Influence of corticotropin-releasing factor on pancreatic and islet blood flow in different regions of the rat pancreas

Corticotropin-releasing factor (CRF) has previously been shown to selectively dilate the mesenteric vascular bed, without affecting other vascular beds. Pancreatic blood flow and islet blood flow were therefore measured separately with a microsphere technique in the two regions of the rat pancreas perfused by the superior mesenteric artery (SMA) or celiac artery (CA) respectively. Intravenous infusion of CRF (0.25 microgram/kg b.w./min) caused an increase in both whole pancreatic blood flow and islet blood flow in the region of the pancreas perfused by the SMA. The fraction of whole pancreatic blood flow diverted through the islets in this part of the pancreas was, however, unaffected by CRF infusion (approximately 10%). CRF did not change either pancreatic or islet blood flow in the CA-perfused part of the pancreas, and did not affect the release of insulin.     

Effect of glutamine on protein synthesis in isolated intestinal epithelial cells

The purpose of this study was to determine the etiologic factors of denture stomatitis. Fifteen subjects with clinical evidence of localized simple denture stomatitis, fifteen subjects without clinical signs of denture stomatitis, and forty-five subjects with clinical evidence of generalized simple denture stomatitis were investigated clinically and mycologically. Subjects were evaluated according to age, sex, duration of denture usage, smoking habits, frequency of denture brushing, overnight denture wearing, pH level of saliva and degree of candidal colonization and candidal formation. Salivary samples and swabs were taken from the palate and the mucosal surfaces of the dentures investigated mycologically in order to identify the yeast colonies. Smears were taken from the palate and investigated in order to identify candidal formation. No statistically significant relationship was found between denture stomatitis and age, sex, duration of denture usage, frequency of denture brushing, overnight denture wearing or pH level of saliva. There was however, a statistically significant relationship between denture stomatitis and denture hygiene, smoking habits, candidal colonization and candidal formation.     

Conformational stability of factor VIIa: biophysical studies of thermal and guanidine hydrochloride-induced denaturation

The binding of the multidomain protein factor VIIa (fVIIa) to tissue factor provides the interprotein communication necessary to make fVIIa an efficient catalyst of the initial event in the extrinsic pathway of blood coagulation. We have investigated the stability of individual domains in fVIIa and the influence of Ca2+ and an irreversible active-site inhibitor (FFR-chloromethyl ketone). Equilibrium guanidine hydrochloride (GuHCl)-induced unfolding monitored by tryptophan fluorescence and far-UV circular dichroism (CD) demonstrated that the gamma-carboxyglutamic acid (Gla) domain unfolds at 0.3 M GuHCl and the serine protease (SP) domain at 3 M GuHCl and that Ca2+ is a prerequisite for the formation of an ordered, compact structure in the Gla domain. The loss of amidolytic activity coincides with the first transition, which is stabilized by the active-site inhibitor, and a change in the environment of the active site is demonstrated using a fluorescent inhibitor (DEGR-chloromethyl ketone). Thermal unfolding monitored by differential scanning calorimetry (DSC) reveals that Ca2+ stabilizes the SP domain slightly, increasing the unfolding temperature by 2.7 degrees C. In addition, Ca2+ is required for a large enthalpy change concomitant with unfolding of the Gla domain, and this unfolding enthalpy is only detectable in the presence of the SP domain, indicating some kind of interaction between these domains. Thermal unfolding measured by CD indicates secondary structural changes at the same temperature as the heat absorption in the DSC but only when both the Gla domain and the SP domain are present together with Ca2+ ions. Taken together, these results indicate a Ca2+-dependent interaction between the Gla domain and the SP domain, implying a high degree of flexibility of the domains in free fVIIa. It is also shown that the epidermal growth factor-like domains are stable at elevated temperatures and high GuHCl concentrations. Moreover, already at physiological temperature, subtle structural changes take place which influence the overall shape of fVIIa and are detrimental to its enzymatic activity.     

Photochemical oxidation of fatty acid esters with and without chlorophyll

1. It has been confirmed that the principal products formed in the oxidation of methyl oleate by oxygen under a variety of conditions are predominantlytrans hydroperoxides. However no inversion of the double bond occurs in unoxidized oleate. Hence the conversion ofcis totrans double bonds and peroxide formation occur together in the same molecules.
2. The autoxidation of methyl linoleate at low temperature yields predominantlycis,trans conjugated hydroperoxides. Autoxidation at 25°C., oxidation catalyzed by visible light, or ultraviolet light and copper soap catalyzed oxidation at temperatures appreciably above 0°C., lead to the formation primarily oftrans,trans conjugated hydroperoxides. The inversion of the second double bond in this case appears to be independent of the peroxide-forming reactions.
3. The photochlorophyll oxidation of methyl linoleate leads to the formation of some unconjugated hydroperoxides, some of which containtrans double bonds.
4. Under all of the conditions employed in the present investigation, the oxidation of methyl oleate and linoleate led primarily to the formation of monomeric peroxides which retained most of the unsaturation of the parent compound.

     

A case study of factor influencing role improvisation in crisis response teams

Common characteristics of crisis situations are ambiguous and unplanned for events. The need for improvised roles can therefore be an imperative factor for the success of an operation. The aim of this study is to deepen the understanding of the processes taking place during improvised work “as it happens”. A case study of a crisis management team at work is presented and provides an in-depth analysis of the information and communication flow of persons acting in improvised roles, including contextual factors influencing the task at hand. The analysis suggests that three main factors lay behind decreased performance by the team when some of its members were forced to take on roles for which they lacked professional training; lack of language skills, lack of domain knowledge and insufficient organizational structure of the tasks. Based on the observations from this case study, we suggest three ways of improving a team’s performance and hence resilience when forced to improvise due to lack of personnel in one or more required competence areas. These are training to take on the responsibility for tasks or roles outside ones professional area of specialization, developing formal routines for changes in roles and tasks and developing and using tools and routines for information sharing.