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Introduction: Despite growing awareness of post-coronavirus disease 2019 (COVID-19) cholangiopathy as one of the most serious long-term gastrointestinal consequences of COVID-19, the endoscopic features of this disease are still poorly characterized. This study aimed to more precisely define its endoscopic features and to outline the role of endoscopic retrograde cholangiopancreatography (ERCP) in the management of this entity., Methods: In this observational study, 46 patients with confirmed post-COVID-19 cholangiopathy were included., Results: Based on the endoscopic features observed in 141 ERCP procedures, post-COVID-19 cholangiopathy can be classified as a variant of secondary sclerosing cholangitis in critically ill patients. It appeared early in the course of intensive care treatment of patients with COVID-19 (cholestasis onset 4.5 days after intubation, median). This form of cholangiopathy was more destructive than stricturing in nature and caused irreversible damage to the bile ducts. A centripetal pattern of intrahepatic bile duct destruction, the phenomenon of vanishing bile ducts, the absence of extrahepatic involvement, and the presence of intraductal biliary casts (85% of patients) were typical cholangiographic features of post-COVID-19 cholangiopathy. This cholangiopathy was often complicated by small peribiliary liver abscesses with isolation of Enterococcus faecium and Candida spp. in bile culture. The prognosis was dismal, with a 1-year liver transplantation-free survival rate of 44%. In particular, patients with peribiliary liver abscesses or destruction of the central bile ducts tended to have a poor prognosis (n.s.). As shown by multivariate analysis, bilirubin levels (on intensive care unit day 25-36) negatively correlated with liver transplantation-free survival (hazard ratio 1.08, P < 0.001). Interventional endoscopy with cast removal had a positive effect on cholestasis parameters (gamma-glutamyl transpeptidase, alkaline phosphatase, and bilirubin); approximately 60% of all individual values decreased., Discussion: Gastrointestinal endoscopy makes an important contribution to the management of post-COVID-19 cholangiopathy. ERCP is not only of great diagnostic and prognostic value but also has therapeutic value and therefore remains indispensable., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The American College of Gastroenterology.)

Background: Increasing evidence suggests that secondary sclerosing cholangitis (SSC), which can lead to cirrhosis or liver failure, may be a hepatobiliary long-term complication of COVID-19. The aim of this study was to estimate the frequency and outcome of this COVID-19 sequela and to identify possible risk factors., Methods: This observational study, conducted at University Hospital Charité Berlin and Unfallkrankenhaus Berlin, Germany, involved hospitalized patients with COVID-19 pneumonia, including 1082 ventilated COVID-19 patients. We compared COVID-19 patients who developed SSC with a COVID-19 control group by univariate and multivariate analyses., Results: SSC occurrence after COVID-19 was observed exclusively in critically ill patients with invasive ventilation, albeit with extreme clustering among them. One in every 43 invasively ventilated COVID-19 patients developed this complication. Risk factors preceding the development of secondary sclerosing cholangitis in critically ill COVID-19 patients (SSC-CIP) were signs of systemic reduced blood oxygen supply (e.g., low PaO 2 /FiO 2 , ischemic organ infarctions), multi-organ failure (high SOFA score) at admission, high fibrinogen levels and intravenous ketamine use. Multivariate analysis confirmed fibrinogen and increased plasma lactate dehydrogenase as independent risk factors associated with cholangiopathy onset. The 1-year transplant-free survival rate of COVID-19-associated SSC-CIP was 40%., Conclusions: COVID-19 causes SSC-CIP in a substantial proportion of critically ill patients. SSC-CIP most likely develops due to severe tissue hypoxia and fibrinogen-associated circulatory disturbances. A significant increase of patients with SSC-CIP is to be expected in the post-COVID era., (© 2023. The Author(s).)

Objective: To investigate the prevalence of underdiagnosis and undertreatment of traditional cardiovascular risk factors in RA patients., Methods: RA patients ⩽70 years of age without cardiovascular disease (CVD) or diabetes mellitus were included. Systolic blood pressure and a fasting lipid profile were measured. The 10-year CVD risk was estimated using the Dutch Cardiovascular Risk Management (CVRM) guideline and EULAR modifications of the Systemic Coronary Risk Evaluation tables., Results: A total of 327 patients were included (female gender: 68%). The mean age was 53 (11) years [mean (s.d.)]. The median disease duration was 7 years (inter quartile range: 2-14 years). According to the CVRM guideline, 52% of the patients had a CVD risk ⩾20% and according to the EULAR guidelines, 18% of the patients had a CVD risk ≥ 20%. Low-density lipoprotein cholesterol (LDL-C) >2.5 mmol/l was found in >80% of the patients with a CVD risk ⩾10% as estimated by both the CVRM and EULAR guidelines, and 32-42% of the patients with a CVD risk ⩾10% had a systolic blood pressure >140 mmHg, depending on the risk model used. Statins were used in 6% and antihypertensives in 23-25%, and 50-86% of these patients did not reach the recommended treatment targets., Conclusion: Regardless of the adapted risk assessment model used, untreated hypertension and hypercholesterolaemia were frequently found in RA patients with increased CVD risk. Treatment of these cardiovascular risk factors deserves more attention in RA., Trial Registration: The Dutch Trial Register, www.trialregister.nl, NTR3873., (© The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Objectives: Rheumatoid arthritis (RA) has been identified as an independent cardiovascular risk factor. The importance of risk factors such as hypertension and hyperlipidemia in the generation of atherosclerosis in RA patients is unclear. This study analyzed clinical parameters associated with carotid intima media thickness (cIMT) in patients with RA., Methods: Subjects with RA and healthy controls without RA, both without known cardiovascular disease, were included. Participants underwent a standard physical examination and laboratory measurements including a lipid profile. cIMT was measured semi-automatically by ultrasound., Results: In total 243 RA patients and 117 controls were included. The median RA disease duration was 7 years (IQR 2-14 years). The median DAS28 was 2.4 (IQR 1.6-3.2) and 114 (50.4%) of the RA patients were in remission. The presence of RA and cIMT were not associated (univariate analysis). Multivariable regression analysis showed that cIMT in RA patients was associated with age (B = 0.006, P<0.001) and systolic blood pressure (B = 0.003, P = 0.003). In controls, cIMT was associated with age (B = 0.006, P<0.001) and smoking (B = 0.097, P = 0.001)., Conclusion: cIMT values were similar between RA patients and controls. Hypertension was strongly associated with cIMT in RA patients. After adjustment, no association between cIMT and specific RA disease characteristics was found in this well treated RA cohort.

Background & Aims: Using high-density human recombinant protein microarrays, we identified two potential biomarkers, kelch-like 12 (KLHL12) and hexokinase-1 (HK1), in primary biliary cirrhosis (PBC). The objective of this study was to determine the diagnostic value of anti-KLHL12/HK1 autoantibodies in PBC. Initial discovery used sera from 22 patients with PBC and 62 non-PBC controls. KLHL12 and HK1 proteins were then analysed for immunoglobulin reactivity by immunoblot and enzyme-linked immunosorbent assay (ELISA) in two independent cohorts of PBC and disease/healthy control patients., Methods: Serum samples from 100 patients with PBC and 165 non-PBC disease controls were analysed by immunoblot and samples from 366 patients with PBC, 174 disease controls, and 80 healthy donors were tested by ELISA., Results: Anti-KLHL12 and anti-HK1 antibodies were each detected more frequently in PBC compared with non-PBC disease controls (P < 0.001). Not only are both markers highly specific for PBC (≥95%) but they also yielded higher sensitivity than anti-gp210 and anti-sp100 antibodies. Combining anti-HK1 and anti-KLHL12 with available markers (MIT3, gp210 and sp100), increased the diagnostic sensitivity for PBC. Most importantly, anti-KLHL12 and anti-HK1 antibodies were present in 10-35% of anti-mitochondrial antibody (AMA)-negative PBC patients and adding these two biomarkers to conventional PBC assays dramatically improved the serological sensitivity in AMA-negative PBC from 55% to 75% in immunoblot and 48.3% to 68.5% in ELISA., Conclusions: The addition of tests for highly specific anti-KLHL12 and anti-HK1 antibodies to AMA and ANA serological assays significantly improves efficacy in the clinical detection and diagnosis of PBC, especially for AMA-negative subjects., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

This study investigated the production of triacylglycerols in cells of the wild type of Escherichia coli and of a strain with a deleted diacylglycerol kinase gene (dgkA). By overexpression of atfA from Acinetobacter baylyi ADP1 and fadD from E. coli in the dgkA deletion mutant, cellular contents of up to 4.9% (w/w) triacylglycerols could be achieved in batch cultivation. Furthermore, heterologous expression of atfA relieves the negative effects of dgkA deletion on growth. Process optimization and fed-batch fermentation resulted in the production of 530 mg l (-1) triacylglycerols and a maximal content of 8.5% (w/w) triacylglycerols of the cell dry mass. This clearly exceeded all previous results concerning triacylglycerol production in E. coli. Furthermore, the production of extracellular free fatty acids and fatty acid ethyl esters was investigated. Like triacylglycerols, both products are potential biofuels, and we show their continuous production in a repeated batch process, with recovery of the production cells.

The idea of renewable and regenerative resources has inspired research for more than a hundred years. Ideally, the only spent energy will replenish itself, like plant material, sunlight, thermal energy or wind. Biodiesel or ethanol are examples, since their production relies mainly on plant material. However, it has become apparent that crop derived biofuels will not be sufficient to satisfy future energy demands. Thus, especially in the last decade a lot of research has focused on the production of next generation biofuels. A major subject of these investigations has been the microbial fatty acid biosynthesis with the aim to produce fatty acids or derivatives for substitution of diesel. As an industrially important organism and with the best studied microbial fatty acid biosynthesis, Escherichia coli has been chosen as producer in many of these studies and several reviews have been published in the fields of E. coli fatty acid biosynthesis or biofuels. However, most reviews discuss only one of these topics in detail, despite the fact, that a profound understanding of the involved enzymes and their regulation is necessary for efficient genetic engineering of the entire pathway. The first part of this review aims at summarizing the knowledge about fatty acid biosynthesis of E. coli and its regulation, and it provides the connection towards the production of fatty acids and related biofuels. The second part gives an overview about the achievements by genetic engineering of the fatty acid biosynthesis towards the production of next generation biofuels. Finally, the actual importance and potential of fatty acid-based biofuels will be discussed.

The refinement of biodiesel or renewable diesel from bacterial lipids has a great potential to make a contribution for energy production in the future. This study provides new data concerning suitable nutrient concentrations for cultivation of the Gram-positive Rhodococcus opacus PD630, which is able to accumulate large amounts of lipids during nitrogen limitation. Enhanced concentrations of magnesium have been shown to increase the final optical density and the lipid content of the cells. Elevated phosphate concentrations slowed down the onset of the accumulation phase, without a clear effect on the final optical density and the cell's lipid content. A robust growth of R. opacus was possible in the presence of ammonium concentrations of up to 1.4 g l(-1) and sucrose concentrations of up to 240 g l(-1), with an optimum regarding growth and lipid storage observed in the range of 0.2 to 0.4 g l(-1) ammonium and 20 to 40 g l(-1) sucrose, respectively. Moreover, R. opacus showed tolerance to high salt concentrations.

Enzymatic catalysis of oxygenation reactions in the absence of metal or organic cofactors is a considerable biochemical challenge. The CO-forming 1-H-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase (HOD) from Arthrobacter nitroguajacolicus Rü61a and 1-H-3-hydroxy-4-oxoquinoline 2,4-dioxygenase (QDO) from Pseudomonas putida 33/1 are homologous cofactor-independent dioxygenases involved in the breakdown of N-heteroaromatic compounds. To date, they are the only dioxygenases suggested to belong to the alpha/beta-hydrolase fold superfamily. Members of this family typically catalyze hydrolytic processes rather than oxygenation reactions. We present here the crystal structures of both HOD and QDO in their native state as well as the structure of HOD in complex with its natural 1-H-3-hydroxy-4-oxoquinaldine substrate, its N-acetylanthranilate reaction product, and chloride as dioxygen mimic. HOD and QDO are structurally very similar. They possess a classical alpha/beta-hydrolase fold core domain additionally equipped with a cap domain. Organic substrates bind in a preorganized active site with an orientation ideally suited for selective deprotonation of their hydroxyl group by a His/Asp charge-relay system affording the generation of electron-donating species. The "oxyanion hole" of the alpha/beta-hydrolase fold, typically employed to stabilize the tetrahedral intermediate in ester hydrolysis reactions, is utilized here to host and control oxygen chemistry, which is proposed to involve a peroxide anion intermediate. Product release by proton back transfer from the catalytic histidine is driven by minimization of intramolecular charge repulsion. Structural and kinetic data suggest a nonnucleophilic general-base mechanism. Our analysis provides a framework to explain cofactor-independent dioxygenation within a protein architecture generally employed to catalyze hydrolytic reactions.

A microfluidic high-resolution NMR flow probe based on a novel stripline detector chip is demonstrated. This tool is invaluable for the in situ monitoring of reactions performed in microreactors. As an example, the acetylation of benzyl alcohol with acetyl chloride was monitored. Because of the uncompromised (sub-Hz) resolution, this probe holds great promise for metabolomics studies, as shown by an analysis of 600 nL of human cerebrospinal fluid.

Study Objective: To determine--through reconstruction of a clinical situation in which a syringe filled with insulin was removed from the syringe pump, placed above the patient, then emptied into the patient--the different physical forces at work, and to examine the height of the syringe (and thus the hydrostatic force) necessary to move the plunger., Design: Prospective study., Setting: Research laboratory of a university., Measurements: The clinical situation was simulated using eight 50-mL and eight 20-mL syringes. A pressure transducer, placed between the syringe and the extension tubing, measured the pressure difference over the extension tubing. The Poiseuille equation of the viscous resistance was used to calculate flow., Main Results: The mean height needed for initiation of flow in the 50-mL syringes was 76 cm (range, 60-90 cm). In the 20-mL syringes, no flow could be generated up to heights of 200 cm. There was a large variability in the height and time required to generate flow in apparently identical syringes, probably due to differences in the static sticking of the plunger to the barrel., Conclusions: Studies testing the effect of siphoning using one syringe cannot be interpreted reliably. Smaller syringes are safer to avoid siphoning.

The Perinatal Grief Scale (PGS) has been used in many studies of loss in pregnancy, including miscarriage, stillbirth, induced abortion, neonatal death, and relinquishment for adoption. This article describes 22 studies from 4 countries that used the PGS with a total of 2485 participants. Studies that report Cronbach's alpha for their own samples give evidence of very high internal consistency reliability. Evidence for the validity of the PGS is also reviewed, such as convergent validity seen in its association with measures of mental health, social support, and marital satisfaction. The standard errors of the means for the total scale and for the subscales reveal fairly consistent scores, in spite of very different samples and types of loss; computation of means and standard deviations for the studies as a whole permits us to establish normal score ranges. Significantly higher scores were found in studies that recruited participants from support groups and self-selected populations rather than from medical sources, and from U.S. studies compared with those in Europe.

Background: This prospective longitudinal study investigated which selected person-oriented, social environment, demographic, and pregnancy-related risk factors could best predict women's grief intensity following pregnancy loss., Method: In a prospective longitudinal study, 2140 pregnant women within 12 weeks' gestation answered a first questionnaire in writing. Of this sample, 227 women experienced an involuntary pregnancy loss and were followed up for a period of 18 months, during which grief was reassessed four times, using the Perinatal Grief Scale. The prospectively measured risk factors were hierarchically ordered and linked to each woman's individual grief response over time., Results: The hypothesized risk factors, with the exception of a prior pregnancy loss, significantly related to grief intensity following the pregnancy loss and together explained 35% of the variance in grief scores among subjects. Gestational age, preloss neurotic personality, preloss psychiatric symptoms, and family composition showed the strongest relation to grief intensity following a pregnancy loss. Only psychiatric symptoms showed an interaction with time in that the women who evidenced more psychiatric symptoms before the pregnancy loss showed more intense grief shortly following the pregnancy loss. The other risk factors had a constant effect, irrespective of the time that had passed since the loss., Conclusion: A relatively long preloss pregnancy, a more neurotic personality, more preloss psychiatric symptoms, and the absence of living children appear to be important risk factors for stronger grief responses in women following a pregnancy loss.

Objective: This study investigated the hypothesis that following a pregnancy loss, women have more mental health complaints than women who give birth to a living baby., Method: Mental health was assessed for 2,140 women during their first trimester of pregnancy through use of the Dutch version of the SCL-90. A total of 227 women who had lost their babies and 213 women who gave birth to a living baby were followed over a period of 18 months, during which their mental health was reassessed four times., Results: When mental health complaints at the beginning of pregnancy and reproductive loss history were taken into account, data analysis revealed that up to 6 months after their pregnancy loss, women showed greater depression, anxiety, and somatization than women who gave birth to living babies. Over time the mental health of women who had experienced a loss was found to improve and at 1 year was comparable to that of women who gave birth to living babies and to that of women in general., Conclusions: The majority of women are able to recover from pregnancy loss without psychiatric treatment in about 1 year. A pregnancy loss is nevertheless a stressful life event that can give rise to a marked deterioration in a woman's mental health, particularly in the first 6 months following loss.

Climate control computers in greenhouses are used to control heating and ventilation, supply water and dilute and dispense nutrients. They integrate models into optimally controlled systems. This paper describes how information technology, as in use in other sectors of industry, is applied to greenhouse control. The introduction of modern software and hardware concepts in horticulture adds power and extra oppurtunities to climate contol in greenhouses.

Objective: To study the contribution of smoking and alcohol consumption to semen quality., Design: Retrospective analysis., Setting: University-based fertility clinic., Patients and Methods: Smoking and alcohol consumption were investigated in a control group (68) and in a group of 47 subjects with defined poor semen quality (PSQ). The control group was composed of subjects whose semen showed a greater than 60% morphological normality, a greater than 60% motility with a linear progression, and a density of greater than 20 million spermatozoa/mL. The group with PSQ was composed of subjects whose semen showed a less than 30% morphological normality, less than 60% motility, characterized by slow, weak motility, and a density of less than 20 million spermatozoa/mL. Medical dossiers were studied regarding the life style of the subjects., Results: The distribution of heavy smokers and light smokers did not differ statistically between the groups. There appeared to be a higher, but statistically insignificant, proportion of heavy smokers in the PSQ group (50%) compared to the control group (32.3%; P < .1); nor were significant differences found between cases and controls with respect to alcohol consumption pattern. In the PSQ group, a comparison of the semen characteristics of the daily drinkers with those of all the other subfertile patients showed no statistical difference concerning semen volume (4.1 +/- 1.9 vs. 3.3 +/- 1.3 mL; P > .1), sperm density (10.6 +/- 7.8 vs. 8.9 +/- 5.8 million spermatozoa/mL; P > or = .1), and percentage of motile spermatozoa (27.0 +/- 15.1 vs. 25.5 +/- 16.1%; P > .1). However, a lower percentage of normal sperm morphology was observed in the daily-drinker group (17.6 +/- 7.2% vs. 23.0 +/- 6.5% for the other subfertile patients; P < .05)., Conclusion: Factors such as smoking and alcohol consumption do not seem to play a pivotal role in the etiology of poor semen quality, but a pattern of excessive alcohol consumption may decrease further an already low percentage of sperm with normal morphology.

Objective: To test the effects of steroid-containing media such as follicular fluid (FF) and serum and of steroid-free but human protein-rich medium on hyperactivation (HA) of human spermatozoa with and without a preincubation period., Design: Analysis of HA using a computer-aided sperm analysis system., Setting: Academic hospital and andrologic laboratory., Patients: Twenty-six sperm samples were obtained from 26 different IVF patients., Interventions: None., Results: After a preincubation period of 3 hours, FF and serum enhanced the HA after 1 hour. A human plasma protein-rich solution did not. Without preincubation, no stimulation of HA was observed., Conclusion: Steroids may be involved in HA, and a preincubation period may be required for an appropriate FF-induced HA.

8 patients (7 women and 1 man, age between 35 and 66 years, mean 46.3) suffering from a stenosis or occlusion of the pelvic or superficial femoral vein after surgical or percutaneous intervention were successfully treated with endovascular stents of the wallstent type. Clinical and Doppler sonographic as well as phlebographic controls showed patency of all stented lesions at followup times between 3 and 82 months (average 27 months). The use of percutaneous transluminal angioplasty (PTA) in the venous system in combination with implantation of self-expanding vascular endoprostheses offer a new therapeutic modality to treat veins with stenosis or occlusion of benign etiology without surgical intervention.

In this paper we discuss the results of a study, conducted in the Netherlands, involving 143 women who experienced a miscarriage or stillbirth (response of 69%). The main questions were: how women with a fetal loss before the 20th week (miscarriage) versus women with a loss later in pregnancy (stillbirth) coped with the death of their baby; how the lapse of time since the loss related to grief intensity; and how satisfied women were with the professional care and support. The relationship between some other variables and grief intensity was also examined. It was found that grief intensity was greater and there was more satisfaction with professional care when gestational age was longer. With regard to the care, we concluded that some aspects needed improvement, especially the professional support for women who miscarry and the coordination of care for all women after discharge from hospital.

To study the effects of sperm density on the results of computer-assisted semen analysis (CASA), 10 washed semen samples were diluted and measured with the CellTrak/S CASA system in a concentration range of 10-180 x 10(6) spermatozoa/ml. All sperm motility parameters were influenced to some extent by sperm density. The motility percentage was influenced significantly in 5 samples (P < 0.005), the straight line velocity in all samples (P < 0.0005 in 7 samples), the curvilinear velocity in 3 samples (P < 0.005), the linearity in 9 samples (P < 0.0005 in 6 samples) and the lateral head displacement in 9 samples (P < 0.005 in 6 samples). In general, the CellTrak/S data are influenced significantly if sperm density exceeds 50 x 10(6) spermatozoa/ml. The influence of sperm density on the motility parameters can be explained both by the accuracy of the CASA system and by actual changes in the motility of the spermatozoa. In the light of other published studies, it is concluded that sperm motility measurements with CASA systems should be assessed using 25-50 x 10(6) spermatozoa/ml, especially in studies concerning lateral head displacement and the linearity, as in sperm hyperactivation studies.

The purpose of this study was to investigate the influence of antisperm antibodies in the male, the female, or both partners on the outcome of in vitro fertilization treatment. The results in terms of ongoing pregnancies in the male and female antibody-positive group were the same as in the antibody-negative group. In the double antibody-positive group two of the three patients became pregnant. When high levels of antisperm antibodies were present on the spermatozoa, the fertilization rate was significantly reduced. In the female positive group no clear relationship between the antibody titer and the fertilization percentage could be detected. Abnormal semen quality was responsible for a much lower fertilization rate than the presence of antibodies. The conclusion of this study is that in vitro fertilization provides an equal change of conception in couples with antisperm antibodies in comparison with couples with no antibodies if the other semen parameters are normal.

Objective: To study the reaction pattern of acrosome reaction in human semen and correlate it to the results of in vitro fertilization (IVF)., Design: The percentage of acrosome-reacted spermatozoa of 41 IVF semen samples was determined after 0, 2, 4, and 24 hours of incubation in human tubal fluid medium supplemented with 10% human pool serum., Setting: St. Radboud Hospital, Catholic University of Nijmegen, The Netherlands., Patients: Forty-one IVF couples., Interventions: None., Main Outcome Measure: Acrosome reaction was determined using fluorescein isothiocyanate conjugated concanavalin A lectin. To avoid false-positive signals from dead spermatozoa, the sperm viability was determined., Results: Three kinetic patterns of acrosome reaction could be distinguished: (1) normal reacting pattern (percentage of acrosome-reacted spermatozoa less than 10% at 2 hours and greater than 5% at 4 hours; 75% fertilization in IVF); (2) a quickly reacting pattern (percentage of acrosome-reacted spermatozoa greater than 10% at 2 hours; 22% fertilization in IVF); and (3) a nonreacting pattern (percentage of acrosome-reacted spermatozoa less than 5% at all time intervals studied; 15% fertilization in IVF)., Conclusions: The timing of acrosome reaction and the percentage of acrosome-reacted spermatozoa are very important parameters in IVF.

Objective: To study human sperm motility in a coculture system for in vitro fertilization (IVF)., Design: We studied the viability and motility (percentage and curvilinear velocity) of human spermatozoa after incubation in: (1) medium 199 supplemented with fetal calf serum (M199/FCS) together with Vero cells; (2) Vero cell conditioned M199/FCS; (3) M199/FCS supplemented with Vero cell extract; and (4) some control media. In a second experiment, FCS was substituted by sera from different IVF patients., Setting: Semen samples were obtained from the fertility laboratory of the St. Radbound Hospital, Nijmegen, The Netherlands., Patients: Twelve men of couples with fertility problems., Interventions: None., Main Outcome Measure: The motility parameters were determined with a computerized motility-analyzing system, after 24 hours' incubation at 37 degrees C and 5% CO2. Viability was determined after eosin Y staining., Results: Sperm viability was the same in all media. In the coincubation system, the Vero cell-conditioned medium, and the experiment with human sera, the sperm motility parameters were higher (P less than 0.005) than in the control media. Vero cell extract did not have this positive effect., Conclusions: Coincubation has a positive effect on sperm motility and may be beneficial to IVF, intrauterine insemination, and artificial insemination.

Ion-pair partition chromatography is applied to the separation of the biogenic catecholamines and their alpha-methyl homologues. A useful selectivity has been obtained using an adduct-forming organic stationary phase (tributylphosphate). The retention of the compounds can be regulated easily by means of the concentration of the counter-ion (the perchlorate ion) in the mobile phase. The selectivity for separation of amines from amino acids can be influenced by changing the pH of the aqueous phase. The phase system shows a good long-term stability and reproducibility with respect to the capacity ratios and the efficiency.