Validation of the North America expert consensus statement on reporting CT findings for COVID-19 in individuals with lung cancer.

The aim of our study was to validate the use of the standardized Radiological Society of North America (RSNA) reporting system in individuals with known lung cancer who presented to the emergency department with suspected COVID-19. We included patients aged 18 years or older from the Cancer Institute of the State of São Paulo (ICESP) with a confirmed diagnosis of lung cancer, admitted to the emergency department and undergoing chest computed tomography (CT) for suspicion of COVID-19. Comparison between SARS-CoV2 RT-PCR across RSNA categories was performed in all patients and further stratified by diagnosis of lung cancer progression. Among 58 individuals included in the analysis (65±9 years, 43% men), 20 had positive RT-PCR. Less than a half (43%) had no new lung findings in the CT. Positive RT-PCR was present in 75% of those with typical findings according to RSNA and in only 9% when these findings were classified as atypical or negative (P<0.001). Diagnostic accuracy was even higher when stratified by the presence or absence of progressive disease (PD). Extent of pulmonary inflammatory changes was strongly associated with higher mortality, reaching a lethality of 83% in patients with >25% of lung involvement and 100% when there was >50% of lung involvement. The lung involvement score was also highly predictive of prognosis in this population as was reported for non-lung cancer individuals. Collectively, our results demonstrated that diagnostic and prognostic values of chest CT findings in COVID-19 are robust to the presence of lung abnormalities related to lung cancer.

Validation of the North America expert consensus statement on reporting CT findings for COVID-19 in individuals with lung cancer

The aim of our study was to validate the use of the standardized Radiological Society of North America (RSNA) reporting system in individuals with known lung cancer who presented to the emergency department with suspected COVID-19. We included patients aged 18 years or older from the Cancer Institute of the State of São Paulo (ICESP) with a confirmed diagnosis of lung cancer, admitted to the emergency department and undergoing chest computed tomography (CT) for suspicion of COVID-19. Comparison between SARS-CoV2 RT-PCR across RSNA categories was performed in all patients and further stratified by diagnosis of lung cancer progression. Among 58 individuals included in the analysis (65±9 years, 43% men), 20 had positive RT-PCR. Less than a half (43%) had no new lung findings in the CT. Positive RT-PCR was present in 75% of those with typical findings according to RSNA and in only 9% when these findings were classified as atypical or negative (P<0.001). Diagnostic accuracy was even higher when stratified by the presence or absence of progressive disease (PD). Extent of pulmonary inflammatory changes was strongly associated with higher mortality, reaching a lethality of 83% in patients with >25% of lung involvement and 100% when there was >50% of lung involvement. The lung involvement score was also highly predictive of prognosis in this population as was reported for non-lung cancer individuals. Collectively, our results demonstrated that diagnostic and prognostic values of chest CT findings in COVID-19 are robust to the presence of lung abnormalities related to lung cancer.

Inhibition of experimental vasospasm in rats with the periadventitial administration of ibuprofen using controlled-release polymers.

BACKGROUND AND PURPOSE: The chronic phase of vasospasm after an aneurysmal subarachnoid hemorrhage may be mediated in part by early leukocyte-endothelial cell interactions. Ibuprofen is an anti-inflammatory agent that inhibits expression of certain cell adhesion molecules and therefore disrupts leukocyte-endothelial cell interactions. Its systemic administration, however, has dose-limiting side effects. We evaluated the effect of the periadventitial delivery of ibuprofen using controlled-release polymers in the rat femoral artery model of chronic posthemorrhagic vasospasm. METHODS: Before the animal studies, the release pharmacokinetics of the ibuprofen-loaded ethylene-vinyl acetate polymers were determined in vitro. Subsequently, the femoral arteries (n=266) of Fischer 344 rats (n=133) were enclosed in latex pouches bilaterally. In the toxicity study (n=15 rats), the animals were randomized into 5 dose groups in which 0%-, 10%-, 20%-, 30%-, or 50%-loaded ibuprofen polymers were evaluated. In the efficacy study, the animals were randomized into 5 time groups in which 50%-loaded ibuprofen polymers were inserted at 0 (n=58 rats), 6 (n=16), 12 (n=13), 24 (n=11), or 48 hours (n=12) after blood injection into the pouch. The rats were killed 12 days after blood exposure, at the time of maximal vasospasm in this model. Vasospasm was expressed as percent lumen patency. To evaluate the effect of ibuprofen on leukocyte migration, 8 rats were randomized into 2 groups. Macrophages and granulocytes were stained by immunohistochemistry with the use of a mouse OX-41 monoclonal antibody and counted in the periadventitial space 24 hours after blood exposure. RESULTS: In vitro pharmacokinetics showed that the 50%-loaded ibuprofen polymer released its total drug load over a 12-day period. In the toxicity study, a nonsignificant arterial vasodilatation with ibuprofen treatment was seen at higher doses, and no deleterious effects were noted on the vessel wall histologically. In the efficacy study, ibuprofen treatment resulted in significant vasospasm inhibition when treatment was initiated at 0 hour (73.7+/-4.9% versus 94.5+/-3.3% [mean+/-SEM percent lumen patency]; P<0.001) and 6 hours (69.2+/-5.7% versus 98.0+/-3.9%; P=0. 002) after blood exposure, but not at 12, 24, or 48 hours. Leukocyte immunohistochemistry showed that ibuprofen treatment resulted in significantly lower periadventitial macrophage and granulocyte counts of 25.0+/-3.9 cells per high-powered field compared with counts of 140.5+/-18.2 cells per high-powered field in the untreated vessels (P<0.001). CONCLUSIONS: The periadventitial, controlled release of ibuprofen from surgically implanted polymers significantly inhibits chronic posthemorrhagic vasospasm in this model when treatment is initiated within 6 hours of blood exposure. Vasospasm inhibition with ibuprofen correlates with a significant decrease in the number of macrophages and granulocytes in the periadventitial space. This study supports the hypothesis that inflammation mediates in part the chronic phase of posthemorrhagic vasospasm and suggests a potential alternative treatment for this condition.

Therapy of malignant brain tumors by intratumoral implantation of retroviral vector-producing cells.

Intratumoral implantation of murine cells modified to produce retroviral vectors containing the herpes simplex virus-thymidine kinase (HSV-TK) gene induces regression of experimental brain tumors in rodents after ganciclovir (GCV) administration. We evaluated this approach in 15 patients with progressive growth of recurrent malignant brain tumors. Antitumor activity was detected in five of the smaller tumors (1.4 +/- 0.5 ml). In situ hybridization for HSV-TK demonstrated survival of vector-producing cells (VPCs) at 7 days but indicated limited gene transfer to tumors, suggesting that indirect, "bystander," mechanisms provide local antitumor activity in human tumors. However, the response of only very small tumors in which a high density of vector-producing cells had been placed suggests that techniques to improve delivery and distribution of the therapeutic gene will need to be developed if clinical utility is to be achieved with this approach.

Inhibition of experimental vasospasm with anti-intercellular adhesion molecule-1 monoclonal antibody in rats.

BACKGROUND AND PURPOSE: Inflammation may play a role in delayed chronic vasospasm after aneurysmal subarachnoid hemorrhage. We investigated the role of intercellular adhesion molecule-1 (ICAM-1) and macrophage/granulocyte infiltration in the rat femoral artery model of vasospasm using systemic administration of a murine anti-ICAM-1 monoclonal antibody (MAb). METHODS: The femoral arteries (n = 72) in Sprague-Dawley rats (n = 36) were enclosed in latex pouches bilaterally. Autologous blood was injected into the pouch on one side, and saline was injected on the contralateral side. Chronic vessel narrowing was evaluated with the use of 29 rats, which were randomized into one of three groups for intraperitoneal injections: (1) anti-ICAM-1 MAb (2 mg/kg per dose, n = 10), (2) isotype-matched MAb (2 mg/kg per dose, n = 9), or (3) saline (n = 10), given at 3 hours and 3, 6, and 9 days after blood exposure. These rats were killed 12 days after blood exposure, and femoral artery lumen cross-sectional areas were determined by computerized image analysis. Saturation of ICAM-1 binding sites with this dosing schedule was evaluated by fluorescence-activated cell sorter (FACS) analysis of splenocytes. Immunohistochemical studies with objective cell counts were performed to evaluate macrophage/granulocyte infiltration at 24 hours in 7 rats, comparing anti-ICAM-1 MAb treatment (n = 4) with isotype-matched control MAb (n = 3). RESULTS: Animals treated with anti-ICAM-1 MAb showed a significant inhibition of arterial narrowing at 12 days (P = .0081), with lumen patency of 96.5 +/- 5.3% (mean +/- SEM), compared with 77.3 +/- 5.6% for isotype-matched MAb and 72.2 +/- 5.3% for saline-treated controls. FACS analysis of splenocytes from animals treated with anti-ICAM-1 MAb confirmed saturation of ICAM-1 binding sites. Vessels treated with anti-ICAM-1 MAb showed a significant decrease in inflammatory cell infiltrates, with objective macrophage/granulocyte counts of 31.3 +/- 26.6 (mean +/- SEM) per high-powered field, compared with 171.4 +/- 30.7 for isotype-matched control MAb (P = .0027). CONCLUSIONS: Anti-ICAM-1 MAb administered systemically starting 3 hours after blood exposure results in significant inhibition of chronic vasospasm in the rat femoral artery model and is correlated with a reduction in the number of infiltrating macrophages and granulocytes in the periadventitial region of blood-exposed arteries. We conclude that inflammatory changes associated with ICAM-1-mediated macrophage and granulocyte migration play an important role in the development of posthemorrhagic chronic vasospasm in this model.

Aneurysmal subarachnoid hemorrhage: prognostic features and outcomes.

The prognostic features and outcomes associated with aneurysmal subarachnoid hemorrhage (SAH) are reviewed. In the first section, the epidemiology of SAH is discussed with emphasis on prevalence, incidence, risk factors, heredity, activity, and seasonal variability. In the second section, the presentation, diagnosis, and treatment of patients with aneurysmal SAH is briefly reviewed. In the third section, the prognostic features associated with aneurysmal SAH are discussed with emphasis on neurologic condition and SAH grading scales, patient's age, aneurysm size and location, repeat hemorrhage, vasospasm, systemic disease, hypertensive response, computed tomograph features, hydrocephalus, timing of surgery, and expertise of the aneurysm center. Also in the third section, the prognostic features associated with unruptured aneurysms are discussed with emphasis on the actuarial risk of rupture, aneurysm size and location, and multiplicity of lesions. In the fourth and final section, the outcomes of aneurysmal SAH over the past 60 yrs are reviewed.

Toxicity studies and distribution dynamics of retroviral vectors following intrathecal administration of retroviral vector-producer cells.

The use of intrathecal, retroviral-mediated transfer of the herpes simplex thymidine kinase (HStk) gene and subsequent ganciclovir (GCV) administration has recently been shown to improve survival in a rat model of leptomeningeal carcinomatosis. Clinical application of this approach is attractive because access to the cerebrospinal fluid (CSF) space is relatively noninvasive and distribution of producer cells and vectors may be facilitated by circulation of CSF, overcoming distribution problems inherent in solid tumors. However, meningeal inflammation, transduction and injury to normal CNS tissue, proliferation of the xenogeneic producer cells in the subarachnoid space, immune-mediated injury, and development of hydrocephalus are possible complications of intraventricular or intrathecal administration of vector-producer cells. In addition, the dynamics of producer cell and vector distribution in the CSF are unknown. To address these issues, we evaluated the safety of this approach for gene delivery and assessed the dynamics of distribution of producer cells and retroviral vectors in rats and non-human primates. In rats, transduction of normal central nervous system (CNS) structures surrounding the subarachnoid space was evaluated after intrathecal and intraventricular injections of beta-galactosidase and HStk vector-producer cells, with and without GCV. In primates, beta-galactosidase and HStk vector-producer cells were injected intraventricularly and GCV was administered either intrathecally or intravenously. Toxicity was evaluated by neurologic examination, serial gadolinium-enhanced MRI scans of the brain, and blood and CSF profiles. A subgroup of monkeys received repeated intraventricular injection of vector-producer cells and intravenous GCV. The titer of retroviral-vector was measured in cisternal and lumbar CSF samples after repeated producer cell injection.(ABSTRACT TRUNCATED AT 250 WORDS)

In situ cyclopentenyl cytosine infusion for the treatment of experimental brain tumors.

Cyclopentenylcytosine (CPEC; NSC 375575) is a pyrimidine nucleoside analogue that has potent antitumor effects when tested in vitro and also when tested in experimental tumors outside the central nervous system. CPEC exerts its antiproliferative effect through inhibition of CTP synthetase and consequent depletion of CTP and dCTP pools required for cell replication. Due to its poor penetration of the bloodbrain barrier, CPEC has failed to demonstrate therapeutic efficacy in experimental brain tumors after systemic administration. We therefore examined the in vivo activation, distribution, and antitumor effect of CPEC after long-term regional infusion of the drug directly into experimental brain tumors in rats. HPLC analysis of CPEC incubated with homogenized human brain and brain tumor tissue showed minimal degradation of the drug over 24 h. Analysis of rat cerebral 9L gliosarcoma infused with tritium-labeled CPEC demonstrated intratumoral accumulation of the active metabolite CPEC-triphosphate and concomitant depletion of CTP to a much greater extent in tumor tissue than in the adjacent brain. Tumor tissue UTP also decreased, but no significant effects on other ribonucleoside triphosphates were detected. Only trace amounts (< 1%) of CPEC and its metabolites reached peripheral sites, including the liver and kidneys, after intratumoral infusion. Rats treated with continuous intratumoral infusion of CPEC for 4 weeks using s.c. implanted osmotic pumps survived significantly longer than control rats receiving intratumoral saline or i.p. CPEC (P < 0.0001). Long-term intratumoral infusion of CPEC was not associated with any detectable toxicity. Our results support the feasibility of using intratumoral administration of CPEC as a regional therapy for malignant brain tumors.

Adenovirally mediated gene transfer into experimental solid brain tumors and leptomeningeal cancer cells.

Among the appealing features of adenoviruses as vectors for transfer of genes into the central nervous system (CNS) are that they are not neurotoxic, they can accommodate the insertion of several large genes, they are not associated with the hazards of insertional mutagenesis, and they can be concentrated to a high-titer preparation. The authors evaluated the feasibility of using adenovirally mediated gene transfer into cultured human glioma cells and in rat models of solid brain tumors and meningeal cancer. Replication-deficient adenoviral vector particles carrying a nuclear-localizing lacZ gene were injected into established 9L cerebral gliomas in Fischer rats. In addition, the adenoviral vector was injected into the subarachnoid space, either simultaneously with intrathecal tumor inoculation or after establishing leptomeningeal cancer. The brains and spinal cords were removed at various intervals for histochemical evaluation for beta-galactosidase activity using X-Gal staining. Additional rats received a stereotactic intracerebral injection of the vector into normal brain. No clinical abnormalities were observed in the injected rats. Injection of the adenoviral vector into normal brain resulted in diffuse transduction of astrocytes, microglia, neurons, and endothelial cells at the injection site. Injection of a high-concentration vector preparation into cerebral gliomas resulted in effective tumor transduction. Intrathecal injection of the vector in rats with meningeal cancer resulted in transduction of the infiltrating tumor in the subarachnoid space when injections were given simultaneously with, or 7 days after, tumor inoculation. Transduction rates of both solid and leptomeningeal tumors correlated with the number of injected particles. These results suggest that adenoviral vectors can efficiently transduce solid brain tumors and that the vectors survive in the cerebrospinal fluid for a sufficient period of time to allow leptomeningeal tumor transduction. Adenoviral vector should be evaluated for its potential use in therapeutic gene transfer approaches in malignancies of the CNS.

Growth inhibition, tumor maturation, and extended survival in experimental brain tumors in rats treated with phenylacetate.

Phenylacetate is a naturally occurring plasma component that suppresses the growth of tumor cells and induces differentiation in vitro. To evaluate the in vivo potential and preventive and therapeutic antitumor efficacy of sodium phenylacetate against malignant brain tumors, Fischer 344 rats (n = 50) bearing cerebral 9L gliosarcomas received phenylacetate by continuous s.c. release starting on the day of tumor inoculation (n = 10) using s.c. osmotic minipumps (550 mg/kg/day for 28 days). Rats with established brain tumors (n = 12) received continuous s.c. phenylacetate supplemented with additional daily i.p. dose (300 mg/kg). Control rats (n = 25) were treated in a similar way with saline. Rats were sacrificed during treatment for electron microscopic studies of their tumors, in vivo proliferation assays, and measurement of phenylacetate levels in the serum and cerebrospinal fluid. Treatment with phenylacetate extended survival when started on the day of tumor inoculation (P < 0.01) or 7 days after inoculation (P < 0.03) without any associated adverse effects. In the latter group, phenylacetate levels in pooled serum and cerebrospinal fluid samples after 7 days of treatment were in the therapeutic range as determined in vitro (2.45 mM in serum and 3.1 mM in cerebrospinal fluid). Electron microscopy of treated tumors demonstrated marked hypertrophy and organization of the rough endoplasmic reticulum, indicating cell differentiation, in contrast to the scant and randomly distributed endoplasmic reticulum in tumors from untreated animals. In addition, in vitro studies demonstrated dose-dependent inhibition of the rate of tumor proliferation and restoration of anchorage dependency, a marker of phenotypic reversion. Phenylacetate, used at clinically achievable concentrations, prolongs survival of rats with malignant brain tumors through induction of tumor differentiation. Its role in the treatment of brain tumors and other cancers should be explored further.

Intrathecal gene therapy for malignant leptomeningeal neoplasia.

In meningeal carcinomatosis, retroviral vector-producer cells can be introduced into the thecal sac and circulate in the cerebrospinal fluid to reach malignant tumor cells in the leptomeninges, release vector particles, and selectively infect and transfer a gene of interest to these cells. Gene transfer experiments with the lacZ gene and in vitro retroviral titer measurements showed that retroviral vectors can survive in the cerebrospinal fluid, retain their infectivity, and successfully transduce tumor cells. To examine the potential of intrathecal gene therapy, we evaluated the antitumor efficacy of in situ transduction with the herpes simplex-thymidine kinase gene followed by ganciclovir therapy in a rat model of leptomeningeal neoplasia. Fischer rats were inoculated via a subarachnoid catheter implanted at the upper thoracic level, and thymidine kinase vector-producer cells were injected into the subarachnoid space the day of tumor inoculation. Seven days later, rats received ganciclovir for 14 days by daily i.p. injections (30 mg/kg/ml) or intrathecal injections (25 micrograms/kg or 600 micrograms/kg) for 14 days. To evaluate possible enhancement of tumor eradication by the ability of helper virus to package the vector in the cells and further extend gene transfer, additional rats received thymidine kinase vector-producer cells that had been previously coinfected with a replication-competent retrovirus (4070A). In all groups, control rats received i.p. or intrathecal saline injections. Ganciclovir administration i.p. resulted in significant prolongation of survival in rats given injections of thymidine kinase vector-producer cells. Injection of producer cells coinfected with the 4070A retrovirus did not improve antitumor efficacy. Intrathecal administration of ganciclovir (low and high doses) did not extend survival; histological examination of the spinal cords showed elimination of the infiltrative tumor in the leptomeninges, but residual tumor mass was present at the inoculation site, consistent with limited penetration of topical ganciclovir into the tumor. These results support the potential application of gene therapy using the thymidine kinase/ganciclovir approach for treatment of meningeal carcinomatosis.