Anxiety, depression, and body image among infertile women with and without polycystic ovary syndrome.

STUDY QUESTION: In women undergoing fertility treatment, do those with polycystic ovary syndrome (PCOS) have a higher prevalence of symptoms of anxiety and depression and lower body appreciation than women without PCOS? SUMMARY ANSWER: Having PCOS was not associated with symptoms of anxiety and depression but was associated with somewhat lower body appreciation. WHAT IS KNOWN ALREADY: PCOS has been associated with a higher chance to develop mental health problems, like anxiety, and body image concerns. The International Guidelines on PCOS recommend that all women with PCOS should routinely be screened for anxiety and depressive disorders. In most studies in this field, the comparison group included healthy women without fertility problems. STUDY DESIGN, SIZE, DURATION: We conducted a cross-sectional survey study between May 2021 and July 2023, using an online questionnaire. We informed women about this study at fertility clinics in the Netherlands through posters and leaflets and on the websites of the Dutch patient organizations Freya and Stichting PCOS. PARTICIPANTS/MATERIALS, SETTING, METHODS: This study included women with infertility, with and without PCOS, who were undergoing fertility treatment. Women completed two assessment tools: the Hospital Anxiety and Depression Scale (HADS) and the Body Appreciation Scale-2 (BAS-2). Primary outcomes were clinically relevant symptoms of anxiety (score ≥ 11) and depression (score ≥ 11), and BAS-2 scores. Secondary outcomes were mean anxiety and depression scores and anxiety and depression scores of 8 and higher. Dichotomous outcomes and continuous outcomes were analysed using logistic and linear regression analyses adjusted for age, BMI, and duration of infertility. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 1025 women currently undergoing infertility treatment participated, of whom 502 (49.0%) had PCOS and 523 (51.0%) had other infertility diagnoses. We found self-reported clinically relevant symptoms of anxiety in 33.1% of women with PCOS and in 31.0% of women with other infertility diagnoses (adjusted OR: 0.99, 95% CI 0.74-1.31). Clinically relevant symptoms of depression were reported in 15.5% of women with PCOS versus 14.5% of women with other infertility diagnoses (adjusted OR: 1.04, 95% CI 0.71-1.50). Women with PCOS reported slightly less body appreciation (adjusted mean difference: -1.34, 95% CI -2.32 to -0.36). LIMITATIONS, REASONS FOR CAUTION: Results are based on self-report and may have been affected by sampling bias. WIDER IMPLICATIONS OF THE FINDINGS: Although guidelines recommend screening women with PCOS, feelings of anxiety and depression can be present in any woman undergoing fertility treatments. We advise fertility clinics to be aware of women's mental health issues and to offer support accordingly, as a part of routine care. STUDY FUNDING/COMPETING INTEREST(S): This study did not receive specific funding. All authors report no conflict of interest related to the current research. TRIAL REGISTRATION NUMBER: This study was pre-registered at OSF: https://osf.io/qbeav.

The increasing burden of testicular seminomas and non-seminomas in adolescents and young adults (AYAs): incidence, treatment, disease-specific survival and mortality trends in the Netherlands between 1989 and 2019.

BACKGROUND: Testicular cancer incidence among adolescents and young adults (AYAs, aged 18-39 years at diagnosis) is increasing worldwide and most patients will survive the initial disease. Still, detailed epidemiological information about testicular cancer among AYAs is scarce. This study aimed to provide a detailed overview of testicular cancer trends in incidence, treatment, long-term relative survival and mortality by histological subtype among AYAs diagnosed in the Netherlands between 1989 and 2019. MATERIALS AND METHODS: Data of all malignant testicular cancers (ICD-code C62) were extracted from the Netherlands Cancer Registry. Mortality data were retrieved from Statistics Netherlands. European age-standardized incidence and mortality rates with average annual percentage change statistics and relative survival estimates up to 20 years of follow-up were calculated. RESULTS: A total of 12 528 testicular cancers were diagnosed between 1989 and 2019. Comparing 1989-1999 to 2010-2019, the incidence increased from 4.4 to 11.4 for seminomas and from 5.7 to 11.1 per 100 000 person-years for non-seminomas. Rising trends were most prominent for localized disease. Radiotherapy use in localized testicular seminomas declined from 78% in 1989-1993 to 5% in 2015-2019. Meanwhile, there was a slight increase in chemotherapy use. Most AYAs with localized seminomas and non-seminomas received active surveillance only (>80%). Overall, relative survival estimates remained well above 90% even at 20 years of follow-up for both seminomas and non-seminomas. Mortality rates declined from 0.5 to 0.4 per 100 000 person-years between 1989-1999 and 2010-2019. CONCLUSIONS: The incidence of seminoma and non-seminoma testicular cancers significantly increased in AYAs in the Netherlands between 1989 and 2019. There was a shift towards less-aggressive treatment regimens without negative survival effects. Relative survival estimates remained well above 90% at 20 years of follow-up in most cases. Testicular cancer mortality was already low, but has improved further over time, which makes survivorship care an important issue for these young adults.

Communication about Prognosis during Patient-Initiated Second Opinion Consultations in Advanced Cancer Care: An Observational Qualitative Analysis.

Prognostic communication is essential for patients with advanced cancer to enable informed medical decision-making and end-of-life planning. Discussing prognosis is challenging, and might be especially complex for oncologists conducting a second opinion (SO). Survival data are often lacking, and consulting oncologists need to consider previously conveyed information and patients' relationship with the referring oncologist. We qualitatively investigated how advanced cancer patients and consulting oncologists discuss prognosis during audio-recorded SO consultations (N = 60), including prognostic information received from the referring oncologist. Our results show that patients regularly expressed implicit cues to discuss prognosis or posed explicit questions tentatively. Consulting oncologists were mostly unresponsive to patients' cues and cautious to prognosticate. They also seemed cautious when patients brought up the referring oncologist. Consulting oncologists checked which prognostic information patients had received from the referring oncologist, before estimating prognosis. They agreed with the first opinion or rectified discrepancies carefully. Altogether, this study exposes missed opportunities for open prognostic discussions in SOs. Consulting oncologists could explicitly explore patients' information preferences and perceptions of prognosis. If desired, they can provide tailored, independent information to optimise patients' prognostic awareness and informed medical decision-making. They may additionally support patients in dealing with prognosis and the uncertainties associated with it.

Fertility-related knowledge and reproductive goals in childhood cancer survivors: short communication.

STUDY QUESTION: Do young adult survivors of childhood cancer know their fertility status, in the context of their parenthood goals and screening for gonadal functioning? SUMMARY ANSWER: While 80% of survivors (who were without children) wanted children in the future, most did not know their fertility status, and screening for gonadal functioning was underutilized. WHAT IS KNOWN ALREADY: Survivors of childhood cancer are at risk for infertility, but fertility counseling and assessment are underutilized. Separate studies indicated that survivors' fertility-related knowledge is poor and that they often wanted to have children. Yet, studies have not investigated the intersection of both issues, as well as potential distress if parenthood goals are not met. STUDY DESIGN, SIZE, DURATION: Young adult male and female survivors of childhood cancer (N = 149) completed cross-sectional surveys, and data for those without children (n = 105, 70.5%) are presented here. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants were 20-40 years old (M = 26.5), diagnosed 5-33 years prior to study participation, and completed questionnaires online. Knowledge of fertility status, parenthood goals, and potential distress if survivors were unable to have children were assessed. Medical records were reviewed for hormone levels as indicators of screening for gonadal functioning. MAIN RESULTS AND THE ROLE OF CHANCE: Most survivors (n = 81; 77.1%) did not know their fertility status, while over 80% (n = 89) wanted children (neither aspect varied by socio-demographic/cancer-specific factors). Two-thirds of survivors indicated they would be distressed if parenthood goals remained unfulfilled; especially female (versus male, t = 2.64; P = 0.01) or partnered (versus single, t = -3.45; P < 0.001) survivors. Forty survivors (38.1%) had documented assessments of gonadal functioning, of which 33 (82.5%) reported not knowing their fertility status. LIMITATIONS, REASONS FOR CAUTION: Relevant risk factors may have not been identified owing to limited sample size and missing treatment information. The underutilization of screening for gonadal functioning needs further exploration in other pediatric centers. WIDER IMPLICATIONS OF THE FINDINGS: Most adult childhood cancer survivors want to become parents, but do not know their fertility status, which could cause significant psychological distress. Healthcare providers should continuously address fertility among survivors, but more research is needed on how to implement routine fertility counseling and/or testing. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the Research Institute at Nationwide Children's Hospital (V.L.) and Dutch Cancer Society (RUG2009-4442, M.A.T.). All authors have no conflict of interest to declare.

Following the transfer of DNA: How does the presence of background DNA affect the transfer and detection of a target source of DNA?

DNA transfer is of increasing importance in crime scene situations, partly due to analytical techniques detecting profiles in ever declining amounts of DNA. Whereas the focus has previously been DNA transfer of target sources, the effects of background DNA on transfer and detection of DNA after multiple contact situations have been much less investigated. This study measured the transfer and detection rates of a specific DNA source in the presence of background DNA sources. The presence of background DNA influenced the transfer of DNA differently depending on the combination of biological material and surface type. The detection of a profile from the target DNA decreased after multiple contact situations, due to the reduced total and relative quantity of target DNA, and the increasing complexity of the mixture. The results of this study contribute to a greater understanding of the effects of background DNA sources on DNA transfer and detection.

[Pediatric emergence agitation]. / Postoperative Agitation im Kindesalter.

BACKGROUND: The origin of emergence agitation in children remains unclear; however, an association between surgical procedure, patient age and anesthetic regimen and the incidence of postoperative agitation has been described in the literature. AIM: The aim of this survey performed between February and April 2014 was to collect data from the daily clinical practice by experienced pediatric anesthesiologists regarding documentation, premedication, anesthesia regimen and postoperative treatment with respect to children with emergence agitation. MATERIAL AND METHODS: An online questionnaire with 33 items was developed and sent to all 525 members of the scientific committee of pediatric anesthesia (WAKKA) of the German Society of Anesthesiology and Intensive Care (DGAI). Members were asked to respond within a time period of 1 month but no reminders were sent out via email or telephone. RESULTS: A total of 156 members participated in the survey and of these 143 questionnaires were fully completed and included in the final evaluation (27 %). Of the participants 77 % had more than 6 years professional experience in the field of pediatric anesthesia and for 87 % emergence agitation remains a relevant clinical problem. The estimated incidence of emergence agitation was given as 1-10 % and as high as 11-20 % by 56% and 20 % of the participants, respectively. The incidence of postoperative agitation is documented by only 11 % of the participants with a validated score, such as the pediatric anesthesia emergence delirium (PEAD) scale and 89 % of the participants use midazolam for premedication. As a preemptive intervention total intravenous anesthesia is performed by 56 % whereas clonidine is used as first line prevention by 30 %. Postoperative pharmacological treatment is performed by a bolus administration of propofol (56 %) and clonidine (26 %). Postoperative parental presence was considered beneficial by 82 %. CONCLUSION: Emergence agitation is still seen as a relevant clinical problem by experienced pediatric anesthesiologists. Propofol is first choice when it comes to pharmacological prevention and treatment of emergence agitation. Postoperative parental presence was considered beneficial by the majority of anesthesiologists.

[Influencing of the PSA concentration in serum by physical exercise (especially bicycle riding)]. / Beeinflussung der PSA-Konzentration im Serum durch körperliche Belastung (insbesondere Fahrradfahren).

BACKGROUND: Sports and in particular cycling are assumed to influence PSA in serum. Controversial scientific results were the motivation to examine the influence of a standardized test on a cycling ergometer and a treadmill on PSA concentrations in elderly men with elevated PSA levels and a benign prostate hyperplasia. MATERIAL AND METHODS: A total of 21 male volunteers (aged 61 ± 5 years, tPSA 7.7 ± 3.0 ng/ml and benign prostate hyperplasia with a prostate volume of 54 ± 18 ml) performed a 1 h cycling test on a cycling ergometer. A subgroup of 15 volunteers also performed a 1 h test on a treadmill. Blood samples were drawn before and several times after the cycling stress test up to 7 days afterwards (up to 120 min after the test on the treadmill) to determine total PSA (tPSA), complexed PSA (cPSA) and free PSA (fPSA). RESULTS: The average increase in tPSA of 1.9 ± 1.7 ng/ml (25%) after the cycling exercise test was significant. After the treadmill exercise the PSA increase was not as high, but with 1.0 ± 1.0 ng/ml (12%) was also significant. On average the levels of PSA returned to the basic level 48 h after the cycling test, but in individual cases it took longer. fPSA showed the most noticeable increase after cycling with 92% on average. There was no correlation between increase in PSA and prostate volume. CONCLUSIONS: Men should abstain from physical exercise, especially from cycling for several days and at least for 24 h before PSA measurements are carried out. This applies to patients with elevated PSA levels (>4 ng/ml) when a PSA follow-up is being carried out.

Influence of phosphate on the response of periphyton to atrazine exposure.

After indications from the literature that nutrient concentrations may modify the toxicity of herbicides to natural periphyton communities, this study aims to provide experimental proof for atrazine. In this microcosm experiment, phosphate (P) addition did not ameliorate atrazine toxicity to periphyton. Three weeks of P addition did not increase atrazine tolerance (measured as EC50 in acute toxicity tests), whereas exposure to atrazine under conditions that were either P-limited or non-P-limited clearly reduced the development of algal biomass. Long-term exposure to atrazine induced tolerance of the community to the herbicide, and this was not influenced by P addition. Tolerance induction in this microcosm experiment has been compared with previously published field data from the same area of study and indicates that tolerance induction by atrazine may take place under atrazine exposure in streams as well as in microcosms.

Peptides and hydrolysates from casein and soy protein modulate the release of vasoactive substances from human aortic endothelial cells.

Food proteins were shown to affect atherogenic risk factors, which is supposed to be related to specific peptide sequences encrypted within their primary sequence. The aim of this study was to evaluate the effects of peptides and hydrolysates from two food proteins, casein and soy protein, on endothelial cell functions (cell proliferation and release of vasoactive substances). Cell proliferation was not influenced by dipeptides and most of the tripeptides, whereas several total hydrolysates from casein and soy protein inhibited cell proliferation at higher concentrations (>0.25 mg/mL; P<0.05). The release of one or more of the vasoactive substances, thromboxan B2 (stable marker of thromboxan A2), 6-keto-prostaglandin F1alpha (stable marker of prostaglandin I2), endothelin-1, and nitric oxide, was significantly influenced by the incubation with various peptides compared with control cells (P<0.05). Various hydrolysate fractions from casein and soy protein influenced the release of 6-keto-prostaglandin F1alpha and nitric oxide (P<0.05) but did not influence the release of thromboxan B2 and endothelin-1. In conclusion, the present study demonstrates that peptides and hydrolysate fractions from casein and soy protein influence endothelial cell function as evidenced by the modulation of endothelial cell proliferation and alterations in the release of vasoactive substances.

Epidemiology and clinical features of vivax malaria imported to Europe: sentinel surveillance data from TropNetEurop.

BACKGROUND: Plasmodium vivax is the second most common species among malaria patients diagnosed in Europe, but epidemiological and clinical data on imported P. vivax malaria are limited. The TropNetEurop surveillance network has monitored the importation of vivax malaria into Europe since 1999. OBJECTIVES: To present epidemiological and clinical data on imported P. vivax malaria collected at European level. MATERIAL AND METHODS: Data of primary cases of P. vivax malaria reported between January 1999 and September 2003 were analysed, focusing on disease frequency, patient characteristics, place of infection, course of disease, treatment and differences between network-member countries. RESULTS: Within the surveillance period 4,801 cases of imported malaria were reported. 618 (12.9%) were attributed to P. vivax. European travellers and immigrants were the largest patient groups, but their proportion varied among the reporting countries. The main regions of infection in descending order were the Indian subcontinent, Indonesia, South America and Western and Eastern Africa, as a group accounting for more than 60% of the cases. Regular use of malaria chemoprophylaxis was reported by 118 patients. With 86 (inter-quartile range 41-158) versus 31 days (inter-quartile range 4-133) the median symptom onset was significantly delayed in patients with chemoprophylaxis (p < 0.0001). Common complaints were fever, headache, fatigue, and musculo-skeletal symptoms. All patients survived and severe clinical complications were rare. Hospitalization was provided for 60% and primaquine treatment administered to 83.8% of the patients, but frequencies varied strongly among reporting countries. CONCLUSIONS: TropNetEurop data can contribute to the harmonization of European treatment policies.

[Cirurgia Taurina--emergency medical treatment of bullfighters in Spain]. / Cirurgia Taurina. Die medizinische Versorgung der Toreros in Spanien.

A considerable risk of life-threatening injury is inherent to bullfighting. Thus, a unique form of emergency treatment has evolved over recent decades of organized bull-fighting. Today bullfight arenas in larger cities are equipped with emergency facilities including fully furnished operating rooms. During a fiesta these facilities are run by a medical team consisting of three surgeons, one intensive care specialist, and one anesthesiologist with their supporting medical personnel. In smaller arenas or villages immediate care units consist of emergency vehicles, and a mobile container equipped with a fully functional operating room. Of all toreros the matadores including the novilleros are most often injured in 56 % of cases. This rate decreases for banderillos (30 %), and for picadores (14 %). Parts of the body that are most frequently affected are thighs, and the inguinal region (54 %). Head and neck injuries are seen in 19 %, and 12 % of cases present with open abdominal wounds including liver or gastrointestinal tract traumas. 10 % of injuries affect the thorax, and 4 % the pelvic floor. The particular form of organised medical treatment for bullfighters in Spain has only developed since the nineteen-thirties. In 1972 a scientific society for bullfight surgery was founded in Spain by specialized surgeons, and immediate care specialists holding a first convention that year. The society is continuously striving to improve technical and logistical aspects of immediate medical care for injured bullfighters.

Quantitative MR renography using a calibrated internal signal (ERETIC).

To measure MR renograms, cortical and medullary kidney signal intensity evolution is followed after contrast agent injection. To obtain an accurate quantitative signal measurement, the use of a reference signal is necessary to correct the potential MRI system variations in time. The ERETIC method (Electronic Reference To access In vivo Concentrations) provides an electronic reference signal. It is synthesized as an amplitude modulated RF pulse applied during the acquisition. The ERETIC method was as precise as the external tube reference method but presents major advantages like its free adjustability (shape, location and magnitude) to the characteristics of the organ studied as well as its not taking room inside the magnet. Even though ERETIC showed a very good intrinsic stability, systems' variations still affect its signal in the same way as real NMR signals are affected. This method can be easily implemented on any imaging system with two RF channels.

Effect of a short-term in vitro exposure to the marine toxin domoic acid on viability, tumor necrosis factor-alpha, matrix metalloproteinase-9 and superoxide anion release by rat neonatal microglia.

BACKGROUND: The excitatory amino acid domoic acid, a glutamate and kainic acid analog, is the causative agent of amnesic shellfish poisoning in humans. No studies to our knowledge have investigated the potential contribution to short-term neurotoxicity of the brain microglia, a cell type that constitutes circa 10% of the total glial population in the brain. We tested the hypothesis that a short-term in vitro exposure to domoic acid, might lead to the activation of rat neonatal microglia and the concomitant release of the putative neurotoxic mediators tumor necrosis factor-alpha (TNF-alpha), matrix metalloproteinases-2 and-9 (MMP-2 and -9) and superoxide anion (O2-). RESULTS: In vitro, domoic acid [10 microM-1 mM] was significantly neurotoxic to primary cerebellar granule neurons. Although neonatal rat microglia expressed ionotropic glutamate GluR4 receptors, exposure during 6 hours to domoic acid [10 microM-1 mM] had no significant effect on viability. By four hours, LPS (10 ng/mL) stimulated an increase in TNF-alpha mRNA and a 2,233 % increase in TNF-alpha protein In contrast, domoic acid (1 mM) induced a slight rise in TNF-alpha expression and a 53 % increase (p < 0.01) of immunoreactive TNF-alpha protein. Furthermore, though less potent than LPS, a 4-hour treatment with domoic acid (1 mM) yielded a 757% (p < 0.01) increase in MMP-9 release, but had no effect on MMP-2. Finally, while PMA (phorbol 12-myristate 13-acetate) stimulated O2- generation was elevated in 6 hour LPS-primed microglia, a similar pretreatment with domoic acid (1 mM) did not prime O2- release. CONCLUSIONS: To our knowledge this is the first experimental evidence that domoic acid, at in vitro concentrations that are toxic to neuronal cells, can trigger a release of statistically significant amounts of TNF-alpha and MMP-9 by brain microglia. These observations are of considerable pathophysiological significance because domoic acid activates rat microglia several days after in vivo administration.

Marine pharmacology in 1999: antitumor and cytotoxic compounds.

During 1999 marine antitumor pharmacology research involved researchers in Austria, Australia, England, France, Germany, Greece, Holland, Italy, Japan, Spain, Taiwan and the United States. Thirty six papers were published in peer-reviewed journals describing the antitumor and cytotoxic properties of 30 marine natural products belonging to four structural types, namely polyketides, terpenes, nitrogen-containing compounds and polysaccharides. The organisms yielding these bioactive marine compounds comprised a diverse group of marine animals, algae, fungi and bacteria. A variety of antitumor pharmacological studies were conducted with 17 marine natural products with established mechanisms of action in a number of experimental and clinical models. Didemnin B, a tunicate-derived depsipeptide with potent antitumor effects, completed a Phase II anticancer clinical trial which resulted indeterminate in respect to activity against human melanoma due to anaphylactoid reactions. In vitro cytotoxicity data with murine and human cell lines were reported for 14 novel marine chemicals with as yet undetermined mechanisms of action. This 1999 literature overview thus highlights the fact that the multinational effort aimed at the discovery of novel marine antitumor agents remained at the same level of research activity as during 1998.

Magnetic resonance microscopy at 17.6-Tesla on chicken embryos in vitro.

The non-destructive nature and the rapid acquisition of a three-dimensional image makes magnetic resonance microscopy (MRM) very attractive and suitable for functional imaging investigations. We explored the use of an ultra high magnetic field for MRM to increase image quality per image acquisition time. Improved image quality was characterized by a better signal-to-noise ratio (SNR), better image contrast, and higher resolution compared to images obtained at lower magnetic field strengths. Fixed chicken embryos at several stages of development were imaged at 7.0-T (300 MHz) and at 17.6-T (750 MHz). Maximum intensity projection resulted in three-dimensional vascular images with ample detail of the embryonic vasculature. We showed that at 750 MHz frequency, an image with approximately three times better SNR can be obtained by T1-weighting using a standard gadolinium contrast agent, compared to the same measurement at 300 MHz. The image contrast improved by around 20 percent and the contrast-to-noise ratio improved by almost a factor of 3.5. Smaller blood vessels of the vascular system were identified at the high field, which indicates a better image resolution. Thus, ultra high field is beneficial for MRM and opens new areas for functional imaging research, in particular when SNR, resolution, and contrast are limited by acquisition time.

Magnetic resonance microscopy of mouse embryos in utero.

Magnetic resonance microscopy (MRM) was used to study mouse embryonic development in utero. MRM is a non-invasive imaging technique to study normal and abnormal embryonic development. To overcome image blurring as a result of embryonic movement, fast imaging sequences were used (less than 1 min scanning time). Clear morphologic proton images were obtained by diffusion spin echo and by rapid acquisition with relaxation enhancement (RARE), revealing living mouse embryos with great anatomical detail. In addition, functional information about embryonic blood flow could be obtained, in the absence of a contrast agent. This was achieved by combining two imaging sequences, RARE and very fast gradient echo. We expect that MRM will soon become a feasible method to study longitudinally both normal and abnormal (transgenic) mouse development.

In vivo NMR micro-imaging of kidney and liver of mouse at 9.4 T.

NMR micro-images of the kidney and liver were measured at 9.4 T in intact mouse, schistosoma Mansoni-infected mouse, and lupus nephritis in an MRL/lpr mouse. High-field NMR imaging has the advantages of sensitivity, spatial resolution, and tissue contrasts based on longitudinal and transverse relaxations, magnetic susceptibility differences and blood flow.

Isolation and characterization of microcystins from a river nile strain of Oscillatoria tenuis Agardh ex Gomont.

The River Nile is the major source of drinking water in Egypt, however, increased eutrophication due to agricultural, municipal and industrial runoff has contributed to the growth of toxin producing cyanobacteria. This study describes the isolation and characterization of microcystins (MCYSTs), cyclic heptapeptide hepatotoxins, from a rare strain of Oscillatoria tenuis, isolated from the River Nile at Sohag province in July 1995. The MCYST concentration of laboratory-cultured O. tenuis strain E6 was found to be 0.3 mg/g freeze-dried weight determined by enzyme-linked immunosorbent assay (ELISA). Two microcystins, 1 and 2, were isolated from lyophilized cells using solid phase extraction and reversed-phase high performance liquid chromatography (HPLC). Structures were assigned based upon their amino acid analyses, electrospray ionization mass spectrometry (ESIMS, ESIMS-CID-MS), high resolution fast atom bombardment mass spectrometry, and nuclear magnetic resonance data ((1)H and (1)H COSY NMR). Toxin 1 was identified as MCYST-LR, and toxin 2, a new MCYST, as MCYST-LHArg ([L-homoarginine(4)]). Previous studies indicate that Oscillatoria agardhii strains produce demethylated MCYSTs (containing D-Asp and/or dehydroalanine). This is the first report of a toxic O. tenuis, strain E6, one which produces a fully methylated MCYST, MCYST-LR and a new L-homoarginine containing MCYST, MCYST-LHArg.

Induced metal tolerance in microbenthic communities from three lowland rivers with different metal loads

The response of microbenthic communities to sustained metal stress was studied in three lowland rivers with different levels of pollution. Tolerance against zinc and cadmium was determined in short-term toxicity tests with microbenthic assemblages colonizing glass discs. Photosynthetic activity served as an endpoint in tests for algae, whereas for bacteria thymidine incorporation was determined. For bacterial assemblages from unpolluted locations, EC50 values in short-term tests ranged between 6.7 and 56.2 &mgr;M zinc, and 8.7 and 25.5 &mgr;M cadmium, respectively. Bacterial assemblages from the two most polluted sites were significantly more tolerant for zinc (EC50: 994 &mgr;M and >1,000 &mgr;M) and cadmium (EC50: 218 &mgr;M and 154 &mgr;M). Results indicated a shift in community composition toward pollution-adapted organisms when a threshold concentration of 1 &mgr;M zinc is exceeded. Although an increasing community tolerance was also indicated for algae, EC50 values for microbenthic algae from all sites exceeded in most cases the highest metal concentrations tested (Zn: 1,000 &mgr;M; Cd: 320 &mgr;M). Since species composition of algal assemblages was found to change at much lower metal levels, it is concluded that short-term toxicity tests measuring photosynthesis inhibition do not reflect well the long-term effects of these metals. Toxic effects of metals on both algal and bacterial assemblages are attenuated by precipitation and complexing capacities of the biofilm.

Modulation of tumor necrosis factor-alpha-mediated cytotoxicity by changes of the cellular methylation state: mechanism and in vivo relevance.

A combination of adenosine (Ado) and homocysteine (Homo) enhances tumor necrosis factor (TNF)-alpha cytotoxicity in vitro and in vivo in several tumor cells. Ado and Homo at concentrations that enhanced TNF-alpha-mediated cytotoxicity accumulated S-adenosylhomocysteine (AdoHcy) and as consequence decreased the cellular methylation state, i.e. the ratio of S-adenosylmethionine to AdoHcy. This decrease led to inhibition of the isoprenylcysteine carboxyl methyltransferase (MTase), an enzyme that catalyzes carboxyl methylation of C-terminal cysteine residues on isoprenylated proteins. The effect of Ado and Homo on TNF-alpha cytotoxicity was at least partly mimicked by S-farnesylthioacetic acid, a selective inhibitor of the isoprenylcysteine carboxyl MTase, suggesting involvement of methylations of prenylated proteins in TNF-alpha-mediated cytotoxicity. Blockage of methylation reactions was associated with an enhancement of the TNF-alpha-induced disruption of the mitochondrial membrane potential (delta psi(m)). In nude mice, a combination of Ado, Homo and TNF-alpha led to TNF-alpha-induced hemorrhagic necrosis and growth inhibition of TNF-sensitive L929 tumors, whereas little effect was observed with TNF-alpha alone. Even more important, the TNF-resistant L929 M1 tumors were rendered TNF-sensitive by the combined action of Ado and Homo. We conclude that Ado and Homo together enhance the effectiveness of TNF-alpha in vitro and in vivo, results that may have therapeutic implications.