Auto-inflammatory challenge of the endolymphatic sac – Cochlear damage measured by distortion product oto-acoustic emissions

Conclusion: Twenty-five rats were challenged by an immunologic attack of the endolymphatic sac. After 6 months, distortion product oto-acoustic emissions (DPOAE) revealed a dysfunction of the outer hair cells and immunological active cells were observed in the endolymphatic sac. This information could contribute to the understanding of Ménière’s disease. Objectives: This study investigated if an autoimmune challenge of the endolymphatic sac could affect DPOAE output measurements in rats. Also, a potential autoimmune cell infiltration of the endolymphatic sac was investigated. Methods: Eighteen Lewis rats were immunized with a crude endolymphatic sac extract in complete Freund’s adjuvant. Seven control animals were injected with Freund’s adjuvant in saline. Cochlear damage was estimated by DPOAE dynamics 3 weeks and 6 months after the immunization. Infiltrative cells in the endolymphatic sac were investigated with transmission electron microscopy. Results: The hearing assessment 6 months after immunization revealed a reduction of the DPOAE, on the full range of frequencies (2–63 kHz) in an average of the mean, of 2 dB ± 1.1 in the immunized group compared to the controls (p < 0.05). The same test showed a 2.5 dB decrease from 2 to 5 kHz (p < 0.01). Immunological active cells were observed in the endolymphatic sac in most of the immunized rats.     

Characteristics of patients frequently subjected to pharmacological and mechanical restraint—A register study in three Norwegian acute psychiatric wards

This retrospective study from three catchment-area-based acute psychiatric wards showed that of all the pharmacologically and mechanically restrained patients (n=373) 34 (9.1%) had been frequently restrained (6 or more times). These patients accounted for 39.2% of all restraint episodes during the two-year study period. Adjusted binary logistic regression analyses showed that the odds for being frequently restrained were 91% lower among patients above 50 years compared to those aged 18–29 years; a threefold increase (OR=3.1) for those admitted 3 times or more compared to patients with only one stay; and, finally, a threefold increase (OR=3.1) if the length of stay was 16 days or more compared to those admitted for 0–4 days. Among frequently restrained patients, males (n=15) had significantly longer stays than women (n=19), and 8 of the females had a diagnosis of personality disorder, compared to none among males. Our study showed that being frequently restrained was associated with long inpatient stay, many admissions and young age. Teasing out patient characteristics associated with the risk of being frequently restraint may contribute to reduce use of restraint by developing alternative interventions for these patients.     

Connective tissue disease and other related rheumatic conditions among patients with finger and hand and temporomandibular joint prostheses in Denmark

OBJECTIVE: To determine if finger and hand joint prostheses or temporomandibular joint (TMJ) implants may be involved in the initiation of specific connective tissue diseases (CTD), a nationwide cohort in Denmark was followed prospectively to evaluate rates of CTD after receiving these implants. METHODS: Danish patients with finger and hand joint implants (n = 562) or TMJ implants (n = 351) were identified and followed for subsequent hospitalizations. Observed numbers of hospitalizations due to CTD were compared with expected numbers based on national CTD hospitalization rates. To avoid confounding by indication, patients with a hospital discharge diagnosis of a CTD prior to prosthetic surgery were excluded from the cohort. RESULTS: After 4142 person-years of followup in the finger and hand joint cohort, 9 hospitalizations due to CTD were found [standard hospitalization rate (SHR) = 1.5; 95% CI 0.7-2.9]. The TMJ cohort had 1500 person-years of followup and 2 hospitalizations due to CTD (SHR = 1.3; 95% CI 0.2-4.5). CONCLUSION: This is the first cohort study to examine the relations between these implants and CTD. Although the number of events was small, this systematic national study revealed no significant or large increase in risk of CTD after finger and hand joint implants or TMJ implants.     

Smoking Is a Risk Factor for Recurrence of Groin Hernia

Studies of connective tissue from patients with inguinal hernia have shown that smoking may be associated with hernia formation due to a defective connective tissue metabolism. Whether smoking is a risk factor for recurrence, too, was examined in this study. From December 1990 through December 1995, 649 patients underwent hernia repair as open sutured repair (Cooper ligament or abdominal ring repair) or as open mesh repair. Five hundred forty-four eligible patients were evaluated for recurrence 2 years postoperatively. Association between recurrence and 17 patient-, disease-, and intraoperative variables were analyzed by multiple logistic regression. The results showed that smoking was significantly and independently associated with recurrence compared to nonsmoking [odds ratio (OR = 2.22; 95% confidence interval (95% CI) = 1.19–4.15)]. Open sutured repair compared to open mesh repair was the most significant predictor for recurrence (OR = 7.23; 95% CI = 3.01–17.37). Surprisingly, local anesthesia was associated with a higher risk of recurrence compared to general anesthesia (OR = 2.44; 95% CI = 1.19–5.09). Potential confounders and other risk factors for hernia recurrence such as age, alcohol consumption, previous surgery, and anatomical characteristics of the hernia were adjusted for in the analysis. In conclusion, smoking is an important risk factor for recurrence of groin hernia, presumably due to an abnormal connective tissue metabolism in smokers.     

Application of the yeast two-hybrid system in molecular gerontology

Most – if not all – proteins are bound to interact with other proteins to exert their function, and thus the identification of the interaction partners of a protein is vital in proteomics. The yeast two-hybrid system is a popular and effective tool for studyingprotein–protein interactions. Although the advantages of the system are manifold, it also has certain drawbacks and limitations. The two-hybrid system has been shown to be extremely useful for placing a protein of unknown function within a functional context, thereby providing information about a putative role of the uncharacterised protein. This concept has also been successfully applied in molecular gerontology. This revised version was published online in July 2006 with corrections to the Cover Date.     

The vein of the vestibular aqueduct with potential pathologic perspectives.

HYPOTHESIS: Pathologic changes around the vein of the vestibular aqueduct (VVA) may cause obstruction to the flow of blood toward the sigmoid sinus. Furthermore, a distal obstruction of this vessel may be responsible for a development of a retrograde flow of blood with concomitant drainage of endolymphatic sac (ES) substances to the inner ear. BACKGROUND: The VVA is responsible for the venous drainage of the vestibular apparatus and endolymphatic duct and ES. Previous studies have linked the VVA to Ménière's disease. The aim of the present article was a 3-dimensional perspective study of the VVA with its adjacent anatomic structures. METHODS: In 14 rats, the VVA was examined by 3-dimensional reconstruction of 2-microm serial sections, corrosion cast technique, and scanning electron microscopy. RESULTS: From the external aperture of the vestibular aqueduct, the VVA is interposed between the ES and the operculum. Three to 4 collecting venules from the ES drain into the VVA. The VVA merges at an oblique angle with the sigmoid sinus. CONCLUSION: The VVA courses near the ES, operculum, and sigmoid sinus and is potentially vulnerable to expanding structures in the cranial posterior fossa. The possible role of the VVA for the function of the ES under normal and pathologic conditions is discussed.