Borderline personality disorder and emotion regulation: insights from the Polyvagal Theory.

The current study provides the first published evidence that the parasympathetic component of the autonomic nervous system differentiates the response profiles between individuals diagnosed with borderline personality disorder (BPD) and controls. Respiratory sinus arrhythmia (RSA), a non-invasive marker of the influence of the myelinated vagal fibers on the heart, and heart period were collected during the presentation of film clips of varying emotional content. The BPD and control groups had similar initial levels of RSA and heart period. However, during the experiment the groups exhibited contrasting trajectories, with the BPD group decreasing RSA and heart period and the control group increasing RSA and heart period. By the end of the experiment, the groups differ significantly on both RSA and heart period. The correlation between the changes in RSA and heart period was significant only for the control group, suggesting that vagal mechanisms mediated the heart period responses only in the control group. The findings were consistent with the Polyvagal Theory [Porges, S. W. (1995). Orienting in a defensive world: Mammalian modifications of our evolutionary heritage: A Polyvagal Theory. Psychophysiology, 32, 301-318; Porges, S. W. (2001). The Polyvagal Theory: Phylogenetic substrates of a social nervous system. International Journal of Psychophysiology, 42, 123-146; Porges, S. W. (2003). Social engagement and attachment: A phylogenetic perspective. Annals of the New York Academy of Sciences, 1008, 31-47.], illustrating different adaptive shifts in autonomic state throughout the course of the experiment. The BPD group ended in a physiological state that supports the mobilization behaviors of fight and flight, while the control group ended in a physiological state that supports social engagement behaviors. These finding are consistent with other published studies demonstrating atypical vagal regulation of the heart with other psychiatric disorders.

Methicillin-resistant/methicillin-sensitive Staphylococcus aureus bacteremia.

OBJECTIVE: To examine the differences between the clinical presentation, management and outcome of persons bacteremic with methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA), after controlling for age, sex and primary diagnosis. METHODS: A review of the clinical records and laboratory data of all MRSA and MSSA bacteremic patients. Fifty matched case-control pairs were further analyzed looking for differences between the 2 populations. The study was carried out in a 500-bed adult tertiary care institution in southwestern Ontario, Canada, between 1994 and 1999. RESULTS: On univariate analysis a) duration of hospitalization prior to bacteremia, b) concomitant polymicrobial bacteremia, c) time to appropriate treatment, were significantly greater in the MRSA infected population. Attributable mortality was also higher, 36%-20%, but this did not achieve significance (p=0.1). On multiple logistic regression analysis, a), b) and c) remained significantly different. CONCLUSION: In a 1:1 matched case-control study of Staphylococcus aureus bacteremia, those infected with MRSA became bacteremic later in their hospital stay, more often had a polymicrobial bacteremia and were appropriately treated later. Although mortality attributable to the MRSA bacteremia was greater, this difference did not achieve significance.

MRSA prevalence in a teaching hospital in Western Saudi Arabia.

OBJECTIVE: To determine the prevalence of Methicillin Resistant Staphylococcus aureus (MRSA) colonization in our institution. METHODS: A 5-day period prevalence study of all adult and pediatric patients. Excluded areas were the adult intensive care unit (screened on admission and weekly thereafter), the outpatient hemodialysis population (screened monthly), and newborns. Our facility is a referral/teaching hospital for the National Guard population and their dependants in Western Saudi Arabia. A total of 240 patients were screened. Nasal sampling was carried out and isolation/identification of MRSA was performed using standard microbiological methods. RESULTS: The total number of patients sampled was 240 and of those 10 (4%) were colonized. The 10 positives were found in 4 patient care areas; adult male medicine 5, adult male oncology 3, adult female medicine one, adult high dependency unit one. These patients care areas had 69 patients (42 males and 27 females). Ten (14%) were colonized by MRSA; 9 males (21%) and one female (3%). Statistical analysis Chi Square for discontinuous variables, "F" test for continuous variables found that one), male gender (p=0.04), 2) the presence of a long term invasive device (p=0.04), 3), length of stay (p=0.004) were predictive of MRSA colonization. CONCLUSION: The overall prevalence of MRSA colonization in our hospital was low, however a sub-segment of the population identified as male, having long term invasive devices, and hospitalized more than 2 weeks, were frequently colonized. Any strategy, in our hospital, to control the spread of MRSA should include the testing of this population.