Dilute solution properties of clindamycin 2-palmitate hydrochloride

Clindamycin 2-palmitate hydrochloride forms micelles in aqueous solution at concentrations above 2·2 times 10^{?3 m}. Dilution of micellar solutions of the drug to concentrations less than 2·0 times 10^{?3 m} produces turbid systems. Turbidity is caused by unionized drug, produced by hydrolysis of the salt, phasing out of solution at concentrations too low for micelles to be formed. Changes in specific conductivity and turbidity associated with the phasing-out process have been measured and explained in terms of the rates of the various processes involved, including demicellization and emulsion stability. The phenomenon of phasing-out, below a critical concentration in aqueous solution, is predicted to be a general one for weakly ionized surfactants where the unionized species possesses low water solubility.     

PROLACTIN STIMULATION BY INTRAVENOUS LABETALOL IS MEDIATED INSIDE THE CENTRAL NERVOUS SYSTEM

We have previously reported that labetalol infusion increases prolactin (PRL) secretion in hypertensive patients. In an attempt to investigate the site where labetalol stimulates PRL, the drug was infused intravenously (100 mg) into healthy subjects, both under basal conditions and after pretreatment with l -dopa plus carbidopa (250 mg and 25 mg respectively every 6 h for 1 day), since this regimen has been reported to blunt the PRL responses to centrally acting stimuli. The effects of oral labetalol administration (100 and 200 mg) on PRL was also evaluated. Serum PRL concentration did not change after oral labetalol, whereas it was increased by intravenous drug administration. This effect was completely abolished by pretreatment with l -dopa plus carbidopa. These findings, though they do not demonstrate the mechanism, suggest that the hyperprolactinaemia induced by labetalol is mediated inside the blood–brain barrier.     

VEGF PROMOTER HAPLOTYPE AND AMYOTROPHIC LATERAL SCLEROSIS (ALS)

Vascular endothelial growth factor (VEGF) is a cytokine essential for angiogenesis. A recent study found that haplotypes, determined by three SNPs ( ? 2,578C/A, ? 1,154 G/A, and ? 634G/C) in the VEGF upstream promoter/leader sequence, were associated with risk of amyotrophic lateral sclerosis (ALS). We used samples and data from a case-control study to examine the relation of ALS to VEGF haplotype. Genotypes at each of the three polymorphic sites were determined using allele-specific primer extension reactions followed by MALDI-TOF. We found a 3-fold increased risk among individuals homozygous for the AAG or AGG haplotypes (95% CI = 0.7 ? 13.4), consistent with the findings of the previous study. Given the wide confidence interval, our findings should be interpreted cautiously.     

Near‐infrared spectroscopy correlates with continuous superior vena cava oxygen saturation in pediatric cardiac surgery patients

Background: Cerebral regional oxygen saturation (rSO₂) measured with near‐infrared spectroscopy (NIRS) has a well‐proven clinical utility. A goal‐oriented treatment based on the rSO₂ resulted in a significant reduction in major morbidity and in a shortening of postoperative hospital stay in patients undergoing coronary revascularization. In this study, we have compared the values of superior vena cava saturation (ScvO₂) continuously measured with a Pediasat catheter and the corresponding NIRS rSO₂ values obtained during cardiac operations in pediatric patients. Methods: This was a prospective observational study enrolling fifteen pediatric patients (age: 6 days–7 years) undergoing cardiac operations. ScvO₂ data obtained with the Pediasat during the operation were compared with simultaneously recorded NIRS rSO₂ values. Results: One hundred and seventeen matched sets of data were obtained during the operation. ScvO₂ continuously measured with the Pediasat was significantly correlated with the corresponding NIRS rSO₂ values. However, there was a constant positive bias (ScvO₂ values were higher than NIRS rSO₂ values) of 5.6%, with a precision of 10.4%. Time‐related percentage changes of NIRS rSO₂ were significantly correlated with the corresponding ScvO₂ percentage changes. A decrease in ScvO₂ is predictive for a decrease in rSO₂ with a sensitivity of 73.7% and a specificity of 85.7%. Conclusions: The continuous measurement of ScvO₂ values obtained by the Pediasat may provide useful information about the metabolic conditions of the brain during cardiac operations in pediatric patients if considered as percentage changes. Absolute values of ScvO₂ tend to overestimate the correspondent rSO₂ values.     

Impact of critical social empowerment on psychological empowerment and job satisfaction in nursing and midwifery settings

casey m., saunders j. & o'hara t. (2010) Journal of Nursing Management   18, 24–34
Impact of critical social empowerment on psychological empowerment and job satisfaction in nursing and midwifery settings
Aim  To test an expanded model of empowerment which specifies the relationships between structural, psychological, critical social empowerment and job satisfaction.
Background  There is evidence that structural empowerment predicts psychological empowerment and these two dimensions of empowerment are independent predictors of job satisfaction. This study explored a third dimension of empowerment – critical social empowerment – and its impact on psychological empowerment and job satisfaction.
Method  A predictive, non-experimental design in a sample of 306 nurses and midwives in Ireland using the Conditions of Work Effectiveness Questionnaire, the Psychological Empowerment Questionnaire, a researcher developed tool to measure critical social empowerment and a job satisfaction questionnaire.
Results  While both structural and critical social empowerment were significant independent predictors of psychological empowerment and job satisfaction, critical social empowerment was the stronger predictor.
Conclusions  The findings support the inclusion of the critical social dimension of empowerment in the understanding of empowerment.
Implications for nursing management  Managers at all levels must attend to critical social empowerment as well as structural empowerment in order to increase job satisfaction, retention and engagement of highly qualified committed nurses and midwives.     

p53 tumour suppressor gene and RAS oncogenes: molecular analysis in the chronic and leukaemic phases of essential thrombocythaemia

A panel of 51 cases of essential thrombocythaemia (ET), in chronic or leukaemic phase, was investigated for p53 gene and RAS oncogenes mutations by PCR-SSCP-direct sequencing. No RAS oncogenes mutations were detected, but p53 mutations were identified in three cases: 1/27 cases (≈4%) in chronic phase not undergoing chemotherapy, 1/19 cases (≈5%) in chronic phase undergoing chemotherapy, and 1/5 cases (20%) which had progressed to leukaemia. Our results suggest that: (1) p53 gene mutations occur sporadically in the chronic phase of ET, independent of chemotherapy, and may contribute to the progression to the leukaemic phase in a limited number of ET patients; (2) the RAS genes family does not seem to be involved in the pathogenesis of ET, unlike other bcr/abl negative chronic myeloproliferative diseases (CMPDs).