[A rare pathology of the petrous part of the temporal bone: adenoma of the middle ear]

Adenomas are very rare tumors of the middle ear. They are benign neoplasms originating from the glandular components of the mucous membrane of the middle ear. The middle ear adenoma was first described by Hyams and Michaels in 1976, which was named an adenomatous tumor. This article reports the case of a 50-year-old female patient, who presented with recurrent right-sided dull otalgia and pulse synchronous tinnitis, which began 1 year prior to presentation, with the suspected diagnosis of a glomus tympanicum tumor. Following the otorhinolaryngological examination and imaging an unclear mesotympanal space-occupying lesion was detected. A transmeatal endoscopic complete removal of the tumor was carried out. The histopathological investigations enabled the diagnosis of an adenoma of the middle ear. Adenomas are a rare differential diagnosis of tumors of the middle ear. In cases with a suitable localization an adequate exposure and removal of this rare tumor can be achieved by a transmeatal endoscopic access.

Distinct Heritable Influences Underpin In-Group Love and Out-Group Derogation

In-group favoritism has often been conceptualized as the flip side of out-group derogation. Whereas research has dissociated these attitudes at the phenotypic level, it is currently unknown whether such dissociation is also evident at the biological level. Here, using an adult German twin sample, which provided ratings on patriotism, nationalism, and prejudice, we tested whether common or distinct heritable influences best explained variation in in-group love and out-group derogation. Results indicated that independent genetic effects accounted for individual differences in in-group love (i.e., patriotism) and out-group derogation (i.e., prejudice). In addition, we observed that nationalism showed common genetic links to both patriotism and prejudice, albeit through distinct pathways. These findings suggest that in-group sentiment is complex at the genetic level as well as at the behavioral level. Future work is recommended to further delineate the specific biological processes underlying these heritable effects.

[Value of informed consent in tympanoplasty and FESS procedures]

BACKGROUND

More than one third of all lawsuits against surgeons include statements of insufficient or lacking preoperative informed consent which is mandatory in the german jurisprudence. Almost nothing is known about the postoperative patient's memory of risk factors which were explained prior to typical surgical procedures in ENT.

METHODS

The objectives of this prospective study in 201 patients were to elucidate the actual clinical routine of obtaining informed consent for tympanoplasty (n=105) and FESS procedures (n=89), collect information on active and passive recall 6 weeks, 6 months and 1 year post-operatively, and to investigate whether patient age, sex, education, the time from obtaining consent to interview, recurrent vs. non-recurrent procedures, would influence the patient's recall capabilities.

RESULTS

In clinical routine, obtaining informed consent included 5 main items for tympanoplasty and 5 for FESS procedures made by the physician. Of the patients, 18.9% recalled actively and 65.3% passively. They named 1.5 items on average, with "deafness" as the leading complication in tympanoplasty and "amaurosis" in FESS procedures. Patient's memory was depending on the time from obtaining consent to interview and education exclusively.

CONCLUSION

In conclusion, the quantity of patient/physician interaction does not guarantee an increased effect on patient's recall. Improving patient interaction may reduce the probability of imminent accusations.

[Skin prick test results in snoring and sleep apnea patients]

BACKGROUND

In allergic rhinitis, nasal obstruction is a typical symptom. Reduced nasal ventilation is thought to be one causal factor for sleep breathing disorders. Whether or not snoring individuals with or without sleep apnea show more frequent or stronger reactions in skin prick tests (SPT) compared to non-snorers has not been investigated yet.

METHOD

SPT on 20 most frequent allergens and standardized questionnaires of 412 patients of either sex who received a polysomnography at the sleeplab of the ENT department, University of Würzburg, Germany, were analysed retrospectively. In 351 patients (85 %), data were complete. According to their polysomnography, patients were grouped into snorers (n = 248, 71 %) and non-snorers (n = 103, 29 %) or apnea (apnea-hypopnea-index > 10; n = 171, 49 %) and non-apnea patients (n = 180, 51 %). Average occurrence or strength of skin reactions was compared between these groups.

RESULTS

Except plantain (7 % vs. 1 %) and beech (10 % vs. 3 %), there were no statistical increases in the average occurrence or strength of SPT results in snoring individuals. Apnea patients did not show more frequent or stronger allergic skin reactions than non-apnea patients. Three patients suffering from allergic rhinitis by house dust mites were treated with citerizin 10 mg and allergen exposition prophylaxis. Three months after onset of therapy in all three patients, a reduction of snoring was polysomnographically observed. Snorers or apnea patients complaining sneezing, reduced nasal ventilation at night, hyperlacrimation or rhinorrhea showed significant higher numbers of allergic skin reactions for rye, gras and house dust mites compared to patients without these symptoms.

CONCLUSIONS

The results reveal that only snorers or apnea patients with specific symptoms for allergic rhinitis should be tested by SPT. A general SPT-screening seems not to be indicated. Snoring and apneas in patients with allergic rhinitis due to house dust mites can be eliminated or reduced by an oral antihistaminic treatment.

Combined intra-operative monitoring of hearing by means of auditory brainstem responses (ABR) and transtympanic electrocochleography (ECochG) during surgery of intra- and extrameatal acoustic neurinomas

BACKGROUND

Although being established as a standard procedure in intra-operative monitoring in acoustic neurinoma surgery, auditory brainstem responses (ABR) represent a far-field technique bearing some technical limitations. This prospective study was designed to evaluate electrocochleography (ECochG) as a supplementary tool for hearing preservation.

METHOD

84 patients with unilateral intra-/extrameatal acoustic neurinomas (extrameatal diameter: 5-55 mm) preserving serviceable hearing, were operated on using a combined (neuro-/otosurgical) suboccipital approach. ECochG was recorded simultaneously to ABR following transtympanic insertion of a steel needle electrode into the promontory under otoscopic view.

FINDINGS

Serviceable hearing (Class 1-3 according to Gardner/Robertson) was preserved in 43 out of 84 patients (51.2%), of whom 40 showed both ECochG and ABR being preserved. All 24 patients with loss of both modalities became deaf. Hearing preservation was observed in 4 out of 12 patients with preserved ECochG but loss of ABR (waves III-V). The reverse was observed in 2 cases with postoperative deafness. While both ECochG and ABR amplitudes were significantly correlated with pre- and postoperative hearing, latencies of ECochG summating (SP) and action potential (AP) proved to be more reliable indicators for preserved hearing than ABR (peak I/III/V) latencies. The predictive value of baseline ABR amplitudes for postoperative hearing, however, was superior to ECochG parameters. Only in large neurinomas (extrameatal diameter: >2 cm) tumour size was found to be a significant predictor for the preservation of hearing. Apart from three cases with postoperative otoliquorrhea and one further case presenting with local bleeding within the external acoustic meatus, no side effects were observed.

CONCLUSIONS

In combination with ABR monitoring, ECochG proved to be a useful supplementary tool for hearing preservation in acoustic neurinoma surgery. It is particularly helpful during electrocautery and drilling, since no averaging is required. Special applications are: (1) small tumours with good serviceable hearing; (2) and/or a large intrameatal portion; (3) cases with lost or endangered contralateral hearing (e.g. bilateral acoustic neurinomas), when the preservation of poor or even non-functional hearing is desirable.

Covariance structure of neuroticism and agreeableness: a twin and molecular genetic analysis of the role of the serotonin transporter gene

The Revised NEO Personality Inventory domains of Neuroticism and Agreeableness are considered factorially distinct despite several intercorrelations between these domains. The genetic correlation, an index of the degree to which these intercorrelations are caused by genetic influences, was estimated using data from 913 monozygotic and 562 dizygotic volunteer twin pairs from Canada, Germany, and Japan. The serotonin transporter gene, 5-HTTLPR, was assayed in a sample of 388 nontwin sibling pairs from the United States to determine the contribution of the serotonin transporter locus to the covariation between the Neuroticism and Agreeableness scales. In all four samples, genetic influences contributed to the covariance of Neuroticism and Agreeableness, with the serotonin transporter gene accounting for 10% of the relationship between these domains.

Sources of structure: genetic, environmental, and artifactual influences on the covariation of personality traits

The phenotypic structure of personality traits has been well described, but it has not yet been explained causally. Behavior genetic covariance analyses can identify the underlying causes of phenotypic structure; previous behavior genetic research has suggested that the effects from both genetic and nonshared environmental influences mirror the phenotype. However, nonshared environmental effects are usually estimated as a residualterm that may also include systematic bias, such as that introduced by implicit personality theory. To reduce that bias, we supplemented data from Canadian and German twin studies with cross-observer correlations on the Revised NEO Personality Inventory. The hypothesized five-factor structure was found in both the phenotypic and genetic/familial covariances. When the residual covariance was decomposed into true nonshared environmental influences and method bias, only the latter showed the five-factor structure. True nonshared environmental influences are not structured as genetic influences are, although there was some suggestion that they do affect two personality dimensions, Conscientiousness and Love. These data reaffirm the value of behavior genetic analyses for research on the underlying causes of personality traits.

Genetic and environmental influences on observed personality: evidence from the German Observational Study of Adult Twins

Previous behavior-genetic research on adult personality relied primarily on self-reports or peer reports that may be subject to contrast effects, resulting in biased estimates of genetic and environmental influences. In the German Observational Study of Adult Twins (GOSAT), personality traits of 168 monozygotic (MZ) and 132 dizygotic (DZ) twin pairs were rated on 35 adjective scales, largely markers of the Big 5. The ratings were provided by 120 judges who never met the twins but observed videotaped behaviors of 1 twin of each pair in 1 of 15 different settings. The aggregated video-based trait ratings were highly reliable, and substantial correlations were obtained between MZ as well as DZ twins. Model-fit analyses suggested about 40% genetic, 25% shared environmental, and 35% nonshared environmental influence. Extraversion was the only trait that seemed not to be influenced by shared environment.

Distribution and projections of nitric oxide synthase neurons in the rodent superior olivary complex

The superior olivary complex (SOC), a group of interrelated brainstem nuclei, sends efferents to a variety of neuronal structures including the cochlea and the inferior colliculus. The present review describes data obtained from rodents providing evidence that the gaseous, short-living neuroactive substance nitric oxide (NO) is produced in the SOC. The NO-synthesizing enzyme neuronal NO-synthase (nNOS) has been localized by means of several methods including histochemistry and immunohistochemistry. Perikarya containing nNOS were found in several nuclei of the SOC. Their largest numbers and percentages of total cells were observed in the medial nucleus of the trapezoid body. Stained terminals were observed mainly in the lateral superior olivary nucleus and in the superior paraolivary nucleus. While retrograde neuronal tracing identified a considerable number of nNOS-immunoreactive neurons as to be part of the olivo-cochlear pathway, the projection patterns of other nNOS-immunoreactive SOC cell groups remain to be investigated. We also review other putative sources of cochlear NO, and discuss the possible role of NO in the lower auditory brainstem and organ of Corti with regard to physiological and pathophysiological mechanisms.

Injections of botulinum toxin A into the salivary glands improve sialorrhoea in amyotrophic lateral sclerosis

Sialorrhoea is a socially disabling problem in bulbar amyotrophic lateral sclerosis (ALS). Botulinum toxin A (BoNT/A) was injected into the salivary glands in five patients with bulbar ALS and sialorrhoea. The effect of BoNT/A was measured by the number of paper handkerchiefs used each day and by salivary gland scintigraphy. BoNT/A ameliorated sialorrhoea and quality of life without major adverse effects. BoNT/A may be a relatively safe and effective treatment for sialorrhoea in selected patients.

On the invalidity of validity scales: evidence from self-reports and observer ratings in volunteer samples

Because of the potential for bias and error in questionnaire responding, many personality inventories include validity scales intended to correct biased scores or identify invalid protocols. The authors evaluated the utility of several types of validity scales in a volunteer sample of 72 men and 106 women who completed the Revised NEO Personality Inventory (NEO-PI-R; P. T. Costa & R. R. McCrae, 1992) and the Multidimensional Personality Questionnaire (MPQ; A. Tellegen, 1978/1982) and were rated by 2 acquaintances on the observer form of the NEO-PI-R. Analyses indicated that the validity indexes lacked utility in this sample. A partial replication (N = 1,728) also failed to find consistent support for the use of validity scales. The authors illustrate the use of informant ratings in assessing protocol validity and argue that psychological assessors should limit their use of validity scales and seek instead to improve the quality of personality assessments.

On the invalidity of validity scales: evidence from self-reports and observer ratings in volunteer samples

Because of the potential for bias and error in questionnaire responding, many personality inventories include validity scales intended to correct biased scores or identify invalid protocols. The authors evaluated the utility of several types of validity scales in a volunteer sample of 72 men and 106 women who completed the Revised NEO Personality Inventory (NEO-PI-R; P. T. Costa & R. R. McCrae, 1992) and the Multidimensional Personality Questionnaire (MPQ; A. Tellegen, 1978/1982) and were rated by 2 acquaintances on the observer form of the NEO-PI-R. Analyses indicated that the validity indexes lacked utility in this sample. A partial replication (N = 1,728) also failed to find consistent support for the use of validity scales. The authors illustrate the use of informant ratings in assessing protocol validity and argue that psychological assessors should limit their use of validity scales and seek instead to improve the quality of personality assessments.

Evidence for increased nitric oxide production in the auditory brain stem of the aged dwarf hamster (Phodopus sungorus): an NADPH-diaphorase histochemical study

Age-related changes of the auditory system such as presbyacusis are believed to be due, at least in part, to alterations of central structures. The superior olivary complex (SOC), a group of interrelated brain stem nuclei, projects to a variety of neuronal structures including the cochlea and the inferior colliculus (IC). The soluble gas nitric oxide (NO), believed to function as a neuroactive substance within the SOC and cochlea, is thought to be involved in ageing processes. Since it is unknown whether NO-production is altered in the ageing auditory system, the present study was conducted to investigate whether the number of NO-producing cells in the SOC is changed with increasing age. The histochemical detection of NADPH-diaphorase activity (NADPH-d), a marker for neurons containing NOS, was utilized to investigate the numbers of NO-producing cells in the SOC of adult and senile Djungarian dwarf hamsters (Phodopus sungorus). Our results demonstrate that the number of stained neurons was almost doubled in the SOC of senile hamsters. The most distinct changes were observed in the medial nucleus of the trapezoid body. In contrast, NO-producing preganglionic sympathetic neurons of the spinal intermediolateral nucleus, which was studied for comparison, did not exhibit significant differences between adult and senile animals. It is concluded that the increase of NO-production in the ageing auditory brain stem, as revealed by our data, may be related to hearing impairments with increasing age.

Successful treatment of crocodile tears by injection of botulinum toxin into the lacrimal gland: a case report

OBJECTIVE

Pathologic lacrimation (crocodile tears) is a rare but stigmatizing symptom after facial nerve paralysis. The aim of this pilot study was to examine whether botulinum toxin injection into the lacrimal gland is effective in reducing pathologic tear secretion.

DESIGN

Case report.

INTERVENTION

One patient who had crocodile tears after a zoster oticus infection received a botulinum toxin injection (2.5 mouse units) into the lacrimal gland.

TESTING

Before injection, 1 week, 1 month, and 6 months after injection, patient's lacrimation was assessed by a Schirmer test.

RESULTS

The lacrimation of the injected eye was reduced after 1 week and equal after 1 month when compared to the healthy side. After 6 months, hyperlacrimation reoccurred. No side effects were observed.

CONCLUSION

Intraglandular injection of botulinum toxin into the lacrimal gland may serve as a sufficient therapy for crocodile tears.

Nitric oxide synthase in identified olivocochlear projection neurons in rat and guinea pig

Nitric oxide (NO) is thought to be involved in the effects of amino acids at the level of cochlear hair cell afferents. Recently, the isoform of the NO-producing enzyme, neuronal NO synthase (nNOS), has been demonstrated in neuronal structures of the cochlea in rats and guinea pigs histochemically and immunohistochemically. To investigate the sources of cochlear NO, we injected Fluoro-Gold (FG) into the cochlea of rats and guinea pigs. Upon terminal uptake of the tracer and neuronal transport we observed FG in terminals at the base of inner (IHC) and outer hair cells (OHC) and in neurons of the spiral ganglion. Ganglion cells and terminals at the IHC were clearly nNOS-positive, while terminals at the OHC exhibited nNOS-immunoreactivity to a minor degree. The immunohistochemical investigation of the auditory brainstem showed that about one-fourth of the neurons of the superior olivary complex contained nNOS. The comparison with retrogradely labeled neurons showed that perikarya in the lateral superior olivary nucleus and, in particular, the medial nucleus of the trapezoid body were double-labeled. These results were similar in both, rat and guinea pig. Our data reveal that neurons of the superior olivary complex are likely to be additional sources of neuronal NOS in the cochlea.

Nitric oxide synthase in trigeminal ganglion cells projecting to the cochlea of rat and guinea pig

Nitric oxide (NO) influences electrophysiological and morphological parameters of the mammalian cochlea. Recently, the isoform of the NO-producing enzyme neuronal NO synthase (nNOS) has been demonstrated in spiral ganglion cells and olivocochlear neurons. The cochlea is also innervated by fibers stemming from the trigeminal ganglion (TG) and superior cervical ganglion (SCG). Whether these ganglion cells contain nNOS is not known yet. We therefore identified TG and SCG cells upon injection of Fluoro-Gold (FG) into the cochlea and retrograde neuronal transport of FG in rat and guinea pig. These ganglion cells were investigated for neuronal NOS immunohistochemically. Perikarya labeled by FG were found in the ipsilateral TG and SCG. In both species investigated, a considerable number of FG-labeled TG cells were also nNOS-immunoreactive whereas SCG cells were not. These data, demonstrating the existence of nNOS-containing TG cells that project to the cochlea, provide evidence that these neurons are further sources of nitric oxide in the cochlea.

Immunfluorescence study of neuropeptides in identified neurons of the rat auditory superior olivary complex

The present study was conducted to investigate the distribution and immunohistochemical characteristics of ascending and descending projection neurons of the rat superior olivary complex (SOC), a group of interrelated brainstem nuclei. Ascending neurons were identified by injection of cholera toxin B subunit (CTB) into the central nucleus of the inferior colliculus (IC), descending neurons were labeled by application of Fluoro-Gold (FG) into the scala tympani of the cochlea, ipsilaterally to the IC injection. In accordance with the literature, we observed neurons innervating the IC located in the lateral superior olivary nucleus (LSO) and dorsal periolivary groups (DPO) on both sides, in the superior paraolivary nucleus (SPO) predominantly ipsilateral, as well as in the ipsilateral medial superior olivary nucleus (MSO) and the medial nucleus of the trapezoid body (MNTB). Cochlear projection neurons were found predominantly in the ipsilateral LSO as well as in the bilateral SPO, DPO, MSO and MNTB. In addition, a considerable population of neurons in the ipsilateral LSO and SPO were identified as being both ascending and descending. To further characterize these double-projecting neurons, brainstem sections were incubated in antisera directed against different neuroactive substances. The majority of ascending/descending cells in the LSO contained calcitonin gene-related peptide, but not substance P (SP), met-enkephalin (ENK) or tyrosine hydroxylase (TH). Some of these neurons apparently were contacted by ENK- or SP-immunoreactive fibers and terminals. In addition, we found TH-immunoreactive neurons in the lateral MNTB region. These neurons, which were labeled upon tracer injection into the cochlea (but not upon IC injection), probably belong to the C1 catecholaminergic cell group and may represent a division of the uncrossed olivocochlear bundle. The present results reveal the existence of a previously unknown subpopulation of SOC neurons that project to both the cochlea and the inferior colliculus. Their CGRP immunoreactivity and their uncrossed projection pattern provide evidence that they may belong to the cholinergic, putatively excitatory cell group.

[Clinical and electrophysiologic studies of facial nerve function after hypoglossal-facial nerve anastomosis]

BACKGROUND

The functional and cosmetic results after hypoglossal-facial nerve anastomosis (HFA) have primarily been described using a subjective grading system of good, fair, or poor. To obtain more objective results, the postoperative mimic function was investigated using a combination of clinical and electrophysiological methods.

METHODS

A total of 29 patients with hypoglossal-facial anastomosis were evaluated using a standardized questionnaire and the Stennert's paralysis index as clinical scoring system and electroneurography (NMG/ENoG) and electromyography (EMG) as electrophysiological assessments.

RESULTS

Twenty-six of 29 patients (89%) judged their own facial function as very good or good, and three as poor. Under resting tone conditions, no patient showed a difference between palpebral fissures (> 3 mm), an ectropium, a substantial loss of nasolabial fold, or a drop of angulus oris (> 3 mm). With attempted movement, the lid closure was complete in 76% of patients, and the cornea was lid-covered in 100%. Sixty-seven percent of the patients were able to whistle. The second upper incisor was visible (full width) in 19%. No patient could frown sufficiently or expose the upper and lower canine teeth. The mean Stennert's score decreased from 9 to 4 after surgery. The relative amplitudes of the NMGs were increased in patients with low clinical indices. Patients with a complete eye closure showed a higher density of EMG patterns in their orbicularis oculi muscles. No significant differences for clinical or electrophysiological parameters could be observed based on age, sex, or time point of operation.

CONCLUSION

Combining the Stennert's paralysis index with NMG and EMG allows a more objective assessment of functional and cosmetic results after HFA.

Technical developments in intra-operative monitoring for the preservation of cranial motor nerves and hearing in skull base surgery

Although EMG recordings from mimic muscles have become the standard for intra-operative facial nerve monitoring, few data are available concerning other motor cranial nerves (MCN). Auditory brainstem responses (ABR) are a proven tool for intra-operative hearing preservation, but have their limitations, suggesting the application of supplementary methods. This paper describes new developments of MCN and cochlear nerve monitoring in skull base surgery. Up to 2 x 8 EMG channels were recorded after bipolar stimulation of MCN using concentric coaxial probes. A special software enabled event-dependent registrations of all signals exceeding a definable threshold level. Selective recordings from masticatory muscles (N.V) were obtained using rectangular Teflon-insulated needle electrodes. For oculomotor (Nn.III/ VI) nerve recordings bipolar needle electrodes were precisely placed by orbital ultrasound guidance. Lower cranial nerves were monitored inserting needle electrodes into the soft palate (N.IX), tongue (N.XII) and vocal muscles (N.X) during laryngoscopy using a special applicator. For ABR recordings, click stimuli (95 dB HL) were applied monaurally through insert earphones. Electrocochleography was simultaneously recorded as a near-field potential without averaging after promontory (transtympanic) electrode placement using otomicroscopy. Regarding the ABR biosignal, a characteristic response pattern was detected following bipolar electrical stimulation of the auditory nerve possibly useful for its intra-operative identification.

[Interesting case no. 20--corpus alienum colli]

We report about a 39-year-old man who presented at the department of ENT Würzburg suffering from a suspicious abscess or tumor of the right neck. Computed tomography and X-ray of the neck did not clarify the entity of the process sufficiently. The emergency surgical exploration of the neck showed an unexpected result: a compress which was forgotten during strumectomy 20 years ago.

Projection neurons in the superior olivary complex of the rat auditory brainstem: a double retrograde tracing study

The superior olivary complex (SOC), a group of interrelated brainstem nuclei, sends efferents to a variety of neuronal structures including the cochlea and the inferior colliculus (IC). In the present study conducted in rats, we sought to investigate whether single SOC efferent neurons project to both cochlea and IC. These neurons were identified by retrograde axonal transport of the neuronal tracers fluoro-gold upon application to the cochlea and cholera toxin B subunit injected into the central nucleus of the IC. Projections to the cochlea were found to stem predominantly from the ipsilateral lateral superior olive (LSO) and medial superior olive (MSO) as well as from the bilateral superior paraolivary nucleus (SPO), dorsal periolivary groups (DPO) and the medial nucleus of the trapezoid body (MNTB). Neurons innervating the IC were seen in the bilateral LSO and DPO, in the SPO predominantly ipsilateral, as well as in the ipsilateral MSO and MNTB. We further observed that some neurons in the ipsilateral LSO, and a considerable part of those of the SPO were double-labeled. However, cells projecting to either IC or cochlea were much more numerous than double-labeled neurons.

Heritability of facet-level traits in a cross-cultural twin sample: support for a hierarchical model of personality

The common variance among personality traits can be summarized in the factors of the five-factor model, which are known to be heritable. This study examined heritability of the residual specific variance in facet-level traits from the Revised NEO Personality Inventory. Analyses of raw and residual facet scales across Canadian (183 monozygotic [MZ] and 175 dizogotic [DZ] pairs) and German (435 MZ and 205 DZ pairs) twin samples showed genetic and environmental influences of the same type and magnitude across the 2 samples for most facets. Additive genetic effects accounted for 25% to 65% of the reliable specific variance. Results provide strong support for hierarchical models of personality that posit a large number of narrow traits in addition to a few broader trait factors or domains. Facet-level traits are not simply exemplars of the broad factors they define; they are discrete constructs with their own heritable and thus biological basis.

Heritability of facet-level traits in a cross-cultural twin sample: support for a hierarchical model of personality

The common variance among personality traits can be summarized in the factors of the five-factor model, which are known to be heritable. This study examined heritability of the residual specific variance in facet-level traits from the Revised NEO Personality Inventory. Analyses of raw and residual facet scales across Canadian (183 monozygotic [MZ] and 175 dizogotic [DZ] pairs) and German (435 MZ and 205 DZ pairs) twin samples showed genetic and environmental influences of the same type and magnitude across the 2 samples for most facets. Additive genetic effects accounted for 25% to 65% of the reliable specific variance. Results provide strong support for hierarchical models of personality that posit a large number of narrow traits in addition to a few broader trait factors or domains. Facet-level traits are not simply exemplars of the broad factors they define; they are discrete constructs with their own heritable and thus biological basis.

The serotonin transporter gene and peer-rated neuroticism

Polymorphisms in the serotonin transporter gene (5HTT) have been reported to be associated with neuroticism (emotionality) and with depression. A recent report of an association between 5HTT and neuroticism involved unselected samples and self-report questionnaires. We attempted to extend these findings using a selected extremes design and peer ratings. From a sample of 2085 individuals, each assessed on neuroticism by two independent peers, we selected 52 individuals from the top 5% and 54 individuals from the bottom 5%. No association was found for either a functional 44 bp insertion/deletion polymorphism in 5HTT regulatory sequence (5HTTLPR) or for a non-functional variable number tandem repeat 5HTT polymorphism.

Dust Measurements at High Ecliptic Latitudes

Along Ulysses' path from Jupiter to the south ecliptic pole, the onboard dust detector measured a dust impact rate that varied slowly from 0.2 to 0.5 impacts per day. The dominant component of the dust flux arrived from an ecliptic latitude and longitude of 100 + 10 degrees and 280 degrees +/- 30 degrees which indicates an interstellar origin. An additional flux of small particles, which do not come from the interstellar direction and are unlikely to be zodiacal dust grains, appeared south of -45 degrees latitude. One explanation is that these particles are beta-meteoroids accelerated away from the sun by radiation pressure and electromagnetic forces.