Mediobasal hypothalamic and adenohypophyseal TRH-degrading enzyme (PPII) is down-regulated by zinc deficiency.

Thyrotropin-releasing hormone (TRH) synthesized in hypothalamic paraventricular nucleus directs hypothalamus-pituitary-thyroid (HPT) axis function, regulating thyrotropin release from adenohypophysis and thyroid hormones serum concentration. Pyroglutamyl aminopeptidase II (PPII), a Zn-dependent metallopeptidase located in adenohypophysis and medial-basal-hypothalamus degrades TRH released from the median eminence and participates in HPT axis function by regulating TRH-induced thyrotropin release from adenohypophysis. It is unknown whether dietary Zn deficiency down-regulates PPII. Our aim was to compare adenohypohyseal and medial-basal-hypothalamic PPII activity and expression of adult rats fed a Zn-deficient diet (2ppm) throughout their lifespan (DD), prenatally (DC) or after weaning (CD) vs. that of animals fed a control diet (20ppm:CC). Female rats consumed a Zn-deficient or control diet from two weeks before gestation and up to the end of lactation. We analyzed adenohypophyseal and medial-basal-hypothalamic PPII activity of dams and male offspring when adults; its relation to median eminence TRH, serum thyrotropin, leptin and thyroid hormones concentration. Offspring ate the same diet as their dams (CC, DD) or were switched from dietary regime after weaning (CD, DC) and until 2.5 months of age. DD males showed decreased adenohypophyseal and medial-basal-hypothalamic PPII activity, along with high thyrotropin serum concentration. Post-weaning Zn-deficiency (CD) decreased PPII activity only in adenohypophysis and increased thyrotropin circulating levels. Zn-replenishment (DC) normalized PPII activity in both regions and serum thyrotropin concentration. Adenohypophyseal PPII activity decreased and prolactin levels increased in Zn-deficient dams. We concluded that long-term changes in dietary Zn down-regulate PPII activity independently of T3, increasing thyrotropin serum concentration, overall resembling sub-clinical hypothyroidism.

[Desensitization protocol to methotrexate. Clinical case]. / Protocolo de desensibilización a metotrexato. Caso clinico

Methotrexate (MTX) is a folic acid antagonist; its main effects are immunosuppressive and antineoplastic. It is used in the treatment of malignancies, lung and rheumatic diseases. There are few reports of immediate hypersensitivity and these include anaphylaxis, urticaria and angioedema. We present a 17 years old male, with a history of anaphylaxis to methotrexate during the induction therapy of ALL L2. It was decided that the drug was necessary for the patientís survival, thus diagnostic skin testing was performed, during which he presented anaphylaxis. The desensitization consisted of 5 days premedication and a 12-steps protocol of intravenous infusions of 8 hoursí duration, starting with a 1:1.000.000 dilution. The patient was successfully desensitized. He was maintained with IV MTX 50mg/m2 weekly for 1 year using the same protocol successfully. This protocol of 12 steps was successful and safe to desensitize a patient with anaphylaxis due to MTX. During such protocol intensive care supervision is critical, as all precautions should be taken to avoid endangering the life of the patient.

The systemic inhibition of nitric oxide production rapidly regulates TRH mRNA concentration in the paraventricular nucleus of the hypothalamus and serum TSH concentration. Studies in control and cold-stressed rats.

Neurons of the paraventricular nuclei of the hypothalamus (PVN) that synthesize the peptide thyrotropin releasing hormone (TRH) control energy homeostasis. Identifying the circuits which regulate these neurons is critical to fully understand integration of metabolic information and the mechanisms that set thyroid hormone levels. We tested the hypothesis that nitric oxide (NO) acutely controls PVN TRH expression and thyrotropin (TSH) secretion by the anterior pituitary. The subcutaneous treatment of rats with N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthases, enhanced PVN TRH mRNA and medio-basal hypothalamic TRH levels, and reduced serum TSH concentration. Analysis of the effect of a NO donor in primary cultures of hypothalamic or anterior pituitary cells suggested that the effect of NO includes a direct action on hypothalamic neurons. The cold stress-induced increase in TSH release was inhibited by sc L-NAME. Therefore, production of NO may control the activity of the hypothalamus-pituitary-thyroid axis.

Effect of divalent cations on the porcine kidney cortex membrane-bound form of dipeptidyl peptidase IV.

Dipeptidyl peptidase IV is an ectopeptidase with multiple physiological roles including the degradation of incretins, and a target of therapies for type 2 diabetes mellitus. Divalent cations can inhibit its activity, but there has been little effort to understand how they act. The intact membrane-bound form of porcine kidney dipeptidyl peptidase IV was purified by a simple and fast procedure. The purified enzyme hydrolyzed Gly-Pro-p-nitroanilide with an average V(max) of 1.397±0.003 µmol min(-1) mL(-1), k(cat) of 145.0±1.2 s(-1), K(M) of 0.138±0.005 mM and k(cat)/K(M) of 1050 mM(-1) s(-1). The enzyme was inhibited by bacitracin, tosyl-L-lysine chloromethyl ketone, and by the dipeptidyl peptidase IV family inhibitor L-threo-Ile-thiazolidide (K(i) 70 nM). The enzyme was inhibited by the divalent ions Ca(2+), Co(2+), Cd(2+), Hg(2+) and Zn(2+), following kinetic mechanisms of mixed inhibition, with K(i) values of 2.04×10(-1), 2.28×10(-2), 4.21×10(-4), 8.00×10(-5) and 2.95×10(-5) M, respectively. According to bioinformatic tools, Ca(2+) ions preferentially bound to the ß-propeller domain of the porcine enzyme, while Zn(2+) ions to the α-ß hydrolase domain; the binding sites were strikingly conserved in the human enzyme and other homologues. The functional characterization indicates that porcine and human homologues have very similar functional properties. Knowledge about the mechanisms of action of divalent cations may facilitate the design of new inhibitors.

Carboplatin hypersensitivity and desensitization in an infant.

Although the reported incidence of carboplatin hypersensitivity is low, it is important to describe it because of its potentially fatal consequences. A 1-year-old Mexican girl weighing 10 kg who had optic nerve glioma was initially scheduled to receive 12 cycles of 600 mg/m2 carboplatin (CBP) as two 300-mg/m2 intravenous infusions administered over 1 hour on 2 different days and a 1-hour intravenous infusion of 1.5 mg/m2 vincristine every 4 weeks. The patient had no history of drug allergies or any type of adverse drug reaction, but she developed itchiness, maculopapular rash, sweating, respiratory distress, and anxiety during the seventh cycle of CBP. According to the algorithm developed by Naranjo et al, the adverse drug reaction was classified as definite secondary to CBP and confirmed by positive skin tests indicating hypersensitivity to the drug. After evaluating the clinical course of the adverse drug reaction and considering the need to continue cancer treatment, a decision was made to desensitize the patient to CBP. The desensitization procedure took 8 hours and was performed during each new chemotherapy cycle until the 12 cycles of chemotherapy were successfully completed. In summary, a case of CBP hypersensitivity in a 1-year-old girl who was successfully desensitized to CBP is reported.

NMDA receptor up-regulates pyroglutamyl peptidase II activity in the rat hippocampus.

Ecto-peptidases hydrolyze peptides in the extracellular fluid of the brain. This process is critical for defining the strength of peptidergic communication. A few studies suggest that brain ecto-peptidase activities are regulated by brain function but the extracellular messengers involved are generally unknown. Pyroglutamyl peptidase II (PPII) is specific for thyrotropin releasing hormone (TRH), a tripeptide with multiple homeostatic functions in brain. The purpose of this study was to identify regulators of brain PPII activity. Electrical stimulation (multiple tetani) did not change PPII activity in cortical or hippocampal slices. However, in hippocampal slices, blockade of calcium channels with high magnesium, or of L-type calcium channels (LTCC) or NMDA receptors, decreased PPII activity, while blockade of AMPA or GABA(A) receptors did not. Blockade of NMDA receptors did not change PPII mRNA levels but decreased PPII levels. The activity of another ecto-peptidase, aminopeptidase N, was also down regulated by a magnesium blockade, not regulated by NMDA receptor blockade and increased by LTCC blockade. The data show a differential regulation of the activity of ecto-peptidases by that of Ca(2+) channel and that synaptic activity, through the NMDA receptor, specifically regulates that of pyroglutamyl peptidase II.

Anterior pituitary pyroglutamyl peptidase II activity controls TRH-induced prolactin release.

Ecto-peptidases modulate the action of peptides in the extracellular space. The relationship between peptide receptor and ecto-peptidase localization, and the physiological role of peptidases is poorly understood. Current evidence suggests that pyroglutamyl peptidase II (PPII) inactivates neuronally released thyrotropin-releasing hormone (TRH). The impact of PPII localization in the anterior pituitary on the endocrine activities of TRH is unknown. We have studied whether PPII influences TRH signaling in anterior pituitary cells in primary culture. In situ hybridization (ISH) experiments showed that PPII mRNA was expressed only in 5-6% of cells. ISH for PPII mRNA combined with immunocytochemistry for prolactin, beta-thyrotropin, or growth hormone, showed that 66% of PPII mRNA expressing cells are lactotrophs, 34% somatotrophs while none are thyrotrophs. PPII activity was reduced using a specific phosphorothioate antisense oligodeoxynucleotide or inhibitors. Compared with mock or scrambled oligodeoxynucleotide-treated controls, knock-down of PPII expression by antisense targeting increased TRH-induced release of prolactin, but not of thyrotropin. Similar data were obtained with either a transition-state or a tight binding inhibitor. These results demonstrate that PPII expression in lactotrophs coincides with its ability to control prolactin release. It may play a specialized role in TRH signaling in the anterior pituitary. Anterior pituitary ecto-peptidases may fulfill unique functions associated with their restricted cell-specific expression.

Participation of Rho, ROCK-2, and GAP activities during actin microfilament rearrangements in Entamoeba histolytica induced by fibronectin signaling.

In Entamoeba histolytica little is known about the microfilament rearrangements formed by actin and ABPs. Fibronectin regulates many aspects of cell behavior involving the actin cytoskeleton and members of the Rho family of small GTPases. Using trophozoites interacted with fibronectin and glass, we present evidence related with the formation and regulation of different microfilament rearrangements and their cellular distribution, the effect of actin affecting drugs on these arrangements, and on trophozoites adhesion; we also demonstrate that actin isoforms are induced after adhesion, and also the selective participation of specific actin binding proteins such as ABP-120 and phospho-paxillin, regarding their location in the different actin structures. In addition, we show results that confirm the participation of EhRho, ROCK-2, and GAP activities. We propose that fibronectin induced signaling in E. histolytica trophozoites have important consequences in the actin cytoskeleton that may affect its behavior during the invasive process in the host.

[Uncommon manifestations of atopic dermatitis]. / Manifestaciones poco frecuentes de dermatitis atópica.

Atopic dermatitis is an inflammatory process characterized by a series of cutaneous alterations of typical morphology and distribution, with intense pruritus of nocturnal predominance, of chronic evolution, stational appearance, and with personal and family history of atopy. On genetically predisposed skin, dry and hypersensitive, the immune factors and other types are implicated in determining the abnormal reactions to multiple endogenous and environmental factors. The diagnosis is clinical, generally obtained by a group of signs and symptoms known as the Hanifin and Rajka criteria. The patients with atopic dermatitis can present with clinical typical manifestations, or minimized and localized variations as well, considered a stigma of atopic constituent. In some patients there can be observed clinical and morphological variations with special localizations denominated atypical variations of atopic dermatitis. The identification of these atypical presentations of atopic dermatitis leads to the differential diagnosis, with an early establishment of the disease's diagnosis and the appropriate and early treatment.

[Allergic conjunctivitis in children]. / Conjuntivitis alérgica en la infancia.

Allergic conjunctivitis is a group of diseases that are frequent in childhood, associated to several allergic diseases affecting the ocular surface. It is related to type 1 hypersensitivity reactions. Two acute disorders: seasonal allergic conjunctivitis and perennial allergic conjunctivitis, exist, as do three chronic diseases: vernal keratoconjunctivitis, atopic keratoconjunctivitis and giant papillary conjunctivitis. The ocular surface inflammation causes itching, tearing, lid and conjunctival edema-redness, and photophobia during the acute phase and can lead to a classic late-phase response (associated to eosinophilia and neutrophilia) in a subset of individuals. As in the case of several chronic allergic diseases, it can remodel the ocular surface tissue. This allergic disease is very frequent. Vernal keratoconjunctivitis could produce corneal lesions and visual illness; however, atopic keratoconjunctivitis does not permanently affect the vision. The aim of this review is to provide a current overview for a better understanding of the symptoms associated to this disease, to describe its classification, recent advances in its physiopathology and its treatment.

Asthma prevalence in children living in north Mexico City and a comparison with other Latin American cities and world regions.

Reports of previous studies done without following the international guidelines in different cities of Mexico showed a decrease in asthma prevalence. The aim of this study was to determine the prevalence and severity of asthma symptoms in children and teenagers living in north Mexico City and compare them with those of other Latin American cities and world regions. The cross-sectional survey followed the protocol of the International Study of Asthma and Allergies in Childhood IIIb phase survey. The study population included children 6-7 years old and teenagers 13-14 years old from randomly selected primary and secondary schools. There were 1629 boys and 1582 girls in the group of 6- to 7-year-old children and 2039 boys and 1860 girls in the 13- to 14-year-old group. "Wheezing or whistling in the chest at any time in the past" was present in 19.2% (95% confidence interval [CI], 17.9, 20.6) of the children and in 17.0% (95% CI, 15.8, 18.1) of the teenagers; "wheezing or whistling in the chest in the last 12 months" was reported in 6.8% (95% CI, 5.9, 7.6) of the children and 9.9% (95% CI, 9.0, 10.8) of the teenagers; "asthma ever" was claimed in 4.5% (95% CI, 3.8, 5.2) of the children and 8.0% (95% CI, 7.1, 8.8) of the teenagers. These prevalences were low compared with other ISAAC Latin American surveys and intermediate in comparison with worldwide regional prevalences reported by ISAAC surveys. The prevalence of asthma is low in Mexico City in comparison with other surveyed locations, but the number of patients with asthma makes it an important issue for Mexican public health programs.

Plan de ordenamiento predial (POP) de la comunidad de Kirusillani

Elaborar participativamente un Plan de Ordenamiento Predial en la comunidad de Kirusillani, con la finalidad de identificar acciones orientadas al manejo sostenible de los Recursos Naturales existentes (agua, tierra y vegetación). La metodología se divide en tres fases que son: 1. Preparación y establecimiento de bases 2. Recopilación y análisis de la información y digitalización de mapas. 3. Validación-evaluación y entrega del POP. Los resultados obtenidos son: una memoria técnica descriptiva del POP que incluye información de unidades de tierra, uso actual de la tierra, uso potencial concertado o POP y priorización de acciones a corto, mediano y largo plazo. El POP al ser un instrumento de fácil manejo y comprensión para la comunidad, se constituye en un instrumento de planificación participativa adecuado para normar e implementar acciones orientadas al manejo y aprovechamiento sostenible de los recursos naturales y debe ser actualizado periódicamente

[Quality of life in children with allergic rhinitis before and after being treated with specific immunotherapy (cases and controls)]. / Calidad de vida en niños con rinitis alérgica antes y después de ser tratados con inmunoterapia específica (casos y controles).

BACKGROUND: Rhinitis is the most frequent allergic disease in children. Symptoms may affect importantly life quality. Measures to avoid allergens when possible and the use of drugs are an important part of the treatment; however, specific immunotherapy is the only treatment altering the natural course of the disease. OBJECTIVE: To assess if specific immunotherapy improves life quality in children with allergic rhinitis. MATERIAL AND METHODS: Patients who attended to the allergy department during August and September 2002, and who fulfilled the inclusion criteria, were included. Two groups of treatment were formed: group A received specific immunotherapy with standardized allergenic extracts, from IPI ASAC Mexico. They started with a concentration of 0.07 bioequivalent units (BEU), with twice-a-week-application with increases of 10 (0.7, 7 and 80 BEU) each seven weeks up to maintenance dose of 700 BEU at six months. Group B only was given pharmacological treatment. Paediatric Rhinoconjunctivitis Quality of Life Questionnaires, specific to children with allergic rhinoconjunctivitis, validated for its use in Spanish in Mexican children by the department of Clinical Epidemiology and Biostatistics of Mc Master University, were applied to all patients. RESULTS: Twenty-seven patients were included in each group, 14 males, adjusted for age with a correlation coefficient (r2) = 0.9799. In both groups, mean age was of 11 years 6 months (group A: 7 to 16 years, group B: 7 to 17 years). Eighteen (44.4%) and fifteen patients (33.3%), of groups A and B respectively, had persistent mild rhinitis, and 9 (55.6%) and 12 cases (66.7%) of groups A and B, respectively, had moderate persistent rhinitis. All of them were sensitized to domiciliary allergens. As to life quality a high odds ratio (OR) was found when assessing patients six months after treatment, especially in nasal symptoms such as pruritus (OR = 6.8) and obstruction (OR = 5.9). Also for practical symptoms the OR was high: carving eyes and nose (OR = 7), blowing the nose (OR = 4.8) and carrying disposable tissues (OR = 4.7). OR for other symptoms was as follows: thirst and throatitch, OR = 4; irritability, OR = 6.2, and ocular pruritus, OR = 3.1. Patients without immunotherapy were likely to use more drugs (OR = 6.4) than those receiving immunotherapy. CONCLUSION: We did not find controlled studies on life quality with the use of immunotherapy in children. In this study, specific immunotherapy was found to improve life quality in children with allergic rhinoconjunctivitis, especially in nasal symptoms, such as pruritus and obstruction, as well as in practical symptoms. These results are similar to those by Fell, who found that 92% patients referred an improvement of nasal symptoms, a better labor performance and a lesser use of drugs after four months of using immunotherapy.

[Calisthenics as a preventive measure against the decrease in maximum expiratory flow in asthmatic patients before and after a soccer game]. / Calistenia como medida preventiva de la caída del flujo espiratorio máximo en pacientes asmáticos antes y después de un juego de futbol.

BACKGROUND: Exercise-induced asthma is a syndrome characterized by dyspnea, thoracic pain, cough, sibilant rales and diminished physical performance. It appears into the first 30 minutes after the beginning of physical activity. OBJECTIVE: To evaluate calisthenic effect on maximal expiratory flow rate in asthmatic patients. MATERIAL AND METHODS: A prospective, observational and descriptive study was done through a soccer game. Male and female asthmatic patients from 6 to 16 years old with intermittent and mild asthma were included. Maximal expiratory flow rate was measured before the beginning of soccer game, and then, at the end of the first and second sets. Statistical analysis was made through the media values comparison and t Student test. RESULTS: 60 patients were included. They were 11.3 +/- 2.4 mean aged. 45% had diagnosis of mild asthma, 36.6% mild asthma and allergic rhinitis and 6.6% persistent asthma. Average of basal maximal expiratory flow rate was 275 +/- 90 L/s, and no significant changes were observed in 52 patients: mean maximal expiratory flow rate at the end of first and second sets was 275 +/- 86 L/s and 273 +/- 96 L/s, respectively. Maximal expiratory flow rate diminished at 77 +/- 3.8% and 83 +/- 9.5% in the other eight patients at the end of the first and second sets, respectively. CONCLUSIONS: Calisthenic made before physical activity prevents maximal expiratory flow rate diminishment.

[The response to PPD and its relation to allergic diseases in children vaccinated at birth with BCG]. / La respuesta al PPD y su relación con las enfermedades alérgicas en los niños vacunados al nacimiento con BCG.

BACKGROUND: The increase of the atopical disorders can be partially explained by two factors, the infectious disease in developed and developing countries, and the changes in immunization programs, infections such as measles, whooping cough or tuberculosis can modify the immune response. Recent studies have demonstrated that an inverse relation could exist between the response to late cutaneus hypersensitivity to Mycobacterium tuberculosis and atopic condition. Also, a strong positive response has been associated with low levels of IgE and Th1 cytokines. However some authors have not found positivity between low prevalence in allergic diseases and PPD. OBJECTIVE: To determine the reaction to PPD in children vaccinated with BCG at birth and its disorders. MATERIAL AND METHOD: The study sample included male and female children from 2 to 7 years old, vaccinated with BCG at birth, this fact was corroborated with the post vaccination scar. They had all been diagnosed with allergic disease with clinical compatible data, positive Prick test, elevated serum IgE, and absence of any associated immune deficiency. RESULTS: A total of 50 patients, with a mean age of 4.7 years (2.0 to 7.7 years) were studied. 72% (36) were males and 28% (14) females. Twenty-two percent had diagnosis of asthma, 8% allergic rhinitis, and 62% both diagnosis. The average diameter of tuberculin induration was of 5 mm; 5 patients (10%) had positive reaction (+10 mm); 23 patients (46%) were between 5-9 mm; 8 patients (16%) between 1-4 mm, and 14 of the patients (28%) without reactivity. CONCLUSION: We demonstrated that the vaccination with BCG do not protect against the development of allergy, and the negative tuberculin response may mean a reduced cell response. So, it is necessary to assess the cell immunity and revaccination with BCG, with determination of immunological markers, before and after, such as IL 4, IL 2, INF and allergy symptoms.

[Allergen sensitization and asthma in children from 1 to 3 years of age]. / Sensibilización con alergenos y asma en niños de uno a tres años de edad.

BACKGROUND: Asthma is a multifactorial disease. Children with atopy history could be sensitized with indoor and food allergens from early stages of the life and this predispose to develop asthma. Controversy exists about the factors that increase or decrease the risk of disease, such as breast feeding, early weaning, smoking exposition, immunizations. OBJECTIVE: To determine if these risk factors and inhaled and food allergen sensitization predispose to asthma development. METHODS: A case-control study was performed. Cases (1 to 3 year-old 74 children) with asthma and control (74 healthy age-matched children) were included, r2 = 0.90. Skin-prick test (SPT) was performed by using indoor and food allergens. Test was considered positive if skin reaction was equal or higher than 3 mm. The results were compared by means of the x2 test. A logistic regression analysis was performed for obtaining odds ratio (OR) (95% confidence interval for each factor). RESULTS: Out of the SPT carried out with aero-allergens, 23 (31%) were positive in the two groups. Regarding the food, 27 cases (36.4%) and 15 controls (20.2%) were positive (x2 = 4.7); p < 0.05, OR = 2.2, IC 95% (1.6-3.1). Atopy was positive in 50 (67.5%) cases and 39 (52.7%) of the controls (x2 = 3.4); p < 0.05, OR 1.8 (1.3 to 2.5). The weaning before the first three months of life was positive in 44 (59.4%) of the cases against 15 (20.2%) of the controls (x2 = 23.7) p < 0.05 with a OR 5.7 (4.9 at 6.6). CONCLUSIONS: We found a probability 2.2 times higher for developing asthma when children were sensitive to at least one food. We also reported that 100% of our sensitized cases with food had received breast feeding during the first four months of life, which is similar to results of other authors where the breast feeding during an intermediate time (one to six months) does not protect against allergic disease. Early introduction of solid food (before the three months of age) was the main factor increasing probability for developing asthma. In our study, atopy almost duplicated this probability.

Síndrome de hiper IgE y deficiencia de IgG1 e IgM / Hyper-IgE syndrome associated with IgG1 and IgM deficiency

Introducción. El síndrome de hiperinmunoglobulina E (hiper IgE) es una inmunodeficiencia congénita autosómica dominante con penetrancia incompleta, caracterizada por dermatitis crónica grave, infecciones frecuentes, formación de abscesos, valores séricos de IgE elevados (>2000 UI/mL) y eosinofilia periférica. Se puede asociar con múltiples alteraciones de la respuesta inmune. Se presenta el caso de un paciente con la rara asociación no reportada de hiper IgE y deficiencia de IgG1. Caso clínico. Masculino de 6 años de edad con dermatosis crónica, infecciones de vías aéreas de repetición, presencia de abscesos fríos en miembros inferiores, con mala respuesta a antihistamínicos, queratolíticos y lubricantes. Por mala evolución clínica y sospecha de inmunodeficiencia fue enviado al Hospital Infantil de México Federico Gómez. A su ingreso presentaba dermatosis generalizada activa y sinusitis maxilar bilateral, manejándose con cefaclor, antihistamínicos, y cuidados de piel. Un mes después se complicó con varicela por lo que se hospitalizó, quedando con cicatrices queloides. Se le diagnosticó hiper IgE por evolución clínica y niveles de IgE de 11 000 UI/mL, asociado con deficiencia de IgG1 y niveles persistentemente subnormales de IgM. Se le inició tratamiento con trimetoprim y sulfametoxazol a 5 mg/kg/día durante 3 meses con buena respuesta clínica; posteriormente presentó remisión de su enfermedad. Conclusión. Se encontró el síndrome de hiper IgE asociado a una deficiencia de IgG1 que lo hace más susceptible a infecciones por diferentes patógenos y niveles subnormales de IgM.

Efecto temprano y tardío de la prueba cutánea con Blatella germanica (Bg) y/o Periplaneta americana (Pa) sobre el volumen espiratorio forzado y el flujo espiratorio máximo en niños con alergia respiratoria / Early and late effect of the skin prick test with cockroach (Blatella germanica and/or periplaneta american) on the forced expiratory volume and peak expiration flow in children with respiratory allergy

Introducción. Se ha demostrado que los alergenos de cucaracha sensibilizan a los niños atópicos y frecuentemente predisponen al desarrollo de asma grave a temprana edad. Objetivo: evaluar los cambios tempranos como tardíos sobre el volumen espiratorio forzado (VEF1) y flujo espiratorio máximo (FEM) en niños con alergia respiratoria y prueba cutánea (PC) positiva a antígeno de cucaracha.Material y métodos. Estudio prospectivo longitudinal cruzado doble ciego controlado en niños de 6 a 16 años de edad con un VEF1 y FEM basal mayor de 80 por ciento de su predicho y PC positiva exclusivamente a Blattella germanica (Bg) y/o Periplaneta americana (Pa). En diferentes momentos se midió el VEF1 y FEM antes de la PC con Ba y/o Pa, o con placebo (solución glicerinada) y se realizaron espirometrías y flujimetrías a los 15 min 2, 4, 6, 8, 12, 24 y 48 horas. Análisis estadístico: se utilizó t de Student para muestras pareadas.Resultados. Se estudiaron 30 pacientes con PC positiva a alergeno de cucaracha: 21 hombres y 9 mujeres; 20 presentaron PC positiva a Bg y Pa, 8 a Bg y 2 a Pa. Catorce de 30 pacientes presentaron caída del VEF1 a los 15 min, 13 de ellos la presentaron también a las 6, 12 y 24 horas después de la PC con antígeno. Sólo 3 pacientes presentaron esa caída a los 15 min de la prueba con placebo. En todas las mediciones del grupo estudiado con alergeno de cucaracha se encontró caída del VEF1 mayor de 15 por ciento (P=0.02). En el FEM no se encontró diferencia estadística significativa en ninguno de los grupos (P=0.5).Conclusiones. La medición del VEF1 fue más eficaz para detectar caídas, tanto tempranas como tardías. Por el contrario el FEM no fue sensible para detectar cambios en la función pulmonar después de reto cutáneo con alergenos de cucaracha.

Determinacion de caudales de crecida para la cuenca del Rio Morochata mediante le modelo hidrologico HEC-HMS / sss

En el presente trabajo se hizo la estimacion de caudales de crecida para la Cuenca de Morochata, para los periodos de retorno de 5, 15, y 25 años. Los resultados obtenidos son los siguientes: por el metodo de SCS una descarga total de 94.8mm, 143.1mm, y 280.8mm, para los periodos de retorno de 5, 15, 25 años respectivamente. Por el metodo de Snyder una descarga total de 93.5mm, 141.2mm, y 278.5mm, para los periodos de retorno de 5, 15, y 25 años respectivamente...

Efecto del calentamiento sobre el VEF-1 en niños con asma sometidos a reto por ejercicio / The effect of a heating routine in children with asthma

Antecedentes: el broncoespasmo inducido por ejercicio, también llamado asma por ejercicio, es una afección frecuente que acompaña comúnmente al paciente asmático. Su frecuencia es de alrededor del 80 al 90 por ciento para los pacientes con asma; se presenta en 40 al 50 por ciento de los niños con rinitis alérgica, en 14 por ciento de los atletas y en 12 por ciento de la población en general. Objetivo: determinar la eficacia de una rutina de calentamiento como agente preventivo del broncoespasmo inducido por ejercicio. Método: se incluyeron 30 pacientes de entre 10 y 16 años de edad, asmáticos y con broncoespasmo inducido por ejercicio diagnosticado mediante prueba de reto al ejercicio. Todos los pacientes realizaron una rutina de ejercicio con duración de 20 minutos durante los cuales se efectuaron movimientos de elasticidad, calistenia y actividad leve dirigida al ejercicio a desarrollar, tomando como parámetro objetivo el 60 por ciento de la frecuencia cardiaca submáxima. Enseguida, todos los pacientes realizaron nuevamente reto al ejercicio, en la que se utilizó una banda sinfín, con velocidades que se incrementaron progresivamente de 1 a 8 km/h y con inclinación de 0 - 10 0. Los registros espirométricos se efectuaron antes del reto y a los 2, 5, 10, 15, 20, 25, 30 y 60 minutos después del mismo. Resultados: el promedio de edad de los pacientes fue de 12.8 ñ 2 años con talla de 157 ñ 10 cm. Conclusión: el calentamiento en niños con broncoespasmo inducido por ejercicio actúa como un agente protector contra el decremento del VEF-1. Si bien el calentamiento puede ser un buen método de control en el paciente asmático, es necesario tener en cuenta que no todos los pacientes tienen un beneficio con dicha protección.Éste sólo puede utilizarse en pacientes con actividad física programada, ya que en los preescolares no es posible implantar una rutina de calentamiento por las características propias de su actividad.