The introduction of a checking technician programme in community pharmacy and its impact on pharmacist activities

Focal points

Toluene degradation kinetics for planktonic and biofilm-grown cells of Pseudomonas putida 54G

Toluene degradation kinetics by biofilm and planktonic cells of Pseudomonas putida 54G were compared in this study. Batch degradation of (14)C toluene was used to evaluate kinetic parameters for planktonic cells. The kinetic parameters determined for toluene degradation were: specific growth rate, micro(max) = 10.08 +/- 1.2/day; half-saturation constant, K(S) = 3.98 +/- 1.28 mg/L; substrate inhibition constant, K(I) = 42.78 +/- 3.87 mg/L. Biofilm cells, grown on ceramic rings in vapor phase bioreactors, were removed and suspended in batch cultures to calculate (14)C toluene degradation rates. Specific activities measured for planktonic and biofilm cells were similar based on toluene degrading cells and total biomass. Long-term toluene exposure reduced specific activities that were based on total biomass for both biofilm and planktonic cells. These results suggest that long-term toluene exposure caused a large portion of the biomass to become inactive, even though the biofilm was not substrate limited. Conversely, specific activities based on numbers of toluene-culturable cells were comparable for both biofilm and planktonically grown cultures. Planktonic cell kinetics are often used in bioreactor models to model substrate degradation and growth of bacteria in biofilms, a procedure we found to be appropriate for this organism. For superior bioreactor design, however, changes in cellular activity that occur during biofilm development should be investigated under conditions relevant to reactor operation before predictive models for bioreactor systems are developed.

Following the surface response of caffeine cocrystals to controlled humidity storage by atomic force microscopy

Active pharmaceutical ingredient (API) stability in solid state tablet formulation is frequently a function of the relative humidity (RH) environment in which the drug is stored. Caffeine is one such problematic API. Previously reported caffeine cocrystals, however, were found to offer increased resistance to caffeine hydrate formation. Here we report on the use of atomic force microscopy (AFM) to image the surface of two caffeine cocrystal systems to look for differences between the surface and bulk response of the cocrystal to storage in controlled humidity environments. Bulk responses have previously been assessed by powder X-ray diffraction. With AFM, pinning sites were identified at step edges on caffeine/oxalic acid, with these sites leading to non-uniform step movement on going from ambient to 0% RH. At RH >75%, areas of fresh crystal growth were seen on the cocrystal surface. In the case of caffeine/malonic acid the cocrystals were observed to absorb water anisotropically after storage at 75% RH for 2 days, affecting the surface topography of the cocrystal. These results show that AFM expands on the data gathered by bulk analytical techniques, such as powder X-ray diffraction, by providing localised surface information. This surface information may be important for better predicting API stability in isolation and at a solid state API-excipient interface.

Two-year-olds with autism orient to non-social contingencies rather than biological motion

Typically developing human infants preferentially attend to biological motion within the first days of life. This ability is highly conserved across species and is believed to be critical for filial attachment and for detection of predators. The neural underpinnings of biological motion perception are overlapping with brain regions involved in perception of basic social signals such as facial expression and gaze direction, and preferential attention to biological motion is seen as a precursor to the capacity for attributing intentions to others. However, in a serendipitous observation, we recently found that an infant with autism failed to recognize point-light displays of biological motion, but was instead highly sensitive to the presence of a non-social, physical contingency that occurred within the stimuli by chance. This observation raised the possibility that perception of biological motion may be altered in children with autism from a very early age, with cascading consequences for both social development and the lifelong impairments in social interaction that are a hallmark of autism spectrum disorders. Here we show that two-year-olds with autism fail to orient towards point-light displays of biological motion, and their viewing behaviour when watching these point-light displays can be explained instead as a response to non-social, physical contingencies--physical contingencies that are disregarded by control children. This observation has far-reaching implications for understanding the altered neurodevelopmental trajectory of brain specialization in autism.

Multidrug-resistant tuberculosis outbreak among US-bound Hmong refugees, Thailand, 2005

In January 2005, tuberculosis (TB), including multidrug-resistant TB (MDR TB), was reported among Hmong refugees who were living in or had recently immigrated to the United States from a camp in Thailand. We investigated TB and drug resistance, enhanced TB screenings, and expanded treatment capacity in the camp. In February 2005, 272 patients with TB (24 MDR TB) remained in the camp. Among 17 MDR TB patients interviewed, 13 were found to be linked socially. Of 23 MDR TB isolates genotyped, 20 were similar according to 3 molecular typing methods. Before enhanced screening was implemented, 46 TB cases (6 MDR TB) were diagnosed in the United States among 9,455 resettled refugees. After enhanced screening had begun, only 4 TB cases (1 MDR TB), were found among 5,705 resettled refugees. An MDR TB outbreak among US-bound refugees led to importation of disease; enhanced pre-immigration TB screening and treatment decreased subsequent importation.

Altered face scanning and impaired recognition of biological motion in a 15-month-old infant with autism

Mounting clinical evidence suggests that abnormalities of social engagement in children with autism are present even during infancy. However, direct experimental documentation of these abnormalities is still limited. In this case report of a 15-month-old infant with autism, we measured visual fixation patterns to both naturalistic and ambiguous social stimuli: video scenes of a caregiver and point-light animations of human action. Results suggested that viewing patterns of the child with autism were driven by the physical contingencies of the stimuli rather than by their social context. If corroborated in larger studies, this observation would advance the hypothesis that mechanisms of social development which rely on preferential engagement with socially contingent conspecifics - and which emerge in the very first weeks of life in typical infants - are developmentally derailed in children with autism.

A strategy for predicting the crystal structures of flexible molecules: the polymorphism of phenobarbital

A computational exploration of the low energy crystal structures of the pharmaceutical molecule phenobarbital is presented as a test of an approach for the crystal structure prediction of flexible molecules. Traditional transferable force field methods of modelling flexible molecules are unreliable for the level of accuracy required in crystal structure prediction and we outline a strategy for improving the evaluation of relative energies of large sets of crystal structures. The approach involves treating the molecule as a set of linked rigid units, whose conformational energy is expressed as a function of the relative orientations of the rigid groups. The conformational energy is calculated by electronic structure methods and the intermolecular interactions using an atomic multipole description of electrostatics. A key consideration in our approach is the scalability to more typical pharmaceutical molecules of higher molecular weight with many more atoms and degrees of flexibility. Based on our calculations, crystal structures are proposed for the as-yet uncharacterised forms IV and V, as well as further polymorphs of phenobarbital.