The actin binding sites of talin have both distinct and complementary roles in cell-ECM adhesion

Cell adhesion requires linkage of transmembrane receptors to the cytoskeleton through intermediary linker proteins. Integrin-based adhesion to the extracellular matrix (ECM) involves large adhesion complexes that contain multiple cytoskeletal adapters that connect to the actin cytoskeleton. Many of these adapters, including the essential cytoskeletal linker Talin, have been shown to contain multiple actin-binding sites (ABSs) within a single protein. To investigate the possible role of having such a variety of ways of linking integrins to the cytoskeleton, we generated mutations in multiple actin binding sites in Drosophila talin. Using this approach, we have been able to show that different actin-binding sites in talin have both unique and complementary roles in integrin-mediated adhesion. Specifically, mutations in either the C-terminal ABS3 or the centrally located ABS2 result in lethality showing that they have unique and non-redundant function in some contexts. On the other hand, flies simultaneously expressing both the ABS2 and ABS3 mutants exhibit a milder phenotype than either mutant by itself, suggesting overlap in function in other contexts. Detailed phenotypic analysis of ABS mutants elucidated the unique roles of the talin ABSs during embryonic development as well as provided support for the hypothesis that talin acts as a dimer in in vivo contexts. Overall, our work highlights how the ability of adhesion complexes to link to the cytoskeleton in multiple ways provides redundancy, and consequently robustness, but also allows a capacity for functional specialization.

Talin variant P229S compromises integrin activation and associates with multifaceted clinical symptoms

Adhesion of cells to the extracellular matrix (ECM) must be exquisitely coordinated to enable development and tissue homeostasis. Cell-ECM interactions are regulated by multiple signalling pathways that coordinate the activation state of the integrin family of ECM receptors. The protein talin is pivotal in this process, and talin's simultaneous interactions with the cytoplasmic tails of the integrins and the plasma membrane are essential to enable robust, dynamic control of integrin activation and cell-ECM adhesion. Here, we report the identification of a de novo heterozygous c.685C>T (p.Pro229Ser) variant in the TLN1 gene from a patient with a complex phenotype. The mutation is located in the talin head region at the interface between the F2 and F3 domains. The characterization of this novel p.P229S talin variant reveals the disruption of adhesion dynamics that result from disturbance of the F2-F3 domain interface in the talin head. Using biophysical, computational and cell biological techniques, we find that the variant perturbs the synergy between the integrin-binding F3 and the membrane-binding F2 domains, compromising integrin activation, adhesion and cell migration. Whilst this remains a variant of uncertain significance, it is probable that the dysregulation of adhesion dynamics we observe in cells contributes to the multifaceted clinical symptoms of the patient and may provide insight into the multitude of cellular processes dependent on talin-mediated adhesion dynamics.

Zn2+ triggered two-step mechanism of CLIC1 membrane insertion and activation into chloride channels

The chloride intracellular channel (CLIC) protein family displays the unique feature of altering its structure from a soluble form to a membrane-bound chloride channel. CLIC1, a member of this family, is found in the cytoplasm or in internal and plasma membranes, with membrane relocalisation linked to endothelial disfunction, tumour proliferation and metastasis. The molecular switch promoting CLIC1 activation remains under investigation. Here, cellular Cl⁻ efflux assays and immunofluorescence microscopy studies have identified intracellular Zn²⁺ release as the trigger for CLIC1 activation and membrane insertion. Biophysical assays confirmed specific binding to Zn²⁺, inducing membrane association and enhancing Cl⁻ efflux in a pH-dependent manner. Together, our results identify a two-step mechanism with Zn²⁺ binding as the molecular switch promoting CLIC1 membrane insertion, followed by pH-mediated activation of Cl⁻ efflux.

Summary: Identification of a two-step mechanism of CLIC1 membrane insertion based on Zn²⁺ binding and pH activation of Cl⁻ efflux.

Uveitis intermedia as the initial presentation of a primary lymphoma of the central nervous system

Primary central nervous system lymphoma is one of the most infrequent brain tumours, accounting for 3% of primary central nervous system neoplasms. In addition to its low prevalence, clinical presentation is usually nonspecific, leading to diagnostic delay. Intraocular involvement occurs in 15% of cases, and disease onset in this location is even rarer. We present a case of a patient with intermediate uveitis as the first clinical manifestation of this neoplasm.

Clinical characteristics, management, and one-year risk of complications among patients with heart failure with and without type 2 diabetes in Spain

OBJECTIVE

This work aims to describe the clinical characteristics and therapeutic management and to determine cardiovascular outcomes after one year of follow-up in a contemporaneous population with heart failure (HF) with and without type 2 diabetes in Spain. These factors were also analyzed in the DAPA-HF-like population (patients who met most inclusion criteria of the DAPA-HF trial) and in patients treated with SGLT2 inhibitors at baseline.

METHODS

This work is an observational, retrospective, population-based study using the BIG-PAC database. The index date was January 1, 2019. People aged ≥ 18 years who received care for HF in 2019 were selected. Events that occurred in 2019 were analyzed.

RESULTS

We identified 21,851 patients with HF (age 78.0 ± 11.3 years, 53.0% men, 50.9% with HF with reduced left ventricular ejection fraction, 44.5% in NYHA functional class II). HF prevalence was 1.88% and incidence was 2.83 per 1,000 person-years. Regarding HF treatments, 66.1% were taking renin-angiotensin system inhibitors, 69.4% beta blockers, 31.2% aldosterone antagonists, and 7.5% sacubitril/valsartan. During the year of follow-up, 29.8% had HF decompensation which led to hospitalization (mean time to first event of 120.9 ± 72.5 days), 12.3% died, and 8.1% died during hospitalization. Events were more common among patients with type 2 diabetes. Hospitalizations for HF were more common in the DAPA-HF-like population.

CONCLUSIONS

In Spain, the population with HF is elderly and has many comorbidities. Approximately half of patients have HF with reduced left ventricular ejection fraction. There is room for improvement in HF management, particularly through the use of drugs that reduce both HF hospitalization and mortality, in order to reduce the burden of HF.

Talin rod domain-containing protein 1 (TLNRD1) is a novel actin-bundling protein which promotes filopodia formation

Talin is a mechanosensitive adapter protein that couples integrins to the cytoskeleton. Talin rod domain-containing protein 1 (TLNRD1) shares 22% homology with the talin R7R8 rod domains, and is highly conserved throughout vertebrate evolution, although little is known about its function. Here we show that TLNRD1 is an α-helical protein structurally homologous to talin R7R8. Like talin R7R8, TLNRD1 binds F-actin, but because it forms a novel antiparallel dimer, it also bundles F-actin. In addition, it binds the same LD motif-containing proteins, RIAM and KANK, as talin R7R8. In cells, TLNRD1 localizes to actin bundles as well as to filopodia. Increasing TLNRD1 expression enhances filopodia formation and cell migration on 2D substrates, while TLNRD1 down-regulation has the opposite effect. Together, our results suggest that TLNRD1 has retained the diverse interactions of talin R7R8, but has developed distinct functionality as an actin-bundling protein that promotes filopodia assembly.

Uveitis intermedia as the initial presentation of a primary lymphoma of the central nervous system

Primary central nervous system lymphoma is one of the most infrequent brain tumours, accounting for 3% of primary central nervous system neoplasms. In addition to its low prevalence, clinical presentation is usually nonspecific, leading to diagnostic delay. Intraocular involvement occurs in 15% of cases, and disease onset in this location is even rarer. We present a case of a patient with intermediate uveitis as the first clinical manifestation of this neoplasm.

Biochemical Characterization of the Integrin Interactome

More than 250 proteins are associated with the formation of integrin adhesion complexes involving a vast number of complex interactions between them. These interactions enable adhesions to serve as dynamic and diverse mechanosignaling centers. Our laboratory focuses on the biochemical and structural study of these interactions to help unpick this complex network. Here, we describe the general pipeline of biochemical assays and methods we use. The chapter is split into two sections: (1) protein production and characterization and (2) biochemical assays for the characterization of binding between full-length proteins and/or specific regions of proteins with other proteins, peptides, and phospholipids. The suite of assays we use routinely includes circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy for sample quality assessment, prior to biochemical analysis using NMR, fluorescence polarization (FP), microscale thermophoresis (MST), size-exclusion chromatography multiangle light scattering (SEC-MALS), and pulldown/cosedimentation-based approaches. The results of our analysis feed into in vivo studies that allow for the elucidation of the biological role of each interaction.

A quantitative assay to study the lipid selectivity of membrane-associated systems using solution NMR

The activity of membrane proteins and compounds that interact with the membrane is modulated by the surrounding lipid composition. However, there are no simple methods that determine the composition of these annular phospholipids in eukaryotic systems. Herein, we describe a simple methodology that enables the identification and quantification of the lipid composition around membrane-associated compounds using SMA-nanodiscs and routine 1H-31P NMR.

(1)H, (13)C and (15)N resonance assignments for the response regulator CheY3 from Rhodobacter sphaeroides

Rhodobacter sphaeroides has emerged as a model system for studies of the complex chemotaxis pathways that are a hallmark of many non-enteric bacteria. The genome of R. sphaeroides encodes two sets of flagellar genes, fla1 and fla2, that are controlled by three different operons. Each operon encodes homologues of most of the proteins required for the well-studied E. coli chemotaxis pathway. R. sphaeroides has six homologues of the response regulator CheY that are localized to and are regulated by different clusters of chemosensory proteins in the cell and have different effects on chemotaxis. CheY6 is the major CheY stopping the fla1 flagellar motor and associated with a cytoplasmically localised chemosensory pathway. CheY3 and CheY4 are associated with a membrane localised polar chemosensory cluster, and can bind to but not stop the motor. CheY6 and either CheY3 or CheY4 are required for chemotaxis. We are using NMR spectroscopy to characterise and compare the structure and dynamics of CheY3 and CheY6 in solution. We are interested in defining the conformational changes that occur upon activation of these two proteins and to identify differences in their properties that can explain the different functions they play in chemotaxis in R. sphaeroides. Here we present the (1)H, (13)C and (15)N assignments for CheY3 in its active, inactive and Mg(2+)-free apo form. These assignments provide the starting point for detailed investigations of the structure and function of CheY3.

Mapping the structure of amyloid nucleation precursors by protein engineering kinetic analysis

Understanding the early molecular mechanisms governing amyloid aggregation is crucial to learn how to prevent it. Here, we used a site-directed mutagenesis approach to explore the molecular mechanism of nucleation of amyloid structure in the N47A Spc-SH3 domain. The changes in the native state stability produced by a series of mutations on each structural element of the domain were uncorrelated with the changes in the aggregation rates, although the overall aggregation mechanism was not altered. Analysis of the thioflavin T initial rates based on a simple kinetic model allowed us to extract thermodynamic magnitudes of the precursor states of nucleation and map the regions of the protein participating in the structure of the amyloidogenic precursors. This structure differs from that of the folding transition state of the SH3 domains, strongly suggesting that the regions of the conformational landscape leading to amyloid formation are divergent from those leading to the native fold.

Early amyloidogenic oligomerization studied through fluorescence lifetime correlation spectroscopy

Amyloidogenic protein aggregation is a persistent biomedical problem. Despite active research in disease-related aggregation, the need for multidisciplinary approaches to the problem is evident. Recent advances in single-molecule fluorescence spectroscopy are valuable for examining heterogenic biomolecular systems. In this work, we have explored the initial stages of amyloidogenic aggregation by employing fluorescence lifetime correlation spectroscopy (FLCS), an advanced modification of conventional fluorescence correlation spectroscopy (FCS) that utilizes time-resolved information. FLCS provides size distributions and kinetics for the oligomer growth of the SH3 domain of α-spectrin, whose N47A mutant forms amyloid fibrils at pH 3.2 and 37 °C in the presence of salt. The combination of FCS with additional fluorescence lifetime information provides an exciting approach to focus on the initial aggregation stages, allowing a better understanding of the fibrillization process, by providing multidimensional information, valuable in combination with other conventional methodologies.

Environmental conditions affect the kinetics of nucleation of amyloid fibrils and determine their morphology

To understand and tackle amyloid-related diseases, it is crucial to investigate the factors that modulate amyloid formation of proteins. Our previous studies proved that the N47A mutant of the α-spectrin SH3 (Spc-SH3) domain forms amyloid fibrils quickly under mildly acidic conditions. Here, we analyze how experimental conditions influence the kinetics of assembly and the final morphology of the fibrils. Early formation of curly fibrils occurs after a considerable conformational change of the protein and the concomitant formation of small oligomers. These processes are strongly accelerated by an increase in salt concentration and temperature, and to a lesser extent by a reduction in pH. The rate-limiting step in these events has a high activation enthalpy, which is significantly reduced by an increase in NaCl concentration. At low-to-moderate NaCl concentrations, the curly fibrils convert to straight and twisted amyloid fibrils after long incubation times, but only in the presence of soluble species in the mixture, which suggests that the curly fibrils and the twisted amyloid fibrils are diverging assembly pathways. The results suggest that the influence of environmental variables on protein solvation is crucial in determining the nucleation kinetics, the pathway of assembly, and the final fibril morphology.

Construction and properties of a recombinant pseudorabies virus with tetracycline-regulated control of immediate-early gene expression

A study was carried out to determine whether altering the control of expression of the IE180 gene of pseudorabies virus (PRV), by replacing the IE180 promoter with the tetracycline-responsive promoter (Ptet), affects virus replication and virulence. This PRV-BT90 mutant virus was constructed by complementation and recombination in Hela Tet-Off cells. The virus yield produced by infection of Hela Tet-Off cells with PRV-BT90 was similar to that of the parental virus vBecker2. Viral replication of PRV-BT90 was reduced in Vero cells as reflected by a reduction of virus yield and plating efficiency compared to vBecker2. PRV-BT90 plaque formation in Hela Tet-Off cells was inhibited in the presence of doxycycline, whereas vBecker2 plaque formation was not affected. Subcutaneous infection of mice with the two viruses revealed a LD(50) higher than 10(6) TCID(50) for the PRV-BT90 mutant virus while the LD(50) was 178 TCID(50) for the vBecker2 parental virus.

Influence of ghrelin and growth hormone deficiency on AMP-activated protein kinase and hypothalamic lipid metabolism

Current evidence demonstrates that the stomach-derived hormone ghrelin, a potent growth hormone (GH) secretagogue, promotes feeding through a mechanism involving the short-term activation of hypothalamic AMP-activated protein kinase (AMPK), which in turn results in decreased hypothalamic levels of malonyl-CoA and increased carnitine palmitoyltransferase 1 (CPT1) activity. Despite this evidence, no data have been reported about the effect of chronic, central ghrelin administration on hypothalamic fatty acid metabolism. In the present study, we examined the differences in hypothalamic fatty acid metabolism in the presence and absence of GH, by using a model for the study of GH-deficiency, namely the spontaneous dwarf rat and the effect of long-term central ghrelin treatment and starvation on hypothalamic fatty acid metabolism in this animal model. Our data showed that GH-deficiency induces reductions in both de novo lipogenesis and beta-oxidation pathways in the hypothalamus. Thus, dwarf rats display reductions in fatty acid synthase (FAS) mRNA expression both in the ventromedial nucleus of the hypothalamus (VMH) and whole hypothalamus, as well as in FAS protein and activity. CPT1 activity was also reduced. In addition, in the present study, we show that chronic ghrelin treatment does not promote AMPK-induced changes in the overall fluxes of hypothalamic fatty acid metabolism in normal rats and that this effect is independent of GH status. By contrast, we demonstrated that both chronic ghrelin and fasting decreased FAS mRNA expression in the VMH of normal rats but not dwarf rats, suggesting GH status dependency. Overall, these results suggest that ghrelin plays a dual time-dependent role in modulating hypothalamic lipid metabolism. Understanding the molecular mechanism underlying the interplay between GH and ghrelin on hypothalamic lipid metabolism will allow new strategies for the design and development of suitable drugs for the treatment of GH-deficiency, obesity and its comorbidities.

The mammalian target of rapamycin as novel central regulator of puberty onset via modulation of hypothalamic Kiss1 system

The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that operates as sensor of cellular energy status and effector for its coupling to cell growth and proliferation. At the hypothalamic arcuate nucleus, mTOR signaling has been recently proposed as transducer for leptin effects on energy homeostasis and food intake. However, whether central mTOR also participates in metabolic regulation of fertility remains unexplored. We provide herein evidence for the involvement of mTOR in the control of puberty onset and LH secretion, likely via modulation of hypothalamic expression of Kiss1. Acute activation of mTOR by l-leucine stimulated LH secretion in pubertal female rats, whereas chronic l-leucine infusion partially rescued the state of hypogonadotropism induced by food restriction. Conversely, blockade of central mTOR signaling by rapamycin caused inhibition of the gonadotropic axis at puberty, with significantly delayed vaginal opening, decreased LH and estradiol levels, and ovarian and uterine atrophy. Inactivation of mTOR also blunted the positive effects of leptin on puberty onset in food-restricted females. Yet the GnRH/LH system retained their ability to respond to ovariectomy and kisspeptin-10 after sustained blockade of mTOR, ruling out the possibility of unspecific disruption of GnRH function by rapamycin. Finally, mTOR inactivation evoked a significant decrease of Kiss1 expression at the hypothalamus, with dramatic suppression of Kiss1 mRNA levels at the arcuate nucleus. Altogether our results unveil the role of central mTOR signaling in the control of puberty onset and gonadotropin secretion, a phenomenon that involves the regulation of Kiss1 and may contribute to the functional coupling between energy balance and gonadal activation and function.

A single mutation in an SH3 domain increases amyloid aggregation by accelerating nucleation, but not by destabilizing thermodynamically the native state

We investigated the relationship between thermodynamic stability and amyloid aggregation propensity for a set of single mutants of the alpha-spectrin SH3 domain (Spc-SH3). Whilst mutations destabilizing the domain at position 56 did not enhance fibrillation, the N47A mutation increased the rate of amyloid fibril formation by 10-fold. Even under conditions of identical thermodynamic stability, the aggregation rate was much higher for the N47A mutant than for the WT domain. We conclude that the N47A mutation does not change the apparent mechanism of fibrillation or the morphology of the amyloid fibrils, and that its amyloidogenic property is due to its effect upon the rate of the conformational events leading to nucleation and not to its overall destabilizing effect.

A model for the aggregation of the acylphosphatase from Sulfolobus solfataricus in its native-like state

Evidence is accumulating that normally folded proteins retain a significant tendency to form amyloid fibrils through a direct assembly of monomers in their native-like conformation. However, the factors promoting such processes are not yet well understood. The acylphosphatase from Sulfolobus solfataricus (Sso AcP) aggregates under conditions in which a native-like state is initially populated and forms, as a first step, aggregates in which the monomers maintain their native-like topology. An unstructured N-terminal segment and an edge beta-strand were previously shown to play a major role in the process. Using kinetic experiments on a set of Sso AcP variants we shall show that the major event of the first step is the establishment of an inter-molecular interaction between the unstructured segment of one Sso AcP molecule and the globular unit of another molecule. This interaction is determined by the primary sequence of the unstructured segment and not by its physico-chemical properties. Moreover, we shall show that the conversion of these initial aggregates into amyloid-like protofibrils is an intra-molecular process in which the Sso AcP molecules undergo conformational modifications. The obtained results allow the formulation of a model for the assembly of Sso AcP into amyloid-like aggregates at a molecular level.

In Vitro Evaluation of an Axial Flow Pump: Mock-Pump Interaction and an Approach to Control

Continuous flow pump support has emerged as an alternative therapy in patients with congestive heart failure. For long-term applications, it is important to have a control system that changes the pump function according to the physiological conditions of the patient, thereby preventing risk situations. In the early stages of development, the evaluation of control algorithms for artificial blood pumps can be done in vitro using cardiovascular mock systems.

A systemic cardiovascular mock loop was constructed and an axial flow pump was connected to it. The level of pump assistance was estimated using a pulsatility index (IPAo) obtained from the aortic pressure wave. An IPAo proportional-integral control system was implemented and its responses to peripheral resistance and systemic compliance changes were evaluated.

IPAo is an indicator of the assistance level of a continuous flow pump operated at constant speed.

The IPAo control algorithm responds by increasing the pump speed when peripheral resistance or systemic compliance is reduced. Control system operation around an IPAo fixed value provides a safety point for pump operation by maintaining aortic pressure pulsatility and avoiding ventricular suction. In vitro experimental results show that the IPAo can be taken into consideration in multiobjective control algorithm designs.

Acute porphyrias in the Argentinean population: a review

The porphyrias are a group of inherited metabolic disorders of heme biosynthesis which result from a partial deficiency in one of its seven specific enzymes, after its first and rate limiting enzyme, delta-aminolevulinic acid synthetase. They can be classified on the basis of their clinical manifestations into cutaneous, acute and mixed disorders. Acute intermittent porphyria (AIP) is the most common type of hepatic acute porphyrias, inherited as an autosomal dominant trait, caused by a defect in the gene which codifies for the heme enzyme porphobilinogen deaminase. Its prevalence in the Argentinean population is about 1:125,000. A partial deficiency in another enzyme, protoporphyrinogen oxidase, produces variegate porphyria (VP), the second acute porphyria most frequent in the Argentinean population (1:600,000). Here, we review all the mutations we have found in 46 AIP and 9 VP unrelated Argentinean patients. To screen for mutations in symptomatic patients, we have proposed a geneticresearch strategy.

Misoprostol for abortion at 9-12 weeks' gestation in adolescents

The objectives of the present clinical study were to evaluate the safety and efficacy of misoprostol (Cytotec), self-administered into the vagina for medical abortion, in adolescents under 18 years ofage. A group of 150 adolescents with gestations between 63 and 84 days, with previous written consent from the patient and parents or guardians, received 800 microg of vaginal misoprostol every 24 h, up to a maximum of three main doses, for abortion. Outcomes assessed included successful abortion (complete abortion without surgery), side-effects, decrease in hemoglobin, mean time of vaginal bleeding, mean expulsion time and mean time for the return of menses. Complete abortion occurred in 126/150 (84.0%, 95% confidence interval 77-89) patients. The frequencies of nausea and vomiting were statistically significantly higher when compared to those obtained for adult females. Vaginal bleeding lasted for 13.2 +/- 3.8 days (median 13 days, range 1-22 days). The mean expulsion time was 8.0 +/- 3.4 h (median 8 h, range 1-14 h) for all subjects who aborted after the first misoprostol dose. The mean drop in hemoglobin was statistically significant (p = 0.001), but without clinical relevance. From the high abortion rate obtained, we concluded that misoprostol alone is a valid method for terminating unwanted pregnancies at 10-13 weeks' gestation in adolescents under 18 years of age in the absence of mifepristone.

Misoprostol for abortion up to 9 weeks' gestation in adolescents

The objectives of the present clinical study were to evaluate the safety and efficacy of misoprostol (Cytotec) self-administered into the vagina for medical abortion in adolescents under the age of 18 years. After obtaining written consent from the patients and parents or guardians, a group of 150 adolescents with gestations between 35 and 63 days received 800 microg of vaginal misoprostol every 24 h, up to a maximum of three main doses, for abortion. Outcomes assessed included successful abortion (complete abortion without surgery), side-effects, decrease in hemoglobin, mean time of vaginal bleeding, mean expulsion time and mean time for the return of menses. Complete abortion occurred in 133/150 (88.7%, 95% confidence interval 82-93) patients. The frequencies of nausea, vomiting and diarrhea were statistically significantly higher when compared to those obtained for adult females. Vaginal bleeding lasted for 12.7 +/- 5.7 days (median 12 days, range 1-23 days). The mean expulsion time was 6.8 +/- 2.4 h (median 6 h, range 3-14 h) for those who aborted after the first misoprostol dose. The mean time for the return of menses, for those who aborted with misoprostol, was 34.7 +/- 3.4 days. The mean decrease in hemoglobin was statistically significant (p = 0.001), but had no clinical relevance. Taking into account the high abortion rate obtained, we could conclude that misoprostol alone is a valid method for terminating unwanted pregnancies in adolescents under the age of 18 years.

25 mg or 50 mg of oral methotrexate followed by vaginal misoprostol 7 days after for early abortion: a randomized trial

BACKGROUND

Several combinations of oral or intravenous methotrexate plus vaginal misoprostol have been used for early abortion with success rates varying widely. So far, any study has evaluated the efficacy and safety of lower doses of oral methotrexate followed by vaginal misoprostol for early abortion.

OBJECTIVES

To evaluate the efficacy and safety of methotrexate 25 or 50 mg orally and 800 micrograms of misoprostol vaginally 7 days after the methotrexate for abortion at </=56 days of gestation.

STUDY DESIGN

Three-hundred and ten pregnant women seeking elective abortion were randomly allocated to receive 25 mg (group I) or 50 mg (group II) of methotrexate orally and 800 micrograms of misoprostol vaginally 7 days after the methotrexate. The misoprostol dose was repeated 48 and 96 h later if the abortion did not occur. Outcome measures included successful abortion (complete abortion without requiring a surgical procedure), side effects and vaginal bleeding. Relative risks were used for the comparison between the outcomes from both treatment regimens.

RESULTS

In group I aborted 135/148 cases (91%, 95% CI 85, 95%), and 139/154 cases (90%, 95% CI 84, 94%) aborted in group II (relative risk [RR] = 1.01, RR 95% CI 0.94, 1.09).

CONCLUSIONS

The two treatment regimens showed the same efficacy and safety, so it would be advisable at least to use the smaller methotrexate dose, i.e. 25 mg.

[Intracranial mucocele. Report of a case]

Mucocele, usually associated to paranasal sinuses is defined as an abnormal accumulation and retention of mucous secretions. It usually presents with intraorbital or paranasal and rarely with pure neurological symptoms. We report a 41 years old male who presented with a history of supraorbital left headache, diplopia and proptosis. CT scans and magnetic resonance imaging showed an expansive mass in the right frontal sinus. The patient was operated, the presumptive preoperative clinical diagnosis of mucocele was confirmed and the lesion was drained. A postoperative CT scan confirmed the normal expansion of the frontal lobe.

Vaginal misoprostol 600 microg for early abortion

The objective of this study was to evaluate the efficacy and safety of the vaginal self-administration of 600 microg misoprostol up to a maximum administration of three doses in a 24-h period, one every 8 h, for abortion up to 9 weeks' gestation. A group of 90 voluntary women with gestations from 35 to 63 days participated in the study. All women who aborted received a single additional dose of 600 microg misoprostol. Outcome measures included successful abortion (complete abortion without requiring surgical procedure) and side-effects. Complete abortion occurred in 57/89 (64%, 95% confidence interval 53-74%) subjects. The mean expulsion time was 7.4 +/- 3.8 h (median 7.2 h, range 3-20 h) for all women who aborted within the first 24 h of the administration of misoprostol. Thirty-two cases failed to abort, 28 cases due to failure of the method, of which 24 had a negative cardiac rhythm after the third dose, and four cases due to the doctor's decision. The results obtained in this study led us to the conclusion that the 600-microg misoprostol dose regimen was not adequate to produce a high or an acceptable abortive efficacy.

Acute intermittent porphyria: characterization of two novel mutations in the porphobilinogen deaminase gene, one amino acid deletion (453-455delAGC) and one splicing aceptor site mutation (IVS8-1G>T)

A partial deficiency of Porphobilinogen deaminase (PBG-D) is responsible for acute intermittent porphyria (AIP). AIP is inherited in an autosomal dominant fashion, and the prevalence in the Argentinean population is about 1:125,000. Here, two new mutations and three previously reported were found in the PBG-D gene in 12 Argentinean AIP patients corresponding to 5 different families. To screen for AIP mutations in symptomatic patients, genomic DNA isolated was amplified in 2 Multiplex PCR reactions, then all coding exons and flanking intronic regions were sequenced. The new mutations are 453-455delAGC in exon 9 which results in the loss of an alanine residue at position 152, and one new point mutation in the splicing aceptor site in the last position of intron 8 (IVS8-1G>T) which leds to a 15 bp deletion because a cryptic site (first AG upstream) is used. Both mutations produce amino acid deletion without frameshift effect. To further characterize the 453-455delAGC mutation, the pKK-PBGD construct for the mutant allele was expressed in E. coli, the enzymatic activity of the recombinant protein was 1.3% of the mean level expressed by the normal allele. Finally, three missense mutations, previously reported, were identified in three unrelated families.

Early abortion with 800 micrograms of misoprostol by the vaginal route

The objective of this study was to confirm the effectiveness and safety of self-administration of misoprostol every 24 h, for abortion up to 9 weeks of gestation. A group of 720 volunteer subjects with gestations from 35 to 63 days received 800 micrograms of vaginal misoprostol every 24 h up to a maximum of three main doses for abortion. Outcome measures assessed included successful abortion (complete abortion without requiring surgery), side effects, decrease in hemoglobin, mean time of vaginal bleeding, and mean time of return of menses. Complete abortion occurred in 644 of 720 (89.4%, 95% CI 87, 92) subjects. The mean decrease in hemoglobin was statistically significant (p = 0.0001). There were 14 subjects with clinically significant decreases in hemoglobin, but only two required transfusions. Vaginal bleeding lasted 6.7 +/- 3.9 days, spotting 8.1 +/- 4 days, and total bleeding 14 +/- 5.3 days. Mean expulsion time was 8.0 +/- 3.4 h. Although mifepristone remains unavailable, given the low price and availability of misoprostol in > 72 countries of the world, this latter drug constitutes an abortion alternative, provided that a minimum clinical network is nearby or accessible.

Vaginal misoprostol for abortion at 10-13 weeks' gestation

OBJECTIVE

The effectiveness and safety of misoprostol have been reported for abortion up to 22 weeks' gestation. The objective of this study was to demonstrate the effectiveness and safety of self-administration of misoprostol every 12 h, without the need of postexpulsion systematic curettage, in late first-trimester abortions (10-13 weeks' gestation).

METHODS

A group of 180 women with gestations from 64 to 91 days, self-administered 800 micrograms of vaginal misoprostol every 12 h for a maximum of three doses without performing postexpulsion systematic preventive curettage. Outcome measures included successful abortion (complete and incomplete abortion without requiring a surgical procedure), side-effects, mean expulsion time and vaginal bleeding.

RESULTS

Successful abortion occurred in 153/180 (85%) subjects (95% confidence interval (CI) 79-90). The decrease of hemoglobin was statistically significant (p = 0.0001) but clinically unimportant: 12.1 mg/dl (SD 1.1) before treatment and 11.7 mg/dl (SD 1.1) afterwards. The mean expulsion time for patients who aborted after the first dose was 8.3 +/- 3.6 h (median 8 h, range 2-12 h). Vaginal bleeding lasted 6 +/- 3 days, spotting 7 +/- 3 days and total bleeding 13 +/- 4 days. The median dose of misoprostol administered was 1780 micrograms (range 1400-3000 micrograms).

CONCLUSIONS

The high degree of acceptability, its efficacy and the fact that postabortion systematic curettage was not needed make misoprostol a suitable alternative to the currently available methods for termination of pregnancy at 10-13 weeks' gestation.

A randomized trial of the effect of moistening misoprostol before vaginal administration when used with methotrexate for abortion

A prospective multicenter, randomized trial was performed to evaluate if moistened misoprostol results in a more rapid abortion and a higher rate of complete abortion compared with dry misoprostol when administered intravaginally for medical abortion after methotrexate. A total of 240 pregnant women < or = 49 days gestation seeking elective abortion received 50 mg/m2 methotrexate intramuscularly followed 5-6 days later by 800 micrograms misoprostol vaginally. The misoprostol dose was repeated in 1-2 days if the abortion did not occur. Group 1 moistened the misoprostol before administration and group 2 used dry tablets. There was no statistically significant difference in the cumulative rate of abortion after the first misoprostol dose (73.0% vs 71.3%, p = 0.87), second misoprostol dose (84.1% vs 81.1%, p = 0.65), or by 35 days after methotrexate administration (95.2% vs 91.8%, p = 0.40) between groups 1 and 2, respectively. The proportion of subjects with embryonic cardiac activity 2 weeks after methotrexate injection was greater in group 2 (5.7%, 95% confidence interval [CI] 1.0%, 9.9%) than in group 1 (2.4%, 95% CI 0%, 5.0%), although not statistically significant (p = 0.21). The immediate success rate in Pittsburgh was greater, albeit not statistically, for the women that moistened the misoprostol (87% vs 76%, p = 0.19); these rates were also not statistically different in Havana (82% vs 86%, p = 0.62). The rate of side effects after methotrexate was not different between groups but women in group 1 had significantly more diarrhea (36% vs 21%, p = 0.02) and fever/warmth/chills (44% vs 30%, p = 0.04). Moistening misoprostol before vaginal administration in a medical abortion regimen with methotrexate does not statistically improve efficacy. This trial demonstrates the importance of prospective, randomized studies to prove the relative efficacy of any medical abortion treatment regimen.

Vaginal misoprostol for late first trimester abortion

A group of 120 women with gestations from 64 to 84 days received 800 micrograms of vaginal misoprostol every 24 h for a maximum of three doses without performing postexpulsion systematic preventive curettage. Outcome measures included successful abortion (complete abortion without requiring a surgical procedure), side effects, and mean time of expulsion and vaginal bleeding. Complete abortion occurred in 104 of 120 (87%, 95% CI 79, 92) subjects. The decrease of hemoglobin was statistically significant (p = 0.0001) but clinically unimportant: 12.2 mg/dL (SD 1.1) before treatment and 11.6 mg/dL (SD 1.0) after treatment. Statistically significant differences were found only between the success rates for white women in comparison with nonwhite women, in which case the success rates were higher for white than for nonwhite women. Vaginal bleeding lasted 8 +/- 5 days, spotting 4 +/- 3, and total bleeding 12 +/- 4 days. The acceptable expulsion time, the fact that postabortion systematic curettage was not needed, the clinically insignificant hemoglobin loss, and the success rate obtained show that misoprostol administered vaginally may be a valid method for interrupting gestations of 10-12 weeks.

Oral methotrexate and vaginal misoprostol for early abortion

A prospective trial including 300 pregnant women seeking elective abortion was conducted to evaluate the safety and efficacy of methotrexate and misoprostol for abortion at < or = 63 days' gestation. Subjects received methotrexate 50 mg orally and were randomly allocated to receive 800 micrograms of misoprostol vaginally 3, 4, or 5 days after administration of the methotrexate. The misoprostol dose was repeated 48 and 96 h later if abortion did not occur. Outcome measures included successful abortion (complete abortion without requiring a surgical procedure) and side effects. Complete abortion occurred in 273 of 300 patients (91%, 95%, CI 87, 94%) patients. No significant statistical differences were found in the success rates when misoprostol was given days 3, 4, or 5 after the administration of methotrexate (p = 0.69). Vaginal bleeding lasted 7.1 +/- 3.8 days, spotting 4.1 +/- 2.5 days, and total bleeding 11.2 +/- 4.1 days. Side effects for methotrexate were minimal, whereas, for misoprostol they were mild and transient except for pain. The use of methotrexate and misoprostol together could be an alternative to the intramuscular use of methotrexate or the use of antiprogestins and prostaglandin for medical abortion.

Misoprostol 3, 4, or 5 days after methotrexate for early abortion. A randomized trial

A randomized trial was conducted including 287 pregnant women seeking elective abortion to compare the efficacy of misoprostol given 3, 4, or 5 days after methotrexate for abortion at < or = 63 days' gestation. Subjects received 50 mg/m2 methotrexate intramuscularly and were randomly allocated to self-administer vaginally 800 micrograms of misoprostol 3, 4, or 5 days after the methotrexate. The misoprostol dose was repeated 48 and 96 h later if the abortion did not occur. Outcome measures included successful abortion (complete abortion without requiring a surgical procedure), and side effects. Eighty-six cases (93%; 95% confidence interval [CI] 85%-97%) aborted in Group I; 90 cases (92%; 95% CI 84%-96%) aborted in Group II (relative risk [RR] = 1.09; RR 95% CI 0.38-3.14); and 89 (93%; 95% CI 86%-97%) cases aborted in Group III (RR = 0.97; RR 95% CI 0.33-2.87). No significant statistical differences were obtained for the success rates when misoprostol was given days 3, 4, or 5 after the administration of methotrexate (p = 0.97) nor with any of the characteristics of the subjects. Complete abortion occurred in 265/287 (92%; 95% CI 89%-95%) patients. Twenty-two cases (8%; 95% CI 5%-11%) resulted in failure. Side effects for methotrexate were minimal while for misoprostol they were moderate. This combination could be an alternative to surgical abortion or the use of antiprogestins and prostaglandins for medical abortion.

The use of misoprostol for abortion at < or = 9 weeks' gestation

OBJECTIVE

To verify the efficacy and safety of misoprostol for abortion at < or = 63 days' gestation.

METHOD

A total of 175 women seeking elective abortion at < or = 63 days' gestation received 800 micrograms of misoprostol vaginally. This dose was repeated at 48 and 96 h if abortion did not occur. Afterwards, up to three additional 600- or 400-micrograms doses of misoprostol were administered if the uterus was not empty, as judged by ultrasound. Outcome measures included successful abortion (complete abortion without requiring a surgical procedure), side-effects and vaginal bleeding.

RESULTS

Complete abortion occurred in 161/175 (92.0%; 95% CI 87-96%) subjects and 14/175 (8.0%; 95% CI 4-13%) cases failed. The immediate success rate was 77.7% with the first dose, 13.7% with the second dose and 0.6% with the third dose. The decrease in hemoglobin was statistically significant (p = 0.009) but without clinical relevance; before treatment: 11.94 mg/dl (SD 1.60) and after treatment: 11.64 mg/dl (SD 1.08). No significant differences were obtained between success rates and failures in relation to age, gravidity, parity, previous abortions, race, gestational age and side-effects. The third main dose of misoprostol showed very little efficacy. Vaginal bleeding lasted 5.5 +/- 2.8 days, spotting 5.7 +/- 3.1 days and total bleeding 11.2 +/- 3.0 days.

CONCLUSIONS

The success percentage attained shows that 800 micrograms of misoprostol administered vaginally effectively causes abortion at < or = 63 days' gestation.

The use of misoprostol for termination of early pregnancy

Misoprostol is a prostaglandin analogue with uterotonic properties. A group of 141 women with less than 70 days of pregnancy received up to 3 doses of 800 micrograms of misoprostol every 48 hr. Failure was defined as the need for surgical abortion and success as the complete expulsion of the products of conception pharmacologically. In total, 132 cases (93.6%, 95% CI 89.4-97.8) aborted pharmacologically and 9 cases (6.4%) failed. The decrease in hemoglobin was statistically significant (p = 0.001) but without clinical repercussions; before treatment: 11.95 mg/dI (SD 1.19) and after: 11.14 (SD 1.20). Statistically significant differences were not noticed between success rates and failures in relation to gravidity, parity, previous abortions, race, or age, but were noticed with a gestation upwards of 9 weeks (p = 0.01). The third dose of misoprostol showed very little efficacy. The convenience of using more frequent doses and shortening the treatment, combined with different routes of administration, are discussed.

Bone mass in Parkinson's disease: a study with three methods

Recent reports suggest the presence of osteopenia in a high percentage of patients with Parkinson's disease (PD). These data contrast with previous reports of our group, perhaps due to the different methods used. We studied bone mass in 52 PD patients (28 males, 24 females) and in 80 age- and sex-matched controls (40 males, 40 females) who had no other disease that could affect bone mass. We measured the totally body bone mineral content (TBBMC) and the ultrasound bone velocity (UBV) of transmission in phalanx, and performed metacarpal radiogrammetry with computerized radiography (CCT). We also measured serum levels of total alkaline phosphatase and tartrate-resistant acid phosphatase, which were significantly increased in PD patients compared with controls (P < 0.0001). TBBMC was significantly lower in males (P < 0.05) and females (P < 0.05) with PD with respect to their controls. CCT did not differ significantly between the study groups. UBV was significantly lower in males with PD (P < 0.005), but similar in female PD and controls. These data suggest that the changes reported in bone mass in PD patients can depend on the sex and the study methods. We only found severe osteopenia in one male (3.6%) and five females (20.8%) with PD according to z-score. Only in women was no relationship found between TBBMC and severity of PD.

Beta-2-microglobulin in diseases with high bone remodeling

Beta2-microglobulin has been observed to behave as a biological marker of bone remodeling. We measured beta2-microglobulin and tartrate-resistant acid phosphatase (TRAP), a specific biological marker of bone remodeling, in 225 women: healthy premenopausal controls, healthy postmenopausal control, and patients with diseases characterized by enhanced bone turnover (postmenopausal osteoporosis, primary hyperparathyroidism, primary hyperthyroidism, polyostotic Paget's bone disease), and in other Paget's group before and after calcitonin treatment. Beta2-microglobulin levels differed significantly between the healthy premenopausal women (n = 20) compared with all the other groups. However, beta2-microglobulin levels did not differ significantly between healthy postmenopausal women (n = 38) and patient's with Paget's bone disease (n = 40)(P = 0.5095), or between women with postmenopausal osteoporosis (n = 30) and women with hyperthyroidism (n = 20)(P = 0.7890). TRAP concentrations differed significantly in all the groups paired except for women with Paget's bone disease and women with either hyperparathyroidism or hyperthyroidism (P = 0.5179 and 0.6993, respectively); likewise, TRAP levels did not differ significantly between the women with hyperparathyroidism and those with hypothyroidism (P = 0.7804). After calcitonin treatment, there was a 22% increase in beta2-microglobulin, a 17% decrease in TRAP, and a 39% decrease in alkaline phosphatase, all of which were significant at P < 0.0001. Our findings indicate that serum beta2-microglobulin, like osteocalcin, behaves as a biological marker of remodeling in a number of diseases with enhanced bone remodeling but not in Paget's bone disease.

Evidence that the loss of bone mass induced by GnRH agonists is not totally recovered

There is disagreement as to whether the loss of bone mass induced by GnRH agonists is reversible. In part, the differences of opinion might be attributed to the fact that the influence of weight and seasonal changes on bone mass is often overlooked. Taking into consideration weight and seasonal changes in bone mass, total (TBBMC) and regional body bone mineral content were measured in 38 women treated with GnRH agonists for 6 months for endometriosis or leiomyomata. Measurements were made at the onset of treatment, at 6 months of treatment and at 6 months after finishing treatment. TBBMC was corrected for body weight. Body weight had increased significantly at 6 months of treatment (P = 0.0175). Regional bone mineral content showed the following: limbs, no changes; head, significantly lower at 12 months than at baseline (P = 0.0036) and at 6 months (P = 0.0343) of therapy; trunk, significantly lower at 6 months (P = 0.0002) compared to baseline, but the values at 1 year were not significantly different from either the baseline or the 6-month values; pelvis, the same pattern of change as in the trunk (P = 0.0349). TBBMC was significantly lower at 6 months of treatment (P < 0.0001) and at 1 year (P = 0.0162). TBBMC adjusted for weight experienced the same changes as unadjusted bone mineral content (P < 0.0001 and P < 0.0009 at 6 months and 1 year, respectively). Our findings indicate that the bone mass lost with GnRH treatment had not been restored 6 months after discontinuing treatment.

[Type I familial pseudohypoparathyroidism: clinical and hormonal study]

Pseudohypoparathyroidism is a rare disease characterized by a target tissue resistance to the action of the parathyroid hormone (PTH). Frequently, others hormonal disorders can be associated. We report a family with pseudohypoparathyroidism type I, and discuss the clinical-hormonal alterations founded; it is emphasized that while there were no phenotypical differences among the family members; from the hormonal features point of view, some differences do exist, and several degrees of peripheral resistance were noted.