Third degree atrioventricular block following non-penetrating chest trauma in a dog

A two-year-old mixed breed dog was referred to the University of Florida Veterinary Medical Teaching Hospital for the management of post traumatic ventricular arrhythmias. Electrocardiography revealed third degree atrioventricular (AV) block. An echocardiogram demonstrated an echogenic, pedunculated mass arising from the caudoventral aspect of the atrial septum. The mass was believed to represent a haematoma or a thrombus associated with trauma to this region of the atrial septum. The patient was managed conservatively; third degree AV block was still pre- sent five days after trauma. The owner of the dog refused specific therapy of the arrhythmia. The patient was discharged and, unfortunately, lost to follow-up. Third degree AV block has not previously been reported following accidental, blunt thoracic trauma in the dog.     

Micro-propagation of strawberry plants in vitro — Effect of growth regulators on incidence of multi-apex abnormality

A morphological abnormality occurring in micro-propagated strawberry plants is described and illustrated. The condition is recognised in established micro-propagated plants by an abnormal phyllotaxy which results typically in 2 or more young leaves emerging together rather than singly and by an excessive number of small branch crowns being produced. Dissection shows that the abnormality originates at the apex and is manifest as a linear (or less often as a circular) arrangement of multiple apices. Such multi-apexing plants “bud-off” normal single-apexed crowns from time to time but the abnormality can persist in the main shoot for 2 years (the limit of our observations). The multi-apexing differs fundamentally from clusters of single apices which, when removed from culture and separated, give rise to normal single-crowned plants.Similarities between the multi-apexing condition and fasciation in other plant species are discussed. Changes in growth regulator constituents of the culture media are shown to control the incidence of multi-apexing. In the presence of indole-3-butyric acid (IBA), higher 6-benzyl-aminopurine (BA) concentration increases the frequency, while adding gibberellin (GA₃) decreases the incidence of affected plantlets. The frequency of abnormality varies greatly between different cultivars.It is suggested that conditions favouring greater proliferation rates in culture may also favour multi-apexing. Results indicate that multi-apexing can be avoided by using appropriate concentrations of growth regulators in culture media which will concomitantly maintain a good proliferation rate.     

Cardiac Biomarkers in Hyperthyroid Cats

Background

Hyperthyroidism has substantial effects on the circulatory system. The cardiac biomarkers NT‐proBNP and troponin I (cTNI) have proven useful in identifying cats with myocardial disease but have not been extensively investigated in hyperthyroidism.

Hypothesis

Plasma NT‐proBNP and cTNI concentrations are higher in cats with primary myocardial disease than in cats with hyperthyroidism and higher in cats with hyperthyroidism than in healthy control cats.

Animals

Twenty‐three hyperthyroid cats, 17 cats with subclinical hypertrophic cardiomyopathy (HCM), and 19 euthyroid, normotensive healthy cats ≥8 years of age. Fourteen of the hyperthyroid cats were re‐evaluated 3 months after administration of radioiodine (¹³¹I).

Methods

Complete history, physical examination, complete blood count, serum biochemistries, urinalysis, blood pressure measurement, serum T4 concentration, plasma concentrations of NT‐proBNP and cTNI, and echocardiogram were obtained prospectively from each cat.

Results

Hyperthyroid cats and cats with HCM had plasma NT‐proBNP and cTNI concentrations that were significantly higher than those of healthy cats, but there was no significant difference between hyperthyroid cats and cats with HCM with respect to the concentration of either biomarker. In hyperthyroid cats that were re‐evaluated 3 months after ¹³¹I treatment, plasma NT‐proBNP and cTNI concentrations as well as ventricular wall thickness had decreased significantly.

Conclusions and Clinical Importance

Although there may be a role for NT‐proBNP in monitoring the cardiac response to treatment of hyperthyroidism, neither NT‐proBNP nor cTNI distinguish hypertrophy associated with hyperthyroidism from primary HCM. Therefore, the thyroid status of older cats should be ascertained before interpreting NT‐proBNP and cTNI concentrations.     

Gibberellic acid: a growth factor in the unicellular alga Gymnodinium breve

Gibberellic acid stimulates growth in the unicellular alga Gymnodinium breve (dinoflagellate). The maximum effect was obtained with 10(-7) molar gibberellic acid, whereas concentrations greater than 5 x 10(-7) mole per liter were inhibitory. The effect of the compound is observed as a marked shortening of the lag period, which is normally 6 to 8 days after innoculation.     

Inductive interactions between human dermis and chick chorionic epithelium

In a study of specificity in mesenchymal-epithelial interactions, human embryonic dermis has been recombined with chick chorionic epithelium and cultured for 7 days on a host chick chorioallantoic membrane. Dermis from the sole of the foot or palm of the hand induces chick chorionic epithelium to form an epidermis that resembles chick rather than human epidermis. Chick epithelium, though it has the capacity to respond to a human dermal stimulus, is limited to forming chick-type tissue. The human dermis was modified in its turn by culture in combination with chick epithelium.     

Principles for measurement of chemical exposure based on recognition-driven anchoring transitions in liquid crystals

The competitive binding of a molecule forming a liquid crystal and a targeted analyte to a common molecular receptor presented at a solid surface possessing nanometer-scale topography is used to trigger an easily visualized surface-driven change in the orientation of a micrometer-thick film of liquid crystal. Diffusion of the targeted analyte from atmosphere to surface-immobilized receptor across the micrometer-thick film of liquid crystal is fast (on the order of seconds), and the competitive interaction of the targeted analyte and liquid crystal with the receptor provides a high level of tolerance to nontargeted species (water, ethanol, acetone, and hexanes). Systems that provide parts-per-billion (by volume) sensitivity to either organoamine or organophosphorus compounds are demonstrated, and their use for imaging of spatial gradients in concentration is reported. This approach does not require complex instrumentation and could provide the basis of wearable personalized sensors for measurement of real-time and cumulative exposure to environmental agents.