RESUMEN
Hereditary persistence of fetal hemoglobin (HPFH) is a benign condition in which significant fetal hemoglobin production continues well into adulthood, disregarding the normal shutoff point after which only adult-type hemoglobin should be produced. The percentage of incorrect expression might be as low as 10%-15% or as high as 100% of the total hemoglobin, usually higher in homozygotes than in heterozygotes. The present case is a typical example of homozygous HPFH.
RESUMEN
18p deletion syndrome is characterized by the deletion of short arm of chromosome 18. Presentation of this syndrome is quite variable with dysmorphic features, growth deficiencies, and mental retardation with poor verbal performance. Few patients even fail to thrive when malformations involving the heart and brain are severe. In the present article, we report an isolated case of 18p deletion in a 23-year-old female who for the first time reported to the hospital for dental problems. The patient was short statured with mental retardation and craniofacial, skeletal, dental, and endocrinal abnormalities. Such presentation warrants prompt diagnosis for effective management. Furthermore, genetic counseling for such patients and their families should be considered as a part of treatment itself.
RESUMEN
Osteochondroma is the most common benign neoplasm of the skeleton commonly affecting the long bones due to endochondral growth. In the craniofacial region this tumour is very rare. The sites of predilection are the coronoid process and the mandibular condyle. Here, we report an exceptional case of osteochondroma originating from the maxillary posterior region in a 26-year-old male patient, mimicking an odontome, not reported earlier in the literature. We also discuss the importance of various imaging modalities, most importantly, computed tomography (CT) in the evaluation of such lesions. However, histopathology remains the mainstay for definitive diagnosis in such conditions.
RESUMEN
In earlier studies, the volatile anesthetics and the endogenous cannabinoid anandamide have been shown to inhibit the function of alpha(7)-nicotinic acetylcholine receptors. In the present study, interactions between the effects of volatile anesthetics and anandamide on the function of alpha(7)-nicotinic acetylcholine receptors expressed in Xenopus oocytes were investigated using the two-electrode voltage-clamp technique. Anandamide and volatile anesthetics isoflurane and halothane inhibited currents evoked with acetylcholine (100 microM) in a reversible and concentration-dependent manner. Coapplication of anandamide and volatile anesthetics caused a significantly greater inhibition of alpha(7)-nicotinic acetylcholine receptor function than anandamide or volatile anesthetics alone. Analyses of oocytes by matrix-assisted laser desorption/ionization mass spectroscopy indicated that volatile anesthetics did not alter the lipid profile of oocytes. Results of studies with chimeric alpha(7)-nicotinic acetylcholine-5-HT(3) receptors comprised of the N-terminal domain of the alpha(7)-nicotinic acetylcholine receptor and the transmembrane and carboxyl-terminal domains of 5-HT(3) receptors suggest that while isoflurane inhibition of the alpha(7)-nicotinic acetylcholine receptor is likely to involve the N-terminal region of the receptor, the site of action for anandamide involves transmembrane and carboxyl-terminal domains of the receptors. These data indicate that endocannabinoids and isoflurane have additive inhibitory effects on alpha(7)-nicotinic acetylcholine receptor function through allosteric binding sites located on the distinct regions of the receptor.
Asunto(s)
Anestésicos por Inhalación/farmacología , Ácidos Araquidónicos/farmacología , Moduladores de Receptores de Cannabinoides/farmacología , Antagonistas Nicotínicos/farmacología , Oocitos/efectos de los fármacos , Alcamidas Poliinsaturadas/farmacología , Receptores Nicotínicos/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Endocannabinoides , Femenino , Halotano/farmacología , Técnicas In Vitro , Isoflurano/farmacología , Oocitos/fisiología , Receptores Nicotínicos/fisiología , Xenopus laevis , Receptor Nicotínico de Acetilcolina alfa 7RESUMEN
The effects of the antipsychotic clozapine on the function of the cloned alpha(7) subunit of the nicotinic acetylcholine (nACh) receptor expressed in Xenopus oocytes was investigated by using the two-electrode voltage-clamp technique. Clozapine reversibly inhibited nicotine (10 microM)-induced currents in a concentration-dependent manner (300 nM to 90 microM), with an IC(50) value of 3.2+/-0.4 microM. The effect of clozapine was not dependent on the membrane potential. Clozapine did not affect the activity of endogenous Ca(2+)-dependent Cl(-) channels since the inhibition by clozapine was unaltered by the intracellularly injected Ca(2+) chelator BAPTA and perfusion with Ca(2+)-free bathing solution containing 2mM Ba(2+). Clozapine decreased the maximal nicotine-induced responses without significantly affecting its potency, indicating that it acts as a noncompetitive antagonist on alpha(7)-nACh receptors. In hippocampal slices, the whole-cell recordings from CA1 pyramidal neurons indicated that the increases in the frequency and amplitudes of the GABA-mediated spontaneous inhibitory postsynaptic currents induced by bath application of 2 mM choline, a specific agonist for alpha(7)-nACh receptors, were abolished after 10 min application of 5 microM clozapine. In conclusion, these results demonstrate that clozapine inhibits the function of alpha(7)-nACh receptors expressed in Xenopus oocytes and in hippocampal neurons.