Morphological variation and phylogenetic analysis of the dinoflagellate Gymnodinium aureolum from a tributary of Chesapeake Bay

Cultures of four strains of the dinoflagellate Gymnodinium aureolum (Hulburt) G. Hansen were established from the Elizabeth River, a tidal tributary of the Chesapeake Bay, USA. Light microscopy, scanning electron microscopy, nuclear-encoded large sub-unit rDNA sequencing, and culturing observations were conducted to further characterize this species. Observations of morphology included: a multiple structured apical groove; a peduncle located between the emerging points of the two flagella; pentagonal and hexagonal vesicles on the amphiesma; production and germination of resting cysts; variation in the location of the nucleus within the center of the cell; a longitudinal ventral concavity; and considerable variation in cell width/length and overall cell size. A fish bioassay using juvenile sheepshead minnows detected no ichthyotoxicity from any of the strains over a 48-h period. Molecular analysis confirmed the dinoflagellate was conspecific with G. aureolum strains from around the world, and formed a cluster along with several other Gymnodinium species. Morphological evidence suggests that further research is necessary to examine the relationship between G. aureolum and a possibly closely related species Gymnodinium maguelonnense.     

Focal adhesion kinase and beta1 integrin regulation of Na+, K+, 2Cl- cotransporter in osmosensing ion transporting cells of killifish, Fundulus heteroclitus

Focal adhesion kinase (FAK), also known as PYK2, is a tyrosine kinase that functions in integrin-mediated signaling in mechanosensitive cells but its role in osmosensing cells is unknown. Antibodies directed against phosphorylated FAK, whose epitopes are conserved among vertebrates, were used to follow phosphorylation patterns in an osmosensing ion secreting epithelium, the killifish (Fundulus heteroclitus) opercular membrane. At the electron microscopic level, a unique combination of integrin beta1, the phosphorylated form of FAK at tyrosine 407 (pY407) and Na(+), K(+), 2Cl(-) cotransporter (NKCC1) were all colocalized only on the basolateral membrane in chloride cells. The three proteins were also coimmunoprecipitated with each other in isotonic conditions, suggesting an osmosensing complex involving the three proteins. Only FAK pY407 was sensitive to hypotonic shock and became dephosphorylated with hypotonic shock, while FAK pY576 in the apical membrane and pY861 in cell-cell adhesions were insensitive to hypotonicity. NKCC1 contributes to NaCl secretion in seawater and previous reports showed that hypotonic shock (-60 mOsm/kg) rapidly inhibits Cl(-) secretion. These results indicate that chloride cells respond to hypotonic shock using integrin beta1 as an osmosensor that is connected to dephosphorylation of FAK pY407 which leads to NKCC1 deactivation in the basolateral membrane and the inhibition of NaCl secretion by these epithelial cells.     

Accuracy of diagnostic registers and management of chronic obstructive pulmonary disease: the Devon primary care audit

Background

Guidelines on COPD diagnosis and management encourage primary care physicians to detect the disease at an early stage and to treat patients according to their condition and needs. Problems in guideline implementation include difficulties in diagnosis, using spirometry and the disputed role of reversibility testing. These lead to inaccurate diagnostic registers and inadequacy of administered treatments. This study represents an audit of COPD diagnosis and management in primary care practices in Devon.

Methods

Six hundred and thirty two patients on COPD registers in primary care practices were seen by a visiting Respiratory Specialist Nurse. Diagnoses were made according to the NICE guidelines. Reversibility testing was carried out either routinely or based on clinical indication in two sub-samples. Dyspnoea was assessed. Data were entered into a novel IT-based software which computed guideline-based treatment recommendations. Current and recommended treatments were compared.

Results

Five hundred and eighty patients had spirometry. Diagnoses of COPD were confirmed in 422 patients (73%). Thirty nine patients were identified as asthma only, 94 had normal spirometry, 23 were restrictive and 2 had a cardiac disorder. Reversibility testing changed diagnosis of 11% of patients with airflow obstruction, and severity grading in 18%. Three quarters of patients with COPD had been offered practical help with smoking cessation. Short and long-acting anticholinergics and long acting beta-2 agonists had been under-prescribed; in 15–18% of patients they were indicated but not received. Inhaled steroids had been over-prescribed (recommended in 17%; taken by 60%), whereas only 4% of patients with a chronic productive cough were receiving mucolytics. Pulmonary rehabilitation was not available in some areas and was under-used in other areas.

Conclusion

Diagnostic registers of COPD in primary care contain mistakes leading to inaccurate prevalence estimates and inappropriate treatment decisions. Use of pre-bronchodilator readings for diagnosis overestimates the prevalence and severity in a significant minority, thus post bronchodilator readings should be used. Management of stable COPD does often not correspond to guidelines. The IT system used in this study has the potential to improve diagnosis and management of COPD in primary care.     

Global transcriptional response to mammalian temperature provides new insight into <Emphasis Type="Italic">Francisella tularensis</Emphasis> pathogenesis

Background  

After infecting a mammalian host, the facultative intracellular bacterium,Francisella tularensis, encounters an elevated environmental temperature. We hypothesized that this temperature change may regulate genes essential for infection.