Food and Drug Administration Beyond the 2001 Government Accountability Office Report: Promoting Drug Safety for Women

A 2001 U.S. Government Accountability Office (GAO) report indicated 8 of 10 drugs withdrawn from the U.S. market between 1997 and 2000 posed greater risk to women than men. We examined drugs withdrawn from the market for safety-related reasons from January 1, 2001, to January 1, 2018. To be included, drugs must be listed as discontinued on Drugs@FDA and either listed in the Federal Register or cited in literature as being withdrawn for safety-related reasons. Biologics, over-the-counter products, and medical devices were excluded. During the 17-year time span, 19 drugs were withdrawn from the market for safety-related reasons, fewer drugs per year compared to the 3-year period examined in the GAO report. Food and Drug Administration (FDA) has not recommended the market removal of any drug approved since 2005 due to the time from the start of the Q wave to the end of the T wave (QT) interval prolongation resulting in torsades de pointes (TdP) or other abnormal heart rhythms. Furthermore, no drugs approved after the implementation of FDA's 2009 guidance on drug-induced liver injury (DILI) have been withdrawn because of hepatoxicity. All, but one of the drugs discontinued from the market for safety-related reasons during the period examined were approved between 1957 and 2002. TdP and DILI are two relevant examples of drug-induced adverse events posing greater risk to women than men. FDA has made measurable progress incorporating consideration of sex and gender differences into drug trial development and FDA review of these data, supporting inclusion of women in clinical trials, providing a comprehensive drug safety review, and advancing postmarket surveillance and risk assessment, thus strengthening FDA's ability to protect public health.

Molecular diversity of Staphylococcus aureus and the role of milking equipment adherences or biofilm as a source for bulk tank milk contamination

Staphylococcus aureus is one of the most frequent pathogens causing intramammary infections in dairy herds. Consequently, virulence factors, pathobiology, and epidemiology of Staphylococcus aureus strains have been widely assessed through the years. Nevertheless, not much has been described about the epidemiology of Staph. aureus strains from bulk tank milk (BTM) and adherences on milking equipment (AMES), even when these strains may play a role in the quality of milk that is intended for human consumption. The objective of this study was to assess the strain diversity of 166 Staph. aureus isolates collected from 3 consecutive BTM samples, and from AMES in contact with milk from 23 Chilean dairy farms. Isolates were analyzed and typed using pulsed-field gel electrophoresis. Diversity of strains, both within and among farms, was assessed using Simpson's index of diversity (SID). On farms where Staph. aureus was isolated from both AMES and BTM (n = 8), pulsotypes were further analyzed to evaluate the role of AMES as a potential source of Staph. aureus strains in BTM. Among all Staph. aureus analyzed by pulsed-field gel electrophoresis, a total of 42 pulsotypes (19 main pulsotypes and 23 subtypes) were identified. Among dairy farms, strain diversity was highly heterogeneous (SID = 0.99). Within dairy farms, Staph. aureus strain diversity was variable (SID = 0 to 1), and 18 dairy operations (81.8%) had one pulsotype that was shared between at least 2 successive BTM samples. In those farms where Staph. aureus was isolated in both AMES and BTM (n = 8), 7 (87.5%) showed a clonal distribution of Staph. aureus strains between these 2 types of samples. The overlapping of certain Staph. aureus strains among dairy farms may point out common sources of Staph. aureus among otherwise epidemiologically unrelated farms. Indistinguishable Staph. aureus strains between AMES and BTM across dairy farms suggest that Staph. aureus-containing AMES may represent a source for BTM contamination, thus affecting milk quality. Our study highlights the role of viable Staph. aureus in AMES as a source for BTM contamination on dairy farms, and also describes the overlapping and presence of specific BTM and AMES pulsotypes among farms.

Complementary Use of U.S. FDA's Adverse Event Reporting System and Sentinel System to Characterize Direct Oral Anticoagulants-Associated Cutaneous Small Vessel Vasculitis

BACKGROUND

Cutaneous small vessel vasculitis (CSVV) has been reported after exposure to direct oral anticoagulants (DOACs), such as dabigatran, rivaroxaban, apixaban, and edoxaban.

OBJECTIVE

We used the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) to describe clinical characteristics associated with CSVV among DOAC-exposed patients. Furthermore, we characterized this signal in the Sentinel System to relate the clinical data from the individual FAERS cases to population-based electronic healthcare data.

METHODS

We queried FAERS for all cases of CSVV associated with DOACs from U.S. approval date of each DOAC through March 16, 2018. Within the Sentinel System, we identified incident CSVV cases using ICD-9 and ICD-10 diagnosis codes among adults aged ≥ 30 years who received a DOAC in the prior 90 days between January 1, 2010, and June 30, 2018. We excluded patients with evidence of select autoimmune diagnoses in the 183 days prior to their CSVV diagnoses and reported patient characteristics in the 183-day period prior to CSVV diagnoses.

RESULTS

In FAERS, we identified 50 cases of CSVV reported with rivaroxaban (n=26), apixaban (n=14), dabigatran (n=9), and edoxaban (n=1). Approximately 50% of the cases reported time to onset within 10 days after DOAC exposure. When specified, the predominant type of CSVV reported was leukocytoclastic vasculitis (n=31), followed by Henoch-Schonlein purpura (n=4). Hospitalization occurred in most of the cases (n=37). Switching of the offending agent after the development of CSVV was reported (n=26). Three rivaroxaban (n=3) cases and one dabigatran case (n=1) reported positive rechallenge. In the Sentinel system, we identified 3659 CSVV cases with prior DOAC exposure, with 85% of events occurring within 10 days.

CONCLUSIONS

The assessment of FAERS cases, combined with the temporal clustering of the Sentinel System cases suggest a possible causal relationship of DOACs and CSVV. Future efforts should characterize the risk of CSVV among the various DOAC users.

Short communication: Virulence profiles of Staphylococcus aureus isolated from bulk tank milk and adherences on milking equipment on Chilean dairy farms

Staphylococcus aureus is an important intramammary pathogen for dairy cows that also is remarkably important for public health. Multiple virulence factors can be involved simultaneously during the pathogenesis of a staphylococcal disease, including adhesion proteins, extracellular enzymes, and toxins. The main objective of this study was to assess virulence factors that are associated with cow intramammary infection (IMI) and of human health concern among Staph. aureus isolates obtained from bulk tank milk (BTM) and adherences on milking equipment surfaces. A total of 166 Staph. aureus isolates from 23 dairy farms were characterized according to their virulence profiles. For virulence factors of importance in IMI, the presence of the virulence markers thermonuclease (nuc) and coagulase (coa) and virulence genes such as fibronectin (fnbA) and intercellular adhesion (icaA, icaD) were assessed. For virulence factors of public health concern, presence of antimicrobial resistance (mecA and mecC) and enterotoxin (sea and seb) genes were analyzed. Among all Staph. aureus isolates, 5 virulence profiles were found; the profile nuc⁽⁺⁾coa⁽⁺⁾fnbA⁽⁺⁾icaA⁽⁺⁾icaD⁽⁺⁾mecA^(-)mecC^(-)sea^(-)seb^(-) was the most frequently observed (21 out of 23 dairy farms). No differences were found between the virulence profile frequencies of Staph. aureus from BTM and adherences on milking equipment surfaces. The virulence profiles most frequently observed included genes involved in the adherence and biofilm-forming ability of Staph. aureus, which could represent a potential advantage for the bacterium during the early stages of IMI colonization and for persistence on surfaces. Our results indicate a greater frequency of virulence factors of importance for IMI pathogenesis than virulence factors of public health concern, consistent with the dairy origin of isolates. The mecA, mecC, and seb genes were not observed among Staph. aureus isolates analyzed in this study. However, the sea gene was detected in 3 Staph. aureus isolated from BTM, thus posing a potential public health threat. Our results emphasize the importance of understanding the epidemiology and dynamics of Staph. aureus on dairy farms as a tool for the improvement of udder health and milk safety.

Surgical treatment of hindfoot inflammatory diseases: 107 arthrodesis

INTRODUCTION

In rheumatoid diseases, hindfoot arthrodesis abolishes pain and corrects deformity. The choice between selective and double arthrodesis depends on whether the hindfoot malalignment is fixed or not. Indications for surgery are well codified. The various types of arthrodesis have never been assessed together on a large series. We here report a series that is substantial in numbers and in follow-up.

MATERIALS AND METHODS

A continuous single-center retrospective study included patients with native hindfoot inflammatory disease treated by arthrodesis between 1996 and 2009.

RESULTS

Around 80% of patients were followed up, for a mean 7 years. Fifty-four isolated talonavicular arthrodeses, 14 talocalcaneal arthrodeses and 39 double arthrodeses were performed. 96% of patients had rheumatoid arthritis and 4% spondylarthritis. 62% were completely pain-free at follow-up. The satisfaction rate was 91% and mean AOFAS score 70%. 6% of patients showed symptomatic non-union, mainly associated with talonavicular arthrodesis. In 22% of double arthrodeses and 11% of talonavicular arthrodeses, ankle status required surgical revision. In double arthrodesis, there was no correlation between hindfoot deviation and secondary deterioration in ankle status. Talocalcaneal arthrodesis was associated with radiologic hindfoot varus, both preoperatively and at follow-up.

DISCUSSION

Non-union was the main complication in talonavicular arthrodesis. The rate of secondary ankle surgery was significantly elevated in double arthrodesis. These findings support Suckel's cadaver studies, which, in 2007, reported early deterioration in ankle status in double arthrodesis, due to mechanical overloading. Talocalcaneal arthrodesis proved reliable and simple, free of major complications and with a 100% satisfaction rate.

CONCLUSION

Double arthrodesis showed the greatest benefit in terms of restoring foot architecture, but was associated with a higher rate of deterioration in ankle status. Preventive double arthrodesis is not recommended in case of isolated arthritis with reducible hindfoot malalignment.

Sources of Klebsiella and Raoultella species on dairy farms: be careful where you walk

Klebsiella spp. are a common cause of mastitis, milk loss, and culling on dairy farms. Control of Klebsiella mastitis is largely based on prevention of exposure of the udder to the pathogen. To identify critical control points for mastitis prevention, potential Klebsiella sources and transmission cycles in the farm environment were investigated, including oro-fecal transmission, transmission via the indoor environment, and transmission via the outdoor environment. A total of 305 samples was collected from 3 dairy farms in upstate New York in the summer of 2007, and included soil, feed crops, feed, water, rumen content, feces, bedding, and manure from alleyways and holding pens. Klebsiella spp. were detected in 100% of rumen samples, 89% of water samples, and approximately 64% of soil, feces, bedding, alleyway, and holding pen samples. Detection of Klebsiella spp. in feed crops and feed was less common. Genotypic identification of species using rpoB sequence data showed that Klebsiella pneumoniae was the most common species in rumen content, feces, and alleyways, whereas Klebsiella oxytoca, Klebsiella variicola, and Raoultella planticola were the most frequent species among isolates from soil and feed crops. Random amplified polymorphic DNA-based strain typing showed heterogeneity of Klebsiella spp. in rumen content and feces, with a median of 4 strains per 5 isolates. Observational and bacteriological data support the existence of an oro-fecal transmission cycle, which is primarily maintained through direct contact with fecal contamination or through ingestion of contaminated drinking water. Fecal shedding of Klebsiella spp. contributes to pathogen loads in the environment, including bedding, alleyways, and holding pens. Hygiene of alleyways and holding pens is an important component of Klebsiella control on dairy farms.

Short Communication: Patterns of Fecal Shedding of Klebsiella by Dairy Cows

Patterns and persistency of fecal shedding of Klebsiella spp. by healthy adult dairy cattle were explored with probabilistic, statistical, and molecular methods. Fecal shedding was monitored longitudinally in 92 animals in 1 herd for 5 mo. Shedding patterns followed a random binomial distribution, and associations with host factors were not detected. For 12 animals from 4 herds, strain-typing of multiple fecal Klebsiella isolates was performed by means of random-amplified polymorphic DNA typing. For 2 animals, additional typing was performed on isolates from samples collected on several consecutive days. A large variety of Klebsiella strains was detected within samples (on average, 3.1 strains per 4 isolates) and between samples (18 of 20 strains were detected only once in feces from cows that were sampled for 5 d consecutively). Results from each method suggest that fecal shedding of Klebsiella is associated with transient rather than persistent presence of the organism in the gastrointestinal tract.

Fecal Shedding of Klebsiella pneumoniae by Dairy Cows

Klebsiella pneumoniae is a common cause of clinical mastitis in dairy cattle. Wood products are considered to be the main source of Klebsiella on dairy farms. Environmental hygiene and use of inorganic bedding materials such as sand are recommended to control Klebsiella mastitis. However, Klebsiella mastitis still occurs on well-managed dairy farms that use sand as bedding material. In a 5-mo study in a New York State dairy herd performed during the summer of 2005, all of 9 samples of unused sand bedding tested negative for Klebsiella, whereas 14 of 18 samples of used sand bedding contained Klebsiella at a median level of 10(4.6) cfu/g. We hypothesized that fecal shedding of Klebsiella by dairy cows contributes to the presence of Klebsiella in the environment. Using a cheap and simple method based on ampicillin-containing MacConkey agar for screening, and biochemical tests for confirmation of species identity, 595 fecal samples from healthy dairy cattle were screened for presence of Klebsiella. In a longitudinal study of 100 cows followed over 5 mo, more than 80% of fecal samples tested positive for K. pneumoniae. The average prevalence of K. pneumoniae-positive fecal samples was also above 80% in a cross-sectional study of 100 cows from 10 herds across New York and Massachusetts. Fecal shedding of K. pneumoniae by a large proportion of dairy cows may explain why Klebsiella mastitis occurs in herds that use inorganic bedding material or other bedding material that is free from Klebsiella upon introduction into the barn.

Interface scaling in the contact process

A correspondence between lattice models with absorbing states and models of pinned interfaces in random media can be established by defining local height variables h(x,t) as integrals of the activity at point x up to time t. Within this context we study the interface representation of a prototypical model with absorbing states, the contact process, in dimensions 1-3. Simulations confirm the scaling relation beta(W)=1-straight theta between the interface-width growth exponent beta(W) and the exponent straight theta governing the decay of the order parameter. A scaling property of the height distribution, which serves as the basis for this relation, is also verified. The height-height correlation function shows clear signs of anomalous scaling, in accord with Lopez' analysis [Phys. Rev. Lett. 83, 4594 (1999)], but no evidence of multiscaling.

Systems with superabsorbing states

We report on some extensive analyses of a recently proposed model [A. Lipowski, Phys. Rev. E 60, 6255 (1999)] with infinitely many absorbing states. By performing extensive Monte Carlo simulations, we have determined critical exponents and shown strong evidence that this model is not in the directed percolation universality class. The conjecture that this two-dimensional model exhibits a dimensional reduction (behaving as one-dimensional directed percolation) is firmly disproven. The reason for the model not exhibiting standard directed percolation scaling behavior is traced back to the existence of what we call superabsorbing sites, i.e., absorbing sites that cannot be directly activated by the presence of neighboring activity in one or more than one direction. Supporting this claim we present two strong evidences: (i) in one dimension, where superabsorbing sites do not appear at the critical point, the system behaves as directed percolation, and (ii) in a modified two-dimensional variation of the model, defined on a honeycomb lattice, for which superabsorbing sites are very rarely observed, directed percolation behavior is recovered. Finally, a parallel updating version of the model exhibiting a nonequilibrium first-order transition is also reported.

Absorbing-state phase transitions in fixed-energy sandpiles

We study sandpile models as closed systems, with the conserved energy density zeta playing the role of an external parameter. The critical energy density zeta(c) marks a nonequilibrium phase transition between active and absorbing states. Several fixed-energy sandpiles are studied in extensive simulations of stationary and transient properties, as well as the dynamics of roughening in an interface-height representation. Our primary goal is to identify the universality classes of such models, in hopes of assessing the validity of two recently proposed approaches to sandpiles: a phenomenological continuum Langevin description with absorbing states, and a mapping to driven interface dynamics in random media.

Universality classes of driven lattice gases

Motivated by some recent criticisms to our alternative Langevin equation for driven lattice gases (DLG) under an infinitely large driving field, we revisit the derivation of such an equation, and test its validity. As a result, an additional term, coming from a careful consideration of entropic contributions, is added to the equation. This term heals all the recently reported generic infrared singularities. The emerging equation is then identical to that describing randomly driven diffusive systems. This fact confirms our claim that the infinite driving limit is singular, and that the main relevant ingredient determining the critical behavior of the DLG in this limit is the anisotropy and not the presence of a current. Different aspects of our picture are discussed, and it is concluded that it constitutes a very plausible scenario to rationalize the critical behavior of the DLG and variants of it.

Renormalized field theory of driven lattice gases under infinitely fast drive

We use field theoretic renormalization group methods to study the critical behavior of a recently proposed Langevin equation for driven lattice gases under infinitely fast drive. We perform an expansion around the upper critical dimension, d(c)=4, and obtain the critical exponents to one-loop order. The main features of the two-loop calculation are also outlined. The renormalized theory is shown to exhibit a behavior different from the standard field theory for the driven lattice gas with finite driving, i.e., it is not mean-field-like.

EBV-positive non-Hodgkin's lymphoma developing after phenytoin therapy

We report the first case of Epstein Barr virus (EBV) positive non-Hodgkin's lymphoma occurring 20 years after continuous phenytoin therapy for idiopathic epilepsy. This malignant lymphoproliferative disease was preceded by an phenytoin-associated benign reactive lymphadenopathy. Serological findings suggested a chronic active EBV infection. Immunohistochemistry showed that neoplastic cells expressed B antigens (CD20, lambda) and the bcl-2 protein. The presence of EBV-encoded latent membrane protein 1 (LMP 1) was also expressed on neoplastic cells. Cytotoxic chemotherapy (CHOP) reversed the non-Hodgkin's lymphoma.