Selenium and zinc levels in volatile substance abusers

Plasma and erythrocyte levels of selenium (Se) and zinc (Zn) have not been investigated in volatile (inhalant) substance abusers previously, although changes in the activities of antioxidant enzymes resulting from oxidative damage caused by various constituents of volatile substances have been shown in a few animal and human studies. Concentrations of these two elements in erythrocytes and plasma of 37 adolescents with inhalant abuse were measured by atomic absorption spectrophotometry and compared with those of 37 age-matched healthy controls. Erythrocyte and plasma levels of Se and plasma level of Zn were significantly lower in the study group when compared to the control group. Chronic inhalation of volatile substances can decrease the plasma levels of Se and Zn and, thus, may lead to a decrease in the activity of antioxidant enzyme systems in adolescent abusers. The role of Se and Zn supplementation in children with inhalant abuse remains to be determined considering the reduced antioxidant activity resulting from deficiency of these trace elements.     

Combined effects of cadmium and nickel on testicular xenobiotic metabolizing enzymes in rats

When male rats were given a single dose of cadmium (Cd) (3.58 mg CdCl₂·H₂O/kg, ip) 72 hr prior to sacrifice, the testicular 7-ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) activities toward the substrates 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB), ethacrynic acid (EAA), 1,2-epoxy-3-(p-nitrophenoxy)-propane (EPNP), and cumene hydroperoxide (CHPx) decreased significantly as compared to controls. Cd also inhibited reduced glutathione (GSH) level while increasing the lipid peroxidation (LP) level significantly. When the animals were given a single dose of nickel (Ni) (59.5 mg NiCl₂·6H₂O/kg, ip) 16 hr prior to sacrifice, significant decreases were observed in EROD and GST activities toward CDNB, EAA, EPNP, and CHPx, and GSH level. No significant alterations were noted in DCNB GST activity and LP level by Ni. For the combined treatment, rats received the single dose of Ni 56 hr after the single dose of Cd and were killed 16 hr later. In these animals, lesser depressions were observed on EROD activity and LP level than those of Cd alone. The combination of metals significantly inhibited GST activities and GSH level but not to a greater degree than noted by Cd or Ni alone. Plasma testosterone levels of Cd-, Ni-, and combination-treated rats decreased significantly compared to controls. The strongest depression was achieved by Cd alone. Cd, both alone and in combination with Ni, increased the tissue Ni uptake significantly. Ni, however, did not produce such an effect on the tissue uptake of Cd in either case. Cd treatment caused interstitial edema and coagulation necrosis in seminiferous tubules and also caused fibrinoidal necrosis in vascular endothelium. Ni treatment did not produce any pathological testicular alterations compared to controls. Combined treatment produced fewer pathological alterations (i.e., only interstitial edema) than that of Cd treatment. These results reveal that the combination of Cd and Ni does not have a synergistic effect on testicular xenobiotic metabolizing enzymes, and in contrast, Ni has an ameliorating effect on pathological disturbances caused by Cd alone in the rat testis.     

Trichothecenes and zearalenone production by fusarium species isolated from Argentinean black beans

Isolates of Fusarium species obtained from freshly harvested bean grains for human consumption collected from different Argentinean regions, were investigated for their ability to biosynthesise trichothecenes and zearalenone either on rice grains or beans. Low incidence of toxigenic fungi was observed. These mycotoxigenic species produced several toxins when grown on rice but none or little amount when cultured on beans. The results of this report suggest that contamination of Argentinean beans with Fusarium mycotoxins will not be common and therefore people would be at low mycotoxicosis risk through consumption of beans.     

EPR study of non-covalent spin labeled serum albumin and hemoglobin

Electron Paramagnetic Resonance (EPR) was used to investigate the Tempyo spin label (3-carbamoyl-2,2,5,5-tetramethyl-3-pyrrolin-1-yloxy) as a report group for the interactions and the conformational changes of lyophilized bovine serum albumin (BSA) and bovine hemoglobin (BH), as function of pH values in the range 2.5-11. The EPR spectra are similar with those of other non-covalently spin label porphyrins in frozen solution at very low temperatures. This behavior indicated a possible spin-spin interaction between the hemic iron and the nitroxide group. The changes in the EPR spectra as function of the pH are discussed in terms of conformational changes of the proteins. Spectral simulations and magnetic EPR parameters reveal the following: (i) one single paramagnetic species, with Gaussian line shape, was used for the best fits of experimental spectra in the case of serum albumin samples; and (ii) a weighted sum of Lorentzian and Gaussian line shape in the case of hemoglobin samples. The representation of correlation time vs. pH, reveals a dependence of degree of immobilization of spin label on the conformational changes of proteins in acidic and basic environment.     

Prognostic role of natural killer cells in pediatric mixed cellularity and nodular sclerosing Hodgkin's disease

OBJECTIVE: To study natural killer cells' spontaneous cytotoxic capacity against tumor cells and their prognostic significance in classical Hodgkin's disease. STUDY DESIGN: Thirty-eight pediatric mixed cellularity and nodular sclerosing Hodgkin's disease patients were included in the study. Immunohistochemical staining was performed for natural killer cells in the background using the monoclonal antibody CD57 in serial sections of B5-formalin-fixed, paraffin-embedded tissue blocks. CD57-positive cells were counted with an immersion objective among 5,000 cells on representative areas of the tumors. The degree of natural killer cells was classified as low (<150 cells) or high (> or = 150 cells). Multivariate regression analysis was performed to determine the differences between patients with and without relapse. RESULT: The mean of CD57-positive cell numberfor all the cases was 173.42 +/- 117.34 (range, 20-500). CD57-positive cells were high in 21 cases and low in 17. The mean of CD57-positive cell numbers was 191.85 +/- 115.33 in the disease-free group and 84.44 +/- 57.90 in the relapsing group. Log rank analysis showed statistical significance between event-free survival and number of CD57-positive cells (P = .0207). CONCLUSION: In multivariate analysis, CD57 expression proved to be a prognostic factor independent from otherfactors. As a result, CD57 expression by background natural killer cells may be used as a prognostic parameter in mixed cellularity and nodular sclerosing Hodgkin's disease.     

Synthesis of new sulfonamide inhibitors of carbonic anhydrase

Four different derivatives of aromatic sulfonamides have been synthesized: 1,2-bis[(4-sulfonamidobenzamide)ethoxy]ethane (SBAM), 1,2-bis[(4-sulfonamidobenzoate)ethoxy]ethane, 1,2-bis[(2,4-dichloro-5-sulfonamidobenzamide)ethoxy]ethane, and 1,2-bis[(2,4-dichloro-5-sulfonamidobenzoate)ethoxy]ethane. SBAM is a most potent inhibitor on ciliary epithelium carbonic anhydrase and is approximately 13 times more active against carbonic anhydrase isoform II than against isoform I.     

Optimization of manganese peroxidase and laccase production in the South American fungus<Emphasis Type="Italic"> Fomes sclerodermeus</Emphasis> (Lév.) Cke

Fomes sclerodermeus produces manganese peroxidase (MnP) and laccase as part of its ligninolytic system. A Doehlert experimental design was applied in order to find the optimum conditions for MnP and laccase production. The factors studied were Cu²⁺, Mn²⁺ and asparagine. The present model and data analysis allowed us not only to define optimal media for production of both laccase and MnP, but also to show the combined effects between the factors. MnP was strongly influenced by Mn²⁺, which acts as an inducer. Under these conditions Cu²⁺ negatively affected MnP activity. At 13 days of growth 0.75 U ml^–1 were produced in the optimized culture medium supplemented with 1 mM MnSO₄ and 4 g l^–1 asparagine. The laccase titer under optimized conditions reached maximum values at 16 days of growth: 13.5 U ml^–1 in the presence of 0.2 mM CuSO₄, 0.4 mM MnSO₄ and 6 g l^–1 asparagine. Mn²⁺ promoted production of both enzymes. There were important interactions among the nutrients evaluated, the most significant being those between Cu²⁺ and asparagine.     

Shifts in immunoglobulin (IgG,IgM and IgA) levels in the milk of southern elephant seals,at Potter Peninsula,King George Island,Antarctica

We quantified immunoglobulins (Ig) in mammary secretions of 12 female southern elephant seals ( Mirounga leonina) at King George Island, Antarctica, using single radial immunodiffusion on agarose plates. Seals were chemically immobilized for milk sample collection at four time points during the 3- to 4-week suckling period. All three major mammalian immunoglobulins (IgG, IgM, IgA) were detected in southern-elephant seal milk. Total immunoglobulin levels and the ratio of Ig subclasses varied throughout the suckling period. Total immunoglobulin levels were highest on the 1st day of lactation, when they represented over 57% of the mean total protein concentration of the milk, and declined steadily throughout lactation, representing approximately 40% of the mean total protein concentration at the end of the suckling period. IgG was the most abundant immunoglobulin class (85.93-93.78% of total milk immunoglobulins), followed by IgM (6.06-13.93%), and IgA (0.14-0.23%). There was no significant difference in IgA levels throughout the suckling period. IgG levels were significantly lower during the second stage (3-6 days post-parturition) than during the first, third or fourth stages (1, 13-15, and 19-25 days post-parturition, respectively). IgM levels were highest during the first stage of lactation; these values were significantly higher than levels measured during the second, third and fourth stages of lactation. Transfer of passive immunity from female to offspring in other mammalian species is correlated with the subclass of immunoglobulin secreted in the milk; species acquiring passive immunity in utero, via the placenta, secrete a preponderance of IgA, whereas species acquiring immunity post-partum, via lacteal secretions and gut resorption, secrete a preponderance of IgG. The Ig patterns and concentrations observed in our study of southern elephant seals are consistent with an important role of post-partum transmission of passive immunity during the pinniped lactation period.     

Role of vascularization in determining the time of hypoxic-ischemic encephalopathy in the neonate

OBJECTIVE: To examine the role of vascularization in determining the time of hypoxic-ischemic encephalopathy (HIEP). STUDY DESIGN: Brain sections of 126 neonatal autopsy cases were examined for edema, gliosis, congestion, inflammation and ischemia. Capillary vessels were examined with both reticulum stains and antibody against CD34. Vascular surface density (VSD) and number of vessels per stroma (NVES) were calculated by stereologic methods. RESULTS: Among 126 cases, 64 were male (50.8%) and 62 female (49.2%). In 25 cases HIEP was observed; 14 had a pregnancy history of hypertension, eclampsia or diabetes mellitus in the mother, with fetal distress or underdeveloped features. Statistically, NVES was strongly related to primary HIEP. However, the HIEP and non-HIEP cases revealed no differences in NVES and VSD means. CONCLUSION: Vascularization, especially NVES, helps in determining whether an HIEP case is pregnancy related or due to end-stage changes of dying, but is not an indicator of HIEP.