Using molecular markers to assess the effect of introgression on quantitative attributes of common bean in the Andean gene pool.

Progress in bean breeding programs requires the exploitation of genetic variation that is present among races or through introgression across gene pools of Phaseolus vulgaris L. Of the two major common bean gene pools, the Andean gene pool seems to have a narrow genetic base, with about 10% of the accessions in the CIAT core collection presenting evidence of introgression. The objective of this study was to quantify the degree of spontaneous introgression in a sample of common bean landraces from the Andean gene pool. The effects of introgression on morphological, economic and nutritional attributes were also investigated. Homogeneity analysis was performed on molecular marker data from 426 Andean-type accessions from the primary centres of origin of the CIAT common bean core collection and two check varieties. Quantitative attribute diversity for 15 traits was studied based on the groups found from the cluster analysis of marker prevalence indices computed for each accession. The two-group summary consisted of one group of 58 accessions (14%) with low prevalence indices and another group of 370 accessions (86%) with high prevalence indices. The smaller group occupied the outlying area of points displayed from homogeneity analysis, yet their geographic origin was widely distributed over the Andean region. This group was regarded as introgressed, since its accessions displayed traits that are associated with the Middle American gene pool: high resistance to Andean disease isolates but low resistance to Middle American disease isolates, low seed weight and high scores for all nutrient elements. Genotypes generated by spontaneous introgression can be helpful for breeders to overcome the difficulties in transferring traits between gene pools.

Association between seed coat polyphenolics (tannins) and disease resistance in common bean.

Common beans (Phaseolus vulgaris L) contain a number of antinutritional factors such as condensed tannins. Reducing tannin concentration might contribute to improving the nutritional quality of common bean. But polyphenolics are involved in resistance to diseases and pests, and reducing tannin concentration may have a negative effect on plant resistance. Furthermore, the effects of tannin on disease resistance in different gene pools or in different seed colors are not defined. To investigate these effects, 790 accessions from a common bean core collection were investigated. Data were subjected to independent sample t-tests, and the calculation of correlation coefficients. The mean coat extracts of black and red bean classes were highest (with 0.129 g/g and 0.124 g/g of seed coat, respectively). Among the gene pools, the coat extract was greater in the Middle American gene pool (0.129 g/g) than in the Andean gene pool (0.108 g/g). Coat extract in the Andean gene pool was positively correlated with susceptibility to Middle American isolates of anthracnose and to common bacterial blight, but negatively correlated with susceptibility to Andean isolates of angular leaf spot and to empoasca. Only empoasca damage showed negative correlation with coat extract in the Middle American gene pool. However within gene pools, the coat extracts of different seed classes varied in correlations with reactions to disease and pest infestations. Significant correlations were particularly associated with the black seed class in both gene pools. The relationships between coat extract and disease reactions are complex. A better understanding will help breeders to select germplasm with improved nutritional quality without adversely affecting disease resistance.

Management of the postoperative anesthetic period.

While anesthetic methods and drugs have undergone many changes in the last 100 years, the incidence of complications during the postanesthesia recovery period remains constant. Prompt recognition and treatment of the complications observed during the postoperative period decreases unexpected hospital admissions and the undesirable mortality or morbidity associated with surgery and anesthesia.

Possible theophylline toxicity during anesthesia.

Asthmatic patients who undergo outpatient anesthesia are typically prescribed one or more drugs for treatment. Some of these agents have narrow therapeutic ranges and are associated with potentially serious adverse reactions, toxic effects, or drug interactions. Various clinical signs of toxicity may be first uncovered during routine monitoring of an office anesthetic. The case reported here demonstrates the need for proper understanding of the asthmatic patient's medical history and an appreciation for the medications used to control the disease. A sudden cardiovascular event possibly related to drug toxicity is witnessed and treated in an asthmatic patient during intravenous sedation. A possible drug interaction with a non-asthmatic medication taken concomitantly by the patient is implicated and discussed. In addition to the case report, the broad classification of drugs employed for bronchial asthma and their effects is reviewed.

Ketorolac tromethamine: an oral/injectable nonsteroidal anti-inflammatory for postoperative pain control.

Ketorolac tromethamine is a new injectable/oral nonsteroidal anti-inflammatory analgesic with no apparent opiate receptor activity that has been administered alone and in combination with other opiate analgesics for the treatment of postoperative pain. The drug has shown promise in analgesic comparisons with morphine sulfate; it lacks the effects of respiratory depression and nausea and vomiting usually associated with narcotic agents. Intramuscular ketorolac may be particularly useful with those patients who have respiratory disease and patients being dismissed following short ambulatory or private-office anesthetic procedures.

Submental administration of succinylcholine in children.

During inhalation induction of the pediatric patient, laryngospasm can develop before intravenous access has been established. The intramuscular administration of succinylcholine is commonly used in such instances. This study was designed to determine if the injection of succinylcholine by an extraoral submental approach would be an acceptable method of terminating laryngospasm when compared to conventional intramuscular sites. Following induction with halothane and nitrous oxide in oxygen, a total of fifteen ASA 1 children were given 3.0 mg/kg intramuscular succinylcholine either intralingually by a submental approach, or using the upper leg musculature in order to electromyographically measure the time to maximum (or 90 percent depression from baseline) twitch depression. The intralingual submental injection had a mean twitch depression of 265 +/- 62.5 seconds compared to the quadriceps femoris at 295 +/- 42.6 seconds. A group with digital massage of the intralingual injection site produced a mean depression time of 133 +/- 11.9 seconds and was also the only group providing 100% success rate in reaching the desired twitch depression level. This may suggest that the operator should consider digital massage to produce a more predictable and desirable result.