Neurofibromatosis segmentaria: Comunicación de dos casos / Segmental Neurofibromatosis: A report of two cases

Resumen La neurofibromatosis (NF) segmentaria, actualmente llamada NF mosaico, es una variante rara de neurofibromatosis, sin afectación sistémica y limitada a un segmento corporal. Los pacientes no presentan historia familiar de enfermedad. El cuadro clínico se caracteriza por manchas café con leche, neurofibromas o ambos. Se comunican dos casos de niñas con NF segmentaria solo con cambios pigmentarios,sin alteraciones sistémicas.

Abstract True segmental neurofibromatosis is an uncommon variant of neurofibromatosis, without systemic involvementand limited to a body segment. Patients don´t have family history of disease. The manifestations arecharacterized by café au lait spots, neurofibromas or both. We report two cases of girls with segmental NF with pigmentary changesonly, without systemic alterations.

Phosphodiesterase-5 is a therapeutic target for peripheral neuropathy in diabetic mice.

Peripheral neuropathy is a common and major complication of diabetes, the underlying mechanisms of which are not fully understood. Using a mouse model of type II diabetes, the present study investigated the role of phosphodiesterase-5 (PDE5) in peripheral neuropathy. BKS.Cg-m+/+Leprdb/J (db/db) mice were treated with sildenafil, a specific inhibitor of PDE5, at doses of 2 and 10 mg/kg or saline. Levels of PDE5 and morphometric parameters in sciatic nerve tissue as well as the motor and sensory function were measured in these mice. In diabetic mice, PDE5 expression in sciatic nerve tissue was significantly upregulated, whereas the myelin sheath thickness, myelin basic protein (MBP), and subcutaneous nerve fibers were significantly reduced. Treatment with sildenafil significantly improved neurological function, assayed by motor and sensory conducting velocities and thermal and mechanical noxious stimuli, concomitantly with increases in myelin sheath thickness, MBP levels, and subcutaneous nerve fibers. In vitro, hyperglycemia upregulated PDE5 in Schwann cells and reduced Schwann cell proliferation, migration, and expression of brain-derived neurotrophic factor (BDNF). Blockage of PDE5 with sildenafil increased cyclic guanosine monophosphate (cGMP) and completely abolished the effect of hyperglycemia on Schwann cells. Sildenafil upregulated cGMP-dependent protein kinase G I (PKGI), whereas inhibition of PKGI with a PKG inhibitor, KT5823, suppressed the inhibitory effect of sildenafil on Schwann cells. These data indicate that hyperglycemia substantially upregulates PDE5 expression and that the cGMP/PKG signaling pathway activated by sildenafil mediates the beneficial effects of sildenafil on diabetic peripheral neuropathy.

[Intervention for improving the coproparasitological diagnosis in the Province of Las Tunas, Cuba, 1993-1994]. / Intervención para mejorar el diagnóstico coproparasitológico en la Provincia "Las Tunas", Cuba, 1993-1994.

Control of quality of coproparasitological diagnosis was carried out in the Province "Las Tunas", between January and March 1993, It was found that 72% of coproparasitological microscopists had deficiencies related to the diagnosis, due to several causes: The microscopists did not receive any periodical training, as they did not participate at the parasitological section; the microscopists had no manual of reference; they had less than ten years of experience; they did not know the concentration technics that were established in the country. Between July 1993 and January 1994 two Medical Parasitology Courses were imparted. In July 1994 another quality control was performed. 80% of evaluated microscopists obtained good results. Through this study was established the National Parasitology Quality System Control that supports the National Intestinal Parasites Control Program.

[Hepatitis B prevention and risk of HIV infection in children injured by discarded needles and/or syringes]. / Prevención de hepatitis B y riesgo de infección por VIH en niños accidentados con agujas y/o jeringuillas abandonadas.

OBJECTIVES: Main aim: to study the application of mixed prophylaxis against Hepatitis B viral infection (HB) in children injured by discarded needles and/or syringes. Secondary aim: to find in the group under study the incidence of HIV infection caused by these accidents. DESCRIPTION: Descriptive study. SETTING: 12 de octubre University Hospital, Madrid. PATIENTS: Children injured by discarded needles and/or syringes and referred to the Preventive Medicine Service between May 1988 and April 1995 (7 years). INTERVENTIONS: 1) Serological study for HB and HIV; 2) application to unprotected children of HB mixed prophylaxis (specific Immunoglobulin--IGHB--plus vaccination) and 3) Post-vaccination serological check-ups for HB and HIV at 6 and 12 months from the incident. MEASUREMENTS AND MAIN RESULTS: 249 children, whose average age was 5.8 +/- 3.37, were seen (158 boys, 63.5% and 91 girls, 36.5%). 189 (75.9% of the total) received a dose of IGHB and 171 (71.8%) completed the HB vaccinations. Post-vaccination serological check-ups covered 144 children (84.2%). 101 children (40.6%) completed the HIV check-ups. No HIV infection was detected. CONCLUSIONS: 1) HB mixed prophylaxis in children without serological protection is adequate for dealing with these incidents. 2) The risk of HIV infection should not be discounted, but is probably very slight. 3) The procedure should be put into practice in PC, with some shortening of HIV follow-up periods, as a measure to improve compliance.

Silica subsurface amine effect on the chemical stability and chromatographic properties of end-capped immobilized artificial membrane surfaces.

The silica surface of immobilized artificial membranes containing phosphatidylcholine (IAM.PC) has approximately two aminopropyl groups per immobilized phosphatidylcholine molecule. Primary amines near the silica subsurface adsorb biomolecules and also decrease the chemical stability of IAM.PC surfaces. Consequently, subsurface amines were end-capped by several methods including silylating reagents, acetyl analogues, glycidol, methyl glycolate, short-chain anhydrides (3-6 carbons/anhydride chain), and long-chain anhydrides (10-12 carbons/anhydride chain). All end-capping reactions resulted in loss of the initially immobilized phosphatidylcholine molecule. However, the amount of PC loss during end capping was very low (for alkyl anhydride end-capping reactions) to very high (for silylation end-capping reactions). After end capping, IAM.PC showed increased chemical stability compared to non end-capped IAM.PC surfaces. The chemical stability of IAM packing material was monitored by phospholipid leaching from IAM surfaces exposed to organic and aqueous solvents using thin-layer chromatography, 1H NMR spectroscopy, infrared spectroscopy, and mass spectrometry. IAM.PC packing material end capped with long-chain anhydrides exhibited the greatest chemical stability, i.e., little or no detectable phospholipid leaching when challenged with aqueous and/or organic solvents. The chromatography of acidic and basic compounds on end-capped and non-end-capped IAM.PC surfaces was studied. Compared to non-end-capped IAM.PC HPLC columns, the chromatographic retention times of acidic compounds (deoxynucleotides) decreased after end capping. In contrast, the retention times of basic compounds (amphetamine analogues) increased on end-capped IAM.PC HPLC columns relative to non-end-capped IAM.PC HPLC columns. This indicates that these solutes have access to the silica subsurface amines during chromatography.

Preliminary evaluation of manassantin A, a potential neuroleptic agent from Saururus cernuus.

Manassantin A (MNS-A), a novel dineolignan isolated from Saururus cernuus was evaluated for its central depressant effects. Intraperitoneal (IP) administration of MNS-A to mice at nontoxic doses caused a decrease in spontaneous motor activity and inhibition of amphetamine-induced stereotypy, with an ED50 of 0.21 +/- 0.02 mg/kg for its antiamphetamine activity. Doses of MNS-A up to the LD50 did not produce catalepsy and ptosis as were observed with haloperidol used as a reference drug. The compound caused a dose-dependent hypothermia, while haloperidol was not very effective in this test. Potentiation of pentobarbital-sleeping time was observed to be of comparable degree with both drugs. In spite of the higher toxicity (acute LD50 5.4 +/- 0.2 mg/kg, IP) than that shown by haloperidol, the somewhat selective neuroleptic profile of MNS-A makes it an interesting candidate for more detailed studies.

Antibiotic principle of Eupatorium capillifolium.

Ethanolic extracts of Eupatorium capillifolium (Lam) Small showed activity against Bacillus subtilis grown in a chemically defined medium but not in a complex natural medium. The active principle was isolated as a colorless crystalline solid. A study of its properties and mass spectral fragmentation pattern showed that it was costic acid, a sesquiterpenic acid previously isolated from Costus root oil. The observed inactivity of costic acid against B. subtilis in a complex medium was shown to be due to the presence in the medium of glutamic acid, which is capable of reversing 90% of the activity of costic acid.

[Cortical diffusion characteristics of seizures induced in the form of Ammoni: I. Mechanical stimulation]. / Características de la difusión cortical de los paroxismos originados en asta de Ammón: I.-Estimulación mecánica

We have studied the cortical diffusion characteristics of seizures induced at cornu Ammonis with mechanical stimulation. We have observed that cerebral cortex syncronizes with cornu Ammonis showing a similar morphology. The cortical diffusion is iniciated at the homolateral occipital area. The focal paroxismal activity of one of the cornu Ammonis can be spread to the contralateral homologous area, being then cornu Ammonis the responsible structure for the bilateral cortical diffusion. Nonetheless it has been observed that being the paroxismal activity localized at one of the cornu Ammonis formation the cortical activity is spread to both hemispheres. We must consider in this case that the bilateral cortical diffusion is originated in an intermediate structure between cornu Ammonis and cerebral cortex. Very often the corical paroxismal diffusion is simultaneous with recruiting phases. (hese and some other considerations induce as to think that the cyngulus might be an important structure for the bilateral cortical diffusion of focal paroxismal activity localized an one of the cornu Ammonis.