RESUMEN

The value of aflatoxins is well known as a carcinogenic, mutagenic and teratogenic, likewise its association with the hepatitis B virus. In addition, it is known the incidence of hepatocellular carcinoma in such viral infection. A study was performed on the albumin adducts-aflatoxins levels in sera determined by ELISA method of children within 3-15 years old at the Service of Pediatric Gastroenterology from the National Institute of Gastroenterology. Samples consisted of 40 patients with chronic active hepatitis (CAH) B, 10 HBsAg+ carriers and 20 controls. The CAH group, showed a 32.5% of positiveness with a maximum levels of 25pg aflatoxin lysine/mg albumin while 20% of HBsAg positive carriers showed levels of un 12.3 pg aflatoxin lysine/mg albumin and 15% of the control group 5pg AF lysine/mg albumin. It can be observed that aflatoxin levels in patients of CAH presented values up to 5 times over the control group. This study suggest the validity of aflatoxin-albumin adducts as a marker of chronic exposure to this carcinogen and its importance in relation with the virus of hepatitis B.

Asunto(s)

RESUMEN

Durante la última década una serie de investigaciones epidemiológicas y de laboratorio han demostrado una fuerte asociación entre el virus de la hepatitis B, la exposición a aflatoxina en la dieta y el incremento de la incidencia del carcinoma hepatocelular. En el instituto de oncología se desarrolló y validó el método inmunoenzimático para la detección de aflatoxina en orina. Se estudiaron 54 niños con un rango de edad (4-16) de la consulta de gastroenterologia, 30 con diagnóstico de hepatitis crónica activa (HCA) AgsHB+ resultando positivos el 56

Asunto(s)

RESUMEN

During the last decade, a number of epidemiological and laboratory investigations have shown a close association among hepatitis B, dietary exposure to aflatoxin, and an increased incidence of hepatocellular carcinoma. An immunoenzymatic method for aflatoxin detection in urine was developed and assessed at the National Institute of Oncology. Fifty four children (age range 4-16 years) from the pediatric service at the National Institute of Gastroenterology were studied. Thirty patients had a diagnosis of chronic active hepatitis (CHA 17 of which 56%) were found aflatoxin- positive, 20 where HbsAg-positive carriers of which 7 of 35% were positive to aflatoxin, and 4 patients suffered from metabolic diseases from which 1 (25%) was found aflatoxin- positive. Controls and patients were matched by age, with 7.5% of aflatoxin-positive patients. Our results confirm the link between hepatitis B and aflatoxin in this type of patients compared to controls. The immunoenzymatic system proved to be specific for aflatoxin detection with a sensitivity of 100 picograms/milliliter.

Asunto(s)

Asunto(s)

RESUMEN

The presence of mycotic flora in atmospheric medium has always been an interesting field for allergologists and ecologists interested in the problems of environmental contamination. In 1904 Saito in Japan demonstrated that certain spores of fungus when inhaled by susceptible individuals can produce severe respiratory processes. Since then many studies have been performed to determine the generic and species of causative fungus responsible for respiratory allergy, as well to understand its growth, movement and seasonal variations and its relation with the habits of man. Fungi which may produce allergy were investigated in 6 zones of the south of Mexico City, from November, 1981 to October, 1982. In each zone 108 samples were taken. Petri dishes containing Sabouraud medium were exposed during 10 minutes. The number of colonies per Petri dish; 27.6 per cent of the micro-organisms isolated corresponded to allergy producing fungi. The highest frequency of fungal isolation (6,512 colonies) was obtained in summer and the least (1,397 colonies) during winter. The principal genera isolated were: Rhodotorula: 2,418 (16.7%); Phialophora: 2,071 (14.4%); Penicillium: 743 (5.1%); Alternaria: 111 (0.7%). The most frequent species of the Aspergillus were: A. niger, A. fumigatus and A. flavus. The paper discusses the importance of the different factors which can influence the frequency and the seasonal variations of these fungi.

Asunto(s)

Asunto(s)

RESUMEN

Hemagglutination inhibiting antibodies were studied in 1,278 sera of individuals of different ages in Mexico City representative of four different socioeconomic levels. It was found that 1,261 (98.7 per cent) had antibodies against the Nebraska strain (calf rotavirus). An unusual finding was that more than 95 per cent of children from one to four years of age, had antibodies. For this reason five year old children were studied utilizing two viral strains as antigens in hemagglutination inhibition tests. It was found that in 918 sera, 821 (89.4 per cent) had antibodies against SA-11 samples (monkey rotavirus); percentage increased from 87.2 per cent in neonates to 97.5 percent in children from four to five years of age. A similar phenomenon was observed when Nebraska strain hemagglutinin was utilized. Also complement fixation antibodies against SA-11 strain in 583 sera were studied finding that 260 (44.6 per cent) had antibodies. Utilization of this technique showed that seropositivity percentage decreased from 47.6 per cent in the neonate group to 14.5 per cent in the one ot three month old children increasing progressively until reaching 65.1 per cent in children three to four years of age. These results show that rotavirus infection takes place at early ages, as has been confirmed by other authors that have used electron microscopy techniques, RNA electrophoresis, etc., regardless of the presence of transplacental antibodies.

Asunto(s)

RESUMEN

Rotavirus was investigated in the feces of 232 children under five years of age with acute infectious gastroenteritis by means of viral RNA electrophoretic technique. 15.1 per cent of cases were positive and no predominance was observed regarding age or seasonal period. Approximately 50 per cent corresponded to one of the two rotavirus types, byt type 2 (2 L) was predominant in the first six months of the year and type 1 (2 S) in the other six. Results are consistent with those obtained by other authors for it is considered that approximately 20 per cent of acute diarrheas during infancy are caused by viral agents.

Asunto(s)

Asunto(s)

RESUMEN

Se estudio la presencia de rotavirus en la materia fecal de 232 ninos menores de cinco anos con gastroenteritis infecciosa aguda por medio de la tecnica de electroforesis del RNA viral. Se encontraron 15.1 por ciento de casos positivos, no observandose predominio en relacion con la edad o la epoca del ano.Aproximadamente 50 por ciento correspondieron a cada uno de los dos tipos de rotavirus, pero el tipo 2 (2 L) predomino en los seis primeros meses del ano y el tipo 1 (2 S) en los otros seis. Los resultados concuerdan con los obtenidos por otros autores, ya que se considera que aproximadamente 20 por ciento de las diarreas agudas de la infancia son causadas por estos agentes virales

Asunto(s)

Asunto(s)

RESUMEN

A longitudinal study was carried out in 40 patients with typhoid fever, 21 with infectious hepatitis and 15 with amebic liver abscess in order to determine percentual values of lymphocytes T and B in relation with age and nutritional state as compared to a normal control group. In patients with typhoid fever, a decrease of percentual values of lymphocytes T was observed starting on the second week of evolution with intensification on the third week, predominating in patients less than seven years of age and in malnourished cases (p less than 0.001) and late recovery in the group of patients less than seven years old. In patients with acute infectious hepatitis, there was depression of lymphocytes T that persisted to the eighth week and was independent of age, but more severe in the malnourished (p less than 0.001). In cases with amebic liver abscess, depression of lymphocytes T was observed during the first six weeks of evolution without relation with age or the state of nutrition, but with increased slowliness in recovery in patients under seven years. There were no disturbances in lymphocytes B nor in cutaneous response to dinitrofluorobencene (DNFB) in the three groups of patients.

Asunto(s)

RESUMEN

Diphenylhydantoin (DFH) treatment for epileptic patients has shown adverse effects such as malignant lymphadenopathy, systemic lupus erithematosus, periarteritis nodosa and recently immunological alterations such as a decreased lymphocytic response to fitohemaglutinin and serum IgA concentration, therefore we thought DFH effect on secretory IgA would be an important finding. This phenomenon might imply a defect in resistance local mechanisms for infection. Two groups of patients were studied: a) 25 children with an established diagnosis of epilepsy, "grand mal" type, that received anticonvulsive treatment with DFH for six months and b) 25 children with a diagnosis of infectious meningoencephalitis that required DFH to control convulsive crisis. Patients with a history of recurrent infections, lymphadenopathies, hepatosplenomegaly, drug allergy, collagenopathies and immunodeficiency were ruled out from this study. In all patients T and B lymphocytes, serum IgA, saliva and duodenal fluid and IgA determinations were made. Results show IgA concentration decrease in saliva and duodenal fluid of epileptic and meningoencephalitic patients (p less than 0.05), as well as lymphocyte T depression in epileptic and non epileptic patients treated with DFH (p less than 0.001).

Asunto(s)

RESUMEN

Zinc effects on phagocytic activity depend upon its serum concentration. According to certain experimental findings, a decrease in zinc serum concentration is parallel to a deficiency in host defense mechanisms and thus we were interested in studying the effect of zinc sulphate in the phagocytic function of polymorphonuclear cells of 15 zinc deficient patients with III degree malnourishment. In all patients, zinc serum determinations were made before and after zinc intake and chemotaxis, phagocytosis and NBT reduction tests were made at 7, 14 and 30 days. Results are compared with an eight patient group with similar clinical and nutritional characteristics observing an improvement in PMN cell phagocytic activity in patients with zinc uptake (p < 0.001). No differences were observed in a chemotaxic phagocytosis and NBT reduction tests in regard to the time during which patients did not receive zinc uptake.

Asunto(s)

RESUMEN

The presence of antigen of D. pneumoniae and H. influenzae was detected by counter-immunoelectrophoresis (CIE) in 113 LCR of children with central nervous system (CNS) infection (17 viral, 70 bacterial and 6 tuberculous). From 41 normal children spinal fluid was obtained and used as control. Precipitation band was not observed in normal children cases of viral and tuberculosis meningitis. In 21 cases of bacterial meningitis, D. pneumoniae and H. influenzae was isolated in six cases each. In six cases of bacterial meningitis were positive both bacteriological study and CIE. In 49 cases in which culture was negative only 13 gave positive CIE. When other strains of bacteria were isolated, no positive band was detected with CIE. This technic was regarded as useful for detecting etiologic agent in purulent meningitis.

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)