Contamination of tea leaves by anthraquinone: The atmosphere as a possible source

The detection of anthraquinone in tea leaves has raised concerns due to a potential health risk associated with this species. This led the European Union to impose a maximum residue limit (MRL) of 0.02 mg/kg for anthraquinone in dried tea leaves. As atmospheric contamination has been identified as one of the possible sources of anthraquinone residue, this study investigates the contamination resulting from the deposition of atmospheric anthraquinone using a global chemical transport model that accounts for the emission, atmospheric transport, chemical transformation, and deposition of anthraquinone on the surface. The largest contribution to the global atmospheric budget of anthraquinone is from residential combustion followed by the secondary formation from oxidation of anthracene. Simulations suggest that atmospheric anthraquinone deposition could be a substantial source of the anthraquinone found on tea leaves in several tea-producing regions, especially near highly industrialized and populated areas of southern and eastern Asia. The high level of anthraquinone deposition in these areas may result in residues in tea products exceeding the EU MRL. Additional contamination could also result from local tea production operations.

Heterogeneous Nucleation Drives Particle Size Segregation in Sequential Ozone and Nitrate Radical Oxidation of Catechol

Secondary organic aerosol formation via condensation of organic vapors onto existing aerosol transforms the chemical composition and size distribution of ambient aerosol, with implications for air quality and Earth's radiative balance. Gas-to-particle conversion is generally thought to occur on a continuum between equilibrium-driven partitioning of semivolatile molecules to the pre-existing mass size distribution and kinetic-driven condensation of low volatility molecules to the pre-existing surface area size distribution. However, we offer experimental evidence in contrast to this framework. When catechol is sequentially oxidized by O₃ and NO₃ in the presence of (NH₄)₂SO₄ seed particles with a single size mode, we observe a bimodal organic aerosol mass size distribution with two size modes of distinct chemical composition with nitrocatechol from NO₃ oxidation preferentially condensing onto the large end of the pre-existing size distribution (∼750 nm). A size-resolved chemistry and microphysics model reproduces the evolution of the two distinct organic aerosol size modes─heterogeneous nucleation to an independent, nitrocatechol-rich aerosol phase.

Conyza bonariensis as an alternative host for Colletotrichum species in Argentina

AIMS

This study investigated the diversity of Colletotrichum isolates recovered from Conyza bonariensis leaves through the use of morphological characteristics, growth rate, carbon sources utilization and phylogenetic analysis.

METHODS AND RESULTS

In all, 30 Colletotrichum isolates recovered from C. bonariensis leaves showing symptoms of disease were included in the present study. Based on the analysis of morphology and sequences, the isolates were distributed into six Colletotrichum species complexes. The concatenated alignment of GAPDH and ITS sequences showed that 20 out of 30 isolates were included in four species complexes which comprise the most important pathogens causing anthracnose in soybean or anthracnose and stalk rot in maize: C. truncatum, C. orchidearum, C. gloeosporioides and C. graminicola. The remaining 10 isolates were included in the C. boninense and C. destructivum species complexes or could not be assigned to any complex with the available information.

CONCLUSION

Weeds belonging to genus Conyza are host to soybean and maize potential pathogenic species of Colletotrichum and could have a role as inoculum reservoir for cross contamination in the agroecosystem.

SIGNIFICANCE AND IMPACT OF THE STUDY

The combined use of morphological, kinetics and physiological parameters of growth and phylogenetic analysis in Colletotrichum isolates from Conyza leaves allowed the detection of species complexes previously not identified in Argentina.

In vitro influence of bacterial mixtures on Fusarium verticillioides growth and fumonisin B1 production: effect of seeds treatment on maize root colonization

AIMS

Enterobacter cloacae, Microbacterium oleovorans, Pseudomonas solanacearum and Bacillus subtilis were investigated in order to evaluate: (i) the inoculum size of two bacterial mixtures on Fusarium verticillioides growth and fumonisin B1 production in vitro at different water activities and (ii) the efficacy of a seed treatment with the best bacterial mixture on F. verticillioides root colonization in greenhouse studies.

METHODS AND RESULTS

The influence of bacterial mixtures (1 = E. cloacae and M. oleovorans and 2 = P. solanacearum and B. subtilis) to antagonize 13 F. verticillioides strains at different inoculum concentrations (10(8), 10(9) and 10(10) cells ml(-1)) and water activities (0.937, 0.955 and 0.982 aW) were examined. Antibiosis, growth rate and fumonisin B1 production were determined. Bacterial mixture 1 proved to exert the most effective control. Seed treatment with mixture 1 at 10(8) cells ml(-1) had the best inhibitory effect on F. verticillioides root colonization.

CONCLUSIONS

These results suggest that the combination E. cloacae and M. oleovorans has the potential for the biological control of F. verticillioides as a maize seed inoculant.

SIGNIFICANCE AND IMPACT OF THE STUDY

The application of this knowledge contributes to prevent the vertical transmission of F. verticillioides.

Biocontrol of Bacillus subtilis against Fusarium verticillioides in vitro and at the maize root level

Bacillus species as a group offer several advantages over other bacteria for protection against root pathogens because of their ability to form endospores, and because of the broad-spectrum activity of their antibiotics. The objectives of this work were to determine the ability of strains of Bacillus to inhibit Fusarium verticillioides growth and fumonisin B(1) accumulation in vitro, and to evaluate the ability of the best bacterium for preventing rhizosphere and endorhizosphere colonization by F. verticillioides. Bacterial populations from the maize rhizoplane were obtained, and the capacity of ten Bacillus strains to inhibit fungal growth and fumonisin B(1) accumulation in vitro was assayed. According to these results, B. subtilis CE1 was selected as the best antagonist for testing maize root colonization of F. verticillioides. Bacillus subtilis CE1 at 10(8) and 10(7) CFU ml(-1) inocula was able to reduce rhizoplane and endorhizosphere colonization of F. verticillioides in greenhouse trials. The strain B. subtilis CE1 could be a potential biological control agent against F. verticillioides at the root level.

Altered ganglioside composition in virally transformed rat embryo fibroblasts

The composition of gangliosides was examined in a normal rat embryo fibroblast cell line (REF52) and in two viral transformants: a polyoma transformant (REF52-PyMLV) and a simian viral 40 transformant (REF52-SV40). The distribution of gangliosides in the cell lines was determined using gas-liquid chromatography and high-performance thin-layer chromatography. N-acetylneuraminic acid was the predominant sialic acid species detected in the three cell lines. The total ganglioside concentration (microgram/100 mg dry weight of cells) in the normal, PyMLV, and SV40 lines was 144.7 +/- 10.4, 153.8 +/- 9.2, and 86.1 +/- 6.8, respectively. Gangliosides GM3, GM2, GM1, and GD1a were the major species in the normal and transformed lines. The distribution of these gangliosides, however, differed markedly between the normal and the transformed lines and also between the transformed lines themselves. The transformed cells also differed from the normal cells in growth rate, morphology, and social behavior. The cell line with highest GM3 content (PyMLV) formed islands, whereas the normal and SV40 cell lines, which had lower GM3 levels, grew as monolayers. The findings suggest that PyMLV and SV40 transformation can have multiple and different effects on cellular ganglioside distribution and growth behavior.

Growth factor requirements of normal and polyomavirus middle T gene transformed REF52 cells in serum-free medium: indications of a reduced vasopressin requirement and its relationship to the control of phosphatidylinositol metabolism

The growth factor requirement of normal and polyomavirus middle T gene transformed REF52 cells was studied in serum-free medium in an attempt to elucidate the possible linkage between an altered growth factor requirement and one or more altered physiological properties of the transformed cells. For optimal growth, REF52 cells required vasopressin, epidermal growth factor (EGF), high-density lipoprotein (HDL), hydrocortisone, insulin, transferrin, and fibronectin. Deletion of vasopressin or hydrocortisone from the medium resulted in a 50 to 60% reduction in cell growth and the deletion of HDL, transferrin, or the combination of EGF and vasopressin led to an 80 to 90% growth retardation. The same medium supported the growth of the transformed variant (PyMLV-REF52) at a rate comparable to that of 10% serum, and deletion of hydrocortisone, vasopressin, or the combination of EGF and vasopressin had virtually no effect on PyMLV-REF52 cell growth. In vasopressin-deleted medium, vasopressin elicited a rapid increase of intracellular inositol phosphate levels in REF52 cells and the control of phosphoinositide turnover was strictly regulated. In contrast, both cell proliferation and intracellular inositol phosphate levels of PyMLV-REF52 cells were not affected by vasopressin treatment under identical culture conditions, and control of phosphoinositide metabolism was lost. Thus, a correlation may exist between the trigger of a mitogenic signal and the stimulation of the phosphoinositol pathway by vasopressin in REF52 cells and this relationship was disrupted in PyMLV-REF52 cells.

The penetration of formulated Guthion spray through selected fabrics

A technique for comparing pesticide penetration through fabric was devised. It involved passing fabric swatches through a controlled spray system and measuring the pesticide residue transferring on and through the tested fabric. Six variations in fabric were selected for testing: 100% cotton woven chambray, Scotch-guard treated chambray, Tyvek, Crowntex, and two variations of Gore Tex. Guthion (azinphos-methyl) was chosen as the insecticide for controlled use in this experiment because of its widespread use and relatively high toxicity. Gas chromatographic analysis of the amount of Guthion transferred through the outer fabric was made by the use of analysis of variance (ANOVA) and Duncan's multiple range test. The ANOVA for experiment replication showed no significant difference among the replications of each fabric. The treatment ANOVA was highly significant at the 0.01 level. Duncan's multiple range test further analyzed the differences in the treatment, and three groups were found to be significantly different from each other. The two types of Gore Tex, Tyvek and Crowntex comprised the group permitting the least penetration Scotch-guard treated chambray followed, and untreated chambray allowed the greatest penetration.

Conversion of glutathione to glutathione disulfide, a catalytic function of gamma-glutamyl transpeptidase

A purification procedure, based on that previously used for rat kidney gamma-glutamyl transpeptidase, was used for the purification of glutathione oxidase (which converts glutathione to gluthathione disulfide). The two activities co-purified, the ratio of the activities remaining constant through all steps of the isolation procedure. The purified enzyme was separable into 12 isozymic species by isoelectric focusing. All 12 isozymes exhibited a constant ratio of transpeptidase to glutathione oxidase activities, strongly supporting the conclusion that conversion of glutathione to glutathione disulfide is a catalytic function of gamma-glutamyl transpeptidase. Modulation of oxidase activity by inhibitors and acceptor substrates of transpeptidase is discussed in relation to the possible glutathione binding sites involved in gamma-glutamyl transfer and oxidase activities of the enzyme.

Prognostic value of a persistently positive technetium-99m stannous pyrophosphate myocardial scintigram after myocardial infarction

Technetium-99m stannous pyrophosphate myocardial scintigrams were obtained in 138 clinically stable patients 32.7 +/- 47.3 weeks (range 6 to 260) after acute myocardial infarction. Of the 138 patients, 74 (54 percent) had a persistently positive scintigram. Patients with such a scintigram were more likely to have severe angina pectoris, compensated congestive heart failure, anterior location of acute myocardial infarction, Q waves and S-T segment elevation in the electrocardiograms, cardiomegaly, left ventricular dyssynergy (dyskinesia or global dyssynergy), and an ejection fraction of less than 50 percent. During a follow-up period of 11.6 +/- 6.9 months after scintigraphy, 42 percent of the patients with a persistently positive scintigram had either a cardiac death, a nonfatal myocardial infarction, unstable angina pectoris or decompensated congestive heart failure compared with 13 percent of the patients with a negative scintigram (P less than 0.001). Of the 14 patients with cardiac death, 13 (93 percent) had a persistently positive scintigram. A persistently positive scintigram not only was the best single predictor of cardiac death and combined end points, but also added significantly to the predictive ability of the other clinical variables, including age, location of acute myocardial infarct, clinical status, electrocardiographic findings, and chest X-ray findings. It is concluded that technetium-99m stannous pyrophosphate myocardial scintigraphy has prognostic value in patients after acute myocardial infarction.

Systolic time intervals before and after cardioversion of atrial fibrillation

The effect of cardioversion of atrial fibrillation to normal sinus rhythm on systolic time intervals was evaluated in 18 patients. Variable results in the left ventricular ejection time index, the external isovolumic contraction time (EICT), and the ratio of the left ventricular ejection time over the EICT (LVET/EICT) and shortening of the preejection period (PEP) (P less than 0.01), the PEP index (PEPI) (P less than 0.005), and the ratio of PEP/LVET (P less than 0.001) occurred at five hours after cardioversion. Six (33 percent) of the 18 patients developed recurrent atrial fibrillation within one month after cardioversion, and the hearts of 12 (67 percent) of the 18 patients remained in sinus rhythm for one to ten months after cardioversion. Four of five patients in whom the EICT became worse at five hours after cardioversion and two of two patients in whom the PEPI became worse at five hours after cardioversion developed recurrent atrial fibrillation. The EICT and PEPI at five hours after cardioversion may be helpful in predicting subsequent recurrence of atrial fibrillation.

Fasting decreases triiodothyronine receptor capacity

Fasting decreases the ratio of hepatic nuclear to serum triiodothyronine (T3) by diminishing the binding capacity of nuclear T3 receptors. In combination with the lower serum T3 concentration caused by fasting, the decrease in receptor content results in a marked decrease in nuclear T3-receptor complexes. The changes in T3 receptor content and circulating T3 in fasted animals appear to be independent synergistic adaptations for caloric conservation in the fasted state. Unlike changes in hormonal level, the modification of nuclear receptor content provides a mechanism that may protect cells with a low caloric reserve independently of the metabolic status of the whole animal.

Correlation of mean pulmonary artery wedge pressure, left atrial dimention, and PTF-V1 in patients with acute myocardial infarction

The mean pulmonary artery wedge pressure (PAWP), left atrial dimension (LAD) by echocardiography, and PTF-V1 in the electrocardiogram were correlated with each other in 16 patients with acute myocardial infarction in the control period and after therapeutic intervention with either Dextran or furosemide and/or nitroprusside. No significant correlation was found between a normal control PAWP and the LAD. An increased control PAWP correlated well with an increased LAD (r = 0.98). No significant correlation was found between the LAD and the PAWP whether normal or elevated after therapeutic intervention. No significant correlation was found between the PAWP whether normal or elevated and the PTF-V1. No significant correlation was found between the LAD and the PTF-V1. We conclude in acute myocardial infarction 1) the PTF-V1 is not useful in assessing PAWP before or after therapeutic intervention, 2) the LAD correlates poorly with a normal control PAWP but correlates well with an elevated control PAWP, and 3) the LAD cannot be used to assess PAWP after therapeutic intervention.

High reversion of atrial flutter to sinus rhythm after atrial pacing in patients with pulmonary disease

The effect of atrial pacing on atrial flutter was evaluated in 36 consecutive episodes in 33 patients. Seventeen episodes occurred in a pulmonary setting, 14 of these in patients with chronic pulmonary disease. Twenty-four (67 percent) of the 36 episodes converted to sinus rhythm within one minute after atrial pacing. In nine (25 percent) of the 36 episodes, atrial fibrillation developed after atrial pacing. Atrial flutter was not affected by atrial pacing in three (8 percent) of the 36 episodes.n 12 (86 percent) of the 14 patients with chronic pulmonary disease and in 14 (82 percent) of the 17 patients in whom a pulmonary setting was responsible for atrial flutter, atrial pacing caused conversion to sinus rhythm. Atrial pacing may be the treatment of choice for atrial flutter in patients with pulmonary disease because of its excellent rate of success in this subgroup whose risk of cardioversion is increased by poor anesthetic tolerance and hypoxia.

Effect of ethanol on angina pectoris

We evaluated the effect of ethanol on exercise performance until angina in 12 patients in a double-blind, randomized study. The mean resting heart rate times systolic blood pressure was not changed after Fresca but was increased after 2 ounces of ethanol (P less than 0.001) and after 5 ounces of ethanol (P less than 0.01). Compared to the control periods, the mean exercise time until angina was not different after Fresca but was decreased after 2 ounces of ethanol (P less than 0.001) and after 5 ounces of ethanol (P less than 0.001). Compared to the control periods, the mean maximal ischemic ST-segment depression after angina was not changed after Fresca but was increased after 2 ounces of ethanol (P less than 0.01) and after 5 ounces of ethanol (P less than 0.001). Drinking 5 ounces or 2 ounces of ethanol decreases exercise duration until angina and increases ischemic ST-segment depression after angina.

Surgical Management of Torticollis

Twenty-one patients with torticollis have been operated upon during the 1946–1973 period. The site of surgical attack has changed with time and better understanding of physiopathology. Thus the first 8 patients had had cervical motor rhizotomies plus accessory neurotomies. The remaining 13 cases all had stereotactic lesions 6 of them complemented with peripheral procedures. In the first group with exclusive stereotactic destructions the disease type was: (a) rotational torticollis with dystonic background in 6 patients and (b) 1 pure horizontal form. In the first subgroup (a) all had VO thalamotomies bilaterally in all but 2 cases which were combined with pallidotomy or nucleus preinterstitialis. The second subgroup (b) had subthalamotomy. In the second group the disease type was: retrocollis in 2 cases and rotational torticollis in 4, all of them with severe myoclonic component. All had bilateral VO thalamotomies and all had additional bilateral motor rhizotomies combined in 4 cases with XIth neurotomy. Results for the first group were fair for the 6 cases (a) with dystonic component and excellent for the (b) pure horizontal form. However in the second group we were forced to add cervical motor rhizotomies and/or accessory neurotomy to improve results. The patients seem to do better with the lower stereotactic targets.

Decarboxylation of 3,4-dihydroxyphenylalanine (DOPA) by erythrocytes: a reaction promoted by methemoglobin and other ferriheme proteins

The decarboxylation of DOPA by erythrocyte hemolysates differs from DOPA decarboxylation catalyzed by aromatic aminoacid decarboxylases that contain vitamin B(6) in several significant respects. The ability of erythrocyte hemolysates to decarboxylate DOPA is associated with interaction between DOPA and methemoglobin; the ferriheme protein is reduced and DOPA is decarboxylated, probably after oxidation to a quinone intermediate. An analogous reaction takes place between DOPA and other ferriheme proteins, such as metmyoglobin and cytochrome c. This phenomenon may be of significance in relation to the side effects observed in patients with Parkinson's disease who are treated with very large doses of DOPA.

A Mössbauer study of ferri- and ferrocytochrome c

The Mössbauer spectra of horse heart ferri- and ferrocytochrome c were obtained at room temperature using lyophilized powders. The Mössbauer data indicate that the iron in both lyophilized samples is in a low-spin state. The high quadrupole splittings suggest that the iron atom is in an asymmetric ligand field. Upon reduction the asymmetry increases, suggesting a change in the bonding between the protein moieties and the iron atom.