|
Otorhinolaryngology News
Abreast Of Ear, Nose &
Throat / Head & Neck Advances
12 December, 2005
|
Hello, All. You are Welcome
to this week's ORL Update. I do hope you find my picks
for this week exciting and useful |
|
Biodun Olusesi,
Newsletter Editor |
Getting Nearer to the dreams of nanootology...?
When I presented the
first paper on nanootology
October 2002 to the Conference of Head & Neck
Surgeons in South Africa as a poster, most of the
conference participants view the new word more as
a curiosity than as something realizable in any
foreseeable future. Even the correspondence
I received from visitors and curious
researchers all over the world on the
contents of the website (http://www.nanootology.org)
were partly encouraging, largely cynical. The
first published step towards practical realization
of nanootology has just been taken by Tamura et al
(Laryngoscope.
2005 Nov;115(11):2000-2005)..
Abstract: OBJECTIVES:: This study aimed to
investigate the efficacy of encapsulating
therapeutic molecules in poly lactic/glycolic acid
(PLGA) nanoparticles for drug delivery to the
cochlea. STUDY DESIGN:: An experimental study.
METHODS:: We examined the distribution of
rhodamine, a fluorescent dye, in the cochlea,
liver, and kidney of guinea pigs. Intravenous
injection of rhodamine or rhodamine-encapsulated
PLGA nanoparticles was used to target the
fluorescent dye systemically to the liver, kidney,
and cochlea, and these molecules were applied
locally to the round window membrane (RWM) of the
cochlea. The localization of rhodamine
fluorescence in each region was quantitatively
analyzed. RESULTS:: After systemic application of
rhodamine nanoparticles, fluorescence was
identified in the liver, kidney, and cochlea. The
systemic application of nanoparticles had a
significant effect on targeted and sustained
delivery of rhodamine to the liver but not the
kidney or cochlea. Rhodamine nanoparticles placed
on the RWM were identified in the scala tympani as
nanoparticles, indicating that the PLGA
nanoparticles can permeate through the RWM.
Furthermore, the local application of rhodamine
nanoparticles to the RWM was more effective in
targeted delivery to the cochlea than systemic
application. CONCLUSIONS:: These findings indicate
that PLGA nanoparticles can be an useful drug
carrier to the cochlea via local application.
| |
|
TOP PICKS
 Isoflurane
and Noise from Otological Drills...
If your hospital is yet to acquire the fine otological
microdrill that generates little noise, but still has to
resort to use of bulky and noisy hand-held drills for
bone work in Middle ear and mastoid surgeries, then this
report by Kim et al from Kyoto University Japan (Laryngoscope.
2005 Nov;115(11):1996-1999), might be of interest to you,
regarding your fear of iatrogenic noise induced hearing
loss.
Abstract: HYPOTHESIS/OBJECTIVES:: To examine
the protective effect of general anesthesia with
isoflurane against noise-induced hearing loss in mice.
STUDY DESIGN:: Animal study using noise stimulation and
measurement of hearing in BALB/c mice. METHODS:: Mice
were exposed to 122 dB peak equivalent sound pressure
level click noise for 3 hours per day for 3 consecutive
days with or without anesthesia using isoflurane.
Hearing levels were measured and hair cell survival
ratio was observed. RESULTS:: In mice without
anesthesia, hearing threshold increased after noise
stimulation (73.7 dB hearing level [HL]) and persisted
for at least 1 month. However, in mice exposed to noise
under anesthesia, hearing loss was less severe (44.1 dB
HL) and had recovered more (26.5 dB HL) by one month.
Histological examination showed hair cell survival was
higher in anesthetized compared to non-anesthetized
mice. CONCLUSION:: These data indicate isoflurane
general anesthesia protects against noise-induced
hearing loss and tissue damage in mice.
Coming Events of Importance to Otolaryngologists in Africa...
- Annual West Africa College
of Surgeons Conference, Accra, Ghana, Feb 2006.
-
Otoacoustic emissions and or ABR in neonatal hearing
screening.....
A recent study from Taiwan (Linc HC et al, Laryngoscope
2005 Nov;115(11):1957-1962) compares the efficacy of
Transient Evoked Otoacoustic Emission (TEOAE) alone
with TEOAE plus ABR and concluded that the latter
decreases referral rates as well as lower intangible
costs and expenditures
 Abstract:
To compare the efficacy between one step with transient
evoked
otoacoustic emissions (TEOAE) and two steps with TEOAE
and automated
auditory brainstem response (AABR) in a newborn hearing
screening program.
We investigated their differences in referral rate, the
accurate identification rate of congenital hearing loss
(HL), and cost effectiveness. METHOD:: From November
1998 to December 2004, a total of 21,273 healthy
newborns were screened for HL in Mackay Memorial
Hospital, Taipei. In the periods from November 1998 to
January 2004 and from February 2004 to December 2004,
the screening tools used were TEOAE alone (n = 18,260)
and TEOAE plus AABR (n = 3,013), respectively. RESULTS::
A statistically significant decrease of referral rate
was achieved in the group using TEOAE and AABR as
screening tools when compared with TEOAE alone (1.8% vs.
5.8%). The accurate identification rate of congenital HL
was 0.45% in TEOAE protocol and 0.3% in TEOAE and AABR
protocol, which was not statistically significant. The
total direct costs per screening were 10.1 U.S. dollars
for the program using TEOAE alone and 8.9 U.S. dollars
for the TEOAE plus AABR program. The intangible cost,
however, was much higher in the earlier program because
of the higher referral rate.
CONCLUSION:: In terms of the efficacy of a hearing
screening program using
the one step TEOAE and two step TEOAE and AABR programs,
the later
significantly decreased the referral rate from 5.8% to
1.8%. No significant difference was noted between the
accurate identification rates of congenital HL. The
total costs, including expenditures and intangible cost,
were lower in the protocol with TEOAE plus AABR.
|
|
|
|
CLINICAL PHOTO OF THE WEEK |
 An
11-year old male presented with persistent
discharge of clear fluid from the point arrowed in
this picture during eating. The only significant
history was that of I&D of a 'boil' on the cheek
by a GP at age of 6 years. Examination showed an oblique
puckered scar above the angle of right mandible
(displayed on this picture). Radiological contrast
injected through the discharging focus ended blindly in a
pouch. Right parotid sialogram was abandoned
because of difficulty in visualizing right
Stenson's duct
|
| |
What is the diagnosis?
Parting Shot...
If you have an interesting
case to discuss or share with other Otolaryngologists
all over Africa, feel free to email
Me or at best go to
otolaryngology in Africa blogsite
and post your case
Also, if you are among those who requested for a copy
of DODA at the last ORLSON Meeting @ Port Harcourt,
please take time to view the
DODA - FAQ page,
and expect your copy of the program soon
Till Next Week,
Biodun |
|
|
This is a free email newsletter
circulating to Otolaryngologists in Africa, and interested
Otolaryngologists elsewhere. If you know anyone interested
in receiving this free newsletter, feel free to forward a
copy to such person or encourage them to email
orl-mailer@otolaryngologyinafrica.net for
subscription
© Copyright Dr 'Biodun
Olusesi,
2005 |
