Mixture effects of pharmaceuticals carbamazepine, diclofenac and venlafaxine on Mytilus galloprovincialis mussel probed by metabolomics and proteogenomics combined approach

Exposure to single molecules under laboratory conditions has led to a better understanding of the mechanisms of action (MeOAs) and effects of pharmaceutical active compounds (PhACs) on non-target organisms. However, not taking the co-occurrence of contaminants in the environment and their possible interactions into account may lead to underestimation of their impacts. In this study, we combined untargeted metabolomics and proteogenomics approaches to assess the mixture effects of diclofenac, carbamazepine and venlafaxine on marine mussels (Mytilus galloprovincialis). Our multi-omics approach and data fusion strategy highlighted how such xenobiotic cocktails induce important cellular changes that can be harmful to marine bivalves. This response is mainly characterized by energy metabolism disruption, fatty acid degradation, protein synthesis and degradation, and the induction of endoplasmic reticulum stress and oxidative stress. The known MeOAs and molecular signatures of PhACs were taken into consideration to gain insight into the mixture effects, thereby revealing a potential additive effect. Multi-omics approaches on mussels as sentinels offer a comprehensive overview of molecular and cellular responses triggered by exposure to contaminant mixtures, even at environmental concentrations.

Early Biological Modulations Resulting from 1-Week Venlafaxine Exposure of Marine Mussels Mytilus galloprovincialis Determined by a Metabolomic Approach

There is growing evidence of the presence of pharmaceuticals in natural waters and their accumulation in aquatic organisms. While their mode of action on non-target organisms is still not clearly understood, their effects warrant assessment. The present study assessed the metabolome of the Mediterranean mussel (Mytilus galloprovincialis) exposed to a 10 µg/L nominal concentration of the antidepressant venlafaxine (VLF) at 3 time-points (1, 3, and 7 days). Over the exposure period, we observed up- or down-modulations of 113 metabolites, belonging to several metabolisms, e.g., amino acids (phenylalanine, tyrosine, tryptophan, etc.), purine and pyrimidine metabolisms (adenosine, cyclic AMP, thymidine, etc.), and several other metabolites involved in diverse functions. Serotonin showed the same time-course modulation pattern in both male and female mussels, which was consistent with its mode of action in humans, i.e., after a slight decrease on the first day of exposure, its levels increased at day 7 in exposed mussels. We found that the modulation pattern of impacted metabolites was not constant over time and it was gender-specific, as male and female mussels responded differently to VLF exposure.

Multi-omic approach to evaluate the response of gilt-head sea bream (Sparus aurata) exposed to the UV filter sulisobenzone

Sulisobenzone (BP-4) is one of the benzophenone type UV filters most frequently detected in aquatic ecosystems. As a suspected endocrine disrupting compound, scarce information is available yet about other molecular effects and its mechanism of action. Here, we used an integrated transcriptomic and metabolomic approach to improve the current understanding on the toxicity of BP-4 towards aquatic species. Gilt-head sea bream individuals were exposed at environmentally relevant concentrations (10 μg L^-1) for 22 days. Transcriptomic analysis revealed 371 differentially expressed genes in liver while metabolomic analysis identified 123 differentially modulated features in plasma and 118 in liver. Integration of transcriptomic and metabolomic data showed disruption of the energy metabolism (>10 pathways related to the metabolism of amino acids and carbohydrates were impacted) and lipid metabolism (5 glycerophospholipids and the expression of 3 enzymes were affected), suggesting oxidative stress. We also observed, for the first time in vivo and at environmental relevant concentrations, the disruption of several enzymes involved in the steroid and thyroid hormones biosynthesis. DNA and RNA synthesis was also impacted by changes in the purine and pyrimidine metabolisms. Overall, the multiomic workflow presented here increases the evidence on suspected effects of BP-4 exposure and identifies additional modes of action of the compounds that could have been overlooked by using single omic approaches.

Cyclooxygenase 2 messenger RNA levels in canine follicular cells: interrelationship with GDF-9, BMP-15, and progesterone

Cyclooxygenase 2 (COX-2) encoded by the Cox-2 gene within the periovulatory follicles is a critical mediator of oocyte development. Growth differentiation factor 9 (GDF-9) and bone morphogenetic protein 15 (BMP-15) participate in the modulation of certain target genes in the ovary, possibly influencing the Cox-2 gene expression. However, this relationship has not been characterized in canines. This study aimed to examine the possible relationships among BMP-15, GDF-9, progesterone, and Cox-2 gene expression in granulosa-cumulus cells in dogs. Granulosa cells from antral follicles and their corresponding cumulus-oocyte complexes and follicular fluid (FF) were separately obtained from 56 ovaries collected from adult bitches at estrus (n = 15) and proestrus (n = 13) after ovariohysterectomy. Total RNA extraction was performed in follicular cells, and Cox-2 gene expression was assessed by quantitative PCR analysis. Progesterone, BMP-15, and GDF-9 were determined in the FF samples using ELISA assays. Cumulus-oocyte complexes were subjected to in vitro maturation (IVM) with or without (control) recombinant GDF-9 and BMP-15. After 72 h of culture, Cox-2 transcript analyses were performed in cumulus cells via quantitative PCR. Data were evaluated by ANOVA. An increase (P < 0.05) in Cox-2 messenger RNA levels was observed in follicular cells from follicles at estrus with respect to those at proestrus. However, the levels of BMP-15 and GDF-9 in FF decreased (P < 0.05), whereas progesterone increased (P < 0.05) from the proestrus phase to the estrus phase. The expression of Cox-2 gene in cumulus cells was 4-fold greater (P < 0.01) than that in the control when both growth factors were added to the IVM culture. In conclusion, although BMP-15 together with GDF-9 appears to upregulate the levels of Cox-2 transcripts during IVM, the inverse relationship of these paracrine factors with Cox-2 gene expression and the positive correlation of progesterone with Cox-2 transcripts suggest that the high progesterone levels could be more relevant in the local mechanisms regulating the Cox-2 gene expression.

Building a network for multicenter, prospective research of central nervous system infections in South America: Process and lessons learned

Multicenter collaborative networks are essential for advancing research and improving clinical care for a variety of conditions. Research networks are particularly important for central nervous system infections, which remain difficult to study due to their sporadic occurrence and requirement for collection and testing of cerebrospinal fluid. Establishment of long-term research networks in resource-limited areas also facilitates diagnostic capacity building, surveillance for emerging pathogens, and provision of appropriate treatment where needed. We review our experience developing a research network for encephalitis among twelve hospitals in five Peruvian cities since 2009. We provide practical suggestions to aid other groups interested in advancing research on central nervous system infections in resource-limited areas.

Glucose Concentration in the Dialysate and Lipid Abnormalities in Chronic Hemodialysis Patients

In order to assess the effect of varying glucose concentrations on plasma lipids, we first compared the hormonal response of nine non-diabetic patients during dialysis with a high (200 mg/dl) and a low (100 mg/dl) glucose bath. Insulin and growth hormone production increased (p < 0.05) only with the high glucose bath, and no hemodynamic differences were noted during either dialyses. We then compared lipid profiles of 18 patients for 6 months, changing the glucose dialysate concentrations in each patient after three months. We found that all patients had hypertriglyceridemia, mild hypercholesterolemia, low HDL, normal LDL, and high VLDL cholesterol. We therefore conclude that episodic hyperinsulinemia and episodic excessive growth hormone secretion do not contribute significantly to the lipid abnormalities of the dialysis patients.

Approaches to aspects of optimisation of protection in diagnostic radiology in six continents

There has been an expansion in the use of x-ray imaging during the last 20 years. Effective arrangements for justification of exposures as well as for optimisation of protection are crucial. The amount of effort put into the latter, the way in which it is organised and the groups carrying this out vary across the globe. A simple survey of organisational arrangements relating to performance testing of x-ray equipment, management of patient dose and other aspects of implementing optimisation has been undertaken. A total of 137 completed survey forms were received from medical physicists in 48 countries. Results for individual countries from which more responses were received, or for groups of neighbouring ones, are compared to portray variations. Some performance testing of x-ray equipment was mandated in most countries (more than 90%), with the tests being performed primarily by hospital or private medical physicists, although other groups are involved. Testing of equipment prior to clinical use was generally high for most regions, but the frequency was lower in Latin America. There was considerable variation in the frequency and regularity of subsequent testing. The prevalence of patient dose surveys was high in Europe, but lower in other continents. Organisational arrangements for testing performance of x-ray equipment, patient dose surveys and implementing optimisation of protection in medical exposures across the globe can be divided into five main groups. Hospital medical physicists take the lead in western Europe and Australia with the involvement of radiographers. Private medical physicists test equipment in Brazil, the USA and New Zealand, and have some responsibility for optimisation in Brazil. University personnel have significant involvement, together with medical physicists in eastern Europe, but the extent of the coverage is uncertain. Government personnel and service engineers carry out equipment testing in many countries of Africa and Asia, while radiographers have a significant role in Thailand and other countries where the number of medical physicists is limited. In order for dose surveys to have an impact, action must be taken upon the findings, but there must be an effective link between surveyors and radiology facility staff to ensure that this is done.

Suppression of bone resorption from odanacatib, a cathepsin K inhibitor, in women with bone metastases from breast cancer, and the effect of concomitant anti-neoplastic treatment on efficacy: a 4-week, double-blind, randomized controlled trial

Abstract #1157

Background: In breast cancer patients with metastatic bone disease (MBD), an osteolytic process releases factors that sustain tumor cell survival and proliferation. Cathepsin (Cat) K inhibition suppresses osteolysis in preclinical models of MBD. This study assessed the efficacy and safety of odanacatib, a potent and reversible selective Cat K inhibitor, in reducing markers of bone resorption in women with breast cancer and MBD depending on concomitant anti-neoplastic treatment.&#x2028; Materials and Methods: Women with breast cancer and MBD were randomized (double-blind) to oral odanacatib 5 mg daily for 4 weeks or IV zoledronic acid (ZA) 4 mg given once at study initiation. Bone resorption was assessed by urinary N-telopeptide of type I collagen corrected for creatinine (uNTx). A post-hoc analysis of the influence of concomitant therapy (chemotherapy vs hormone therapy) on study medication effects on uNTx was also conducted. Adverse events (AE) were monitored throughout the 4-week study and up to 14 days after last dose.&#x2028; Results: 43 patients (mean age 60 yrs) received odanacatib (n=29) or ZA (n=14); 40 patients completed all 4 weeks of treatment. 12 (41%) and 17 (59%) patients on odanacatib and 6 (46%) and 7 (54%) patients on ZA received chemotherapy or hormone therapy, respectively; one patient was on both co-therapies and one patient on ZA was not on concomitant therapy. Results for the effect of study medication on uNTx as well as the effects of concomitant therapy on each treatment group are shown in the table; results for the full analysis set were similar. The most common reported AEs were nausea, vomiting, headache, and bone pain, and generally not attributed to study drug.&#x2028; Conclusions: In women with breast cancer and MBD, the Cat K inhibitor, odanacatib, suppressed markers of bone resorption after 4 weeks of treatment. Mean uNTx was decreased in both treatment groups. The effect on biomarkers observed in this study was seen irrespective of concomitant anti-neoplastic treatment. Odanacatib was generally safe and well tolerated. These results suggest that Cat K inhibition is a potentially important, novel therapeutic approach for treating MBD.&#x2028; &#x2028;

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1157.

Which patients are more likely to benefit from postoperative shed blood salvage after unilateral total knee replacement? An analysis of 581 consecutive procedures

INTRODUCTION

Requirements for allogeneic blood transfusion (ABT) after total knee replacement (TKR) are still high (30-50%), and salvage of unwashed filtered postoperative shed blood (USB) may represent an alternative to ABT. We evaluated that patients are more likely to benefit of USB reinfusion after TKR.

PATIENTS AND METHODS

Data from 581 consecutive primary TKR, managed with (reinfusion group, n = 382) or without (control group, n= 199) reinfusion of USB, were retrospectively reviewed.

RESULTS

Patients from reinfusion group received 119 +/- 88 ml of red blood cells from USB, without clinically relevant incidents, and showed a lower ABT rate (30.6% vs. 8.4%, for control and reinfusion groups, respectively; P = 0.001) (transfusion trigger, haemoglobin [Hb] < 9 g/dl). Differences in ABT rate between groups were significant for all preoperative Hb levels, except for Hb < or = 12 g/dl. A lower transfusion threshold (Hb < 8 g/dl) might have further decreased ABT rate (14.6% vs. 5.2%, respectively; P < 0.001), with differences being significant for preoperative Hb between 12 and 15 g/dl. There were no differences with respect to postoperative infection rate, but patients from reinfusion group had a shorter length of hospital stay (11 +/- 4 vs. 13 +/- 4 days, respectively; P= 0.001).

CONCLUSIONS

Return of USB after TKR seems to reduce the need for ABT, especially in patients with preoperative Hb between 12 and 15 g/dl. There is little benefit of USB reinfusion for patients with preoperative Hb > 15 g/dl, whereas patients with preoperative Hb < 12 g/dl would probably benefit from the combination of USB with some other blood-saving method.

Acupuncture-point stimulation for chemotherapy-induced nausea or vomiting

BACKGROUND

There have been recent advances in chemotherapy-induced nausea and vomiting using 5-HT(3) inhibitors and dexamethasone. However, many still experience these symptoms, and expert panels encourage additional methods to reduce these symptoms.

OBJECTIVES

The objective was to assess the effectiveness of acupuncture-point stimulation on acute and delayed chemotherapy-induced nausea and vomiting in cancer patients.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, PsycLIT, MANTIS, Science Citation Index, CCTR (Cochrane Controlled Trials Registry), Cochrane Complementary Medicine Field Trials Register, Cochrane Pain, Palliative Care and Supportive Care Specialized Register, Cochrane Cancer Specialized Register, and conference abstracts.

SELECTION CRITERIA

Randomized trials of acupuncture-point stimulation by any method (needles, electrical stimulation, magnets, or acupressure) and assessing chemotherapy-induced nausea or vomiting, or both.

DATA COLLECTION AND ANALYSIS

Data were provided by investigators of the original trials and pooled using a fixed effect model. Relative risks were calculated on dichotomous data. Standardized mean differences were calculated for nausea severity. Weighted mean differences were calculated for number of emetic episodes.

MAIN RESULTS

Eleven trials (N = 1247) were pooled. Overall, acupuncture-point stimulation of all methods combined reduced the incidence of acute vomiting (RR = 0.82; 95% confidence interval 0.69 to 0.99; P = 0.04), but not acute or delayed nausea severity compared to control. By modality, stimulation with needles reduced proportion of acute vomiting (RR = 0.74; 95% confidence interval 0.58 to 0.94; P = 0.01), but not acute nausea severity. Electroacupuncture reduced the proportion of acute vomiting (RR = 0.76; 95% confidence interval 0.60 to 0.97; P = 0.02), but manual acupuncture did not; delayed symptoms for acupuncture were not reported. Acupressure reduced mean acute nausea severity (SMD = -0.19; 95% confidence interval -0.37 to -0.01; P = 0.04) but not acute vomiting or delayed symptoms. Noninvasive electrostimulation showed no benefit for any outcome. All trials used concomitant pharmacologic antiemetics, and all, except electroacupuncture trials, used state-of-the-art antiemetics.

AUTHORS' CONCLUSIONS

This review complements data on post-operative nausea and vomiting suggesting a biologic effect of acupuncture-point stimulation. Electroacupuncture has demonstrated benefit for chemotherapy-induced acute vomiting, but studies combining electroacupuncture with state-of-the-art antiemetics and in patients with refractory symptoms are needed to determine clinical relevance. Self-administered acupressure appears to have a protective effect for acute nausea and can readily be taught to patients though studies did not involve placebo control. Noninvasive electrostimulation appears unlikely to have a clinically relevant impact when patients are given state-of-the-art pharmacologic antiemetic therapy.

Dental treatment for children with chronic idiopathic thrombocytopaenic purpura: a report of two cases

Idiopathic thrombocytopaenic purpura (ITP) is the most common acquired bleeding disorder occurring in previously healthy children. The condition is benign and self-limiting, with a high possibility of recovery. Only 15-30% of children with acute ITP develop the chronic form. Clinically, ITP presents with petechiae, ecchymoses, haematomas, epistaxis, haematuria, mucocutaneous bleeding, and occasionally, haemorrhage into tissues. Oral manifestations include spontaneous gingival bleeding, petechiae or haematomas of the mucosa, tongue or palate. Two paediatric case reports are described concerning female patients diagnosed with chronic ITP. Oral findings and dental procedures are described. Standard dental treatment was performed with a platelet count higher than 50,000/mm3. The importance of adequate dental plaque control techniques in order to prevent inflammation, potential bleeding and infection in these patients is emphasized. The paediatric dentist must be aware of the clinical appearance of ITP in order to recognize the condition and successfully manage the patient.

Microglia-astrocyte interaction in Alzheimer's disease: friends or foes for the nervous system?

Brain glial cells secrete several molecules that can modulate the survival of neurons after various types of damage to the CNS. Activated microglia and astrocytes closely associate to amyloid plaques in Alzheimer Disease (AD). They could have a role in the neurotoxicity observed in AD because of the inflammatory reaction they generate. There is controversy regarding the individual part played by the different glial cells, and the interrelationships between them. Both astrocytes and microglia produce several cytokines involved in the inflammatory reaction. Moreover, the same cytokines may have different effects, depending on their concentration and the type of cells in the vicinity. In turn, the events occurring in response to injury may lead to changes in the nature and relative concentration of the various factors involved. To learn about these putative glial interrelationships, we examined some effects of astrocytes on microglial activation.

Design and implementation of a measuring campaign to model pesticide impacts in an Ecuadorian watershed

The first important issue in pesticide assessment for a watershed is the availability of soil and water quality information in the form of charts, maps or records. However, developing countries generally do not have enough historical data. Thus, sampling programs are crucial for the success of the evaluation, although in developing countries they always represent a controversial task between limited available budget and a precise assessment. This paper shows the steps taken to generate soil and water data to be used in a pesticide assessment project for a 34,000 ha watershed in Ecuador, South America. Sampling campaigns are still being run, so the methodology and the first results are shown here.

Magnetic resonance imaging of the normal equine brain

The purpose of this investigation was to define the magnetic resonance (MR) imaging appearance of the brain and associated structures of the equine head. MR images were acquired in oblique dorsal (T2-weighted), sagittal (T1-weighted), and transverse planes (T2-weighted), using a magnet of 1.5 Tesla and a human body coil. Relevant anatomic structures were identified and labeled at each level. The resulting images provided excellent anatomic detail of the cranioencephalic structures. Annotated MR images from this study are intended as a reference for clinical imaging studies of the equine head, specially in the diagnosis of brain diseases in the horse.

Rhegmatogenous retinal detachment in myopic eyes after laser in situ keratomileusis

PURPOSE

To report the characteristics and frequency of rhegmatogenous retinal detachment (RRD) after laser in situ keratomileusis (LASIK) for the correction of myopia in a large case series.

SETTING

Private practices, Caracas, Venezuela.

METHODS

Five refractive surgeons and 31 739 myopic eyes that had surgical correction of a mean myopia of -6.01 diopters (D) (range -0.75 to -29.00 D) participated in this study. Laser in situ keratomileusis was performed in all eyes. Patients were followed for a mean of 36 months (range 6 to 48 months). The clinical charts of patients who developed RRD after LASIK were reviewed.

RESULTS

Twenty eyes (17 patients) developed RRD after LASIK. Rhegmatogenous retinal detachments occurred a mean of 13.9 months (range 1 to 36 months) after LASIK. The mean pre-LASIK myopia in eyes that developed an RRD was -7.02 D (range -1.50 to -16.00 D). Most RRDs and retinal breaks occurred in the temporal quadrants (71.4%). Rhegmatogenous retinal detachments were managed with vitrectomy, cryoretinopexy, scleral buckling, argon laser retinopexy, or pneumatic retinopexy techniques. The frequency of RRD after LASIK was 0.06%.

CONCLUSIONS

Rhegmatogenous retinal detachment after LASIK for the correction of myopia is infrequent. If managed promptly, RRD will result in good vision. Before LASIK is performed, patients should have a thorough dilated indirect fundoscopy with scleral depression and treatment of any retinal lesion predisposing to the development of an RRD.

Garlic shows promise for improving some cardiovascular risk factors

OBJECTIVES

To summarize the effects of garlic on several cardiovascular-related factors and to note its adverse effects.

METHODS

English and non-English citations were identified from 11 electronic databases, references, manufacturers, and experts from January 1966 through February 2000 (depending on the database searched). Reports of cardiovascular-related effects were limited to randomized controlled trials lasting at least 4 weeks. Reports of adverse effects were not limited by study design. From 1798 pertinent records, 45 randomized trials and 73 additional studies reporting adverse events were identified. Two physicians abstracted outcomes and assessed adequacy of randomization, blinding, and handling of dropouts. Standardized mean differences of lipid outcomes from placebo-controlled trials were adjusted for baseline differences and pooled using random effects methods.

RESULTS

Compared with placebo, garlic preparations may lead to small reductions in the total cholesterol level at 1 month (range of average pooled reductions, 0.03-0.45 mmol/L [1.2-17.3 mg/dL]) and at 3 months (range of average pooled reductions 0.32-0.66 mmol/L [12.4-25.4 mg/dL]), but not at 6 months. Changes in low-density lipoprotein levels and triglyceride levels paralleled total cholesterol level results; no statistically significant changes in high-density lipoprotein levels were observed. Trials also reported significant reductions in platelet aggregation and mixed effects on blood pressure outcomes. No effects on glycemic-related outcomes were found. Proven adverse effects included malodorous breath and body odor. Other unproven effects included flatulence, esophageal and abdominal pain, allergic reactions, and bleeding.

CONCLUSIONS

Trials suggest possible small short-term benefits of garlic on some lipid and antiplatelet factors, insignificant effects on blood pressure, and no effect on glucose levels. Conclusions regarding clinical significance are limited by the marginal quality and short duration of many trials and by the unpredictable release and inadequate definition of active constituents in study preparations.

Rhegmatogenous retinal detachment after laser-assisted in situ keratomileusis (LASIK) for the correction of myopia

PURPOSE

To report a case series of rhegmatogenous retinal detachment (RRD) after laser-assisted in situ keratomileusis (LASIK) and its incidence at a mean of 24 months.

METHODS

The clinical charts of patients who experienced RRD after LASIK were reviewed. Five refractive surgeons and 24,890 myopic eyes that underwent surgical correction of myopia ranging from -0.75 to -29.00 diopters (D) (mean, -6.19 D) participated in this study.

RESULTS

Thirteen eyes from 12 patients developed RRD after LASIK. Rhegmatogenous RD occurred between 1 and 36 months (mean, 12.6 months) after LASIK. Eyes that developed RRD had from -1.50 to -16.00 D of myopia (mean, -6.96 D) before LASIK. Rhegmatogenous RD were managed with vitrectomy, cryoretinopexy, scleral buckling, argon laser retinopexy, or pneumatic retinopexy techniques. The incidence of RRD at a mean of 24 months after LASIK in this study was 0.05%.

CONCLUSIONS

Rhegmatogenous RD after LASIK is infrequent. If managed promptly, good vision can result. No cause-effect relationship between LASIK and RD can be proved from this study, but the authors recommend that patients scheduled for refractive surgery undergo a thorough dilated indirect fundus examination with scleral depression and treatment of any retinal lesions predisposing them to the development of RRD before LASIK surgery is performed.

Cl(-)-dependent excitotoxicity is associated with 3H2O influx in chick embryonic retina

The aim of this study was to show that Cl(-)-dependent excitotoxicity, with its characteristic cell swelling, involves actual water influx into the intracellular compartment. Taking advantage of the Ca2+ omission paradigm of Cl(-)-dependent excitotoxicity, in the chick embryonic neural retina ex vivo, which is associated with toxicity levels (lactate dehydrogenase (LDH) release) considerably higher than those seen after simple exposure of the retinas to glutamate agonists, we have demonstrated that an intracellular water intake of 4.2 microl into retinal cells is associated with 13.3% total retinal LDH release. The fact that mannitol blocks both water inflow and LDH release appears to link both events from a pathogenic point of view.

Ca2+-dependent kainate excitotoxicity in the chick embryonic neural retina ex vivo

The chick embryonic neural retina ex vivo has been singled out as a unique example of Cl(-)-dependent/Ca2+-independent excitotoxicity. However, after continuous incubation with 100 microM kainate, we have demonstrated the susceptibility of the chick retina to Ca2+-mediated damage, which becomes apparent after 12 h of exposure to the agonist in the absence of Cl-. Of the 20.8% lactate dehydrogenase released after 24 h incubation with kainate, some 11% is Cl(-)-dependent and the rest (9.8%) is presumably Ca2+-dependent. Upon omission of both Cl- and Ca2+, a 5% residual toxicity can still be detected after 24 h. This can be overcome by inclusion of EGTA in the incubation medium to neutralize Ca2+ released during incubation. A Ca2+-dependent toxicity mechanism is then operative in the embryonic chick retina ex vivo.

The validity of health claims on the World Wide Web: a systematic survey of the herbal remedy Opuntia

PURPOSE

The World Wide Web has become a significant source of health information for the public, but there is concern that much of the information is inaccurate, misleading, and unsupported by scientific evidence. To explore this issue, the validity of health claims for the herb Opuntia on the World Wide Web was analyzed.

DATA SOURCES

From December 1998 to May 1999, health claims were identified from Web sites utilizing nine search engines. A corresponding search was conducted of the scientific literature. Search terms included common and botanical names for Opuntia.

INCLUSION AND EXCLUSION CRITERIA

Nutritional support guidelines for herbs were used to identify claims from relevant sites. Scientific studies included established methodological designs with no restrictions on source, language, type of subjects, or dosage forms for Opuntia.

DATA EXTRACTION METHODS

A checklist of significant information was prepared for Web sites and scientific studies. The quality of scientific studies was assessed with two instruments, the Jadad and the Journal of the American Medical Association (JAMA) scales.

DATA SYNTHESIS

Validity of health claims on Web sites was compared with scientific reports. Searches retrieved 184 Web sites, 98 with health claims and 51 with research studies. Only 34% of the claims were addressed in the scientific literature, and evidence was conflicting or contradictory. For human studies, none met the criteria for high quality as determined by the Jadad and JAMA scales.

MAJOR CONCLUSIONS

The majority of health claims were based on folklore or indirect scientific evidence and could not be validated by scientific research. This suggests a need to check the validity of herbal information on the World Wide Web.

Incidence of vitreoretinal pathologic conditions within 24 months after laser in situ keratomileusis

OBJECTIVE

To report for the first time a case series of vitreoretinal pathologic conditions after laser in situ keratomileusis (LASIK) and to determine its incidence.

DESIGN

Case series.

PARTICIPANTS

Five refractive surgeons and 29,916 eyes that underwent surgical correction of ametropia (83.2% were myopic) ranging from -0.75 to -29.00 diopters (D; mean: -6.19 D) and from +1.00 to +6.00 D (mean: +3.23 D) participated in this retrospective study.

MAIN OUTCOME MEASURES

Vitreoretinal complications after LASIK.

RESULTS

The clinical findings of 20 eyes (17 patients) with LASIK-related vitreoretinal pathologic conditions are presented. Fourteen eyes experienced rhegmatogenous retinal detachments (RDs). Two eyes experienced corneoscleral perforations with the surgical microkeratome when a corneal flap was being performed (one experienced a vitreous hemorrhage and the other later experienced an RD). In four eyes, retinal tears without RDs were found. In one eye, a juxtafoveal choroidal neovascular membrane (CNVM) developed. Retinal tears were treated with argon laser retinopexy or cryotherapy. Corneoscleral perforations were sutured, and the RD was managed with vitrectomy. The remaining RDs were managed with vitrectomy, cryoretinopexy, scleral buckling, argon laser retinopexy, or pneumatic retinopexy techniques. The CNVM was surgically removed. The incidence of vitreoretinal pathologic conditions determined in our study was 0.06%.

CONCLUSIONS

Serious complications after LASIK are infrequent. Vitreoretinal pathologic conditions, if managed promptly, will still result in good vision. It is very important to inform patients that LASIK only corrects the refractive aspect of myopia. Complications of the myopic eye will persist.

Homeopathy and rheumatic disease

Despite a growing interest in uncovering the basic mechanisms of arthritis, medical treatment remains symptomatic. Current medical treatments do not consistently halt the long-term progression of these diseases, and surgery may still be needed to restore mechanical function in large joints. Patients with rheumatic syndromes often seek alternative therapies, with homeopathy being one of the most frequent. Homeopathy is one of the most frequently used complementary therapies worldwide.

Impact of study quality on outcome in placebo-controlled trials of homeopathy

We investigated the influence of indicators of methodological quality on study outcome in a set of 89 placebo-controlled clinical trials of homoeopathy in three different ways: (1) The results of studies meeting single criteria (explicit statement of random allocation, allocation concealment, double-blinding, completeness of follow-up) of methodological quality were compared with those of studies not meeting the criteria in univariate and multivariate analyses; (2) The results of studies scoring above and below predefined scores in two quality assessment scales were compared; (3) Primary studies were consecutively entered into a cumulative meta-analysis according to the summary scores derived from the quality assessment scales. All analyses were performed using meta-regression methods. Studies that were explicitly randomized and were double-blind as well as studies scoring above the cut-points yielded significantly less positive results than studies not meeting the criteria. In the cumulative meta-analyses, there was a trend for increasing effect sizes when more studies with lower-quality scores were added. However, there was no linear relationship between quality scores and study outcome. We conclude that in the study set investigated, there was clear evidence that studies with better methodological quality tended to yield less positive results. Because summarizing disparate study features into a single score is problematic, meta-regression methods simultaneously investigating the influence of single study features seem the best method for investigating the impact of study quality on outcome.

Aquaporin-1 expression in proximal tubule epithelial cells of human kidney is regulated by hyperosmolarity and contrast agents

Primary cells of renal proximal tubule epithelium (S1 segment) of human kidney (HRPTE cells) up-regulate aquaporin-1 (AQP-1) expression in response to hyperosmolarity. NaCl and D(+)-raffinose increased (2-2.5 fold) AQP-1 expression when medium osmolarity was 400 and 500 mOsm/kg.H2O. Urea did not have this effect. Unlike our previous findings with mIMCD-3 cells, vasopressin (10(-8)M) did not affect AQP-1 expression in HRPTE cells in isosmolar or NaCl-enriched hyperosmolar conditions. Furthermore, HRPTE cells increased (3-4 fold) AQP-1 expression when exposed to hyperosmolar Reno-60 and Hypaque-76 (diatrizoates, ionic) contrast agents at 400 and 500 mOsm/kg.H2O. Isosmolar (290 mOsm/kg H2O) Visipaque (iodixanol, non-ionic) at 10% (v/v) concentrations also increased AQP-1 expression, and 25% v/v of Visipaque rendered morphological alterations of HRPTE cells and a 3-fold increase in AQP-1 expression after 24h exposure. Finally, semi-quantitative RT-PCR of HRPTE cells subjected to various isosmolar or hyperosmolar conditions demonstrated up-regulation of AQP-1 mRNA and protein levels. Our results suggest AQP-1 up-regulation in HRPTE cells exposed to environmental stresses such as hyperosmolarity and high doses of isosmolar contrast agents.

High altitude living: genetic and environmental adaptation

High altitude (HA) living produces physiological changes for adaptation to chronic hypobaric-hypoxemic conditions. Although much is known about these physiologic adaptations, no clear separation has been made regarding what is "native" or "genetic" adaptation and what is "acquired." In this review, we describe the genetic vs. acquired adaptation and only include studies performed in a population native to HA and not in an acclimatized population or trekkers. The changes encountered in animals and humans living at HA in terms of hematology, muscular, respiratory, cerebral, cardiovascular, hormonal, fluid and electrolytes and reproduction, strongly suggest that genetics play a very important role in HA adaptation. Unfortunately, the characteristic physiology of HA natives has not been systematically defined to established specific measurable parameters of adaptation in comparison to the acquired ambient adaptation of the non-native population. Once the parameters are established, we can compare non-native populations exposed to HA that must emulate the HA physiology for a definite adaptation to be present. With measurable parameters, especially in the management of fluids and electrolytes, we can define how long it will take for a sea level native to adapt to an HA altitude. Until these studies are performed, speculation will continue and no rational medical intervention can be offered to HA newcomers who may experience HA difficulties.

Mayaro virus disease: an emerging mosquito-borne zoonosis in tropical South America

This report describes the clinical, laboratory, and epidemiological findings on 27 cases of Mayaro virus (MV) disease, an emerging mosquito-borne viral illness that is endemic in rural areas of tropical South America. MV disease is a nonfatal, dengue-like illness characterized by fever, chills, headache, eye pain, generalized myalgia, arthralgia, diarrhea, vomiting, and rash of 3-5 days' duration. Severe joint pain is a prominent feature of this illness; the arthralgia sometimes persists for months and can be quite incapacitating. Cases of two visitors from the United States, who developed MV disease during visits to eastern Peru, are reported. MV disease and dengue are difficult to differentiate clinically.

Experimental observation of interfering Bessel beams

We experimentally verified the interference resulting of the superposition of two Bessel beams propagating in free space and showed for first time the self imaging effect using nondiffracting beams. Our results are supported by numerical simulations and possible applications are discussed.