MCT8 is Downregulated by Short Time Iodine Overload in the Thyroid Gland of Rats.

Wolff-Chaikoff effect is characterized by the blockade of thyroid hormone synthesis and secretion due to iodine overload. However, the regulation of monocarboxylate transporter 8 during Wolff-Chaikoff effect and its possible role in the rapid reduction of T4 secretion by the thyroid gland remains unclear. Patients with monocarboxylate transporter 8 gene loss-of-function mutations and monocarboxylate transporter 8 knockout mice were shown to have decreased serum T4 levels, indicating that monocarboxylate transporter 8 could be involved in the secretion of thyroid hormones from the thyroid gland. Herein, we aimed to evaluate the regulation of monocarboxylate transporter 8 during the Wolff-Chaikoff effect and the escape from iodine overload, besides the importance of iodine organification for this regulation. Monocarboxylate transporter 8 mRNA and protein levels significantly decreased after 1 day of NaI administration to rats, together with decreased serum T4; while no alteration was observed in LAT2 expression. Moreover, both monocarboxylate transporter 8 expression and serum T4 was restored after 6 days of NaI. The inhibition of thyroperoxidase activity by methimazole prevented the inhibitory effect of NaI on thyroid monocarboxylate transporter 8 expression, suggesting that an active thyroperoxidase is necessary for MCT8 downregulation by iodine overload, similarly to other thyroid markers, such as sodium iodide symporter. Therefore, we conclude that thyroid monocarboxylate transporter 8 expression is downregulated during iodine overload and that the normalization of its expression parallels the escape phenomenon. These data suggest a possible role for monocarboxylate transporter 8 in the changes of thyroid hormones secretion during the Wolff-Chaikoff effect and escape.

Nematode infections of the eye: toxocariasis and diffuse unilateral subacute neuroretinitis.

In many parts of the world, parasitic infections of the eye are a major cause of blindness. The parasites Toxocara canis, Onchocerca volvulus, Taenia solium, Ancylostoma caninum, and Cysticercus celulosae all have been responsible for blinding ocular infections. The nematodes T. canis and Toxocara cati are parasitic roundworms that infect dogs (toxocarosis), other canidae, and cats. Ocular toxocariasis is an uncommon worldwide infection caused by the nematode larvae of T. canis, commonly found in dogs. Human transmission is usually via geophagia, the ingestion of food contaminated with Toxocara eggs, or contact with infected puppies, often resulting in devastating ocular or systemic effects. Ocular toxocariasis is typically a monocular disease of young children, and its clinical findings include posterior and peripheral retinochoroiditis, optic papillitis, and endophthalmitis. The inflammatory response created by ocular involvement may result in epiretinal membrane formation, traction retinal detachment, and combined traction-rhegmatogenous retinal detachment. Diffuse unilateral subacute neuroretinitis is another ocular parasitic infection that usually results in severe visual loss. Evidence suggests that diffuse unilateral subacute neuroretinitis is caused by a solitary unidentified nematode of two different sizes, but to date, only a small number of nematodes have been recovered from eyes affected with the infection. Diffuse unilateral subacute neuroretinitis occasionally can affect the fellow eye.

Visual field defects in children with congenital glaucoma.

PURPOSE: To determine visual field defects in a cohort of children with congenital glaucoma. METHODS: Monocular visual fields were measured in 24 meridians for targets V4e, I4e, I2e, and I1e, using a Goldmann perimeter in a group of 13 children between the ages of 4 and 14 years with congenital glaucoma and 10 age-matched healthy children. Localized visual field defects (eg, paracentral scotoma, nasal step, and arcuate scotoma) were determined by abnormal findings or shape of the eye in at least one of each of the targets presented. RESULTS: Visual field extent for target 12e was significantly constricted for unilateral and bilateral cases of congenital glaucoma when compared with control eyes. A post-hoc procedure (Tukey Test) showed significant differences between unilateral cases and normal control eyes, and between bilateral cases (best outcome eye) and normal control eyes. Stimuli V4e and 14e results were comparable for patients and normals. Stimulus I1e showed significantly different total extent visual field for bilateral and normal controls. Specific visual field defects were found only in bilateral cases. Paracentral scotoma was found in 1 of 12 eyes with bilateral congenital glaucoma. Nasal steps were found in 6 of 12 eyes with bilateral congenital glaucoma. Arcuate scotoma were found in 4 of 12 eyes with bilateral congenital glaucoma. CONCLUSION: Localized visual fields were found in 37.5% of eyes with congenital glaucoma. Early treatment for congenital glaucoma provided better visual field outcome.

Diffuse bilateral subacute neuroretinitis: first patient with documented nematodes in both eyes.

OBJECTIVE: To describe the first patient with documented evidence of diffuse unilateral subacute neuroretinitis (DUSN) in both eyes. METHODS: A 10-year-old healthy Brazilian girl was first seen with signs of late-stage DUSN in both eyes. A careful search for a nematode was performed in each eye. RESULTS: A motile 550- to 660-microm nematode was found in the inferotemporal retina of the left eye. A similar-sized motile nematode was found in the superotemporal retina of the right eye. Both nematodes were treated with argon green laser applications with bilateral improvement of visual function. CONCLUSION: Although most patients with DUSN do not develop the disease in the fellow eye, this case demonstrates that DUSN can occasionally affect both eyes.

[Lesion of the Lissauer tract and of the posterior horn of the gray substance of the spinal cord and the electrical stimulation of the central nervous system for the treatment of brachial plexus avulsion pain]. / A lesão do trato de Lissauer e do corno posterior da substância cinzenta da medula espinal e a estimulação elétrica do sistema nervoso central para o tratamento da dor por avulsão de raízes do plexo braquial.

We analyze the effectiveness of the treatment of 10 patients of brachial plexus avulsion pain. Seven underwent dorsal root entry zone lesions (DREZ), 3, dorsal column stimulation (DCS) and, 2 thalamic stimulation (TS). DCS resulted in immediate improvement of pain in 50% of the patients. After a long term follow up period, just 25% of the patients were still better. TS resulted the in temporary improvement of 2 patients. Both had full recurrence few months after the operation. Immediate improvement of the symptoms occurred in all patients treated by DREZ. After a long term follow up period, excellent results were observed in 71.4% of the patients and good results in the remainder. The complication rate was higher among DREZ patients. It is concluded that DREZ is a better procedure for treatment of brachial plexus avulsion pain than DCS and TS (p = 0.0046); however, DCS and TS are safer.

[Partial ventriculectomy in a child--the Batista technique]. / Ventriculectomia parcial em criança--técnica de Batista.

We present the case of a two and a half year old child with idiopatic dilated cardiomyopathy and end-stage congestive heart failure (NYHA III-IV) who underwent "partial ventriculectomy". The operation was performed under normothermic cardiopulmorary bypass and normothermic oxygenated blood cardioplegia and consisted of removal of a large wedge of muscle from the lateral wall of the left ventricle beginning at the apex and extending between the papillary muscles, ending proximal to the mitral annulus. Pre-operative the left ventricular ejection fraction (EF) was 13% by echocardiography and 20% by radionuclide ventriculography. Postoperative avaliation showed improvement of EF to 50% and 30%, respectively. The child was in functional class I (NYHA) on discharge from hospital (16th postoperative day).

[Management of febrile infants younger than 2 months of age at the Emergency Care Unit: diagnosis aspects and therapeutics]. / Febre no lactente jovem atendido em Serviço de Emergência: aspectos diagnósticos e terapêuticos.

82 febrile young infants were studied, prospectively, at the Emergency Service in Hospital Universitário-University of São Paulo. All the children were kept at the Emergency ward for 24 hours. Clinical and laboratory investigations were performed and when necessary, administration of antibiotic agents were started. 18 infants exhibited potentially severe bacterial infections (21.9%). Several important disorders were recognized in 40 infants (48.8%). All infants were followed until the end of the febrile episode: 20 children as inpatients and 62 as outpatients. 38 infants received antibiotic therapy (46.3%). Evolution was satisfactory in all patients. The authors detected in young febrile infants potentially dangerous clinical conditions that need close observation, laboratorial investigation and frequently antimicrobial therapy. The observation period at the Emergency ward was important to allow these procedures and to decide about hospitalization need.

Diffuse unilateral subacute neuroretinitis. Report of transvitreal surgical removal of a subretinal nematode.

BACKGROUND: The precise identification of nematodes which cause diffuse unilateral subacute neuroretinitis (DUSN) has been unsuccessful. Shape and size are useful in the initial stages of identification, but histopathologic examination usually is necessary for accurate classification. Intact nematodes recovered from patients with DUSN have been mentioned scarcely in the literature. The authors report the first case of DUSN in which a viable nematode was removed successfully via a transvitreal surgical approach and recovered for parasitologic study. METHODS: Bimanual pars plana vitrectomy was performed in a 9-year-old Brazilian boy with typical DUSN in its late stage. During surgery, a motile subretinal nematode was confirmed temporal to the macular area. A retinotomy was created adjacent to the nematode. The subretinal material then was aspirated with a 20-gauge soft-tip needle, and parasitologic examination was performed. RESULTS: Based on length (630 m x 10(-6)) and width (30 m x 10(-6)) of the nematode and other features such as a small buccal capsule, an esophagus one third of body length, and tapered tail, a morphologic identification of the nematode was made as a third-stage Toxocara larva. Histopathologic examination could not be performed for confirmation because of subsequent deterioration of the specimen. CONCLUSIONS: Although direct laser photocoagulation of the nematode is the treatment of choice for DUSN, surgical transvitreal removal of the nematode may be indicated in selected cases. This method for treatment allows removal of the nematode for parasitologic identification.

Early postoperative appearance of radiofrequency lesions on magnetic resonance imaging.

Eleven patients who underwent stereotactic radiofrequency lesions in the central nervous system had magnetic resonance imaging follow-up within 72 hours of surgery to determine the early appearance of their lesions. Eight patients with severe tremor, one with chronic pain, and two with dystonia were analyzed. There were six female patients and five male patients, age 7 to 75 years (mean +/- standard deviation = 42 +/- 21). Magnetic resonance imaging was performed postoperatively at 32 +/- 25 hours (range, 3-72). Postoperative T1-weighted spin echo images demonstrated foci of iso- to hyperintensity surrounded by an edge of hypointensity, and corresponding T2-weighted images showed a lesion with three concentric zones consisting of inner hypointense, middle hyperintense, and outer hypointense zones. Gadolinium increased T1-weighted image lesion visibility, and a ring of enhancement around the zone of hypointensity was observed. Lesions could be seen as early as 3 hours after surgery. The lesions were best shown on gadolinium-enhanced T1-weighted images and on T2-weighted images. The edema surrounding the lesion increased over time, up to the 72 hours studied. These data provide important information on the development of lesion appearance, which may be applied in the development of real-time magnetic resonance imaging monitoring of radiofrequency lesion formation. This technique associated with electrophysiological response and the real-time visualization of the anatomic correlation of the probe may allow for a very precise and selected lesion in the central nervous system for the treatment of functional disorders and brain tumors.

Diffuse unilateral subacute neuroretinitis in South America.

We describe two cases of diffuse unilateral subacute neuroretinitis in South America. These Brazilian patients presented with subretinal worms similar in size to those described in the southeastern United States. This is the first report, to our knowledge, of diffuse unilateral subacute neuroretinitis occurring outside the United States and Caribbean Islands.

Unusual central chorioretinitis as the first manifestation of early secondary syphilis.

Three young, otherwise healthy patients had a similar picture of unilateral central chorioretinitis associated with severe visual loss. Fluorescein angiography disclosed diffuse leakage under the neurosensory retina in the posterior pole, associated with multifocal areas of staining along the retinal vessels. Systemic examination showed a positive fluorescent treponemal antibody absorption test and a sharp increase in VDRL titers, indicative of active secondary syphilis. The patients responded dramatically to penicillin treatment, with visual recovery and resolution of the fundus lesions.

Pilomatrixoma. An unusual case with secondary corneal ulcer.

A 51-year-old man presented with a three-month history of a red and painful right eye. A corneal ulcer was diagnosed, and laboratory workup failed to disclose an etiologic factor. A white tumor, with an irregular and calcified surface, found in the superior tarsal conjunctiva, was considered to be the cause of the corneal ulcer. The tumor proved to be a pilomatrixoma that presumably developed from a congenitally ectopic hair follicle.