Robustness of mitochondrial biogenesis and respiration explain aerobic glycolysis.

A long-standing observation is that in fast-growing cells, respiration rate declines with increasing growth rate and is compensated by an increase in fermentation, despite respiration being more efficient than fermentation. This apparent preference for fermentation even in the presence of oxygen is known as aerobic glycolysis, and occurs in bacteria, yeast, and cancer cells. Considerable work has focused on understanding the potential benefits that might justify this seemingly wasteful metabolic strategy, but its mechanistic basis remains unclear. Here we show that aerobic glycolysis results from the saturation of mitochondrial respiration and the decoupling of mitochondrial biogenesis from the production of other cellular components. Respiration rate is insensitive to acute perturbations of cellular energetic demands or nutrient supplies, and is explained simply by the amount of mitochondria per cell. Mitochondria accumulate at a nearly constant rate across different growth conditions, resulting in mitochondrial amount being largely determined by cell division time. In contrast, glucose uptake rate is not saturated, and is accurately predicted by the abundances and affinities of glucose transporters. Combining these models of glucose uptake and respiration provides a quantitative, mechanistic explanation for aerobic glycolysis. The robustness of specific respiration rate and mitochondrial biogenesis, paired with the flexibility of other bioenergetic and biosynthetic fluxes, may play a broad role in shaping eukaryotic cell metabolism.

Maternal transmission as a microbial symbiont sieve, and the absence of lactation in male mammals.

Gut microbiomes of mammals carry a complex symbiotic assemblage of microorganisms. Feeding newborn infants milk from the mammary gland allows vertical transmission of the parental milk microbiome to the offspring's gut microbiome. This has benefits, but also has hazards for the host population. Using mathematical models, we demonstrate that biparental vertical transmission enables deleterious microbial elements to invade host populations. In contrast, uniparental vertical transmission acts as a sieve, preventing these invasions. Moreover, we show that deleterious symbionts generate selection on host modifier genes that keep uniparental transmission in place. Since microbial transmission occurs during birth in placental mammals, subsequent transmission of the milk microbiome needs to be maternal to avoid the spread of deleterious elements. This paper therefore argues that viviparity and the hazards from biparental transmission of the milk microbiome, together generate selection against male lactation in placental mammals.

Difficulties in using land use pressure and soil quality indicators to predict water quality.

Intensive agriculture can impair river water quality. Soil quality monitoring has been used to measure the effect of land use intensification on water quality at a point and field scales but not at the catchment scale. Other farm scale land use pressures, like stocking rate and the value of land, which relate to land use intensity are now publicly available, nationally. We therefore tested whether point scale soil quality measures, together with newly available farm scale land use pressures (land valuation and stocking rate) and existing catchment and climatic characteristics could help predict the behaviour of water quality data across 192 catchments in New Zealand. We used a generalised additive model to make predictions of the change in nitrogen fractions (r2 = 0.65-0.71), phosphorus fractions (r2 = 0.51-0.70), clarity and turbidity (r2 = 0.42-0.46), and E. coli (r2 = 0.35) over 15 years. The state and trend of water quality was strongly related to a refined farm scale land use classification, and to catchment and climatic characteristics (e.g. slope, elevation, and rainfall). Relationships with point scale soil quality measures and the land use pressures were weak. The weak relationship with land use pressures may be caused by using a single snapshot in time (2022), which cannot account for lag times in water quality response but leaves room for additional temporal data to improve predictive power. The weak relationship to soil quality measures was probably caused by limited data points (n = 667 sites) that were unrepresentative of land use, and areas of catchment subject to processes like runoff or leaching. While national soil quality measures might be useful for evaluating environmental risk at the field or farm scale, without a large increase in sampling, they were not relevant at the catchment scale. Additional analyses should be performed to determine how many samples would be needed to detect a change using an environmentally focused soil test that can guide water quality management.

A parallel glycolysis provides a selective advantage through rapid growth acceleration.

Glycolysis is a universal metabolic process that breaks down glucose to produce adenosine triphosphate (ATP) and biomass precursors. The Entner-Doudoroff (ED) pathway is a glycolytic pathway that parallels textbook glycolysis but yields half as much ATP. Accordingly, in organisms that possess both glycolytic pathways (for example, Escherichia coli), its raison d'être remains a mystery. In this study, we found that the ED pathway provides a selective advantage during growth acceleration. Upon carbon and nitrogen upshifts, E. coli accelerates growth faster with than without the ED pathway. Concurrent isotope tracing reveals that the ED pathway flux increases faster than that of textbook glycolysis. We attribute the fast response time of the ED pathway to its strong thermodynamic driving force and streamlining of glucose import. Intermittent nutrient supply manifests the evolutionary advantage of the parallel glycolysis; thus, the dynamic nature of an ostensibly redundant pathway's role in promoting rapid adaptation constitutes a metabolic design principle.

Atlas of fetal metabolism during mid-to-late gestation and diabetic pregnancy.

Mounting evidence suggests metabolism instructs stem cell fate decisions. However, how fetal metabolism changes during development and how altered maternal metabolism shapes fetal metabolism remain unexplored. We present a descriptive atlas of in vivo fetal murine metabolism during mid-to-late gestation in normal and diabetic pregnancy. Using 13C-glucose and liquid chromatography-mass spectrometry (LC-MS), we profiled the metabolism of fetal brains, hearts, livers, and placentas harvested from pregnant dams between embryonic days (E)10.5 and 18.5. Our analysis revealed metabolic features specific to a hyperglycemic environment and signatures that may denote developmental transitions during euglycemic development. We observed sorbitol accumulation in fetal tissues and altered neurotransmitter levels in fetal brains isolated from hyperglycemic dams. Tracing 13C-glucose revealed disparate fetal nutrient sourcing depending on maternal glycemic states. Regardless of glycemic state, histidine-derived metabolites accumulated in late-stage fetal tissues. Our rich dataset presents a comprehensive overview of in vivo fetal tissue metabolism and alterations due to maternal hyperglycemia.

Nanoparticle Concentration in Surgical Plume During Tonsillectomy: A Comparison of Four Techniques.

OBJECTIVE: Surgical plume has known potential occupational health hazards. This study compares nanoparticle concentrations in surgical plumes generated between different pediatric tonsillectomy surgical techniques and assesses the efficacy of mitigation measures. METHODS: This is a cross-sectional study performed at a tertiary care academic center. Extracapsular or intracapsular tonsillectomy was performed in 60 patients using four techniques and in 10 additional patients using mitigation measures. Two nanoparticle counters were used to measure particulate concentrations: CPC™ and DiSCmini™. Tonsillectomy techniques included: (1) microdebrider (MD), (2) Bovie with manual suctioning by an assistant (B), (3) Bovie with built-in smoke evacuation system (BS), and (4) Coblator™ (CB). An additional Yankauer suction was used in the mitigation groups (BSY) and (CBY). Comparative analysis was performed using one-way ANOVA on ranks and pairwise comparisons between the groups. RESULTS: The mean concentrations (particles/cm3) and coefficient of variants for the DiSCmini particulate counter were MD: 5140 (1.6), B: 30700 (1.5), BS: 25001 (0.8), CB: 54814 (1.7), CBY: 2395 (1.3) and BSY: 11552 (1.0). Mean concentrations for the CPC particulate counter were MD: 1223 (1.4), B: 3405 (0.7), BS: 5002 (0.9), CB: 13273 (1.0), CBY: 1048 (1.2) and BSY: 3046 (0.6). The lowest mean concentrations were noted in cases using MD and the highest in cases using CB. However, after mitigation, CBY had the lowest overall levels. CONCLUSION: Tonsillectomy technique does impact the levels of nanoparticles emitted within the surgical plume, which may present an occupational hazard for operating room personnel. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:2444-2448, 2024.

Intraoperative Parathyroid Hormone Monitoring In Normohormonal Primary Hyperparathyroidism: How Low Do You Go?

OBJECTIVE: The primary goal of this study was to determine in patients with normohormonal primary hyperparathyroidism (NHHPT) what percent reduction in post-excision intraoperative parathyroid hormone (IOPTH) from baseline would yield a rate of cure comparable to that in patients with classical primary hyperparathyroidism (PHPT). METHODS: This is a retrospective cohort study of patients who underwent parathyroidectomy between July 2013 and February 2020. Demographic data, preoperative, intraoperative, and postoperative metrics were collected. Patients with NHHPT were compared to those with classical PHPT. Subgroup analyses were performed. RESULTS: Of the 496 patients included in the study, 66 (13.3%) were of the normohormonal variant based on preoperative intact parathyroid hormone (PTH) levels and 28 (5.6%) based on baseline IOPTH levels. The cure rates in the two normohormonal groups were not significantly different from their classical counterparts (98.4% and 100.0% vs. 97.1%, p = 1.000). The median percent decline in post-excision IOPTH from baseline that achieved cure in the normohormonal groups were 82.6% and 80.4% compared to their respective controls at 87.3%, p = 0.011 and p = 0.001. Although the rate of multiglandular disease was higher in one of the normohormonal variant groups, this difference was due to a higher rate of double adenomas, not four-gland hyperplasia. CONCLUSION: Patients with NHHPT undergoing parathyroidectomy can expect cure rates similar to that in patients with classical PHPT. The results of this study indicate that achieving an 80% drop or more in IOPTH levels predicts a high likelihood of cure. This is true irrespective of whether the patient is deemed normohormonal based on preoperative or intraoperative testing. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:2480-2484, 2024.

Determination of Metabolic Fluxes by Deep Learning of Isotope Labeling Patterns.

Fluxomics offers a direct readout of metabolic state but relies on indirect measurement. Stable isotope tracers imprint flux-dependent isotope labeling patterns on metabolites we measure; however, the relationship between labeling patterns and fluxes remains elusive. Here we innovate a two-stage machine learning framework termed ML-Flux that streamlines metabolic flux quantitation from isotope tracing. We train machine learning models by simulating atom transitions across five universal metabolic models starting from 26 13C-glucose, 2H-glucose, and 13C-glutamine tracers within feasible flux space. ML-Flux employs deep-learning-based imputation to take variable measurements of labeling patterns as input and successive neural networks to convert the ensuing comprehensive labeling information into metabolic fluxes. Using ML-Flux with multi-isotope tracing, we obtain fluxes through central carbon metabolism that are comparable to those from a least-squares method but orders-of-magnitude faster. ML-Flux is deployed as a webtool to expand the accessibility of metabolic flux quantitation and afford actionable information on metabolism.

Tag and Snag: A New Platform for Bioactive Natural Product Screening from Mixtures.

Natural products provide an unparalleled diversity of small molecules to fuel drug screening efforts, but deconvoluting the pharmacological activity of natural product mixtures to identify key bioactive compounds remains a vexing and labor-intensive process. Therefore, we have developed a new platform to probe the non-specific pharmacological potential of compounds present in common dietary supplements via shotgun derivatization with isotopically labeled propanoic acid, a live cell affinity assay, which was used to selectively recognize the population of compounds which bind tightly to HeLa cells in culture, and a computational LC-MS data analysis of isotopically labeled compounds from cell lysate. The data analysis showed that hundreds of compounds were successfully derivatized in each extract, and dozens of those compounds showed high affinity for HeLa cells. In total, over a thousand isotopically labeled compounds were screened for cell affinity across three separate experiments, resulting in the identification of several known bioactive compounds with specific protein targets and six previously unreported structures. The new natural products include three tulsinol compounds which were isolated from Ocimum tenuiflorum and three valeraninium alkaloids from Valeriana officinalis. The valeraninium alkaloids constitute a distinct new family of alkaloids from valerian, which may have previously undescribed bioactivity. These results collectively demonstrate the tag and snag workflow's viability as a drug discovery method.

Science for social licence to arrest an ecosystem-transforming invasion.

The primary role for scientific information in addressing complex environmental problems, such as biological invasions, is generally assumed to be as a guide for management decisions. However, scientific information often plays a minor role in decision-making, with practitioners instead relying on professional experience and local knowledge. We explore alternative pathways by which scientific information could help reduce the spread and impacts of invasive species. Our study centred on attempts to understand the main motivations and constraints of three local governance bodies responsible for the management of invasive (wilding) conifer species in the southern South Island of New Zealand in achieving strategic and operational goals. We used a combination of workshop discussions, questionnaire responses and visits to field sites to elicit feedback from study participants. We applied a mixed inductive-deductive thematic analysis approach to derive themes from the feedback received. The three main themes identified were: (1) impacts of wilding conifers and goals for wilding conifer control, (2) barriers to achieving medium- and long-term goals, and (3) science needed to support wilding conifer control. Participants identified reversal and prevention of both instrumental (e.g. reduced water availability for agriculture) and intrinsic (e.g. loss of biodiversity and landscape values) impacts of wilding conifer invasions as primary motivators behind wilding conifer control. Barriers to achieving goals were overwhelmingly social, relating either to unwillingness of landowners to participate or poorly designed regulatory frameworks. Consequently, science needs related primarily to gaining social licence to remove wilding conifers from private land and for more appropriate regulations. Scientific information provided via spread and impacts forecasting models was viewed as a key source of scientific information in gaining social licence. International experience suggests that invasive species control programmes often face significant external social barriers. Thus, for many biological invasions, the primary role of science might be to achieve social licence and regulatory support for the long-term goals of invasive species control programmes and the management interventions required to achieve those goals.

EBV-positive mucocutaneous ulcer presenting as a nasopharyngeal tumor in an immune suppressed patient.

BACKGROUND: We describe an unusual presentation of EBV-associated mucocutaneous ulcer presenting as a large tumor of the nasopharynx in an immune suppressed child. This condition is newly characterized and has not been well-studied in the otolaryngology literature. CASE REPORT: Our patient is a 12-year-old female undergoing chemotherapy for T-cell acute lymphoblastic leukemia who presented with progressively severe headaches, nasal obstruction, facial pain/pressure, photophobia, fever and otalgia associated with neutropenia and refractory to empiric antibiotic therapy. Bedside nasal endoscopy and imaging revealed signs of acute sinusitis and a large nasopharyngeal mass suspicious for neoplasm. The mass was eccentric to the right and distending the right fossa of Rosenmuller. She underwent endoscopic sinus surgery and biopsy of her nasopharyngeal mass. Pathologic analysis of the nasopharyngeal mass revealed EBV-positive mucocutaneous ulcer. CONCLUSION: This is an unusual presentation of a rare entity. EBV-positive mucocutaneous ulcer warrants awareness among otolaryngologists and is not well-described in our literature.

Integrative metabolic flux analysis reveals an indispensable dimension of phenotypes.

Complete understanding of a biological system requires quantitation of metabolic fluxes that reflect its dynamic state. Various analytical chemistry tools, enzyme-based probes, and microscopy enable flux measurement. However, any method alone falls short of comprehensive flux quantitation. Here we show that integrating these techniques results in a systems-level quantitative map of absolute metabolic fluxes that constitute an indispensable dimension of characterizing phenotypes. Stable isotopes, mass spectrometry, and NMR spectroscopy reveal relative pathway fluxes. Biochemical probes reveal the physical rate of environmental changes. FRET-based and SRS-based microscopy reveal targeted metabolite and chemical bond formation. These techniques are complementary and can be computationally integrated to reveal actionable information on metabolism. Integrative metabolic flux analysis using various quantitative techniques advances biotechnology and medicine.

Correction: Szymanski et al. Recent Advances in Loop Heat Pipes with Flat Evaporator. Entropy 2021, 23, 1374.

The author of the original publication [...].

Influence of design and material characteristics on 3D printed flow-cells for heat transfer-based analytical devices.

Redesigning 3D-printed flow cells is reported used for heat transfer based detection of biomolecules from a flow-through system to an addition-type measurement cell. The aim of this study is to assess the performance of this new measurement design and critically analyse the influence of material properties and 3D printing approach on thermal analysis. Particular attention is paid to reduce the time to stabilisation, the sample volume in order to make the technique suitable for clinical applications, and improving the sensitivity of the platform by decreasing the noise and interference of air bubbles. The three different approaches that were studied included a filament polylactic acid cell using only fused filament fabrication (FFF), a resin cell printed using stereolitography (SLA), and finally a design made of copper, which was manufactured by combining metal injection moulding (MIM) with fused filament fabrication (FFF). Computational fluid dynamic (CFD) modelling was undertaken using ANSYS Fluent V18.1 to provide insight into the flow of heat within the measurement cell, facilitating optimisation of the system and theoretical response speed.It was shown that the measurement cells using SLA had the lowest noise (~ 0.6%) and shortest measurement time (15 min), whereas measurement cells produced using other approaches had lower specificity or suffered from voiding issues. Finally, we assessed the potential of these new designs for detection of biomolecules and amoxicillin, a commonly used beta lactam antibiotic, to demonstrate the proof of concept. It can be concluded that the resin addition-type measurement cells produced with SLA are an interesting affordable alternative, which were able to detect amoxicillin with high sensitivity and have great promise for clinical applications due to the disposable nature of the measurement cells in addition to small sample volumes.

Parathyroid Gland Autofluorescence Characteristics in Patients With Primary Hyperparathyroidism.

OBJECTIVE: Near-infrared imaging for intraoperative parathyroid gland (PG) detection has recently commanded significant attention. The PTeye (Medtronic, Minneapolis, MN) is a probe-based system for near-infrared autofluorescent evaluation of PGs. This study was designed to evaluate the capabilities of the PTeye in the setting of surgery for primary hyperparathyroidism. STUDY DESIGN: Prospective, Cohort study. METHODS: This single-institution, prospective cohort study included all patients undergoing parathyroidectomy for primary hyperparathyroidism with presumed single gland disease from June 2020 to December 2020. Absolute intensity and intensity ratios, with the thyroid as the control tissue, were obtained for the adenoma, ipsilateral normal PG, and adjacent tissue. The ability of the PTeye to function when not in direct contact with tissue was measured. RESULTS: Twenty-two patients were included. The median intensity ratio for the in situ adenomas was 4.38 (interquartile range [IQR]: 2.03-5.87), ipsilateral normal PGs 6.17 (IQR: 3.83-7.67), strap muscle 0.47 (IQR: 0.30-0.60), and fat 0.20 (IQR: 0.17-0.47). All normal PGs and 21/22 adenomas demonstrated autofluorescence above the detection threshold. The PTeye functioned at a maximum distance of separation of 10 mm through saline medium and 6 mm through clear solid medium. CONCLUSION: This study confirms the PTeye's ability to recognize PGs with a high degree of precision. The device was found to function properly even with the probe not in direct contact with the tissue. Although adenomatous PGs appear to demonstrate altered autofluorescent properties from normal PGs, additional research is required to determine if these differences are clinically useful. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:715-721, 2022.

Recent Advances in Loop Heat Pipes with Flat Evaporator.

The focus of this review is to present the current advances in Loop Heat Pipes (LHP) with flat evaporators, which address the current challenges to the wide implementation of the technology. A recent advance in LHP is the design of flat-shaped evaporators, which is better suited to the geometry of discretely mounted electronics components (microprocessors) and therefore negate the need for an additional transfer surface (saddle) between component and evaporator. However, various challenges exist in the implementation of flat-evaporator, including (1) deformation of the evaporator due to high internal pressure and uneven stress distribution in the non-circular casing; (2) heat leak from evaporator heating zone and sidewall into the compensation chamber; (3) poor performance at start-up; (4) reverse flow through the wick; or (5) difficulties in sealing, and hence frequent leakage. This paper presents and reviews state-of-the-art LHP technologies; this includes an (a) review of novel manufacturing methods; (b) LHP evaporator designs; (c) working fluids; and (d) construction materials. The work presents solutions that are used to develop or improve the LHP construction, overall thermal performance, heat transfer distance, start-up time (especially at low heat loads), manufacturing cost, weight, possibilities of miniaturization and how they affect the solution on the above-presented problems and challenges in flat shape LHP development to take advantage in the passive cooling systems for electronic devices in multiple applications.

Sensationalist social media usage by doctors and dentists during Covid-19.

INTRODUCTION: Many doctors and dentists took to social media to raise alarm and/or express professional opinion, dissatisfaction, anger and/or incredulity associated with the Covid-19 pandemic. Although most of these social media posts involved practitioners from abroad, this article explores whether they would attract fitness to practise investigations had they been posted by UK-based medical and dental practitioners. In particular, it asks whether such conduct comes into conflict with the existing professional standards issued by the General Medical Council (GMC) and the General Dental Council (GDC). It questions also whether those guidelines should be updated and/or further clarified in view of the extraordinary circumstances posed by the pandemic. METHOD: An exploratory study was conducted using sensationalist pandemic-related social media posts by doctors and dentists discovered during the first half of 2020 (n = 11). The contents were analysed qualitatively using documentary analysis using coding terms based on the professional standards on social media published by both the GMC and the GDC. The codes generated common and recurring themes that were used to structure discussion. FINDINGS: This study provides a partial insight as to the likely motivations of doctors and dentists to use social media in a manner that may not necessarily lend well to the professional standards expected. In a majority of instances, doctors and dentists who posted social media material with a sensationalist outlook tended to focus on single-issue campaigns pertaining to specific aspects of the Covid-19 pandemic. These issues included controversial commentary on acute shortages of personal protective equipment and attendant occupational risks to clinical staff to Covid-19 infection; criticisms directed towards regulatory bodies in the handling of the pandemic; and professional advice to the general public which was later found to be inaccurate. CONCLUSIONS: Social media offer opportunities for healthcare professionals to play a constructive role in raising awareness, disseminating information, and promoting solidarity in the management of the Covid-19 pandemic. However, doctors and dentists must carefully consider the ethical and professional pitfalls involved in sensationalist social media posts. The GMC and the GDC should, at the same time, regularly update and clarify their social media guidance in response to major global events like a pandemic as well as advances in social media technology.

Hyperparathyroidism subsequent to radioactive iodine therapy for Graves' disease.

BACKGROUND: The development of primary hyperparathyroidism (PHPT) after radioactive iodine (RAI) treatment for thyroid disease is poorly characterized. The current study is the largest reported cohort and assesses the disease characteristics of patients treated for PHPT with a history of RAI exposure. METHODS: A retrospective analysis comparing patients, with and without a history of RAI treatment, who underwent surgery for PHPT. RESULTS: Twenty-eight of the 469 patients had a history of RAI treatment, all for Graves' disease. Patients with a history of RAI exposure had similar disease characteristics compared to control; however, patients with a history of RAI treatment had a higher rate of recurrence (7.4% vs 1.2%, p = 0.012). CONCLUSION: PHPT in patients with a history of RAI treatment can be approached in the same manner as RAI naive PHPT patients; however, the risk of recurrence of PHPT in RAI exposed patients may be higher.

Projected Wine Grape Cultivar Shifts Due to Climate Change in New Zealand.

Climate change has already been affecting the regional suitability of grapevines with significant advances in phenology being observed globally in the last few decades. This has significant implications for New Zealand, where the wine industry represents a major share of the horticultural industry revenue. We modeled key crop phenological stages to better understand temporal and spatial shifts in three important regions of New Zealand (Marlborough, Hawke's Bay, Central Otago) for three dominant cultivars (Merlot, Pinot noir, and Sauvignon blanc) and one potential new and later ripening cultivar (Grenache). Simulations show an overall advance in flowering, véraison, and sugar ripeness by mid-century with more pronounced advance by the end of the century. Results show the magnitude of changes depends on the combination of greenhouse gas emission pathway, grape cultivar, and region. By mid-century, in the Marlborough region for instance, the four cultivars would flower 3 to 7 days earlier and reach sugar ripeness 7 to 15 days earlier depending on the greenhouse gas emission pathway. For growers to maintain the same timing of key phenological stages would require shifting planting of cultivars to more Southern parts of the country or implement adaptation strategies. Results also show the compression of time between flowering and véraison for all three dominant cultivars is due to a proportionally greater advance in véraison, particularly for Merlot in the Hawke's Bay and Pinot noir in Central Otago. Cross-regional analysis also raises the likelihood of the different regional cultivars ripening within a smaller window of time, complicating harvesting schedules across the country. However, considering New Zealand primarily accommodates cool climate viticulture cultivars, our results suggest that late ripening cultivars or extended ripening window in cooler regions may be advantageous in the face of climate change. These insights can inform New Zealand winegrowers with climate change adaptation options for their cultivar choices.

Does insurance type influence overall survival in patients with laryngeal squamous cell carcinoma?

OBJECTIVE: Patients with head and neck cancer with Medicaid or no insurance present at a more advanced stage and have lower survival. This study is one of the first to examine the relationship between specific insurance types and overall survival for laryngeal squamous cell carcinoma patients. STUDY DESIGN: Retrospective chart review. SETTING: Henry Ford Cancer Institute. SUBJECTS AND METHODS: A retrospective database review was performed using the Henry Ford Virtual Data Warehouse Tumor Registry. Six hundred and fifty patients diagnosed with laryngeal squamous cell carcinoma were identified. Insurance groups analyzed were fee for service, health maintenance organization, Henry Ford Medical Group - a managed care type insurance, Medicare and Medicaid/uninsured. Cox proportional hazards and Kaplan-Meier curves were generated to analyze overall survival and display survival differences respectively. RESULTS: The uninsured group had the lowest median survival time of 29.8 months (95% CI: 20.3-44.8) and the highest HR of 1.85 (95% CI 1.16-2.93) as compared to the HMO group at p < 0.001. Patients with fee for service insurance had longer overall survival compared to the other insurance types. Patients with fee for service insurance also had a high proportion of patients with advanced stage disease, but a younger mean age. Henry Ford Medical Group had a higher mean age and no statistically significant difference in survival when compared to fee for service. (p = 0.999) After controlling for socioeconomic status, insurance type remains a significant predictor of overall survival. CONCLUSIONS: Fee for service had the highest overall survival of the different insurance types, but it was only statistically significant when compared to the Medicaid/uninsured group.