Pseudopheochromocytoma: an Uncommon Cause of Severe Hypertension.

PURPOSE OF REVIEW: Pseudopheochromocytoma or paroxysmal hypertension is an underrecognized condition that requires a thorough investigation of secondary causes of hypertension. In this review, we aim to provide an overview of pathogenesis, clinical manifestations, biochemical evaluation, and potential therapeutic options to manage patients with pseudopheochromocytoma. RECENT FINDINGS: The pathogenesis of this condition has not been completely elucidated but certain patients show overactivity of the sympathetic nervous system and present with elevated epinephrine and dopamine levels. Workup should include a proper evaluation of blood pressure in distinct clinical scenarios, including ambulatory blood pressure monitoring. Management should be focused on treatment of acute hypertensive episodes and prevention of paroxysms. Treatment of patients with pseudopheochromocytoma should be individualized. Psychopharmacotherapy and psychotherapeutic interventions play an important role in controlling patients' symptoms.

Stability Prediction for Mutations in the Cytosolic Domains of Cystic Fibrosis Transmembrane Conductance Regulator.

Cystic Fibrosis (CF) is caused by mutations to the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) chloride channel. CFTR is composed of two membrane spanning domains, two cytosolic nucleotide-binding domains (NBD1 and NBD2) and a largely unstructured R-domain. Multiple CF-causing mutations reside in the NBDs and some are known to compromise the stability of these domains. The ability to predict the effect of mutations on the stability of the cytosolic domains of CFTR and to shed light on the mechanisms by which they exert their effect is therefore important in CF research. With this in mind, we have predicted the effect on domain stability of 59 mutations in NBD1 and NBD2 using 15 different algorithms and evaluated their performances via comparison to experimental data using several metrics including the correct classification rate (CCR), and the squared Pearson correlation (R2) and Spearman's correlation (ρ) calculated between the experimental ΔTm values and the computationally predicted ΔΔG values. Overall, the best results were obtained with FoldX and Rosetta. For NBD1 (35 mutations), FoldX provided R2 and ρ values of 0.64 and -0.71, respectively, with an 86% correct classification rate (CCR). For NBD2 (24 mutations), FoldX R2, ρ, and CCR were 0.51, -0.73, and 75%, respectively. Application of the Rosetta high-resolution protocol (Rosetta_hrp) to NBD1 yielded R2, ρ, and CCR of 0.64, -0.75, and 69%, respectively, and for NBD2 yielded R2, ρ, and CCR of 0.29, -0.27, and 50%, respectively. The corresponding numbers for the Rosetta's low-resolution protocol (Rosetta_lrp) were R2 = 0.47, ρ = -0.69, and CCR = 69% for NBD1 and R2 = 0.27, ρ = -0.24, and CCR = 63% for NBD2. For NBD1, both algorithms suggest that destabilizing mutations suffer from destabilizing vdW clashes, whereas stabilizing mutations benefit from favorable H-bond interactions. Two triple consensus approaches based on FoldX, Rosetta_lpr, and Rosetta_hpr were attempted using either "majority-voting" or "all-voting". The all-voting consensus outperformed the individual predictors, albeit on a smaller data set. In summary, our results suggest that the effect of mutations on the stability of CFTR's NBDs could be largely predicted. Since NBDs are common to all ABC transporters, these results may find use in predicting the effect and mechanism of the action of multiple disease-causing mutations in other proteins.

Randomized Controlled Trial of Bovine Lactoferrin for Prevention of Sepsis and Neurodevelopment Impairment in Infants Weighing Less Than 2000 Grams.

OBJECTIVES: To determine the effect of bovine lactoferrin on prevention of late-onset sepsis (LOS) and neurodevelopment delay. STUDY DESIGN: Randomized, double-blind, controlled trial in neonates with a birth weight of 500-2000 g in 3 neonatal units in Lima, Peru, comparing bovine lactoferrin 200 mg/kg/day with placebo administered for 8 weeks. The primary outcome was the first episode of culture-proven LOS or sepsis-associated death. Neurodevelopment delay was assessed by the Mullen Scales at 24 months corrected age. RESULTS: Of the 414 infants enrolled, 209 received bovine lactoferrin and 205 received placebo. LOS or sepsis-associated death occurred in 22 infants (10.5%) in the bovine lactoferrin group vs 30 (14.6%) in the placebo group; there was no difference after adjusting for hospital and birth weight; hazard ratio 0.73 (95% CI, 0.42-1.26). For infants with birth weights of <1500 g the hazard ratio was 0.69 (95% CI, 0.39-1.25). The mean age-adjusted normalized Mullen composite score at 24 months was 83.3 ± 13.6 in the bovine lactoferrin group vs 82.6 ± 13.1 in the placebo group. Growth outcomes and rehospitalization rates during the 2-year follow-up were similar in both groups, except for significantly less bronchiolitis in the bovine lactoferrin group (rate ratio, 0.34; 95% CI, 0.14-0.86). CONCLUSIONS: Supplementation with bovine lactoferrin did not decrease the incidence of sepsis in infants with birth weights of <2000 g. Growth and neurodevelopment outcomes at 24 months of age were similar. Neonatal bovine lactoferrin supplementation had no adverse effects. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01525316.

Ligand binding to a remote site thermodynamically corrects the F508del mutation in the human cystic fibrosis transmembrane conductance regulator.

Many disease-causing mutations impair protein stability. Here, we explore a thermodynamic strategy to correct the disease-causing F508del mutation in the human cystic fibrosis transmembrane conductance regulator (hCFTR). F508del destabilizes nucleotide-binding domain 1 (hNBD1) in hCFTR relative to an aggregation-prone intermediate. We developed a fluorescence self-quenching assay for compounds that prevent aggregation of hNBD1 by stabilizing its native conformation. Unexpectedly, we found that dTTP and nucleotide analogs with exocyclic methyl groups bind to hNBD1 more strongly than ATP and preserve electrophysiological function of full-length F508del-hCFTR channels at temperatures up to 37 °C. Furthermore, nucleotides that increase open-channel probability, which reflects stabilization of an interdomain interface to hNBD1, thermally protect full-length F508del-hCFTR even when they do not stabilize isolated hNBD1. Therefore, stabilization of hNBD1 itself or of one of its interdomain interfaces by a small molecule indirectly offsets the destabilizing effect of the F508del mutation on full-length hCFTR. These results indicate that high-affinity binding of a small molecule to a remote site can correct a disease-causing mutation. We propose that the strategies described here should be applicable to identifying small molecules to help manage other human diseases caused by mutations that destabilize native protein conformation.

Expertise in Head and Neck Cutaneous Reconstructive Surgery.

BACKGROUND: The management of skin cancers has evolved with the development of Mohs micrographic surgery and a greater emphasis on surgical training within dermatology. It is unclear whether these changes have translated into innovations and contributions to the reconstructive literature. OBJECTIVE: To assess contributions from each medical specialty to the cutaneous head and neck oncologic reconstructive literature. METHODS: The authors conducted a systematic review of the head and neck reconstructive literature from 2000 through 2015 based on a priori search terms relating to suture technique, linear closure, advancement, rotation, transposition and interpolation flaps, and identified the specialty of the senior authors. RESULTS: The authors identified 74,871 articles, of which 1,319 were relevant. Under suture technique articles, the senior authors were primarily dermatologists (58.2%) and plastic surgeons (20.3%). Under linear closure, the authors were dermatologists (48.1%), plastic surgeons (22.2%), and otolaryngologists (20.4%). Under advancement and rotation flaps, the senior authors were plastic surgeons (40.5%, 38.9%), dermatologists (38.1%, 34.2%), and otolaryngologists (14.4%, 21.6%). Under transposition and interpolation flaps, the senior authors were plastic surgeons (47.3%, 39.4%), dermatologists (32.3%, 27.0%), and otolaryngologists (15.3%, 23.4%). CONCLUSION: The primary specialties contributing to the cutaneous head and neck reconstructive literature are plastic surgery, dermatology, and otolaryngology.

Stabilization of a nucleotide-binding domain of the cystic fibrosis transmembrane conductance regulator yields insight into disease-causing mutations.

Characterization of the second nucleotide-binding domain (NBD2) of the cystic fibrosis transmembrane conductance regulator (CFTR) has lagged behind research into the NBD1 domain, in part because NBD1 contains the F508del mutation, which is the dominant cause of cystic fibrosis. Research on NBD2 has also been hampered by the overall instability of the domain and the difficulty of producing reagents. Nonetheless, multiple disease-causing mutations reside in NBD2, and the domain is critical for CFTR function, because channel gating involves NBD1/NBD2 dimerization, and NBD2 contains the catalytically active ATPase site in CFTR. Recognizing the paucity of structural and biophysical data on NBD2, here we have defined a bioinformatics-based method for manually identifying stabilizing substitutions in NBD2, and we used an iterative process of screening single substitutions against thermal melting points to both produce minimally mutated stable constructs and individually characterize mutations. We present a range of stable constructs with minimal mutations to help inform further research on NBD2. We have used this stabilized background to study the effects of NBD2 mutations identified in cystic fibrosis (CF) patients, demonstrating that mutants such as N1303K and G1349D are characterized by lower stability, as shown previously for some NBD1 mutations, suggesting a potential role for NBD2 instability in the pathology of CF.

Structural stability of purified human CFTR is systematically improved by mutations in nucleotide binding domain 1.

The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is an ABC transporter containing two transmembrane domains forming a chloride ion channel, and two nucleotide binding domains (NBD1 and NBD2). CFTR has presented a formidable challenge to obtain monodisperse, biophysically stable protein. Here we report a comprehensive study comparing effects of single and multiple NBD1 mutations on stability of both the NBD1 domain alone and on purified full length human CFTR. Single mutations S492P, A534P, I539T acted additively, and when combined with M470V, S495P, and R555K cumulatively yielded an NBD1 with highly improved structural stability. Strategic combinations of these mutations strongly stabilized the domain to attain a calorimetric Tm > 70 °C. Replica exchange molecular dynamics simulations on the most stable 6SS-NBD1 variant implicated fluctuations, electrostatic interactions and side chain packing as potential contributors to improved stability. Progressive stabilization of NBD1 directly correlated with enhanced structural stability of full-length CFTR protein. Thermal unfolding of the stabilized CFTR mutants, monitored by changes in intrinsic fluorescence, demonstrated that Tm could be shifted as high as 67.4 °C in 6SS-CFTR, more than 20 °C higher than wild-type. H1402S, an NBD2 mutation, conferred CFTR with additional thermal stability, possibly by stabilizing an NBD-dimerized conformation. CFTR variants with NBD1-stabilizing mutations were expressed at the cell surface in mammalian cells, exhibited ATPase and channel activity, and retained these functions to higher temperatures. The capability to produce enzymatically active CFTR with improved structural stability amenable to biophysical and structural studies will advance mechanistic investigations and future cystic fibrosis drug development.

Direct Binding of the Corrector VX-809 to Human CFTR NBD1: Evidence of an Allosteric Coupling between the Binding Site and the NBD1:CL4 Interface.

Understanding the mechanism of action of modulator compounds for the cystic fibrosis transmembrane conductance regulator (CFTR) is key for the optimization of therapeutics as well as obtaining insights into the molecular mechanisms of CFTR function. We demonstrate the direct binding of VX-809 to the first nucleotide-binding domain (NBD1) of human CFTR. Disruption of the interaction between C-terminal helices and the NBD1 core upon VX-809 binding is observed from chemical shift changes in the NMR spectra of residues in the helices and on the surface of ß-strands S3, S9, and S10. Binding to VX-809 leads to a significant negative shift in NBD1 thermal melting temperature (Tm), pointing to direct VX-809 interaction shifting the NBD1 conformational equilibrium. An inter-residue correlation analysis of the chemical shift changes provides evidence of allosteric coupling between the direct binding site and the NBD1:CL4 interface, thus enabling effects on the interface in the absence of direct binding in that location. These NMR binding data and the negative Tm shifts are very similar to those previously reported by us for binding of the dual corrector-potentiator CFFT-001 to NBD1 (Hudson et al., 2012), suggesting that the two compounds may share some aspects of their mechanisms of action. Although previous studies have shown an important role for VX-809 in modulating the conformation of the first membrane spanning domain (Aleksandrov et al., 2012; Ren et al., 2013), this additional mode of VX-809 binding provides insight into conformational dynamics and allostery within CFTR.

Interactions and cooperativity between P-glycoprotein structural domains determined by thermal unfolding provides insights into its solution structure and function.

Structural changes in mouse P-glycoprotein (Pgp) induced by thermal unfolding were studied by differential scanning calorimetry (DSC), circular dichroism and fluorescence spectroscopy to gain insight into the solution conformation(s) of this ABC transporter that may not be apparent from current crystal structures. DSC of reconstituted Pgp showed two thermal unfolding transitions in the absence of MgATP, suggesting that each transition involved the cooperative unfolding of two or more interacting structural domains. A low calorimetric unfolding enthalpy and minimal structural changes were observed, which are hallmarks of the thermal unfolding of α-helical membrane proteins, because generally only the extramembranous regions undergo significant unfolding. Nucleotide binding increased the unfolding temperature of both transitions to the same extent, suggesting that one nucleotide binding domain (NBD) unfolds with each transition. Combined with the results from the two isolated NBDs, we propose that each DSC transition represents the cooperative unfolding of one NBD and the two contacting intracellular loops. Further, the presence of two transitions in both apo and MgATP bound wild-type Pgp suggests the NBD-dimeric conformation is transient, and that Pgp resides predominantly in the crystallographically observed inward-facing conformation with NBDs separated, even under conditions supporting continuous MgATP hydrolysis. In contrast, DSC of the vanadate-trapped MgADP·Pgp complex and the MgATP-bound catalytically inactive mutant, E552A/E1197A, show an additional transition at much higher temperature, corresponding to the unfolding of the nucleotide-trapped NBD-dimeric outward-facing conformation. The collective results indicate a strong preference for an NBD dissociated, inward-facing conformation of Pgp.

Factors affecting lactoferrin concentration in human milk: how much do we know?

Lactoferrin (LF) is a breast milk glycoprotein with antimicrobial and anti-inflammatory effects. Its beneficial properties in infants, especially in those born preterm, are currently being studied in clinical trials. However, the maternal and nursing infant factors that may affect LF concentration in breast milk are still not clear. We conducted a systematic review to investigate the factors that may affect the concentration of LF in breast milk. We used a 2-step approach to identify the eligible studies according to inclusion/exclusion criteria, and to determine which studies would be considered. We included 70 qualified articles from 29 countries with publication dates ranging from 1976 to 2015. We described the correlation between LF concentration in breast milk and lactation stage; 10 maternal factors, such as race, parity, among others; and 2 infant factors: infections and prematurity. Colostrum has the highest LF levels, but they decrease with days postpartum. No other factor has been consistently associated with LF concentration. A major limitation of the majority of the published studies is the small sample size and the different methods used to measure LF concentration. Therefore, there is a need for large, multicenter studies with standardized study design, sample collection, and LF measurement methods to identify clinically significant factors associated with LF expression in breast milk, which will help promote exclusive breastfeeding in preterm infants.

Functionality of Patients 75 Years and Older Undergoing Mohs Micrographic Surgery: A Multicenter Study.

BACKGROUND: Mohs surgery is indisputably a highly effective treatment for nonmelanoma skin cancers. In the current health care environment, physicians are challenged to provide high quality, efficacious care in a manner that is mindful of the patient's general health and well-being. We have used a functional assessment to evaluate older patients who present for Mohs surgery. OBJECTIVE: The purpose of this study is to categorize the functional status, using the Karnofsky Performance Status (KPS) Scale, of patients 75 years and older undergoing Mohs surgery of a nonmelanoma skin cancer and to identify distinguishing characteristics of lower functioning patients. METHODS: Patients 75 years and older undergoing Mohs surgery for nonmelanoma skin cancer at 8 separate geographically diverse sites were included. Patient and tumor characteristics were recorded. Physicians scored subjects on the KPS scale and administered a questionnaire to categorize the symptoms and impact of their skin cancer. RESULTS: A total of 291 subjects completed the study. The average KPS score was 90.1. 93.1% of our subjects had a KPS score of ≥70. Subjects with a KPS score <70 were more likely to be older with larger symptomatic tumors. CONCLUSION: The vast majority of patients 75 years and older undergoing Mohs surgery are highly functioning. Lower functioning patients are older with larger symptomatic tumors that negatively impact their lives.

Effects of culture conditions on the size, morphology and wet density of spores of Bacillus cereus 569 and Bacillus megaterium QM B1551.

The influence of variable culture conditions on the size and wet density of spores of Bacillus cereus and Bacillus megaterium were examined in this work. Culture temperature and initial pH was shown to have a significant impact on the size of both species, with increasingly alkaline culture media and elevated culture temperatures resulting in spores that were, on average, up to 25% reduced in volume. Increasing concentrations of inorganic salts in sporulation media exerted differing effects on each species; whereas a fivefold increase in the concentration of all salts resulted in only minor differences to the dimensions of B. cereus spores, B. megaterium spores became more elongated, displaying an average increase in volume of almost 30%. Similarly, as the spore elongated to yield aspect ratios larger than 1·4, their shape changed from typical prolate spheroids to cylinders with hemispherical ends. In contrast with previous studies, culture conditions employed in this study exerted no discernible impact on the wet density of B. cereus or B. megaterium spores. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacterial spores of the genera Bacillus and Clostridium represent nature's most durable cells in terms of their extreme resistance to a variety of deleterious environments. As a result, they are of concern in the food processing, healthcare and other sectors, and are of increasing biotechnological interest. Improved understanding of variance in spore size, morphology and density may aid the development of certain spore-associated applications (e.g. spore surface display) while contributing to active areas of research such as spore adhesion and resistance to heat.

Versatility of the O-Z Flap in the Reconstruction of Facial Defects.

BACKGROUND: The O-Z flap has traditionally been used for surgical defects adjacent to critical anatomic structures requiring a repair option that minimizes distortion and functional impairment. However, another advantage of the O-Z flap is that it is tissue conservative, particularly in comparison to primary closure. In fact, the design simply takes the Burow's triangles that would be discarded and rotates them inward. OBJECTIVE: The purpose of this work is to detail the type of post-Mohs defects, which might benefit from consideration of the O-Z flap with emphasis on tissue conservation and restoration of contour to the surgical site. Furthermore, the authors wish to describe unique considerations in each location and methods to appropriately plan the O-Z flap in each circumstance. METHODS AND MATERIALS: The authors reviewed all flaps classified as O-Z in their tumor registry. The approximate size of the defect reconstructed, complications, and long-term outcomes were recorded. RESULTS: O-Z flap implementation is described in detail for repair of defects located at the lateral nasal tip, nose-cheek junction, medial canthus, and mid-cheek. CONCLUSION: The O-Z flap can be effectively used to repair defects located at the lateral nasal tip, nose-cheek junction, medial canthus, and mid-cheek. It is a mechanically simple flap with predictable tension vectors, which can be specifically oriented to protect the free margin.

The Analog Revolution and Its On-Going Role in Modern Analytical Measurements.

The electronic revolution in analytical instrumentation began when we first exceeded the two-digit resolution of panel meters and chart recorders and then took the first steps into automated control. It started with the first uses of operational amplifiers (op amps) in the analog domain 20 years before the digital computer entered the analytical lab. Their application greatly increased both accuracy and precision in chemical measurement and they provided an elegant means for the electronic control of experimental quantities. Later, laboratory and personal computers provided an unlimited readout resolution and enabled programmable control of instrument parameters as well as storage and computation of acquired data. However, digital computers did not replace the op amp's critical role of converting the analog sensor's output to a robust and accurate voltage. Rather it added a new role: converting that voltage into a number. These analog operations are generally the limiting portions of our computerized instrumentation systems. Operational amplifier performance in gain, input current and resistance, offset voltage, and rise time have improved by a remarkable 3-4 orders of magnitude since their first implementations. Each 10-fold improvement has opened the doors for the development of new techniques in all areas of chemical analysis. Along with some interesting history, the multiple roles op amps play in modern instrumentation are described along with a number of examples of new areas of analysis that have been enabled by their improvements.

Suture Products and Techniques: What to Use, Where, and Why.

BACKGROUND: There are an increasing number of wound closure materials and suturing techniques described in the dermatologic and surgery literature. A dermatologic surgeon's familiarity with these materials and techniques is important to supplement his or her already established practices and improve surgical outcomes. OBJECTIVE: To perform a thorough literature review of wound closure materials (sutures, tissue adhesives, surgical tape, and staples) and suturing techniques and to outline how and when to use them. MATERIALS AND METHODS: A literature review was conducted using PubMed and other online search engines. Keywords searched included suture, tissue adhesive, tissue glue, surgical tape, staples, dermatologic suturing, and suturing techniques. RESULTS: Numerous articles outline the utility of various sutures, surgical adhesives, surgical tape, and staples in dermatologic surgery. In addition, there are various articles describing classic and novel suturing techniques along with their specific uses in cutaneous surgery. CONCLUSION: Numerous factors must be considered when choosing a wound closure material and suturing technique. These include wound tension, desire for wound edge eversion/inversion, desired hemostasis, repair type, patient's ability to care for the wound and return for suture removal, skin integrity, and wound location. Careful consideration of these factors and proper execution of suturing techniques can lead to excellent cosmetic results.

Zoom-TOFMS: addition of a constant-momentum-acceleration "zoom" mode to time-of-flight mass spectrometry.

In this study, we demonstrate the performance of a new mass spectrometry concept called zoom time-of-flight mass spectrometry (zoom-TOFMS). In our zoom-TOFMS instrument, we combine two complementary types of TOFMS: conventional, constant-energy acceleration (CEA) TOFMS and constant-momentum acceleration (CMA) TOFMS to provide complete mass-spectral coverage as well as enhanced resolution and duty factor for a narrow, targeted mass region, respectively. Alternation between CEA- and CMA-TOFMS requires only that electrostatic instrument settings (i.e., reflectron and ion optics) and ion acceleration conditions be changed. The prototype zoom-TOFMS instrument has orthogonal-acceleration geometry, a total field-free distance of 43 cm, and a direct-current glow-discharge ionization source. Experimental results demonstrate that the CMA-TOFMS "zoom" mode offers resolution enhancement of 1.6 times over single-stage acceleration CEA-TOFMS. For the atomic mass range studied here, the maximum resolving power at full-width half-maximum observed for CEA-TOFMS was 1,610 and for CMA-TOFMS the maximum was 2,550. No difference in signal-to-noise (S/N) ratio was observed between the operating modes of zoom-TOFMS when both were operated at equivalent repetition rates. For a 10-kHz repetition rate, S/N values for CEA-TOFMS varied from 45 to 990 and from 67 to 10,000 for CMA-TOFMS. This resolution improvement is the result of a linear TOF-to-mass scale and the energy-focusing capability of CMA-TOFMS. Use of CMA also allows ions outside a given m/z range to be rejected by simple ion-energy barriers to provide a substantial improvement in duty factor.

Lactoferrin for prevention of neonatal sepsis.

Preterm neonates are at risk to acquire infections. In addition to the high mortality associated with sepsis, these patients are at risk for long-term disabilities, particularly neurodevelopment impairment. Several interventions have been evaluated to reduce rates of infections in neonates but have not proven efficacy. Lactoferrin (LF), a milk glycoprotein with anti-inflammatory, immunomodulatory and anti-microbial properties, has the potential to prevent infections in young children. We performed a review of current and ongoing clinical trials of LF for prevention of neonatal sepsis, and found eleven registered clinical trials that include more than 6,000 subjects. Few of these trials have finished; despite their small sample size, the preliminary results show a trend towards a positive protective effect of LF on neonatal infections. Larger trials are underway to confirm the findings of these initial studies. This information will help to define LF's role in clinical settings and, if proven effective, would profoundly affect the treatment of low birth weight neonates as a cost-effective intervention worldwide.

Reassessment of Plurihormonal Pituitary Adenomas/PitNETs.

Plurihormonal pituitary adenomas/neuroendocrine tumors express multiple pituitary hormones and/or transcription factors, as determined by immunohistochemistry (IHC). Three types exist based on Endocrine WHO 2022 classification: mature plurihormonal PIT1 (pituitary-specific POU-class homeodomain factor-1), immature PIT1-lineage tumors, and a third type with unusual combinations of pituitary hormones and/or transcription factors. However, since then, "somatogonatotroph"/"multilineage" tumors with PIT1/SF1 (steroidogenic factor 1) co-expression have been described, possibly confounding this classification. We performed a database search, from 2018 to 2023, to identify and reclassify tumors, correlating with neuroimaging and endocrinological features at presentation. We identified 22 cases: M 9:F 13, mean age at surgery 51±16 years. The most common symptoms at initial presentation were headaches and/or vision changes (6/22) and acromegaly (5/22). All tumors were macroadenomas, mean diameter of 25±17mm; 11/22 (50%) had cavernous sinus invasion. More than 70% of tumors clinically secreted at least 1 hormone, and 27% tumors secreted at least 2 different hormones. Four patients underwent >1 surgical intervention. Reclassification by IHC yielded almost exclusively 2 types: immature PIT1-lineage (9/22) and "somatogonadotroph"/"multilineage tumors" with PIT1/SF1 co-expression (12/22), the latter replacing mature plurihormonal tumors. One true unusual plurihormonal tumor was identified. The extent of growth hormone, prolactin, thyroid stimulating hormone, PIT1, and SF1 IHC was variable, but immunopositivity for follicle-stimulating hormone and/or luteinizing hormone was nearly confined to co-expressors, distinguishing these from immature PIT1-lineage tumors. In conclusion, tumor size, invasiveness, and endocrinopathies do not distinguish PIT1/SF1 co-expressing tumors from immature PIT1-lineage tumors preoperatively; only full IHC pituitary workup allows distinction.

Clinical Outcomes Following SARS-CoV-2 Infection in Pediatric Cystic Fibrosis Patients.

Background Cystic fibrosis (CF) is a genetic disorder of the cystic fibrosis transmembrane conductance regulator chloride channel that leads to impaired mucus clearance in the airways, which leads to deteriorations in lung function and chronic respiratory infection. These effects of CF contribute to the hypothesis that patients with CF may be at increased risk of complications when they catch coronavirus disease 2019 (COVID-19), which swept the world in a global pandemic starting in 2019. Overall, however, the role of CF in COVID-19 has not been well studied, particularly in pediatric patients. Methods In this retrospective review, pediatric patients with CF who contracted COVID-19 (3/1/2020-3/1/2023) (N=69) were compared to two equally sized control cohorts of patients with only CF or COVID-19 matched based on demographics and clinical baselines. Occurrences of adverse outcomes (emergency room visits, hospitalizations, CF pulmonary exacerbations, etc.) were assessed for each subject. The mean percentage of predicted forced expiratory volume in 1 second (FEV1%pred) was also assessed for CF patients. Fisher's exact test assessed differences between the proportions of subjects who experienced each outcome. Independent two-variable t-testing assessed mean FEV1%pred differences. Analysis was conducted using IBM SPSS Statistics for Windows, Version 29 (Released 2023; IBM Corp., Armonk, New York, United States) with a significance α=0.05. Ad hoc power analysis was conducted using G*Power v3.1. Results Overall, CF/COVID subjects fared similarly to control groups without either CF or COVID-19 history, including among subgroups stratified based on baseline respiratory function, P. aeruginosa colonization status, and COVID-19 vaccination status. One notable finding was that CF/COVID subjects experienced significantly fewer pulmonary exacerbations compared to CF-only subjects (p=0.004).  Conclusion In conclusion, pediatric CF patients performed similarly to their peers without CF with regard to COVID-19 and generally did not demonstrate significant deteriorations in pulmonary function following infection. Lower incidence of pulmonary exacerbations in CF/COVID subjects could be explained by stringent monitoring by parents, quarantine, or close pulmonology follow-up. These findings will provide guidance on management and care for pediatric CF patients with COVID-19.