Natural radioactivity in groundwater and estimates of committed effective dose due to water ingestion in the state of Chihuahua (Mexico).

The activity concentration of 222Rn, 226Ra and total uranium in groundwater samples collected from wells distributed throughout the state of Chihuahua has been measured. The values obtained of total uranium activity concentration in groundwater throughout the state run from <0.03 up to 1.34 Bq l-1. Generally, radium activity concentration was <0.16 Bq l-1, with some exceptions; in spring water of San Diego de Alcalá, in contrast, the value reached approximately 5.3 Bq l-1. Radon activity concentration obtained throughout the state was from 1.0 to 39.8 Bq l-1. A linear correlation between uranium and radon dissolved in groundwater of individual wells was observed near Chihuahua City. Committed effective dose estimates for reference individuals were performed, with results as high as 134 microSv for infants in Aldama city. In Aldama and Chihuahua cities the average and many individual wells showed activity concentration values of uranium exceeding the Mexican norm of drinking water quality.

Uranium-238 and thorium-232 series concentrations in soil, radon-222 indoor and drinking water concentrations and dose assessment in the city of Aldama, Chihuahua, Mexico.

High-resolution gamma spectrometry was used to determine the concentration of 40K, 238U and 232Th series in soil samples taken from areas surrounding the city of Aldama, in Chihuahua. Results of indoor air short-time sampling, with diffusion barrier charcoal detectors, revealed relatively high indoor radon levels, ranging from 29 to 422 Bq/m3; the radon concentrations detected exceeded 148 Bq/m3 in 76% of the homes tested. Additionally, liquid scintillation counting showed concentrations of radon in drinking water ranging from 4.3 to 42 kBq/m3. The high activity of 238U in soil found in some places may be a result of the uranium milling process performed 20 years ago in the area. High radon concentrations indoor and in water may be explained by assuming the presence of uranium-bearing rocks underneath of the city, similar to a felsic dike located near Aldama. The estimated annual effective dose of gamma radiation from the soil and radon inhalation was 3.83 mSv.

Neutropenia febril de alto riesgo en leucemia aguda. Experiencia en un hospital público. Programa Nacional de Drogas Antineoplásicas del Adulto (PANDA), Hospital del Salvador, 1991-2001 / High risk febrile neutropenia in acute leukemia. The experience of a public hospital. National Program of Antineoplastic Drugs in Adult, Hospital del Salvador, 1991-2001

BACKGROUND: Febrile neutropenia is one of the most important problems to face during the treatment of acute leukemia. AIM: To assess the results of a standardized protocol for the treatment of febrile neutropenia and compare it with a period in which treatment was not standardized. PATIENTS AND METHODS: One hundred and eight episodes of febrile neutropenia in 69 patients, treated with a standardized antimicrobial protocol between 1996 and 2001, were analyzed. The protocol consisted in the use of a combination of antimicrobial whose spectrum was broadened progressively according to the isolated microorganisms and the involved foci. These were compared with 83 episodes in 54 patients, treated without standardized protocols between 1990 and 1995. RESULTS: Both groups of patients were comparable. Their ages ranged from 15 to 65 years old. The male/female ratio was 1.3 and the lymphoblastic/myeloid leukemia ratio was 1.4. Sixty one percent of episodes occurred during induction chemotherapy and mean duration of neutropenia was 17 days. A clinically significant focus was identified in 72 per cent of episodes and a microorganism was isolated blood culture in 35 per cent of them. There was a predominance of gram negative organisms. The mortality decreased from 18 to 9 per cent in the period 1996-2000 (p = 0.094). CONCLUSIONS: The use of a standardized antimicrobial protocol reduced the mortality in febrile neutropenia, even when colony stimulating factors and filtered air rooms are unavailable.

[Acute myeloid leukemia in the adult. Results of the National Antineoplastic Drug Protocol at the Hospital del Salvador, 1990-1998]. / Leucemia mieloide aguda del adulto. Resultados del Protocolo Nacional de Drogas Antineoplásica. Hospital del Salvador 1990-1998.

BACKGROUND: The incidence of acute myeloid leukemia is 3 cases per 100,000 inhabitants/year and its five years event free survival is 15 to 20%. Since the incorporation of trans retinoic acid, event free survival of M3 acute myeloid leukemia is 80%. AIM: To report the results of acute myeloid leukemia treatment at the Hospital del Salvador, between 1990 and 1998. PATIENTS AND METHODS: The medical records of 117 patients (66 female, mean age 48.2 years), treated between 1990 and 1998 using PANDA protocol, were retrospectively reviewed. Immunophenotyping was done in 69 patients and cytogenetic studies were done in 65. RESULTS: Sixteen percent of patients had M3 acute myeloid leukemia. The most frequent phenotype was the association of DR, CD34 plus a panmyeloid marker. DR and CD34 were negative in seven of nine patients with M3 acute myeloid leukemia. Cariotype was abnormal in 78% of patients. Complete remission was achieved in 65% of cases with a 13% of failures. Early mortality was 21.3% and decreased to 6.1% in the last three years. Infections and coagulation disorders were the main causes of death. Mean survival was 10.5 months. Five years event free survival was 11%. In M3 acute myeloid leukemia, the figure is 50%. CONCLUSIONS: Treatment results are less effective than protocols that consider more aggressive chemotherapeutic protocols or bone marrow transplantation. The reduction in early mortality is due to a better management of febrile neutropenia.

HTLV-I positive progressive spastic paraparesis (TSP) associated with a lymphoid disorder in three Chilean patients.

We describe the clinical and laboratory features in three Caucasian Chilean patients with tropical spastic paraparesis (TSP) associated with/or preceded by a lymphoproliferative disorder involving cutaneous lesions and localised lymphadenopathy. The neurological symptoms and signs were characteristic of TSP and CSF examination revealed the presence of oligoclonal bands. All three patients had a moderate leucocytosis (10-14 x 10(9)/l) with eosinophilia and a minority (2-4%) of circulating atypical polylobed or ATLL-like lymphocytes. Lymph node histology showed a diffuse pattern of infiltration (1 case) and marked expansion of the paracortical zone with convoluted lymphocytes and immunoblasts (2 cases). Skin biopsy demonstrated a dermal lymphoid infiltration with epidermotropism. Antibodies to HTLV-I were detected in the serum and CSF in the three patients and Southern blot analysis of peripheral blood mononuclear cells showed a monoclonal integration of HTLV-I proviral DNA in one case whereas in the two others the pattern was indicative of low level polyclonal integration. All three patients were treated with prednisolone and one with PUVA with transient partial response on the skin and neurological manifestations. Two patients died months to 5 years from presentation and the other is alive 12 years from diagnosis with active neurological and skin disease. The simultaneous occurrence of HTLV-I associated TSP with smouldering ATLL and a cutaneous ATLL or pre-leukaemic form is discussed.