Development and evaluation of a lateral flow-based portable optical system for determination of the pregnancy status of dairy cows.

Our objectives were to develop and evaluate an integrated system consisting of a lateral-flow immunoassay (LFIA) and an electronic portable imaging device for determination of pregnancy status of cows based on plasma concentrations of pregnancy-specific protein B (PSPB). Experiment 1 was conducted to test the performance of the LFIA for PSPB (PSPB-LFIA) whereas experiment 2 was conducted to evaluate the performance of the integrated system including both the LFIA and imaging device. The PSPB-LFIA strips were made of nitrocellulose membrane with polystreptavidin, anti-mouse antibody, Europium-anti-PSPB conjugates, and biotin-PSPB. After adding buffer and plasma in a 96-well plate, strips were dipped to initiate flow and were read in a fluorescence microscope to estimate PSPB concentrations based on the test-to-control line signal (T/C ratio). The T/C ratio of standards was linearly associated with PSPB (R2 = 0.99 in both experiments) concentrations. To test the ability to identify pregnant cows of the PSPB-LFIA only or the integrated system, plasma samples were collected and transrectal ultrasonography (TUS) was conducted 29 to 35 d post AI in lactating Holstein cows (Experiment 1: n = 83; Experiment 2: n = 205). A cow was considered pregnant (Preg) if concentrations of PSPB in plasma obtained by ELISA were ≥2 ng/mL or if an embryo was visible by TUS. In Experiment 1, the accuracy of the PSPB-LFIA compared with ELISA was 92.7% (91.2% Se; 96.1% Sp; 98.1% PPV; 83.3% NPV) and compared with TUS was 90.4% (100% Se; 78.9% Sp; 84.9% PPV; 100% NPV). The agreement between LFIA and ELISA (kappa = 0.84; 95%CI 0.71-0.96) or LFIA and TUS (kappa = 0.80; 95%CI 0.67-0.93) as methods to classify cows as Preg or Non-Preg was high. In Experiment 2, the accuracy of the PSPB-LFIA compared with ELISA was 96.1% (93.8% Se; 100% Sp; 100% PPV; 90.5% NPV) and compared with TUS was 92.2% (99.0% Se; 84.7% Sp; 87.6% PPV; 98.8% NPV). The agreement between LFIA and ELISA (kappa = 0.92; 95%CI 0.86-0.97) or LFIA and TUS (kappa = 0.84; 95%CI 0.77-0.92) as methods to classify cows as Preg or Non-Preg was high. We conclude that a system integrating a fluorescence-based LFIA and an optical reader was effective for classifying cows as pregnant or not pregnant based on estimations of plasma concentrations of PSPB. This novel system serves as a platform for further development of on-farm pregnancy testing tools based on measurement of biomarkers of pregnancy in bodily fluids of cattle.

Evaluation of a field deployable, high-throughput RT-LAMP device as an early warning system for COVID-19 through SARS-CoV-2 measurements in wastewater.

Quantification of SARS-CoV-2 RNA copies in wastewater can be used to estimate COVID-19 prevalence in communities. While such results are important for mitigating disease spread, SARS-CoV-2 measurements require sophisticated equipment and trained personnel, for which a centralized laboratory is necessary. This significantly impacts the time to result, defeating its purpose as an early warning detection tool. The objective of this study was to evaluate a field portable device (called MINI) for detecting SARS-CoV-2 viral loads in wastewater using real-time reverse transcriptase loop-mediated isothermal amplification (real-time RT-LAMP). The device was tested using wastewater samples collected from buildings (with 430 to 1430 inhabitants) that had known COVID-19-positive cases. Results show comparable performance of RT-LAMP against reverse transcriptase polymerase chain reaction (RT-qPCR) when detecting SARS-CoV-2 copies in wastewater. Both RT-LAMP and RT-qPCR detected SARS-CoV-2 in wastewater from buildings with at least three positive individuals within a 6-day time frame prior to diagnosis. The large 96-well throughput provided by MINI provided scalability to multi-building detection. The portability of the MINI device enabled decentralized on-site detection, significantly reducing the time to result. The overall findings support the use of RT-LAMP within the MINI configuration as an early detection system for COVID-19 infection using wastewater collected at the building scale.

Operational changes to the lupus intervention fatigue trial as a result of COVID-19: An update to the study protocol.

Background: The coronavirus disease 2019 (COVID-19) global pandemic drastically impacted the health system and the research community. As a result, research institutions and funding agencies recommended a moratorium on conducting in-person research and study enrollment until protocol changes to protect participant safety were approved and implemented. We detail the operational modifications made to the Lupus Intervention Fatigue Trial (LIFT) protocol and summarize how we met the varied challenges created by COVID-19. Methods: We evaluated study protocols and determined that scheduling, acquiring consent, in-person assessments and intervention baseline visits, patient reported outcomes, and data processing procedures needed modification. Results: Operational modifications were made to ensure study progress while adhering to COVID-19 restrictions. Major changes included electronic consent, remote baseline visits for those in the intervention, self-report outcome measures at home via emailed weblinks, and telemedicine physician assessment visits. The collection of safety labs presented the largest challenge since this required an in-person visit to a laboratory. The study team elected to delay this up to one month after the physician assessment. All follow-up visits were completed, and no participants withdrew from the study. Conclusion: LIFT was severely impacted by COVID-19. We provide insight into how our study protocol was modified without compromising the integrity of the primary and secondary outcomes of the study. The modifications utilized by the LIFT study resulted in efficiencies that will be included in a revised protocol and may serve as a useful example for other behavioral interventions to adapt their research studies.

Erratum to "An automated controlled-release device for intravaginal hormone delivery" (JDS Commun. 1:15-20).

[This corrects the article DOI: 10.3168/jdsc.2020-18816.].

A lateral flow-based portable platform for determination of reproductive status of cattle.

Our objective was to develop and validate a tool integrating a disposable fluorescence-based lateral flow immunoassay (LFIA) coupled with a portable imaging device for estimating circulating plasma concentrations of progesterone (P4). First, we developed and optimized a competitive LFIA test strip to measure P4 in bovine plasma. The LFIA design included a sample pad, a conjugate pad that stores R-phycoerythrin-anti-P4 conjugates, a glass-fiber spacer pad, a nitrocellulose membrane with printed test and control lines, and a cellulose-fiber absorbent pad. To perform a test, 20 µL of plasma and 50 µL of running buffer were added on the sample pad. After 3 min, 45 µL of running buffer was added to initiate sample flow. After allowing 15 min to stabilize the colorimetric signal, strips were introduced in an LFIA portable reader wirelessly linked to a laptop to determine P4 concentration based on test-to-control-line signal (T/C ratio). In a series of experiments (n = 6), the ability of the LFIA to differentiate plasma samples with ≥1 or <1 ng/mL of P4 was evaluated. For each experiment, a calibration curve was constructed using plasma with known concentrations of P4 (0.1 to 3.7 ng/mL; n = 5). The resulting linear equation was then used to determine a T/C ratio cutoff to differentiate samples with ≥1 or <1 ng/mL of P4. In addition, to evaluate the ability of the platform to assign samples to P4 concentration groups without a calibration curve for individual batches, we performed a receiver operating characteristic analysis to identify a single cutoff value for T/C ratio that could potentially be used for all batches. Overall, calibration curves showed a linear relationship between T/C ratio and P4 levels (mean coefficient of determination = 0.74; range 0.42 to 0.99). Next, plasma samples from lactating dairy cows (n = 58) were tested in triplicate to determine the ability of the LFIA system to differentiate plasma samples with ≥1 or <1 ng/mL of P4 using a RIA for P4 as reference test. Overall, the LFIA assay correctly classified 90% of the samples, with 97% sensitivity, 83% specificity, 85% positive predictive value, and 96% negative predictive value. Agreement between the tests was substantial (kappa = 0.79; 95% confidence interval 0.64 to 0.95). When using a single cutoff value for T/C ratio selected by receiver operating characteristic analysis, sensitivity and specificity to determine CL presence were 97 (95% confidence interval 82 to 99) and 79% (95% confidence interval 60 to 92), respectively. These data suggest that the developed portable LFIA system can accurately differentiate plasma samples with ≥1 or <1 ng/mL of P4.

An automated controlled-release device for intravaginal hormone delivery.

Our objective was to develop and validate an electronically controlled hormone-delivery device for reproductive control of cattle. After development and in vitro testing of a prototype device for intravaginal (IVG) hormone release, we aimed to demonstrate the feasibility of inducing luteal regression by automated treatment with PGF2α. The IVG device comprises an outer 3D-printed plastic housing, fluid reservoirs connected to delivery pumps and tubing, a programmable circuit board, and a retention mechanism. For in vitro testing, 4 pumps were programmed to release different target volumes (0.1, 0.2, 0.5, 1.0, and 2.0 mL) in 4 replicates (n = 80). A Bland-Altman plot was constructed to assess the magnitude of disagreement between expected and delivered volumes. Observations fell within acceptable limits of agreement (1.96 standard deviations) >95% of the time, indicating overall good agreement (mean difference = -0.005 mL). To assess in vivo performance of the IVG device, lactating Holstein cows with at least 1 corpus luteum ≥15 mm in diameter were randomly allocated to 1 of 3 treatments: (1) IM-PGF (n = 6): two 25-mg intramuscular doses of PGF2α 24 h apart; (2) DEV-PGF (n = 6): four 25-mg doses of PGF2α released automatically by the IVG device at 10- or 12-h intervals; and (3) DEV-CTL (n = 4): insertion of an empty IVG device (placebo control). Blood samples were collected at 0, 12, 24, 36, 48, and 72 h after treatment. Data were analyzed by ANOVA with repeated measures. All devices (10/10) remained in situ until removed at 48 h. Progesterone (P4) concentrations from 0 to 72 h were affected by treatment, time, and their interaction. Concentrations of P4 did not differ at time 0 but differed from 24 to 72 h: cows in IM-PGF and DEV-PGF had lesser P4 than cows in DEV-CTL. Conversely, P4 did not differ for IM-PGF and DEV-PGF during the experiment. We conclude that the current IVG hormone-releasing device prototype can be programmed to automatically release PGF2α for successful induction of luteal regression in lactating dairy cows.

Portable Resource-Independent Blood-Plasma Separator.

The centrifuge is the gold standard for lab-based sample processing. While extremely efficient and robust, centrifuges are seldom used in the field due to the high-power requirements, size, and operational complexity. The lack of viable alternatives for remote sample collection has crippled the ability for mobile practitioners in human and animal medicine to reliably collect blood samples from their patients. There is no truly resource-independent solution that is able to perform highly efficient blood-plasma separation. Here, we describe our initial efforts in developing the High Efficiency Rapid Magnetic Erythrocyte Separator (H.E.R.M.E.S) sleeve, an apparatus that uses a magnetic bead-based separation assay in a scaled-up form factor to achieve highly efficient separation of erythrocytes from plasma within a short amount of time. The sleeve is easy-to-use, is completely resource independent, and achieves highly efficient separation in sample volumes as large as 1 mL by means of a unique mixing scheme. We demonstrate the performance of the sleeve with human blood samples and compare it against conventional end-over-end mixing.

Implementation and dissemination of an African American popular opinion model to improve lupus awareness: an academic-community partnership.

OBJECTIVE: Lupus is a chronic, autoimmune disease that disproportionately affects African Americans. We adapted the Centers for Disease Control and Prevention's Popular Opinion Leader model to implement an intervention tailored for African American individuals that leverages an academic-community partnership and community-based social networks to disseminate culturally appropriate lupus education. METHODS: Academic rheumatologists, social scientists, and researchers in Boston, MA and Chicago, IL partnered with local lupus support groups, community organizations, and churches in neighborhoods with higher proportions of African Americans to develop curriculum and recruit community leaders with and without lupus (Popular Opinion Leaders; POLs). POLs attended four training sessions focused on lupus education, strategies to educate others, and a review of research methods. POLs disseminated information through their social networks and recorded their impact, which was mapped using a geographic information system framework. RESULTS: We trained 18 POLs in greater Boston and 19 in greater Chicago: 97% were African American, 97% were female; and the mean age was 57 years. Fifty-nine percent of Boston POLs and 68% of Chicago POLs had lupus. POLs at both sites engaged members of their social networks and communities in conversations about lupus, health disparities, and the importance of care. Boston POLs documented 97 encounters with 547 community members reached. Chicago POLs documented 124 encounters with 4083 community members reached. CONCLUSIONS: An adapted, community-based POL model can be used to disseminate lupus education and increase awareness in African American communities. Further research is needed to determine the degree to which this may begin to reduce disparities in access to care and outcomes.

Corticotropin hormone assay interference: A case series.

Measuring the plasma corticotropin (ACTH) concentration is an important step in determining the underlying cause in patients with hypercortisolemia. Interfering substances in immunoassays can lead to erroneous results impacting clinical management. We describe a case series of 12 patients, the majority of whom were being investigated for possible Cushing's syndrome and in whom inconsistencies between the clinical picture and biochemical testing raised concerns of assay interference. ACTH assay interference resulted in falsely elevated ACTH concentrations using the Siemens Immulite assay and consequently led to additional unnecessary testing. Communication between physician and laboratory as well as appropriate investigation (including sample dilution, use of blocking antibodies and testing on an alternate platform) resulted in assay interference identification. Recognition of biochemical results which are clinically discrepant remains an essential step in patient assessment.

Point-of-Care Assessment of Folate Status in Women of Reproductive Age Using a Fluorescence Lateral Flow Assay.

Folate is an essential vitamin to the development of a fetus in early pregnancy. Maternal folate supplementation around the time of conception has been shown to decrease the risk of neural tube defects (NTDs), a class of serious birth defects. The closure of the neural tube before the 28th day after conception necessitates that the folate intake must take place before most women know that they are pregnant. Therefore, screening women of reproductive age for folate status would allow for an improved understanding of the need for supplementation in women who could become pregnant as well as the effectiveness of current supplementation and fortification recommendations. Current folate assessment is limited to labbased assays which require expensive equipment, trained personnel, and are time-intensive. Our point-of-care diagnostic test quantifies levels of folate in human serum with the use of a lateral flow assay and a portable imaging device. We have designed an assay which uses fluorescent particles, folate binding protein, and antibodies to measure serum folate. This test could be used in resource-limited settings, where access to laboratory infrastructure is limited and where knowledge of folate status in women of reproductive age is lacking. By increasing our understanding of folate status around the world, we can improve implementation of folic acid supplementation and fortification and therefore reduce the risk of NTDs.

A Quantitative Point-of-Need Assay for the Assessment of Vitamin D3 Deficiency.

Vitamin D is necessary for the healthy growth and development of bone and muscle. Vitamin D deficiency, which is present in 42% of the US population, is often undiagnosed as symptoms may not manifest for several years and long-term deficiency has been linked to osteoporosis, diabetes and cancer. Currently the majority of vitamin D testing is performed in large-scale commercial laboratories which have high operational costs and long times-to-result. Development of a low-cost point-of-need assay could be transformative to deficiency analysis in limited-resource settings. The best biomarker of vitamin D status, 25hydroxyvitamin D3 (25(OH)D3), however, is particularly challenging to measure in such a format due to complexities involved in sample preparation, including the need to separate the marker from its binding protein. Here we present a rapid diagnostic test for the accurate, quantitative assessment of 25(OH)D3 in finger-stick blood. The assay is accompanied by a smartphone-assisted portable imaging device that can autonomously perform the necessary image processing. To achieve accurate quantification of 25(OH)D3, we also demonstrate a novel elution buffer that separates 25(OH)D3 from its binding protein in situ, eliminating the need for sample preparation. In human trials, the accuracy of our platform is 90.5%.

Real-time in vivo uric acid biosensor system for biophysical monitoring of birds.

Research on birds has long played an important role in ecological investigations, as birds are relatively easily observed, and their high metabolic rates and diurnal habits make them quite evidently responsive to changes in their environments. A mechanistic understanding of such avian responses requires a better understanding of how variation in physiological state conditions avian behavior and integrates the effects of recent environmental changes. There is a great need for sensor systems that will allow free-flying birds to interact with their environment and make unconstrained decisions about their spatial location at the same time that their physiological state is being monitored in real time. We have developed a miniature needle-based enzymatic sensor system suitable for continuous real-time amperometric monitoring of uric acid levels in unconstrained live birds. The sensor system was constructed with Pt/Ir wire and Ag/AgCl paste. Uricase enzyme was immobilized on a 0.7 mm sensing cavity of Nafion/cellulose inner membrane to minimize the influences of background interferents. The sensor response was linear from 0.05 to 0.6 mM uric acid, which spans the normal physiological range for most avian species. We developed a two-electrode potentiostat system that drives the biosensor, reads the output current, and wirelessly transmits the data. In addition to extensive characterization of the sensor and system, we also demonstrate autonomous operation of the system by collecting in vivo extracellular uric acid measurements on a domestic chicken. The results confirm our needle-type sensor system's potential for real-time monitoring of birds' physiological state. Successful application of the sensor in migratory birds could open up a new era of studying both the physiological preparation for migration and the consequences of sustained avian flight.

Visual and non-visual factors associated with patient satisfaction and quality of life in LASIK.

PURPOSE: The aim of this study was to determine how laser in situ keratomileusis (LASIK) affects quality of life (QOL) and to identify factors that may affect satisfaction after LASIK. METHODS: A total of 104 patients with a mean age of 29±6, treated with LASIK for myopia and astigmatism, were enrolled in a prospective study. High (90%) and low (10%) contrast visual acuity (CVA) were measured under photopic and scotopic conditions before surgery and at 3 months later. A multidimensional QOL scale (Institute for Eye Research multidimensional QOL scale), which assesses psychological characteristics, personality traits, cosmesis, frequency, and tolerance to disturbing visual and ocular symptoms, and overall satisfaction with vision correction, was also used. Paired rank tests were used to compare preoperative and postoperative vision and QOL scores. Correlations and a multiple linear regression were used to describe the relationship between CVA, QOL, and satisfaction after LASIK. RESULTS: Significant postoperative changes included increased satisfaction following LASIK (P<0.001), reduced frequency of visual and ocular symptoms (P<0.001), and change in psychological characteristics (P=0.033). The change in satisfaction with LASIK can be predicted by a combination of preoperative satisfaction, postoperative frequency of disturbing visual and ocular symptoms, postoperative mean spherical equivalent, and postoperative scotopic high CVA (R (2)=0.725, P<0.05). CONCLUSIONS: Satisfaction with LASIK is related to visual function, preoperative expectations, psychological characteristics, and uncorrected CVA achieved. An increased sense of subjective well-being, adaptability, and self-efficacy was evident after LASIK. Patients reported a more optimistic attitude to life and increase perceived QOL after surgery.

Effects of solar UV radiation and climate change on biogeochemical cycling: interactions and feedbacks.

Solar UV radiation, climate and other drivers of global change are undergoing significant changes and models forecast that these changes will continue for the remainder of this century. Here we assess the effects of solar UV radiation on biogeochemical cycles and the interactions of these effects with climate change, including feedbacks on climate. Such interactions occur in both terrestrial and aquatic ecosystems. While there is significant uncertainty in the quantification of these effects, they could accelerate the rate of atmospheric CO(2) increase and subsequent climate change beyond current predictions. The effects of predicted changes in climate and solar UV radiation on carbon cycling in terrestrial and aquatic ecosystems are expected to vary significantly between regions. The balance of positive and negative effects on terrestrial carbon cycling remains uncertain, but the interactions between UV radiation and climate change are likely to contribute to decreasing sink strength in many oceanic regions. Interactions between climate and solar UV radiation will affect cycling of elements other than carbon, and so will influence the concentration of greenhouse and ozone-depleting gases. For example, increases in oxygen-deficient regions of the ocean caused by climate change are projected to enhance the emissions of nitrous oxide, an important greenhouse and ozone-depleting gas. Future changes in UV-induced transformations of aquatic and terrestrial contaminants could have both beneficial and adverse effects. Taken in total, it is clear that the future changes in UV radiation coupled with human-caused global change will have large impacts on biogeochemical cycles at local, regional and global scales.

Comparison of silicon photonic crystal resonator designs for optical trapping of nanomaterials.

The use of silicon photonic devices for optical manipulation has recently enabled the direct handling of objects like nucleic acids and nanoparticles that are much smaller than could previously be trapped using traditional laser tweezers. The ability to manipulate even smaller matter however requires the development of photonic structures with even stronger trapping potentials. In this work we investigate theoretically several photonic crystal resonator designs and characterize the achievable trapping stiffness and trapping potential depth (sometimes referred to as the trapping stability). Two effects are shown to increase these trapping parameters: field enhancement in the resonator and strong field containment. We find trapping stiffness as high as 22.3 pN nm(-1) for 100 nm polystyrene beads as well as potential depth of 51,000 k(B)T at T = 300 K, for one Watt of power input to the bus waveguide. Under the same conditions for 70 nm polystyrene beads, we find a stiffness of 69 pN nm(-1) and a potential depth of 177,000 k(B)T. Our calculations suggest that with input power of 10 mW we could trap particles as small as 7.7 nm diameter with a trapping depth of 500 k(B)T. We expect these traps to eventually enable the manipulation of small matter such as single proteins, carbon nanotubes and metallic nanoparticles.

Pre-operative Quality of Life and psychological factors that influence patient decision making in LASIK.

PURPOSE: To assess pre-operative visual function, psychological factors, personality traits and satisfaction in myopic patients seeking laser-assisted in situ keratomileusis (LASIK). METHODS: Eligible patients seeking LASIK (n=183) and successful contact lens wearers (n=23) not interested in LASIK completed the Institute for Eye Research Quality of Life (QOL) Scale. Of the 183 patients seeking LASIK who completed the QOL instrument before LASIK, 30 declined the procedure and 153 underwent LASIK. One hundred and two patients who underwent LASIK attended their 3-month post-operative follow-up appointment and 51 patients failed to present for their post-operative follow-up appointment. Multiple comparisons (One-way Analysis of Variance (ANOVA)) were conducted to determine differences in visual function, psychological factors, personality traits and satisfaction between patient groups. RESULTS: Successful soft contact lens (SCL) wearers reported better functional vision (P=0.001), felt more attractive (P=0.007), had a lower frequency of disturbing visual and ocular symptoms (P=0.027) and higher overall satisfaction with their current optical correction (P<0.001) than patients seeking LASIK. LASIK patients lost to follow-up showed higher self-efficacy, adaptability and well-being than the patients who completed their appointments and those who declined surgery (P<0.05). CONCLUSIONS: Psychological characteristics, the perception of visual and ocular symptoms and satisfaction with the current method of optical correction play an important role in the decision to undergo LASIK. The IER QOL Scale is a valid and reliable instrument able to discriminate between different groups seeking choices for myopic correction. Psychological factors may influence the level of satisfaction with LASIK.

Transient simulation of last deglaciation with a new mechanism for Bolling-Allerod warming.

We conducted the first synchronously coupled atmosphere-ocean general circulation model simulation from the Last Glacial Maximum to the Bølling-Allerød (BA) warming. Our model reproduces several major features of the deglacial climate evolution, suggesting a good agreement in climate sensitivity between the model and observations. In particular, our model simulates the abrupt BA warming as a transient response of the Atlantic meridional overturning circulation (AMOC) to a sudden termination of freshwater discharge to the North Atlantic before the BA. In contrast to previous mechanisms that invoke AMOC multiple equilibrium and Southern Hemisphere climate forcing, we propose that the BA transition is caused by the superposition of climatic responses to the transient CO(2) forcing, the AMOC recovery from Heinrich Event 1, and an AMOC overshoot.

Does the type of CIA policy significantly affect bar and restaurant employment in Minnesota cities?

Clean indoor air (CIA) policies that include free-standing bars and restaurants have been adopted by communities to protect employees in all workplaces from exposure to environmental tobacco smoke, most notably employees working in restaurants and free-standing bars. However, due to the perception of negative economic effects on alcohol-licensed hospitality businesses, partial CIA policies (those that provide an exemption for free-standing bars) have been proposed as a means to reduce the risk of economic effects of comprehensive CIA policies applied to all worksites. Bar and restaurant employment per capita were used to determine if partial CIA policies produced differential economic effects compared to comprehensive CIA policies. Ten cities in the state of Minnesota were studied from 2003-2006. Economic data were drawn from monthly employment in bars and restaurants, and a pooled time-series was completed to evaluate three types of local CIA policies: Comprehensive, partial, or none beyond the state law. Communities with a comprehensive CIA policy had a decrease of 9 employees per 10,000 residents compared with communities with partial CIA policies (p = 0.10). Communities with any type of CIA policy (partial or comprehensive) had an increase of 3 employees per 10,000 residents compared to communities without any CIA policies (p = 0.36). There were no significant differential economic effects by CIA policy type in Minnesota cities. These findings support the adoption of comprehensive CIA policies to provide all employees protection from environmental tobacco smoke exposure.

Silent subtype 3 pituitary adenoma: a clinicopathologic analysis of the Mayo Clinic experience.

BACKGROUND: Macroadenomas represent 50% of pituitary tumours and are often (30%) nonfunctioning. Their immunophenotype suggests differentiation toward a specific pituitary cell line. A substantial proportion of tumours with particularly aggressive behaviour are so called 'silent subtype 3 adenoma'. Its diagnosis requires ultrastructural confirmation. Although once included among silent corticotroph adenomas, this aggressive, morphologically distinctive tumour is now recognized as a major form of plurihormonal adenoma and, in fact, some patients might present with clinical hormonal excess. The cytogenesis and pathobiology of silent subtype 3 adenomas is unsettled. OBJECTIVE: We undertook a systematic clinicopathologic examination of the Mayo Clinic experience with this poorly understood tumour. DESIGN: This retrospective, single institution study found 27 confirmed examples of silent subtype 3 adenoma, a frequency of 0.9% of adenomas. Despite histologic and immunophenotypic variation, their ultrastructural features were diagnostic and the sole basis for case inclusion. RESULTS: The study group was comprised of 16 men (59%) and 11 women (41%); two patients (7%) had definitive diagnosis of multiple endocrine neoplasia type 1 (MEN1). Three tumours (11%) were discovered incidentally. Nine patients each (38%) presented with headaches or visual field loss. Endocrine hyperfunction was noted in eight cases (30%), including GH excess in five (19%) and clinically significant PRL elevation in three (11%). Hypogonadism was noted in 17 cases (63%) and growth arrest in one (4%). All tumours were macroadenomas; 16 (60%) showed radiographic evidence of invasion. Most tumours were plurihormonal, featuring immunoreactivity for PRL (17), GH (15), TSH (16) or ACTH (3); only one lesion was immunonegative. Although a gross total resection was achieved in 19 cases (70%), re-operation for recurrence(s) was required in seven of these (37%). Follow-up (mean, 69 months) showed a high (59%) rate of persistent or recurrent of tumour. Overall, 14 patients (54%) underwent radiotherapy after surgical treatment: three patients (12%) for substantial residual tumour, eight (31%) as adjuvant therapy and three (12%) for tumour regrowth. CONCLUSION: Silent subtype 3 adenoma, a plurihormonal tumour, is rare and aggressive in nature. This adenoma must be considered in the differential of often clinically nonfunctioning but plurihormonal adenomas featuring variable cytologic atypia. Electron microscopy is required for confirmation of the diagnosis. The cytogenesis of silent subtype 3 adenoma remains unsettled.