Effects of the sap of the common oleander Nerium indicum (Apocyanaceae) on male fertility and spermatogenesis in the oriental tobacco budworm Helicoverpa assulta (Lepidoptera, Noctuidae). (1/30)

We investigated the effects of sap of the common oleander Nerium indicum (Apocyanaceae) on male fertility and spermatogenesis in the oriental tobacco budworm Helicoverpa assulta. We found that continuous feeding of oleander sap during the larval period significantly affects fertility in males but not in females. This effect was also induced by direct injection of oleander sap into the hemocoel of 2-day-old pupae. Histological analyses of developing testes following oleander injection revealed a developmental delay and progressively more severe morphological abnormalities in the later stages of development. The effects of oleander sap on spermatogenesis in H. assulta were associated with greatly reduced levels of the two major polyamines, spermidine and spermine, in testis compared with saline-injected controls. In contrast, levels of putrescine, which is a precursor of both spermidine and spermine, and the activities of the enzymes ornithine decarboxylase and arginine decarboxylase, which are involved in the biosynthesis of putrescine, were initially elevated following oleander injection, but subsequently failed to undergo the induction that normally occurs during late pupal development. The effects of oleander sap on spermidine and spermine levels could be the result of direct inhibition by chemical constituents of the oleander sap of one of the enzymes used in common in the conversions of putrescine to spermidine and spermidine to spermine; alternatively, these effects on polyamine metabolism could be secondary to the disruption of a more fundamental process in the developmental program guiding spermatogenesis in H. assulta.  (+info)

Simultaneous determination of cardenolides by sonic spray ionization liquid chromatography-ion trap mass spectrometry--a fatal case of oleander poisoning. (2/30)

Simultaneous determination of oleandrin and its three related compounds, desacetyloleandrin, oleandrigenin, and gitoxigenin in blood by using liquid chromatography-three-dimensional quadrupole mass spectrometry (LC-3DQMS) system equipped with sonic spray ionization (SSI) interface was conducted. This analyzing method was suitable for all of these compounds except gitoxigenin. The limits of detection of oleandrigenin and desacetyloleandrin from blood were 2 ng/mL and that of oleandrin was 3 ng/mL. The calibration curves for oleandrin, desacetyloleandrin, and oleandrigenin were linear in the range of 5-100 ng/mL. The coefficients of variation of oleandrin, desacetyloleandrin, and oleandrigenin in the blood were satisfactory ranging from 1.6% to 4.1%. This analysis method was applied to a fatal case of oleander poisoning. As a result of liquid chromatography-mass spectrometry (LC-MS) analysis, oleandrin was detected in heart blood and cerebrospinal fluid. Desacetyloleandrin, oleandrigenin, and gitoxigenin were not detected. In order to make identification of oleandrin reliable, LC-MS-MS analysis was performed. The concentrations of oleandrin found in the heart blood and cerebrospinal fluid were 9.8 and 10.1 ng/mL, respectively.  (+info)

Whole-genome comparative analysis of three phytopathogenic Xylella fastidiosa strains. (3/30)

Xylella fastidiosa (Xf) causes wilt disease in plants and is responsible for major economic and crop losses globally. Owing to the public importance of this phytopathogen we embarked on a comparative analysis of the complete genome of Xf pv citrus and the partial genomes of two recently sequenced strains of this species: Xf pv almond and Xf pv oleander, which cause leaf scorch in almond and oleander plants, respectively. We report a reanalysis of the previously sequenced Xf 9a5c (CVC, citrus) strain and the two "gapped" Xf genomes revealing ORFs encoding critical functions in pathogenicity and conjugative transfer. Second, a detailed whole-genome functional comparison was based on the three sequenced Xf strains, identifying the unique genes present in each strain, in addition to those shared between strains. Third, an "in silico" cellular reconstruction of these organisms was made, based on a comparison of their core functional subsystems that led to a characterization of their conjugative transfer machinery, identification of potential differences in their adhesion mechanisms, and highlighting of the absence of a classical quorum-sensing mechanism. This study demonstrates the effectiveness of comparative analysis strategies in the interpretation of genomes that are closely related.  (+info)

The cardiotonic effect of the crude ethanolic extract of Nerium oleander in the isolated guinea pig hearts. (4/30)

Cardiovascular diseases are increasingly becoming one of the leading diseases causing morbidity and mortality in Uganda. Ethnographic evidence suggests that these diseases are often first managed by indigenous and related herbs before patients are referred for allopathic forms of management. One such herb of interest is Nerium oleander. Therefore the crude ethanolic extracts of the dried leaves of this herb were tested against the following parameters in the isolated guinea pig hearts: force of contraction, heart rate and cardiac flow. The extracts brought about dose-dependent increases in all these parameters from their baseline readings. Compared with graded doses of digoxin the effects closely mirrored the activities in a dose dependent manner. At the mechanism of action level, it would appear the extract works in the same as digoxin since their dose-contraction-response curves are parallel. This finding would tend to provide a strong rationale for the herb's traditional use in cardiovascular illness.  (+info)

Multilocus simple sequence repeat markers for differentiating strains and evaluating genetic diversity of Xylella fastidiosa. (5/30)

A genome-wide search was performed to identify simple sequence repeat (SSR) loci among the available sequence databases from four strains of Xylella fastidiosa (strains causing Pierce's disease, citrus variegated chlorosis, almond leaf scorch, and oleander leaf scorch). Thirty-four SSR loci were selected for SSR primer design and were validated in PCR experiments. These multilocus SSR primers, distributed across the X. fastidiosa genome, clearly differentiated and clustered X. fastidiosa strains collected from grape, almond, citrus, and oleander. They are well suited for differentiating strains and studying X. fastidiosa epidemiology and population genetics.  (+info)

Epidemiology of intentional self-poisoning in rural Sri Lanka. (6/30)

We investigated the epidemiology of intentional self-poisoning in rural Sri Lanka by prospectively recording 2189 admissions to two secondary hospitals. Many patients were young (median age 25 years), male (57%) and used pesticides (49%). Of the 198 who died,156 were men (case fatality 12.4%) and 42 were women (4.5%). Over half of female deaths were in those under 25 years old; male deaths were spread more evenly across age groups. Oleander and paraquat caused 74% of deaths in people under 25 years old; thereafter organophosphorous pesticides caused many deaths. Although the age pattern of self-poisoning was similar to that of industrialised countries, case fatality was more than 15 times higher and the pattern of fatal self-poisoning different.  (+info)

Physical vulnerability and fatal self-harm in the elderly. (7/30)

Although the high rate of suicide in elderly people is conventionally explained as being due to greater intent to die, we have noted elderly Sri Lankans dying after relatively mild poisoning. Using data from cases of yellow oleander poisoning, we investigated the effect of age on outcome in 1697 patients, controlling for gender and amount ingested. In fully adjusted models, people over 64 years old were 13.8 (95% CI 3.6-53.0) times more likely to die than those less than 25 years old. The high number of suicides in elderly people globally is likely to be due, in part, to the difficulty they face in surviving the effects of both the poisoning and its treatment.  (+info)

Unexpectedly dangerous escargot stew: oleandrin poisoning through the alimentary chain. (8/30)

A female, aged 43 and a male, aged 66, experienced gastrointestinal and cardiovascular symptoms after a meal including snail stew. Twelve hours after the ingestion, they presented with nausea, vomiting, diarrhea, and cardiovascular symptoms typical of acute toxic digoxin ingestion and were hospitalized. The man's electrocardiogram was altered, and the woman's was normal. Serum digoxin levels, measured on a Roche COBAS Integra 800 with the Roche On-Line Digoxin reagent, were 1.14 and 1.00 nmol/L, respectively. Potassium levels were normal in both patients. The serum digoxin concentration decreased on the second day, and symptoms resolved on the third day with patients fully recovered (i.e., reversion to a normal sinus rhythm). Cardiac-glycoside-like intoxication symptoms follow the ingestion of leaves or flowers of Nerium oleander. The consumed snails were suspected to be responsible for the intoxication. In the homogenized snail tissue, the concentration expressed in digoxin equivalents was 0.282 nmol/g. The presence of oleandrin and oleandrigenin in the snails was confirmed by liquid chromatography-tandem mass spectrometry analysis, which was performed on a ionic-trap Finnigan LXQ instrument using an electrospray ionization interface. High-pressure liquid chromatographic separation was performed on a C18 column with a gradient of methanol/water. An extract of oleander leaves was used as reference.  (+info)