Early Detection of Endolymphatic Hydrops using the Auditory Nerve Overlapped Waveform (ANOW).

Endolymphatic hydrops is associated with low-frequency sensorineural hearing loss, with a large body of research dedicated to examining its putative causal role in low-frequency hearing loss. Investigations have been thwarted by the fact that hearing loss is measured in intact ears, but gold standard assessments of endolymphatic hydrops are made postmortem only; and that no objective low-frequency hearing measure has existed. Yet the association of endolymphatic hydrops with low-frequency hearing loss is so strong that it has been established as one of the important defining features for Ménière's disease, rendering it critical to detect endolymphatic hydrops early, regardless of whether it serves a causal role or is the result of other disease mechanisms. We surgically induced endolymphatic hydrops in guinea pigs and employed our recently developed objective neural measure of low-frequency hearing, the Auditory Nerve Overlapped Waveform (ANOW). Hearing loss and endolymphatic hydrops were assessed at various time points after surgery. The ANOW detected low-frequency hearing loss as early as the first day after surgery, well before endolymphatic hydrops was found histologically. The ANOW detected low-frequency hearing loss with perfect sensitivity and specificity in all ears after endolymphatic hydrops developed, where there was a strong linear relationship between degree of endolymphatic hydrops and severity of low-frequency hearing loss. Further, histological data demonstrated that endolymphatic hydrops is seen first in the high-frequency cochlear base, though the ANOW demonstrated that dysfunction begins in the low-frequency apical cochlear half. The results lay the groundwork for future investigations of the causal role of endolymphatic hydrops in low-frequency hearing loss.

[Malnutrition, plasma proteins and immunoglobulins in Chilean puerperal women]. / Desnutrición, proteínas plasmáticas e inmunoglobulinas en puérperas chilenas.

Healthy lying-in women admitted to the Clinical Hospital of the University of Chile, most of them belonging to the low socioeconomic of Santiago (Chile), showed a steady decrease in the plasma levels of total protein, albumin, beta-globulin, IgA, and IgM, and also a striking increase in the plasma level of alpha 1-Globulin. This trend was ascertained from december 1982 to august 1985, and the pattern of plasma protein change is similar to that found in human malnutrition. The observed changes in the immunoglobulins levels suggest a different behavior between IgM and IgA that do not cross the placenta and IgG that crosses it.