Ultrasound curriculum taught by first-year medical students: A four-year experience in Tanzania / 世界急诊医学杂志（英文）

BACKGROUND:Diagnostic imaging is an integral aspect of care that is often insufficient, if not altogether absent, in rural and remote regions of low to middle income countries (LMICs) such as Tanzania. The introduction of ultrasound can significantly impact treatment in these countries due to its portability, low cost, safety, and usefulness in various medical assessments. This study reviews the implementation of a four-week ultrasound course administered annually from 2013–2016 in a healthcare professional school in Mwanza, Tanzania by first-year allopathic US medical students. METHODS:Participants (n=582, over 4 years) were recruited from the Tandabui Institute of Health Sciences and Technology to take the ultrasound course. Subjects were predominantly clinical officer students, but other participants included other healthcare professional students, practicing healthcare professionals, and school employees. Data collected includes pre-course examination scores, post-course examination scores, course quiz scores, demographic surveys, and post-course feedback surveys. Data was analyzed using two-tailed t-tests and the single factor analysis of variance (ANOVA). RESULTS:For all participants who completed both the pre- and post-course examinations (n=229, 39.1％ of the total recruited), there was a significant mean improvement in their ultrasound knowledge of 42.5％, P<0.01. CONCLUSION:Our data suggests that trained first-year medical students can effectively teach a point of care ultrasound course to healthcare professional students within four weeks in Tanzania. Future investigation into the level of long-term knowledge retention, impact of ultrasound training on knowledge of human anatomy and diagnostic capabilities, and how expansion of an ultrasound curriculum has impacted access to care in rural Tanzania is warranted.

White pine weevil (Pissodes strobi) biological performance is unaffected by the jasmonic acid or wound-induced defense response in Norway spruce (Picea abies).

In eastern Canada, the white pine weevil (Pissodes strobi Peck) is a pest of several native pine and spruce species and of the introduced species, Norway spruce (Picea abies Karst). We evaluated the feeding activities, oviposition and rate of adult emergence of white pine weevil on field-grown Norway spruce subjected to jasmonic acid or wounding pretreatments. We also monitored the host-plant reaction to white pine weevil attack, jasmonic acid and wounding treatments by quantifying several mono- and sesquiterpenes in bark and characterizing some molecular aspects of the terpenoid response. Two cDNA sequences were identified that had a high percentage of identity with genes encoding monoterpene or sesquiterpene synthases. Both putative terpene synthase genes showed distinctive profiles in Norway spruce bark and needles following all treatments. Although the Norway spruce trees showed different physiological responses to mechanical wounding and white pine weevil attack, transcript activity of the gene encoding terpenoid synthase and consequent accumulation of terpenoid resin did not significantly affect the weevils' feeding activities, oviposition or rate of adult emergence.

Regeneration of phenotypically normal English elm (Ulmus procera) plantlets following transformation with an Agrobacterium tumefaciens binary vector.

A transformation system was developed for English elm (Ulmus procera Salisbury) using Agrobacterium tumefaciens C58 pMP90 p35SGUS/INTRON, allowing for the transfer of foreign genes and regeneration of phenotypically normal elm plantlets. The PCR analysis indicated that both nptII and uidA genes were stably inserted in the plant genome. beta-Glucuronidase histochemical and fluorimetric assays revealed expression of the uidA gene in the shoots, leaves, stems and roots of regenerated transgenic plants. The DNA-DNA hybridizations confirmed the presence of the uidA gene in regenerant plants. Factors influencing successful transformation and regeneration of elms included: identifying gene-transfer-proficient Agrobacterium strains for use with elms; developing an infection protocol allowing T-DNA transfer while retaining the ability to remove inciting bacteria; and identifying selection conditions to eliminate non-transformed material and choice of regeneration medium to allow shoot production. The potential utility of an effective elm transformation and regeneration system in the control of Dutch elm disease is discussed.

Design and use of synthetic oligonucleotide probes in the cloning of delta-endotoxin genes from Bacillus thuringiensis.

A detailed protocol is described for the design and use of synthetic oligonucleotide probes for screening DNA libraries from Bacillus thuringiensis var. kurstaki (strain HD191) for copies of the gene (tox) encoding the insecticidal delta-endotoxin. Two homologous tox genes were identified in this organism; one of these was located on a 75-kb plasmid and the other on a second large plasmid or the bacterial chromosome. A tox gene was isolated as a 6.5-kb HindIII fragment of B. thuringiensis plasmid DNA.

Stimulation of ethylene production and gas-space (aerenchyma) formation in adventitious roots of Zea mays L. by small partial pressures of oxygen.

Adventitious roots of two to four-weekold intact plants of Zea mays L. (cv. LG11) were shorter but less dense after extending into stagnant, non-aerated nutrient solution than into solution continuously aerated with air. Dissolved oxygen in the non-aerated solutions decreased from 21 kPa to 3-9 kPa within 24 h. When oxygen partial pressures similar to those found in non-aerated solutions (3, 5 and 12 kPa) were applied for 7 d to root systems growing in vigorously bubbled solutions, the volume of gas-space in the cortex (aerenchyma) was increased several fold. This stimulation of aerenchyma was associated with faster ethylene production by 45-mm-long apical root segments. When ethylene production by roots exposed to 5 kPa oxygen was inhibited by aminoethoxyvinylglycine (AVG) dissolved in the nutrient solution, aerenchyma formation was also retarded. The effect of AVG was reversible by concomitant applications of 1-aminocyclopropane-1-carboxylic acid, an immediate precursor of ethylene. Addition of silver nitrate, an inhibitor of ethylene action, to the nutrient solution also prevented the development of aerenchyma in roots given 5 kPa oxygen. Treating roots with only 1 kPa oxygen stimulated ethylene production but failed to promote gas-space formation. These severely oxygen-deficient roots seemed insensitive to the ethylene produced since a supplement of exogeneous ethylene that promoted aerenchyma development in nutrient solution aerated with air (21 kPa oxygen) failed to do so in nutrient solution supplied with 1 kPa oxygen. Both ethylene production and aerenchyma formation were almost completely halted when roots were exposed to nutrient solutions devoid of oxygen. Thus both processes require oxygen and are stimulated by oxygen-deficient surroundings in the 3-to 12-kPa range of oxygen partial pressures when compared with rates observed in air (21 kPa oxygen).