Ebola virus persistence and disease recrudescence in the brains of antibody-treated nonhuman primate survivors.

Effective therapeutics have been developed against acute Ebola virus disease (EVD) in both humans and experimentally infected nonhuman primates. However, the risk of viral persistence and associated disease recrudescence in survivors receiving these therapeutics remains unclear. In contrast to rhesus macaques that survived Ebola virus (EBOV) exposure in the absence of treatment, we discovered that EBOV, despite being cleared from all other organs, persisted in the brain ventricular system of rhesus macaque survivors that had received monoclonal antibody (mAb) treatment. In mAb-treated macaque survivors, EBOV persisted in macrophages infiltrating the brain ventricular system, including the choroid plexuses. This macrophage infiltration was accompanied by severe tissue damage, including ventriculitis, choroid plexitis, and meningoencephalitis. Specifically, choroid plexus endothelium-derived EBOV infection led to viral persistence in the macaque brain ventricular system. This resulted in apoptosis of ependymal cells, which constitute the blood-cerebrospinal fluid barrier of the choroid plexuses. Fatal brain-confined recrudescence of EBOV infection manifested as severe inflammation, local pathology, and widespread infection of the ventricular system and adjacent neuropil in some of the mAb-treated macaque survivors. This study highlights organ-specific EBOV persistence and fatal recrudescent disease in rhesus macaque survivors after therapeutic treatment and has implications for the long-term follow-up of human survivors of EVD.

Liposomal Bupivacaine Suspension for Pain Control Following Ocular Evisceration Surgery.

PURPOSE: To determine the effectiveness of retrobulbar liposomal bupivacaine for controlling postoperative pain following evisceration, compared with 0.75% bupivacaine. METHODS: Randomized controlled trial, in which the postoperative pain scores from 24 patients who had retrobulbar liposomal bupivacaine after an evisceration were compared with the pain scores from 24 patients eviscerated using 0.75% bupivacaine. RESULTS: Patients who received liposomal bupivacaine reported significantly less pain at 24 hours (2.0 out of 10, p = 0.01) and 48 hours (2.2 out of 10, p = 0.01) after surgery than patients who received 0.75% bupivacaine (5.7, and 5.0, respectively). The postoperative pain scores at 1 hour and at 7 days did not significantly differ between the 2 groups. Significantly, fewer patients who received liposomal bupivacaine (0%) than patients who received 0.75% bupivacaine (16.7%) returned emergently during the postoperative period for uncontrolled pain (p ≤ 0.001). CONCLUSIONS: Retrobulbar liposomal bupivacaine is more effective than 0.75% bupivacaine for controlling pain during the first 2 days after evisceration and should be considered for patients undergoing this procedure.

Development of a coronavirus disease 2019 nonhuman primate model using airborne exposure.

Airborne transmission is predicted to be a prevalent route of human exposure with SARS-CoV-2. Aside from African green monkeys, nonhuman primate models that replicate airborne transmission of SARS-CoV-2 have not been investigated. A comparative evaluation of COVID-19 in African green monkeys, rhesus macaques, and cynomolgus macaques following airborne exposure to SARS-CoV-2 was performed to determine critical disease parameters associated with disease progression, and establish correlations between primate and human COVID-19. Respiratory abnormalities and viral shedding were noted for all animals, indicating successful infection. Cynomolgus macaques developed fever, and thrombocytopenia was measured for African green monkeys and rhesus macaques. Type II pneumocyte hyperplasia and alveolar fibrosis were more frequently observed in lung tissue from cynomolgus macaques and African green monkeys. The data indicate that, in addition to African green monkeys, macaques can be successfully infected by airborne SARS-CoV-2, providing viable macaque natural transmission models for medical countermeasure evaluation.

Biological variation of thromboelastrography variables in 10 clinically healthy horses.

OBJECTIVE: To assess the utility of population-based reference intervals (PRIs) for interpreting thromboelastography (TEG) variables in horses using biological variation data. DESIGN: Prospective cohort biologic variation study conducted over a 5-week period. SETTING: Veterinary teaching hospital and research facility. ANIMALS: Ten clinically healthy horses randomly selected from a veterinary school research and teaching herd. INTERVENTIONS: Horse health was determined using physical examination, CBC, and biochemical and coagulation profiles prior to the start of the study. Subsequently, once weekly blood sampling for TEG testing was performed for 5 weeks. MEASUREMENTS AND MAIN RESULTS: The 4 TEG variables reaction time (R), clot formation time (K), angle, and maximum amplitude (MA) were measured, and coefficient of variation representing within- and between-horse biological variation (CVi and CVg , respectively) and coefficient of variation representing analytical variation (CVa ) were calculated using a nested ANOVA after removing outlier data. The CVi , CVg , and CVa for R were 26.8%, 5.2%, and 5.9%; for K were 31.0%, 0.0%, and 5.9%; for angle were 9.4%, 6.2%, and 21.7%; and for MA were 3.4%, 4.1%, and 4.4%, respectively. Index of individuality (IOI) was then calculated for each variable using the formula {( CVi² + CVa²/CVg²)}¹/². IOI for R was 5.3, for angle was 3.8, and for MA was 1.4; IOI was not assessed for K. CONCLUSIONS: PRIs are appropriate for TEG variables, R, angle, and MA when interpreting results from individual horses based on calculated IOI values equal to or greater than 1.4. PRIs are likely appropriate when interpreting K, but IOI could not be calculated for this variable.

Hypercalcemia and parathyroid hormone-related peptide expression in a dog with thyroid carcinoma and histiocytic sarcoma.

A 9.5-year-old, male castrated Walker Hound was presented for evaluation of progressive weakness, anorexia, and weight loss. Imaging revealed multiple abdominal and thoracic masses and ascites; fine-needle aspirates of mesenteric and splenic masses confirmed malignancy, most likely histiocytic sarcoma. Laboratory analyses revealed increased ionized calcium and parathyroid hormone-related peptide (PTH-rP) concentrations, and concurrent low-normal parathyroid hormone concentration, consistent with humoral hypercalcemia of malignancy. Necropsy was performed after euthanasia. The dog had disseminated histiocytic sarcoma, including sarcomatosis, as well as bilateral thyroid carcinoma. PTH-rP immunostaining was positive in the thyroid carcinoma but negative in the histiocytic neoplasm. These results suggest that thyroid carcinoma-associated hypercalcemia can be caused by tumor secretion of PTH-rP.

Use of Noncadaveric Human Acellular Dermal Tissue (BellaDerm) in Lower Eyelid Retraction Repair.

PURPOSE: To evaluate the efficacy and longevity of a human-derived, noncadaveric, acellular dermal implant (BellaDerm) as a posterior spacer graft in the correction of lower eyelid retraction, taking into consideration issues associated with the use of acellular dermis such as contraction and potential regression of repairs. METHODS: A prospective, nonrandomized clinical study involving the use of BellaDerm as a posterior spacer graft to correct symptomatic lower eyelid retraction secondary to involutional, cicatricial, and paralytic etiologies. Pre- and postoperative margin reflex distance 2 and inferior scleral show (ISS) were measured for each eyelid, and success was defined as a positive eyelid elevation and decrease in ISS. Long-term stability beyond 12 months was evaluated. Resolution of symptoms and postoperative complications were also documented. RESULTS: Fifteen eyelids of 11 patients were included. All eyes showed an improvement in eyelid elevation and decrease in ISS, both of which were statistically significant. The mean improvement in margin reflex distance 2 for all eyelids was 2.2 mm (p<0.0001). The mean decrease in ISS for all eyelids was 1.7 mm (p<0.0001). The average duration of follow up was 15.6 months. Ten eyelids of seven patients had greater than 12 months of follow up (mean 21.9 months), and this subset was evaluated separately to emphasize longevity of results. In this subset, the mean improvement in margin reflex distance 2 was 2.4 mm (p<0.0001), and the mean decrease in ISS was 1.7 mm (p=0.0003). CONCLUSIONS: Noncadaveric human acellular dermal tissue is efficacious in treating lower eyelid retraction. BellaDerm produced long-term symptomatic relief and stable clinical correction of lower eyelid retraction secondary to multiple etiologies. These findings contradict the thinking that although acellular dermis is an adequate modality for correction of eyelid retraction, results may be compromised by graft resorption and recurrence of symptoms. Improved biological integrity from live donor harvesting or alternate processing techniques may contribute to the success of this particular acellular dermis.

Identification of blue staining vaccine-derived material in inflammatory lesions using cultured canine macrophages.

BACKGROUND: Vaccine reactions are described in cytology textbooks as having eosinophilic to magenta colored globules within and admixed with inflammatory cells. Recently, we have seen increased numbers of inflammatory lesions containing blue to blue-gray globular material, with historical information suggesting an association with rabies vaccination. OBJECTIVES: The purpose of the study was to confirm the blue-gray and the eosinophilic material observed microscopically in some inflammatory lesions as being vaccine-derived. METHODS: Three different vaccines were cytocentrifuged and Wright stained. Vaccine aliquots were also added to the culture media of canine-derived macrophages for 24 hours and the cells subsequently harvested, cytocentrifuged, and Wright stained. The globular material present in both preparations was compared to that observed in vaccine-induced inflammatory lesions. Morin staining was used to identify metal within vaccine material in both in vitro- and in vivo-derived cytology samples. RESULTS: Vaccine-derived material has a characteristic color and appearance. Appearance of the material was consistent in cytologic samples, in cells incubated with the vaccine, and in cytocentrifuged preparations of the vaccine vial contents. The blue-gray globules stained positively for Morin stain, while the eosinophilic material did not stain. CONCLUSIONS: Vaccine-induced inflammatory lesions may contain blue to blue-gray or magenta stained globular material. Blue-gray material was associated with administration of rabies vaccine Imrab 3 TF and the observed material may be metal-containing adjuvant. Magenta material was associated with other vaccines and negative for Morin stain, suggesting a metal-free adjuvant.

Effects of freezing on tissue factor activity in a thromboelastography assay.

BACKGROUND: Human recombinant tissue factor (TF) can be used to activate viscoelastic coagulation assays. Although the package insert indicates that TF should not be frozen, published scientific data are not available. Ability to store frozen aliquots of TF would increase laboratory efficiency and decrease costs associated with performing TF-activated assays. OBJECTIVE: The objectives of this study were to determine the effects of freezing and storage time on TF's ability to activate commercially available quality control material in thromboelastography (TEG). METHODS: TF was diluted and frozen at -20°C and -70°C for 72 hours, one week, 2 weeks, 3 months, and 6 months, and used for TEG after thawing. TF activation of control material was also assessed after TF storage at room temperature for 0, 24, and 48 hours. Time to fibrin formation (R), rate of clot formation (K and angle α), and clot strength (MA) were measured, and ANOVA used to identify differences. RESULTS: There were no significant differences in mean α and MA regardless of storage time or temperature. Means for R were not significantly increased at any time point after storage at room temperature or -70°C, but significant increases in mean R were observed after storage at -20°C starting after one week and continuing up to 6 months. CONCLUSION: TF can be stored at room temperature for at least 48 hours, stored at -20°C for 72 hours, and stored at -70°C for up to 6 months without significant loss of activity for TEG.

Calcium signaling and T-type calcium channels in cancer cell cycling.

Regulation of intracellular calcium is an important signaling mechanism for cell proliferation in both normal and cancerous cells. In normal epithelial cells, free calcium concentration is essential for cells to enter and accomplish the S phase and the M phase of the cell cycle. In contrast, cancerous cells can pass these phases of the cell cycle with much lower cytoplasmic free calcium concentrations, indicating an alternative mechanism has developed for fulfilling the intracellular calcium requirement for an increased rate of DNA synthesis and mitosis of fast replicating cancerous cells. The detailed mechanism underlying the altered calcium loading pathway remains unclear; however, there is a growing body of evidence that suggests the T-type Ca(2+) channel is abnormally expressed in cancerous cells and that blockade of these channels may reduce cell proliferation in addition to inducing apoptosis. Recent studies also show that the expression of T-type Ca(2+) channels in breast cancer cells is proliferation state dependent, i.e. the channels are expressed at higher levels during the fast-replication period, and once the cells are in a non-proliferation state, expression of this channel is minimal. Therefore, selectively blocking calcium entry into cancerous cells may be a valuable approach for preventing tumor growth. Since T-type Ca(2+) channels are not expressed in epithelial cells, selective T-type Ca(2+) channel blockers may be useful in the treatment of certain types of cancers.

Image-guided endoscopic orbital decompression for Graves' orbitopathy.

OBJECTIVES: We studied the efficacy and safety of image-guided balanced orbital decompression for Graves' orbitopathy. METHODS: The data of 24 patients (45 orbits) were reviewed for demographics, ophthalmologic outcomes, and complications in regard to image-guided (18 orbits) versus non-image-guided surgery (27 orbits). RESULTS: Overall, all patients had a reduction in proptosis (mean reduction, 6.2 mm in proptosis) as measured by Hertel exophthalmometry. There was improvement in the visual acuity of all 12 orbits with preoperative acuity of 20/40 or worse and either complete resolution (38%) or improvement (62%) in the 16 orbits with optic neuropathy. These measures reached statistical significance. Despite subjective improvement in surgeon confidence, the use of image guidance did not result in a statistically significant difference in postoperative ophthalmologic outcomes. Medical and sinonasal complications were experienced by 11.1% and 18.5% of patients who underwent image-guided and non-image-guided orbital decompression, respectively. CONCLUSIONS: Image guidance may be a useful adjunct to balanced orbital decompression for Graves' orbitopathy, but it was not associated with a statistically significant improvement in outcomes in this study.

The hallucinogen 1-[2,5-dimethoxy-4-iodophenyl]-2-aminopropane (DOI) increases cortical extracellular glutamate levels in rats.

Activation of the cerebral cortex is seen during hallucinations. The 5-HT(2A/C) agonist 1-[2,5-dimethoxy-4-iodophenyl]-2-aminopropane (DOI) is a potent hallucinogen that has been proposed to act by targeting 5-HT(2A) heteroceptors on thalamocortical neurons and eliciting release of glutamate from these cells, which in turn drives cortical neurons. We used in vivo microdialysis to determine if DOI increases extracellular glutamate levels. Systemic administration of DOI significantly increased extracellular glutamate levels in the somatosensory cortex of the freely-moving rat. Similarly, intracortical administration of DOI by reverse dialysis increased cortical extracellular glutamate levels. No consistent changes in either extracellular GABA or glycine levels were observed in response to DOI. The increase in glutamate levels elicited by intracortical DOI was blocked by treatment with the selective 5-HT(2A) antagonist MDL 100,907. These data are consistent with the hypothesis that 5-HT(2A) receptor-mediated regulation of glutamate release is the mechanism through which hallucinogens activate the cerebral cortex.