National Survey of Current Follow-up Protocols for Patients Treated for Endometrial Cancer in the UK

AIMS

The aim of this study was to establish a baseline of national practice for follow-up after treatment for endometrial cancer in the UK.

MATERIALS AND METHODS

An online cross-sectional survey was developed and distributed through the Royal College of Radiologists via an email link to the audit leads of radiotherapy centres in the UK. The survey was conducted from November 2021 to 5 January 2022. The main themes assessed in the survey were the form, frequency and duration of follow-up practices.

RESULTS

There were a total of 43/61 (70%) complete responses. 93% of centres had a standard follow-up protocol and 7% who did not have a follow-up protocol discharged patients after the post-operative review. Five centres (13%) used molecular profiling to inform follow-up practices. Patient-initiated follow-up was mainly used in the cohort of patients who had surgery alone with no adjuvant treatment (68%, (19/28)). In the cohort who had face-to-face follow-up, the majority had pelvic examinations as part of their review and total follow-up for five years. 93% of respondents are interested in a national follow-up protocol.

CONCLUSION

Our data shows that there is national variation in practise with regard to follow-up of women treated for endometrial cancer. Many of the follow-up practises are based on conventional follow-up regimens and these may fail to address the more holistic needs of cancer survivors. Recent publication of updated guidance from the British Gynaecological Cancer Society may help standardise practise and provide a more relevant approach to follow-up for women treated for endometrial cancer.

Capnodynamic monitoring of lung volume and pulmonary blood flow during alveolar recruitment: a prospective observational study in postoperative cardiac patients

Alveolar recruitment manoeuvres may mitigate ventilation and perfusion mismatch after cardiac surgery. Monitoring the efficacy of recruitment manoeuvres should provide concurrent information on pulmonary and cardiac changes. This study in postoperative cardiac patients applied capnodynamic monitoring of changes in end-expiratory lung volume and effective pulmonary blood flow. Alveolar recruitment was performed by incremental increases in positive end-expiratory pressure (PEEP) to a maximum of 15 cmH2O from a baseline of 5 cmH2O over 30 min. The change in systemic oxygen delivery index after the recruitment manoeuvre was used to identify responders (> 10% increase) with all other changes (≤ 10%) denoting non-responders. Mixed factor ANOVA using Bonferroni correction for multiple comparisons was used to denote significant changes (p < 0.05) reported as mean differences and 95% CI. Changes in end-expiratory lung volume and effective pulmonary blood flow were correlated using Pearson's regression. Twenty-seven (42%) of 64 patients were responders increasing oxygen delivery index by 172 (95% CI 61-2984) mL min-1 m-2 (p < 0.001). End-expiratory lung volume increased by 549 (95% CI 220-1116) mL (p = 0.042) in responders associated with an increase in effective pulmonary blood flow of 1140 (95% CI 435-2146) mL min-1 (p = 0.012) compared to non-responders. A positive correlation (r = 0.79, 95% CI 0.5-0.90, p < 0.001) between increased end-expiratory lung volume and effective pulmonary blood flow was only observed in responders. Changes in oxygen delivery index after lung recruitment were correlated to changes in end-expiratory lung volume (r = 0.39, 95% CI 0.16-0.59, p = 0.002) and effective pulmonary blood flow (r = 0.60, 95% CI 0.41-0.74, p < 0.001). Capnodynamic monitoring of end-expiratory lung volume and effective pulmonary blood flow early in postoperative cardiac patients identified a characteristic parallel increase in both lung volume and perfusion after the recruitment manoeuvre in patients with a significant increase in oxygen delivery.Trial registration This study was registered on ClinicalTrials.gov (NCT05082168, 18th of October 2021).

Smoky heart: cardiovascular manifestations of carbon monoxide poisoning

Background

Carbon monoxide (CO) poisoning is one of the most critical health concerns worldwide due to severe clinical effects with high morbidity and mortality. Tissue hypoxia and cellular damage from CO poisoning results in oxidative stress. Organs and tissues with high O2 demand including central nervous system (CNS) and cardiovascular (CV) system are the most susceptible to this oxidative stress. We investigate and describe the cardiovascular manifestations in 350 patients who were admitted for moderate to severe CO poisoning and treated with hyperbaric oxygen (HBO2) therapy.

Purpose

This study was conducted to identify the common cardiovascular manifestations of carbon monoxide poisoning.

Methods

We retrospectively collected data on 350 consecutive adult patients treated for CO poisoning between January 2011 to April 2018. Cardiac biomarkers, EKG and carboxyhemoglobin (COHb) levels were obtained from pre-hospital sources including EMS (emergency medical services) and from outside hospital records at the time of transfer. Glasgow Coma Scale (GCS) measurements were obtained at initial pre-hospital evaluation and upon arrival to the emergency room. Patient demographics, CV, CNS history and cardiac risk factors including hypertension, hyperlipidemia, diabetes, smoking history were obtained from electronic medical record. Myocardial injury was defined by cardiac troponin I level of ≥0.05 ng/mL.

Results

There were 350 patients admitted for CO poisoning from 2011 to 2018. 72% of the patients received HBO treatment due to severity of their symptoms. The mean age was 47.3 years with 60% men, 89% of the admissions were accidental exposure. Cardiac biomarkers were elevated in 40% of the patients and with 21% having sinus tachycardia. 6% had ischemic EKG changes with 23% having regional wall motion abnormalities on echocardiogram. In terms of intervention, 83% of the patients with elevated cardiac biomarkers received HBO treatment, 9% underwent coronary angiogram out of which 50% were candidate for either percutaneous intervention (PCI) or coronary artery bypass graft (CABG). In hospital mortality amongst this population was 2%.

Conclusion

Myocardial injury is common and widely seen with CO poisoning as seen by elevated cardiac biomarkers in 40% of the tested population. Initial work up for patients with CO poisoning should include evaluation with an EKG and serial biomarkers. If an abnormality is detected, patient should undergo an echocardiogram. Further evaluation with coronary angiography may be warranted in patients with new left ventricular dysfunction or wall motion abnormalities, especially in patients with risk factors.

Funding Acknowledgement

Type of funding sources: None.

Fighting antibiotic resistance: a narrative review of public knowledge, attitudes, and perceptions of antibiotics use

AIMS

The aims of this study were to ascertain the comprehensive knowledge, perceptions, and attitudes of people from varying socioeconomic regions towards antibiotic use; identify the misperceptions and malpractices; and inform health policy and practice.

METHOD

EBSCO host databases, PubMed, and Google Scholar were searched to obtain relevant primary research papers within the years 2010-2018. Search phrases included the following: 'antibiotics use', 'community perceptions', 'public opinion, knowledge, behaviour, practices, perceptions'. Initially, selected papers were screened using the Preview, Question, Read, Summarize (PQRS) model.

RESULTS

Review of the 20 articles selected was based on six identified themes. It was found that insufficient knowledge and awareness of antibiotics use; self-medication and the use of leftover antibiotics; treating viral diseases with antibiotics or used as painkillers; expecting antibiotic prescription as a culmination of consultation; and the credibility of information obtained are issues that cut across different countries.

CONCLUSION

Evidence from this review suggests that misconceptions of antibiotic use are similar in different countries. Therefore, the need for the development and implementation of transferable policies as well as educating the public is necessary for the fight against ABR.

Strain-Dependent Inhibition of Clostridioides difficile by Commensal Clostridia Carrying the Bile Acid-Inducible (bai) Operon

Clostridioides difficile is one of the leading causes of antibiotic-associated diarrhea. Gut microbiota-derived secondary bile acids and commensal Clostridia that carry the bile acid-inducible (bai) operon are associated with protection from C. difficile infection (CDI), although the mechanism is not known. In this study, we hypothesized that commensal Clostridia are important for providing colonization resistance against C. difficile due to their ability to produce secondary bile acids, as well as potentially competing against C. difficile for similar nutrients. To test this hypothesis, we examined the abilities of four commensal Clostridia carrying the bai operon (Clostridium scindens VPI 12708, C. scindens ATCC 35704, Clostridium hiranonis, and Clostridium hylemonae) to convert cholate (CA) to deoxycholate (DCA) in vitro, and we determined whether the amount of DCA produced was sufficient to inhibit the growth of a clinically relevant C. difficile strain. We also investigated the competitive relationships between these commensals and C. difficile using an in vitro coculture system. We found that inhibition of C. difficile growth by commensal Clostridia supplemented with CA was strain dependent, correlated with the production of ∼2 mM DCA, and increased the expression of bai operon genes. We also found that C. difficile was able to outcompete all four commensal Clostridia in an in vitro coculture system. These studies are instrumental in understanding the relationship between commensal Clostridia and C. difficile in the gut, which is vital for designing targeted bacterial therapeutics. Future studies dissecting the regulation of the bai operon in vitro and in vivo and how this affects CDI will be important.IMPORTANCE Commensal Clostridia carrying the bai operon, such as C. scindens, have been associated with protection against CDI; however, the mechanism for this protection is unknown. Herein, we show four commensal Clostridia that carry the bai operon and affect C. difficile growth in a strain-dependent manner, with and without the addition of cholate. Inhibition of C. difficile by commensals correlated with the efficient conversion of cholate to deoxycholate, a secondary bile acid that inhibits C. difficile germination, growth, and toxin production. Competition studies also revealed that C. difficile was able to outcompete the commensals in an in vitro coculture system. These studies are instrumental in understanding the relationship between commensal Clostridia and C. difficile in the gut, which is vital for designing targeted bacterial therapeutics.

Steady state pharmacokinetics of cycloserine in patients on terizidone for multidrug-resistant tuberculosis

SETTING

Terizidone/cycloserine (TRD/CS) is included in standard treatment regimens for multidrug-resistant tuberculosis (MDR-TB) in many countries. The steady state pharmacokinetics (PKs) of CS after TRD administration are not known.

OBJECTIVES AND DESIGN

We recruited in-patients treated with 250-750 mg oral TRD daily as part of standard treatment regimens for pulmonary MDR-TB in Cape Town, South Africa. Plasma CS assays were performed in samples taken pre-dose and at 2, 4, 6, 8 and 10 h post-dose. CS concentrations were measured using a validated liquid chromatography-tandem mass spectrometry method. Non-compartmental PK analyses were performed.

RESULTS

Of 35 participants enrolled, 22 were males, and 20 (57%) were infected with the human immunodeficiency virus; the median age was 37 years. The median duration on TRD at the time of sampling was 33 days (interquartile range [IQR] 28-39). The area under the concentration-time curve at 0-10 h (AUC0-10) was 319 μg.h/ml (IQR 267.5-378.7), and peak concentration was 38.1 μg/ml (IQR 32.6-47.2). On multiple regression, dose (mg/kg) was the only factor independently associated with AUC0-10.

CONCLUSION

Steady state concentrations of CS in patients treated with TRD for MDR-TB were higher than those reported with CS formulations. Our findings support once-daily dosing.

Anti-fracture efficacy of zoledronate in subgroups of osteopenic postmenopausal women: secondary analysis of a randomized controlled trial

BACKGROUND

We recently reported that the administration of zoledronate every 18 months to osteopenic older women reduces the incidence of fractures.

OBJECTIVE

Here, we present a more detailed analysis of that trial to determine whether baseline clinical characteristics impact on the anti-fracture efficacy of this intervention.

METHODS

This is a prospective, randomized, placebo-controlled, double-blind trial in osteopenic postmenopausal women aged ≥ 65 years, to determine the anti-fracture efficacy of zoledronate. 2000 women were recruited using electoral rolls and randomized to receive 4 infusions of either zoledronate 5 mg or normal saline, at 18-month intervals. Each participant was followed for 6 years. Calcium supplements were not supplied.

RESULTS

Fragility fractures (either vertebral or nonvertebral) occurred in 190 women in the placebo group (227 fractures) and in 122 women in the zoledronate group (131 fractures), odds ratio (OR) 0.59 (95%CI 0.46, 0.76; P < 0.0001). There were no significant interactions between baseline variables (age, anthropometry, BMI, dietary calcium intake, baseline fracture status, recent falls history, bone mineral density, calculated fracture risk) and the treatment effect. In particular, the reduction in fractures appeared to be independent of baseline fracture risk, and numbers needed to treat (NNT) to prevent one woman fracturing were not significantly different across baseline fracture risk tertiles.

CONCLUSIONS

The present analyses indicate that the decrease in fracture numbers is broadly consistent across this cohort. The lack of relationship between NNTs and baseline fracture risk calls into question the need for BMD measurement and precise fracture risk assessment before initiating treatment in older postmenopausal women.

Adapting the Structured Operational Research Training Initiative (SORT IT) for high-income countries

SORT IT (Structured Operational Research Training InitiaTive) is a successful capacity building programme started 10 years ago to develop operational research skills in low- and middle-income countries. Public Health England (PHE) aims to embed a culture of research in front-line staff, and SORT IT has been adapted to train frontline health protection professionals at PHE North West (PHE NW) to collate, analyse and interpret routinely collected data for evidence-informed decision-making. Six participants from the PHE NW Health Protection team were selected to attend a two-module course in Liverpool, UK, in May and in November 2018. Five participants finished the course with completed papers on characteristics and burden of influenza-like illness in elderly care homes (two papers), use of dried blood spots for blood-borne virus screening in prisons, uptake of meningococcal ACWY (groups A, C, W-135 and Y) vaccine in schoolchildren and fires in waste management sites. The SORT IT course led to 1) new evidence being produced to inform health protection practice, and 2) agreement within PHE NW to continue SORT IT with two courses per year, and 3) showed how a research capacity building initiative for low- and middle-income countries that combines 'learning with doing' can be adapted and used in a high-income country.

Prebiotic oligosaccharides in early life alter gut microbiome development in male mice while supporting influenza vaccination responses

Beneficial modulation of the gut microbiota is an attractive therapeutic approach to improve the efficacy of vaccine-induced immunity. In this study, mice were supplemented with the prebiotic milk oligosaccharide 2'-fucosyllactose (2'FL) as well as a complex mixture of immune modulatory prebiotic short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides (scGOS/lcFOS) from different stages in early life. Adult mice were vaccinated with trivalent influenza vaccine (TIV) and both development of the gut microbiota and antibody-mediated vaccine responses were followed over time. Within the control group, female mice demonstrated a larger antibody response to TIV vaccination than male mice, which was accompanied by enhanced cytokine production by splenocytes and a higher percentage of plasma cells in skin draining lymph nodes. In addition, the prebiotic diet improved vaccine-specific antibody responses in male mice. Introduction of prebiotics into the diet modulated the gut microbiota composition and at the genus level several bacterial groups showed a significant interaction effect which potentially contributed to the immunological effects observed. This study provides insight in the effect of scGOS/lcFOS/2'FL in influenza vaccination antibody production.

Ab initio structure determination of nanocrystals of organic pharmaceutical compounds by electron diffraction at room temperature using a Timepix quantum area direct electron detector. Corrigendum

Corrections are made to Table 1 in the article by van Genderen et al. [Acta Cryst. (2016), A72, 236-242].

The cost of infection: Argulus foliaceus and its impact on the swimming performance of the three-spined stickleback (Gasterosteus aculeatus)

For fish, there can be multiple consequences of parasitic infections, including the physical impacts on swimming and the pathological costs of infection. This study used the three-spined stickleback (Gasterosteus aculeatus) and the ectoparasitic fish louse, Argulus foliaceus, to assess both physical (including form drag and mass) and pathological effects of infection. Both sustained (prolonged swimming within an open channel flume) and burst (C-start) swimming performance were measured on individual fish before (trials 1-2) and after infection (trials 3-5). Experimental infection occurred shortly before the third trial, when the physical impacts of infection could be separated from any subsequent pathology as transmission of adult parasites causes instantaneous drag effects prior to observable pathology. Despite the relatively large size of the parasite and corresponding increase in hydrodynamic drag for the host, there were no observable physical effects of infection on either sustained or burst host swimming. By contrast, parasite-induced pathology is the most probable explanation for reduced swimming performance across both tests. All sticklebacks displayed a preference for flow refugia, swimming in low-velocity regions of the flume, and this preference increased with both flow rate and infection time. This study suggests that even with large, physically demanding parasites their induced pathology is of greater concern than direct physical impact.

Contact X-ray Brachytherapy as an Adjunct to a Watch and Wait Approach is an Affordable Alternative to Standard Surgical Management of Rectal Cancer for Patients with a Partial Clinical Response to Chemoradiotherapy

AIMS

Emerging evidence suggests that contact X-ray brachytherapy (CXB) may increase the clinical complete response rate and durability when administered after standard chemoradiotherapy in patients with rectal cancer. The addition of CXB in partial responders is therefore probably cost-effective. The affordability of widening access to CXB in the UK, however, has not been evaluated.

MATERIALS AND METHODS

Decision analytical modelling with Monte Carlo simulation was used to evaluate long-term costs for the management of patients with rectal cancers who were given a CXB boost when a clinical complete response was not initially achieved following chemoradiotherapy in order to facilitate a watch and wait approach. A third-party payer (National Health Service) perspective was adopted, probabilistic sensitivity analysis was carried out and a scenario analysis was performed to investigate the effect of the number of referral centres and number of patients treated with CXB.

RESULTS

We estimate that 818 (95% confidence interval 628-1021) patients per year are eligible for CXB as an adjunct to a watch and wait approach in England and Wales. As this management is less costly than surgical management for each individual patient, the more patients treated, the more affordable the technology. Even if as few as 125 patients are treated nationally in 15 centres, the cost of implementing this technology would be less than £4 million. If the average number of patients treated in each centre is 30, this technology would be cost saving within 5 years.

CONCLUSIONS

The cost of CXB is not prohibitive according to the National Institute for Health and Care Excellence threshold for implementation of new technology and may even be cost saving within 5 years compared with standard surgical management, depending on the uptake of the technology and the number of referral centres.

Metastatic endometrial cancer of the paranasal sinuses

Endometrial carcinoma is the fourth most common cancer affecting women in the UK. Its most frequent sites of spread are to the pelvic and para-aortic lymph nodes, vagina and peritoneum. We report a case of a 63-year-old woman with known endometrial cancer who presented with left facial swelling and eye displacement. Investigations revealed an expansile soft-tissue density mass arising within the bone, centred on the left zygoma, with exophytic extension into the left maxillary antrum, infratemporal fossa and inferiorly into the orbit. Endoscopic biopsies were taken and histology confirmed metastatic deposits of endometrial cancer. Clinicians should be aware that distant spread of endometrial cancer is linked with advanced disseminated disease and palliative treatments should be considered.

Effect of lidocaine on kanamycin injection-site pain in patients with multidrug-resistant tuberculosis

SETTING

Reducing pain from intramuscular injection of kanamycin (KM) could improve the tolerability of multidrug-resistant tuberculosis (MDR-TB) treatment. Lidocaine has been shown to be an effective anaesthetic diluent for some intramuscular injections, but has not been investigated with KM in the treatment of adult patients with MDR-TB.

OBJECTIVE AND DESIGN

We performed a randomised single-blinded crossover study to determine if lidocaine reduces KM injection-site pain. We recruited patients aged 18 years on MDR-TB treatment at two TB hospitals in Cape Town, South Africa. KM pharmacokinetic parameters and a validated numeric pain scale were used at intervals over 10 h following the injection of KM with and without lidocaine on two separate occasions.

RESULTS

Twenty participants completed the study: 11 were males, the median age was 36 years, 11 were HIV-infected, and the median body mass index was 17.5 kg/m2. The highest pain scores occurred early, and the median pain score was 0 by 30 min. The use of lidocaine with KM significantly reduced pain at the time of injection and 15 min post-dose. On multiple regression analysis, lidocaine halved pain scores (adjusted OR 0.5, 95%CI 0.3-0.9). The area under the curve at 0-10 h of KM with and without lidocaine was respectively 147.7 and 143.6 μg·h/ml.

CONCLUSION

Lidocaine significantly reduces early injection-site pain and has no effect on KM pharmacokinetics.

Factors associated with lumbo-pelvic pain in recreational cyclists

Background: Overuse injuries in cyclists are as high as 85%, with lower back and pelvis pain (LBPP) being common. The lower back and pelvis are pivotal to powering and controlling the bicycle and essential for optimal functioning, comfort and performance. Cyclists spend long, continuous hours in sustained forward flexion, which is regarded as a main contributor to LBPP. Cyclists with LBPP assume greater lumbar flexion but the reason has not yet been established. Objectives: To identify intrinsic and bicycle set-up factors associated with lumbo-pelvic pain in cyclists. Methods: This study was cross-sectional and descriptive. One hundred and twenty-one cyclists in Gauteng, South Africa, participated in this study. The factors proposed to be associated with LBPP were determined to be namely: lumbar curvature on the bicycle in all three handlebar positions, strength of the gluteus maximus (Gmax) and medius (Gmed), extensibility of the hamstrings, control of lumbar movement in the direction of flexion, neurodynamics, active straight leg raise, one leg stance test for lateral pelvic shift, leg length discrepancy and bicycle set-up (saddle height, set-back and angle, handlebar height, forward reach, cleat position). Results: Only the lumbar curvature in the brake lever position (p=0.03) and weakness of the Gmed (p=0.05) were related to LBPP in cyclists. Conclusion: This study was the first to assess the relationship between the multiple factors described above and LBPP in cyclists. Understanding the relationship between increased lumber flexion in the brake lever position and the weakness of the Gmed and LBPP may lead to the development of strategies to reduce LBPP occurrence.

Alarming rates of attrition among tuberculosis patients in public-private facilities in Lahore, Pakistan

Setting: All public-private mix (PPM) facilities caring for tuberculosis (TB) patients in Lahore city, Pakistan, under four models: PPM1 (general practitioners), PPM2 (non-governmental organisations), PPM3 (private hospitals) and PPM4 (others). Objective: To assess the pre-treatment loss to follow-up (LTFU), defined as patients documented in the laboratory registers but not in the treatment registers of any PPM facility, among sputum smear-positive TB patients diagnosed during January-March 2015, and unfavourable treatment outcomes among patients registered for treatment and associated factors. Design: This was a retrospective cohort study reviewing existing programme records. Poisson regression was used to identify factors associated with outcomes. Results: Of 2473 patients diagnosed, 1590 (64%) were lost to follow-up before treatment. This was higher among males (68%) and the elderly (79%), and lower among 'high positives' (smear grading 2+ or 3+, 53%) and in the PPM1 model (34%). Of 883 patients started on treatment, 165 (19%) had unfavourable outcomes: 8% LTFU, 5% treatment failure, 3% died and 3% not evaluated. Previously treated patients (34%) and children (44%) had the worst outcomes. Conclusion: Pre-treatment LTFU was alarmingly high and requires urgent attention, including the development and institution of mechanisms for patient tracking using information and mobile phone technology, and making TB notification mandatory in the private sector.

Metabolic and reproductive plasticity of core and marginal populations of the eurythermic saline water bug Sigara selecta (Hemiptera: Corixidae) in a climate change context

Ongoing climate change is driving dramatic range shifts in diverse taxa worldwide, and species responses to global change are likely to be determined largely by population responses at geographical range margins. Here we investigate the metabolic and reproductive plasticity in response to water temperature and salinity variation of two populations of the eurythermic saline water bug Sigara selecta: one population located close to the northern edge of its distribution, in a relatively cold, thermally stable region (SE England - 'marginal'), and one close to the range centre, in a warmer and more thermally variable Mediterranean climate (SE Spain - 'core'). We compared metabolic and oviposition rates and egg size, following exposure to one of four different combinations of temperature (15 and 25°C) and salinity (10 and 35gL^-1). Oviposition rate was significantly higher in the marginal population, although eggs laid were smaller overall. No significant differences in oxygen consumption rates were found between core and marginal populations, although the marginal population showed higher levels of plasticity in both metabolic and reproductive traits. Our results suggest that population-specific responses to environmental change are complex and may be mediated by differences in phenotypic plasticity. In S. selecta, the higher plasticity of the marginal population may facilitate both its persistence in current habitats and northward expansion with future climatic warming. The less plastic core population may be able to buffer current environmental variability with minor changes in metabolism and fecundity, but could be prone to extinction if temperature and salinity changes exceed physiological tolerance limits in the future.

Body size and vocalization in primates and carnivores

A fundamental assumption in bioacoustics is that large animals tend to produce vocalizations with lower frequencies than small animals. This inverse relationship between body size and vocalization frequencies is widely considered to be foundational in animal communication, with prominent theories arguing that it played a critical role in the evolution of vocal communication, in both production and perception. A major shortcoming of these theories is that they lack a solid empirical foundation: rigorous comparisons between body size and vocalization frequencies remain scarce, particularly among mammals. We address this issue here in a study of body size and vocalization frequencies conducted across 91 mammalian species, covering most of the size range in the orders Primates (n = 50; ~0.11-120 Kg) and Carnivora (n = 41; ~0.14-250 Kg). We employed a novel procedure designed to capture spectral variability and standardize frequency measurement of vocalization data across species. The results unequivocally demonstrate strong inverse relationships between body size and vocalization frequencies in primates and carnivores, filling a long-standing gap in mammalian bioacoustics and providing an empirical foundation for theories on the adaptive function of call frequency in animal communication.