HLA-B*5701 frequency in Chilean HIV-infected patients and in general population

It has been demonstrated that HLA-B*5701 screening reduces the risk for hypersensitivity reaction to abacavir in HIV-infected patients. Since B*5701 prevalence varies among different populations, it is important to determine the carrier frequency prior to its use for the screening of HIV-infected patients.The aim of this study was to determine HLA-B*5701 carrier frequency in Chilean general population and HIV-infected patients referred for B*5701 typing. For that purpose 300 blood bank donors and 492 abacavir-naïve HIV-infected patients from Chile were screened for B*5701 by a sequence specific primer PCR.We detected 14/300 (4.7 percent) B*57-positive individuals in the Chilean general population, 11 (3.7 percent) were B*5701 positive, and 3 (1 percent) had another subtype.All were heterozygous,thus a B*5701 allele frequency of 2 percent was determined.Eleven of 492 (2.2 percent) HIV-patients carried a B*5701 allele. The difference between these frequencies is probably due to slow progression of HIV infection in HLA-B*5701 carriers, thus less patients would require antiretroviral therapy and B*5701 typing. Considering the usefulness of B*5701 screening, its prevalence in the Chilean general population,and the availability of a validated method,we conclude that HLA-B*5701 typing in Chilean HIV-infected patients about to initiate abacavir treatment is strongly recommended.

Aviso de valores de alerta por parte del laboratorio clínico en una red de salud universitaria / Laboratory alert value reporting by the clinical laboratory at an academic medical network

Background: An alert value is a result suggesting that the patient is at imminent danger unless appropriate remedial actions begin promptly. Report of alert values (AV) by the clinical laboratories has taken special relevance in recent years due to its contribution to patient's care. Aim: To report results of AV informed during 2007 within the Health Network of the Pontificia Universidad Católica de Chile. Material and methods: Analysis of AV recorded in a centralized database of the laboratories of the health network, between January and December, 2007. Results: Total number of AV was 5.366, which represented 0.3 percent of total examinations and corresponded mainly to the clinical chemistry area. Potassium levels generated the higher number of AV detected, followed by positive blood cultures. Eighty two percent of AV corresponded to hospitalized patients. The greater number of AV was reported to intermediate and intensive care services. Thirty two percent of AV was informed to the physician or professional in charge of the patient within 5 minutes of obtaining the results and 79 percent within 30 minutes. Conclusions: To obtain a real impact on patient management, it is fundamental to shorten the ¡apse between the obtainment of tests results and the warning, supported on appropriate computerized systems, and to spread the procedure to all personnel involved in patient's care (RevMéd Chile 2009; 137: 1137-44).

Presencia de macroprolactina en sueros con normo e hiperprolactinemia: comparación de dos métodos de detección / Comparison of two techniques to detect the presence of macroprolactin in serum

Background: Macroprolactin is biologically inactive but may be detected by immnoassays. This leads to errors in diagnosis and inadequate treatment of patients with hyperprolactinemia. Aim:To assess two techniques to detect the presence of macroprolactin. Material and Methods: Prolactin was measured by immunoassay in 57 serum samples (from 4 males and 53 females aged33 +/- 13 years), before and after precipitation with polyethyleneglycol (PEG) and separation by ultrafiltration. A significant level of macroprolactin was considered to be present when prolactin detected in the supernatant after PEG precipitation or in the ultrafiltrate was less than 40 percent of the initial concentration of prolactin. Results: Prolactin levels fluctuated from 5 to 411 ng/ml. The percentages of recuperation were independent of the initial prolactin concentration. In 12 and 14 percent of samples, using polyethyleneglycol and ultrafiltration respectively, there was a prolactin recuperation of less than 40 percent. Eight and 11 percent of samples with a prolactin concentration of more than 30 ng/ml, had a recuperation of less than 40 percent using polyethyleneglycol and ultrafiltration respectively. Conclusions: Approximately 10 percent of samples with a prolactin concentration over 30ng/ml have recuperation values suggestive of the presence of macroprolactin. There is a good concordance between precipitation using polyethyleneglycol or ultrafiltration.

Comparación de distintos métodos para evaluar la función androgénica en el adulto mayor / Assessment of androgenic decline in the elderly

Background:The gold standard to assess androgenic status is the measurement of free testosterone by equilibrium dialysis. However, the estimation of free testosterone using formulas based on the law of mass action can be an adequate standard. Aim: To assess androgenic decline in the elderly by different methods. Material and methods: Free testosterone by radioimmunoassay, total testosterone and steroid binding globulin (SHBG) by automated chemiluminiscence system and estradiol by automated electrochemiluminiscence system were measured in 30 male aged 64±5 years (range 60-70), and 25 males aged between 20 and 30 years, as control group; devoid of diseases or drugs that could cause hypogonadism. Free androgen index, free testosterone, biavailable testosterone, and free estradiol were calculated using a formula based on the law of mass action. Results: Fifty seven percent of elderly subjects had hypogonadism, according to calculated free testosterone values. Their total testosterone was on average, 152 nd/dl lower than in young adults, figure that represents a 3.8 ng/dl decline per year. According to total testosterone values, 27 percent of elderly males had gonadal incompetence. The correlations between calculated free testosterone and total testosterone was 0,95 and between calculated free testosterone and measured free testosterone was 0,67. The methods employed overestimated (76.7 percent of hypogonadism when using the free androgen index) or underestimated (27 and 3 percent of hypogonadism, considering total or free testosterone, respectively) the ondrogen decline of the elderly. Among the elderly, 16 or 30 percent of subjects had an absolute hypoestrogenism, based on estradiol or calculated free estradiol values, respectively. On average there was a 20 and 30 percent reduction of estradiol and calculated free estradiol values in the elderly. Conclusions: Calculated free or bioavailable testosterone values should be used to assess androgen decline in elderly men.

Estudio comparativo de dos equipos de glicemia capilar / Comparative study of 2 devices for capilary blood glucose measurement

En el presente estudio se probaron los equipos Super glucocard II y b-Glucose analyzer para glicemia capilar en una población adulta (n=70) y se compararon los resultados con el método tradicional del laboratorio (hexoquinasa realizado en el equipo Hitachi 917tm). Se evaluó la precisión y linearidad, los efectos del hematocrito y del ácido ascórbico. Se utilizaron los métodos estadísticos de regresión lineal simple, la prueba t de Student con una significancia de p<0,05 y la comparación de métodos por Bland-altman. Los resultados fueron evaluados bajo los criterios de la National Committee for Clinical Laboratory standards (NCCLS) para equipos de glicemia capilar. Los resultados demostraron una correlación de 0.952 y 0,975 respectivamente, encontrándose diferencias significativas entre glicemias de los equipos y del método de referencias (p<0,01). Ningún valor mayor de 100 mg/dl estuvo fuera del rango de concordancia aceptado para glicemias capilares, según los criterios de la NCCLS. El coeficiente de variación fue menor de 6 por ciento en los dos equipos, para distintos niveles de glicemia. Ambos presentaron exelente linearidad entre 50 y 400 mg/dl y se demostró que el nivel de hematocrito puede influir en las determinaciones. El ácido ascórbico demostró ser un interferente en ambos equipos

Velocidad de disolución de diferentes preparados de calcio utilizados en clínica / Dissolution velocity of different calcium solutions used in clinics

Hydrochloric acid was added to destilled water in increasing amounts to obtain a final pH of 6.9, 3.0, 2.5, 2.0 and 1.5. Eighteen commercial calcium preparations were incubated in these solutions for 60 min and dissolution velocity was measured as the percentage of elemental calcium found in solution after this incubation period. Calcium carbonate preparations had a pH 1.5. Using the solution with pH 1.5 the dissolution velocity of different preparations varied widely from 56 to 100 percent. Calcium acetate, followed by calcium citrate and dicalcic phosphate were the salts in tablets with better dissolution velocities. Among powders and effervescent preparations, those containing calcium lactogluconate and citrate had the better dissolution velocities (95 to 115 percent), that were independent of the solution's pH. A studied preparation with integral bone had a very low dissolution velocity, not surpassing 33 mg of calcium per tablet. The dissolution velocity of different calcium carbonate preparations varies greatly and in conditions of achlorhydria, it is negligible. Calcium lactogluconate and citrate dissolution velocities are independent of the solution's pH

Frecuencia y características de la masturbación en adolescentes femeninas / Frecuence and characteristics of masturbation in female adolescents

Con el objetivo de conocer las características y establecer la frecuencia de la masturbación en adolescentes femeninas de tres (3) Liceos públicos de la ciudad de Santo Domingo, realizamos un estudio prospectivo longitudinal con 601 estudiantes del sexo femenino de 13-19 años de edad. La frecuencia masturbatorio osciló en un 77.3 (por ciento), que excede de la relación genital heterosexual (26 por ciento) y homosexual (17.3 pro ciento) coincidiendo su mayor pico a los 16-17 años de edad. Se destacan los porcentajes de las que se masturban para liberal tensiones emocionales, las que no logran orgasmo y las que tienen sentimientos de culpa y verguenza

Evaluación inmunológica e inmunogenética de pacientes con cáncer de la vesícula biliar: comunicación preliminar / Immunologic and immunogenetic evaluation of the patients with gallbladder cancer: preliminary comunication

Se estudiaron cinco pacientes con cáncer de la vesícula biliar (CV) con prolongada sobrevida postoperatoria (4-12 años): Grupo A. Se compara este grupo con cinco pacientes intervenidos recientemente, cuya enfermedad está avanzada: Grupo B y con cinco enfermos sometidos a colecistectomía por litiasis y sin cáncer: Grupo C (control). En el Grupo A hubo 2 casos con antecedentes de cáncer en otras localizaciones (mama, útero y recto), lo que hace suponer una predisposición neoplásica y una especial inmunidad contra el cáncer. En este estudio preliminar, la respuesta inmunitaria de los pacientes del Grupo A y C fue similar. En los enfermos del Grupo B, se observó reducción de la inmunocompetencia con la progresión de la enfermedad, especialmente en los test cutáneos. En el estudio histoquímico, en los Grupos A y B, las poblaciones celulares relacionadas con la inmunidad se situaron en la periferia del tumor pero sólo en las del Grupo A se encontraron en el interior de la masa tumoral. En la investigación inmunogénetica se observó que el antígeno HLA-DR4 se encuentra en una proporción mayor en los pacientes con CV (38%), en comparación con la población chilena nornal (29%). Se incluye que es necesario: a. Proseguir la investigación, aumentando el número de casos; b. trabajar en el estudio inmuno histoquímico sólo con vesículas frescas, y c. Seguir investigando los antígenos del sistema HLA, tanto en pacientes portadores de cáncer vesícular, como en aquéllos con simple colelitiasis

Eficacia de la lincomicina en el tratamiento de la amigdalitis aguda / Efficacy of lincomicyn in the treatment of acute amigdalitis

Se estudiaron 48 pacientes con cuadro clínico de faringo-amigdalitis pultácea. Sólo en 32 pacientes se aisló Streptococcus beta-hemolítico Grupo A. Sin embargo a todos los pacientes estudiados y posterior a la toma de cultivo y exámenes de sangre, se les trató con lincomicina 1 gr. por vía intramuscular y luego 500 mgrs. cada 8 horas por vía oral hasta completar 10 días. Se usó lincomicina ya que ha demostrado ser un agente efectivo contra el Streptococcus beta hemolítico Grupo A, la concentración en el tejido amigdaliano llega a niveles que van de 9,52 mcg/gr. hasta 23,26 mcg/gr. y tiene gran afinidad para penetrar al núcleo de la amígdala y erradicar tanto a las bacterias anaeróbicas como a los Staphylococcus productores de beta-lactamasa, motivo de su mayor efectividad. La sensibilidad de las cepas se determinó por técnicas de Concentración Inhibitoria Mínima (CIM); y los antibióticos probados fueron: penicilina, meticilina, ampicilina, cefalotina, eritromicina, lincomicina y vancomicina. El resultado de la terapia fue excelente, no se manifestaron reacciones adversas, sólo en un paciente se presentó diarrea al décimo día de tratamiento, no siendo necesaria la suspensión de la terapia

Factibilidad del transplante renal de donante cadáver pediátrico a receptor adulto / Feasibility of renal transplantation from cadaver donor to adult patient

Se presentan 2 pacientes adultos con insuficiencia renal crónica terminal en quienes se realizó un transplante renal con riñones en bloc de donantes cadáver pediátrico. Los resultados en nuestros casos, junto con los escasos casos comunicados en la literatura, demuestran su utilidad. Dado el insuificiente número de riñones disponibles para transplante, debemos utilizarlos de la forma más eficiente posible