make recommendations according to the evidence of clinical studies and currently available guidelines.

RESULTS

A practical concept of documentation with defined assessment points was developed for evaluation and monitoring of lymphedema, which included the assessment of quality of life parameters with recognised instruments by the patient themselves. Consensus recommendations for the postoperative management, prevention, treatment and follow-up of breast cancer patients along a clinical algorithm for in- and outpatient care were finalized.

CONCLUSION

With improved survival, long-term side effects with major impact on quality of life become a most important end point criteria of oncological treatment. The clearly defined documentation concept and the comprehensive recommendations for lymphedema management may assist clinicians and patients to make timely decisions about in- and outpatient health care practice to optimize the interface between acute medicine and rehabilitation. Patients' compliance with treatment and prevention routines will be as important as ensuring the continuity of care. A longitudinal prospective study evaluating the effectiveness and efficacy of the consensus recommendation is currently being implemented.

From single cells to tissue architecture-a bottom-up approach to modelling the spatio-temporal organisation of complex multi-cellular systems

Collective phenomena in multi-cellular assemblies can be approached on different levels of complexity. Here, we discuss a number of mathematical models which consider the dynamics of each individual cell, so-called agent-based or individual-based models (IBMs). As a special feature, these models allow to account for intracellular decision processes which are triggered by biomechanical cell-cell or cell-matrix interactions. We discuss their impact on the growth and homeostasis of multi-cellular systems as simulated by lattice-free models. Our results demonstrate that cell polarisation subsequent to cell-cell contact formation can be a source of stability in epithelial monolayers. Stroma contact-dependent regulation of tumour cell proliferation and migration is shown to result in invasion dynamics in accordance with the migrating cancer stem cell hypothesis. However, we demonstrate that different regulation mechanisms can equally well comply with present experimental results. Thus, we suggest a panel of experimental studies for the in-depth validation of the model assumptions.

Chronic autoimmune thyroiditis (Hashimoto's thyroiditis) in patients with MALT lymphoma

BACKGROUND

Autoimmune diseases have been implicated in the genesis of MALT lymphoma of various localizations. The development of thyroidal MALT lymphoma has been described as an adverse event in patients suffering from long-standing chronic autoimmune thyroiditis (CAT, Hashimoto's thyroiditis). The percentage and possible association between CAT and extrathyroidal MALT lymphoma, however, have not been assessed so far.

PATIENTS AND METHODS

A retrospective analysis of 80 patients with MALT lymphoma diagnosed and treated at our institution identified a total of 13 patients (16%) with MALT lymphoma suffering from an underlying CAT. Patient characteristics including site of disease, stage, genetic changes and clinical course were assessed and evaluated.

RESULTS

In total, 10 patients were female and 3 male, with the median age being 57 years (range: 31-80). Four patients suffered from thyroidal lymphoma and nine patients had extrathyroidal lymphoma (four gastric, two orbital, one small intestinal and two salivary gland lymphomas). Three patients had a long-standing history of CAT at diagnosis of MALT lymphoma, while CAT was discovered during staging and clinical work-up of MALT lymphoma in the remaining 10 patients. All 13 patients had localized disease, i.e. stage I or II. Only one of the four patients with gastric MALT lymphoma responded to antibiotic treatment against Helicobacter pylori infection. Genetic aberrations were detected in four patients, two of whom had a t(11;18)(q21;q21) translocation, one patient had trisomies 3 and 18 and one had trisomy 18.

CONCLUSION

Our findings suggest that CAT is found in patients with not only thyroidal but also nonthyroidal MALT lymphoma. While the nature of our data does not allow for delineation of a direct association between CAT and development of extrathyroidal MALT lymphoma, further prospective studies on this issue are warranted.

Pathology and clinical course of MALT lymphoma with plasmacytic differentiation

BACKGROUND

The feature of plasmacytic differentiation (PCD) is present in up to 30% of patients diagnosed with mucosa-associated lymphoid tissue (MALT) lymphoma. To date, the influence of PCD on the clinical course of MALT lymphoma has not been assessed.

PATIENTS AND METHODS

Therefore, we have retrospectively analysed the clinical characteristics and the course of the disease in 34 (25%) patients with PCD as compared with 101 (75%) MALT lymphoma patients without this histological feature.

RESULTS

Patients with PCD had significantly more extragastric lymphomas [28 of 34 (82%) versus 54 of 101 (53%), P = 0.003] and a significantly lower rate of t(11;18) [2 of 26 (8%) versus 22 of 72 (31%), P = 0.02]. There was no significant difference of age at diagnosis (62 versus 64 years, P = 0.64), relapse rate (48% versus 37%, P = 0.27), estimated median time to progression (43 versus 65 months, P = 0.14), monoclonal gammopathy (50% versus 44%, P = 0.63), t(14;18) involving IGH/MALT 1 (11% versus 8%, P = 0.68), trisomy 3 (31% versus 27%, P = 0.69), trisomy 18 (8% versus 10%, P = 0.74) and the presence of autoimmune diseases between both groups (53% versus 37%, P = 0.09).

CONCLUSION

In conclusion, we found that PCD is predominantly found in extragastric MALT lymphoma but has no significant impact on clinical course and prognosis.