Tests of chronic and acute toxicity of crude oil on larvae of Chironomus kiiensis Tokunaga (Diptera: Chironomidae) / Teste de toxicidade aguda e crônica de óleo cru em larvas de Chironomus kiiensis Tokunaga (Diptera: Chironomidae)

The Amazon region, known for its mega-biodiversity, also holds large reserves of petroleum and natural gas. The increasing exploitation of natural gas and crude oil in the Amazon has not been accompanied by studies evaluating the impact of these pollutants on local biological communities, particularly aquatic organisms. The aim of the present study was to determine the values of acute and chronic toxicity of crude oil from Urucu to larvae of Chironomus kiiensis Tokunaga, 1936. The LD5048h of crude oil for second-instar larvae of C. kiiensis was 26.5 mg/L, and mortality for the majority of concentrations tested was greatest during the first 24 hours of the experiment. The survival of eggs of C. kiiensis exposed to concentrations of crude oil was also evaluated but did not differ significantly among the treatments. Despite the high tolerance observed for the species in the experiments, there is a possibility that in the natural environment the oil interacts with other factors, leading to synergistic effects, so further studies are needed to assess the effects of this pollutant on aquatic insect species.

A região Amazônica, conhecida por sua megabiodiversidade, também é detentora de grandes reservas de petróleo e gás natural. A crescente exploração de gás natural e óleo cru na Amazônia não é acompanhada de estudos avaliando o impacto destes poluentes nas comunidades biológicas locais, especialmente organismos aquáticos. Neste trabalho, o objetivo das autoras foi determinar os valores de toxicidade aguda e crônica de óleo cru proveniente de Urucu para larvas da espécie Chironomus kiiensis Tokunaga, 1936. A CL5048h de óleo cru para larvas de segundo instar de C. kiiensis foi de 26,5 mg/L e a mortalidade para a maioria das concentrações testadas foi maior durante as 24 primeiras horas do experimento. A sobrevivência dos ovos de C. kiiensis expostos a concentrações de óleo cru também foi avaliada, porém sem diferença significativa entre os tratamentos. Apesar da alta tolerância da espécie observada nos experimentos, em ambiente natural existe a possibilidade do óleo interagir com outros fatores, apresentando efeito sinérgico, e mais estudos avaliando o efeitos deste poluente sobre insetos aquáticos são necessários.

Tests of chronic and acute toxicity of crude oil on larvae of Chironomus kiiensis Tokunaga (Diptera: Chironomidae).

The Amazon region, known for its mega-biodiversity, also holds large reserves of petroleum and natural gas. The increasing exploitation of natural gas and crude oil in the Amazon has not been accompanied by studies evaluating the impact of these pollutants on local biological communities, particularly aquatic organisms. The aim of the present study was to determine the values of acute and chronic toxicity of crude oil from Urucu to larvae of Chironomus kiiensis Tokunaga, 1936. The LD5048h of crude oil for second-instar larvae of C. kiiensis was 26.5 mg/L, and mortality for the majority of concentrations tested was greatest during the first 24 hours of the experiment. The survival of eggs of C. kiiensis exposed to concentrations of crude oil was also evaluated but did not differ significantly among the treatments. Despite the high tolerance observed for the species in the experiments, there is a possibility that in the natural environment the oil interacts with other factors, leading to synergistic effects, so further studies are needed to assess the effects of this pollutant on aquatic insect species.

Effects of an oil spill and discharge of domestic sewage on the insect fauna of Cururu stream, Manaus, AM, Brazil.

Assemblages of aquatic and edaphic insects in three streams in Central Amazonia were used to evaluate the impact on one of the streams (Cururu) caused by an oil spill that occurred in August 1999. The Cururu stream had already been impacted by domestic sewage. These three streams were evaluated during four different periods of the regional hydrological cycle (falling-, low-, rising- and high-water), from September 2000 to May 2001. An Eckman dredge, an aquatic entomological net and a manual auger were used to collect insects, which were used to estimate the taxonomic richness (at the family level) and insect density in each stream. Anoxic and eutrophic conditions were determined in each stream based on the mean concentration of dissolved oxygen, total nitrogen and phosphorus. Richness and abundance of insect fauna were higher in the Cristalino stream (not impacted) than in the Bom Jardim stream (impacted by domestic sewage) and in the Cururu stream, with the exception of samples collected along the stream banks (littoral fauna). The mean dissolved oxygen was lower in the Cururu stream than in the other two, while the mean concentrations of total nitrogen and phosphorus were higher. These elements showed intermediate values in the Bom Jardim stream, while the opposite pattern was observed in the Cristalino stream, with higher concentrations of dissolved oxygen and lower concentrations of total nitrogen and phosphorus. The concentrations of these variables reflect the modifications resulting from anthropogenic eutrophication caused by the discharge of domestic sewage into Bom Jardim and Cururu and by the oil spill in Cururu, which negatively affected the richness and abundance of insects in these streams.

Effects of an oil spill and discharge of domestic sewage on the insect fauna of Cururu stream, Manaus, AM, Brazil

As assembléias de insetos aquáticos e edáficos de três igarapés da Amazônia Central foram utilizadas para avaliar o impacto sofrido por um deles (igarapé Cururu), após um vazamento de óleo derivado de petróleo, ocorrido em agosto de 1999. O igarapé Cururu já era impactado pelo despejo de esgoto doméstico. A avaliação desses sistemas foi realizada em quatro diferentes períodos do ciclo hidrológico da região (vazante, seca, enchente e cheia), entre setembro de 2000 e maio de 2001. Os insetos foram coletados com draga Eckman, rede entomológica aquática e trado, e utilizados para estimar a riqueza taxonômica (nível de família) e a densidade de insetos em cada sistema. Os efeitos de anóxia e os efeitos da eutroficação foram mensurados pelas médias de concentração de oxigênio dissolvido, nitrogênio total e fósforo total, estimadas nos três sistemas. A riqueza e abundância da fauna de insetos foram maiores no igarapé Cristalino (não impactado) do que nos igarapés Bom Jardim (impactado pelo despejo de esgoto) e Cururu, com exceção das amostragens de insetos litorâneos. A concentração do oxigênio dissolvido no igarapé Cururu foi menor do que nos outros dois sistemas, enquanto as concentrações de nitrogênio total e fósforo total no igarapé Cururu foram maiores. Esses elementos tiveram valores inversos no igarapé Cristalino e intermediários no igarapé Bom Jardim. As concentrações de oxigênio dissolvido, nitrogênio total e fósforo total refletem as modificações provocadas pela eutroficação antropogênica nos sistemas Bom Jardim e Cururu. Isso ocorreu devido à liberação de efluentes domésticos pelas comunidades locais e pelo óleo introduzido no igarapé Cururu, influenciando negativamente a riqueza e abundância de insetos nesses igarapés.

Toremifene-induced fatty liver and NASH in breast cancer patients with breast-conservation treatment.

We have described fatty liver, diagnosed by computed tomography scanning (CT) in more than 30% of patients with breast cancer who received tamoxifen. Therefore, it is urgent to elucidate the frequency and the degree of fatty liver induced by toremifene, an analogue of tamoxifen, which is also used in breast cancer. We enrolled 52 breast cancer patients who were treated with breast-conservation treatment and administered oral toremifene for 3-5 years as adjuvant endocrine therapy. We evaluated the degree of fatty liver by abdominal CT performed annually. CT demonstrated toremifene-induced fatty liver in four (7.7%) of 52 breast cancer patients. Toremifene-induced fatty liver did not correlate with abnormal levels of AST, ALT, GGT or total cholesterol. One patient who demonstrated moderate fatty liver by CT was histologically diagnosed as non-alcoholic steatohepatitis (NASH) by liver biopsy. The incidence of toremifene-induced fatty liver was significantly lower than that induced by tamoxifen. Accordingly, in terms of fatty liver and NASH, toremifene is considered to be more appropriate agent than tamoxifen. Though toremifene is less likely to induce fatty liver, the possibility remains that toremifene-induced steatohepatitis occurs. Because the diagnosis of fatty liver or NASH can be easily missed if only a blood test is performed, it is necessary to screen fatty liver by annual CT examination for patients who receive an antiestrogen agent.

[Intraoperative hemodilutional autotransfusion using a closed circuit for patients of Jehovah's Witness].

We conducted hemodilutional autotransfusion using a closed circuit combined with a cell washing reinfusing system (Cell Saver) for two surgical patients of Jehovah's Witness. One was a 12 yr-old boy for extirpation of the teratoma in the anterior mediastinum and another was a 44 yr-old woman for left total hip replacement. The patients and their relatives had consented to the use of blood substitutes, hemodilutional autotransfusion using a closed circuit and Cell Saver. We devised a closed circuit system for hemodilutional autotransfusion combined with Cell Saver, in which two pumps for blood transfusion were used; one was for drawing blood from the femoral or the internal jugular vein and the other for returning blood to the peripheral vein. Blood volume in a bag interposed in the closed circuit was easily controlled by adjusting the speed of each pump. Blood collected from the surgical field by Cell Saver was also led to the bag. Acid citrate dextrose solution was infused into the closed circuit from the site close to the blood drawing. Both of our surgical patients were safely managed without homologus blood transfusion, although there remained some problems concerning the use of anticoagulants.

Glutamine metabolism of intestine grafts: influence of mucosal injury by prolonged preservation and transplantation.

The demand for glutamine increased only in the preserved intestine in the early postoperative period (3 days after transplantation). Glutamine demand of the preserved grafts returned to control and immediate levels 7 and 14 days after transplantation. Three days after intestinal transplantation, when the intestinal mucosa was actively regenerating, the demand for glutamine was markedly enhanced. The enhanced demand for glutamine was met by increased output of glutamine by the liver and skeletal muscle. Glutamine uptake by the intestinal graft was enhanced by a brief infusion of glutamine. Thus, we believe exogenous glutamine supplementation may be beneficial for the recovery of intestinal grafts with severe mucosal injury.

Early experiences of breast-conservation treatment combined with tamoxifen and CAF chemotherapy for breast cancer of stages I and II.

A total of 39 patients with breast cancer of stages I and II received breast-conservation treatment (BCT) combined with tamoxifen and systemic chemotherapy (CAF) from August 1989 to March 1993. All of these patients visited the outpatient clinic of the Department of Radiology of Kochi Medical School Hospital, with an obvious desire to undertake BCT. During this period, another two patients with the same desire were treated with modified radical mastectomy, because of obviously positive surgical margins in frozen sections obtained at surgery. The percentage of patients treated by BCT was, therefore, 95.1%. All of the patients were females, and their average age was 49.9 years. Thirty-six of these 39 patients underwent lumpectomy, and another three patients with large-sized tumor or suspected extensive intraductal component underwent quadrantectomy or wide local excision. Nineteen of these 39 patients who were over 70 years old or had no clinically detectable axillary lymph node swelling received tangential field radiotherapy to their ipsilateral axillary region instead of axillary dissection. At the end of May 1993, the mean follow-up time was 22.4 months. Until now, one patient (T2N1M0, stage IIB) has died of distant metastases of breast cancer to bone, liver, lung, and brain, and another patient, aged 81, died of pneumonia with no evidence of breast cancer progression. The overall survival rates were, therefore, 100% (30/30), 90.0% (18/20), and 75.0% (6/8) at 1 year, 2 years, and 3 years, respectively. Cause-specific survival rates were 100% (30/30), 94.7% (18/19), and 85.7% (6/7) at 1, 2, and 3 years, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum parathyroid hormone concentration measured by highly sensitive assay in post-thyroidectomy hypocalcemia of patients with Graves' disease.

To investigate the role of parathyroid function in transient hypocalcemia after subtotal thyroidectomy for Graves' disease, the serum parathyroid hormone (PTH) concentration and nephrogenous (N) cAMP were measured in 16 patients before and after surgery. Serum PTH was measured with two commercially available kits (PTH-M, PTH-C), PTH-M is a recently developed highly sensitive assay using an antibody recognizing the mid-portion of human PTH and a synthetic 125I-tyr45-human PTH (43-68) as a radioligand. One of the 16 patients had severe clinical tetany and had a markedly lower PTH-M concentration and NcAMP after thyroidectomy. However, no significant change in serum PTH-M, PTH-C and NcAMP were observed in the other patients, although their serum calcium (Ca) concentrations decreased significantly. The Data were analyzed by dividing the patients according to the change in serum Ca or PTH. Serum PTH-M and PTH-C significantly decreased in 4 patients whose serum Ca clearly decreased after surgery. Serum Ca on the first postoperative day was significantly lower in patients whose serum PTH decreased after thyroidectomy than in patients whose serum PTH did not. Furthermore, the serum Ca concentration was significantly correlated with PTH-M, and with NcAMP on the third postoperative day. These data proved that hypofunction of the parathyroid gland is important in transient hypocalcemia after subtotal thyroidectomy for Graves' disease. The pathogenetic mechanism of transient hypocalcemia was discussed in comparison with the data from a patient who had overt parathyroid injury.

Depression of delayed-type hypersensitivity in mice with hypothalamic lesion induced by monosodium glutamate: involvement of neuroendocrine system in immunomodulation.

Delayed-type hypersensitivity (DTH) was depressed in mice that had been treated with monosodium glutamate (MSG) in their suckling period. Analysis of the DTH depression by use of the macrophage migration inhibition assay showed dysfunction of DTH effector T cells. The neuronal loss of nuclei in the hypothalamus, which elaborates the corticotropin-releasing factor and the hypersecretion of adrenocorticotrophic hormone, was observed in the MSG-treated mice. Therefore, DTH response may be modulated by the neuroendocrine system.