PubMed Health⌕ Search

Biomedical subjects

L Michels

Publications and source records attributed to L Michels.

8 recordsLinked to original sources
PubMed2006

[The influence of the Tübingen soft palate plate and early cleft closure on swallowing and Eustachian tube function in children with Pierre Robin sequence].

CURRENT KNOWLEDGE: Children with Pierre Robin sequence (PRS) typically have difficulty with bolus transport and swallowing. Due to velopharyngeal insufficiency caused by the cleft palate, a high percentage of the children affected also have impaired Eustachian tube function. AIMS OF THE STUDY: In the literature, substantial information may be obtained on conductive hearing loss in PRS patients; however, no study has yet been performed to investigate whether wearing a soft palate plate and relatively early surgical cleft palate closure positively influence Eustachian tube function. In the present study this question was investigated. METHODS AND RESULTS: A total of 41 PRS children, 27 girls and 14 boys, were included in the study and were examined for hearing ability prior to and after surgical cleft palate closure. All of the children had been wearing a Tübingen soft palate plate until surgical cleft palate closure, which occurred at an age of 3-13 months (mean age 7.3 months). Based on data obtained prior to surgery by BERA, otoacoustic emissions and tympanometry, a hearing loss of more than 30 dB was diagnosed in 68.4% of the children. After 3-6 months, normal hearing ability was found in 70%. CONCLUSIONS: Wearing the Tübingen soft palate plate, and the improved swallowing function resulting from this, as well as early surgical cleft palate closure had a very positive impact on the hearing ability of the children included in the study.

Auditory Threshold↗
PubMed2005

[Factors influencing rehabilitation of sensorineural hearing loss with hearing aids].

BACKGROUND: A large proportion of older as well as younger patients do not use their hearing aids. Of the younger hearing impaired population, this occurs in the majority of those who do not benefit sufficiently from their hearing aids and, consequently, they face difficulties in their working and social life. SCIENTIFIC QUESTION: Our aim was to evaluate whether a classical hearing aid adjustment is of sufficient predictive value to determine whether adequate rehabilitation in everyday and professional life will occur. METHODS AND RESULTS: A questionnaire was returned by 197 adult hearing impaired patients. Only 108 were using their hearing aids all the time; 57 rarely and 32 never. The main reason for this low rehabilitation rate proved to be inadequate amplification. At the workplace, insufficient speech discrimination came into play. Another important factor was dysacusis induced by specific noise signals. There was an intolerable acoustic feedback in 40% which could not be sufficiently alleviated. Taking these results into account, only about a third of patients were sufficiently rehabilitated. CONCLUSIONS: Proof of effectiveness in a typical audiological testing situation is an important but not a fully reliable predictor for effectiveness in everyday life. Even when hearing aids are shown to be effective with such testing, their application in particular everyday or work situations may be insufficient of even impossible.

Equipment Failure Analysis↗
PubMed1998

African origin of human T-lymphotropic virus type 2 (HTLV-2) supported by a potential new HTLV-2d subtype in Congolese Bambuti Efe Pygmies.

We identified a potential new subtype within human T-cell lymphotropic virus type 2 (HTLV-2), HTLV-2d, present in members of an isolated Efe Bambuti Pygmy tribe. Two of 23 Efe Pygmies were HTLV-2 seropositive, with HTLV-2 Western blot and enzyme-linked immunosorbent assay reactivities. From one of them the entire genome of the HTLV-2 strain Efe2 could be amplified and sequenced. In all gene regions analyzed, this strain was the most divergent HTLV-2 strain, differing by 2.4% (tax/rex) to 10.7% (long terminal repeat) from both subtypes HTLV-2a and HTLV-2b, yet major functional elements are conserved. The similarity between the HTLV-2 Efe2 Gag and Env proteins and the corresponding HTLV-2a and -2b proteins is consistent with the observed serological reactivity. In the proximal pX region, one of the two alternative splice acceptor sites is abolished in HTLV-2 Efe2. Another interesting feature of this potential new subtype is that it has a Tax protein of 344 amino acids (aa), which is intermediate in length between the HTLV-2a Tax protein (331 aa) and the HTLV-2b and -2c Tax proteins (356 aa) and similar to the simian T-cell lymphotropic virus type 2 (STLV-2) PP1664 Tax protein. Together these two findings suggest a different phenotype for the HTLV-2 Efe2 strain. Phylogenetic analyses confirmed that the Pygmy Efe2 strain potentially belonged to a new and quite divergent subtype, HTLV-2d. When the STLV-2 bonobo viruses PP1664 and PanP were used as an outgroup, it was clear that the Pygmy HTLV-2 Efe2 strain had the longest independent evolution and that HTLV-2 evolution is consistent with an African origin.

Amino Acid Sequence↗
PubMed1985

Adriamycin-induced chronic proteinuria: a structural and functional study.

Focal, segmental glomerulosclerosis is frequently associated with chronic proteinuria and progressively declining renal function in humans as well as in experimental models of glomerular disease. Although little is known regarding the pathogenesis of this lesion, persistent, massive proteinuria has been associated with a poor prognosis. The administration of adriamycin to rats results in proteinuria of glomerular origin. We used this model to study the glomerular functional and structural alterations associated with proteinuria of 4 to 5 weeks duration. Studies of single nephron function revealed a 34% reduction in nephron plasma flow and a 50% decline in the glomerular ultrafiltration coefficient in rats given adriamycin. Single nephron glomerular filtration rate, however, was only modestly reduced (27%), because of an 8.0 mm Hg elevation of mean transcapillary hydraulic pressure difference (P less than 0.05). Morphologically, glomeruli of adriamycin-treated rats demonstrated significantly increased mesangial matrix and cellularity. In addition, glomerular capillaries frequently appeared enlarged, and epithelial cell bleb formation was evident. Focal glomerulosclerosis, however, was only rarely seen. The functional and morphologic characteristics of chronic adriamycin nephrosis are different from those associated with chronic proteinuria induced by repetitive administration of aminonucleoside of puromycin. Comparison of the two models suggests that the development of focal glomerulosclerosis can be dissociated from proteinuria and elevations of intraglomerular hydraulic pressures.

Animals↗