In vivo implants of beta-sitosterol cause reductions of reactive cholesterol pools in mitochondria isolated from gonads of male goldfish (Carassius auratus)

beta-Sitosterol, a phytosterol found in high concentrations in pulp mill effluents, has been proposed as one of the causative agents for steroid depressions observed in fish exposed to pulp mill effluents. Previous studies have suggested a cholesterol-mediated mechanism; however, it is unknown how beta-sitosterol depresses gonadal steroidogenesis. In this study, adult male goldfish (Carassius auratus) were exposed for 24-31 days to beta-sitosterol (55% of a phytosterol mixture or 96% pure; 150 microg/g; Silastic implant) after which gonadal mitochondria were isolated. Pregnenolone production, an indicator of the size of the pool of reactive cholesterol, was then measured in the isolated mitochondria. Sterol exposure did not affect P450 side-chain cleavage enzyme (converts cholesterol to pregnenolone) activity but did decrease the size of the mitochondrial pool of reactive cholesterol, suggesting beta-sitosterol is impeding cholesterol transfer across the mitochondrial membrane. This finding is supported by the observation that 25-hydroxycholesterol, which passes through mitochondrial membranes without need for a membrane transporter, restores beta-sitosterol-induced reductions in pregnenolone production.     

Eel ATPase activity as biomarker of thiobencarb exposure

European eels (Anguilla anguilla) were exposed to a sublethal thiobencarb concentration of 0.22 mg/L in a flow-through system for 96 h. Mg(2+) and Na(+)-K(+) adenosine triphosphatase (ATPase) activities were evaluated in gill and muscle tissues at 2, 12, 24, 48, 72, and 96 h of thiobencarb exposure. Gill ATPase activities were rapidly inhibited from 2h of contact onward. Highest inhibition was registered for Na(+), K(+)-ATPase (85%) from 2 to 12h. Both Mg(2+) and total ATPase were inhibited (>73%) during the first hours of toxicant exposure. At the end of the exposure period (96 h) ATPase activities were still different from those of the controls (>50%). Significant inhibition was detected in Na(+), K(+)-ATPase activity (80%) in muscle tissue after 2h and it was maintained over the entire exposure time. However, Mg(2+)-ATPase and total ATPase showed only perturbations after 2 h of exposure. Eels were exposed to 0.22 mg/L of thiobencarb for 96 h and then a recovery period in herbicide-free water was allowed for 192 h. Gill and muscle samples were removed at 8, 24, 72, 96, 144, and 192 h and ATPase activity was evaluated. Following 144 h of recovery, Mg(2+)- and Na(+), K(+)-ATPase activities, as well as total ATPase activity, in gills of those animals previously exposed to 0.22 mg/L of thiobencarb were still significantly different compared to controls. Thiobencarb seems to act to alter the ionic profiles. Since ion-dependent ATPases are known to regulate the influx and efflux of ions across the membrane to maintain the physiological requirements of the cells, the inhibition of Na(+), K(+)-ATPase probably induced osmoregulatory perturbations. On the other hand, thiobencarb exposure causes increases in the muscle water content of A. anguilla. The results indicated that water content increased significantly (>100% higher than the controls) during the first 24 h of exposure.     

Suramin inhibits beta-bungarotoxin-induced activation of N-methyl-D-aspartate receptors and cytotoxicity in primary neurons

We demonstrated that beta-bungarotoxin (beta-BuTX), a snake presynaptic neurotoxin, exhibited a potent cytotoxic effect on cultured cerebellar granule neurons. The mechanism of action of beta-BuTX and the cytoprotective agents against beta-BuTX were studied. The neuronal death of cerebellar granule neurons induced by beta-BuTX was manifested with apoptosis and necrosis processes as revealed by neurite fragmentation, morphological alterations, and staining apoptotic bodies with the fluorescent dye Hoechst 33258. By means of microspectrofluorimetry and fura-2, we measured intracellular Ca2+ concentration, [Ca2+]i and found that [Ca2+]i was increased markedly prior to the morphological changes and cytotoxicity. The downstream pathway of the increased [Ca2+]i was investigated: there was increased production of free radicals, decreased mitochondrial membrane potential, and depleted cellular ATP content. MK801 and suramin effectively suppressed these detrimental effects of beta-BuTX. Furthermore, the [3H]MK801 binding was reduced by unlabeled MK801, beta-BuTX, and suramin. Thus, activation of N-methyl-D-aspartate (NMDA) receptors appeared to play a crucial role in the cytotoxic effects following betaBuTX exposure. In conclusion, the novel finding of this study was that a polypeptide beta-BuTX exerted a potent cytotoxic effect through sequential events, including activating NMDA receptors followed by increasing [Ca2+]i, ROS production, and impaired mitochondrial energy metabolism. Suramin, clinically used as a trypanocidal agent, was an effective antagonist against beta-BuTX. Data suggest that suramin might have value to detect the possible pathway of certain neuropathological disorders.     

Chronic myelomonocytic leukemia coexisting with B-cell chronic lymphocytic leukemia

Coexistence of B-cell chronic lymphocytic leukemia (B-CLL) and chronic myelomonocytic leukemia (CMML) is an unusal event, and to our knowledge, only four such cases have been reported in the literature. We report a 68-year-old white woman in whom these two diseases were diagnosed concomitantly. The diagnosis was made on the basis of peripheral blood count, morphology and immunophenotyping, and bone marrow cytology and histology. Interphase FISH analysis detected a 13q14.3 deletion in lymphocytes nuclei and no such abnormality in monocytes nuclei. The PCR analysis of IgH gene rearrangement in the bone marrow, as well as the peripheral blood lymphocytes, showed two different monoclonal IgH configurations as the result of biallelic clonal rearrangement of IgH genes suggesting an origin of lymphocytes from B-cell progenitors. The patient was originally treated with prednisone 1 mg/kg/day because of progressive significant thrombocytopenia, without improvement. Subsequently, she received one course of cladribine (2-CdA). Significant reduction of lymphocytes in the peripheral blood was observed. However, rapid increase of monocytes was seen shortly after the 2-CdA treatment. Subsequently, she received hydroxyurea (1.5 g/day) without hematological improvement. The patient died in January 2003, three months after diagnosis because of progression of both leukemias and associated pneumonia. Possible etiopathogenic relationship between both disorders is discussed.     

Fish,shellfish, and meat meals of the public in Singapore

Understanding different patterns of fish consumption is an important component of the assessment of risk from contaminants in fish. While there have been extensive studies of fish consumption in Western cultures, less attention has been devoted to the role of fish and meat in the diets of people in other cultures. A survey of 212 people living in Singapore was conducted to examine the relative importance of fish, shellfish, and other meat in their diets and to ascertain whether there were differences as a function of age, income, education or gender. As expected, fish and shellfish played an important role in their daily diets. On average, people ate fish in about 10 meals a week, chicken for eight meals, and shrimp and pork for about six meals each. While nearly 8% never ate fish, 18% ate fish at all 21 meals a week and over 20% ate shellfish for all 21 meals. Income explained about 14% of the variation in the number of fish meals consumed, and age explained about 8% of the variation in number of chicken meals per week. There were no gender differences in the number of meals of each type. People less than 26 years old ate significantly more pork, chicken, and other meat meals and fewer shellfish meals than older people. People with higher incomes ate significantly more fish meals than those with lower incomes. Chinese individuals ate significantly more meals of pork, chicken, and other meat than other ethnic groups, and they ate only 26% of their meals at home, while others ate 33% of their meals at home. The data indicate a great deal of variation in the number of meals of fish, shellfish, and other meats eaten by the people interviewed, making dietary and risk assessments challenging.     

LC-MS/MS法测定鱼肉中氯霉素残留

目的：建立鱼肉中氯霉素残留的液相色谱-串联质谱检测方法。方法：以氘代氯霉素为内标，乙酸乙酯超声振荡提取鱼肉组织中氯霉素，正己烷除去其中的脂肪，LC—MS／MS测定。结果：氯霉素检测的线性范围0．1—50μμ／L，／．2=0．9982。加标水平为0．5、2．5μg／kg时，平均回收率大于96％，相对标准偏差小于14％。鱼肉中氯霉素的定量检测下限为0．025μg／kg。结论：本法快速、灵敏，操作简便，检测结果准确，适用于鱼肉中氯霉素残留的检测。     

Associations of polybrominated diphenyl ethers (PBDEs) in breast milk and dietary habits and demographic factors in Taiwan

The aim of this study was to examine levels of PBDEs in breast milk associated with seafood consumptions of Taiwanese mothers. Our participants were selected from healthy women recruited between December 2000 and November 2001 from a medical center in central Taiwan. The congeners of PBDEs in 20 milk samples were analyzed by a gas chromatograph with a high resolution mass detector. The mean level of BDE47 in breast milk from mothers with pre-pregnant BMI <22.0 kg/m² had a significantly higher magnitude compared to those with pre-pregnant BMI 22.0 kg/m² (1.59 vs. 0.995 ng/g lipid, p = 0.041). We did not find significant correlations between PBDEs exposure levels and women’s age, parity, blood pressure, annual household income, and education level. Women who ate more fish and meat did not show significantly higher PBDE levels than those who ate less, but a significant difference in PBDE levels was demonstrated between the higher (2.15 ng/g lipid) and lower (3.98 ng/g lipid) shellfish consuming subjects (p = 0.002) after an adjustment for the confounders. The ratios of PCB153/BDE47, PCB153/BDE153, and PCB153/PBDEs were significantly correlated with frequent consumption of fish and shellfish. The PCB153/BDE153 ratio was not associated with the other dietary habits (i.e. meat). The ratios of PCB153/PBDEs may therefore be a new indicator for exposure as a result of seafood consumption.     

口服鱼油对急性胰腺炎大鼠炎性反应及免疫功能的影响

目的:评价添加鱼油的肠内营养对急性胰腺炎(AP)大鼠炎症反应及免疫功能的影响。方法:大鼠70只随机分为4组,分别为无胰腺炎组、AP-普通营养组,AP-玉米油营养组,AP-鱼油营养组。建立AP模型,术后第7天检测外周血中CD4 及CD8 细胞占总淋巴细胞的比例及CD4 /CD8 比值,TNF-αI、L-10浓度和IL-10/TNF-α变化。结果:AP-鱼油营养组大鼠较其它组TNF-αI、L-10浓度明显降低,且下调IL-10/TNF-α比值,CD4 /CD8 比值明显升高。结论:口服添加鱼油的肠内营养在减轻AP大鼠的炎性反应,调节其免疫功能方面优于其它组营养成分。     

Defluoridation of water using adsorbent derived from the Labeo rohita (rohu) fish scales waste: Optimization,isotherms, kinetics,and thermodynamic study

Fluoride ions have more affinity towards chitosan material. Fish scales waste is chitosan material generated in abundance in fish markets with virtually no value. The present research attempts to convert this waste to useful adsorbent which can remove fluoride from water. A novel adsorbent is thus developed from the Labeo rohita (rohu) fish scales waste giving thermal treatment for removal of fluoride from water using the batch study of adsorption. Taguchi optimization approach with L₁₆ orthogonal array was adopted to optimize the process parameters for achieving the maximum removal of fluoride. Using ANOM, pH 3; initial F^? concentration 5 mg.L^?1; mixing time 90 min; adsorbent dose 8 g.L^?1 and temperature 303 ^OK were obtained as optimum values providing a maximum fluoride reduction of 93.32%. Adopting ANOVA, the percentage contribution of each process parameter in descending order of sequence is initial F^? concentration 72.44%> pH 20.61% > temperature 2.96% > adsorbent dose 2.45% > contact time 1.55%. The fluoride sorption onto fish scales adsorbent was best fitted with the pseudo-second-order kinetic model and follows the Freundlich isotherm (K_F = 0.865, 1/n = 0.407) model. Thermodynamic parameters (ΔS = ?6.32 J mol^?1.K^?1, and ΔH = ?2.02 kJ mol^?1) suggested a spontaneous, exothermic nature of adsorption and indicates a physiosorption mechanism on a heterogeneous material. SEM and FTIR analysis for surface morphology showed the presence of hydroxyl functional groups is responsible for fluoride sorption. In the regeneration studies, the F ^– exhausted adsorbent was eluted with 0.1 N NaOH and rinsed with distilled water to prepare the adsorbent for the next cycle. The study indicates the removal of fluoride from water onto fish scales adsorbent is quite feasible, cost-effective, recyclable, and better utilization of locally available waste material into useful adsorbent for defluoridation of water.     

Dietary fish oil impairs induction of γ‐interferon and delayed‐type hypersensitivity during a systemic Salmonella enteritidis infection in rats

Snel J, Born L, van der Meer R. Dietary fish oil impairs induction of γ‐interferon and delayed‐type hypersensitivity during a systemic Salmonella enteritidis infection in rats. APMIS 2010; 118: 578–84. Fish oil that is rich in n‐3 polyunsaturated fatty acids markedly modulates immunological responses. Literature data indicate that the fish oil reduces cellular immunity and therefore impairs resistance to infections. We have investigated how dietary fish oil affects the immune response against a facultative intracellular pathogen, Salmonella enteritidis. Wistar rats were fed a diet containing 16% (w/w) of either fish oil or corn oil. After a 4‐week adaptation period, rats were intraperitoneally challenged with 4 × 10⁵ cfu of S. enteritidis. During the 14‐day infection period, urine was collected on a daily basis. At days 2 and 14, eight rats per group were sacrificed. Urinary nitrate, used as a marker for NO production, was lower on a fish oil diet during days 3–8. At day 2, serum γ‐interferon was 48 ± 7 pg/mL in the fish oil‐fed rats compared with 162 ± 52 pg/mL in the corn oil‐fed rats. No effects were found on living salmonella in liver and spleen. At day 14, as markers of an impaired T‐helper 1 (Th‐1) response, a 38% lower delayed‐type hypersensitivity responses and a lower salmonella‐specific IgG2b were observed in the fish oil‐fed rats. Although here dietary fish oil has affected only immune parameters, this impairment of the innate and Th‐1‐mediated immune response may have implications for the host resistance against other intracellular pathogens.