Metastasis over implantable venous access ports.

Background: The totally implantable venous access port (TIVAP) is an important device for patients receiving chemotherapy. We have reported, to our knowledge, the first case of a metastatic tumor over a TIVAP implanted via the Seldinger technique with a subclavian vein puncture.

Methods: Our patient, a 48-year-old man with hard palate cancer, had metastasis over the TIVAP.

Assessment of gentamicin-induced vestibulotoxicity by click and galvanic vestibular-evoked myogenic potentials: a guinea pig investigation.

Objective: The aim of this investigation carried out with guinea pigs was to study the possible effects of a gentamicin treatment on the saccular macula and on its afferent vestibular ganglion neurons.

Methods: The gentamicin-induced impairment was analyzed using vestibular-evoked myogenic potentials (VEMPs) elicited by both click and galvanic vestibular stimulations (GVS). Fifty microl of saline or gentamicin solution (40 mg/ml) was dropped over the round window membrane of the right (control) and left (lesion) cochleae, respectively.

Physiological and morphological assessment of the saccule in Guinea pigs after noise exposure.

Objective: To investigate whether the saccule exhibits temporary or permanent functional loss resembling threshold shifts in auditory brainstem response (ABR) of guinea pigs following noise exposure.

Design: Randomly bred guinea pigs were divided into 3 groups: A (short-term noise exposure, 30 minutes, n = 15), B (long-term noise exposure, 40 hours, n = 9), and C (no noise exposure, n = 5).

Setting: University hospital.

Vestibular evoked myogenic potentials are heavily dependent on type I hair cell activity of the saccular macula in guinea pigs.

This study applied the vestibular evoked myogenic potential (VEMP) test to guinea pigs coupled with electronic microscopic examination to determine whether VEMPs are dependent on type I or II hair cell activity of the saccular macula. An amount of 0.05 ml of gentamicin (40 mg/ml) was injected directly overlaying, but not through, the round window membrane of the left ear in guinea pigs.

Correlating the cochleovestibular deficits with tumor size of acoustic neuroma.

Conclusion: The tumor size of acoustic neuroma correlates with cochleovestibular deficits. Those tumors with global frequency hearing loss, bilateral gaze nystagmus, or absent caloric and VEMP responses may indicate a tumor size >2.5 cm.

Over-expression of c-kit in a primary leiomyosarcoma of the thyroid gland.

Primary leiomyosarcoma of the thyroid gland is rare. In this paper, we report a case of high-grade leiomyosarcoma of the thyroid gland in a 43-year-old man. Lung metastasis was also noted in this patient.

Effect of intratympanic application of aminoglycosides on click-evoked myogenic potentials in Guinea pigs.

Objectives: Although numerous studies have identified damage to the cochlear and vestibular end organs as the primary site of aminoglycoside-induced ototoxicity, the effect on the saccule remains poorly understood, possibly due to lack of monitoring saccular function in experimental animals. Therefore, this study applied three kinds of aminoglycosides into the tympanic space of guinea pigs to examine their toxic impact on the saccule by way of click-evoked myogenic potential test coupled with morphologic assessment.

Design: Albino guinea pigs were treated with saline, gentamicin, tobramycin, or amikacin, with 10 animals assigned to each group.

A time course analysis of the changes in neuropeptide Y immunoreactivity in the rat cuneate nucleus following median nerve transection.

Using median nerve injury and immunocytochemical methods, we examined the temporal changes in neuropeptide Y (NPY) expression in the cuneate nucleus (CN) in rats following median nerve transection. Under normal circumstances, neuropeptide Y-immunoreactive (NPY-IR) fibers was not detectable in the CN. A few NPY-IR fibers were observed in the ipsilateral CN 5 days after the median nerve transection, and peaked at 4 weeks.

Changes in c-Fos protein expression in the rat cuneate nucleus after electric stimulation of the transected median nerve.

In this study we investigate temporal changes in Fos expression in cuneate neurons after a high-threshold electrical stimulation of the transected median nerve in rats. Two hours after injury of the median nerve when given electrical stimulation, c-Fos-immunoreactive (c-Fos-IR) cells were barely detected in the ipsilateral cuneate nucleus (CN). A few c-Fos-IR cells, however, were observed in the ipsilateral CN at 5 days.