Production rate and composition of cerumen: influence of sex and season

The production rate and composition of cerumen have been studied in 11 participants (5 men and 6 women), 25 to 42 years old. The cerumen was obtained in January, May, July, and November to investigate the possible influence of the season. Only the triglyceride content decreased from November to July. Sex was not a factor, which supported the hypothesis that sex hormones play a minor role in the production rate of the lipid component of cerumen.

Do patients with otitis externa produce biochemically different cerumen?

As polyunsaturated fatty acids have better antibacterial properties than saturated fatty acids, the cerumen of seven patients with recurrent otitis externa and seven unaffected subjects was analysed to determine their ratio. There was no significant difference in either the overall ratio of unsaturated/saturated fatty acids or in the amounts of the individual fatty acids from the cerumen of either group.

The origin of alkanes found in human skin surface lipids

Lipids extracted from human skin contain variable amounts of paraffin hydrocarbons. Although the composition of these alkanes strongly resembles petroleum waxes, it has been proposed that they are biosynthetic products of human skin. To investigate this question, skin surface lipids from 15 normal subjects were analyzed for the amount and composition of alkanes, using quantitative thin-layer chromatography and quartz capillary gas chromatography. The alkanes were found to constitute 0.5% to 1.7% of the skin lipids. Subjects differed greatly in the chain length distribution of their alkanes between 15 and 35 carbon atoms, and in the relative amounts of normal alkanes (like those in petroleum waxes) and branched chain alkanes (like those in petroleum lubricating oils). In 6 subjects, the alkane content of cerumen from each ear was examined to investigate whether alkanes arrive at the skin surface by a systemic route or by direct contact with environmental surfaces. No trace of alkanes was found in 11 of the 12 cerumen samples. Using a tandem accelerator mass spectrometer for carbon-14 dating, a combined sample of the skin surface alkanes was found to have a theoretical age of 30,950 years, similar to that of a sample of petrolatum. These analyses indicate that the alkanes found on the surface of human skin are mixtures of a variety of petroleum distillation fractions that are acquired by direct contamination from the environment.

The mechanism of ceruminolysis

In a previous study comparing the efficacy of a selection of commonly used ceruminolytics, the authors noted that aqueous-based preparations, and in particular solutions of sodium bicarbonate, were more effective in disintegrating cerumen than most organic-based preparations. In that study, the authors also observed that not only had the wax truly disintegrated following exposure to the aqueous-based preparations, but also that a marked degree of swelling of the wax spheres had occurred with these preparations. In this paper the mechanism of ceruminolysis was investigated by means of a number of commonly available histological techniques. Our findings show that desquamated sheets of corneocytes are the major constituent of cerumen plugs and provide the structural framework of the wax bolus. Ceruminolytics work by hydrating the keratin cells of these sheets of desquamated stratum corneum and subsequently inducing keratolysis, with disintegration of the wax.

Identification of long-chain fatty acids and alcohols from human cerumen by the use of picolinyl and nicotinate esters

Human cerumen was hydrolysed with base and the constituents were examined as trimethylsilyl (TMS), methyl ester/TMS, picolinyl/TMS and nicotinate/TMS derivatives by gas chromatography and gas chromatography/mass spectrometry. A sample was also reacted with osmium tetroxide for double bond location. The major constituents were cholesterol, squalene and several series of long-chain fatty acids and alcohols. These latter compounds had chain lengths of 12-26 carbon atoms and were predominantly either straight-chain saturated or straight-chain unsaturated compounds. Saturated branched-chain acids with methyl groups predominantly on even-numbered carbon atoms were present but were less abundant. Unsaturated, branched-chain acids were also present. The major unsaturated acids contained unsaturation at the delta-6-position or were derived from these acids by chain elongation. The compounds were similar to those found in vernix caseosa. The mass spectra of picolinyl esters were, for the first time, shown to be capable of determining both the position of unsaturation and methyl branching in the same molecule.

Dermatophytosis of the external auditory meatus

Thirty-two cases of dermatophyte infection in the external auditory meatus are reported. All the patients complained of slight itching or accumulation of cerumen; however, they had no other serious complaints. Otoscopy revealed lesions in the outer third of the ear canal. The skin of the meatus externus osseus and the surface of the tympanic membrane were all intact. In all cases, mycelial elements were demonstrated in KOH mounts of scrapings, and Trichophyton rubrum (29 cases), Microsporum canis (2 cases), and Epidermophyton floccosum (1 case) were isolated. All patients had ringworm of the pinna at the time of examination or in the past.

A technique for measuring the rate of cerumen production

A technique is described for quantitatively measuring the rate of cerumen production. Two different washing solutions were tried. A mixture of alcohol/ether (3:1 v/v) appeared to be the best extracting solution yielding 2.05 +/- 0.22 versus 0.73 +/- 0.14 mg/week per ear obtained with Triton X-100 solution. In addition, reproducibility was definitely better. Triton X-100 may be useful whenever microbiologic evaluations are requested. Total lipids accounted for 73.3% of cerumen extracted with the former solution, triglycerides being 19.5%, and cholesterol 7.2%. Our extracting technique appears to be a good estimate of the cerumen global output and may supply important information about cerumen in several biologic conditions.

Characterization of 2,7-anhydro-N-acetylneuraminic acid in human wet cerumen

A molecular species of sialic acid was isolated in a free form from cerumen of the wet type, but not of the dry type, by an ion-exchange column chromatography and preparative high-performance liquid chromatography. Structural analysis of this sialic acid was performed by gas-liquid chromatography/mass spectrometry with chemical ionization (CI) and electron ionization (EI). In the CI mass spectra, the protonated molecular ion of the trimethylsilyl derivative was observed at m/z 580. and that of the methyl ester-trimethylsilyl derivative was at m/z 522. In the EI mass spectrum, the methyl ester-trimethylsilyl derivative gave characteristic ions at m/z 506, 462, 418, 416, 328, 316, 238, 228, 205, 186, and 173. This mass spectrum was identical with that of 2,7-anhydro-N-acetylneuraminic acid, which was reported by Lifely and Cottee (Carbohydr. Res. 107, 187-197, 1982) as the mass spectrum of a by-product prepared from N-acetylneuraminic acid by methanolysis. These results indicate that the compound in the wet cerumen is 2,7-anhydro-N-acetylneuraminic acid. Since this sialic acid species could not be detected in cerumens of the dry type, its formation in the wet type may be controlled by an autosomal dominant gene.

Epidemiology of breast fluid secretion: association with breast cancer risk factors and cerumen type

The epidemiology of breast fluid secretion was studied on the basis of nipple aspirates of breast fluid obtained from 3,929 nonlactating women of various racial groups. The results confirmed and extended earlier findings by our group: Variation in the proportion of secretors was related to most breast cancer risk factors, including age, race, age at menarche, age at first pregnancy, age at menopause, clinically diagnosed fibrocystic disease, menopausal estrogen use, and cerumen phenotype. Secretory activity as measured by nipple aspiration appeared to reflect hormonal and genetic effects on breast epithelium.

Physical variation in three Assamese castes

The paper deals with variation with regard to certain physical traits like AB0 blood groups, cerumen type, cross section of head hair, finger patterns and anthropometric characters in three Assamese caste populations, namely Brahmin, Kalita and Kaibarta representing three strata of the Assamese caste society. The study reveals that in respect of AB0 blood groups, cerumen type and finger patterns the Kaibartas stand apart from the Brahmin and Kalita, who are similar to one another. With regard to the other traits a different picture is observed. When the castes are arranged in hierarcheal order, the hair becomes coarser from the Brahmin to the Kaibarta through the Kalita. The metric values also can be arranged in a similar manner when certain values show a decrease from the lower to higher caste and others increase. While dealing with the nature of variation an attempt has also been made to look for the possible reasons. It appears that a host of factors like ethnic migration, inflow of genes, isolation are involved to cause variation.

Genetic markers and cancer epidemiology

The study of potential associations between genetic markers and various cancers has a long history in cancer epidemiology. Such investigations are subject to serious problems of statistical significance and the choice of appropriate control populations. A promising future for the use of human population genetics in cancer epidemiology may be in the investigation of genetic markers (such as the HL-A complex) which code for proteins of potential immunological or physiological importance in susceptibility or resistance to cancer. The cerumen gentic marker has played a central part in a hypothesis formulated in our laboratory for the etiology of breast cancer. A second new development in this field is likely to be the investigation of genetic markers in families with high incidence of cancer. Such families permit the simultaneous study of genetic hypotheses of cancer inheritance and the association of marker genotypes with cancer through segregation and linkage analysis.

Genetic markers and cancer epidemiology

The study of potential associations between genetic markers and various cancers has a long history in cancer epidemiology. Such investigations are subject to serious problems of statistical significance and the choice of appropriate control populations. A promising future for the use of human population genetics in cancer epidemiology may be in the investigation of genetic markers (such as the HL-A complex) which code for proteins of potential immunological or physiological importance in susceptibility or resistance to cancer. The cerumen gentic marker has played a central part in a hypothesis formulated in our laboratory for the etiology of breast cancer. A second new development in this field is likely to be the investigation of genetic markers in families with high incidence of cancer. Such families permit the simultaneous study of genetic hypotheses of cancer inheritance and the association of marker genotypes with cancer through segregation and linkage analysis.

Hidradenomata of the external auditory meatus. (Review of the literature and report of a pleomorphic adenoma)

A case of hidradenoma of the external auditory meatus ('ceruminoma') is presented, with a review of the literature. The tumour has the appearances of a pleomorphic adenoma and is devoid of a capsule. It is suggested that the term hidradenoma be used for tumours of the ceruminous glands and that they be classified histologically as (1) adenoma, (2) pleomorphic adenoma, (3) adenoid cystic carcinoma and (4) adenocarcinoma. This classification aids treatment and prognosis. Attention is drawn to the high incidence of malignancy in hidradenomata of the external auditory meatus. The treatment of choice for pleomorphic adenomata is wide surgical excision with an adequate margin of normal skin. If there is doubt regarding complete removal, or a recurrence develops, a wider surgical excision is necessitated.

Cerumen types in Choctaw Indians

Certinen from 432 Choctaw Indians from Mississippi was classified as sticky or dry. The frequency of the autosomal recessive dry type was intermediate between that for Indians of western North America and that for Mayan groups of southern Mexico.