Short Tandem Repeat (STR) Profiling of Earwax DNA Obtained from Healthy Volunteers.

The present study aimed to establish human earwax as a potential source of DNA evidence that could be effectively used in human identification. Sixty earwax samples were obtained from 15 healthy male and female Saudi volunteers living in Riyadh, Saudi Arabia. Four consecutive earwax swab samples were obtained from each volunteer and stored for 1, 15, 30 and 60 days. Earwax samples were stored at room temperature (20-22 °C). Reference oral swab was also taken from each volunteer. DNA was extracted by QIAamp DNA Mini kit and quantified by real-time polymerase chain reaction (RT-PCR) on 7500 Thermal Cycler. Autosomal STR loci were amplified using AmpFLSTR™ Identifiler™ Plus PCR Amplification Kit (Thermo Fisher Scientific, Carlsbad, CA, USA). Amplified fragments were size separated and analyzed on a 3500 Genetic Analyzer. Complete autosomal STR profiles were obtained from the earwax swabs of all the volunteers stored up to 30 days after the collection. Some STR profiles were partially obtained 60 days after the earwax collection. Allelic drop-out, allelic drop-in, and stutters were seen in earwax samples analyzed 60 days after the collection. The results have shown that human earwax can be a potential source of DNA evidence for human identification up to 30 days after the earwax collection. It is recommended to quickly analyze earwax samples or store them at room temperature or at -10 °C after their recovery from the crime scene.

[Microbiome of the external auditory canal and preoperative preparation of patients in otosurgery (literature review)]. / Mikrobiom naruzhnogo slukhovogo prokhoda i predoperatsionnaya podgotovka patsientov v otokhirurgii (obzor literatury).

OBJECTIVE: To analyze the effectiveness of methods of antiseptic and hygienic preoperative preparation of the operating field in otosurgery. MATERIAL AND METHODS: A review and an expert assessment of the corresponding research objectives of scientific publications contained in the PubMed and Google Scholar databases have been carried out. RESULTS: Various studies indicate a lower ototoxicity of 5-10% of the drug povidone-iodine compared to others. Drugs, such as Miramistin, Okomistin, Dioxidine, are actively used in otiatrics in Russia, but no data on their ototoxicity have been noted. The collected data point to the relevance and prospects of studying the microbiome of the external auditory canal, assessing its effect on the course of the postoperative period, depending on various methods of preparation (antiseptic, removal of earwax and hair depilation) of the surgical field for otosurgery.

Identification of cattle poisoning by Bifenthrin via earwax analysis by HS/GC-MS.

The use of pyrethroids has increased over recent years, and corresponds to a higher exposure of animals to pesticide residues in the environment and diet. Here, an outbreak of pyrethroid poisoning in beef cattle was reported occurring in Midwestern Brazil. After veterinary evaluation, it was observed that the bovines presented common pyrethroid intoxication symptoms. Aiming to identify the cattle poising by pyrethroid, earwax samples were collected from two groups: exposed and nonexposed animals from the same farm. Blind earwax analyses of the bovines were carried out using headspace/gas chromatography-mass spectrometry (HS/GC-MS). The HS/GC-MS analysis detected the presence of bifenthrin in the earwax analysis of the exposed animals, confirmed by the comparison of its MS fragments with a bifenthrin standard, and also by its retention time relative to the internal standard. In summary, HS/GC-MS analysis of earwax emerges as a tool that can be used in the detection and monitoring of bifenthrin poisoning in cattle, as a useful veterinary diagnosis that ensures animal health and the safety of their products.

Cerumenolytics with or without manual extraction for impacted earwax: A network meta-analysis of randomised clinical trials.

BACKGROUND: Many different substances for cerumenolysis have been evaluated in clinical trials. We carried out a systematic review and network meta-analysis to compare their effectiveness. METHODS: Electronic databases were searched for randomised clinical trials conducted in patients with impacted cerumen evaluating cerumenolytics. The primary outcome was the proportion of patients with wax clearance using manual techniques. Rankogram plot was used to assess the "best" cerumenolytic. Odds ratio (OR) with 95% confidence intervals (95% CI) was the effect estimate. RESULTS: Twenty-six studies were included in the systematic review and 25 in the meta-analysis. Sodium bicarbonate (OR: 2.68, 95% CI: 1.2, 6.1) and paradichlorobenzene (OR: 30.9, 95% CI: 5.9, 161.3) were associated with significantly greater proportions of patients with wax clearance following syringing compared to normal saline. Rankogram plot revealed paradichlorobenzene to have the highest probability of being the "best" cerumenolytic. Chlorobutanol was observed to be significantly better than normal saline in adults as well as following single application. Following multiple applications, glycerol, docusate sodium, hydrogen peroxide, oil, paradichlorobenzene, hydrogen peroxide/glycerol and arachis oil/chlorobutanol/paradichlorobenzene were observed with significant cerumenolytic activities. Urea/hydrogen peroxide/glycerol was observed with a significant cerumenolytic activity without the need for further interventions such as syringing/aspiration/suction. CONCLUSION: We observed several cerumenolytics to be effective in the treatment of impacted earwax when accompanied by additional manual techniques such as syringing/aspiration/suction.

Temporary threshold shift following ear canal microsuction.

Objectives: To investigate a temporary threshold shift (TTS) of hearing and pain/discomfort caused by the microsuction procedure. Hearing loss induced by impacted cerumen was also investigated.Design: Impacted cerumen was removed from patients using microsuction. Hearing assessments were carried out before the procedure, immediately after and 1-week later. Hearing thresholds measured in different sessions were compared to determine the TTS caused by the microsuction procedure and hearing loss induced by impacted cerumen. A questionnaire was used to evaluate the pain/discomfort experienced by patients.Study Sample: 30 patients (50 ears) were recruited from a cerumen removal clinic.Results: Significant hearing loss caused by impacted earwax was found across individual frequencies (mean 11.4 dB, maximum 38.1 dB). A TTS appeared in 43/50 (86%) ears, ranging from 0 to 16.2 dB averaged across frequencies between 0.25 and 8 kHz, with the highest TTS at 6 kHz. Pain and discomfort levels were both rated low, the mean levels were 1.2 (SD = 0.5) and 1.6 (SD = 0.5) respectively on a scale from 1 to 10.Conclusions: Microsuction appears to be a well-tolerated and preferred procedure for removing impacted cerumen. Because of the significant TTS induced by the microsuction procedure, safety concerns from a hearing perspective should be raised with the patient.

A Novel Association between the 27-bp Deletion and 538G>A Mutation in the ABCC11 Gene.

A single nucleotide polymorphism in the ABCC11 gene, 538G>A (rs17822931), is known to determine human ear wax type. The G/G and G/A genotypes correspond to the wet type, while the A/A genotype corresponds to the dry type. Another earwax determinant, a 27-bp deletion (Δ27) downstream from the rs17822931 site, is a rare variant that leads to the dry phenotype. In a previous report, we found an individual with the G allele who unexpectedly showed the dry type of earwax, leading to the identification of Δ27. We also demonstrated that the Δ27 allele was present in individuals of Japanese, Thai, native North American, Andean, and Bolivian ancestry but absent in those of European and African ancestry. Here, we assessed the Δ27 allele frequency among Japanese and Ukrainian individuals and identified a novel association between the Δ27 and 538G>A mutations. The Δ27 allele frequency was 0.002 (3/1,520; one individual is heterozygous, and another is homozygous) among Japanese individuals and 0 (0/794) among Ukrainians. We also found a previously unreported homozygous genotype for both the Δ27 and A alleles. Our findings suggest that the Δ27 deletion may have occurred in an ABCC11 gene with the 538G>A mutation.

Evaluation of the safety and efficacy of a novel product for the removal of impacted human cerumen.

BACKGROUND: This open-label study evaluated the safety and efficacy of a novel product for the removal of impacted cerumen in adult patients. METHODS: This was a prospective, single-center, single-arm, self-controlled clinical trial conducted in a community general practice setting. The novel product contains glycolic acid in an otologically-acceptable buffer containing sodium bicarbonate and glycerin and other buffering agents. The product was instilled into the ear canal prior to irrigation with warm water. Severity of cerumen impaction was graded using a 5-point scale. Improvement in tympanic membrane visualization was assessed after instillation and irrigation. RESULTS: A majority (83%, 25/30) of ears showed improvement with one application: with 53% (16/30) totally dissolved and gained 100% TM visualization. Total dissolution was observed in 80% (24/30) of the study ears per the intent-to-treat analysis and 86% (24/28) if irrigation instructions were followed. Most of the ears/participants that had cerumen blockage symptoms experienced significant improvement with the application. Feelings of fullness disappeared in 92% (11/12) of the affected ears; ears itching, 91% (10/11); water trapping or cracking, 78%, and decreased hearing disappeared in 71% (10/14). All (100%, 18) of the participants who completed the application satisfaction assessment were satisfied with the application process in terms of time needed and the overall rinse procedure. Only one mild adverse event (ear pruritis) occurred that was related to application. CONCLUSIONS: The tested cerumen removal product was effective and safe for removing moderate to severe blockage in patients with impacted cerumen. Procedure satisfaction for the product was high. TRIAL REGISTRATION: This trial is registered on http://www.clinicaltrials.gov/. The registration number is NCT02829294. The trial was retrospectively registered on July 8, 2016.

Prevalence of hearing loss among Canadians aged 20 to 79: Audiometric results from the 2012/2013 Canadian Health Measures Survey.

BACKGROUND: In Canada, population-level estimates of hearing loss have been based on self-reported data, yielding estimates of 4% or 5%. Self-reported hearing difficulties may result in underestimates of hearing loss, particularly among people with mild loss and among older adults. DATA AND METHODS: The 2012/2013 Canadian Health Measures Survey (cycle 3) collected audiometric and self-reported data to estimate the prevalence of hearing loss and limitations in a population-based sample of Canadians aged 20 to 79. Weighted frequencies and cross-tabulations were used to calculate measured and self-reported hearing levels by sociodemographic characteristics. All estimates were weighted at the person-level to represent the population. RESULTS: Based on a pure-tone average of four frequencies that are important in speech, 19.2% of Canadians aged 20 to 79 had measured hearing loss in at least one ear; 35.4% had high-frequency hearing loss. These levels exceeded the self-reported estimate of hearing difficulty--3.7%--derived from responses to questions from the Health Utilities Index Mark 3. The prevalence of measured hearing loss rose with age from no more than 10% among people younger than 50 to 65% at ages 70 to 79. Men were more likely than women to have a hearing loss, a difference that emerged around age 60. Canadians with low household income and/or educational attainment were more likely than those in higher income/education households to have a hearing loss. INTERPRETATION: This analysis presents the first population-based audiometric data on the prevalence of hearing loss among the adult household population of Canada, and highlights the disparity between measured and self-reported outcomes.

Simultaneous determination of tramadol in earwax and urine samples: effects of age, duration time and sex.

Background: This study aims to determine the concentrations of tramadol in earwax (µg/g) and urine (µg/ml) samples taken from postoperative patients, to evaluate the sensitivity of earwax (cerumen) as an alternative analyte and compare it with the findings in urine samples. Results: The results indicated that tramadol concentrations in earwax samples were averaged 45.08 µg/g (range: 13.5-107.7 µg/g), whereas tramadol concentrations in urine samples were averaged 4.97 µg/ml (range: 1.57-10.11 µg/ml). There were significant differences when comparing age groups, duration and sex between earwax and urine samples (p < 0.05). Conclusion: Despite the significant differences between earwax and urine samples, earwax can be used as a bioindicator of tramadol detection.

Impact of Reduced Acidic Earwax pH and Earwax-Determinant Genotypes in Acquired Middle Ear Cholesteatoma.

OBJECTIVE: The development of acquired middle ear cholesteatoma is associated with a single nucleotide polymorphism, 538G>A, in the human adenosine triphosphate-binding cassette transporter C11 (ABCC11) gene, which is a determinant of the earwax morphotype, such as wet- and dry-type earwax; however, the mechanism underlying this association is unclear. We focused on the earwax pH and aimed to elucidate the mechanism between ABCC11 genotypes and acquired middle ear cholesteatoma. STUDY DESIGN: Prospective observational study. SETTING: Single-center, academic hospital. METHODS: We recruited 40 patients with acquired middle ear cholesteatoma who underwent surgery and 115 controls with no history of middle ear cholesteatoma. We assessed the earwax pH and ABCC11 genotypes in all participants. Clinical information was collected from the patients with cholesteatoma. RESULTS: The earwax pH was significantly less acidic in patients with cholesteatoma and those carrying wet earwax genotypes (ABCC11 538G/G or 538G/A) than in the controls and those carrying the dry earwax genotype (ABCC11 538A/A), respectively. Furthermore, earwax pH was significantly positively correlated with high preoperative cholesteatoma stages in the patients with cholesteatoma. CONCLUSION: Our results show that the less acidic earwax pH was significantly related to the development and progression of acquired middle ear cholesteatoma. The less acidic earwax pH may play an important role in the mechanism underlying the association between acquired middle ear cholesteatoma and the ABCC11 gene at site 538.

The use of earwax to determine livestock exposure to teratogenic lupine.

Lupines (Lupinus spp.) are a common plant species on western U.S. rangelands with several lupine species containing alkaloids that can be toxic and/or teratogenic to livestock. In North America, more than 150 lupine species are recognized with some ranches or grazing allotments containing multiple species. One or more of these lupine species may contain alkaloids that are teratogenic to cattle. Previous work has shown that lupine alkaloids can be detected in earwax of cattle grazing lupine infested rangelands. Our hypothesis is that earwax can be used to determine if cattle have been exposed to teratogenic alkaloids from multiple lupine species. Two lupine species, L. sericeus and L. polyphyllus, were present on a rangeland in east-central Idaho. The teratogen, anagyrine, was detected in L. sericeus and the teratogen, ammodendrine, was detected in L. polyphyllus plants collected on this rangeland. In this study, earwax was collected from 69 pregnant cows that had previously grazed a rangeland containing two different lupine species containing alkaloids that cause crooked calf syndrome (CCS). Anagyrine was detected in the earwax of all 69 cows sampled. Ammodendrine, was detected in the earwax of 28 of the 69 cows sampled. Earwax is a good non-invasive sample to aid in the diagnosis of cattle that have consumed lupine and does appear, in this case, to be a good diagnostic tool to differentiate between more than one lupine species that may be the cause of CCS. Concentrations of anagyrine or ammodendrine did not correlate with the incidence of CCS.

Cerumen impaction: Prevalence and associated factors in the United States population.

Objective: To examine the prevalence of cerumen impaction in a nationally representative sample of the US population and the association of cerumen impaction with sociodemographic factors, hearing loss, and tinnitus. Methods: The cohort included 14,230 individuals aged ≥12 years who completed otoscopy and audiometry in NHANES (2005-2016). Cerumen impaction (partial/complete) was determined by otoscopy. Hearing level was defined by speech-frequency pure-tone average (PTA). Multivariable regression analysis was performed to identify factors associated with cerumen impaction. Results: The prevalence of any cerumen impaction was 18.6% [95% CI: 17.3%-19.9%] among individuals ≥12 years and 32.4% [29.9%-35.1%] among those ≥70 years. The prevalence of bilateral partial and complete cerumen impaction was 6.3% [5.6%-7.1%] and 1.2% [1.0%-1.9%], respectively. Any cerumen impaction was associated with male sex (OR 1.77 [1.5-2.1]), identifying as Black race (vs. Caucasian, OR: 1.78 [1.5-2.9]), lower level of education (OR: 0.84 [0.71-0.98]), and older age (OR: 1.02 [1.01-1.03]). After adjusting for sociodemographic and clinical factors, complete impaction was associated with increased PTA (right ear: ß = 4.1 dB [2.4-5.8 dB], left ear: ß = 1.9 dB [0.46-3.4 dB]), but not with tinnitus. Conclusions: Cerumen impaction is highly prevalent in the US population, especially among older adults, and has disproportionate sociodemographic impacts. Complete impaction is associated with a small, statistically significant elevation in PTA, but there is no association with tinnitus. These findings emphasize the need to implement and disseminate best practices for ear hygiene and cerumen management broadly and equitably. Level of Evidence: 2B.

Determination of fentanyl and norfentanyl in cerumen in the setting of postmortem investigation.

Cerumen is an emerging alternative biological matrix in the field of forensic toxicology. An ultra-high-pressure liquid chromatography-mass spectrometry/mass spectrometry [UHPLC-MS/MS] method for the determination of fentanyl and norfentanyl in cerumen was developed and applied in a mixed drug toxicity fatal case. The method was found to be selective and sensitive (LOQ: 0.05 ng/mg for fentanyl and 0.02 ng/mg for norfentanyl), while validation included recovery, carryover, short-term stability, matrix effect, accuracy, and precision (RSD%). Accuracy ranged from 83.1% to 103.5%, while intra- and inter-day precision ranged from 8.6% to 13.1% and from 8.3% to 15.8%, respectively. Matrix effect experiments showed that matrix did not significantly affect signal intensity (82.3%-96.8%). Short-term stability concerning sample extracts was found satisfactory. Fentanyl and norfentanyl were detected in cerumen at a concentration of 1.17 and 0.36 ng/mg respectively. The findings in cerumen corroborate the cause of death and suggest that cerumen is a potential specimen for detecting drugs of abuse in forensic cases.

Association Between Earwax-Determinant Genotypes and Acquired Middle Ear Cholesteatoma in a Japanese Population.

OBJECTIVE: A single-nucleotide polymorphism 538G>A in the human ABCC11 gene is a determinant of the earwax morphotype. ABCC11 538GG and GA correspond to wet earwax and 538AA to dry earwax. Despite a putative positive correlation between the frequency of the 538G allele and the prevalence of cholesteatoma, minimal clinical information is currently available. We aimed to evaluate this association between the ABCC11 genotypes and acquired middle ear cholesteatoma. STUDY DESIGN: Case-control study. SETTING: Single-center academic hospital. METHODS: We recruited 67 Japanese patients with acquired middle ear cholesteatoma (cholesteatoma group) and 100 Japanese controls with no history of middle ear cholesteatoma. We assessed the ABCC11 genotypes for all participants. Clinical information was collected from the cholesteatoma group. The genotype data of 104 Japanese people from the 1000 Genomes Project who represent the general population were used. RESULTS: The proportion of participants with ABCC11 538GG or GA was significantly higher in the cholesteatoma group than in the control group or general Japanese population (P < .001). The ABCC11 538G allele frequency was also significantly higher in the cholesteatoma group than in the control group or general Japanese population (P < .001). Multivariate logistic regression analyses revealed a significant association between the ABCC11 genotype and acquired middle ear cholesteatoma (odds ratio, 5.49; 95% CI, 2.61-11.5; P < .001). CONCLUSION: Our results suggest that the ABCC11 genotypes could be associated with the development of acquired middle ear cholesteatoma among Japanese people.

A Novel Earwax Method to Measure Acute and Chronic Glucose Levels.

Diabetes is the fourth cause of death globally. To date, there is not a practical, as well as an accurate sample for reflecting chronic glucose levels. We measured earwax glucose in 37 controls. Participants provided standard serum, glycated hemoglobin (HbA1c) and earwax samples at two time-points, one month apart. The specimens measured baseline fasting glucose, a follow-up postprandial glucose level and a between sample chronic glucose, calculated using the average level on the two occasions. The baseline earwax sample was obtained using a clinical method and the follow-up using a novel self-sampling earwax device. The earwax analytic time was significantly faster using the novel device, in comparison to the clinical use of the syringe. Earwax accurately reflected glucose at both assessments with stronger correlations than HbA1c. Follow-up postprandial concentrations were more significant than their respective fasting baseline concentrations, reflecting differences in fasting and postprandial glycemia and more efficient standardization at follow up. Earwax demonstrated to be more predictable than HbA1c in reflecting systemic fasting, postprandial and long-term glucose levels, and to be less influenced by confounders. Earwax glucose measurements were approximately 60% more predictable than HbA1c in reflecting glycemia over a month. The self-sampling device provided a sample that might accurately reflect chronic glycemia.

Earwax: A potentially useful medium to identify inborn errors of metabolism?

Earwax was investigated as a source to identify patients' different inborn errors of metabolism (IEMs). Acylcarnitines, amino acids, and guanidino metabolites were measured from 28 treated patients with 11 different metabolic disorders including 3 organic acidaemias, 2 fatty acid oxidation defects, 6 amino acid disorders, and 1 peroxisomal abnormality. On the basis of the ratio of different acylcarnitine species relative to free carnitine, isovaleric acidaemia, methylmalonic acidaemia, and long-chain hydroxyacylCoA dehydrogenase deficiency could be discriminated from the other disorders. For amino acids, neither creatinine nor alternative amino acid proved suitable reference standards against which results could be expressed. However, argininosuccinate and alloisoleucine were present in significantly elevated concentrations in two patients with argininosuccinate lyase deficiency and two patients with branched-chain ketoacid dehydrogenase deficiency. This study has raised the potential of earwax for investigation of IEMs and may also have role in postmortem investigations. In view of its limited invasiveness, earwax also may have a role as a material to monitor treatment responses and compliance in patients with IEMs.

Cerumen Management: An Updated Clinical Review and Evidence-Based Approach for Primary Care Physicians.

Objective: To provide family physicians with a practical, evidence-based approach to managing patients with cerumen impaction. Methods: MEDLINE, The Cochrane Library, and the Turning Research Into Practice (TRIP) database were searched for English-language cerumen impaction guidelines and reviews. All such articles published between 1992 and 2018 were reviewed, with most providing level II and III evidence. Results: Cerumen impaction is a common presentation seen in primary care and cerumen removal is one of the most common otolaryngologic procedures performed in general practice. Cerumen impaction is often harmless but can be accompanied by more serious symptoms. Cerumenolytics and irrigation of the ear canal are reasonable first-line therapies and can be used in conjunction or isolation. If irrigation and cerumenolytics are contraindicated, manual removal is appropriate, but the tools necessary are not commonplace in primary care clinics and specialized training may be required to prevent adverse outcomes. Conclusion: Family physicians play a key role in the assessment and management of cerumen impaction and are well equipped to do so. Knowledge of the available techniques for cerumen removal as well as their contraindications ensures that cerumen is removed safely and effectively. When cerumen removal cannot be removed safely in a primary care setting, referral to Otolaryngology-Head and Neck Surgery is appropriate.

Measuring Earwax Cortisol Concentration using a non-stressful sampling method.

BACKGROUND: "Short-term" samples are not the most appropriate for reflecting chronic cortisol concentration. Although hair is used for reflecting the systemic level of this hormone, its use as a "long-term" measure appears clinically problematic. Local and systemic stress and non-stress related factors may release cortisol that is accumulated in hair. Non-stressful earwax sampling methods may provide a more accurate specimen to measure chronic cortisol concentration. METHODS: Earwax from both ears of 37 controls were extracted using a clinical procedure commonly associated with local pain. One month later, earwax from the left ear side was extracted using the same procedure, and earwax from the right ear side was more comfortably obtained, using a novel earwax self-sampling device. Participants also provided one centimetre of hair that represented the retrospective month of cortisol output, and one serum sample that reflected the effect of systemic stressors on cortisol levels. Earwax (ECC), Hair (HCC) and Serum (SCC) Cortisol Concentration were correlated and compared. Confounders' effect on cortisol levels were studied. RESULTS: The highest levels of cortisol concentration were found in serum, and the lowest in hair (p < 0.01). Left-ECC was larger than Right-ECC (p = 0.03). Right-ECC was the only sample unaffected by confounders (all p > 0.05). A Pearson correlation showed that Right-ECC and HCC samples were moderately correlated between them (r = 0.39; p = 0.03). CONCLUSIONS: The self-sampling device did not increase cortisol locally. It provided the cortisol level that was least likely to be affected by confounding factors over the previous month. ECC using the novel device might constitute another accurate, but more suitable and affordable specimen for measuring chronic cortisol concentration.

Hormone comparison between right and left baleen whale earplugs.

Marine animals experience additional stressors as humans continue to industrialize the oceans and as the climate continues to rapidly change. To examine how the environment or humans impact animal stress, many researchers analyse hormones from biological matrices. Scientists have begun to examine hormones in continuously growing biological matrices, such as baleen whale earwax plugs, baleen and pinniped vibrissae. Few of these studies have determined if the hormones in these tissues across the body of the organism are interchangeable. Here, hormone values in the right and left earplugs from the same individual were compared for two reasons: (i) to determine whether right and left earplug hormone values can be used interchangeably and (ii) to assess methods of standardizing hormones in right and left earplugs to control for individuals' naturally varying hormone expressions. We analysed how absolute, baseline-corrected and Z-score normalized hormones performed in reaching these goals. Absolute hormones in the right and left earplugs displayed a positive relationship, while using Z-score normalization was necessary to standardize the variance in hormone expression. After Z-score normalization, it was possible to show that the 95% confidence intervals of the differences in corresponding lamina of the right and left earplugs include zero for both cortisol and progesterone. This indicates that the hormones in corresponding lamina of right and left earplugs are no different from zero. The results of this study reveal that both right and left earplugs from the same baleen whale can be used in hormone analyses after Z-score normalization. This study also shows the importance of Z-score normalization to interpretation of results and methodologies associated with analysing long-term trends using whale earplugs.

Cerumen Impaction Removal in General Practices: A Comparison of Approved Standard Products.

BACKGROUND: Ear irrigation is a commonly used method for removing earwax in general practice. There is no firm evidence if no pre-treatment is as good as pre-treatment with various standard preparations. AIM: To assess the effectiveness of no pre-treatment compared to pre-treatment with commercially available cerumenolytics and to assess which preparation is best suited for pre-treatment. METHODS: This is a pragmatic observational study of patients with cerumen treated from a single GP with 3 different preparations or no preparation prior to standardized ear irrigation. Generalized linear mixed models with logit link function were performed to assess the effectiveness of pre-treatment with different preparations and no pre-treatment. The models were adjusted for age group (<70, ≥70) and sex. RESULTS: A total of 168 patients (298 ears, 58 % female, median age 65 years) consulted for obstructive cerumen, some of them several times. The cerumen was successfully removed in 70% (208/298). Comparing any preparation to no preparation (aggregated comparison), the odds ratio for complete clearance was 1.35 (95%confidence interval: 0.69-2.65). Comparing the preparations individually, the odds ratio of the docusate-sodium-based preparation was 1.87 (95% CI: 0.79-4.42) indicating a higher effectiveness. Although, not statistically significant. Ear irrigation was less successful for patients aged ≥ 70 years (OR = 0.48, 95% CI: 0.23-0.98). CONCLUSIONS: The aggregated comparison indicates a slight trend toward a higher effectiveness of any pre-treatment compared to no pre-treatment. The effect-size of docusate-sodium-based pre-treatment indicates a higher effectiveness of cerumen impaction removal. Nevertheless, superiority could not be shown conclusively according to the statistical significance given the restricted sample size.