Heparin-induced thrombocytopenia with thrombosis in COVID-19 adult respiratory distress syndrome.

Early reports of coronavirus disease 2019 (COVID-19) clinical features describe a hypercoagulable state, and recent guidelines recommend prophylactic anticoagulation for patients with COVID-19 with low-molecular-weight heparin, but this would be contraindicated in the presence of heparin-induced thrombocytopenia (HIT). We address the key clinical question whether HIT is also present during COVID-19. We report 3 cases of thrombocytopenia with antiplatelet factor 4 antibodies among 16 intubated patients with COVID-19 with adult respiratory distress syndrome, a higher-than-expected incidence of 19%. Each patient had evidence of thrombosis (pulmonary embolism, upper extremity venous thromboses, and skin necrosis, respectively). The serotonin release assay confirmed HIT in 1 case, and 2 cases were negative. We believe this is the first reported case of HIT during the COVID-19 pandemic. Recognition that the thrombocytopenia represented HIT in the confirmed case was delayed. We recommend clinicians monitor platelet counts closely during heparin therapy, with a low threshold to evaluate for HIT.

Evaluation of Protamine as a Disinfectant for Contact Lenses.

PURPOSE: To investigate the ability of protamine, alone or in combination with other antimicrobial agents, to kill bacteria and fungi associated with contact lens-related keratitis. METHODS: The International Organization for Standardization 14729:2001 procedure was used to test the antimicrobial activity of solutions of protamine (23-228 µM) with and without polyhexamethylene biguanide (PHMB) and ethylenediamine tetra-acetic acid (EDTA). The recommended ISO panel of microbes along with six clinical isolates was tested. The effect of increasing sodium chloride concentration on the antimicrobial activity was also assessed. The cytotoxicity of the final protamine/EDTA/PHMB solution was measured using ISO 10993-5 standard assays. RESULTS: Protamine gave a dose-dependent antimicrobial effect, with the highest effect for most strains being at 228 µM (≥6 log reductions of viable bacteria and ≥1 log reduction of viable fungi). Addition of EDTA and PHMB increased the antimicrobial effect for all strains except Pseudomonas aeruginosa ATCC6538, which had optimum activity (≥6 log inhibition) even in protamine alone. The optimum antimicrobial activity of all microbes was achieved in 0.2% sodium chloride, but even in 0.8% sodium chloride, the activity met or exceeded the ISO standard (>3 log reductions for bacteria and >1 log reduction for fungi). None of the formulations was cytotoxic to mammalian cells. CONCLUSIONS: This study highlights the potential for protamine to be used for the development of effective multipurpose disinfection solutions. Further investigations such as stability, compatibility with contact lenses, and in vivo toxicity are warranted.

Effect of Salicylic Acid on the Membrane Proteome and Virulence of Pseudomonas aeruginosa.

PURPOSE: This study aimed to determine the effect of salicylic acid on the membrane proteome, sensitivity to antibiotics, and production of microbial keratitis by Pseudomonas aeruginosa. METHODS: P. aeruginosa 6294 was grown in the presence or absence of 30 mM salicylic acid. Bacterial membrane proteins were extracted in carbonate buffer, separated using two-dimensional gel electrophoresis and identified by mass spectrometry. The minimum inhibitory concentration (MIC) of various antibiotics was determined using P. aeruginosa 6294 grown in presence or absence of salicylic acid. The scratch mouse model of microbial keratitis was used to determine whether treatment with 30 mM salicylic acid could improve the outcome of infection. RESULTS: Growth in salicylic acid altered the membrane proteome of P. aeruginosa 6294. Eighteen proteins, including OprF, OprD, MexA, OprG, PilQ, and flagellin-type A protein, were downregulated, six proteins, including OprM and OprB, were upregulated, and nine proteins were unaffected by growth in salicylic acid. Growth in salicylic acid slightly increased the resistance to carbapenem antibiotics but did not affect MICs of the other antibiotics tested. Salicylic acid treatment significantly reduced the clinical score of eyes and bacterial load in eyes during microbial keratitis but had no effect on numbers of infiltrating neutrophils. CONCLUSION: Salicylic acid altered the membrane proteins of P. aeruginosa, slightly increased the resistance of the bacterium to carbapenem antibiotics only, and was able to reduce the pathogenicity associated with P. aeruginosa infection of mouse corneas. Salicylic acid may be useful as an antimicrobial agent in the treatment of Pseudomonas keratitis.

Protamine as a potential amoebicidal agent for contact lens disinfection.

PURPOSE: To evaluate the amoebicidal efficacy of protamine with polyhexamethylene biguanide (PHMB) and ethylenediamine tetraacetic acid (EDTA). METHODS: The International Organization for Standardization 14729:2001 procedure was modified to test amoebicidal activity. Acanthamoeba cells were inoculated into dilutions of protamine alone (57 to 228 µM) or in combination with PHMB/EDTA and incubated at 25°C for 6 hours. The number of survivors was determined after 7 days of incubation at 32°C on Escherichia coli-seeded agar plates. For encystment, Acanthamoeba trophozoites were incubated in protamine/PHMB/EDTA for 24 hours, and then the number of cysts was counted using a hemocytometer. RESULTS: Protamine showed significant (p < 0.01) activity against trophozoites of both Acanthamoeba strains, which reached 2 log reductions or more for 228 µM compared with that in phosphate buffered saline. The addition of PHMB to protamine significantly (p = 0.002) improved anti-Acanthamoeba effect (0.8 logs reduction) of Acanthamoeba castellanii only. The addition of EDTA to protamine/PHMB only slightly improved efficacy (0.1 logs). Protamine at 228 µM significantly (p < 0.0001) killed the cysts of either strain by between 0.6 and 0.9 logs. Protamine/PHMB significantly increased killing (p = 0.014) of cysts of A. castellanii only. Protamine/PHMB/EDTA did not show synergy against Acanthamoeba cysts. Protamine or protamine/PHMB with or without EDTA did not cause encystment. CONCLUSIONS: Protamine shows good activity against Acanthamoeba trophozoites and cysts and works more effectively in combination with PHMB against A. castellanii. Protamine may be a promising ingredient in contact lens-disinfecting solutions to control Acanthamoeba growth.

Importance of rub and rinse in use of multipurpose contact lens solution.

PURPOSE: The introduction of contact lens multipurpose disinfection solution (MPDS) that can be used in conjunction with a "no-rub" regimen has simplified lens care requirements. Once adhered to a surface, microorganisms can become less susceptible to disinfection. The aim of the study was to evaluate the effect of various regimen steps on the efficacy of MPDS when used with silicone hydrogel and conventional lenses. METHODS: Commercially available MPDSs containing polyquad or polyhexamethylene biguanide were used in conjunction with two types of silicone hydrogel (lotrafilcon B and galyfilcon A) and one type of conventional soft contact lenses (etafilcon A). Challenge microorganisms included Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 9027, Serratia marcescens ATCC 13880, Fusarium solani ATCC 36031, Candida albicans ATCC 10231, or Acanthamoeba polyphaga Ros. The effect of regimen steps "rub and rinse," "rinse-only," or "no rub and no rinse" on the disinfection efficacy of test MPDSs was examined using the ISO 14729 Regimen Test procedure. RESULTS: Overall, the greatest efficacy of MPDSs was observed when "rub and rinse" was performed before disinfection with each of the microorganisms tested, regardless of lens type. "No rub and no rinse" steps resulted in a greater load of microorganisms remaining on lenses compared with the other regimens (p < 0.05). When "rinse-only" was performed before disinfection, the MPDS containing polyquad performed generally better (p < 0.05) than MPDSs containing polyhexamethylene biguanide against bacteria. Significantly, less microorganisms were recovered from galyfilcon A than from other lenses (p < 0.05) when MPDSs were used with "rinse-only" step. CONCLUSIONS: This study has demonstrated that "rub and rinse" is the most effective regimen and should be recommended in conjunction with all multipurpose lens care solutions and all contact lens types, particularly with silicone hydrogel lenses.

Successful outcomes following living donor liver transplantation for portopulmonary hypertension.

Pulmonary arterial hypertension (PAH) associated with portal hypertension [portopulmonary hypertension (PPHTN)] occurs in 2% to 10% of patients with advanced liver disease and carries a very poor prognosis without treatment. Most hepatic transplantation centers consider moderate to severe PPHTN to be a contraindication to liver transplantation because of the high rate of perioperative complications. We present 3 patients with PPHTN who were managed with intravenous prostacyclin therapy followed by living donor liver transplantation (LDLT). These individuals demonstrated subsequent resolution of their pulmonary hypertension and were weaned off all PAH-specific medical therapy. We present their demographics, clinical courses, and hemodynamics. We discuss the potential indications for LDLT and risks with respect to this patient population. Limitations of the Model for End-Stage Liver Disease scoring system and outcome data for this patient population are reviewed. Future studies should be directed toward better defining indications for LDLT in patients with PPHTN, improving medicosurgical management, and assessing long-term outcomes.

Piperacillin-induced immune hemolytic anemia in an adult with cystic fibrosis.

We report a case of drug-induced immune hemolytic anemia (DIIHA) in an adult female with cystic fibrosis (CF), complicating routine treatment of a pulmonary exacerbation with intravenous piperacillin-tazobactam. Workup revealed a positive direct antiglobulin test (DAT) due to red blood cell (RBC)-bound IgG and C3 and piperacillin antibodies detectable in the patient's serum. The potential influence of CF transmembrane conductance regulator mutations on the severity of DIIHA is discussed. This report illustrates the importance of early identification of DIIHA, a rare complication of a commonly utilized medication in CF.

Topical isoflavonoids reduce experimental cutaneous inflammation in mice.

The antioxidant and anti-proliferative biological effects of isoflavonoids are relevant properties to counteract the characteristics of many cutaneous diseases. This study uses ultraviolet (UV)B irradiation to induce inflammation in the mouse skin, as a model for some symptoms of cutaneous inflammatory and hyperproliferative diseases such as psoriasis in humans, with the objective of testing two topically applied isoflavonoid compounds for therapeutic properties. UVB exposure resulted in the overexpression of the cytokines, tumour necrosis factor (TNF)-α, interleukin (IL)-6 and the adhesion molecule P-cadherin. Infiltration into the dermal compartment of mast cell populations was also induced. These factors are also overexpressed in psoriatic skin. The effect of topical applications of two isoflavonoids, equol and a synthetic analogue NV-38, was tested. Both isoflavonoids dose dependently inhibited the UVB induction of cutaneous TNF-α mRNA and protein, a cytokine critical for the initiation of psoriatic inflammation. Expression of IL-6 mRNA and protein was also decreased, and the number of infiltrating mast cells into the dermis was reduced by both isoflavonoids. Furthermore, the upregulated mRNA and protein levels of P-cadherin, a marker characteristic of cutaneous hyperproliferation, were also normalized by both isoflavonoids. These results suggest that this class of compounds has the potential for useful, innocuous anti-inflammatory therapy from topical application in human cutaneous diseases.

Broad spectrum of antibacterial activity of a new multipurpose disinfecting solution.

PURPOSE: Contact lens-related corneal infection and inflammation have been associated with microbial contamination of the contact lens or contact lens storage case. Antimicrobial performance of contact lens disinfection systems is an important factor in reducing contamination. The purpose of this study was to evaluate the antimicrobial efficacy of a new multipurpose disinfecting solution (MPDS), preserved with 0.001% polyquaternium-1 and 0.0005% myristamidopropyl dimethylamine, against a range of bacteria and fungi. METHODS: The MPDS was challenged with a broad range of clinical and environmental isolates, including 10 gram-positive and eight gram-negative bacterial strains and three strains of fungi. The panel of reference microorganisms recommended by the International Organization for Standardization standards was also included. Samples were removed for analysis after 4 hours, 6 hours, or 24 hours of exposure to the MPDS. The number of survivors was determined by plate counts. RESULTS: The new MPDS showed antimicrobial activity against the five reference microorganisms in excess of that recommended by International Organization for Standardization standards. The solution showed a broad spectrum of antibacterial activity, showing more than a 3 log reduction (mean, 4.2 +/- 1.4) in 8 of 10 gram-positive bacteria and more than a 4 log reduction (mean, 5.3 +/- 0.5) in all eight gram-negative bacteria at the 6-hour disinfection time. The efficacy of the solution was increased with longer exposure times (P<0.01). Some differences in activity between clinical and the reference bacterial strains were observed. The solution exceeded the 1 log unit reduction for all fungal species tested. CONCLUSIONS: The new MPDS produced a significant reduction in the growth of various clinical and environmental bacteria and fungi.

Salicylic acid reduces the production of several potential virulence factors of Pseudomonas aeruginosa associated with microbial keratitis.

PURPOSE: Pseudomonas aeruginosa is a common cause of contact-lens-related microbial keratitis. This bacterium is becoming increasingly resistant to antibiotics, and even if the infection can be treated with antibiotics, damage to the cornea resulting from the combined effect of bacteria and host factors can lead to loss of vision. The purpose of this study was to test the effect of salicylic acid on the production of potential virulence factors during the growth of P. aeruginosa. METHODS: Bacterial cells were grown in a subinhibitory concentration of salicylic acid, and supernatants were collected and analyzed for presence of proteases by using zymography and hydrolysis of chromogenic substrates. The supernatants were also analyzed for the amount of acetylated homoserine lactones by using bacterial reporter strains. Pseudomonas cells from salicylic acid cultures were analyzed for their twitching and swimming motility as well as their ability to invade or cause the death of corneal epithelial cells. RESULTS: Growth in a subinhibitory concentration of salicylic acid resulted in a significant reduction in the number of bacterial cells and a reduction in the rate of the number of bacteria increasing during logarithmic growth, but the time to reach the stationary phase of growth was unchanged. These changes in growth pattern affected the amount of acylated homoserine lactones produced by P. aeruginosa 6294. Also affected by growth in salicylic acid was the ability of strain 6294 to show twitching or swimming motility. Salicylic acid also reduced the invasion of strain 6294 into corneal epithelial cells and the epithelial cell death caused by strain 6206. Furthermore, production of proteases by P. aeruginosa was significantly reduced by growth in salicylic acid. CONCLUSIONS: The results of this study clearly demonstrate that salicylic acid has a significant impact on several potential virulence factors of P. aeruginosa that may be involved in the production of microbial keratitis. These effects were probably mediated by reduction in the cell density and concomitant reduction in the quorum-sensing signaling molecules, the acylated homoserine lactones, produced by P. aeruginosa.