Adjusting the RAPID score with 2 additional variables significantly increases its predictive value in patients with empyema.

Pleural empyema is a serious condition leading to a significant burden on health care systems due to protracted hospitalisations. Treatment ranges from non-surgical interventions such as antibiotic therapy and chest tube placement to thoracoscopic or open surgery. Various risk factors which impact outcomes have been investigated. The RAPID (renal, age, purulence, infection source, and dietary factors) score is a clinical risk score which identifies patients at risk of death and may be used to formulate individual treatment strategies accordingly. All patients undergoing surgical interventions for empyema at a major tertiary medical centre in Germany from 2017 to 2020 were analysed. The aim was to identify perioperative risk factors which significantly impact treatment outcomes but are currently not included in the RAPID score. 245 patients with pleural empyema surgically treated at the Department of General, Visceral and Thoracic Surgery at the University Medical Centre, Hamburg, Germany (admitted from January 2017 to April 2020) were retrospectively analysed. All patients which received either minimally invasive or open thoracic surgery were included. Epidemiological as well as perioperative data was analysed to identify risk factors which impact long-term overall outcomes. 90-day mortality rate was the primary endpoint. The mean age was 59.4 years with a bimodal distribution. There was a male predominance across the cohort (71.4% compared to 28.6%), with no significant differences across ages below or above 60 years. 53 (21.6%) patients died within the first 90 days. Diabetes type 1 and 2, renal replacement therapy, immunosuppression, postoperative bleeding, intraoperative transfusion as well as microbiologically confirmed bacterial invasion of the pleura all led to higher mortality rates. Higher RAPID scores accurately predicted higher 90-day mortality rates. Modifying the RAPID score by adding the comorbidities diabetes and renal replacement therapy significantly increased the predictive value of the score. We demonstrated various perioperative and patient related risk-factors not included in the RAPID score which negatively impact postoperative outcome in patients receiving surgical treatment for pleural empyema. These should be taken into consideration when deciding on the best course of treatment. If confirmed in a prospective study including non-surgical patients with a significantly larger cohort, it may be worth considering expanding the RAPID score to include these.

Basal cell carcinoma risk and solar UV exposure in occupationally relevant anatomic sites: do histological subtype, tumor localization and Fitzpatrick phototype play a role? A population-based case-control study.

BACKGROUND: A two-fold risk increase to develop basal cell carcinoma was seen in outdoor workers exposed to high solar UV radiation compared to controls. However, there is an ongoing discussion whether histopathological subtype, tumor localization and Fitzpatrick phototype may influence the risk estimates. OBJECTIVES: To evaluate the influence of histological subtype, tumor localization and Fitzpatrick phototype on the risk to develop basal cell carcinoma in highly UV-exposed cases and controls compared to those with moderate or low solar UV exposure. METHODS: Six hundred forty-three participants suffering from incident basal cell carcinoma in commonly sun-exposed anatomic sites (capillitium, face, lip, neck, dorsum of the hands, forearms outside, décolleté) of a population-based, case-control, multicenter study performed from 2013 to 2015 in Germany were matched to controls without skin cancer. Multivariate logistic regression analysis was conducted stratified for histological subtype, phototype 1/2 and 3/4. Dose-response curves adjusted for age, age2, sex, phototype and non-occupational UV exposure were calculated. RESULTS: Participants with high versus no (OR 2.08; 95% CI 1.24-3.50; p = 0.006) or versus moderate (OR 2.05; 95% CI 1.15-3.65; p = 0.015) occupational UV exposure showed a more than two-fold significantly increased risk to develop BCC in commonly UV-exposed body sites. Multivariate regression analysis did not show an influence of phototype or histological subtype on risk estimates. The restriction of the analysis to BCC cases in commonly sun-exposed body sites did not influence the risk estimates. The occupational UV dosage leading to a 2-fold increased basal cell carcinoma risk was 6126 standard erythema doses. CONCLUSION: The risk to develop basal cell carcinoma in highly occupationally UV-exposed skin was doubled consistently, independent of histological subtype, tumor localization and Fitzpatrick phototype.

What predicts the outcome in patients with intestinal ischemia? A single center experience.

BACKGROUND: Acute mesenteric ischemia (AMI) is associated with a mortality of 60-80%. Early diagnosis and rapid treatment have a decisive influence on therapy. The aim of this study was to evaluate the prognostic value of AMI markers on mortality, in order to better anticipate the clinical course and to initiate therapeutic steps at an early stage. STUDY DESIGN: An analysis from our prospective database of 302 consecutive patients with AMI who were treated surgically in the Department of General Surgery between February 2003 and October 2014 was performed. Uni- and multivariate analysis of risk factors for mortality have been performed in the total cohort and in two subgroups according to their stay in intensive care unit (ICU) at the time of AMI diagnosis. RESULTS: Of the 302 patients with AMI, 115 were in ICU at the time of diagnosis. Totally, 203 patients underwent computed tomography scan (CT-scan) of the abdomen for diagnosis and 68% of them showed specific signs of AMI. A total of 63 (21%) embolectomies were performed during the surgical procedure. The post-operative mortality rate was 68% (204 patients). Among survivors, 85 (87%) patients developed a short bowel syndrome in the post-operative course. Multivariate analysis showed a significant association between mortality and preoperative lactate>3mmol/L, C-reactive protein>100mg/L and ICU stay at the time of AMI diagnosis. CONCLUSION: Mortality of patients with AMI remains high. Elevated lactate, elevated C-reactive protein and ICU stay are factors associated with increased mortality. Their presence in a patient with suspicion of AMI should trigger a multidisciplinary management in emergency.

Determination of reference intervals and comparison of venous blood gas parameters using a standard and nonstandard collection method in 51 dogs.

INTRODUCTION: The aim of this study was to determine reference intervals (RI) for venous blood parameters determined with the RAPIDPoint 500 (RP500) blood gas analyzer using blood gas syringes (BGS) and to determine whether immediate analysis of venous blood collected into lithium heparin (LH) tubes can replace anaerobic blood sampling into BGS. The null hypothesis was that canine venous blood samples collected in BGS and in LH tubes are comparable. Jugular blood was collected from 51 healthy dogs into a BGS and a LH tube. The BGS was immediately analyzed followed by the LH tube. The RI were calculated from BGS results. The BGS and LH tubes results were compared using paired t-test or Wilcoxon matched-pairs signed-rank test and Bland-Altman analysis. To assess clinical relevance, the bias between BGS and LH tubes was compared with the allowable total error (TEa). Values derived from LH tubes showed no significant difference for standard bicarbonate (HCO3std), whole blood base excess (BE B), Na, K, Cl, glucose and hemoglobin (tHb). The pH, partial pressure of carbon dioxide and oxygen, actual bicarbonate, extracellular base excess, ionized Ca, anion gap and lactate were significantly (p.

INTRODUCTION: Le but de la présente étude était de déterminer l'intervalle de référence (RI) de l'analyseur de gaz du sang RAPIDPoint 500 (RP500) pour du sang veineux prélevé dans des seringues pour gaz du sang (BGS) ainsi que de voir si une analyse immédiate du sang collecté dans des tubes à l'héparine de lithium (LH) pouvait remplacer la collecte anaérobe dans des seringues BGS. L'hypothèse était que les échantillons sanguins dans les seringues BGS et dans les tubes LH sont comparables. On a prélevé du sang de la veine jugulaire sur BGS et LH chez 51 chiens en bonne santé, on l'a analysé immédiatement avec l'analyseur RP500 et on a calculé les intervalles de référence pour les résultats des prélèvements sur BGS. Les résultats des prélèvements sur BGS et sur LH ont été comparés au moyen de t-test appariés ou d'un test de Wilcoxon signé ainsi que par une analyse de Bland-Altman. Pour juger de la signification clinique, on a comparé le biais entre BGS et LH avec une erreur globale admissible (TEa). Il n'y avait pas de différence significative entre BGS et LH en ce qui concerne le bicarbonate standard, l'excès basique du sang total, le sodium, le potassium, le glucose et l'hémoglobine. Le pH, les pressions partielles de gaz carbonique et d'oxygène, le bicarbonate effectif, l'excès basique extracellulaire, le calcium ionisé, le trou anionique et le lactate étaient significativement (p.

Is ultraviolet exposure acquired at work the most important risk factor for cutaneous squamous cell carcinoma? Results of the population-based case-control study FB-181.

BACKGROUND: Squamous cell carcinoma (SCC) is one of the most frequent types of cancer constituting a significant public health burden. Prevention strategies focus on limiting ultraviolet (UV) exposure during leisure time. However, the relative impact of occupational and nonoccupational UV exposure for SCC occurrence is unclear. OBJECTIVES: To investigate the association between occupational and nonoccupational UV exposure for SCC in a multicentre population-based case-control study hypothesizing that high occupational UV exposure increases the risk of SCC. METHODS: Consecutive patients with incident SCC (n = 632) were recruited from a German national dermatology network. Population-based controls (n = 996) without history of skin cancer were recruited from corresponding residents' registration offices and propensity score matched to cases. Lifetime UV exposure, sociodemographic and clinical characteristics were assessed by trained physicians. Occupational and nonoccupational UV exposure doses were estimated by masked investigators using established reference values. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were assessed using conditional logistic regression adjusting for relevant confounders. RESULTS: Total solar UV exposure was significantly associated with increased SCC. The OR for high (> 90th percentile) vs. low (< 40th percentile) and high vs, moderate (40-59th percentile) occupational UV exposure was 1·95 (95% CI 1·19-3·18) and 2·44 (95% CI 1·47-4·06) for SCC. Adjusting for occupational UV exposure, nonoccupational UV exposure was not significantly related to SCC incidence. Dose-response relationships were observed for occupational but not for nonoccupational solar UV exposure. CONCLUSIONS: Solar occupational UV exposure is a major determinant of incident SCC. Our findings indicate that prevention strategies should be further expanded to the occupational setting.

Blood fibrinogen levels discriminate low- and high-risk intraductal papillary mucinous neoplasms (IPMNs).

BACKROUND: The risk assessment of intraductal papillary mucinous neoplasms (IPMN) to either guide patients to surgical resection or watchful waiting is still under debate. Additional markers to better separate low and high-risk lesions would improve patient selection. METHODS: Patients who underwent pancreatic resections for IPMNs between January 2008 and December 2012 with available blood samples were selected and retrospectively assessed. Data on cyst characteristics such as cyst size, duct relation and main-duct dilatation were collected and plasma fibrinogen levels were measured. RESULTS: A total of 73 patients fulfilled the inclusion criteria by pancreatic resection for pathologically confirmed IPMN and available blood sample. Histologically, IPMNs were classified as low-grade and borderline in 52 (71.2%, group 1) and as high-grade and invasive in 21 (28.8%, group 2) of all cases. Fibrinogen levels showed significant differences between the two groups (group 1: mean 3.62 g/L (SD ± 1.14); group 2: mean 4.49 g/L (SD ± 1.57); p = 0.027). A ROC-curve analysis calculated cut-off value of 4.71 g/L separated groups 1 and 2 (p = 0.008). Fibrinogen levels remained as the only significant factor in multivariable analysis, cyst size and duct relation were not significant. CONCLUSION: Blood fibrinogen differed between low and high risk IPMNs and therefore, the use of fibrinogen as an additional discriminator in the pre-operative risk assessment of IPMNs should be further evaluated.

A patient with a hyperechoic band-shaped structure in the right hepatic vein.

Cement (polymethylmethacrylat) is frequently and increasingly used in vertebral surgery. Complications can occur by spillage of this material; however the vast majority of the patients remain free of symptoms and do not require any specific therapy.Internists, gastroenterologists and radiologists regularly performing abdominal ultrasound and computed tomography should be aware of this complication.A case of spillage of cement in the right hepatic vein is presented.

Non-trauma Emergency Pancreatoduodenectomies: A Single-Center Retrospective Analysis.

OBJECTIVE: To retrospectively assess the frequency and indications for emergency pancreatoduodenctomies in a tertiary referral center. METHODS: Pancreatoduodenectomies between January 2005 and January 2014 were retrospectively assessed for emergency indications defined as surgery following unplanned hospital admission in less than 24 h. Data on indications and on the intraoperative as well as the post-operative course were collected. RESULTS: Out of 583 pancreatoduodenectomies during the interval, a total of 10 (1.7 %) were performed as an emergency surgery. Indications included uncontrollable bleeding, duodenal and proximal jejunal perforations, and endoscopic retrograde cholangiopancreatography-related complications. Three of the 10 (30.0 %) patients died during the hospital course. In one patient, an intraoperative mass transfusion was necessary. No intraoperative death occurred. All but one patient were American Society of Anesthesiologists class three or higher. In two cases, the pancreatic remnant was left without anastomosis for second-stage pancreatojejunostomy. Median operation time was 326.5 min (SD 100.3 min). Hospital stay of the surviving patients was prolonged (median 43.0 days; SD 24.0 days). CONCLUSION: Emergency pancreatoduodenectomies are non-frequent, have a diverse range of indications and serve as an ultima ratio to cope with severe injuries and complications around the pancreatic head area.

Diverse prognostic value of the GTn promoter polymorphism in squamous cell and adeno carcinoma of the oesophagus.

The basal transcription of heme oxygenase-1 (HO-1) regulation is dependent upon a GT repeat germ line polymorphism (GTn) in the promoter of the HO-1 gene. We determined the prognostic value of HO-1 promoter polymorphism on the natural postoperative course of complete resected oesophageal cancer. Genomic DNA from 297 patients was amplified by polymerase chain reaction and sequenced. The results were correlated with clinicopathological parameters, disseminated tumour cells in bone marrow (DTC) and clinical outcome. Depending on short allele with <25 and long allele with ≥25, GTn repeats three genotypes (SS, SL and LL) were defined. A diverse role of GTn was evident in squamous cell carcinoma (SCC) and adenocarcinoma (AC). In SCC, the SS genotype presented less advanced tumours with lower rate DTC in bone marrow and relapse compared with L-allele carriers. In contrast, AC patients with the SS genotype displayed a complete opposing tumour characteristic. The disease-free (DFS) and overall survival (OS) in SCC patients was markedly reduced in LL genotypes (p < 0.001). In AC contrarily the SS genotype patients displayed the worst DFS and OS (p < 0.001). GTn is a strong prognostic factor with diverse prognostic value for recurrence and survival in AC and SCC.

[New guidelines on chronic pancreatitis : interdisciplinary treatment strategies]. / Neue Leitlinie zur chronischen Pankreatitis : Interdisziplinäre Behandlungsstrategien.

Chronic pancreatitis is a common disorder associated with significant morbidity and mortality. Interdisciplinary consensus guidelines have recently updated the definitions and diagnostic criteria for chronic pancreatitis and provide a critical assessment of therapeutic procedures. Diagnostic imaging relies on endoscopic ultrasound (EUS) as the most sensitive technique, whereas computed tomography (CT) and magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) remain a frequent preoperative requirement. Endoscopic retrograde cholangiopancreatography (ERCP) is now used mostly as a therapeutic procedure except for the differential diagnosis of autoimmune pancreatitis. Complications of chronic pancreatitis, such as pseudocysts, duct stricture and intractable pain can be treated with endoscopic interventions as well as open surgery. In the treatment of pseudocysts endoscopic drainage procedures now prevail while pain treatment has greater long-term effectiveness following surgical procedures. Currently, endocopic as well as surgical treatment of chronic pancreatitis require an ever increasing degree of technical and medical expertise and are provided increasingly more often by interdisciplinary centres. Surgical treatment is superior to interventional therapy regarding the outcome of pain control and duodenum-preserving pancreatic head resection is presently the surgical procedure of choice.

Is Toupet fundoplication the procedure of choice for treating gastroesophageal reflux disease? Results of a prospective randomized experimental trial comparing three major antireflux operations in a porcine model.

BACKGROUND: Gastroesophageal reflux disease (GERD) is among the most common dysfunctions of the upper gastrointestinal tract. It interferes with quality of life and is a risk factor for the development of adenocarcinoma in the lower esophagus. Laparoscopic fundoplication is an effective treatment of GERD, but the physiologic mechanisms of the different available procedures had not been investigated to date. METHODS: In this study, 28 German Landrace pigs underwent baseline manometry and 24-h pH monitoring followed by myotomy to induce reflux esophagitis. After new-onset reflux was proved, the pigs were randomized to groups based on four treatments: total fundoplication, anterior hemifundoplication, posterior hemifundoplication, and control. On days 10 and 60 after the intervention, the effectiveness of the different fundoplication modifications was compared with that of the control subjects by 24-h pH monitoring manometry. Finally, the pigs were killed, after which the minimum volume and pressure required to breach the gastroesophageal junction were recorded. RESULTS: After myotomy, a significant increase in the reflux could be confirmed. The findings after fundoplication showed a significant decrease in the fraction of time that the pH fell below four and an increase in the vector volume compared with the measurement after myotomy. Total fundoplication and posterior hemifundoplication were highly effective, whereas measurements after anterior fundoplication still showed increased fraction times. Pharmacologic stimulation with pentagastrin showed an increase in the vector volume of the esophageal sphincter. CONCLUSIONS: Total fundoplication and posterior hemifundoplication are potent operations for the treatment of GERD. Anterior hemifundoplication reduces the reflux as well, but the effects are significantly less than with total and posterior fundoplication. Pharmacologic stimulation showed excellent results after posterior hemifundoplication, and a tendency to overcorrection was shown after total fundoplication.

[A new cholecystectomy with no visible scarring and low risk. A possible alternative to natural orifice transluminal endoscopic surgery]. / Suprasymphysäre laparoskopische Cholezystektomie ohne sichtbare Narben. Eine Alternative zu NOTES?

Laparoscopic cholecystectomy was established in the 1980s and is the gold standard for treating cholecystolithiasis and cholecystitis. Laparoscopy offers reduction of postoperative pain, smaller scars, and a lower complication rate, resulting in shorter hospitalisation and faster recovery. In recent years alternative approaches for cholecystectomy have been developed to meet requirements of aesthetic surgery (scarless surgery, natural orifice transluminal endoscopic surgery). Access to the abdominal cavity with these methods is transgastral, transcolonal via endoscopy, or transvaginal with potential fatal effects such as peritonitis. In this paper a new variation with minimal risks is presented. In contrast to conventional laparoscopy, no visible scars are left behind.

[Arterio-venous aneurysm of splenic vessels--a rare differential diagnosis for cardio-circulatory symptoms]. / Arteriovenöses Aneurysma der Milzgefässe--Eine seltene Differentialdiagnose bei kardio-zirkulatorischen Symptomen.

Patients with arterio-venous fistula of the splenic hilum seek medical assistance because of abdominal discomfort and symptoms of portal hypertension. We report on a 43 year old female who was diagnosed with an arterio-venous aneurysm after suffering from dyspnoea, tachycardia and extrasystolies for several years. After uncomplicated distal splenopancreatectomy the patient was discharged free of symptoms.

Inhibition constants, inhibitor concentrations and the prediction of inhibitory drug drug interactions: pitfalls, progress and promise.

Strategies and standards for predicting the likelihood of pharmacokinetically significant inhibitory drug-drug interactions for drug development purposes which rely primarily on projected in vivo concentrations of cytochrome P450 (CYP) or transporter inhibitors, [I], and in vitro estimates of their inhibitory constants, K(i), were specified in several commentaries based upon a conference held by the European Federation of Pharmaceutical Sciences (EUFEPS) several years ago. Since then the application of those strategies and standards has met with varying degrees of success. Many of the vexing issues that were identified in the EUFEPS Conference Report remain, while other issues are systematically being resolved. This article briefly reviews the underlying strategy in the prediction of the significance of inhibitory DDIs using [I]/K(i) ratios; some of the difficulties or pitfalls associated with the predictive application of [I]/K(i) ratios; and some of the recent refinements of the general strategy.

Randomized placebo-controlled trial of a flavonoid-rich plant extract-based cream in the treatment of rosacea.

BACKGROUND: Biological research suggests that vascular changes may play a major role in rosacea pathogenesis. Chrysanthellum indicum is a plant-based extract containing a unique combination of phenylpropenoic acids, flavonoids and saponosids, and has a well-documented effect on vascular wall permeability and increase of the mechanical resistance of capillaries. OBJECTIVE: To determine the efficacy and safety of a cream containing 1%C. indicum extract with vitamin P properties in the treatment of rosacea. METHODS: This study included 246 patients diagnosed clinically as having moderate rosacea. Patients were randomly allocated to C. indicum extract-based cream (n = 125) and placebo (n = 121) groups. Patients were advised to apply the products on their face twice a day for a 12-week period. The patients were examined at the end of each 4-week period. Severity of erythema (graded by reference to six photographs), surface of erythema and rosacea overall severity scores were recorded at each visit on days 0, 28, 56 and 84. Investigators carried out a final efficacy assessment at the end of week 12. Volunteers' final overall efficacy assessment was recorded in a self-administered questionnaire. Adverse events were identified through examination, interview and collection of comments in patients' questionnaires. RESULTS: Treatment with the C. indicum extract-based cream resulted in significant improvement (P < 0.05) in severity of erythema, overall rosacea severity compared to baseline and placebo, and investigator and patient overall efficacy assessment scores (P = 0.046 and P = 0.001, respectively) compared with placebo scores. Adverse reactions were mild, and did not differ between the C. indicum extract-based cream and the placebo groups. CONCLUSION: Chrysanthellum indicum extract-based cream is an effective and well-tolerated topical agent for the treatment of moderate rosacea. The mode of action of the active ingredient suggests that additional efficacy might be expected from combination with other topical treatments.

QTL mapping for a trade-off between leaf and bud production in a recombinant inbred population of Microseris douglasii and M. bigelovii (Asteraceae, Lactuceae): a potential preadaptation for the colonization of serpentine soils.

The different response to growth on serpentine soil is a major autecological difference between the annual asteracean species Microseris douglasii and M. bigelovii, with nearly non-overlapping distribution ranges in California. Early flowering and seed set is regarded as a crucial character contributing to escape drought and thus is strongly correlated with survival and reproductive success on serpentine as naturally toxic soil. M. bigelovii (strain C94) from non-serpentine soil produces more leaves at the expense of bud production in the first growing phase than M. douglasii (B14) from serpentine soil. A QTL mapping study for this trade-off and for other growth-related traits was performed after six generations of inbreeding (F7) from a single interspecific hybrid between B14 and C94 on plants that were grown on serpentine and alternatively on normal potting soil. The trade-off is mainly correlated with markers on one map region on linkage group 03a (lg03a) with major phenotypic effects (phenotypic variance explained [PVE] = 18.8 - 31.7 %). Plants with the M. douglasii allele in QTL-B1 (QTL-NL1) produce more buds but fewer leaves in the first 119 days on both soil types. Three modifier QTL could be mapped for bud and leaf production. In one modifier (QTL-B2 = QTL-NL4) the M. douglasii allele is again associated with more buds but fewer leaves. QTL mapped for bud set in the F6 co-localize with QTL-B1 (major QTL) and QTL-B3. Two additional QTL for leaf length and red coloration of leaves could be mapped to one map region on lg03a. Co-localization of the two QTL loci with major phenotypic effects on bud and leaf production strongly suggests that a major genetic locus controls the trade-off between the two adaptive traits. The importance of mutational changes in major genes for the adaptation to stressful environments is discussed.

Geographic distribution and recombination of genomic fragments on the short arm of chromosome 2 of Arabidopsis thaliana.

Range expansion from Pleistocene refugia and anthropogenic influences contribute to the present distribution pattern of Arabidopsis thaliana. We scored a genome-wide set of CAPSs and found two markers with an east-west geographic distribution across the Eurasian range of the species. Regions around the two SNPs were sequenced in 98 accessions, including newly collected plants from Middle Asia and Western Siberia. These regions correspond to a gene ( approximately 1500 bp) and a non-coding region ( approximately 500 bp) 300 kbp apart on chromosome 2. Nucleotide diversities, pi, of the two sequenced fragments were 0.0032 and 0.0130. The haplotypes of both sequences belonged to one of two groups: a rather uniform "Asian" and a more variable "European" haplotype group, on the basis of non-disjunct clusters of SNPs. Recombination between "Asian" and "European" haplotypes occurs where they meet. Especially in the "European" haplotype, many rare SNP variants representing independent mutations are scattered among the shared haplotype-specific SNPs. This agrees with previous suggestions of two large haplotype groups in A. thaliana and the post-glacial colonization of central Europe from the east and the west. A clear correlation between climatic factors and the haplotype distribution may reflect the dispersal history rather than local climate adaptation. The pattern of SNP variation within the contiguous sequences explains why only a minority of SNPs selected across the genome show evidence of this geographic pattern.

QTL mapping reveals a two-step model for the evolutionary reduction of inner microsporangia within the asteracean genus Microseris.

The reduction of inner (adaxial) pollen sacs (microsporangia, MS) as a diagnostic character for the three asteracean species, Microseris bigelovii, Microseris elegans and Microseris pygmaea, was analysed in an interspecific cross between Microseris douglasii and Microseris bigelovii with 4 MS and 2 MS, respectively, using the average number of MS per plant as a quantitative character. A previous QTL (Quantitative Trait Locus) analysis had revealed one major QTL (3B) and three modifier QTLs (3A, 4A, 7A) with epistatic effects only on the homozygous recessive 2 MS genotype of QTL 3B. Here we performed a bulked segregant analysis on four 2 MS and four 4 MS DNA-bulks with 407 EcoRI/ MseI AFLP-primer combinations each. In this way additional AFLP markers were mapped close to QTL 3B and QTL 3A. Three of them were converted to SCAR (Sequence Characterized Amplified region) markers. All markers were tested in natural populations of the disporangiate (2 MS) species M. bigelovii, M. elegans and M. pygmaea, and in different populations of tetrasporangiate (4 MS) M. douglasii. The marker distribution suggests that locus 3B mutated in a progenitor of the disporangiate species. QTL 3A has evolved in the 2 MS background of the major gene in the disporangiate species. Since M. pygmaea and M. bigelovii are the sister group to M. elegans, the 4 MS genotype for (markers of) QTL 3A in M. pygmaea populations is most likely due to a back mutation to the 4 MS state and could explain the slight instability of the 2 MS phenotype in this species.

Prediction of in vivo hepatic clearance from in vitro data using cryopreserved human hepatocytes.

1. Cryopreserved human hepatocytes were used to predict in vivo hepatic clearance (CL(hepatic)) from estimates of in vitro intrinsic clearance (CL' int). 2. (CL' int) was estimated for phenytoin, valproic acid, carbamazepine, theophylline, quinidine and procainamide after their addition to hepatocytes suspended either in human serum or in serum-free media. (CL' int)was estimated from in vitro concentration versus time data fitted to a monoexponential decay model. (CL' int) was estimated from concentrations measured at four time points and from just two-point measures, namely the initial concentration (C(0)) and the final concentration measurement (C(last)). 3. Predicted CL(hepatic) was within twofold of reported in vivo values of CL(hepatic) for all substrates. Moreover, predictions were not significantly different whether derived from hepatocytes suspended in serum or in serum-free medium. 4. Two-point estimates of (CL' int) were just as accurate in predicting CL(hepatic) as were multipoint estimates of (CL' int). 5. Although the data set was limited, the findings suggest that the measurement of the disappearance of xenobiotics from serum or serum-free media in which primary human hepatocytes have been suspended provides a physiologically relevant estimate of hepatic clearance that can be employed early in the drug development process to eliminate xenobiotics with unacceptable clearances.