Oculocutaneous albinism resulting from genetic defect of melanin synthesizing system is characterized by pale skin, straw-colored hair, hypopigmentation of the iris, hypoplasia of fovea, photophobia, low visual acuity and strabismus. In general, oculocutaneous albinism can be distinguished by its clinical feature and hair follicle incubation test but should be diagnosed by electron microscopic findings of the skin which is exposed to sunlight. We experienced a case of 6-year-old female oculocutaneous albinism that showed clinical typical features and was diagnosed through electron microscopic finding of many immature melanosomes of the skin in the back of the hand. We report this unusual case with literature review.
Albinism, Oculocutaneous* ; Child ; Female ; Hair ; Hair Follicle ; Hand ; Humans ; Hypopigmentation ; Iris ; Melanins ; Melanosomes ; Photophobia ; Skin ; Strabismus ; Sunlight ; Visual Acuity

The facial nerve is mainly composed of motor fibers and is distributed to the muscles of facial expressions. In ophthalmology clinics, orbicularis oculi muscle innervated by the facial nerve is involved in spontaneous and voluntary blinking, winking, and more forceful eyelid closure. To understand pathophysiogy of facial nerve palsy due to brain stem lesion involving nucleus, 50% Horseradish Peroxidase (HRP) was injected into nerve stump innervating orbicularis oculi muscle of cat and serial sections of midbrain were studied with light and dark field of light microscope to examine morphology and distribution of the facial nuclei. The HRP-labelled motor neurons were located exclusively within the intermediate division of the ipsilateral facial nuclei and no labelled neurons were found in the contralateral facial nuclei, in the nuclei of the trigeminal nerve, or any other brain stem nuclei. The mean diameter of HRP-labelled motor neurons was 45 micrometer. Most of them were multipolar in shape containing many dendrites. These result suggest that the intermediate division of ipsilateral facial nuclei play an important role in innervating orbicularis oculi muscle.
Animals ; Armoracia* ; Blinking ; Brain Stem ; Cats* ; Dendrites ; Eyelids ; Facial Expression ; Facial Nerve ; Horseradish Peroxidase* ; Mesencephalon ; Motor Neurons* ; Muscles ; Neurons ; Ophthalmology ; Paralysis ; Trigeminal Nerve

The spontaneous contractions of gastric smooth muscles are regulated by slow waves, which are modulated by both nervous system and humoral agents. This study was designed to examine the effects of Prostaglandin E2 (PGE2) on the contractile and electrical activities of antral smooth muscles in guinea-pig stomach, using an intracellular recording technique. To elucidate the underlying mechanism for its effect on contractility, ionic currents were also measured using a whole-cell patch clamp method. The basal tone by PGE2 was variable, whereas the magnitude of phasic contractions was reduced (19.0 +/- 2.1%, n=19). The resting membrane potentials were hyperpolarized (-4.4+/-0.5 mV, n=10), and plateau potentials were lowered (-2.9+/-0.5 mV, n=10). In most cases, however, the initial peak potentials of slow waves were depolarized more by PGE2 than those of control. The frequency of the slows wave was increased from 5.7+/-0.2 cycles/min to 6.5+/-0.2 (n-22). Voltage-operated Ca2+ currents were decreased by PGE2 (n=5). Voltage-operated K+ currents, both Ca-dependent and Ca-independent, were increased (n-5). These results suggest that PGE2 plays an important role in the modulation of gastric smooth muscle activities, and its inhibitory effects on the contractility and activities of slow waves are resulted from both decrease of Ca2+ currents and increase of K+ currents.
Dinoprostone* ; Membrane Potentials ; Muscle, Smooth ; Nervous System ; Stomach*

Many reports suggest that neurotensin (NT) in the gastrointestinal tract may play a possible role as a neurotransmitter, a circulating hormone, or a modulator of motor activity. NT exerts various actions in the intestine; it produces contractile and relaxant responses in intestinal smooth muscle. This study was designed to investigate the effect of NT on motility of antral circular muscle strips in guinea-pig stomach. To assess the role of Ca2+ influx in underlying mechanism, slow waves were simultaneously recorded with spontaneous contractions using conventional intracellular mircoelectrode technique. At the concentration of 10-7 M, where NT showed maximum response, NT enhanced the magnitude (863 +/- 198%, mean +/- SEM, n = 13) and the frequency (154 +/- 10.3%, n = 11) of spontaneous contractions. NT evoked a slight hyperpolarization of membrane potential, tall and steep slow waves with abortive spikes (278 +/- 50%, n = 4). These effects were not affected by atropine (2 micrometer), guanethidine (2 micrometer) and tetrodotoxin (0.2 micrometer). NT-induced contractile responses were abolished in Ca2+-free solution and reduced greatly to near abolition by 10 micrometer of verapamil or 0.2 mM of CdCl2. Verapamil attenuated the effects of NT on frequency and amplitude of the slow waves. Taken together, these results indicate that NT enhances contractility in guinea-pig gastric antral circular muscle and Ca2+ influx through the voltage-operated Ca2+ channel appears to play an important role in the NT-induced contractile mechanism.
Atropine ; Cadmium Chloride ; Gastrointestinal Tract ; Guanethidine ; Intestines ; Membrane Potentials ; Motor Activity ; Muscle, Smooth ; Neurotensin* ; Neurotransmitter Agents ; Stomach ; Tetrodotoxin ; Verapamil

OBJECTICE: To compare the use of conventional, real-time compound, and pulse-inversion harmonic imaging in the evaluation of breast nodules. MATERIALS AND METHODS: Fifty-two breast nodules were included in this study, conducted between May and December 2000, in which conventional, real-time compound, and pulse-inversion harmonic images were obtained in the same plane. Three radiologists, each blinded to the interpretations of the other two, evaluated the findings, characterizing the lesions and ranking the three techniques from grade 1, the worst, to grade 3, the best. Lesion conspicuity was assessed, and lesions were also characterized in terms of their margin, clarity of internal echotexture, and clarity of posterior echo pattern. The three techniques were compared using Friedman's test, and interobserver agreement in image interpretation was assessed by means of the intraclass correlation coefficient. RESULTS: With regard to lesion conspicuity, margin, and internal echotexture of the nodules, real-time compound imaging was the best technique (p < 0.05); in terms of posterior echo pattern, the best was pulse-inversion harmonic imaging (p < 0.05). Real-time compound and pulse inversion harmonic imaging were better than conventional sonography in all evaluative aspects. Interobserver agreement was greater than moderate. CONCLUSION: Real-time compound and pulse-inversion harmonic imaging procedures are superior to conventional sonography in terms of both lesion conspicuity and the further characterization of breast nodules. Real-time compound imaging is the best technique for evaluation of the margin and internal echotexture of nodules, while pulse-inversion harmonic imaging is very effective for the evaluation of the posterior echo patterns.
Breast Neoplasms/*ultrasonography ; Comparative Study ; Female ; Fibrocystic Disease of Breast/*ultrasonography ; Human ; Middle Age ; Ultrasonography, Mammary/*methods