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1.
Phlebotomus langeroni collected from a leishmaniasis endemic focus at Et Agamy, Alexandria, Egypt, were found to have fed on blood from man, dogs (Canis familiaris) and rats (Rattus rattus). The effect of the kind of blood meal on the development and the life-cycle of L. infantum and L. major in laboratory reared P. langeroni was therefore investigated. A membrane feeding technique was used to infect sand flies. Gut smears of infected females were examined immediately after feeding and daily for 16 days. Nectomonads and short promastigote forms of L. infantum or L. major were detected in females fed on human, dog and rat bloods at all intervals. Paramastigotes (infective stage) were present only in females fed on dog blood containing L. infantum or L. major and in those fed on rat blood containing L. major. It is concluded that among the factors influencing the Leishmania-phlebotomus relationship is the natural medium in which the parasite is present in vivo. The blood of the natural reservoir host(s) is the key factor for the development of the infective parasite form in the sand fly and P. langeroni could be considered a potential vector for transmitting L. infantum from dogs and L. major from rats and dogs but not from man. This investigation offers a new concept for the study of interactions among vector, host and parasites in Leishmania transmission.  相似文献   

2.
The oxidation states of intracellular myoglobin and cytochrome oxidase aa3 were monitored by reflectance spectrophotometry in isolated perfused rat hearts subjected to an acutely magnesium deficient environment. After exposure to low extracellular [Mg2+]o (i.e., 0.3 mM) for 30 min, more than 80% of the oxymyoglobin converted to its deoxygenated form. The level of reduced cytochrome oxidase aa3 also increased about 80% in low [Mg2+]o. The deoxymyoglobin was converted further to a species identified as ferrylmyoglobin by its reaction with Na2S to form ferrous sulfmyoglobin which was optically visible. This process, set into motion by acute Mg deficiency, resulted from a direct accessibility of the exogenous peroxide to the cytosolic protein. The results suggest that a pathway leading to cardiac tissue damage, induced by magnesium deficiency, is probably involved in the generation of a ferrylmyoglobin radical which could be prevented by addition of ascorbate, which is known to be a one-electron reductant of this hypervalent form of myoglobin. In further studies, we also investigated whether addition of different concentrations of ascorbic acid (AA) to the perfusate could enhance myocardial function after exposure to low [Mg2+]o perfusion. Four concentrations of AA (0.5, 1, 5, 10 mM) were tested, and the results indicate that they exert their effects in a concentration-dependent manner; 1 mM AA was the most effective dose in improving aortic output in a Mg-deficient heart. Ferrylmyoglobin formation was found to be formed considerably before intracellular release of either creatine phosphokinase or lactic dehydrogenase. These studies may have wide implications as a new mechanism by which low extracellular Mg2+ can induce myocardial injury and subsequent cardiac failure.  相似文献   

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No doubt, double and triple infection in a patient is not an uncommon phenomenon in the Old World. Consequently, the histopathological picture of the liver of Syrian golden hamsters experimentally infected with Leishmania. d. infantum on top of pre-infection with S. mansoni was studied. The results showed that the liver was markedly affected by the concomitant infection than infection with either parasite alone. The superadded Leishmania infection caused the early appearance of cell necrosis and fatty changes. The schistosomal granulomas were rounded in shape and well circumscribed. However, they were smaller in size and less in number when compared with schistosomal control. Also, there was a comparative decrease in the number of their cellular constitutions but without changing in the cell types. The schistosomal granulomas were surrounded with a rim of amastigotes laden macrophages. On the other hand, the leishmanial granulomas, were irregular in shape but comparatively increased in size and in number on the behalf of the schistosomal granulomas. Their cellular constitutions comparatively increased as well. So, it is concluded that the L.d. infantum infection on the top of S. mansoni infection suppressed the schistosomal pathological picture in the liver of hamsters.  相似文献   

6.
We have shown that 8S and U2 fractions of low molecular weight nuclear RNA lmwn RNA) have tow stable conformational states with different electrophoretic mobilities. We have shown also that fractions UIa and UIb are conformational isomers. Fractions 8S and U2 are present only in one conformational state during electrophoresis, while UI RNA is always represented by both conformations. The conformation of lmwn RNAs is dependent upon conditions of isolation of nuclei and of extraction of RNA. It may change during storage of water solution of RNA at -20 degrees. Conformational changes discovered are not the result of degradation. Only one of two stable conformations of any lmwn RNA may be physiologically active, as it is the case of 5S rRNA and tRNAS. One ought to keep this in mind while studying the functions of low molecular weight nuclear RNAs.  相似文献   

7.
The authors studied a species of Leishmania which is the causative agent of cutaneous leishmaniasis in Mato Grosso, Brazil. The parasite displays unusual characteristics which do not fit exactly into either the L. mexicana or L. brasiliensis complexes. The buoyant density DNA resembles that of the L. mexicana complex but the culture and hamster inoculation results resemble those of the L. brasiliensis complex. Further comparative studies are required to elucidate the relationship of the Mato Grosso Leishmania to the L. mexicana complex.  相似文献   

8.
OBJECTIVES: Rabeprazole is a new fast acting proton pump inhibitor that has recently been proven to be effective in the treatment of peptic ulceration and reflux esophagitis. The aim of this study was to evaluate rabeprazole in combination with antibiotics for the eradication of Helicobacter pylori (H. pylori) in patients with chronic active gastritis with or without peptic ulcer disease. METHODS: Seventy-five H. pylori-infected patients were randomized in a double-blind fashion to receive a 7-day treatment regimen consisting of: RAC, RAM, RCM, or RC (R=rabeprazole 20 mg b.d., A=amoxycillin 1 g b.d., C=clarithromycin 500 mg b.d., M=metronidazole 400 mg b.d.). Randomized patients were H. pylori-positive by gastric biopsy urease test, histology and 13C urea breath test (13C-UBT). H. pylori eradication was assessed by 13C-UBT, 4 and 8 wk after finishing treatment. Endoscopy with histology and culture for antibiotic sensitivity testing was performed pretreatment and if treatment failed. RESULTS: On an intention-to-treat analysis, treatment success was: RCM 100%, RAC 95%, RAM 90%, and RC 63%. The most common side effects were loose stools, headache, and taste disturbance, but there were no serious adverse events related to the study medication. The two patients failing RAM treatment had metronidazole-resistant strains before and after treatment. None of the pretreatment H. pylori isolates from six patients failing RC were clarithromycin resistant, but three of five successfully cultured posttreatment had developed clarithromycin resistance. CONCLUSION: Rabeprazole-based triple therapy with two antibiotics for 1 wk is safe and effective in eradicating H. pylori. Dual therapy with clarithromycin is less successful, and the majority of treatment failures develop clarithromycin resistance.  相似文献   

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OBJECTIVE: To determine if exposure to benzodiazepines during the first trimester of pregnancy increases risk of major malformations or cleft lip or palate. DESIGN: Meta-analysis. SETTING: Studies from 1966 to present. SUBJECTS: Studies were located with Medline, Embase, Reprotox, and from references of textbooks, reviews, and included articles. Included studies were original, concurrently controlled studies in any language. INTERVENTIONS: Data extraction and quality assessment were done independently and in duplicate. MAIN OUTCOME MEASURES: Maternal exposure to benzodiazepines in at least the first trimester; incidence of major malformations or oral cleft alone, measured as odds ratios and 95% confidence intervals with a random effects model. RESULTS: Of over 1400 studies reviewed, 74 were retrieved and 23 included. In the analysis of cohort studies fetal exposure to benzodiazepine was not associated with major malformations (odds ratio 0.90; 95% confidence interval 0.61 to 1. 35) or oral cleft (1.19; 0.34 to 4.15). Analysis of case-control studies showed an association between exposure to benzodiazepines and development of major malformations (3.01; 1.32 to 6.84) or oral cleft alone (1.79; 1.13 to 2.82). CONCLUSIONS: Pooled data from cohort studies showed no association between fetal exposure to benzodiazepines and the risk of major malformations or oral cleft. On the basis of pooled data from case-control studies, however, there was a significant increased risk for major malformations or oral cleft alone. Until more research is reported, level 2 ultrasonography should be used to rule out visible forms of cleft lip.  相似文献   

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By use of a standard reporting form, extensive data were gathered on 651 deaths involving psychotropic drugs and recorded with the Coroner's or Medical Examiner's Office in each of four major U.S. cities. Thirty-six per cent of these deaths were listed as "Definitely Suicide" and 44% were listed as "Non-Suicide." A comparison was made of the age, sex, race, occupational category, and type of drug involved for each of these two groups, by city. In general, the Suicide group tended to be older, from higher occupational levels, and more often female. Blacks were under-represented among the Suicides but over-represented among the Non-Suicides. Suicide deaths tended to be associated with barbiturates, analgesics, and/or sedatives, while the Non-Suicides usually died from an accidental abuse of narcotics, usually heroin. These findings tended to be similar for each city, although some inter-city differences were noted.  相似文献   

11.
The tongue of the fresh-water turtle, Geomyda trijuga, was investigated histochemically to determine the localization and nature of mucosubstances in it. The results were considered in comparison with the lingual mucosubstances of other vertebrates. A heterogenous distribution of neutral mucosubstances, sulphomucins, sialomucins and hyaluronic acid in various lingual sites was noted. The anterior half of the lingual surface was keratinized, whereas on the posterior half numerous broad papillae and three types of goblet cells were found. The lingual salivary glands were absent from the turtle tongue. The importance of lingual histology in establishing the phylogeny of vertebrates and the possible functional significance of mucosubstances in the physiology of gustation are discussed.  相似文献   

12.
This study compared the Wechsler Intelligence Scale for Children-III (WISC-III) scores of traumatized youth with posttraumatic stress disorder (PTSD) to the scores of trauma-exposed and nonexposed comparison groups without PTSD. All groups were free of additional major childhood psychiatric disorders. The PTSD group scored significantly lower than the comparison groups on verbal subtests, but not on performance subtests. The scores of the trauma-exposed PTSD negatives and nontrauma exposed controls were not significantly different. Accordingly, PTSD and not a history of trauma exposure in the absence of PTSD was associated with lower verbal IQ. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
OBJECTIVE: To evaluate psychiatric disorders and impairment in school-age and adolescent children of opiate-dependent patients. METHOD: One hundred fourteen children, aged 6 to 17 years, of 69 white methadone maintenance patients with (n = 30) and without (n = 39) major depression were evaluated for DSM-III-R diagnoses by the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Epidemiologic version and best estimate, and by measures of functioning (Children's Global Assessment Scale, Social Adjustment Inventory for Children and Adolescents, WISC, Peabody Picture Vocabulary Test), and compared with children of historical controls without substance abuse history. RESULTS: Sons of opiate addicts with major depression were at increased risk for conduct disorder and global, social, and intellectual impairment compared with sons of opiate addicts without major depression and/or sons of controls with neither drug dependence nor depression. Sons of opiate addicts without major depression differed little from controls. Daughters of opiate addicts did not differ from controls in rates of disorders but had poorer social adjustment and nonverbal intelligence. CONCLUSIONS: Children of opiate-dependent patients, particularly sons of addicts with depression, may be at risk for a developmental path toward antisocial personality and poor social and intellectual functioning. Treatment settings such as methadone maintenance might afford an opportunity for primary and secondary prevention, both through early detection of childhood disorders and treatment of parental drug dependence and psychopathology.  相似文献   

14.
Twenty-one child outpatients given Diagnostic and Statistical Manual of Mental Disorders (DSM-III) diagnoses for both conduct disorder (CD) and attention deficit disorder with hyperactivity (ADD/H) were compared with 14 children with CD but no ADD/H. Children with both CD and ADD/H exhibited more physical aggression and a greater variety and severity of antisocial behaviors despite their younger age at the time of referral than children with CD alone. The differences between groups were found to be specific to comorbidity with ADD/H and not to other codiagnoses. When considered with previous findings, these results suggest that the co-occurrence of CD and ADD/H is associated with a more serious form of conduct disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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Peculiar dorsal neurons present in the dorsal spinal cord of Trigla lucerna L. and Scorpaena porcus L. were investigated by neuroanatomical and immunohistochemical methods. These neurons were previously defined as commissural cells, but have now been identified as supramedullary neurons. The following fundamental criteria for identifying the supramedullary neurons of Teleosts are proposed: a) dorsomedial location in the spinal cord; b) large size of the soma and axon; c) immunoreactivity to gastrin/CCK-like peptides.  相似文献   

17.
The effects of heparin on the coagulation profile and on specific factor activity in canine plasma have been examined both in vivo and in vitro. The results show that the prolongation of the partial thromboplastin time of plasma produced by heparin is, at least in part, the result of the interaction of heparin with the intrinsic Factors VIII, IX and XI and the inhibition of their procoagulant activity by heparin. A significant correlation was found between the partial thromboplastin time assay and the circulating heparin activity following intravenous administration of heparin to dogs. The results confirm the suitability of the partial thromboplastin time assay for monitoring heparin therapy in the dog.  相似文献   

18.
It is known that ischemia commonly increases exogenous glucose utilization by accelerating glucose uptake and flux rates through the Embden-Meyerhof pathway. Constitutive enzymes regulate the rate of glycolysis and in turn are regulated by product inhibition and allosteric controls. The purpose of this report was to test whether mRNA abundance for select glycolytic enzymes, and glucose transport proteins, is also modified. Six intact working pig hearts with coronary flow controlled by extracorporeal perfusion were compared at the following conditions: (1) aerobic control perfusion; (2) ischemia affected by a 60% decrease in left anterior descending (LAD) coronary perfusion: (3) ischemia again affected by a 60% decrease in LAD flow followed by a 40-min interval of aerobic reflow; (4) an intermittent ischemia and reflow protocol including four cycles of similar LAD flow reductions (5 min per cycle) interspersed with 15-20 min of aerobic reperfusion; (5) a 4-day model designed to produce myocardial chronic hibernation: and (6) mild ischemia induced by a 40% decrease in LAD flow for 85 min to produce certain adaptations compatible with short-term hibernation. In each heart, mRNA abundance was measured from LAD and circumflex (LCF) perfused myocardium for hexokinase, phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase and the two glucose transporter isomers, GLUT 4 and GLUT 1. mRNA data from LAD myocardium in intervention hearts were normalized to those from LAD tissue in the control heart (LADc) and with LCF values in the same intervention hearts. Signal variance around unity in the LAD tissue, with respect to that of the LCF myocardium, in the control heart compared closely (44 and 41% in two separate runs, respectively). GLUT 1/GLUT 4 ratios in the LAD and LCF beds of this heart also agreed closely. LAD/LADc ratios were increased for hexokinase (1.69), phosphofructokinase (3.69), and glyceraldehyde-3-phosphate dehydrogenase (2.29) in the ischemia heart and for phosphofructokinase (3.90), glyceraldehyde-3-phosphate dehydrogenase (2.20), GLUT 4 (1.55) and GLUT 1 (2.20) in the ischemia/reflow heart. There was no evidence of excess signal in the intermittent ischemia/reflow, chronic hibernation, or mild ischemia hearts. Altered signal from LCF myocardium was also suggested. These data indicate that mRNA abundance for select glycolytic enzymes and transporter proteins is increased in ischemic myocardium with or without reperfusion and offers a possible mechanism for increased protein activity in settings of diminished regional coronary flow.  相似文献   

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The goals of this study were to determine the relations between different dimensions of temperament, and their interactions, with antisocial behavior (ASB) in 351 preadolescent boys with (n?=?175) or without (n?=?176) a family history of a substance use disorder (SUD) and to determine whether these relations are moderated by a family history of SUD. Participants were administered the Revised Dimensions of Temperament Survey (DOTS-R) and multiple measures of ASB. Factor analysis reduced the DOTS-R subscales into three factors: Rhythmicity, Behavioral Regulation, and Positive Affectivity. Results indicated that above and beyond the effects of age and socioeconomic status, low rhythmicity, low behavioral regulation, and low positive affectivity, as well as some of their higher order interactive effects, are important indicators of different types of ASB and, in some cases, only in boys with a family history of SUD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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