Comparison of the Efficacy and Safety of two Formulations of Diclofenac Sodium 0.1 % Eyedrops in Controlling Postoperative Inflammation after Cataract Surgery

PURPOSE

To compare the efficacy and safety of diclofenac sodium 0.1% eyedrops packaged in an Abak multidose container without preservative (Dicloabak) with the reference product, sodium merthiolate-preserved diclofenac sodium 0.1% eyedrops, in controlling postoperative inflammation after cataract surgery.

METHODS

The multicenter, controlled, randomized, single-masked study included 194 patients (Dicloabak 96, preserved diclofenac 98) scheduled to have cataract surgery by phacoemulsification with foldable intraocular lens. All were evaluated preoperatively and postoperatively after 1, 7, and 28 days. Postoperative inflammation was measured by the total score of anterior chamber cells and flare. Ocular plin, conjunctival hyperemia and ciliary flush were also assessed. Postoperative patient assessments also included visual acuity, objective tolerance by slit-lamp, fluorescein test, and subjective evaluation of local tolerance.

RESULTS

There was no statistically significant difference between the groups in the total score of flare and cells or the degree of conjunctival hyperemia and ciliary flush at any study visit. Dicloabak was demonstrated to be not inferior to preserved diclofenac at all assessment times. The overall assessment of local tolerance was similar for both study medications.

CONCLUSIONS

Preservative suppression did not alter diclofenac efficacy. Results support the good safety profile of both formulations when dosed three times daily for 4 weeks in absence of concomitant use of drugs potentially toxic for cornea. Preservative-free formulations like Dicloabak should be preferred to generic diclofenac formulations including other ingredients and may improve the safety profile of this topical nonsteroid anti-inflammatory drug.

[THE CORRECTION OF THE LOCAL IMMUNE RESPONSE AT THE PATIENTS WITH HELICOBACTER PYLORI INFECTION]

INTRODUCTION

Helicobacter pylori infection is due to the high prevalence in population attracts the clinical interest of researchers in the whole World. It is well known that this microorganism not only resides in the mucosa of the gastrointestinal tract, but is also defined in the periodontal pocket of the oral cavity. THE AIM OF INVESTIGATION: to evaluate Helicobacter pylori diagnostics in the mouth and prove a method of relief of the inflammatory process by applying immunomodulator Imudon. RESULTS. On the basis of obtained results it was found that the inclusion of topical immunomodulator Imudon in the complex therapy of Helicobacter pylori-associated diseases leads to reduction of inflammatory potential through the decrease of the TNFα, IL-6 activity in saliva and to increase the protective properties of saliva as a result of increased levels of mucin, significantly reduces the frequency of relapses in the one year after therapy.

CONCLUSION

It is practically important to determine the effectiveness of eradication therapy by the study of the contents of the tooth-gingival pocket for the detection of genetic material of Helicobacter pylori, as well as to include in the complex therapy of Helicobacter pylori-associated diseases of the immune modulator Imudon.

Administration of thimerosal-containing vaccines to infant rhesus macaques does not result in autism-like behavior or neuropathology

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder. Some anecdotal reports suggest that ASD is related to exposure to ethyl mercury, in the form of the vaccine preservative, thimerosal, and/or receiving the measles, mumps, rubella (MMR) vaccine. Using infant rhesus macaques receiving thimerosal-containing vaccines (TCVs) following the recommended pediatric vaccine schedules from the 1990s and 2008, we examined behavior, and neuropathology in three brain regions found to exhibit neuropathology in postmortem ASD brains. No neuronal cellular or protein changes in the cerebellum, hippocampus, or amygdala were observed in animals following the 1990s or 2008 vaccine schedules. Analysis of social behavior in juvenile animals indicated that there were no significant differences in negative behaviors between animals in the control and experimental groups. These data indicate that administration of TCVs and/or the MMR vaccine to rhesus macaques does not result in neuropathological abnormalities, or aberrant behaviors, like those observed in ASD.

A case-control study evaluating the relationship between thimerosal-containing haemophilus influenzae type b vaccine administration and the risk for a pervasive developmental disorder diagnosis in the United States

Thimerosal is an organic mercury (Hg)-containing compound (49.55 % Hg by weight) historically added to many multi-dose vials of vaccine as a preservative. A hypothesis testing case-control study evaluated automated medical records in the Vaccine Safety Datalink (VSD) for organic Hg exposure from Thimerosal in Haemophilus influenzae type b (Hib)-containing vaccines administered at specific times within the first 15 months of life among subjects diagnosed with pervasive developmental disorder (PDD) (n = 534) in comparison to controls. The generally accepted biologically non-plausible linkage between Thimerosal exposure and subsequent diagnosis of febrile seizure (n = 5886) was examined as a control outcome. Cases diagnosed with PDD received significantly more organic Hg within the first 6 months of life (odds ratio (OR) = 1.97, p < 0.001) and first 15 months of life (OR = 3.94, p < 0.0001) than controls, whereas cases diagnosed with febrile seizure were no more likely than controls to have received increased organic Hg. On a per microgram of organic Hg basis, cases diagnosed with a PDD in comparison to controls were at significantly greater odds (OR = 1.0197, p < 0.0001) of receiving increasing organic Hg exposure within the first 15 months of life, whereas cases diagnosed febrile seizure were no more likely than controls (OR = 0.999, p > 0.20) to have received increasing organic Hg exposure within the first 15 months of life. Routine childhood vaccination is an important public health tool to reduce the morbidity and mortality associated with infectious diseases, but the present study provides new epidemiological evidence of a significant relationship between increasing organic Hg exposure from Thimerosal-containing vaccines and the subsequent risk of PDD diagnosis in males and females.

Thiomersal-containing vaccines - a review of the current state of knowledge

Thiomersal is an organomercury compound known for its antiseptic and antifungal properties and used as an antibacterial agent in pharmaceutical products, including vaccines and other injectable biological products. In recent years, concerns about the possible link between immunization with thiomersal-containing vaccines and autism development have grown. Many case-control and cohort studies have been conducted on a number of populations, and none of them have confirmed the hypothetical relation between thiomersal and increased risk of autism spectrum disorders (ASDs) development. It is also confirmed by the fact, that since 1999, number of thiomersal-containing vaccines used worldwide is decreasing year by year, while the prevalence of ASDs cases is rising. There are no contraindications to the use of vaccines with thiomersal in infants, children and non-pregnant women. The risk of serious complications associated with the development of diseases in unvaccinated individuals far outweighs the potential risk of adverse consequences associated with immunization with thiomersal-containing vaccines.

A comparative pharmacokinetic estimate of mercury in U.S. Infants following yearly exposures to inactivated influenza vaccines containing thimerosal

The use of thimerosal preservative in childhood vaccines has been largely eliminated over the past decade in the United States because vaccines have been reformulated in single-dose vials that do not require preservative. An exception is the inactivated influenza vaccines, which are formulated in both multidose vials requiring preservative and preservative-free single-dose vials. As part of an ongoing evaluation by USFDA of the safety of biologics throughout their lifecycle, the infant body burden of mercury following scheduled exposures to thimerosal preservative in inactivated influenza vaccines in the United States was estimated and compared to the infant body burden of mercury following daily exposures to dietary methylmercury at the reference dose established by the USEPA. Body burdens were estimated using kinetic parameters derived from experiments conducted in infant monkeys that were exposed episodically to thimerosal or MeHg at identical doses. We found that the body burden of mercury (AUC) in infants (including low birth weight) over the first 4.5 years of life following yearly exposures to thimerosal was two orders of magnitude lower than that estimated for exposures to the lowest regulatory threshold for MeHg over the same time period. In addition, peak body burdens of mercury following episodic exposures to thimerosal in this worst-case analysis did not exceed the corresponding safe body burden of mercury from methylmercury at any time, even for low-birth-weight infants. Our pharmacokinetic analysis supports the acknowledged safety of thimerosal when used as a preservative at current levels in certain multidose infant vaccines in the United States.

A historically-controlled Phase III study in adults to characterize the acceptability of a process change for manufacturing inactivated quadrivalent influenza vaccine

BACKGROUND

An inactivated quadrivalent influenza vaccine (QIV) was recently licenced in the US as a thimerosal-free formulation presented in a pre-filled syringe. A multidose presentation is preferred in some settings due to reduced acquisition and cold storage costs. We assessed the immunogenicity and safety of a thimerosal-containing QIV formulated using a new manufacturing process for presentation in multidose vials.

METHODS

Two Phase III non-randomized studies separately evaluated inactivated trivalent influenza vaccine (TIV; 2010-2011; historical control) and a QIV (2011-2012). The QIV contained the same strains as the TIV plus an additional B strain. Both vaccines contained thimerosal to allow multidose presentation: this preservative was added to the QIV during the final formulation step using a new process, whereas it was added to the TIV early in the manufacturing process using an established method. The TIV study included 50 and 70 subjects aged 18-60 and >60 years, respectively; the QIV study included 56 subjects in each age stratum. Immunogenicity was assessed using hemagglutination-inhibition (HI) assays. Reactogenicity was assessed during the 4-day post-vaccination periods and unsolicited adverse events (AEs) were assessed during the 21-day post-vaccination periods.

RESULTS

The TIV and QIV were immunogenic in both age strata. With the QIV and TIV respectively, the seroconversion rates were 48.2-62.7% and 71.4-83.7% for influenza A, and 33.9-62.5% and 67.3-72.9% for influenza B. With the QIV and TIV respectively, the seroprotection rates were 92.9-98.2% and 98.2-100% for influenza A, and 88.6-100% and 95.9-98.6% for influenza B. Pre-vaccination titers were higher in the QIV versus TIV study which confounds a direct comparison and likely explains the lower seroconversion rates observed in the QIV study. There were no safety concerns raised with TIV or QIV.

CONCLUSIONS

The thimerosal-containing QIV formulated using a new process was immunogenic, conforming to regulatory acceptance criteria, with a reactogenicity and safety profile in line with the TIV manufactured using a licensed process. These results support acceptability of a manufacturing process change in which the thimerosal preservative is added at the point at which batches are filled into multidose vials.

TRIAL REGISTRATION

These trials were registered at ClinicalTrials.gov: NCT01440387; NCT01153685.

Cutaneous leishmaniasis "chiclero's ulcer" in subtropical Ecuador

An 18-year-old female presented with a severe ulcerative lesion on her right ear of 6 weeks duration. Her right ear was edematous and erythematous with a large, painless ulcerative lesion covering a third of the pinna and satellite papular lesions on the posterior. She was diagnosed with chiclero's ulcer. A skin smear stained with Diff-quik showed abundant Leishmania parasites. Chiclero's ulcer is a rare clinical presentation and is typically severe and difficult to treat. Physicians in Ecuador recommend administering prolonged intramuscular Glucantime. Side effects are common and can be severe resulting in low patient compliance. Because of preferences of the patient and the large volume needed for her weight, we recommended topical treatment with a lotion of Glucantime mixed half and half with white Merthiolate. After applying this lotion to the lesion 3 to 4 times a day for 6 weeks, the lesion healed.

[Local immunomodulating agents in complex treatment of oral lichen planus]

The paper presents the results of local immunity status assessment in patients with erosive-ulcerous form of oral lichen planus by etiopatogenetic treatment including imudone and derinate. The positive dynamics of immunological parameters under imudone and derinate is demonstrated.

Total mercury content in canine hair before and after administration of vaccines containing thiomersal

OBJECTIVES

Thiomersal is ethylmercury containing compound. It has been used as a preservative in vaccines since the 1930s because it is very effective in preventing bacterial contamination. Ethylmercury penetrates into growing hair in a similar manner as methylmercury.

DESIGN

A total of 48 hair samples were collected from vaccinated dogs. Each sample was accompanied with a questionnaire including data on age, gender, vaccinations. Total mercury content in hair, granules and vaccines was determined by the direct method of cold vapours using an AMA 254 (advance mercury analyser; Altec Ltd., Czech Republic).

RESULTS

At first we performed two pre-experiments. In first pre-experiment, the highest value of total mercury content was 0.732 mg.kg-1. The content of total mercury ranged from 0.022 to 0.092 mg.kg-1 in the second pre-experiment. The results were not statistically significant in the pre-experiments. In the main experiment the lowest concentration of total mercury in dog's hair was 0.002 mg.kg-1 and the highest value was 0.560 mg.kg-1. The median value of total mercury ranged from 0.023 to 0.033 mg.kg-1. The results were not statistically significant in the main experiment. Total mercury content in vaccines corresponded with the declared quantity. Rather, results showed mercury content to be correlated with the consumption of feed containing fish.

CONCLUSIONS

Thiomersal preservative, contained in vaccine, does not increase content of total mercury in canine hair. Our results have shown that content of mercury in hair depends on fish consumption (fish granules, fish treats and fresh fish).

Administration of thimerosal to infant rats increases overflow of glutamate and aspartate in the prefrontal cortex: protective role of dehydroepiandrosterone sulfate

Thimerosal, a mercury-containing vaccine preservative, is a suspected factor in the etiology of neurodevelopmental disorders. We previously showed that its administration to infant rats causes behavioral, neurochemical and neuropathological abnormalities similar to those present in autism. Here we examined, using microdialysis, the effect of thimerosal on extracellular levels of neuroactive amino acids in the rat prefrontal cortex (PFC). Thimerosal administration (4 injections, i.m., 240 μg Hg/kg on postnatal days 7, 9, 11, 15) induced lasting changes in amino acid overflow: an increase of glutamate and aspartate accompanied by a decrease of glycine and alanine; measured 10-14 weeks after the injections. Four injections of thimerosal at a dose of 12.5 μg Hg/kg did not alter glutamate and aspartate concentrations at microdialysis time (but based on thimerosal pharmacokinetics, could have been effective soon after its injection). Application of thimerosal to the PFC in perfusion fluid evoked a rapid increase of glutamate overflow. Coadministration of the neurosteroid, dehydroepiandrosterone sulfate (DHEAS; 80 mg/kg; i.p.) prevented the thimerosal effect on glutamate and aspartate; the steroid alone had no influence on these amino acids. Coapplication of DHEAS with thimerosal in perfusion fluid also blocked the acute action of thimerosal on glutamate. In contrast, DHEAS alone reduced overflow of glycine and alanine, somewhat potentiating the thimerosal effect on these amino acids. Since excessive accumulation of extracellular glutamate is linked with excitotoxicity, our data imply that neonatal exposure to thimerosal-containing vaccines might induce excitotoxic brain injuries, leading to neurodevelopmental disorders. DHEAS may partially protect against mercurials-induced neurotoxicity.

[The use of immunocorrection therapy for the combined treatment of the inflammatory diseases of the pharynx]

The objective of the study. To estimate the efficacy of the combined treatment of the patients presenting with chronic tonsillitis, acute and chronic pharyngitis with the use of traditional methods supplemented by the immunocorrective preparation imudon. A total of 320 patients with inflammatory pharyngeal diseases were examined and treated. It was shown that the introduction of imudon therapy in the combined treatment of chronic tonsillitis, acute and chronic pharyngitis produces a more pronounce and stable beneficial effects than conventional therapy.

[Immunogenicity of inactivated subunit adsorbed monovalent vaccine against influenza A/California/7/2009 (H1N1) strain]

The immunogenicity of Pandeflu subunit vaccine against influenza A/California/7/2009 (H1N1) was evaluated in 70 healthy volunteers aged 18 to 60 years. The vaccine was intramuscularly injected twice at an interval of 28 days. Each dose (0.5 ml) contains A(HIN1) influenza virus hemagglutinin (15 +/- 2.2 microg), aluminum hydroxide (Denmark) (0.475 +/- 0.075 microg), and the preservative thiomerosal (merthiolate) (50 +/- 7.5 microg). The level of antibodies was determined in the microneutralization assay. After administration of two doses of the vaccine at a 28-day interval, the geometric mean antibody titer (GMAT) reached 1:21.1 with a further increase to 1:30 (the baseline GMAT) was 1:6.1). The frequencies of seroconversion and seroprotection were 71.4 and 59.2%, respectively; the antibody increase factor was 4.92, which meets the CPMP criteria. The administration of the vaccine did not result in adverse reactions in the postvaccination period.

[Dynamics of immunological characteristics and investigation of apoptosis of palatal tonsillar lymphocytes in patients presenting with chronic tonsillitis and treated by conservative therapy]

The enhanced amount of viable lymphocytes and the decreased number of apoptotic cells as well as the reduced levels of IgA and IgM and the elevated concentration of sIgA in lacunar secretion are considered to be the reliable criteria for the efficacy of the conservative treatment of chronic tonsillitis. Combined therapy of this condition including irrigation of the palatal tonsillar lacunae with a miramistin solution, their contact ultrasonic treatment, and application of imudon makes it possible to maintain the optimal ratio of viable to apoptotic lymphocytes during a period of up to 6-7 months.

Unusual delayed reaction after H1N1 vaccine

We reported a case of allergic contact dermatitis three weeks after the H1N1 vaccine, probably involving thimerosal additive. Patients should be aware of this possible unusual delayed reaction.

A prospective study of thimerosal-containing Rho(D)-immune globulin administration as a risk factor for autistic disorders

BACKGROUND

This study evaluated the relationship between prenatal mercury exposure from thimerosal (49.55% mercury by weight)-containing Rho(D)-immune globulins (TCRs) and autism spectrum disorders (ASDs).

METHODS

The Institutional Review Board of the Institute for Chronic Illnesses approved the present study. A total of 53 consecutive non-Jewish Caucasian patients with ASDs (Diagnostic and statistical manual of mental disorders, fourth ed. - DSM IV) born between 1987 and 2001 who presented to the Genetic Centers of America for outpatient genetic/developmental evaluations were prospectively collected from June 1, 2005 through March 31, 2006. Imaging and laboratory testing were conducted on each patient to rule out other causal factors for their ASDs. As race-matched controls, the frequency of Rh negativity was determined from 926 non-Jewish Caucasian pregnant women who had presented for outpatient prenatal genetics care to the Genetic Centers of America between 1980 and 1989.

RESULTS

Children with ASDs (28.30%) were significantly more likely (odds ratio 2.35, 95% confidence interval 1.17-4.52, p < 0.01) to have Rh-negative mothers than controls (14.36%). Each ASD patient's mother was determined to have been administered a TCR during her pregnancy.

CONCLUSION

The results provide insights into the potential role prenatal mercury exposure may play in some children with ASDs.

Time of perinatal immunization, thimerosal exposure and neurodevelopment at 6 months in breastfed infants

AIM

Brazilian newborns immunized with hepatitis-B (thimerosal containing vaccine, TCV) receive the first dose within 24 h if delivered in public hospitals, but at a later time if born in private hospitals. We compared neurodevelopment (ND) in infants born in a state hospital (immunized within 24 h) and in privately run hospitals (immunized 2-4 days postnatally).

METHODS

We used the Gesell Developmental Schedules in 82 healthy exclusively breastfed infants at 6 months to assess motor skills, language development, comprehension capacity and social skills.

RESULTS

Compared to the group immunized 2-4 days after hospital discharge, the group immunized within 24 h showed no significant difference in ND delays. Despite the variation in gestational age (range 36-42 weeks) and TCV-ethylmercury (EtHg) dose (5.7-11.3 microg Hg/kg b.w.) at birth, time of exposure to TCV showed no significant association with ND. Gesell Developmental Score was not significantly correlated with total parenteral EtHg/unit of body mass neither with the relative increase in hair-Hg (as an additional challenge to prenatal Hg exposure).

CONCLUSION

In breastfed infants, differences in early exposure to TCV-EtHg cannot portend clinical neurodevelopment delays at 6 months. We speculate that breastfeeding remains a significant strategy to improve central nervous system protection of infants facing early exposure challenges.

Perinatal hepatitis B transmission and vaccination timing in a managed care cohort: assessment of the temporary delay in newborn hepatitis B vaccination due to thimerosal content

BACKGROUND

From July to September 1999, due to a concern of toxicity from exposure to thimerosal-containing vaccines, the American Academy of Pediatrics and U.S. Public Health Service temporarily recommended delaying the administration of first dose of hepatitis B vaccine until the age of 2-6 months for infants born to hepatitis B surface antigen negative mothers. Our objectives were to determine whether the recommendation affected the rate of perinatal hepatitis B infection in a multistate managed care population; to describe neonatal and early childhood cases of hepatitis B infection and to evaluate a possible role of the recommendation; and to assess the timeliness, with respect to the U.S. childhood immunization schedule, of vaccinations during the first 2 years of life.

METHODS

We identified 3 cohorts of infants born before (July 1998 to June 1999), during (July 1999 to September 1999) and after (October 1999 to September 2000) the recommendation period. We used automated claims data to identify possible neonatal and early childhood hepatitis B cases using specific ICD-9 diagnosis and CPT procedure codes and validated cases through medical record review. Using Health Plan Employer Data and Information Set (HEDIS) data, we calculated vaccination coverage for the first dose of hepatitis B vaccine at 3-month intervals from January 1999 to September 2000.

RESULTS

The eligible populations in the "before," "during" and "after" cohorts were 29,347, 7791 and 29,215 infants, respectively. Of 41 possible hepatitis B cases identified in the 3 cohorts, we confirmed 1 case in the after cohort with medical record review. Despite receiving the first dose of hepatitis B vaccine and hepatitis B immunoglobulin within 12-24 hours of birth, the infant was diagnosed with laboratory-confirmed chronic hepatitis B at age of 9 months. An analysis of HEDIS data showed that vaccination coverage for the first dose of hepatitis B vaccine was 98% (January to March 1999) and 96% (April to June 1999) for the "before" cohort and 66% for the "during" cohort. For the "after" cohort the coverage was 72% (October to December 1999), 83% (January to March 2000), 91% (April to June 2000) and 95% (July to September 2000).

CONCLUSIONS

This study did not identify any perinatal hepatitis B transmission among health plan enrollees associated with the 1999 recommendation. The recommendation did result in a delay of hepatitis B birth dose in the "during" cohort as intended for infants born to hepatitis B surface antigen negative mothers. Six months after the recommendation was rescinded there was still a delay in the timing of first dose of hepatitis B vaccine, but the timing had returned to the prerecommendation level after 9-12 months.

Comparison of thiomersal-free and thiomersal-containing formulations of a recombinant hepatitis B vaccine (Hepavax-Gene®) in healthy adults

A thiomersal-free (TF) formulation of the recombinant hepatitis B vaccine Hepavax-Gene has been developed. This study compared immunogenicity and safety of Hepavax-Gene, Hepavax-Gene TF and Engerix-B (containing trace amounts of thiomersal) in a large healthy adult population (N=770) using two vaccination schedules: the priming 0-1-2 months or the standard 0-1-6 month schedule. Hepavax-Gene TF was non-inferior to Hepavax-Gene and Engerix-B with respect to seroprotection rates (>or=10I U/L) 1 month after the third vaccination using the 0-1-6 month schedule, with 99.1% for both Hepavax-Gene formulations and 100% for Engerix-B of subjects' seroprotected in each group. The seroprotection rate after the 0-1-2 schedule was 89.6% for Hepavax-Gene TF, lower than for Hepavax-Gene (94.2%) but comparable to Engerix-B (86.4%). Furthermore, Hepavax-Gene TF was as well tolerated as the comparator vaccines.

Mercury concentrations in brain and kidney following ethylmercury, methylmercury and Thimerosal administration to neonatal mice

The distribution of mercury to the brain following an injection of methylmercury (MeHg) or ethylmercury (EtHg) was examined in immature mice. Postnatal day (PND) 16 CD1 mice received MeHg chloride either by IM injection or by gavage. At 24 h and 7 days post-injection, total mercury concentrations were determined in blood, kidney, brain, and muscle by cold vapor atomic fluorescence spectrometry. At 24 h, an IM injection of MeHg chloride (17.4 microg) produced total mercury concentrations in the blood (6.2 +/- 0.9 microg/g), brain (5.6 +/- 1.3 microg; 0.6% delivered dose), and kidney (25.2 +/- 5.6 microg; 1.1%), approximately 30% of that obtained from oral administration (blood: 17.9 +/- 1.0 microg; brain: 16.1 +/- 1.2 microg, 1.5%; kidney: 64.9 +/- 6.3 microg, 2.7%). For comparison, PND 16 mice received an IM injection of concentrated dosing suspensions (2 microl dosing vol.) for EtHg chloride (6 microg) or Thimerosal (15.4 microg). For EtHg, approximately 0.39 +/- 0.06% of the injected mercury was detected in the brain and 3.5 +/- 0.6% in the kidney at 24 h. Thimerosal IM injection resulted in 0.22 +/- 0.04% in the brain, and 1.7 +/- 0.3% in the kidney. By 7 days, mercury levels decreased in the blood but were unchanged in the brain. An acute IM injection to adult mice of each suspension at a 10-fold higher dose resulted an average 0.1% mercury in the brain, and higher levels in the blood, kidney, and muscle as compared to the young. In immature mice, MeHg delivered via oral route of administration resulted in significantly greater tissue levels as compared to levels from IM injection. Comparisons of tissue distribution following IM administration suggest that an oral route of administration for mercury is not comparable to an IM delivery and that MeHg does not appear to be a good model for EtHg-containing compounds.

Thimerosal exposure in infants and developmental disorders: a prospective cohort study in the United kingdom does not support a causal association

OBJECTIVE

There is an established link between exposure to mercury and impaired childhood cognitive development and early motor skills. Thimerosal (also known as thiomersal), a preservative used in a number of children's vaccines, contains ethylmercury (an organic compound of mercury), and there has been concern that this exposure to mercury may be of some detriment to young children. The aim of this research was to test in a large United Kingdom population-based cohort whether there is any evidence to justify such concerns.

METHODS

We used population data from a longitudinal study on childhood health and development. The study has been monitoring >14,000 children who are from the geographic area formerly known as Avon, United Kingdom, and were delivered in 1991-1992. The age at which doses of thimerosal-containing vaccines were administered was recorded, and measures of mercury exposure by 3, 4, and 6 months of age were calculated and compared with a number of measures of childhood cognitive and behavioral development covering the period from 6 to 91 months of age.

RESULTS

Contrary to expectation, it was common for the unadjusted results to suggest a beneficial effect of thimerosal exposure. For example, exposure at 3 months was inversely associated with hyperactivity and conduct problems at 47 months; motor development at 6 months and at 30 months; difficulties with sounds at 81 months; and speech therapy, special needs, and "statementing" at 91 months. After adjustment for birth weight, gestation, gender, maternal education, parity, housing tenure, maternal smoking, breastfeeding, and ethnic origins, we found 1 result of 69 to be in the direction hypothesized-poor prosocial behavior at 47 months was associated with exposure by 3 months of age (odds ratio: 1.12; 95% confidence interval: 1.01-1.23) compared with 8 results that still supported a beneficial effect.

CONCLUSIONS

We could find no convincing evidence that early exposure to thimerosal had any deleterious effect on neurologic or psychological outcome.

Thimerosal exposure in infants and developmental disorders: a retrospective cohort study in the United kingdom does not support a causal association

OBJECTIVE

After concerns about the possible toxicity of thimerosal-containing vaccines in the United States, this study was designed to investigate whether there is a relationship between the amount of thimerosal that an infant receives via diphtheria-tetanus-whole-cell pertussis (DTP) or diphtheria-tetanus (DT) vaccination at a young age and subsequent neurodevelopmental disorders.

METHODS

A retrospective cohort study was performed using 109 863 children who were born from 1988 to 1997 and were registered in general practices in the United Kingdom that contributed to a research database. The disorders investigated were general developmental disorders, language or speech delay, tics, attention-deficit disorder, autism, unspecified developmental delays, behavior problems, encopresis, and enuresis. Exposure was defined according to the number of DTP/DT doses received by 3 and 4 months of age and also the cumulative age-specific DTP/DT exposure by 6 months. Each DTP/DT dose of vaccine contains 50 microg of thimerosal (25 microg of ethyl mercury). Hazard ratios (HRs) for the disorders were calculated per dose of DTP/DT vaccine or per unit of cumulative DTP/DT exposure.

RESULTS

Only in 1 analysis for tics was there some evidence of a higher risk with increasing doses (Cox's HR: 1.50 per dose at 4 months; 95% confidence interval [CI]: 1.02-2.20). Statistically significant negative associations with increasing doses at 4 months were found for general developmental disorders (HR: 0.87; 95% CI: 0.81-0.93), unspecified developmental delay (HR: 0.80; 95% CI: 0.69-0.92), and attention-deficit disorder (HR: 0.79; 95% CI: 0.64-0.98). For the other disorders, there was no evidence of an association with thimerosal exposure.

CONCLUSIONS

With the possible exception of tics, there was no evidence that thimerosal exposure via DTP/DT vaccines causes neurodevelopmental disorders.

Intérêt d’une nouvelle formulation de diclofénac sans conservateur pour la surface oculaire

AIM

To compare the ocular tolerance of nonpreserved diclofenac versus thiomersal-preserved diclofenac in healthy volunteers.

MATERIALS AND METHODS

Forty healthy volunteers instilled Dicloabak in the randomised eye and thiomersal-preserved diclofenac in the other eye, according to a strictly identical dosing regimen, for 28 days. Each volunteer thus served as his or her own control. The dose regimen was five drops/day for 7 days followed by three drops/day for 20 days. Ocular tolerance was assessed by the discomfort upon instillation (measured on a visual analogue scale [VAS]), subjective ocular symptoms following instillation (irritation/burning/stinging, eye dryness and foreign body sensation) and finally by an objective examination of the ocular surface. These criteria were evaluated on days 0, 14, 21 and 28.

RESULTS

The subjective ocular symptoms following instillation were significantly lower in the nonpreserved group at Day 7 and nearly significantly lower until the end of the study. The biomicroscopy exam confirmed that there was better tolerance without thiomersal. There was less follicular-papillary conjunctivitis and a significantly better lissamine green score in the Dicloabak group.

CONCLUSION

The results of this study demonstrate that the nonpreserved formulation of diclofenac is better tolerated by the ocular surface and thus constitutes a therapeutic benefit.

Dose–response study of thimerosal-induced murine systemic autoimmunity

The organic compound ethylmercurithiosalicylate (thimerosal), which is primarily present in the tissues as ethylmercury, has caused illness and several deaths due to erroneous handling when used as a disinfectant or as a preservative in medical preparations. Lately, possible health effects of thimerosal in childhood vaccines have been much discussed. Thimerosal is a well-known sensitizing agent, although usually of no clinical relevance. In rare cases, thimerosal has caused systemic immune reactions including acrodynia. We have studied if thimerosal might induce the systemic autoimmune condition observed in genetically susceptible mice after exposure to inorganic mercury. A.SW mice were exposed to 1.25-40 mg thimerosal/l drinking water for 70 days. Antinucleolar antibodies, targeting the 34-kDa protein fibrillarin, developed in a dose-related pattern and first appeared after 10 days in the two highest dose groups. The lowest observed adverse effect level (LOAEL) for antifibrillarin antibodies was 2.5 mg thimerosal/l, corresponding to an absorbed dose of 147 microg Hg/kg bw and a concentration of 21 and 1.9 microg Hg/g in the kidney and lymph nodes, respectively. The same LOAEL was found for tissue immune-complex deposits. The total serum concentration of IgE, IgG1, and IgG2a showed a significant dose-related increase in thimerosal-treated mice, with a LOAEL of 5 mg thimerosal/l for IgG1 and IgE, and 20 mg thimerosal/l for IgG2a. The polyclonal B-cell activation showed a significant dose-response relationship with a LOAEL of 10 mg thimerosal/l. Therefore, thimerosal induces in genetically susceptible mice a systemic autoimmune syndrome very similar to that seen after treatment with inorganic mercury, although a higher absorbed dose of Hg is needed using thimerosal. The autoimmune syndrome induced by thimerosal is different from the weaker and more restricted autoimmune reaction observed after treatment with an equipotent dose of methylmercury.

The thiol reagent, thimerosal, irreversibly inhibits meiosis reinitiation in mouse oocyte when applied during a very early and narrow temporal window: a pharmacological analysis

The effect of the sulfhydryl reagent, thimerosal (TMS) on meiosis resumption in germinal vesicle (GV)-stage denuded mouse oocytes was studied. It irreversibly inhibits both GV breakdown (GVBD) and the first polar body (pb1) extrusion in concentration- and time-dependent manners, the most striking result being the very early and narrow temporal window during which denuded primary oocytes released from their follicle are susceptible to a pulse of the drug. This inhibition is bypassed by dithiothreitol (DTT) with an efficiency declining with time, while thiosalicylic acid (TA), an analog of TMS devoid of the mercury atom, has no effect on meiosis reinitiation. These results strongly suggest that the inhibitory effect of TMS is a consequence of its sulfhydryl group oxidising activity. The molecular target(s) of this inhibitory oxidation should however be identified. In contrast to DTT, okadaic acid (OA), known to bypass the inhibitory effect of drugs interfering with protein kinase activities, only induces chromatin condensation and GVBD in TMS-pulsed oocytes with a delay of about 8 hr as compared to the control situation. This confirms that a very early thiol oxidation induced by TMS exerts a much more dramatic effect on resumption on meiosis than any pharmacological manipulation of protein kinase activities leading to activation of MPF.

Thiomersal enhances the binding of histamine to the H1 receptor, but not histamine-stimulated inositol phosphate formation

Thiomersal (thimerosal) was a weak inhibitor of the binding of [(3)H]mepyramine to histamine H(1) receptors in guinea-pig cerebellar membranes (11 +/- 1% inhibition at 10 microM, 32 +/- 3% inhibition at 300 microM). However, in the concentration range 3-30 microM, thiomersal enhanced the binding of histamine to the H(1) receptor, as reflected by the displacement of curves of histamine inhibition of [(3)H]mepyramine binding to lower concentrations, without any change in the Hill coefficient. The ratio of the IC50 values (the concentration giving 50% inhibition) in the absence and presence of thiomersal increased from 1.8 with 3 microM to 3.6 with 30 microM thiomersal. There was no consistent effect of thiomersal at concentrations of 30 microM and below on curves of mepyramine inhibition of [(3)H]mepyramine binding. In the presence of 10 microM thiomersal histamine-induced accumulation of inositol phosphates in U373 MG astrocytoma cells was partially inhibited (37 +/- 8% inhibition of the maximum response), without any significant change in the EC50 (the concentration giving the half maximal response) for histamine. Thus although histamine binding was potentiated by thiomersal, there was no potentiation of an H(1) receptor-mediated functional response.

Allergic contact dermatitis from mercury antiseptics and derivatives: study protocol of tolerance to intramuscular injections of thimerosal

BACKGROUND

Mercury derivatives are frequent contact allergens and their cross-reactivity is not constant. Thimerosal is an organic mercurial used as an antiseptic and as a preservative in most vaccines.

OBJECTIVE

To evaluate cross-reactivity, exposure factors, and tolerance to vaccines containing thimerosal in patients sensitized to mercury derivatives.

METHODS

DESIGN

Observational study (cross-sectional);

PATIENTS

125 patients were recruited for the study, 72 women and girls and 53 boys and men, average age 18.7 years old, range 3 to 65, with positive patch tests to mercury derivatives and/or thimerosal;

INTERVENTIONS

All patients were studied by means of enquiry, patch tests, intradermal tests, and intramuscular challenge with thimerosal.

RESULTS

A sensitization to thimerosal was observed in 57 patients. Twenty-four of these 125 patients presented a positive intradermal reaction. Ammoniated mercury seems to be a good marker of mercury sensitization eliciting positive reaction in 78% of all patients and merbromin in 66%. In most cases, (100/125) cross-reactivity was found among mercury derivatives. The intramuscular injection of thimerosal induced a mild local reaction in only 5 patients (4% of the total, 9% of thimerosal positive reactions). Childhood vaccinations, merbromin used as an antiseptic, broken thermometers, and the use of drops were the main sources of exposure.

CONCLUSIONS

The majority of the patients showed positive tests to both organic and inorganic mercury derivatives. Vaccination with thimerosal is relatively safe, even for individuals with delayed type hypersensitivity to this chemical, since more than 90% of allergic patients tolerated intramuscular challenge tests with thimerosal. A simplified protocol of patch tests to study mercury derivatives is proposed. It would be advisable to restrict the use of mercurial antiseptics and mercury thermometers.

Iatrogenic exposure to mercury after hepatitis B vaccination in preterm infants

Thimerosal, a derivative of mercury, is used as a preservative in hepatitis B vaccines. We measured total mercury levels before and after the administration of this vaccine in 15 preterm and 5 term infants. Comparison of pre- and post-vaccination mercury levels showed a significant increase in both preterm and term infants after vaccination. Additionally, post-vaccination mercury levels were significantly higher in preterm infants as compared with term infants. Because mercury is known to be a potential neurotoxin to infants, further study of its pharmacodynamics is warranted.

Preserved solid lipid nanoparticles (SLN) at low concentrations do cause neither direct nor indirect cytotoxic effects in peritoneal macrophages

In order to investigate the interaction of preserved solid lipid nanoparticles (SLN) with murine peritoneal macrophages (Mpsi), cytotoxicity and proinflammatory effects of two different solid lipid nanoparticles (SLN) preparations consisting of either compritol (CO) or cetyl palmitate (CP) preserved with thiomersal were analyzed. Concentration-dependent cytotoxic effects were observed using the 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay. Secretion of interleukin-6 by Mpsi following incubation with CO and CP SLN did not differ from secretion by untreated cells; proinflammatory cytokines interleukin-12 and tumor-necrosis-factor-alpha as further indicators of immunomodulatory effects were not detectable. These findings paralleled our previous findings that unpreserved CO and CP SLN did not induce immunomodulatory effects but cytotoxicity at higher concentrations. There were no synergistic cytotoxic effects of preservative and SLN. Thus, preservation of SLN using thiomersal does not appear to cause increased cytotoxicity and immunomodulatory effects following incubation with Mpsi.

Preservative-free influenza vaccine

OBJECTIVE

To investigate the immunogenicity of and tolerance towards the preservative-free inactivated influenza vaccine Begrivac.

METHODS

In this prospective, single-centre, non-controlled study, efficacy was evaluated by the change in influenza antibody titre from baseline to 21 days following vaccination. The safety variables included post-injection reactions and adverse events. Blood samples were taken on day 21 and the antibody titre assayed by haemagglutination inhibition test.

RESULTS

All three of the European efficacy requirements for influenza vaccines are satisfied by the new preservative-free vaccine described in this report. The mean geometric increase in titre and the proportion of vaccination responders were greater in patients of the adult group than in the elderly. Thus for strain A/Beijing/262/95 66% of subjects seroconverted and 28% showed a significant increase in antibody titre (total 94%), compared to a total of 45 patients (76%) in the elderly group. For strain A/Sydney/5/97 the corresponding figures were total 55 (90%) adult and 47 (80%) elderly, and for B/Beijing/184/93 46 (75%) adult and 31 (53%) elderly. Sixty four subjects (53%) reported adverse events, mainly local reactions at the injection site such as pain, erythema and induration, and systemic reactions such as headache and fatigue.

CONCLUSIONS

The absence of preservative in this novel vaccine preparation does not have any detectable impact on its efficacy or safety and tolerability profile.

Thimerosal-induced Ca2+ mobilization in isolated guinea pig cochlear outer hair cells

Intracellular calcium mobilization of isolated guinea pig cochlear outer hair cells (OHCs) was investigated using thimerosal, a -SH group oxidizing agent, and fura-2 fluorescence ratio imaging microscopy. In the presence of thimerosal, intracellular Ca2+ concentrations ([Ca2+]i) of OHCs were elevated in a dose-dependent manner. Even in Ca(2+)-free medium, Ca2+ response was still induced. The effects of thimerosal on [Ca2+]i were completely blocked and reversed by dithiothreiotol (DTT). Neither 1-100 microM ryanodine nor 5-20 mM caffeine altered the effects of thimerosal. Pretreatment with pertussis toxin (PTX) for 30 min did not affect the thimerosal-induced increase in [Ca2+]i. The increase in [Ca2+]i when Ca2+ was added during thimerosal application in Ca(2+)-free medium was almost completely blocked by 500 microM LaCl3, while nifedipine did not inhibit further increase in [Ca2+]i caused by thimerosal. Thus, oxidation of the -SH group of the OHC membrane can induce a Ca2+ release from intracellular Ca2+ stores, which are ryanodine- and caffeine-insensitive, and Ca2+ influx through non-specific Ca2+ channels, but not the nifedipine-sensitive Ca2+ channels. The possible oxidation of -SH group gated Ca2+ channels in OHCs is worthy of further study.

Thimerosal positivities: the role of organomercury alkyl compounds

Contact allergy to thimerosal (TH) has not been considered a marker for mercury allergy, since there is a low degree of cross-sensitivity to inorganic as well as to organic mercury salts. 40 subjects, who previously gave a positive patch test reaction only to thimerosal 0.1% pet. (Hermal), when simultaneously repatch-tested to solutions containing TH, mersalyl acid, p-amino-phenylmercuric acid, mercuric acetate and thiosalicylic acid, respectively, gave positive reactions only to TH. 36 out of 40 subjects were divided into 2 groups of 18 subjects and simultaneously repatch-tested to solutions containing TH, methylmercury chloride (MeHgCl), thiosalicylic acid, and, ethylmercury chloride (EtHgCl), respectively. EtHgCl was tested in the 1st group at 0.031% and in the 2nd group at 0.015%. The results showed that all subjects gave concomitant positive reactions to TH, EtHgCl and MeHgCl. EtHgCl 0.031% gave a higher number of reactions than EtHgCl 0.015%, underlining the rôle of the solvent in these reactions. Patch test results in 300 consecutive patients to a standard series, to which MeHgCl was added, showed that MeHgCl and TH were never able to give isolated positive reactions, and that the concomitant positive reactions occurred in only 3.6% of subjects. In conclusion, our data seem to suggest that the positive reactions to TH found in our patients were due to EtHgCl, and that the structural similarities with MeHgCl were so close that the skin reacted against each as if they were identical.

Clinical course of severe poisoning with thiomersal

CASE REPORT

A 44-year-old man ingested 83 mg/kg Thiomersal. He developed gastritis, renal tubular failure, dermatitis, gingivitis, delirium, coma, polyneuropathy and respiratory failure. Treatment was symptomatic plus gastric lavage and the oral chelating agents dimercaptopropane sulfonate and dimercaptosuccinic acid. The patient recovered completely. Maximum mercury concentrations were blood 14 mg/L, serum 1.7 mg/L, urine 10.7 mg/L, and cerebrospinal fluid 0.025 mg/L. Mercury concentration in blood declined with two velocities: first with half-time 2.2 days, then with half-time 40.5 days. The decline of mercury concentration in blood, urinary mercury excretion, and renal mercury clearance were not substantially influenced by chelation therapy.

[Otomycosis and topical application of thimerosal: study of 152 cases]

PURPOSE

To evaluate the effectiveness of the topical application of Timerosal (merthilate tintura) in mycosis involving the external auditory canal.

PATIENTS AND METHODS

The study includes 152 patients with the clinical, otoscopic and microscopic diagnosis of otomycosis. Results were assessed 72 hours and 10 days after the application.

RESULTS

Bacteriological study was performed in 83 patients, finding Aspergilly niger in 54.0% of the cases, Candida albicans in 25.4%, Aspergillus fumigatus in 15.8% and Penicillium in 4.8%. Improvement at 72 h. was found in 66.4% and at 10 days in 93.4% of the patients. Bacteriological contamination was found in 6.6% of the total.

COMMENTS

In most of the patients, the otomycosis healed after cleaning of the external auditory canal and topical application of timerosal. This method is easy to apply, fast, effective, of low cost and few side effects.

Minimum eliciting patch test concentration of thimerosal

Positive patch test reactions to thimerosal 0.1% pet. (40/690 subjects: 5.8%) were more common in younger age groups, in the allergic contact dermatitis group and in subjects who had used contact lens solutions. In the 40 thimerosal-positive patients, the minimum eliciting quantity of preservative was evaluated using different test concentrations: 0.05% and 0.01% pet. (patch testing) and 1:10,000 in saline (intradermal testing). Cross-reactions between thimerosal and other mercury compounds and sensitivity to thiosalicylic acid were also examined. The results of the investigation demonstrate that many of the reactions to 0.1% thimerosal are probably irritant, because only half the subjects studied had positive patch tests when allergen concentrations 5 to 10x lower than that conventionally used for patch testing, were utilized. In these subjects, the average strength of patch test reactions was higher, intradermal testing was more often positive and cross-reactions between mercurials more frequent. These data indicate that the optimal eliciting patch test concentration for studying thimerosal sensitivity is 0.05% pet.

Effect of thimerosal concentration on the efficacy of inactivated Newcastle disease oil-emulsion vaccines

Different quantities of the preservative thimerosal in inactivated Newcastle disease oil-emulsion vaccines were tested to determine the influence on the hemagglutination-inhibition (HI) response of broilers. The effect of thimerosal was measured in vaccines that had been stored for 1, 21, and 52 weeks; HI serology was conducted at 2, 4, and 6 weeks after vaccination. Mean HI titers 4 weeks after vaccination decreased at a significant rate (P less than or equal to 0.001) with increasing concentrations of thimerosal. HI titers 4 weeks after vaccination with 1-week-old vaccine were significantly (P less than or equal to 0.05) higher than those after vaccination with 52-week-old vaccine at all thimerosal concentrations tested. Titers were also significantly higher (P less than or equal to 0.05) after vaccination with 1-week-old vaccine than after vaccination with 21-week-old vaccine at all thimerosal concentrations below about 8.25 mg/ml of antigen. Thimerosal at the levels recommended in commercial vaccines does not significantly decrease vaccine efficacy.