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M Elias

Publications and source records attributed to M Elias.

At least 37 records · Page 2Linked to original sources
PubMed2001

Unmanaged sexual reproduction and the dynamics of genetic diversity of a vegetatively propagated crop plant, cassava (Manihot esculenta Crantz), in a traditional farming system.

Occurrence of intervarietal or interspecific natural crosses has been reported for many crop plants in traditional farming systems, underlining the potential importance of this source of genetic exchange for the dynamics of genetic diversity of crop plants. In this study, we use microsatellite loci to investigate the role of volunteer seedlings (plants originating from unmanaged sexual reproduction) in the dynamics of genetic diversity of cassava (Manihot esculenta Crantz), a vegetatively propagated crop, in a traditional farming system in Guyana. A previous field study showed that farmers incorporate such plants into the germplasm for vegetative propagation, and that many of them are likely to be assigned by farmers to recognized varieties. Under strict vegetative propagation clonality of varieties is expected. The high proportion of polyclonal varieties observed suggests that incorporation of seedlings into the germplasm for propagation is a frequent event. The molecular variability assessed with microsatellite markers shows that there is high differentiation among heterozygous varieties, whereas populations of seedlings do not depart from the proportions expected under Hardy-Weinberg assumptions. Assignment of seedlings to a recognized variety on the basis of morphological similarity greatly increases genetic diversity within the variety. We argue that recombination and gene flow play a major role in the dynamics of genetic diversity of cassava in traditional farming systems. Documenting unmanaged sexual reproduction and its genetic consequences is a prerequisite for defining strategies of in situ conservation of crop plant genetic resources.

Alleles↗
PubMed2000

Posttraumatic akinetic-rigid syndrome resembling Parkinson's disease: a report on three patients.

We describe three patients who developed a rapidly evolving posttraumatic akinetic-rigid syndrome (ARS), the clinical manifestations of which were similar to Parkinson's disease, including response to levodopa. Despite initial imaging studies showing traumatic damage to the substantia nigra, the ARS appeared after a delay of 1-5 months after the injury. We stress the importance of magnetic resonance imaging to illustrate nigral damage in all patients in whom head trauma precedes an ARS.

Adult↗
PubMed2000

Assessment of genetic variability in a traditional cassava (Manihot esculenta Crantz) farming system, using AFLP markers.

Despite the urgent need to conserve domesticated plant genetic resources, and developing 'on farm' strategies of conservation, the impact of traditional farming practices and of their interaction with ecological factors on the structure and evolutionary dynamics of the genetic variability of crop populations has been little documented. We assessed the genetic variability of 31 varieties of cassava (M. esculenta Crantz) traditionally grown by Makushi Amerindians from Guyana, using AFLP markers. We used a sample of 38 varieties from an ex situ core collection as a reference. Accessions of wild cassava were also included. While clonality of the varieties was expected due to the vegetative propagation of cassava, 21 varieties presented intravarietal polymorphism. Among the varieties from a single site in Guyana, genetic diversity was the same as that in the accessions from the core collection. We suggest that incorporation of volunteer seedlings, produced by sexual reproduction, into the stock of varieties grown by the Makushi plays a major role in explaining both intravarietal polymorphism and the high level of genetic diversity. No correspondence was found between the structure of molecular diversity and variation observed for agronomic traits that are targets for selection by cultivators. As found in previous studies, all wild forms of cassava clustered together and separately from the cultivated varieties in a Neighbour-Joining dendrogram. These results are consistent with the hypothesis of a limited domestication event in a restricted area, followed by rapid diffusion of cultivated phenotypes and convergent evolution. Our results show that local varieties are an important source of genetic diversity, and highlight the importance of the interaction between human and ecological factors in the dynamics of this diversity.

Evolution, Molecular↗
PubMed2000

Gastropathy and NSAIDs.

Explore the source record for details and available documents.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

Cervical sympathetic and stellate ganglion blocks.

Sympathetic blocks in the cervical and upper thoracic region are commonly used techniques for a variety of diagnostic, therapeutic and prognostic purposes. Stellate ganglion block is the common nomenclature utilized, however, stellate ganglion is present in only 80% of the population, thus, either lower cervical sympathetic block or upper thoracic sympathetic block is an appropriate term. The cervical sympathetic ganglia are identified as the superior, middle, intermediate and the inferior cervical sympathetic ganglion. The superior cervical ganglia are approximately 3 to 5 cm in length and situated on the longus capitus muscle anterior to the transverse process of the second, third, and rarely the fourth cervical vertebrae; the middle cervical ganglia are the smallest of the cervical ganglia situated on the longus colli muscle, anterior to the base of the transverse process of the sixth vertebrae; and the intermediate cervical ganglia which are more consistent in position and are located on the medial side of the vertebral artery. The inferior cervical ganglia, when present, are located on the transverse process of the C7 vertebrae, whereas the first thoracic ganglia are situated in front of the neck of the first rib. In 70% to 80% of the population they are fused together forming the stellate ganglion. Stellate ganglion block or lower cervical sympathetic block has been advocated for both diagnostic, therapeutic, and prognostic purposes for a variety of conditions. Even though multiple techniques are advocated in performing this block, fluoroscopically guided sympathetic blocks are more appropriate. Complications of stellate ganglion block include complications related to the technique, infection, and pharmacological complications related to the drugs utilized. Cervical sympathetic or stellate ganglion block is a very commonly performed procedure. If performed correctly, this can provide good therapeutic, prognostic, and diagnostic values.

Journal Article↗
PubMed1999

Food but not a chemically defined diet interferes with maintenance of intragastric pH at a predefined level using continuous pH-stat-adjusted intravenous infusion of ranitidine in healthy volunteers.

Eight healthy volunteers were used to determine the influence of a normal diet (food) versus an isocaloric chemically defined diet (CDD) on the dose of ranitidine infused continuously over 12 hr, required to maintain the intragastric pH > or = 5 or above. The dose of ranitidine used was adjusted by the pH-stat instrument, Gastrojet, and a target pH of 5.0 was selected. The average ranitidine dose was 43.5 mg for food, 28.3 mg for CDD, and 25.7 mg for fasting. Despite the higher dose of ranitidine used with food, the control of pH was lower than the desired and preset value of pH > or = 5: the average mean pH was 3.99 for food, 5.11 for CDD, and 5.75 for fasting. The percentage of time of pH > or = 5 was 32.0% for food, 73.7% for CDD, and 80.1% for fasting. Thus, when persons are fed a normal diet there is a need for higher doses of ranitidine to maintain the gastric pH > or = 5.0. Even with frequent monitoring of intragastric pH with the Gastrojet, there is much greater variability in pH control with food than with CDD or fasting, and the preset and desired pH level was not achieved. This difficulty in achieving desired end points of pH control when switching from a fasting to a fed state needs to be considered when intravenous ranitidine is used to obtain strict control of intragastric pH.

Adult↗
PubMed1999

[Cryptococcal meningitis following cryptococcal pneumonia in an immunocompetent].

Cryptococcal meningitis (CM) is common in the immunocompromised (especially due to AIDS), but also occurs in immunocompetent subjects. CM can complicate cryptococcal pneumonia (CP) not only in the immunocompromised but also in the immunocompetent. We describe a healthy 26-year-old man who developed a prolonged lung infection. Diagnosis of cryptococcal pneumonia was established from bronchoscopic washings. He recovered spontaneously, so no antifungal treatment was given. 4 months later he was admitted with cryptococcal meningitis and was treated successfully with amphotericin B. An extensive immunologic study revealed no abnormalities. Since CM can complicate cryptococcal pneumonia, it is recommended that patients with CP be followed, even if recovery is apparently complete.

Adult↗
PubMed1998

Familial pattern of infection with hepatitis B virus among immigrating Ethiopian Jews in Israel.

Seventy-eight families (506 members) of recently immigrating Ethiopian Jews to Israel, were tested for the presence of HBV serological markers to evaluate the intrafamilial horizontal transmission of the virus. Eighty-four members (16.6%) were carriers and 20.2% were HBeAg positive, the overall infection rate was 67.8%. In 40 families (51.3%) at least one family member was HBsAG positive, and in 19 families (24.4%) two or more family members were HBsAg positive. Thirty-six carriers (42.8%) were children under the age of 10, by one year of age 30% have contracted the virus, and by the age of 5 and 10 years 43.5% and 57.1% have had serological markers for past HBV infection, respectively. Our data correlate with other studies regarding the importance of horizontal spread of HBV among Sub-Saharan Africans.

Adolescent↗
PubMed1998

Ropivacaine-induced seizure after extradural anaesthesia.

Ropivacaine is considered safer than bupivacaine, on the basis of experimental and human data that indicate a lower systemic toxicity. Here we report the occurrence of a single seizure after i.v. administration of ropivacaine 120 mg intended for extradural block in a patient having postpartum, tubal ligation. The only prodromal symptom was nervousness, and the only cardiovascular manifestation was sinus tachycardia. Systemic toxicity, although less than that expected with bupivacaine, can occur with ropivacaine.

Adult↗
PubMed1998

Delayed interval delivery in a quintuplet pregnancy.

We present a case report of delayed delivery of a quintuplet pregnancy. The pregnancy resulted from intrauterine insemination following hormonal treatment. This case may represent the first report of quintuplets delivered using the technique of delayed interval delivery. Three separate spontaneous labours and one Caesarean section for two fetuses took place between the 24th and 32nd weeks of pregnancy. The delay between the first and the last delivery was 61 days. Only a boy, born fourth, survived.

Adult↗