Laryngeal survey in glyphosate intoxication: a pathophysiological investigation

Respiratory aspiration is a serious potential complication of glyphosate-surfactant herbicide intoxication. From October 1, 1992 to June 30, 1996, we performed laryngeal evaluations in 53 cases to investigate the possible pathophysiological mechanism of glyphosate intoxication. There were 36 cases with significant laryngeal injury. The blood WBC count were significantly higher and the hospital stays were significantly longer in patients with laryngeal injury, when compared with patients with no laryngeal injury (Student t-test, P < 0.005). Laryngeal injury was strongly correlated with aspiration pneumonitis (mean 2 = 4.449, P < 0.05). We concluded that laryngeal injury may be the major cause of aspiration that leads to some degree of morbidity and mortality, following concentrated glyphosate-surfactant herbicide intoxication. Laryngeal survey may be indicated in cases of glyphosate-surfactant intoxication, to evaluate the severity of mucosal injury, and to apply adequate supportive management as early as possible to prevent from aspiration complications and even mortality.     

Comparative effects of strophanthidin in tilapia and human heart tissues

Production of growth factors may provide a mechanism for disease evolution in some leukemias. Interleukin-1 is a plelotropic cytokine with the ability to synergize with other growth factors as well as to stimulate their production and release. Autocrine and/or paracrine secretion of interleukin-1 has been implicated in the pathogenesis of both chronic and acute myelogenous leukemia. Recently, a series of both specific and nonspecific IL-1 inhibitory molecules have been identified. These include IL-1 receptor antagonist, soluble IL-1 receptors, IL-1-converting enzyme inhibitor, IL-4, IL-10 and IL-1-antisense. Early experiments demonstrating the ability of some of these molecules to inhibit acute and chronic myelogenous leukemia growth suggest that clinical trials of these compounds may provide a novel management approach in these malignancies. Here we review the potential biologic and therapeutic role of IL-1 and its inhibitors in the myeloid leukemias.     

Role of metabolism in ethyl carbamate-induced suppression of antibody response to sheep erythrocytes in female Balb/C mice

A possible role of metabolism by cytochrome P450 (P450) in ethyl carbamate-induced suppression of the antibody response to a T-cell-dependent antigen, sheep erythrocytes (SRBCs), was investigated in female Balb/C mice. When mice were treated with ethyl carbamate intraperitoneally for 14 consecutive days at 25, 50, 100, 200 and 400 mg/kg, the antibody response was significantly suppressed from 200 mg/kg. These doses also caused a decrease in thymus weight. An acute dosing of ethyl carbamate at 1 g/kg also caused not only a significant suppression of the antibody response, but also a decrease in thymus weight. The antibody response was most likely to be the IgM antibody response, which was demonstrated in a haemagglutination study. When mice were pretreated with phenobarbital (80 mg/kg) for 3 days to induce P450 enzymes, followed by administration of ethyl carbamate intraperitoneally for 7 consecutive days, the antibody response was more suppressed than in saline-pretreated controls. Moreover, a study using aminoacetonitrile, a P450 inhibitor, showed that the antibody response suppressed by ethyl carbamate was completely recovered by the inhibitor. The present results suggest that metabolism of ethyl carbamate by P450 may be the critical pathway to produce metabolites capable of suppressing the antibody response.     

Mutational spectrum induced by chromium(III) in shuttle vectors replicated in human cells: relationship to Cr(III)-DNA interactions

Trivalent chromium (Cr(III)), the ultimate species of chromium (VI) intracellular reduction, can associate with DNA forming Cr(III) monoadducts and DNA-DNA cross-links. However, the mutational specificity of Cr(III) has not been determined partly because Cr(III) has difficulty entering cells. In this study, we have characterized the types of Cr(III)-induced DNA lesions in two buffer systems and the mutational spectrum of Cr(III)-treated shuttle vectors replicated in human 293 cells. Plasmids were treated with Cr(III) in buffers consisting of either 10 mM potassium phosphate, pH 7.5 (designated as KP), or 0.2 mM Tris-HCl and 20 microM EDTA, pH 7.4 (designated as TE/50). The amounts of Cr(III) bound to DNA increased as Cr(III) concentration increased in both buffers; these Cr(III)-DNA associations were stable in both buffers during a 24-h dialysis. The electrophoretic mobility of supercoiled DNA was markedly retarded in samples treated with Cr(III) in TE/50 but not KP buffer, suggesting that Cr(III)-mediated DNA-DNA cross-links were generated in TE/50 but did not form in KP. Polymerase-stop assay showed that DNA polymerases were mostly blocked at the 3' adjacent bases of guanines on templates treated with Cr(III) in TE/50 but were not observed on those treated in KP. The signals of Cr(III)-mediated cross-links generated in TE/50 buffers were reduced when they were dialyzed against KP buffers. Similarly, Cr(III)-DNA monoadducts formed in KP were converted to primer-template cross-links by dialysis against TE/50. The mutation frequency of Cr(III) in the supF gene of pSP189 or pZ189 shuttle vectors replicated in human cells increased as Cr(III) concentration increased in both buffers. DNA sequencing analysis showed that single-base substitutions (61-68%), two-base substitutions (3-5%), and deletions (21-34%) were induced in similar frequencies in plasmids treated with Cr(III) in either TE/ 50 or KP. The Cr(III)-induced base-substitution hot spots are different from those occurring spontaneously. Cr(III) enhances G.C base substitutions, particularly G.C-->C.G transversions, at 5'GA, 5'CG, and 5'AG sites. Base-substitution hot spots did not correlate with strong polymerase-stop sites, suggesting that base substitutions are derived from Cr(III) monoadducts, not from DNA-DNA cross-links.     

Possible involvement of plasmids in degradation of malathion and chlorpyriphos by Micrococcus sp

Culture is the basic method in bacteriology. It allowed the discovery of Helicobacter pylori. Problems in the culture of this fragile, slow-growing bacterium concern transport and processing in the laboratory, but they can be solved. Culture has a 100% specificity. When performed properly, it has a sensitivity in the range of the other best diagnostic methods for Helicobacter pylori. It allows strain typing and, most importantly, susceptibility testing to antibiotics, because an increased rate of acquired resistance of Helicobacter pylori is currently observed. Culture must be performed in clinical trials, at least when antibiotics, to which Helicobacter pylori may be resistant, are used. In clinical practice, culture and susceptibility testing can generally be restricted to treatment failures. However, it is important to monitor Helicobacter pylori susceptibility to antibiotics at a national or regional level in order to give recommendations for primary treatment.     

Concurrent primary carcinoma of the gallbladder and acute cholecystitis

BACKGROUND/AIMS: Primary carcinoma of the gallbladder is rare and associated with a late diagnosis and poor prognosis. Concurrent acute cholecystitis frequently obscures the presence of carcinoma. The information regarding gallbladder carcinoma with acute cholecystitis is limited. In order to better understand the presentation of gallbladder carcinoma with acute cholecystitis, we retrospectively reviewed the data of patients with primary carcinoma of the gallbladder. METHODOLOGY: The data of 86 patients with primary carcinoma of the gallbladder treated between 1979 and 1994 were compiled and reviewed. The patients were divided into 2 groups: Group 1 (with acute cholecystitis, 21 patients) and Group 2 (without cholecystitis, 65 patients). Clinicopathological comparisons were made and evaluated between these two groups RESULTS: The average age of Group 1 patients was older than that of Group 2 patients (75+/-2 years vs. 63+/-2 years; p<0.05). Three Group 1 patients presented with sepsis. The interval between the onset of symptoms and hospital admission in Group 2 patients was significantly (p<0.05) longer than that in Group 1 patients (243+/-95 days vs. 20+/-11 days). Leukocytosis (>11,000/mm3) was more common in Group 1 patients than in Group 2 patients (47.6% vs. 15.4%). Jaundice was more common in Group 2, and fever was common in Group 1. The majority of Group 2 gallbladder cancers were stage V (75.4%). In contrast, 52.4% of Group 1 gallbladder cancers were stage III and 38.1% were stage V. The 30-day postoperative mortality rate in Group 1 and Group 2 patients was 9.5% and 7.7%, respectively. The cumulative survival of Group 1 patients was not different from that of Group 2 patients (log-rank test, p>0.05). CONCLUSIONS: Age, the interval of symptoms prior to admission, the location of abdominal pain, fever, leukocytosis, and the absence of jaundice suggested the presence of acute cholecystitis in gallbladder carcinoma. A high index of suspicion of the disease, intraoperative examination of gallbladder specimens, and more aggressive surgical treatment may improve patient survival.     

Priming and aging: an electrophysiological investigation of N400 and recall

Twenty young (20.5 years) and 20 middle-aged academics (57.2 years) performed a priming-recall task which was presented in three blocks. In each block, participants read 40 word pairs after which a recall task had to be carried out. Half of the word pairs were highly associated while the others were low associated. Targets showed the N400 of the middle-aged group to be both delayed and smaller in amplitude for low-associated items. N400 of primes, however, showed no age-related latency difference but was smaller for the middle-aged group due to a positive shift. It is argued that this shift possibly indicates age differences in semantic activation or buildup of context. A reanalysis showed individual differences in word pair processing to depend on recall performance. In general, high recallers were found to show a much larger differentiation between low- and high-associated targets. This resulted from a much larger N400 component elicited by low-associated targets and a more positive ERP in the N400-region for the high-associated targets. It is suggested that the middle-aged subjects activated the expected target word to a level at least equivalent to the younger subjects, but that the activated network itself was larger/less selective particularly in subjects showing a low recall.