Clinical and molecular characterization of Chilean patients with X-linked hypophosphatemia.

We report the most comprehensive clinical and molecular characterization of XLH patients performed in Chile. We show high prevalence of musculoskeletal burden and pain, associated with significantly impaired physical capacity and quality of life, with many relevant complications presenting more frequently than previously reported in cohorts from developed countries. INTRODUCTION: Our current understanding of the clinical presentation and natural history of X-linked hypophosphatemia (XLH) comes mainly from cohorts from developed countries, with limited data on the clinical and genetic abnormalities of XLH patients in South America. OBJECTIVE: To describe the clinical, biochemical, and molecular presentation of patients with XLH in Chile. METHODS: Patients with XLH referred by endocrinologist throughout Chile were included. Demographic data and clinical presentation were obtained from a clinical interview. Surveys were applied for quality of life (QoL), pain, and functionality. FGF23 was measured by ELISA, and genetic testing was performed. Imaging studies were conducted to assess skeletal and renal involvement. RESULTS: We included 26 patients, aged 2-64 years, from 17 unrelated Chilean families. All pediatric patients but only 40% of adults were receiving conventional therapy, while 65% of all patients had elevated alkaline phosphatase. All patients had mutations in PHEX, including 5 novel variants. Radiographic skeletal events (RSE) and enthesopathies in adults were frequent (34% and 85%, respectively). The duration of treatment was associated with fewer RSE (p < 0.05). Most adults reported pain and impaired QoL, and 50% had impaired physical capacity. The number of enthesopathies was associated with worse pain and stiffness scores (p < 0.05). CONCLUSION: Chilean patients with XLH have a high prevalence of musculoskeletal burden associated with pain and impaired physical capacity and QoL, especially in adults who were generally undertreated. These data identify a significant unmet need, inform our understanding of the current status of patients, and can guide care for XLH patients in similarly socioeconomically defined countries.

An unusual case of adenoid cystic carcinoma with hard palate perforation.

Adenoid cystic carcinoma is a malignant tumor which occurs frequently in hard palate associated with minor salivary glands. The lesion generally presents as a painful slow growing mass and it is characterized by recurrences and distant metastasis resulting in a poor prognosis for the patient. This paper reports an atypical adenoid cystic carcinoma with palatal perforation which occurred in a young woman. Initial diagnostic hypothesis were necrotizing sialometaplasia and lues. Although adenoid cystic carcinoma is common in hard palate, cases with palatal perforation are uncommon and may lead to delay in diagnosis and therapy.

Identification and stability of a new bichalcone in Achyrocline satureioides spray dried powder.

A new chemical structure, the 4,2',4",2'''-tetrahydroxy-6',6'''-dimethoxy-4'-O-4'''- bichalcone, named achyrobichalcone was isolated and identified from an Achyrocline satureioides spray-dried powder (SDP80). The thermal and photo stability of this new compound as well as that of the main polyphenols present in the spray dried powder, quercetin, luteolin, 3-O-metylquercetin and the corresponding kinetics of degradation are reported. In the long-term testing (30 +/- 2 degrees C/75 +/- 5% RH, 12 months), the total polyphenols contained in SDP80 demonstrated to be stable, remaining higher than 90% after a 12 month exposure. The photo stability testing revealed that all polyphenols were stable for 48 h when SDP80 was conditioned in amber or transparent flasks and exposed to UV-C radiation (light express LE UV, 254 nm, 30W). In contrast, when unprotected, the polyphenols demonstrated to be sensitive to both, thermal stress testing (80 +/- 2 degrees C), for 14 days and to UV-C radiation. Luteolin showed to be the most stable against UVC light and 3-O-methylquercetin against temperature. The achyrobichalcone demonstrated to be the more unstable against both, temperature and light. The kinetics of polyphenol thermal degradation (80 +/- 2 degrees C, 49 days) and photodegradation (UV-C radiation, 96 h) followed, 2nd and 1st order reaction, respectively.

Neurotensin modulates central muscarinic receptors, an effect which does not involve the high-affinity neurotensin receptor (NTS1).

Neurotensin (NT) is a tridecapeptide distributed in central and peripheral nervous systems, which can behave as a neurotransmitter or neuromodulator at central and peripheral levels. Herein we tested the potential effect of this peptide on quinuclidinyl benzilate ([3H]-QNB) binding to muscarinic receptor in rat CNS membranes. It was observed that NT decreased up to 50-70% ligand binding at 1x10(-7) M-1x10(-5) M concentration in cerebral cortex, cerebellum and striatum. In the hippocampus, NT exerted a biphasic effect, behaving as a stimulator in the presence of 1x10(-12) M-1x10(-10) M concentration but as an inhibitor at 1x10(-8) M-1x10(-5) M concentration. In order to test the involvement of high-affinity NT receptor (NTS1) in NT inhibitory effect, assays were carried out in the presence of 1x10(-6) M NT and/or SR 48692 (Sanofi-Aventis, U.S., Inc.), a specific antagonist for this receptor, dissolved in dimethylsulfoxide (DMSO) 10% v/v. As controls, membranes incubated with DMSO and/or NT 1x10(-6) M plus DMSO were processed. It was found that NT+DMSO decreased [3H]-QNB binding to cerebral cortex, cerebellum and hippocampal membranes by 49%, 32% and 53%, respectively. This inhibition was not observed with the DMSO control group. Membrane preincubation with 1x10(-6) M SR 48692 failed to alter NT effect on binding. SR 48692 at 1x10(-6) M concentration decreased the binding by 50% only in cerebral cortex membranes, suggesting a possible direct effect of the antagonist on muscarinic receptors in this area. It was therefore concluded that the high-affinity NT receptor may not be involved in ligand binding inhibition to muscarinic receptor by NT.

Creatine protects against the convulsive behavior and lactate production elicited by the intrastriatal injection of methylmalonate.

Methylmalonic acidemias are metabolic disorders caused by a severe deficiency of methylmalonyl-CoA mutase activity, which are characterized by neurological dysfunction, including convulsions. It has been reported that the accumulating metabolite, L-methylmalonic acid (MMA), inhibits succinate dehydrogenase leading to ATP depletion in vitro, and that the intrastriatal injection of MMA induces convulsions through secondary NMDA receptor stimulation. In this study we investigated the effect of creatine (1.2, 3.6 and 12.0 mg/kg, (i.p.), [DOSAGE ERROR CORRECTED] succinate (1.5 micromol/striatum) and MK-801 (3 nmol/striatum) on the convulsions and on the striatal lactate increase induced by MMA (4.5 micromol/striatum) in rats. The effect of creatine on the striatal phosphocreatine content and on MMA-induced phosphocreatine depletion was also evaluated. Creatine, succinate and MK-801 pretreatment decreased the number and duration of convulsive episodes and the lactate increase elicited by MMA. Creatine, but not succinate, prevented the convulsions and the lactate increase induced by the direct stimulation of NMDA receptors. Acute creatine administration increased the total striatal phosphocreatine content and prevented MMA-induced phosphocreatine depletion. Our results suggest that MMA increases lactate production through secondary NMDA receptor activation, and it is proposed that the anticonvulsant effect of creatine against MMA-induced convulsions may be due to an increase in the phosphocreatine content available for metabolic purposes.

What factors influence the age at diagnosis of hemophilia? Results of the French hemophilia cohort.

OBJECTIVE: The diagnosis of hemophilia was reported as delayed in historic studies. We therefore investigated this issue to provide current epidemiologic data in a large series of patients. STUDY DESIGN: The French cohort provided the opportunity to investigate the age at diagnosis and the circumstances of diagnosis in 599 individuals with hemophilia born between 1980 and 1994. The type and the severity of hemophilia, the family history, and the period of birth were analyzed as potential modifying factors. RESULTS: The median age at diagnosis was 7.7 months, with significant differences among subgroups: 5.8 months in severe hemophilia, 9.0 months in moderate forms, 28.6 months in mild forms, 0.4 months in the case of hemophilic brothers, and 10.1 months in de novo hemophilia, which accounted for 55.3% of cases. In severe forms we observed a trend for earlier diagnosis throughout 3 consecutive periods from 1980 to 1994. Of bleeding episode, testing due to family history, or routine testing, bleeding was the main circumstance of diagnosis (59.9%). CONCLUSIONS: Diagnosis was made earlier than in historic series, but it remained somewhat delayed. Early diagnosis will require efforts in the fields of genetic counseling and specific diagnosis of early bleeding, even without family history, because of the high incidence of de novo hemophilia.

Thy-1 binds to integrin beta(3) on astrocytes and triggers formation of focal contact sites.

BACKGROUND: Thy-1 is an abundant neuronal glycoprotein in mammals. Despite such prevalence, Thy-1 function remains largely obscure in the absence of a defined ligand. Astrocytes, ubiquitous cells of the brain, express a putative Thy-1 ligand that prevents neurite outgrowth. In this paper, a ligand molecule for Thy-1 was identified, and the consequences of Thy-1 binding for astrocyte function were investigated. RESULTS: Thy-1 has been implicated in cell adhesion and, indeed, all known Thy-1 sequences were found to contain an integrin binding, RGD-like sequence. Thy-1 interaction with beta3 integrin on astrocytes was demonstrated in an adhesion assay using a thymoma line (EL-4) expressing high levels of Thy-1. EL-4 cells bound to astrocytes five times more readily than EL-4(-f), control cells lacking Thy-1. Binding was blocked by either anti-Thy-1 or anti-beta3 antibodies, by RGD-related peptides, or by soluble Thy-1-Fc chimeras. However, neither RGE/RLE peptides nor Thy-1(RLE)-Fc fusion protein inhibited the interaction. Immobilized Thy-1-Fc, but not Thy-1(RLE)-Fc fusion protein supported the attachment and spreading of astrocytes in a Mn(2+)-dependent manner. Binding to Thy-1-Fc was inhibited by RGD peptides. Moreover, vitronectin, fibrinogen, denatured collagen (dcollagen), and a kistrin-derived peptide, but not fibronectin, also mediated Mn(2+)-dependent adhesion, suggesting the involvement of beta3 integrin. The addition of Thy-1 to matrix-bound astrocytes induced recruitment of paxillin, vinculin, and focal adhesion kinase (FAK) to focal contacts and increased tyrosine phosphorylation of proteins such as p130(Cas) and FAK. Furthermore, astrocyte binding to immobilized Thy-1-Fc alone was sufficient to promote focal adhesion formation and phosphorylation on tyrosine. CONCLUSIONS: Thy-1 binds to beta3 integrin and triggers tyrosine phosphorylation of focal adhesion proteins in astrocytes, thereby promoting focal adhesion formation, cell attachment, and spreading.

Ligand binding to CNS muscarinic receptor is transiently modified by convulsant 3-mercaptopropionic acid administration.

The administration of convulsant drugs has proven a powerful tool to study experimental epilepsy. We have already reported that the administration of convulsant 3-mercaptopropionic acid (mp) at 150 mg/kg enhances binding affinity of muscarinic antagonist [3H]quinuclidinyl benzilate ([3H]QNB) to certain rat CNS membranes during seizure and postseizure without affecting site number. Results obtained with a 100-mg/kg dose of mp have shown reversible increases in [3H]QNB binding to cerebellum and hippocampus, whereas a delayed response has been found in striatum. Neither a subconvulsant dose nor in vitro addition modifies binding. In order to evaluate preseizure, seizure as well as early (30 min) and late (24 h) postseizure stages, we employed a 50 mg/kg dose and tested [3H]QNB binding to CNS membranes. Changes in binding were as follows (in %): in cerebellum, +37, +86, and +40 at preseizure, seizure and early postseizure stages, respectively, but there was a decrease at late postseizure; in hippocampus, +27 at pre- and seizure stages, but a decrease at early and late postseizure. No changes were found in striatum or cerebral cortex membranes at any stage studied. Saturation curves analysed by Scatchard plots indicated that changes in [3H]QNB binding to cerebellar membranes are attributable to an increase in ligand affinity at seizure, followed by a decrease in binding site number at postseizure. A similar profile was observed for hippocampus except that the decrease in binding site number, though lower than at postseizure, was already evident at seizure stage. Results confirm a region-specific response to the convulsant and transient changes provide an example of neuronal plasticity.

Calcitonin modifies ligand binding to muscarinic receptor in CNS membranes.

Calcitonin (CT) is a peptide produced by the thyroid gland, whose best described role is to prevent bone reabsorption, though it also participates in other biological functions through both central and peripheral mechanisms. CT is able to inhibit brain Na(+), K(+)-ATPase activity (Rodríguez de Lores Arnaiz, López Ordieres, Peptides 1997;18:613-5) and a relationship between such enzyme activity and cholinergic function has been suggested. Accordingly, we tested CT effect on [(3)H]-quinuclidinyl benzilate ([(3)H]-QNB) binding to rat CNS membranes to determine whether the peptide is able to modify the cholinergic muscarinic receptor as well. It was found that 1x10(-7)-1x10(-5) M CT decreased 20-70% ligand binding to hippocampal, cerebellar, cortical and striatal membranes. Scatchard analysis of saturation curves showed that 5x10(-6) M CT significantly modified binding kinetic constants, thus it increased roughly 220% K(d) values and decreased 20-36% B(max) values in cerebral cortical and cerebellar membranes. Since the peptide decreases affinity ligand binding and reduces the number of binding sites, CT may well be acting as a cholinergic modulator through a decrease in muscarinic receptor functionality.

Brain soluble fractions which modulate Na+, K+-ATPase activity likewise modify muscarinic receptor.

Two brain soluble fractions, named peaks I and II, which respectively stimulate and inhibit neuronal Na+, K+-ATPase activity, have been isolated by gel filtration in Sephadex G-50. Since cholinergic transmission seems related to such enzyme activity, in this study we evaluated the effect of brain peak I, peak II, a more purified fraction II-E and commercial ouabain, on specific binding of the muscarinic antagonist [3H]quinuclidinyl benzilate to membranes from rat cerebellum, hippocampus and cerebral cortex. We found that binding was increased by peak I and decreased by peak II, II-E and ouabain, all effects proving concentration-dependent. Since the changes exerted on the muscarinic receptor followed a pattern similar to the one already described for synaptosomal membrane Na+, K+-ATPase activity, both systems seem to interact at a functional level.

Major histocompatibility complex (MHC) class III genetics in two Amerindian tribes from southern Brazil: the Kaingang and the Guarani.

Population genetic studies of the major histocompatibility complex (MHC) class III region, comprising C2, BF and C4 phenotypes, and molecular genetic data are rarely available for populations other than Caucasoids. We have investigated three Amerindian populations from Southern Brazil: 131 Kaingang from Ivaí (KIV), 111 Kaingang (KRC) and 100 Guarani (GRC) from Rio das Cobras. Extended MHC haplotypes were derived after standard C2, BF, C4 phenotyping and restriction fragment length polymorphism (RFLP) analysis with TaqI, together with HLA data published previously by segregation analysis. C2 and BF frequencies corresponded to other Amerindian populations. C4B*Q0 frequency was high in the GRC (0.429) but low in the Kaingang. Unusual C4 alleles were found, viz. C4A*58, A*55 and C4B*22 (presumably non-Amerindian) and aberrant C4A*3 of Amerindian origin occurring with a frequency of 0.223 in the GRC. C4A*3 bands of homo- and heterozygous individuals carrying this variant were Rodgers 1 positive and Chido 1,3 positive, showed a C4A specific lysis type and a C4A like alpha-chain. Polymerase chain reaction studies and sequencing showed that this is based on a C4A*3 duplication with a regular C4A*3 and a partially converted C4A*0304 carrying the C4B specific epitopes Ch 6 and Ch 1,3. Associations of class III haplotypes with particular RFLP patterns were similar to those reported for Caucasoids. The previously described association between combined C4A and CYP21P deletions and the 6.4 kb TaqI fragment was not seen in these Amerindians. This fragment occurred within a regular two locus gene structure in the Kaingang, representing a "short" gene at C4 locus I. C4 and CYP21 duplications were frequently observed. The distribution of extended MHC haplotypes provides evidence for a close relationship between the KIV and KRC and a larger genetic distance between the two Kaingang groups and the GRC.

[Extent of endemic Chlamydia trachomatis in the metropolitan area of Buenos Aires (Argentina)]. / Dimensión de la endemia por Chlamydia trachomatis en el área de la ciudad de Buenos Aires (Argentina).

BACKGROUND: In this report we inform laboratory results accumulated over ten years (1986-1995). The number of cases, and the geographic distribution, allow us to present a very reliable data about the dimension of Chlamydia trachomatis urogenital infections in Buenos Aires city and we also compare this profile with the prevalence of Neisseria gonorrhoeae in the same area and period of time. METHODS: Patients were females and males (aged from 15 to 49 years old) attending clinics not specialize in Sexually Transmitted Diseases (STD). Intent to isolation of C. trachomatis was done in McCoy cells culture. Patients for Neisseria gonorrhoeae investigation were a population assisted at the Clinic for STD of an University Hospital (aged from 15 to 75 years old). Study for detection of N. gonorrhoeae was developed by direct and conventional culture technics. RESULTS: 4128 endocervical samples from women with lower genital tract pathology were studied and C. trachomatis infection was detected in 25.6 +/- 4.8%. Over 1206 male urethral samples 29.5 +/- 4.47% shows positive cultures. Except for years 1989 and 1990 in which annual percentage of infected women showed slightly higher percentage over the global average, the results shows a very stable annual values, as it was also found in male patients. Infection in males shows a discrete tendency to be higher compare with values obtained in women. Global results of the evolution of prevalence of N. gonorrhoeae infection shows a very different pattern. Since 1992 we demonstrate a very significant decrease in the number of confirmed cases. CONCLUSIONS: We concluded that patients not attending a STD clinic, reveal a high and very stable endemic level of C. trachomatis lower tract urogenital infections. N. gonorrhoeae in this population is a very sporadic or null finding. Prevalence of Chlamydial infection in STD centers is even higher and also shows an stable profile. In people attending STD clinics N. gonorrhoeae shows a very different kinetics, with an important decrease in prevalence in the last five years.

Area-dependent CNS membrane response of muscarinic receptor to convulsant 3-mercaptopropionic acid.

It has already been shown that the administration of convulsant 3-mercaptopropionic acid at 150 mg/kg enhances binding affinity of muscarinic antagonist [3H]quinuclidinyl benzilate ([3H]QNB) to certain rat CNS membranes without affecting site number. Herein we employed a 100 mg/kg dose and tested [3H]QNB binding to cerebellar, hippocampal, and striatal membranes obtained from rats killed at preseizure, seizure, and postseizure stages. In cerebellum, binding increased 24, 65, and 19% a1 preseizure, seizure, and postseizure stages, respectively; in hippocampus, values were 12 and 20% higher at pre- and seizure stages, but failed to differ from controls at postseizure; in striatum, increases of 10 and 18% were recorded at seizure and postseizure, with no changes at preseizure. Neither a subconvulsant dose (20 mg/kg) nor in vitro drug addition had any effect on binding. Results indicate a differential response to the convulsant, with reversible changes in cerebellum and hippocampus, and a delayed response in striatum, supporting the concept of area-dependent neuronal plasticity.

The developmental regulation and biosynthesis of GPI-related structures in Leishmania parasites.

Most macromolecules on the surface of Leishmania parasites, including the major surface proteins and a complex lipophosphoglycan (LPG) are anchored to the plasma membrane via GPI glycolipids. Free glycoinositol-phospholipids (GIPLs) which are not linked to protein or phosphoglycan are also abundant in the plasma membrane. From structural and metabolic labeling studies it is proposed that most Leishmania species express three distinct pathways of GPI biosynthesis. Some of these pathways (i.e. those involved in the protein and LPG anchor biosynthesis) are down-regulated during the differentiation of the insect (promastigote) stage to the mammalian (amastigote) stage. In contrast, the GIPLs are expressed in high copy number in both developmental stages. Based on analysis of the lipid moieties of the different GPI species it is possible that the pathways of GPI anchor and GIPL biosynthesis are located in different subcellular compartments. The relative flux through the GIPL and LPG biosynthetic pathways has been examined in L. major promastigotes. These studies showed that while the rate of synthesis of the GIPLs and LPG is similar, LPG is shed more rapidly from the plasma membrane and has a higher turnover. The possible metabolic relationship between the GIPL and LPG biosynthetic pathways is discussed.

The developmental regulation and biosynthesis of GPI-related structures in Leishmania parasites

Most macromolecules on the surface of Leishmania parasites, including the major surface proteins and a complex lipophosphoglycan (LPG) are anchored to the plasma membrane via GPI glycolipids. Free glycoinositol-phospholipids (GIPLs) which are not linked to protein or phosphoglycan are also abundant in the plasma membrane. From structural and metabolic labeling studies it is proposed that most Leishmania species express three distinct pathways of GPI biosynthesis. Some of these pathways (i.e those involved in the protein and LPG anchor biosynthesis) are down-regulated during the differentiation of the insect (promastigote) stage to the mammalian (amastigote) stage. In contrast, the GIPLs are expressed in high copy number in both developmental stages. Based on analysis of the lipid moieties of the different GPI species it is possible that the pathways of GPI anchor and GIPL biosynthesis are located in different subcellular compartments. The relative flux through the GIPL and LPG biosynthetic pathways has been examined in L. Major promastigotes. These studies showed that while the rate of synthesis of the GIPLs and LPG is similar, LPG is shed more rapidly from the plasma membrane and has a higher turnover. The possible metabolic relationship between the GIPL and LPG biosynthetic pathways is discussed

Area-specific modification of acetylcholinesterase activity following 3-mercaptopropionic acid-induced seizures.

Acetylcholinesterase activity (AChE) was assayed in rat CNS membrane fractions after administration of the convulsant 3-mercaptopropionic acid (150 mg/kg, ip). In comparison with saline-injected controls, total AChE activity decreased 12-20% in striatum and cerebellum during seizure and postseizure but failed to change in cerebral cortex. Specific AChE activity, assayed in the presence of 10(-4) M ethopropazine (a butyrylcholinesterase inhibitor), decreased 15-25% in striatum and cerebellum, increased 20-45% in hippocampus, but remained unchanged in cerebral cortex. Saline injection alone increased AChE activity in striatum (68%) and cerebellum (36%) but failed to modify enzyme activity in hippocampus and cerebral cortex. To conclude, AChE sensitivity to convulsant and saline administration is tissue-specific and not restricted to cholinergic areas.

The glycoinositol phospholipids of Leishmania mexicana promastigotes. Evidence for the presence of three distinct pathways of glycolipid biosynthesis.

Most macromolecules at the cell surface of parasitic protozoa of the genus Leishmania, including the major surface glycoproteins and a complex lipophosphoglycan (LPG), are attached to the plasma membrane via glycosyl-phosphatidylinositol (GPI) anchors. Free glycoinositol phospholipids (GIPLs) which are not linked to protein or phosphoglycan have also been found. In this study, we show that L. mexicana promastigotes synthesize two distinct GIPL lineages, comprising at least 10 glycolipid species. These structures were characterized using a combination of gas-liquid chromatography-mass spectrometry, methylation linkage analysis, and chemical and exoglycosidase sequencing. The major lineage contains GIPLs with the glycan structures Man alpha 1-3Man alpha 1-4GlcN (iM2), Man alpha 1-6(Man alpha 1-3)Man alpha 1-4GlcN (iM3), and Man alpha 1-2Man alpha 1-6(Man alpha 1-3)Man alpha 1-4GlcN (iM4), which are linked to alkylacyl-PI containing predominantly C16:0 and C18:0 fatty acids and C18:0 alkyl chains (referred to as the hybrid type GIPLs). A proportion of the iM3 and iM4 species (32 and 4%, respectively) are substituted with an ethanolamine-phosphate residue. The location of this residue on the core glucosamine residue was inferred from the results of methylation analyses and alpha-mannosidase digestion. The minor GIPL lineage contains GIPLs with the same glycan sequences as the glycolipid anchor of LPG (referred to as the type-2 GIPLs). The alkylacyl-PI or lyso-alkyl-PI lipid moieties of these GIPLs differ from those of the hybrid type GIPLs and from the main pool of alkylacyl-PI in containing significant levels of C24:0 and C26:0 alkyl chains. The most polar of these GIPLs, LPGp, has the properties expected of a biosynthetic precursor to the LPG, having the structure, [formula: see text] Finally, the GPI anchors of the major promastigote proteins were found to contain the glycan sequence Man alpha 1-2Man alpha 1-6Man alpha 1-4GlcN, and an alkylacyl-PI lipid moiety which was highly enriched for C24:0 or C26:0 alkyl chains. These data suggest that L. mexicana promastigotes contain three distinct pathways of GPI biosynthesis. The possibility that the distinct alkyl chain compositions of the different GPI glycolipids reflects the subcellular compartmentalization of different GPI biosynthetic pathways is discussed.

3-mercaptopropionic acid administration increases the affinity of [3H]quinuclidinyl benzilate binding to membranes of the striatum and cerebellum.

It is known that quinuclidinyl benzilate (QNB) binds specifically and with high affinity to the cholinergic muscarinic receptor and that behaves as a potent antagonist of this receptor. We have analysed L-[3H]QNB binding to rat CNS membranes after the administration of the convulsant 3-mercaptopropionic acid (MP) (150 mg.kg-1, i.p.). The studies were done in rats killed at two stages: during and after seizures. No changes in [3H]QNB binding to hippocampus and cerebral cortex membranes were found. [3H]QNB binding increased about 40 and 80% in striatum and cerebellum membranes, respectively. The changes were observed both in seizure and postseizures states. The study was extended to the assay of [3H]QNB binding kinetic constants in the anatomical areas modified by the convulsant. The analysis of the saturation curves indicated an increase in the binding affinity but no change in the number of binding sites. Hill number values were near the unit suggesting a non-cooperative interaction between the ligand and the receptor, and the labelling of a homogeneous population of receptor sites. The results suggest the participation of some cholinergic pathways in the development and maintenance of MP-induced seizures.

Escleroterapia endoscópica de varices esof gicas sangrantes: resultados obtenidos en 31 casos tratados y su evolución durante 28-33 meses post-escleroterapia / Follow up the 31 cases after endoscopic sclerotherapy of the bleeding esophagic varicose veins

Entre 1986 a 1989 hemos esclerosado v rices sangrantes en 31 pacientes adultos (18 casos asistenciales y 13 casos privados); 28 (90/100) presentaban hepatopatía alcohólica crónica, 2 (6.3/100) cirrosis criptogénica y 1 (3.2/100)trombosis portal ideop tica. Quince pacientes fueron admitidos con sangrado agudo; a 7 se les esclerosó sangrando activamente (etapa aguda) y a los 8 restantes después de estabilizarlos hemodin micamente y controlada la hemorragia con la colocación de sonda de balones (etapa temprana). Los otros 16 pacientes fueron esclerosados electivamente semanas a meses después de haber presentado su último sangrado. No hubo ningún caso de mortalidad directamente relacionada con el procedimiento; la frecuencia y severidad de las complicaciones asociadas al procedimiento fueron moderadas y semejantes a lo reportado por otros autores en la literatura. En el grupo agudo se logró controlar la hemorragia después de la primera sesión de escleroterapia; sin embargo 4 de estos pacientes fallecieron entre uno y seis días después de la escleroterapia debido a insuficiencia hep tica irreversible sin que volvieran a sangrar...

Monomeric serum calcitonin and bone turnover during anticonvulsant treatment and in congenital hypothyroidism.

Decreased basal and calcium-stimulated calcitonin serum levels have been found in children with congenital hypothyroidism and in those receiving anticonvulsant drugs. The purpose of our investigation was to confirm these results using a new technique for calcitonin measurement and to study the effect on bone turnover. Calcitonin serum levels were measured with two different antibodies before and after a low-dose Ca infusion in patients receiving phenytoin, primidone, carbamazepine, or valproate and in patients with congenital hypothyroidism receiving L-thyroxine. In comparison with control values, basal and Ca-stimulated extractable calcitonin, representing the monomeric and biologically active form of the hormone, were moderately decreased in patients with epilepsy receiving phenytoin and primidone, and severely decreased in patients with hypothyroidism. Ca and bone metabolism were normal, except for an elevated renal threshold for phosphate (indicating phosphate conservation) in patients receiving phenytoin and primidone, and increased fasting urinary excretion of Ca and hydroxyproline (indicating increased bone resorption) in patients with hypothyroidism. The secretory capacity of the C cells for monomeric calcitonin is decreased in children receiving treatment with some, but not all, anticonvulsant drugs, and lacking in patients with hypothyroidism. Patients with calcitonin deficiency may be prone to osteopenia if the tendency to increased osteoclastic activity is aggravated by secondary hyperparathyroidism in patients with epilepsy receiving phenytoin and primidone or by inappropriate thyroid replacement therapy in patients with hypothyroidism.