Plasmocitoma solitario de costilla como presentación inicial de mieloma múltiple: reporte de un caso / Lone rib plasmacytoma as a presentation of initial multiple myeloma: a case report

Resumen Introducción: El 50% de los tumores de pared torácica son malignos, dentro de los que destaca el plasmocitoma de costilla. Objetivo: Presentar un caso clínico que debutó inicialmente como un plasmocitoma de costilla, y que terminó presentándose como mieloma múltiple. Materiales y Método: Registro clínico de un paciente sometido a resección de tumor de parrilla costal. Resultados: Paciente masculino de 58 años, con un año de dolor costal, asociado a aumento de volumen a nivel de la octava costilla derecha en línea media axilar, indurada. TC de tórax que demuestra imagen sugerente de plasmocitoma de 79 × 44 mm. Se realiza resección quirúrgica, con instalación de malla de prolene en el defecto. Biopsia diferida con compromiso neoplásico por lesión monoclonal de células plasmáticas. Se complementa estudio con biopsia de médula ósea confirmando mieloma múltiple. Se inicia tratamiento con quimioterapia adyuvante. Conclusiones: El plasmocitoma óseo solitario es una entidad de baja frecuencia, que se asocia a la presencia de mieloma múltiple. Es por esto que al momento de la sospecha se hace necesario descartar su presencia, con el fin de mejorar el pronóstico del paciente.

Introduction: Up to 50% of chest wall tumors are malignant; among which rib plasmocytoma stand out. Aim: Showcase a clinical case that debuted as a rib plasmacytoma, and that ended up presenting as Multiple Myeloma. Materials and Method: Records of a patient with resection of chest wall tumor. Results: Male patient of 58 years, with one year of costal pain, associated with an indurated increase in volume at the level of the eighth right rib in the mid-axillary line. Chest CT scan demonstrated a suggestive image of plasmacytoma of 79 × 44 mm. Surgical resection was performed, with prolene mesh installation in the defect. Biopsy showed neoplastic compromise due to monoclonal lesion of plasma cells. Study is complemented with bone marrow biopsy confirming multiple myeloma. The patient was treated with adjuvant chemotherapy. Conclusions: Solitary bone plasmacytoma is a low frequency entity, which is associated with the presence of multiple myeloma. At the moment of suspicion, it is necessary to rule out their presence, in order to improve the patient's prognosis.

Pharmacokinetic variations of nimesulide in mongrel dogs according to age.

The purpose of this research was to investigate the possible variations to the pharmacokinetics of nimesulide by the effect of age using an animal model. An experimental, analytical, prospective and longitudinal study in five dogs, from birth to 730 days of age was carried out. Nimesulide blood levels were measured in different months; concentrations were determined by HPLC-UV. Pharmacokinetic parameters were calculated by using the WinNonlin software. There were statistically significant differences (p <0.05) in most of the pharmacokinetic parameters between study of 6 months against the other three studies in different ages. Changes in the pharmacokinetic parameters of nimesulide as a result of age, are determined by the growing and maturation of the animals. Resulting data suggest that nimesulide can be used safely as a long-term analgesic in dogs, but, the dosing regimens in humans should be different when administered at early age.

Enfermedad de Rosai-Dorfman mamario / Mammary Rosai Dorfman disease

Background: Rosai Dorfman disease is uncommon and consists in a benign fibrous and hematopoietic tissue proliferation, usually located in the head or neck. It is self-limited and the treatment is the surgical excision of the lesion. Case Report: We report a 69 years old woman consulting for a palpable right breast nodule with a mammography and mammary ultrasound informed as BIRADS 4 and 5, respectively. A core biopsy was informed as a mammary Rosai Dorfman disease. Two years later, due to a lesion growth, the patient was subjected to a partial mastectomy. The pathological study of the surgical piece confirmed the diagnosis of the core biopsy. This disease may resemble a malignant disease and the clue for its diagnosis is the pathological study.

Introducción: La enfermedad de Rosai Dorfman es una entidad infrecuente, que consiste en la proliferación benigna del tejido fibroso y hematopoyético ubicado generalmente en cabeza y cuello. Se trata de una enfermedad benigna, autolimitada, cuyo tratamiento generalmente se limita a la resección quirúrgica, con elevada tasa de recidiva. Objetivo: Exposición de un caso de Enfermedad de Rosai Dorfman mamario, inicial-mente sugerente de patología maligna. caso clínico: Mujer 69 años derivada de atención primaria por nódulo palpable en mama derecha, mamografía y ecografía mamaria BIRADS 4 y 5, respectivamente. Biopsia Core informa Enfermedad de Rosai Dorfman mamaria. A los dos años de diagnóstico se objetiva lesión de mayor tamaño. Se realizó mastectomía parcial con biopsia de pieza quirúrgica compatible con diagnóstico de Biopsia Core previa. Discusión: La similitud clínica de esta enfermedad con patologías malignas mamarias, asociado a su baja prevalencia, dificultan la pesquisa de casos como el expuesto. En los estudios de imágenes raramente se sospecha. La clave del diagnóstico son los hallazgos histológicos en el que característicamente se observa emperipolesis con tinciones inmunohistoquímicas positivas para S 100 y negativo para CD 1. Dado que es una enfermedad benigna y autolimitada su tratamiento generalmente se limita a la resección quirúrgica. Este permite extirpar el tumor en estudio, realizar el diagnóstico, y aliviar la sintomatología producida por el efecto masa de la lesión. A pesar de lo anterior la recidiva es alta, por lo que el seguimiento debe ser a largo plazo.

Effect of morphine and lacosamide on levels of dopamine and 5-HIAA in brain regions of rats with induced hypoglycemia.

The study aimed to determine the effect of morphine and lacosamide on levels of dopamine and 5-HIAA in a hypoglycemic model. Female Wistar rats (n = 30), mean weight of 180 g were treated as follow: Group 1 (control) received 0.9% NaCl, Group II; morphine (10 mg kg(-1)), Group III; lacosamide (10 mg kg(-1)), Group IV; insulin (10 U.I. per rat), Group V; morphine (10 mg kg(-1))+insulin, Group VI; lacosamide (10 mg kg(-1))+ insulin. All administrations were made intraperitoneally every 24 h, for 5 days. Animals were sacrificed after the last dose to measure the levels of glucose in blood; dopamine and 5-HIAA in cortex, hemispheres and cerebellum/medulla oblongata regions. Levels of glucose decreased significantly in animals treated with morphine, lacosamide and all groups that received insulin alone or combined with respect to control group. Levels of Dopamine diminished significantly in cortex and increased significantly in hemispheres of animals that received morphine. In cortex, 5-HIAA increase significantly in the groups treated with morphine, morphine+insulin and lacosamide+insulin, however a significant decrease of the same substance was witnessed in cerebellum and medulla oblongata of animals that received morphine or lacosamide plus insulin. GSH increased significantly in cortex and cerebellum/medulla oblongata of animals treated with morphine and lacosamide alone or combined with insulin. Lipid peroxidation decreased significantly in cortex and cerebellum/medulla oblongata of groups that received lacosamide alone or combined with insulin. These results indicate that hypoglycemia induced changes in cellular regulation while morphine and lacosamide are accompanied by biochemical responses.

Hamartoma e hiperplasia estromal pseudoangiomatosa de la mama, diagnósticos diferenciales infrecuentes de cáncer de mama / Hamartoma and nodular pseudoangiomatous stromal hyperplasia: differential diagnosis

Introducción: Los hamartomas y la hiperplasia estromal pseudoangiomatosa nodular (PASH) son entidades infrecuentes en la patología tumoral mamaria, sin embargo, pueden simular al cáncer de mama. La única herramienta certera preoperatoria es la biopsia. El tratamiento quirúrgico es curativo con bajo índice de recurrencia. Objetivo: El objetivo de este trabajo es exponer un caso de hamartoma mamario con PASH asociado cuya presentación inicial fue sugerente de probable patología maligna. Caso Clínico: Mujer de 44 años, ingresa a controles por probable patología mamaria maligna, la mamografía fue informada como BIRADS 0, la ecografía mamaria como BIRADS US: 5, la biopsia CORE informó PASH. Se realizó mastectomía parcial objetivando en la biopsia diferida un hamartoma mamario con extensa hiperplasia estromal pseudoangiomatosa. Discusión: Los hamartomas y la PASH son patologías sin presentación clínica específica, los hallazgos radiológicos del hamartoma pueden ser patognomónicos, no así en la PASH; en el caso expuesto el estudio anatomopatológico demostró una asociación de estas patologías, la cual se describe desde un 16 por ciento a un 71 por ciento de los casos de hamartoma mamario. El análisis de toda la pieza quirúrgica es fundamental para establecer un diagnóstico definitivo.

Introduction: Hamartoma and nodular pseudoangiomatous stromal hyperplasia (PASH) are inusual breast tumor entities, however, can simulate breast cancer. The only accurate tool is preoperative biopsy. Surgical treatment is curative with low recurrence rate. Objective: To present a case of mammary hamartoma associated with PASH whose initial presentation was suggestive of probable malignancy. Case Report: Woman, 44 years old, admitted to controls because of probable malignant breast disease, mammography was reported as BIRADS 0, breast ultrasound as BIRADS U.S: 5, CORE biopsy reported PASH. Partial mastectomy was performed. On delayed biopsy mammary hamartoma with extensive stromal hyperplasia pseudoangiomatosa was diagnosed. Discussion: PASH and hamartomas are diseases with no specific clinical presentation, radiological findings may be pathognomonic of hamartoma, while not in PASH. In the reported case the pathological study showed an association of these conditions, described in a 16% to 71% breast hamartoma cases. The analysis of the entire surgical specimen is essential for a definitive diagnosis.

A reliable method to quantify sildenafil and its metabolite N-demethylsildenafil by HPLC in plasma of children.

The aim of this study was to develop a simple method for quantifying plasma levels of sildenafil and its metabolite by liquid chromatography with a C18 reverse-phase column and UV detection. For both compounds, linearity was assessed in the range from 10 and 1 000 ng · ml-1 and had correlation coefficients of r=0.995 and r=0.997 for sildenafil and its metabolite, respectively. The inter- and intra-day coefficients of variation was<5.3%. The limits of detection and quantification were 1 and 10 ng · ml-1. Drug levels were determined satisfactorily in two patients. A simple and reliable method was developed for use in children with Pulmonary Arterial Hypertension under treatment with sildenafil.

Preparation and evaluation of unitary doses of propafenone used in children with supraventricular tachycardia: a pilot study.

PURPOSE: The aim was to prepare and evaluate unitary doses of propafenone (UDP) used in children with supraventricular tachycardia. METHODS: UDP were prepared from four brands of tablets at doses of propafenone, 11, 25 and 90 mg, used in the Cardiology Service of this Institute. The stability of doses was determined at 20±5°C and 40°C for up to day 30. Besides, a weight variation test was performed. Plasma levels of propafenone were determined at steady state in 3 children diagnosed with supraventricular tachycardia under treatment with UDP. Concentrations of drug in blood were measured using a high pressure liquid chromatography method, previously validated. RESULTS: The stability of UDP, showed no significant statistical differences (p > 0.05) between doses or brands up to day 30, at both temperatures. The coefficient of variation from the weight variation was less than 6%. The plasma levels of propafenone at steady state were: patient 1, 31.57 ng/ml; patient 2, 226.46 ng/ml; and patient 3, 221.29 ng/ml. CONCLUSIONS: The actual administered dose for the patients could vary up to 6%, and doses prepared from different brands of tablets remain stables for up to day 30 at both temperatures. UDP is a temporal, safe and alternative option when pediatrics formulation of this drug is lacking.

Effect of nicotine on ATPase, catalase and calcium levels in the presence of oligoelements in brain regions of young rats.

UNLABELLED: The effect of nicotine on membrane alterations and fluidity changes in very young models remains unclear. The aim of this study was to evaluate the effect of nicotine on total ATPase, H(2)O(2) and calcium in brain of young rats in the presence of oligoelements. Male Wistar rats (weight 80 g) received intraperitoneally either a single dose or repeated doses for 4 days as follows: Group 1 (control) NaCl 0.9%; group 2 nicotine (1mg/kg); group 3 oligoelements (50 µl); and group 4 nicotine (1mg/kg) + oligoelements (50 µl). The brain regions (cortex, hemispheres and cerebellum + medulla oblongata) of each rat were then obtained to measure the concentrations of total ATPase, H(2)O(2) and calcium using spectrophotometric methods. RESULTS: Total ATPase increased significantly (p < 0.05) in groups treated with oligoelements in repeated doses in hemisphere region, and in groups that received oligoelements + nicotine in single or repeated doses in medulla oblongata. Catalase showed significant decreased in cerebellum/medulla oblongata. Results suggest that nicotine induces changes in membrane fluidity in brain of young rats, and that ATPase could be a biomarker of nicotine consumption in young subjects.

Experimental models of developmental hypothyroidism.

Hypothyroidism is a systemic disease resulting from either thyroid gland's anatomical and functional absence or lack of hypophyseal stimulation, both of which can lead to deficiency in thyroid hormone (TH) production. TH is essential for human and animal development, growth, and function of multiple organs. Children with deficient TH can develop alterations in central nervous system (CNS), striated muscle, bone tissue, liver, bone marrow, and cardiorespiratory system. Among the clinical outlook are signs like breathing difficulty, cardiac insufficiency, dysphagia, and repeated bronchial aspiration, constipation, muscle weakness, cognitive alterations, cochlear dysfunction, reduced height, defects in temperature regulation, anaemia, jaundice, susceptibility to infection, and others. Experimental and clinical studies have shown that TH is very essential for normal brain development. Other research work based on mice pointed out that a reduced level of TH in pregnant mother leads to congenital hypothyroidism in animal models and it is associated with mental retardation, deep neurologic deficiency that impacts on cognitive, learning, and memory functions. The principal experimental model studies that have focused on hypothyroidism are reviewed in this study. This is important on considering the fact that almost all animal species require thyroid hormones for their metabolism.

Effect of flutamide and two novel synthetic steroids on GABA, glutamine and some oxidative stress markers in rat brain and prostate.

Flutamide is a steroid used to treat androgen-dependent disorders and as antiepileptic, but it induces a number of non-desirable side effects. This work was aimed at assaying the effect of flutamide and two novel synthetic steroids on the levels of GABA, glutamine and oxidative stress markers. Male Wistar rats (weight 180 g) received a single diazepam dose (5 mg/kg) 30 min prior to sacrifice (group A). Group B, flutamide; group C, 16ß-methyl-17α-benzoyloxypregnen-4-en-3,20-dione; group D, estrone-3-hemisuccinate; group E, testosterone; group F, progesterone; all administered intraperitoneally at 10 mg/kg, daily for 3 days. Brain and prostate were obtained to assess lipid peroxidation (TBARS), Na(+) , K(+) ATPase activity, reduced glutathione (GSH), γ-amino butiric acid (GABA), glutamine and serotonin (5-HT) concentrations through spectrophotometry, fluorescence and HPLC. GABA levels increased and glutamine decreased in group A (P < 0.05). Total ATPase activity increased in group F and TBARS decreased in group B (P < 0.05). GSH decreased in A, B and C groups. 5-HT increased in group A and the prostate weight was increased in group E. The conclusion is that 16ß-methyl-17α-benzoyloxypregnen-4-en-3,20-dione may be considered novel and promising to treat androgen-dependent diseases and epilepsy, since it showed an antioxidant effect and seemed to impair the GABAergic and serotonergic metabolism.

Effect of prostaglandin E1 (PGE1) and sildenafil on serotonin metabolism and some oxidative damage markers in rat prostate gland and brain.

The aim of this study was to evaluate the effect of sildenafil and prostaglandin E1 (PGE1) (drugs used in erectile dysfunction) on production of free radicals in prostate and brain of rat. A single dose of sildenafil (10 mg kg(-1) ) and PGE1 (20 µg kg(-1) ) was given to Sprague-Dawley rats (300 g weight) intraperitoneally. The levels of testosterone were measured in blood. Their brains and prostate glands were separated to measure lipid peroxidation, Na(+) and K(+) ATPase activity, reduced glutathione (GSH) and serotonin levels, by means of validated methods. The levels of testosterone increased slightly in animals treated with sildenafil and PGE1. The activity of total ATPase was increased in the prostate of animals treated with sildenafil + PGE1 but decreased in those that received sildenafil alone. PGE1 caused significant diminution of GSH levels in both organs. Sildenafil increased the levels of serotonine in brain, whereas in prostate they decreased instead. Our results suggest that sildenafil induced changes in GSH levels as well as in the serotonergic metabolism, alone or with PGE1 in prostate and brain, respectively. Thus, the combination therapy may be ideal to sustain the biochemical balance due to biphasic stimulation on brain and prostate.

Reversibility of hepatic histological damage after surgical temporary obstruction of the common bile duct in a murine model.

The reversibility of hepatic histological damage after restoring bile flow in a murine model was assessed. 25 male Balb C mice (25-35 g, age 6 weeks) were divided into 5 groups and their common bile duct (CBD) fastened to obstruct the release of gall bladder and liver contents. Group I, CBD untied at day 10, group II at day 15, and groups III and IV at days 20 and 30, respectively. Hematoxilin-eosin stained liver slices were analysed 0, 5, 10 and 20 days after restoring bile flow. Group I showed slight histological lesions (second stage), as cholangiolar bile pigment concretion, pericholangiolar and portal collagen accumulation; group II, mild lesions (third stage), as cholangiolar hamartomatous proliferation and bile duct portal fibrosis; group III showed severe lesions (fourth stage), as loss of functional parenchyma, and also the second and first stage lesions. Group IV died before 30 days. First stage corresponds to absent lesions (control group). Group I recovered totally, group II recovered only from slight lesions and group III had irreversible damage. Severity of lesions increased gradually and accumulatively, irreversible hepatic damage was achieved at 20 days and is deadly at 30 days. Our model of temporary CBD obstruction was suitable to assess reversibility of hepatic histological damage.

Effect of orlistat on lipid peroxidation, Na+, K+ ATPase, glutathione and serotonin in rat brain.

The aim of this study was to evaluate the effect of orlistat, a drug used in weight loss, on 5-HT and indicators of oxidative stress in rat brain. Orlistat, 12 mg/kg was administered to Wistar rats as single dose or successive doses on 3 consecutive days. Blood glucose and oxidative stress indicators were detected by measurement of lipid peroxidation, Na+, K+ ATPase, glutathione and serotonin levels using previous validated methods. The levels of glucose decreased in rats receiving successive doses. The activity of Na+, K+ ATPase and total ATPase was reduced in rats receiving successive doses, while the level of lipid peroxidation increased slightly in both groups. Glutathione underwent significant reduction in the successive doses group (p < 0.05). 5-HT increased significantly after single dose treatment (p < 0.05). Orlistat can induce pro-oxidant effects in the brain due to alteration of serotonergic metabolism and the reduction of glutathione.

Effects of marijuana and diazepam on lipid peroxidation, Na+ , K+ ATPase, and levels of glutathione and 5-HTP in rat brain.

Our aim was to evaluate the effects of marijuana (Mar) and diazepam (Dz) on lipid peroxidation (TBARS), Na + , K + ATP ase activity, levels of glutathione (GSH) and 5-hydroxytryptophan (5-HTP). Male Wistar rats were given a single dose per group: extract of Mar (100 microL/kg), Dz (5 mg/kg), Mar plus Dz, and NaCl for control. Sixty mins after treatment, animals were sacrificed, and their brains extracted and homogenised to measure GSH, TBARS and 5-HTP levels. Na + , K + ATP ase and total ATP ase activities. GSH and TBARS did not show differences respect to controls. Na + , K + ATP ase activity was similar as well. However, groups treated with Mar, total ATPase activity decreased significantly (p < 0.05). Levels of 5-HTP decreased significantly (p = 0.0001) in rats treated either with Mar and or Dz. Mar and Dz induced biochemical effects on the serotonergic metabolism, which can alter the development and function in rat brain, because it has also been involved in scavenging free radicals present there.

Effect of sibutramine on Na+, K+ ATPase activity and tryptophan levels on male and female rat brain.

Some drugs that are clinically used in weight control, like sibutramine, act on the serotonergic metabolism, but its relation with free radical (FR) production in the CNS is still unknown. The aim of the work was to evaluate the effect of sibutramine on FR production. Female and male Wistar rats (250 g weight) were used; the animals received sibutramine (10 mg/kg each 36 hours) intraperitoneally during 15 days. At the end of the study, the rats were sacrificed and their brains used to measure lipid peroxidation (TBARS), Na+, K+ ATPase activity, reduced glutathione (GSH), and tryptophan (TRP) levels, by means of validated methods. The activity of Na+, K+ATPase and total ATPase was increased in males and decreased in females. GSH concentration was increased and the levels of TBARS decreased by an effect related to sibutramine in the female group. Sibutramine decreased TRP concentration in the female group, but increased it in the male one, with respect to the control group. Our results suggest that sibutramine produce an antioxidant effect stimulated by the endogenously produced tryptophan and it protects the fluidity of plasma membrane in rat brain.

[Hepatic anatomophatologic injuries by extrahepatic biliar tract obstruction in mice]. / Lesiones anatomopatológicas hepáticas por la obstrucción de la vía biliar extrahepática en ratones.

UNLABELLED: The aim is to evaluate the liver damage due to an experimental animal model based in the temporal obstruction of biliar extrahepatic duct and determine the relation between obstruction and severity of damage through time. METHODS: We used 20 adults male mice going from 25 to 35 g weight, previous to general anesthesia, a surgical incision was applied and biliar duct were localized and tied using linen cloth. Six animals were sacrificed each time at 1, 7 and 15 days of treatment, the hepatic, lung, kidney, hearth and brain were obtained for histopatologic analysis using optic microscope. RESULTS: In the first day 20% of hepatic samples, light lesions as sinusoidal congestion and dilation of portal vessel with hepatocelular biliar stasis were found. In 7th day additional lesions were found as accumulations of biliar pigments in the cholangiols, proliferation of portal collagens and light pericholangiolar proliferation in 60% of samples. At 15th day, severely lesions as hamartomatous proliferation of cholangiols and portal fibrosis of biliar ducts that deformed the boundary plaque and lobular in 15% of samples. In brain, hearth, and lung samples showed vascular dilation and severe congestion, except at 15th day, when samples of kidneys showed biliar pigment precipitation in lumen of collets ducts. CONCLUSIONS: The proposed method is useful to study the chronologic relationship of anatomophatologic damage produced by biliar obstruction.

Changes in the survival of patients with systemic lupus erythematosus in childhood: 30 years experience in Chile.

The objective of this study was to analyse the survival rate and cause of death in children with systemic lupus erythematosus (SLE) during the past 30 years in Chile. A retrospective analysis was performed between 1969 and 2000 on patients attending pediatric rheumatology centres in Santiago, Chile. Survival and causes of death in 31 children followed from 1969 to 1980 fulfilling the 1982 American College of Rheumatology criteria for SLE and treated with oral steroids were compared with 50 other patients who were treated with oral steroids and an aggressive treatment of IV bolus of cyclophosphamide (38 patients) and azathioprine (12 patients). Global survival at five and 10 years follow-up for the patients studied from 1969 to 1980 was 68 and 40%, respectively. During the second study period these values were significantly improved and global survival reached 95% at five years and 90% at 10 years follow-up (P < 0.05). Survival at 10 years follow-up for patients with lupus nephropathy increased from 28% (study period 1964-1980) to 86% (study period 1984-2000). Twelve children died (38%) during the 1964-1980 study period. The causes of death were six due to kidney failure, three due to infectious conditions and another three of unknown causes. During the 1980-2000 study period mortality reached 6% (three cases), two cases died of a lupus flare-up and one case due to infection. In the last three decades, we have seen an important increase in the survival of children with SLE, especially in those patients with renal involvement. Management with immunosuppressive drugs, such as IV cyclophosphamide or azathioprine has changed the prognosis in these children. These results demonstrate that our children with SLE increased their life expectancy but are now faced with new types of morbidity because of the sequelae related to the disease itself.

Bioavailability of ranitidine in healthy Mexican volunteers: effect of food.

Is well known that food can affect the bioavailability of several drugs, its impact is major for those drugs that have to act near of drug absorption. Documentation about alterations of ranitidine bioavailability by effect of food is poor. The purpose of this work was to evaluate the effect of food over the bioavailability of ranitidine. Twenty healthy Mexican volunteers were included for the study. The study was made in two stages, in the first one the volunteers had 12 hour fast and took a 300 mg of oral dose of ranitidine (without food, WOF) and blood samples were drawn. Two weeks later, the volunteers took a normal diet just before ranitidine intake (with food, WF). The area under the curve (AUC) was 30% greater in WOF, Cmax was 921.5 ng/ml (WF) vs. 1685.2 (WOF), and t1/2 was 2.70 +/- 1.38 (WF) h vs 3.66 +/- 1.34 (WOF). The AUC, Cmax and t1/2 were statistically different. It is evident that there are differences in the drug disposition due to the presence of food, then, it is possible that the efficacy of ranitidine as inhibitor of gastric secretion being limited by food.

Patterns of drug consumption in relation with the pathologies of elderly Mexican subjects resident in nursing homes.

PURPOSE: To describe the patterns of drugs consumed by the male and female elderly living in Mexican private and public nursing homes. METHODS: Three hundred and fifty elderly participants from four nursing homes (2 private and 2 public) were selected for the six month study: 108 subjects were excluded; the remaining 242 were between 65 and 100 years old; 123 were females and 119 males. A complete clinical history was taken and clinical files were reviewed. RESULTS: Of the 242 elderly studied, 193 took diverse medications and 28.5% were at risk of some type of drug interaction. The groups of drugs more frequently consumed were vitamins and anti-anemic medications, followed by cardiovascular drugs. Females consumed greater number of drugs. They also consumed more drugs simultaneously. CONCLUSIONS: There is a need to monitor the elderly for their drugs pattern use.

Expression and localization of proteoglycans during limb myogenic activation.

After arriving at the limb bud, migrating myogenic precursor cells express transcription factors responsible for the induction of terminal skeletal muscle differentiation. One such factor is myogenin, a member of the basic helix-loop-helix family, known to activate the expression of muscle-specific genes. The extracellular signals involved in activating the myogenic program in the muscle precursor cells that reach the limb in vivo are not known. However, in vitro, it has been shown that proteoglycans, macromolecules composed of a core protein and glycosaminoglycan chains, modulate the triggering of myogenin activity. To understand the role of proteoglycans during limb muscle development, we assessed the synthesis of proteoglycans in limb bud explants at 10.5 days post coitum, when migrating cells arrive, evaluated the expression and nature of these macromolecules during in vivo early limb bud formation, and determined the colocalization of myoblasts expressing myogenin with specific proteoglycans. We found that the expression of myogenin was temporally and spatially coincident with the expression of syndecan-3 and decorin, two essential proteoglycans in the modulation of skeletal muscle differentiation. This article is the first report of myogenic activation and proteoglycan expression during limb muscle formation.