Reflections on what makes a good teacher

Nine 3-week-old conventional pigs were inoculated intranasally with a Korean isolate of porcine respiratory coronavirus (PRCV). Three 3-week-old conventional pigs were kept as noninoculated controls. Three inoculated and one control pig were euthanatized at 5, 10, and 15 days postinoculation (DPI), respectively. All nine inoculated pigs developed respiratory disease. Interstitial pneumonia characterized by mononuclear inflammatory cell infiltration into alveolar septa were seen microscopically in all nine PRCV-infected pigs. Histopathologic changes were severe at DPI, modest at 10 DPI, and almost resolved at 15 DPI. PRCV antigen was not detected in bronchial and bronchiolar epithelium but was detected in interstitial macrophages in the lungs. This Korean isolate of PRCV appeared to replicate primarily within alveolar macrophages in the respiratory system of the pig.     

Membrane permeability characteristics of metaphase II mouse oocytes at various temperatures in the presence of Me2SO

Real bone tumors are rarely encountered in the daily routine of radiological practice. Therefore, for a general radiologist there is no need for a specialist knowledge on this field. However, he should be able to distinguish benign from malignant lesions in order to avoid unnecessary biopsies. A systematic approach towards osteolytic lesions, e.g. according to the classification of Lodwick, is mandatory. CT and MRI are indicated to clear up the anatomy in areas of superposition artefacts in conventional radiology and to determine the inner structure of a lesion, e.g. fatty tissue, liquid/solid. This paper highlights the advantages and disadvantages and the cost-effective use of the imaging modalities including scintigraphy in the diagnosis of bone tumors and tumor-like lesions. Guidelines for the management of bony lesions will be given in detail. The option and necessity for a specialist second opinion is emphasized.     

Dynamic Accumulation of Volatile Compounds Between Olive Pulps and Stones and Its Relation with the Fatty Acids Content During the Oil Extraction Process of Ouslati and Chemlali Olive Fruits

The characterization of both volatiles and fatty acids of Tunisian olive varieties (Ouslati and Chemlali) is achieved in order to understand their correlation with the aroma accumulation via the lipoxygenase (LOX) pathway. The main identified volatiles in both crushed pulps and crushed stones are hexanal, E‐(2)‐hexenal, (Z)‐3‐hexen‐1‐ol, 1‐hexanol, and hexyl acetate. With regard to their fatty acid composition, results show that both de‐stoned (DOO) and conventional (COO) olive oils contain mainly unsaturated fatty acids. The results also show that oleic acid (C18:1) is the main fatty acid in both DOO and COO. Meanwhile, linoleic acid (C18:2) is present in a relatively higher percentage (5.2% and 19.8%, respectively, for Ouslati and Chemlali DOI) than linolenic fatty acid (C18:3) (<2%). The analysis of volatiles shows that more than 80% of total LOX‐compounds from both crushed pulps and crushed stones have linolenic acid as synthesis precursor despite its lower level (2%). Moreover, the contribution of olive parts in generating aroma is much higher in crushed pulps (more than 80%) than in crushed stones, which explains the fact that DOO, extracted from crushed pulps, contains the dominant amount of volatiles. Therefore, the obtained results promote both the consumption and the marketing of DOO. Practical Applications: The aroma and the organoleptic properties of olive oil are strictly correlated with both the olives quality and the extraction techniques used. Many technologies are developed to extract olive oil with highest quality. De‐stoned olive oil extraction process is one of these technical procedures. In the present work, the characterization of volatiles in pulp and stone separately provides important information about the contribution of olive constitutive parts on the accumulation of olive oil aroma during the oil extraction process.     

Effect of lactose on cross‐linking of milk proteins during heat treatments

The major types of nondisulphide cross‐linking which cause milk protein aggregation were investigated in milk, with and without lactose, heated at 95 °C for up to 8 h. Compared with the milk containing no lactose, the milk containing lactose showed a smaller increase in pH, a larger increase in pH 4.6 soluble nitrogen, much smaller increase in lysinoalanine (LAL) and a much higher percentage of cross‐linked proteins. It was concluded that cross‐linking in milk products containing lactose occurs mainly via Maillard reaction products, and in milk products with no lactose, it occurs mainly via isopeptide linkages such as in LAL.     

Dopamine decreases the excitability of layer V pyramidal cells in the rat prefrontal cortex

In both primates and rodents, the prefrontal cortex (PFC) is highly innervated by dopaminergic fibers originating from the ventral tegmental area, and activation of this mesocortical dopaminergic system decreases spontaneous and evoked activity in the PFC in vivo. We have examined the effects of dopamine (DA), over a range of concentrations, on the passive and active membrane properties of layer V pyramidal cells from the rat medial PFC (mPFC). Whole-cell and perforated-patch recordings were made from neurons in rat mPFC. As a measure of cell excitability, trains of action potentials were evoked with 1-sec-long depolarizing current steps. Bath application of DA (0.05-30 microM) produced a reversible decrease in the number of action potentials evoked by a given current step. In addition, DA reversibly decreased the input resistance (RN) of these cells. In a subset of experiments, a transient increase in excitability was observed after the washout of DA. Control experiments suggest that these results are not attributable to changes in spontaneous synaptic activity, age-dependent processes, or strain-specific differences in dopaminergic innervation and physiology. Pharmacological analyses, using D1 agonists (SKF 38393 and SKF 81297), a D1 antagonist (SCH 23390), a D2 receptor agonist (quinpirole), and a D2 antagonist (sulpiride) suggest that decreases in spiking and RN are mediated by D2 receptor activation. Together, these results demonstrate that DA, over a range of concentrations, has an inhibitory effect on layer V pyramidal neurons in the rat mPFC, possibly through D2 receptor activation.     

Segregation analysis of NIDDM in Caucasian families

Non-insulin-dependent diabetes mellitus (NIDDM) has a substantial genetic component, but the mode of inheritance and the molecular basis are unknown. We have undertaken segregation analysis of NIDDM after studying 247 subjects in 59 Caucasian nuclear pedigrees ascertained without regard to family history of the disorder. The analyses were performed using POINTER and COMDS, which are computer programs which apply statistical models to the data. POINTER analysis was performed defining the phenotype as a presence or absence of hyperglycaemia. Among single locus hypothesis, the analyses rejected a recessive model and favoured a dominant model, but could not statistically show that this fitted better than a mixed model (a single locus against a polygenic background) or a polygenic model. COMDS analysis assumed a continuum of hyperglycaemia from normality to NIDDM, classified family members into a series of diathesis classes with increasing plasma glucose levels and compared the distribution with that found by screening the normal population. This analysis improved the likelihood of a dominant single locus model and suggested a gene frequency of 7.4%. It raised the possibility of a second locus, but cannot identify or exclude a polygenic model. In conclusion, two types of segregation analyses rejected a recessive model and favoured a dominant model of inheritance, although they could not statistically show that this fitted better than the polygenic model. The results raised the possibility of a common dominant gene with incomplete penetrance, but genetic analysis of NIDDM needs to take into account the likelihood of polygenic inheritance with genetic heterogeneity.     

Organometallic flavonoid derivatives as spectroscopic probes

Derivatives of naringenin have been synthesized with organometalcarbonyl reporting groups for IR spectroscopy attached at C-2, C-3', or C-6, and the products have been tested for the induction of nod gene expression using a Rhizobium leguminosarum strain which contains the Escherichia coli lacZ (beta-galactosidase) gene fused to nodABC. Derivatives with an OMe substituent within the reporting group moiety showed residual gene induction activity.