Post-operative vision loss: analysis of 587 patients undergoing endoscopic surgery for pituitary macroadenoma

PURPOSE

Vision loss following surgery for pituitary adenoma is poorly described in the literature and cannot be reliably predicted with current prognostic models. Detailed characterization of this population is warranted to further understand the factors that predispose a minority of patients to post-operative vision loss.

MATERIALS AND METHODS

The medical records of 587 patients who underwent endoscopic transsphenoidal surgery at the Mount Sinai Medical Centre between January 2013 and August 2018 were reviewed. Patients who experienced post-operative vision deterioration, defined by reduced visual acuity, worsened VFDs, or new onset of blurry vision, were identified and analysed.

RESULTS

Eleven out of 587 patients who received endoscopic surgery for pituitary adenoma exhibited post-operative vision deterioration. All eleven patients presented with preoperative visual impairment (average duration of 13.1 months) and pre-operative optic chiasm compression. Seven patients experienced visual deterioration within 24 h of surgery. The remaining four patients experienced delayed vision loss within one month of surgery. Six patients had complete blindness in at least one eye, one patient had complete bilateral blindness. Four patients had reduced visual acuity compared with preoperative testing, and four patients reported new-onset blurriness that was not present before surgery. High rates of graft placement (10/11 patients) and opening of the diaphragma sellae (9/11 patients) were found in this series. Four patients had hematomas and four patients had another significant post-operative complication.

CONCLUSIONS

While most patients with pituitary adenoma experience favourable ophthalmological outcomes following endoscopic transsphenoidal surgery, a subset of patients exhibit post-operative vision deterioration. The present study reports surgical and disease features of this population to further our understanding of factors that may underlie vision loss following pituitary adenoma surgery. Graft placement and opening of the diaphragma sellae may be important risk factors in vision loss following ETS and should be an area of future investigation.

Academic Productivity of United States Neurosurgeons Trained Abroad

BACKGROUND

Previous research in neurosurgery has examined academic productivity for U.S. medical graduates and residents. However, associations between scholarly output and international medical education, residency training, and fellowship training are scarcely documented.

METHODS

We identified 1671 U.S. academic neurosurgeons in 2020 using publicly available data along with their countries of medical school, residency, and fellowship training. Using Scopus, h-index, number of publications, and number of times publications were cited were compiled. Demographic, subspeciality, and academic productivity variables were compared between training locations using univariate analysis and multivariable linear regression.

RESULTS

Of the current neurosurgery faculty workforce, 16% completed at least 1 component of their training abroad. Canada was the most represented international country in the cohort. Academic productivity for neurosurgeons with international medical school and/or international residency did not significantly differ from that of neurosurgeons trained in the United States. Neurosurgeons with ≥1 U.S. fellowships or ≥1 international fellowships did not have higher academic productivity than neurosurgeons without a fellowship. However, dual fellowship training in both domestic and international programs was associated with higher mean h-index (β = 6.00, 95% confidence interval 1.01 to 10.98, P = 0.02), higher citations (β = 2092.0, 95% confidence interval 460.1 to 3724.0, P = 0.01), and a trend toward higher publications (β = 36.82, 95% confidence interval -0.21 to 73.85, P = 0.051).

CONCLUSIONS

Neurosurgeon scholarly output was not significantly affected by international training in medical school or residency. Dual fellowship training in both a domestic and an international program was associated with higher academic productivity.

Abstract P39: Outcomes Across the Course of Recovery From Subarachnoid Hemorrhage

Introduction: Data on progression of recovery after aneurysmal subarachnoid hemorrhage (aSAH) is rare and limited to small samples. We sought to characterize recovery after SAH in a secondary analysis of six SAH trials.

Methods: Individual data on 3,717 patients from CONSCIOUS-1, ISAT, IHAST, trials of erythropoietin and statins, NEWTON-1, and NEWTON-2 was included. Outcome was described with the Glasgow Outcomes Scale (GOS). Proportions of GOS scores between the first and second time-point were compared using chi-square tests. Rates of improvement (final GOS > initial GOS), no change (final GOS = initial GOS), and worsening (final GOS < initial GOS) and the differences between initial and final GOS scores were calculated.

Results: There were improvements in outcomes across the entire cohort (p<0.001) and from 30 days to three months (p<0.001), discharge to three months (p<0.001), six weeks to three months (p<0.001), and two months to one year (p<0.001). 907 (26%) of patients improved their outcome, while 2,228 (64%) had no change and 336 (9.7%) worsened. Of the 907 who improved, 773 (85%) improved by one GOS point, 128 (14%) improved by two points, and six (0.7%) improved by three points. Of patients with initial GOS scores of 2, 62 (38%) remained unchanged, while 91 (55%) improved and 11 (6.7%) died. Patient cohorts with initial WFNS grades of 1 (p<0.001), 2 (p<0.001), 3 (p=0.004), and 4 (p<0.001) improved their GOS scores.

Conclusions: Across most time-frames, many SAH patients can be expected to recover, while a few will regress. Furthermore, even patients with the poorest initial neurological grades and outcomes showed improvement.

Abstract MP12: Drivers of Rescue Therapy Efficacy for Vasospasm Following Aneurysmal Subarachnoid Hemorrhage: A Propensity-Score Matched Analysis With Machine Learning

Introduction: One of the foremost challenges in subarachnoid hemorrhage (SAH) management is understanding which patient characteristics and treatment decisions lead to good outcomes. This study uses novel game theory-based methods in explainable machine learning (ML) and propensity-score matching to elucidate the clinical factors driving outcomes following rescue therapy for post-SAH vasospasm.

Methods: Data for patients with post-SAH angiographic or symptomatic vasospasm were obtained from six clinical trials and observational studies in the Subarachnoid Hemorrhage International Trialists (SAHIT) repository. Gradient boosting ML models were constructed for each patient to predict the probability of receiving rescue therapy and 3-month Glasgow Outcome Scale (GOS) scores. Shapley Additive Explanation (SHAP) values were calculated to quantify feature importance and interaction effects. Variables with high SHAP importance in predicting rescue therapy were used in a propensity score-matched analysis of rescue therapy and 3-month GOS scores.

Results: A total of 1,532 patients were included. SAH characteristics and neurological sequelae, but not admission neurological scores, heavily influenced the probability of receiving rescue therapy. Comparing feature importances showed cerebral ischemia/infarction was invariably linked to poor outcome, while other important predictors of outcome varied by rescue type. Higher blood pressures and fewer postoperative days until vasospasm treatment were more important for predicting worse outcome following interventional rescue, while high admission WFNS grade and pneumonia were important predictors of worse outcome for non-interventional rescue. Finally, in a propensity score-matched analysis guided by SHAP-based variable selection, rescue therapy was associated with higher odds of 3-month GOS of 4-5 (odds ratio: 1.63; 95%CI 1.22-2.17; p=0.001).

Conclusion: Rescue therapy for vasospasm was associated with good functional outcomes. Future randomized trials focusing on preventative or therapeutic interventions may be able to demonstrate improvements in clinical outcomes. Insights from these models may help improve patient selection criteria and trial designs for rescue therapy.

Abstract P43: The Importance of Medical Complications in Determining Outcomes After Subarachnoid Hemorrhage

Introduction: Despite their high prevalence, prospective data on medical complications after aneurysmal subarachnoid hemorrhage (aSAH) and their contribution to functional outcome are sparse. We review rates of such events and correlate them to functional outcomes in three prospective datasets of patients with aSAH.

Methods: Patients from two clinical trials (NEWTON-2, CONSCIOUS-1) and one clinical registry (Subarachnoid Hemorrhage Outcomes Project) were included. A good functional outcome was defined as a Glasgow Outcomes Scale (GOS) score of 4 or 5. Seventeen medical complications were assessed and their association with functional outcomes was determined with multivariable logistic regression. The variance in outcome explained by medical complications was calculated using difference in Nagelkerke’s R-squared.

Results: Among the 1,430 patients, the most common complications were fever (564, 39%), anemia (410, 29%), and pneumonia (341, 24%). Patients who suffered any complication (OR: 0.45; 95% CI: 0.36 to 0.57; p<0.001) were less likely to have a good functional outcome in unadjusted analyses. In multivariable analysis, complications independently associated with lower rates of good functional outcome were anemia (OR: 0.60; 95% CI: 0.44 to 0.80; p<0.001), cardiac arrest (OR: 0.14; 95% CI: 0.05 to 0.37; p<0.001), pneumonia (OR: 0.48; 95% CI: 0.35 to 0.66; p<0.001), pulmonary edema (OR: 0.67; 95% CI: 0.45 to 0.99; p=0.047), and acute kidney injury (OR: 0.34; 95% CI: 0.12 to 0.98; p=0.047). A panel of eleven medical complications explained 8% of the variation in functional outcomes.

Conclusions: Medical complications contribute to functional outcomes after aSAH, but their individual contributions to outcomes are relatively small. This should be noted when considering trials directed at preventing or treating any one complication and raises the question of studying comprehensive neurointensive care packages in the future.

The Role of Advanced Endoscopic Resection of Diverse Skull Base Malignancies: Technological Analysis during an 8-Year Single Institutional Experience

Background Resection of skull base malignancies poses complex pathological and treatment-related morbidities. Recent technological advancements of endoscopic endonasal surgery (EES) offer the ability to reexamine traditional treatment paradigms with endoscopic procedures. The utility of EES was quantitatively examined in a longitudinal series with attention to morbidities and postoperative outcomes.

Methods A single-center retrospective review was performed of all malignant sinonasal tumors from 2010 to 2018. Patients with purely EES were selected for analysis. Disease features, resection extent, complications, adjuvant treatment, recurrence, and survivability were assessed. Despite the mixed pathological cohort, analysis was performed to identify technical aspects of resection.

Results A total of 68 patients (47.6% males and 52.4% females, average age: 60.3 years) were included. A diversity of histotypes included clival chordoma (22.1%), olfactory neuroblastoma (14.7%), squamous cell carcinoma (11.8%), and adenoid cystic carcinoma (11.8%). Gross total resection (GTR) was achieved in 83.8% of cases. Infection (4.4%) and cerebrospinal fluid leak (1.5%) were the most common postoperative complications. Total 46 patients (67.6%) underwent adjuvant treatment. The average time between surgery and initiation of adjunctive surgery was 55.7 days.

Conclusion In our 8-year experience, we found that entirely endoscopic resection of mixed pathology of malignant skull base tumors is oncologically feasible and can be accomplished with high GTR rates. There may be a role for EES to reduce operative morbidity and attenuate time in between surgery and adjuvant treatment, which can be augmented through recent mixed reality platforms. Future studies are required to systematically compare the outcomes with those of open surgical approaches.

MTXPK.org: A Clinical Decision Support Tool Evaluating High-Dose Methotrexate Pharmacokinetics to Inform Post-Infusion Care and Use of Glucarpidase

Methotrexate (MTX), an antifolate, is administered at high doses to treat malignancies in children and adults. However, there is considerable interpatient variability in clearance of high‐dose (HD) MTX. Patients with delayed clearance are at an increased risk for severe nephrotoxicity and life‐threatening systemic MTX exposure. Glucarpidase is a rescue agent for severe MTX toxicity that reduces plasma MTX levels via hydrolysis of MTX into inactive metabolites, but is only indicated when MTX concentrations are > 2 SDs above the mean excretion curve specific for the given dose together with a significant creatinine increase (> 50%). Appropriate administration of glucarpidase is challenging due to the ambiguity in the labeled indication. A recent consensus guideline was published with an algorithm to provide clarity in when to administer glucarpidase, yet clinical interpretation of laboratory results that do not directly correspond to the algorithm prove to be a limitation of its use. The goal of our study was to develop a clinical decision support tool to optimize the administration of glucarpidase for patients receiving HD MTX. Here, we describe the development of a novel 3‐compartment MTX population pharmacokinetic (PK) model using 31,672 MTX plasma concentrations from 772 pediatric patients receiving HD MTX for the treatment of acute lymphoblastic leukemia and its integration into the online clinical decision support tool, MTXPK.org. This web‐based tool has the functionality to utilize individualized demographics, serum creatinine, and real‐time drug concentrations to predict the elimination profile and facilitate model‐informed administration of glucarpidase.

Variability in Clinical Presentation and Pathologic Implications of Ectopic Pituitary Tumors: Critical Review of Literature

OBJECTIVE

Pituitary tumors are common, well-described skull base tumors of sellar origin. However, there are reports of rare ectopic pituitary tumors that are found exclusively outside of the sella turcica. Ectopic pituitary tumors have not been holistically analyzed. This study describes presentation and clinical patterns found among patients with ectopic pituitary tumors.

METHODS

A comprehensive review of the literature was performed for clinical descriptions of ectopic pituitary tumors. Reports of 85 applicable cases were evaluated.

RESULTS

The most common locations of ectopic pituitary tumors were the sphenoid sinus, clivus, suprasellar space, nasopharynx, and cavernous sinus. The majority of ectopic pituitary tumors were reported as being functional secretory tumors; they were statistically significantly more likely to be functional tumors than sellar pituitary tumors. Adrenocorticotrophic hormone, prolactin, growth hormone, and thyroid-stimulating hormone-secreting tumors were most commonly found. Bone invasion was reported in more than one third of the cases, and malignant transformations were reported in 6 cases. A large majority of patients presented with hormonal, neurologic, or physiologic symptoms.

CONCLUSIONS

Ectopic pituitary tumors are a rare entity of pituitary tumors with a presentation that can mimic those of other skull base tumors. Clinical presentation often correlates to location of the tumor. Ectopic pituitary tumors were significantly more likely to be functional secretory tumors. They may also exhibit more aggressive behavior than sellar-located tumors. Ectopic pituitary tumors may be part of a spectrum of presenting pathologies. Further genetic or genomic analysis is necessary to better understand their pathogenesis and clinical presentations.

Reducing Parental Uncertainty Around Childhood Cancer: Implementation Decisions and Design Trade-Offs in Developing an Electronic Health Record-Linked Mobile App

Background

Parents of children newly diagnosed with cancer are confronted with multiple stressors that place them at risk for significant psychological distress. One strategy that has been shown to help reduce uncertainty is the provision of basic information; however, families of newly diagnosed cancer patients are often bombarded with educational material. Technology has the potential to help families manage their informational needs and move towards normalization.

Objective

The aim of this study was to create a mobile app that pulls together data from both the electronic health record (EHR) and vetted external information resources to provide tailored information to parents of newly diagnosed children as one method to reduce the uncertainty around their child’s illness. This app was developed to be used by families in a National Institutes of Health (NIH)-funded randomized controlled trial (RCT) aimed at decreasing uncertainty and the subsequent psychological distress.

Methods

A 2-phase qualitative study was conducted to elicit the features and content of the mobile app based on the needs and experience of parents of children newly diagnosed with cancer and their providers. Example functions include the ability to view laboratory results, look up appointments, and to access educational material. Educational material was obtained from databases maintained by the National Cancer Institute (NCI) as well as from groups like the Children’s Oncology Group (COG) and care teams within Cincinnati Children’s Hospital Medical Center (CCHMC). The use of EHR-based Web services was explored to allow data like laboratory results to be retrieved in real-time.

Results

The ethnographic design process resulted in a framework that divided the content of the mobile app into the following 4 sections: (1) information about the patient’s current treatment and other data from the EHR; (2) educational background material; (3) a calendar to view upcoming appointments at their medical center; and (4) a section where participants in the RCT document the study data. Integration with the NCI databases was straightforward; however, accessing the EHR Web services posed a challenge, though the roadblocks were not technical in nature. The lack of a formal, end-to-end institutional process for requesting Web service access and a mechanism to shepherd the request through all stages of implementation proved to be the biggest barrier.

Conclusions

We successfully deployed a mobile app with a custom user interface that can integrate with the EHR to retrieve laboratory results and appointment information using vendor-provided Web services. Developers should expect to face hurdles when integrating with the EHR, but many of them can be addressed with frequent communication and thorough documentation. Executive sponsorship is also a key factor for success.

Trial Registration

ClinicalTrials.gov NCT02505165; https://clinicaltrials.gov/ct2/show/NCT02505165 (Archived by WebCite at http://www.Webcitation.org/6r9ZSUgoT)

Myocardial hypo-enhancement on resting computed tomography angiography images accurately identifies myocardial hypoperfusion

OBJECTIVE

The objective of this study was to test the diagnostic accuracy of myocardial CT perfusion (CTP) imaging using color and gray-scale image analysis.

BACKGROUND

Current myocardial CTP techniques have varying diagnostic accuracy and are prone to artifacts that impair detection. This study evaluated the diagnostic accuracy of color and/or gray-scale CTP and the application of artifact criteria to detect hypoperfusion.

METHODS

Fifty-nine prospectively enrolled patients with abnormal single-photon emission computed tomography (SPECT) studies were analyzed. True hypoperfusion was defined if SPECT hypoperfusion corresponded to obstructive coronary stenoses on CT angiography (CTA). CTP applied color and gray-scale myocardial perfusion maps to resting CTA images. Criteria for identifying artifacts were also applied during interpretation.

RESULTS

Using combined SPECT plus CTA as the diagnostic standard, abnormal myocardial CTP was present in 33 (56%) patients, 19 suggesting infarction and 14 suggesting ischemia. Patient-level color and gray-scale myocardial CTP sensitivity to detect infarction was 90%, with specificity 80%, and negative and positive predictive value of 94% and 68%. To detect ischemia or infarction, CTP specificity and positive predictive value were 92% whereas sensitivity was 70%. Gray-scale myocardial CTP had slightly lower specificity but similar sensitivity. Myocardial CTP artifacts were present in 88% of studies and were identified using our criteria.

CONCLUSIONS

Color and gray-scale myocardial CTP using resting CTA images identified myocardial infarction with high sensitivity as well as infarction or ischemia with high specificity and positive predictive value without additional testing or radiation. Color and gray-scale CTP had slightly better specificity than gray-scale alone.

Lineage differentiation of canine lymphoma/leukemias and aberrant expression of CD molecules

Multiparameter flow cytometry analysis and specific cluster differentiation (CD) molecules were used to determine the expression profiles of B- and T-cell antigens on lymph node preparations from 59 dogs with generalized or multisystemic lymphoma. Lymph node samples from 11 healthy dogs were labeled to validate the specificity of antibodies and to formulate guidelines for interpretation of the results obtained from lymphoma samples. In normal lymph nodes, T-lymphocytes expressing CD3, CD4, or CD8 beta represented 59+/-11%, 43+/-8%, or 16+/-5% of the total cells, whereas B-lymphocytes expressing either CD21 or surface IgM (IgM) represented 37+/-9% or 14+/-5%, respectively. Small lymphocytes could be distinguished from large lymphocytes by forward light scatter. Of the patient samples 29 different breeds were represented with Golden and Labrador retriever being the most common. The lymphoma samples segregated into three groups based on CD antigen expression. Thirty cases predominantly expressed one or more combinations of CD79a, IgM, and CD21 representing a B-cell lineage. Three B-cell cases also expressed the stem cell antigen, CD34. Sixteen cases expressed one or more combinations of CD3, CD4, and CD8 consistent with a T-cell lineage and CD3+CD4+CD8--phenotype was the most common. Thirteen cases showed a mixed expression profile for T- and B-cell antigens and in three cases CD14 was highly expressed. Clinical response was poorest for T-cell lymphomas. Leukemic states occurred in all three phenotypes; but mixed cell cases had the greatest proportion. Dual immunofluorescence staining confirmed co-expression of T-cell (CD3) and B-cell antigens (CD79a or CD21) on neoplastic lymphocytes of six mixed cell cases. In one mixed cell case, dual immunostaining identified lymphocyte populations that stained mutually exclusive for CD79a and CD3. Six mixed cell lymphomas tested by PCR showed clonality for rearranged antigen receptor. Four cases that were CD79a+CD3+ had TCRgamma chain gene rearrangements, whereas two cases that were CD3+CD8+CD21+ had Ig heavy chain rearrangement. One case expressing multiple CD molecules (CD3+CD8+CD21+CD14+) was PCR negative for both Ig and TCRgamma gene rearrangement and could not be classified into a B- or T-cell lineage. We show for the first time co-expression of B- and T-cell markers on lymphoma cells that had specific T- or B-cell gene rearrangements. These findings suggest that aberrant CD molecule expression is not an uncommon finding in canine lymphomas and is a useful diagnostic marker for malignancy.

Simultaneous flow cytometric analysis of phagocytosis and oxidative burst activity in equine leukocytes

This paper describes a method for simultaneously measuring phagocytosis and oxidative burst activity in equine peripheral blood leukocytes by flow cytometry. Opsonized propidium iodide-labelled Staphylococcus aureus (PI-Sa) was used to measure the uptake of bacteria by equine phacocytes and the oxidative burst activity by oxidation of dihydrorhodamine 123. The requirements to achieve optimal activity of phagocytosis and oxidative burst are described. The advantage of the simultaneous technique is that it provides both independent and comparative values for phagocytosis and the oxidative burst, for the detection of impaired mechanisms of microbial destruction. Furthermore, the technique allows evaluation of opsonization activity in this context.

Characterization of peripheral blood and pulmonary leukocyte function in healthy foals

Studies in infants and foals indicate an age-dependent maturation of peripheral lymphocyte subsets. The age-dependent relationship for maturation of cellular immune responses, such as phagocytosis and lymphocyte responses of the peripheral and pulmonary-derived leukocytes, has not been characterized in foals. Lymphocyte subpopulations, mitogen stimulation response of lymphocytes, lymphokine-activated killing cell activity, phagocytosis and oxidative burst activity, and serum immunoglobulin (Ig) classes G and M concentrations were determined in developing foals. This study illustrates age-dependent changes in immunoglobulin class concentrations, lymphocyte subsets, and EqMHC Class II expression in cells of the peripheral blood and lungs of developing neonatal-to-weanling foals. The increase in peripheral blood and BAL B-lymphocytes and serum immunoglobulins in developing foals suggests expansion of immune cell populations during a time in which environmental pathogen exposure is great. General immune function, mitogenic responses, LAK cell activity, opsonized phagocytosis, and oxidative burst activity of newborns was similar to the adult horse. Total immune-cell numbers, rather than function, seemed to be the limiting factor in the development of the equine neonatal immune system. There was an age-related percent increase in the appearance of pulmonary lymphocytes, but a percent decrease in macrophages. Although development of the respiratory immune system follows changes in the peripheral blood, cellular expansion, activation, and migration may occur at a slower pace, making the respiratory environment susceptible to pathogens prior to optimal immune system maturity.

Isotype-specific antibodies in horses and dogs with immune-mediated hemolytic anemia

Classes of antibody bound to erythrocytes were determined using direct immunofluorescence (DIF) flow cytometry in 3 horses and 12 dogs with immune-mediated hemolytic anemia (IMHA). Background levels of antibody binding were determined in samples from 12 horses and 12 dogs that were free of clinical disease. The range of nonspecific binding of a fluorescein isothiocyanate (FITC)-conjugated goat anti-equine immunoglobulin G (IgG) was 19.9-36.7%, but was eliminated by the use of the F(ab')2 fragment of FITC-conjugated goat anti-equine IgG. Background binding by other class-specific antibodies to equine and canine erythrocytes was negligible. The DIF results were compared to the direct antiglobulin (Coombs') test in 5 horses and 20 dogs with anemia. The former assay was more sensitive in dogs with IMHA than was the Coombs' test (100% versus 58%). In contrast, the Coombs' test had better specificity than the DIF assay (100% versus 87.5%, respectively). Using clinical parameters or response to therapy as the comparison, the positive and negative predictive values for the DIF test were 92% and 100% compared to the values of the Coombs' test of 100% and 62%. The DIF assay detected low levels of cells bound with antibody (<30%) in 5 dogs that were Coombs' test-negative. For both species, performance of the DIF test was independent of the prozone effect. Five dogs with IMHA had IgG and IgM on erythrocytes, 5 had IgG, and 2 had IgM. Three horses had surface-bound IgG, including a horse with suspected penicillin-induced IMHA, a foal with neonatal isoerythrolysis, and a foal with clostridial septicemia. The DIF method was valuable in monitoring the response to therapy in the foal with neonatal isoerythrolysis.

Peripheral blood lymphocyte subpopulations and immunoglobulin concentrations in healthy foals and foals with Rhodococcus equi pneumonia

Infectious diseases are common in foals aged 1-5 months. The objectives of this investigation were to evaluate immunologic parameters in foals from birth to weaning to establish reference values for the proportion of circulating lymphocytes that were helper (CD4+) or cytotoxic (CD8+) T cells, or B cells; to measure serum immunoglobulin (IgM and IgG) concentrations; and to compare these immunologic parameters to values in foals with naturally occurring Rhodococcus equi pneumonia and in adult horses. Peripheral blood lymphocyte subpopulations were determined by flow cytometric analysis, and serum IgG and IgM concentrations were determined by radial immunodiffusion. Flow cytometric analysis of lymphocyte subpopulations suggested age-related changes in the cell-mediated immune system in horses. Absolute circulating CD4+ and CD8+ T lymphocytes and B cells increased linearly up to 3 months of age. Circulating B cell concentrations from birth to 6 months of age were greater than values in adult horses and the lymphocyte differences among the age groups are mainly due to variation in B lymphocytes. Both absolute and proportional B cell concentrations were greater in foals with R equi pneumonia than in healthy foals at the same age. The increase in absolute cell counts of each subpopulation was dependent on the increase of absolute peripheral blood lymphocyte count. Serum IgG concentration increased linearly from 1 to 3 months of age, and serum IgM concentrations increased from 1 to 6 months of age. These data suggest age-dependent cell-mediated and humoral development in young foals.

The effect of different bovine viral diarrhea virus genotypes and biotypes on the metabolic activity and activation status of bovine peripheral blood mononuclear cells

The effects of cytopathic (cp) and non-cytopathic (ncp) bovine viral diarrhea virus (BVDV) on the cellular metabolic activity and activation status of bovine peripheral blood mononuclear cells (PBMC) were investigated. Cellular DNA and protein synthesis was determined by [3H]thymidine and [3H]valine incorporation, respectively, in phytohemagglutinin (PHA)-stimulated PBMC. All cp strains and most ncp BVDV strains significantly inhibited DNA synthesis in PHA-stimulated PBMC; however, only cp BVDV strains inhibited protein synthesis. A plaque assay and immunofluorescence test confirmed productive BVDV infection of PBMC. In addition, viral RNA synthesis was demonstrated in BVDV-infected PBMC by RT-PCR. The interleukin-2 receptor (IL-2R) was used as a marker for the activation status of BVDV-infected PBMC. The expression of IL-2R was preserved in virus-infected cells, even though DNA and protein synthesis was suppressed. These findings suggest a novel mechanism of virus-induced immune suppression in which BVDV inhibits basic metabolic activities of bovine PBMC. The activation signals, however, are maintained.

Cytologic evaluation of bronchoalveolar lavage fluid from horses with recurrent airway obstruction after aerosol and parenteral administration of beclomethasone dipropionate and dexamethasone, respectively

OBJECTIVE

To determine cytologic changes in horses with recurrent airway obstruction (heaves) after administration of aerosolized beclomethasone dipropionate and dexamethasone parenterally.

ANIMALS

6 horses with inducible and reversible heaves.

PROCEDURE

Episodes of heaves were induced by exposure to moldy hay and straw for 7 days. Horses were assigned to treatment groups (aerosolized beclomethasone, parenterally administered dexamethasone, aerosolized propellant), and pulmonary inflammation was evaluated by serial cytologic examination of bronchoalveolar lavage (BAL) fluid samples obtained on days 0, 7, 10, 14, and 21. Total and differential cell counting and phenotypic analysis of lymphocyte subpopulations in BAL fluid were performed.

RESULTS

7 days of natural challenge induced neutrophilic inflammation. Neutrophil counts in BAL fluid were reduced in beclomethasone- and dexamethasone-treated horses on days 10 and 14 but rebounded to pretreatment values on day 21. The proportion of proinflammatory lymphocyte subpopulations (CD4+ and B+) and MHC class-II antigen expression were increased on days 14 and 21 in propellant-treated horses, compared with beclomethasone- and dexamethasone-treated horses.

CONCLUSIONS

Aerosolized beclomethasone attenuated neutrophilic pulmonary inflammation and prevented alteration in lymphocyte subpopulations in horses with heaves. Results were similar to the response associated with parenterally administered dexamethasone. Short-term administration of aerosolized beclomethasone without minimizing environmental allergen exposure is not expected to provide prolonged anti-inflammatory benefit for horses with heaves.

Immunologic function in horses after non-specific immunostimulant administration

Inactivated Propionibacterium acnes is a biologic response modifier for treatment of non-specific respiratory disease in horses. The objectives of this investigation were to determine alterations in phagocytic activity, phenotypic expression of lymphocyte subpopulations and lymphokine-activated killing cell response in healthy young horses. Samples were collected on day 0, 7 and 14 of the investigation. Blood samples were obtained via jugular venipuncture and pulmonary leukocytes were recovered via bronchoalveolar lavage (BAL). Commercially available P. acnes (Eqstim) was administered intravenously on days 7, 9 and 11 of the investigation. Fever was observed on days 8 and 10, indicating immune reaction. Total peripheral blood white cell count was increased (P < 0.05) on day 14 after P. acnes administration compared to values on days 0 and 7. Total BAL fluid cell count decreased (P < 0.01) on day 14 compared to values on days 0 and 7, which was characterized by a decrease in total lymphocyte (P < 0.01) and macrophage (P < 0.01) counts. The proportion of lymphocytes in BAL fluid decreased (P < 0.005) on day 14 compared to values on days 0 and 7, and the proportion of macrophages increased (P < 0.005) on day 14 compared to values on days 0 and 7. P. acnes administration increased the total (P < 0.05) and proportional (P < 0.05) counts of CD4+ T lymphocytes in peripheral blood. Bronchoalveolar lavage fluid proportion of CD4+ (P < 0.05), CD5+ (P < 0.001) and MHC II (P < 0.05) lymphocytes increased on day 14 after P. acnes administration compared to values on days 0 and 7. Nonopsonized phagocytic activity in peripheral blood increased (P < 0.0005) on day 14 after P. acnes administration compared to values on days 0 and 7. Lymphokine-activated killing cell activity in peripheral blood and BAL fluid leukocytes was enhanced (P < 0.005) on day 14 after P. acnes administration compared to values on days 0 and 7. Serum IgG and IgM concentrations were within laboratory reference values and were not altered by administration of P. acnes. This investigation demonstrated immunostimulant and immunomodulatory properties of P. acnes, characterized by increased CD4+ T lymphocyte expression and LAK activity in peripheral blood and BAL fluid, increased nonopsonized phagocytosis in peripheral blood leukocytes and decreased pulmonary cellularity.

Use of multiple antigen substrates to detect antinuclear antibody in canine sera

The presence of antinuclear antibody in serum has been used to serologically support the clinical diagnosis of systemic lupus erythematosus. Most often, diagnostic support is conferred if the titer is above a "cut-off" value determined by the particular laboratory. The precision estimates of these commonly used serological assays are high. The arithmetic and geometric precisions estimates of fluorescent antinuclear antibody (FANA) assays were determined utilizing sera from dogs with polysystemic signalment suggestive of SLE. A simple score assay was found to have improved precision over FANA endpoint titrations on Hep-2 or cryostat, rat liver substrates. In one case, the precision improved from an arithmetic coefficient of variation of 25.6% (HEp-2, endpoint dilution, FANA titers) or 19.7% (rat liver cryostat substrate FANA titers) to 15.5%. Geometric coefficients of variation followed similar trends. Further, the score values for dogs with SLE were considerably higher (mean = 3.28) than for clinically normal dogs (mean = 0.20). The score system was more precise than FANA endpoint titers and therefore may be useful for diagnostic purposes, especially when FANA titers are negative or low.

Radiographic studies for women with recurrent urinary tract infections

Recent reports have suggested that roentgenographic examination of the urinary tract has little importance in the management of women with recurrent urinary tract infections. We evaluated 78 women with recurrent urinary tract infection with excretory urograms and voiding cystourethrograms. Of the 78 women 5 (6 per cent) had major structural urologic abnormalities requiring further therapy. All women with major abnormalities had risk factors. These risk factors included childhood urinary tract infection, elevated serum creatinine, documented fever more than 38(5), relapsing infection, a history of urinary calculi, infection with a urea-splitting organism. neurologic bladder dysfunction, a history of genitourinary surgery and asymptomatic bacteriuria. We believe that roentgenographic evaluation of the urinary tract is of benefit in selected women with recurrent urinary tract infections.