Larval morphology of Metaphycus flavus and its role in host attachment and larval cannibalism.

Metaphycus flavus (Howard) (Hymenoptera: Encyrtidae) is a facultatively gregarious endoparasitoid of soft scales (Hemiptera: Coccidae). When it develops in superparasitised hosts, the larvae often attack and consume brood mates six or more days post oviposition. Under our laboratory conditions (25±1°C and 14 hours of light followed by 18±1°C and ten hours of darkness in 50-70% R.H.), M. flavus eggs hatched three days after oviposition. Measurements of the mandibles and tentorium indicate there are four larval instars, and M. flavus reaches the fourth instar by day six post oviposition, and pupates on day eight. Thus, cannibalism among M. flavus larvae occurs during the fourth instar. During this instar, M. flavus larvae separate from their attachment to the scale cuticle, to which they were tethered by a respiratory structure during the previous three larval instars. Once detached, they are free to move within the scale, which increases the probability of larval encounters and aggressive behaviours. Moreover, the mandibles of the fourth instar are better adapted for fighting than are those of the first three larval instars, since they are larger and more sclerotized. The cranium and mouthparts of M. flavus have four different types of sensory organs, some of which are almost certainly olfactory, an unexpected function for a larva that presumably is surrounded by an aqueous medium where gustatory sensilla would seem to be more appropriate. The cranium also bears two pairs of what appear to be secretory pores.

Regulatory T cells in peripheral blood, lymph node, and thyroid tissue in patients with medullary thyroid carcinoma.

BACKGROUND: Immunological response of the human body is controlled by the suppressive characteristics of regulatory T cells (Tregs). In various diseases a change in the number of Tregs is evident. For example, whereas Tregs are reduced in auto-immunological processes, an increase of Tregs is found with various malignant tumors. Regarding medullary thyroid carcinoma (MTC) no such studies have been performed to date. METHODS: Expression of CD4 and CD25 in CD45+ leukocytes from blood and lymph nodes was studied by flow cytometry in patients with MTC and patients with benign goiter. We also examined the marker forkhead box P3 (FoxP3), an intracellular transcription factor, which is supposed to be the most specific marker for Tregs. Immunohistochemical staining for FoxP3 was performed on lymph node and thyroid tissue. RESULTS: The number of FoxP3+ lymphocytes in peripheral blood was significantly higher in patients with MTC than in controls (p = 0.02). This result was confirmed immunohistochemically in lymph node and thyroid tissue, as well as in carcinoma tissue. No difference in CD4+CD25+ lymphocytes was observed between the two groups. After clinical staging (International Union against Cancer-UICC-stages) of MTC patients, triplication of FoxP3+ lymphocytes could be observed from MTC < UICC II to MTC > UICC II. CONCLUSIONS: An increase of FoxP3+ lymphocytes could be shown in peripheral blood of patients with MTC but not in patients with benign goiter; this increase also correlates with findings in lymph nodes and thyroid gland. The number of FoxP3+ cells correlated with the patients' prognosis. Therefore, FoxP3+ lymphocytes are a good diagnostic criterion for malignancy in patients with medullary thyroid carcinoma, and their presence at staging may influence therapeutic decisions.

Determining Protease Substrates Within a Complex Protein Background Using the PROtein TOpography and Migration Analysis Platform (PROTOMAP).

The PROtein TOpography and Migration Analysis Platform (PROTOMAP) approach is a degradomics technique used to determine protease substrates within complex protein backgrounds. The method involves protein separation according to protein relative mobility, using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Gel lanes are then sliced into horizontal sections, and in-gel trypsin digestion performed for each gel slice. Extracted peptides and corresponding proteins are identified using liquid chromatography-tandem mass spectrometry and bioinformatics. Results are compiled in silico to generate a peptograph for every identified protein, being a pictorial representation of sodium dodecyl sulfate polyacrylamide gel electrophoresis. Proteins shown by their peptograph to have migrated further through the gel (i.e., to a lower gel slice) in the lane containing the active protease(s) of interest, as compared to the control, are deemed putative protease substrates. PROTOMAP has broad applicability to a range of experimental conditions and protein pools. Coupling this with its simple and robust methodology, the PROTOMAP approach has emerged as a valuable tool with which to determine protease substrates in complex systems.

ConStruct: a tool for thermodynamic controlled prediction of conserved secondary structure.

A tool for prediction of conserved secondary structure of a set of homologous single-stranded RNAs is presented. For each RNA of the set the structure distribution is calculated and stored in a base pair probability matrix. Gaps, resulting from a multiple sequence alignment of the RNA set, are introduced into the individual probability matrices. These 'aligned' probability matrices are summed up to give a consensus probability matrix emphasizing the conserved structural elements of the RNA set. Because the multiple sequence alignment is independent of any structural constraints, such an alignment may result in introduction of gaps into the homologous probability matrices that disrupt a common consensus structure. By use of its graphical user interface the presented tool allows the removal of such misalignments, which are easily recognized, from the individual probability matrices by optimizing the sequence alignment with respect to a structural alignment. From the consensus probability matrix a consensus structure is extracted, which is viewable in three different graphical representations. The functionality of the tool is demonstrated using a small set of U7 RNAs, which are involved in 3'-end processing of histone mRNA precursors. Supplementary Material lists further results obtained. Advantages and drawbacks of the tool are discussed in comparison to several other algorithms.

Progressive deterioration of endocrine function after intraportal but not kidney subcapsular rat islet transplantation.

In inbred streptozocin-induced diabetic rats, the long-term function of different endocrine pancreatic isografts was compared. Isolated islets transplanted into the portal vein showed a progressive deterioration of function over time. In contrast, islets under the kidney capsule sustained a constant long-term function controlling all clinical signs of diabetes. Recipients of kidney subcapsular islets displayed normal growth rate, peripheral serum glucose and insulin levels, and metabolic parameters. However, their functional reserve was markedly reduced as revealed by diminished glucose tolerance and reduced insulin-secreting capacity after an intravenous glucose challenge. Vascularized whole-organ pancreatic grafts with portal venous drainage led to complete normalization of all parameters determined in this study. This study showed that the long-term function of islets transplanted under the kidney capsule is superior compared with islets transplanted into the portal vein.

Thermodynamic prediction of conserved secondary structure: application to the RRE element of HIV, the tRNA-like element of CMV and the mRNA of prion protein.

An algorithm for prediction of conserved secondary structure of single-stranded RNA is presented. For each RNA of a set of homologous RNAs optimal and suboptimal secondary structures are calculated and stored in a base-pair probability matrix. A multiple sequence alignment is performed for the set of RNAs. The resulting gaps are introduced into the individual probability matrices. These homologous probability matrices are summed to give a consensus probability matrix emphasizing the conserved secondary structure elements of the RNA set. Thus the algorithm combines the advantages of thermodynamic structure prediction by energy minimization with the information obtained from phylogenetic alignment of sequences. The algorithm is applied to three examples. The REV-responsive element of HIV, the structure of which is well known from the literature, was chosen to test the algorithm. The second example is the 3' terminal segment of genomic single-stranded RNAs of cucumber mosaic viruses; a structure similar to that of the related brome mosaic virus was expected and was confirmed. The third example is the prion-protein mRNA from different organisms; the structure of this mRNA is not known. By application of the algorithm highly conserved hairpins were found in the prion-protein mRNA.

Significance of portal venous drainage after whole-organ pancreas transplantation for endocrine graft function and prevention of diabetic nephropathy.

The significance of portal venous drainage after whole-pancreas transplantation both for metabolic control and development of diabetic nephropathy was investigated. Streptozotocin-diabetic inbred LEW rats received a duct-ligated pancreas graft with either systemic or portal venous drainage and were followed for up to one year. Normal and untreated diabetic rats (n=18 in each group) served as controls. Irrespective of the route of venous drainage pancreas transplants normalized the diabetic polyuria, polyphagia, and polydipsia. Growth rates and general health did not differ from normal rats. Pancreas transplantation with portal venous drainage furthermore normalized nonfasting blood glucose and peripheral insulin levels, and intravenous glucose tolerance. Pancreas transplantation with systemic venous drainage, however, was associated with peripheral hyperinsulinemia, slightly elevated nonfasting blood glucose levels, and supranormal K-values in intravenous glucose tolerance tests. Though portal venous drainage was associated with better metabolic control than systemic venous drainage, both techniques of pancreas transplantation proved equally effective to prevent the development of diabetic glomerular membrane thickening determined 6 and 12 months posttransplant.

Successful outcome of acute graft-versus-host disease in a liver allograft recipient by withdrawal of immunosuppression.

BACKGROUND: Graft-versus-host disease (GVHD) after liver transplantation is uncommon, and the outcome is almost always fatal. Since 1987, about 30 cases have been described, and patient survival is mostly exceptional. METHODS: A 29-year-old man underwent retransplantation due to chronic cholestatic syndrome, 5 years after his first liver transplantation. Indication for the first liver transplantation was acute liver failure caused by exsiccosis. After the second transplantation, the patient had an initially uneventful course, developing thrombocytopenia at day 21 followed by skin rash and septic complications. Diagnosis of acute GVHD was made by using serological techniques for HLA-A and HLA-DRB and subsequently by fluorogenic sequence-specific primed polymerase chain reaction. In addition, donor lymphocytes were marked by immunohistochemical methods via biopsies of the skin. Immunosuppressive therapy was withdrawn to allow the patient's own immune system to eliminate donor cells. RESULTS: By withdrawing the immunosuppressive therapy, clinical and morphological signs of GVHD vanished. The patient is doing well without recurrence 13 months after transplantation. CONCLUSION: Withdrawal of immunosuppressive therapy is a promising approach in the treatment of acute GVHD to allow the patient's immune system to reconstitute itself, reject offending lymphocytes, and avoid lethal septic complications.

Selfish element maintains sex in natural populations of a parasitoid wasp.

Genomic conflicts between heritable elements with different modes of inheritance are important in the maintenance of sex and in the evolution of sex ratio. Generally, we expect sexual populations to exhibit a 1:1 sex ratio. However, because of their biology, parasitoid wasps often exhibit a female-biased sex ratio. Sex-ratio distorters can further alter this optimum, sometimes leading to the complete loss of sexual reproduction. In the parasitoid wasp Trichogramma kaykai ca. 4-26% of females in field populations are infected with a bacterial sex-ratio distorter, Wolbachia, allowing virgin mothers to produce daughters. In some micro-Hymenoptera these infections have led to the complete loss of sex, but in field populations of T. kaykai the proportion of individuals infected remains relatively stable. We tested several hypotheses to explain this low infection level, including inefficient and horizontal transmission of Wolbachia, suppressor genes negating the effect of Wolbachia and the presence of male-biasing sex-ratio distorters. Here, a male-biasing sex-ratio distorter, a parasitic B chromosome, causing females to produce only sons, keeps the frequency of Wolbachia low. The male-biasing factor of T. kaykai is the second known case of a B chromosome manipulating the reproduction of a parasitoid wasp.

Natural interspecific and intraspecific horizontal transfer of parthenogenesis-inducing Wolbachia in Trichogramma wasps.

The intracellular bacterium Wolbachia is one of the most common symbionts in arthropods and, because of its manipulative effects on host reproduction, is assumed to be an important factor in several evolutionary processes. These bacteria are mainly vertically transmitted from mother to daughter through the egg cytoplasm, and horizontal transmission is generally assumed to be rare. Here, we show natural inter- and intraspecific horizontal transfer of parthenogenesis-inducing Wolbachia between parasitoid wasps of the genus Trichogramma. Horizontal transfer was observed when infected and uninfected larvae shared the same host egg. This is the first report, to our knowledge, on interspecific horizontal transfer of Wolbachia between closely related sympatric species. Some originally uninfected immature wasps acquired Wolbachia while inside the host egg, but not all of these newly infected females exhibited the parthenogenesis phenotype. In general, intraspecific horizontal transfer was more successful than interspecific transfer. Wolbachia underwent vertical transmission in the new species but the infection tended to be lost within several generations. Our results have important implications for understanding the evolution of Wolbachia-host associations.

Patient survival with liver metastases from colorectal cancer--a district hospital experience.

In a retrospective review of 301 newly diagnosed tumours of the colon and rectum, 61 patients (20%) presented with liver metastases. The mean survival for this group was 7.4 months. Five patients with solitary metastases were found who may have been helped by further surgery. There was a 20% operative mortality. No significant association between the grade, differentiation, lymph node status or venous invasion of the primary lesion was demonstrated. Operative palliative resection of the primary lesion did not improve survival. These results confirm the poor prognosis for patients with liver metastases, justifying all efforts into the earlier detection and prevention of colorectal carcinoma.

[Perfusion parameters in MRI diagnosis of pancreas transplants]. / Perfusionsparameter in der MRT-Diagnostik von Pankreastransplantaten.

PURPOSE: Evaluation of the role of perfusion parameters in the detection of circulatory disturbance and chronic rejection in patients after pancreas transplantation. MATERIALS AND METHODS: 70 examinations of 39 patients after pancreas transplantation were performed. Using a dynamic gadolinium-enhanced Turbo-FLASH-sequence, we evaluated the perfusion parameters in a group of patients with chronic rejection, with circulatory disturbance, and in a control group with normal organ function. RESULTS: There were statistically significant differences of the perfusion parameters in patients with chronic rejection and circulatory disturbance compared to the control group. CONCLUSION: Dynamic MRI can help detect patients with chronic rejection and circulatory disturbance and should therefore be part of the routine follow-up in patients after pancreas transplantation.

Update on liver transplantation using cyclosporine.

After the introduction of cyclosporine into liver transplantation in 1983, 1-year patient survival more than doubled. Later, with the improved microemulsified formulation of cyclosporine (Neoral) more stable pharmacokinetics were achieved. Today, C(2) monitoring of cyclosporine blood levels allows a more accurate estimation of the area under the concentration-versus-time curve as the single best indicator of cyclosporine exposure. As a consequence, with better control of side effects as well as desired effects the results of cyclosporine in liver transplantation have been further improved. The introduction of mycophenolate mofetil and basiliximab/daclizumab combination therapy has provided new options for the prevention of allograft rejection. The safety profile of individual immunosuppressive regimens comes more into focus since acute allograft rejection may be controlled successfully with competing strategies. As the focus in liver transplantation is shifting toward greatly improved long-term results, late posttransplant mortality with a functioning graft is a major concern. Prevention of long-term complications associated with highly effective immunosuppressants--posttransplant lymphoproliferative disease, cytomegalovirus infection, diabetes, hypertension, and hyperlipidemia-gains importance. Technical advances in living-related and cadaveric split-liver transplantation have lead to increasing use of segmental liver transplantation with the need to consider the effects of immunosuppression on liver regeneration and metabolism. The individualized orchestration of immunosuppression taking into account the underlying liver disease as well as other individual predispositions remains a future challenge.

Use of collagen implant for posterior rectopexy in complete rectal prolapse: preliminary communication.

A variety of materials has been used for perirectal implantation in the treatment of complete rectal prolapse. A new material (Zenoderm) prepared from porcine corium has been used successfully in 4 patients. The material proved to be inert, biologically non-irritant, pliable, workable and strong.

[Living kidney transplantation. A comparison of Scandinavian countries and Germany]. / Lebendnierenspende. Ein Vergleich zwischen den skandinavischen Ländern und Deutschland.

The discussion of compensating for shortages of cadaveric donation with increased living donation often reveals differences between the Scandinavian countries and Germany. Possible adoption of Scandinavian structures to improve the rate of living donations in Germany warrants analysis of the actual differences between these two regions. Close examination reveals that significantly higher rates of living donation are achieved only in Sweden and Norway. In Norway, a frequently postulated negative effect on cadaveric donation due to very high rates of living donation could not be confirmed. In contrast to Germany and as a consequence of Norwegian geography, kidney transplantation has been regarded in Norway as the first-line therapy for endstage renal disease for more than 35 years. Living donation has since been actively pursued and is traditionally the transplantation of first choice. In Germany, living donation is still regarded as the second choice after cadaveric donation, due to legal regulations. Significant improvements in living donation frequencies could be achieved there by adopting the active Norwegian approach to living donor identification.

Tris(1,10-phenanthroline-N,N')chromium(III) triperchlorate hydrate.

The structure of the cation in [Cr(C(12)H(8)N(2))(3)](ClO(4))(3).H(2)O consists of the Cr atom bonded to the N atoms of the three 1,10-phenanthroline (phen) ligands, resulting in a distorted octahedral arrangement with the six Cr-N distances ranging from 2.040 (4) to 2.055 (4) A. One of the perchlorate anions is disordered and is located around two special positions.

A simple numerical procedure for estimating nonlinear uncertainty propagation.

Accurately determining the effect of the propagation of uncertainty in nonlinear applications can be awkward and difficult. The Monte Carlo approach requires statistically significant numbers of function evaluations (typically 10(5) or more) and analytical methods are intractable for all but the simplest cases. This paper derives and demonstrates a method to estimate the propagation of uncertainty in nonlinear cases by representing the function in a piecewise fashion with straight line segments. The probability density function of the result can be calculated from the transformation of the line segments. The mean and confidence intervals of the result can then be calculated from the probability density function. For the special case of a normal distribution in the independent variable, calculation of the mean and confidence intervals requires evaluation of only the error function (erf). A simple example is presented to demonstrate the technique. Variations on the basic approach are presented and discussed.

A modular approach to linear uncertainty analysis.

This paper introduces a methodology to simplify the uncertainty analysis of large-scale problems where many outputs and/or inputs are of interest. The modular uncertainty technique presented here can be utilized to analyze the results spanning a wide range of engineering problems with constant sensitivities within parameter uncertainty bounds. The proposed modular approach provides the same results as the traditional propagation of errors methodology with fewer conceptual steps allowing for a relatively straightforward implementation of a comprehensive uncertainty analysis effort. The structure of the modular technique allows easy integration into most experimental/modeling programs or data acquisition systems. The proposed methodology also provides correlation information between all outputs, thus providing information not easily obtained using the traditional uncertainty process based on analyzing one data reduction equation (DRE)/model at a time. Finally, the paper presents a straightforward methodology to obtain the covariance matrix for the input variables using uncorrelated elemental sources of systematic uncertainties along with uncorrelated sources corresponding to random uncertainties.