Bridging trees for posterior inference on ancestral recombination graphs.

We present a new Markov chain Monte Carlo algorithm, implemented in the software Arbores, for inferring the history of a sample of DNA sequences. Our principal innovation is a bridging procedure, previously applied only for simple stochastic processes, in which the local computations within a bridge can proceed independently of the rest of the DNA sequence, facilitating large-scale parallelization.

Did Adult Diurnal Activity Influence the Evolution of Wing Morphology in Opoptera Butterflies?

The butterfly genus Opoptera includes eight species, three of which have diurnal habits while the others are crepuscular (the usual activity period for members of the tribe Brassolini). Although never measured in the field, it is presumed that diurnal Opoptera species potentially spend more time flying than their crepuscular relatives. If a shift to diurnal habits potentially leads to a higher level of activity and energy expenditure during flight, then selection should operate on increased aerodynamic and energetic efficiency, leading to changes in wing shape. Accordingly, we ask whether diurnal habits have influenced the evolution of wing morphology in Opoptera. Using phylogenetically independent contrasts and Wilcoxon rank sum tests, we confirmed our expectation that the wings of diurnal species have higher aspect ratios (ARs) and lower wing centroids (WCs) than crepuscular congeners. These wing shape characteristics are known to promote energy efficiency during flight. Three Opoptera wing morphotypes established a priori significantly differed in AR and WC values. The crepuscular, cloud forest dweller Opoptera staudingeri (Godman & Salvin) was exceptional in having an extended forewing tip and the highest AR and lowest WC within Opoptera, possibly to facilitate flight in a cooler environment. Our study is the first to investigate how butterfly wing morphology might evolve as a response to a behavioral shift in adult time of activity.

A pair of twins born after maternal exposure to leflunomide.

Leflunomide is a drug used in rheumatoid arthritis with teratogenic and fetotoxic effects. Clinical data on human pregnancies are limited to a few case reports without detailed information whether the mothers did have a washout procedure as suggested by the manufacturer or what type of malformation the offspring showed. We report on a set of twins born after maternal exposure to leflunomide who had a largely normal neonatal outcome, providing information about the washout procedure and the blood level of the active metabolite.

[Adjuvant hormone therapy for prostate cancer after local treatment in the context of evidence based medicine]. / Die adjuvante Hormontherapie des Prostatakarzinoms nach lokaler Therapie im Kontext der evidenzbasierten Medizin.

At present, prostate cancer is the most frequent malignant disease in German men. The aims of adjuvant hormone treatment are to increase progression free survival and improve cure rate. Risk factors for progression are a Gleason score > or =8, large tumor volumes, a high preoperative PSA (>15-29 ng/ml), penetration of the capsule, positive margins and lymph node metastasis. The type of hormone therapy (LHRH-nnalogues, non-steroidal anti-androgens, surgical castration) should be discussed with the patient. Bicalutamide seems to be an alternative for younger patients due to the lack of side effects of testosterone suppression.

[The role of PSA in diagnosis of prostate cancer and its recurrence]. / Stellenwert des prostataspezifischen Antigens (PSA) in der Primär- und Rezidivdiagnostik des Prostatakarzinoms.

Prostate specific antigen is the most important tumor marker of prostate cancer. PSA, in conjunction with digital rectal examination, is the first-line clinical tool for detection of prostate cancer. To improve its specificity PSA-density, PSA-ratio (fPSA/tPSA), PSA-velocity, and complexed PSA have been introduced into clinical praxis. The treatment of lower stage disease in younger men has resulted in a longer period of post-treatment cancer surveillance. Biochemical recurrence is an early indicator for clinical disease recurrence. PSA doubling time allows to distinguish between local and systemic progression and is also a valid predictor for distant metastasis and death of disease.

[The aftercare principle for metastasizing prostate cancer. Few diagnostics, much support]. / Das Nachsorgeprinzip beim metastasierten Prostatakarzinom - Wenig Diagnostik, viel Support.

For advanced prostate cancer - not including intermittent strategies - the patient is in continual treatment. The effect of the therapy must be controlled so that its failure can be determined as soon as possible and a new regimen started. As in most cases the progression of the disease can not be stopped, the aim of the therapy is to provide the patient with the best possible quality of life. In order to carry out therapy, if possible in the patient's usual environment, supportive therapies should be used, such as compensation for anaemia or pain therapy as required. Skeletal complications can be prophylactically treated by the use of biphosphonates.

[Chemotherapy of the hormone-refractory prostate cancer]. / Chemotherapie des hormonrefraktären Prostatakarzinoms.

The scepticism dominating the chemotherapy of the hormone-refractory prostate cancer (HRPC) has been replaced by a wave of enthusiasm. Phase II studies with taxane-containing combination therapies could achieve high response rate in some cases, and HRPC can not longer be deemed resistant to chemotherapy. It remains to be seen whether the combinations offer a survival advantage. This will be tested in phase III studies. Palliative chemotherapy should be considered in patients with HRPC if the initial hormone therapy was effective for a short time only and after several hormone therapies have been completed. Since chemotherapy is not yet an established standard therapy of HRPC, patients should be, if possible, included in clinical studies.

Long-term results after surgical correction of atrioventricular septal defects.

OBJECTIVE: Review of the results of surgical correction of atrioventricular septal defects (AVSD), identification of risk factors for mortality and failure of left AV valve repair and determination of the impact of cleft closure on postoperative AV valve function. METHODS: Between 1975 and 1995, 121 consecutive patients (55 males, 66 females) underwent surgery for biventricular correction of AVSD with a median age of 1.2 years and a median weight of 7.6 kg. Sixty-five patients had a complete AVSD, 17 patients an intermediate type, and 39 patients a partial AVSD. The left AV valve (MV) cleft was closed in 53 patients (43.8%). The mean follow-up time is 7.2+/-4.6 years. RESULTS: Actuarial survival of the whole group after 1 year was 80%, after 10 and 20 years 78 and 65%, respectively. There were 18 early deaths (7-day mortality, 10.7%; 30-day mortality, 14.9%) and eight late deaths. In a univariate analysis, risk factors for early or late death were diagnosis of complete AVSD (P=0.006), no cleft closure (P=0.024), postoperative complications (P<0.0001), age <1.2 years (P=0.017), weight <7.6 kg (P=0.002), PA/Ao pressure ratio >0.7 (P<0.0001), and ECC time >110 min (P=0.002). In the multivariate analysis, postoperative complications (P=0.003) and PA/Ao pressure ratio >0.7 (P=0.001) had parallel effects on the postoperative risk for mortality. Moderate or severe MV regurgitation was present in six patients (6.0%) in the first evaluation after discharge and in 20 patients (20.4%) in the most recent postoperative control. There were 25 reoperations in 17 patients, of which 15 had to be performed for MV regurgitation and two for MV stenosis. Freedom from reoperation was 91% at 1 year, 79% at 10 years, and 76% at 15 and 20 years. We could not identify a statistically significant risk factor for reoperation. CONCLUSIONS: In patients with AVSD of various morphologies closure of the left AV valve cleft significantly improves outcome without affecting the need for reoperation. Risk factors for early and late death (multivariate analysis) were a pulmonary/aortic pressure ratio >0.7 and the occurrence of any complication after surgery. The concept of an early surgical AVSD correction before an increase in pulmonary vascular resistance and AV valve deformations occur would represent a better surgical option than a late correction as done in our series. Early correction allows for reduction of early mortality, superior long-term survival rates and a high freedom from subsequent valve degeneration.

Suppression of p53 function in normal human mammary epithelial cells increases sensitivity to extracellular matrix-induced apoptosis.

Little is known about the fate of normal human mammary epithelial cells (HMECs) that lose p53 function in the context of extracellular matrix (ECM)-derived growth and polarity signals. Retrovirally mediated expression of human papillomavirus type 16 (HPV-16) E6 and antisense oligodeoxynucleotides (ODNs) were used to suppress p53 function in HMECs as a model of early breast cancer. p53+ HMEC vector controls grew exponentially in reconstituted ECM (rECM) until day 6 and then underwent growth arrest on day 7. Ultrastructural examination of day 7 vector controls revealed acinus-like structures characteristic of normal mammary epithelium. In contrast, early passage p53- HMEC cells proliferated in rECM until day 6 but then underwent apoptosis on day 7. p53- HMEC-E6 passaged in non-rECM culture rapidly (8-10 passages), lost sensitivity to both rECM-induced growth arrest and polarity, and also developed resistance to rECM-induced apoptosis. Resistance was associated with altered expression of alpha3-integrin. Treatment of early passage p53- HMEC-E6 cells with either alpha3- or beta1-integrin function-blocking antibodies inhibited rECM-mediated growth arrest and induction of apoptosis. Our results indicate that suppression of p53 expression in HMECs by HPV-16 E6 and ODNs may sensitize cells to rECM-induced apoptosis and suggest a role for the alpha3/beta1-heterodimer in mediating apoptosis in HMECs grown in contact with rECM.

Anomalous 17O compositions in massive sulphate deposits on the Earth

The variation of delta 18O that results from nearly all physical, biological and chemical processes on the Earth is approximately twice as large as the variation of delta 17O. This so-called 'mass-dependent' fractionation is well documented in terrestrial minerals. Evidence for 'mass-independent' fractionation (delta 17O = delta 17O-0.52 delta 18O), where deviation from this tight relationship occurs, has so far been found only in meteoritic material and a few terrestrial atmospheric substances. In the rock record it is thought that oxygen isotopes have followed a mass-dependent relationship for at least the past 3.7 billion years, and no exception to this has been encountered for terrestrial solids. Here, however, we report oxygen-isotope values of two massive sulphate mineral deposits, which formed in surface environments on the Earth but show large isotopic anomalies (delta 17O up to 4.6%). These massive sulphate deposits are gypcretes from the central Namib Desert and the sulphate-bearing Miocene volcanic ash-beds in North America. The source of this isotope anomaly might be related to sulphur oxidation reactions in the atmosphere and therefore enable tracing of such oxidation. These findings also support the possibility of a chemical origin of variable isotope anomalies on other planets, such as Mars.

Effects of Functionalized Latex Particles and Anionic Surfactants on the Flow Behavior of Aqueous Gelatin Dispersions

The flow behavior of aqueous gelatin dispersions containing latex particles with different surface characteristics is studied as a function of the concentration of anionic surfactants. The work describes the nature and strength of interactions occurring in the system. The study of the effects of individual components may help to gain information on the flow behavior of commercial photographic color coupler dispersions. Due to interactions with the gelatin, the flow behavior of a dispersion of latex particles in 4.6% (w/w) aqueous gelatin solution depends strongly on charge and surface characteristics of the particles. For hard particles with nonionic hydrophilic shells, the flow behavior can be described by the theory of hard spheres. If anionic surfactants such as sodium i -dodecylbenzenesulfonate (DBS) or sodium di-sec -butylnaphthalenesulfonate (BXG) are added, the rheological behavior is mainly determined by the interactions between the gelatin and the surfactants in the continuous phase. If soft particles with ionic shells are dispersed in the aqueous gelatin, the viscosity is more strongly increased than predicted by the hard sphere model. Upon further addition of a surfactant, the primarily pseudoplastic flow behavior becomes more and more Newtonian, presumably due to depletion of originally surface-adsorbed gelatin molecules. The stabilization of the latex is changed from steric to electrostatic. If large amounts of surfactant are added, depletion flocculation is most likely to occur. A model of the gelatin-latex-surfactant interactions is presented which takes into account the surface characteristics of the particles.

Effect of crural myotomy on the incidence and mechanism of gastroesophageal reflux in cats.

BACKGROUND: Esophagogastric junction (EGJ) pressure is the major barrier to gastroesophageal reflux. Recent studies suggest that contraction of the crural diaphragm increases esophagogastric junction pressure. Whether this increase in EGJ pressure is important in the prevention of gastroesophageal reflux is not known. Our aim in this study was to determine the effects of crural myotomy on the occurrence of gastroesophageal reflux. METHODS: The spontaneous and stress gastroesophageal reflux before and after a surgical crural myotomy in four cats was studied. Spontaneous gastroesophageal reflux was recorded in the awake cats through a pH probe, placed via an esophagostomy, for periods of 12-24 hours. Stress reflux was studied during periods of airway obstruction and abdominal compression in anesthetized animals using the technique of simultaneous esophageal manometry and pH monitoring. RESULTS: There was a significant increase in the frequency of spontaneous acid reflux after crural myotomy. In anesthetized animals, there was an increase in the EGJ pressure during airway obstruction, which was abolished by a crural myotomy. Abdominal compression caused a reflex contraction at the EGJ that was not affected by crural myotomy. The crural myotomy resulted in a significant increase in the frequency of acid reflux during airway obstruction but not during abdominal compression. CONCLUSIONS: It is concluded that the crural diaphragm is important in the prevention of gastroesophageal reflux and its dysfunction leads to an increased incidence of gastroesophageal reflux.

Analysis of cell-associated recombinant hepatitis B surface antigen by flow cytometry.

Murine L cell lines secreting recombinant hepatitis B surface antigen (rHBsAg) of either the Adw or Ayw subtype were used as a model system to develop procedures for analysis of cell-associated HBV antigens by flow cytometry. Only weak membrane immunofluorescence was observed when viable Ad or Ay cells were reacted with monoclonal antibodies (MAbs) to either subtype specific or the common group specific "a" determinant of rHBsAg. Following fixation and permeabilisation to allow access of MAbs to the intracellular compartment, specific reactivity of cells with both anti-"a" and subtype specific MAbs was readily demonstrated by flow cytometric analysis. Comparison of the fluorescence histograms produced by analysis of Ad and Ay producing cells with the anti-"a" MAb demonstrated an increased proportion of cells with high levels of intracellular rHBsAg in the Ay line. The results of these studies demonstrate that flow cytometric analysis with MAbs is a useful tool for characterizing the expression of viral antigens at the cellular level. The application of this technique to monitoring the production of native viral proteins following in vitro infection should provide valuable insights into the process of viral replication.

A reassessment of the influence of steroids on neutrophil phagocytosis.

The impact of corticosteroids on host defense processes has been studied frequently because of its obvious clinical significance in many surgical patients. A technique that quantifies intraleukocyte iodination was used to measure polymorphonuclear leukocyte phagocytosis in heat inactivated and nonheat inactivated sera in the presence of two different corticosteroids: hydrocortisone sodium phosphate (HSP) and methylprednisolone sodium succinate (MSS). HSP produced a significant reduction in phagocytosis in the cells of healthy subjects when both heat inactivated autologous and isologous serum samples were used. MSS showed no such effect. Conversely, MSS produced a significant reduction in phagocytosis in the cells of healthy subjects when nonheat inactivated autologous serum was used but not when isologous serum was used. These data generally tend to confirm previous studies suggesting that MSS is less deleterious to some host defense processes than HSP and may be the steroid of choice when infection threatens the recipient.

Nonspecific stimulation of host defenses against bacterial challenge in immunosuppressed mice.

Muramyl dipeptide (MDP) has been shown to be a safe and effective host defense stimulant in both normal and malnourished hosts exposed to a bacterial challenge. We investigated its effect in mice compromised by pretreatment with either cyclophosphamide or steroids. The bacterial challenge, designed to simulate a surgical wound infection, consisted of a Klebsiella pneumoniae-laden suture. The MDP treatment resulted in lower local and systemic bacterial spread and increased survival in mice immunosuppressed by cyclophosphamide than in untreated controls. No such effect was demonstrated in animals compromised by steroids. These results suggest that MDP exerts its effect primarily on the macrophage.