Network Analysis of Posttraumatic Stress Experiences of Adults Seeking Psychological Treatment for Childhood Sexual Abuse

Network analysis proposes that mental disorders may best be construed as causal systems embodied in networks of functionally interconnected symptoms. We employed network analysis to test how adult survivors of childhood sexual abuse (CSA) experienced symptoms of posttraumatic stress, using alternative conceptualizations of posttraumatic stress disorder (PTSD). Given the characteristics of the sample (i.e., the nature of and time since trauma), we hypothesized that (a) symptoms related to arousal would not be prominent in the networks and (b) symptoms related to negative alternations in cognition and mood (NACM) would be core components in the network. Danish adults seeking psychological treatment for CSA (n = 473) completed the Harvard Trauma Questionnaire and Trauma Symptom Checklist. Three alternative models (DSM-5, DSM-5 with dissociation, and ICD-11 complex PTSD [CPTSD]) were estimated using regularized partial correlation models. In the DSM-5 network, strong associations emerged for experiences of NACM (blame and guilt) and intrusions (thoughts and flashbacks). The addition of “depersonalization” and “derealization” to the DSM-5 model produced a strong association, but these experiences were largely unrelated to other PTSD clusters. In the CPTSD network, interpersonal problems and negative self-concept were central to the survivors’ experiences. For this highly-specific survivor group who experienced traumatic CSA many years ago, experiences related to NACM appeared to be more central to the posttrauma experience than those of arousal. If replicated, these findings could help inform treatment plans for specific groups of survivors. Methodological implications as to the usefulness of network models in the psychopathological research literature are discussed.     

On the use of monocrystalline antimony pH electrodes in gastro-oesophageal functional disorders

Monocrystalline antimony electrodes have been shown to be suitable for thein vivo determination of pH in blood, tissue and in the upper gastro-intestinal canal. Thanks to their small dimensions it has been possible to mount them into conventional manometry catheters for oesophageal investigation. The monocrystalline antimony pH electrode has several advantages over the conventional pH glass electrode; better accuracy, shorter rise time, smaller dimensions. The monocrystalline antimony electrode has been used for long-term registration of gastro-oesophageal reflux, for the oesophageal acid clearing test and for identification of the pH gradient zone between the gastric and oesophageal mucosa. Its use in combination with pressure sensors has added a new dimension to the diagnosis of functional disorders in the gastro-oesophageal region.     

Transport of methylmercury and inorganic mercury to the fetus and breast-fed infant

It is well established that methylmercury (MeHg) and mercury vapor pass the placenta, but little is known about infant exposure via breast milk. We measured MeHg and inorganic mercury (I-Hg) in blood of Swedish mothers (n = 20) and their infants, as well as total mercury (T-Hg) in breast milk up to 13 weeks postpartum. Infant blood MeHg was highly associated with maternal blood MeHg at delivery, although more than twice as high. Infant MeHg decreased markedly until 13 weeks of age. Infant blood I-Hg was associated with, and about as high as, maternal blood I-Hg at delivery. Infant I-Hg decreased until 13 weeks. In breast milk, T-Hg decreased significantly from day 4 to 6 weeks after delivery but remained unchanged thereafter. At 13 weeks, T-Hg in breast milk was associated with infant MeHg but not with maternal MeHg. Conversely, T-Hg in breast milk was associated with maternal I-Hg but not with infant I-Hg. From the findings of the present study in which the exposure to both MeHg and I-Hg was low, we conclude that the exposure to both forms of mercury is higher before birth than during the breast-feeding period, and that MeHg seems to contribute more than I-Hg to infant exposure postnatally via breast milk.     

DNA fingerprinting of isolates of Staphylococcus aureus from newborns and their contacts

During a study on the epidemiology of Staphylococcus aureus colonization in newborns, mothers, and hospital staff, S. aureus was isolated from 536 of 1,945 specimens. Ninety-three isolates of S. aureus from the three groups of individuals were included in a study to evaluate the potential of DNA fingerprinting for strain differentiation. The 93 isolates were also phage typed and their plasmid profiles were analyzed. Cleavage of DNA with BamHI resulted in 13 different DNA restriction endonuclease band patterns (DNA REBPs), one of which consisted of eight isolates whose DNA was not cleaved with BamHI. The DNAs from these eight isolates were easily cleaved with HindIII. The different DNA REBPs were stable both during in vitro and in vivo growth and allowed strain differentiation within phage groups or types. We could not show any strong association between DNA REBP classes, phage types or groups, and plasmid profiles. Of the 93 isolates, 27 (29.0%) could not be phage typed and 12 (12.9%) lacked plasmids. We therefore conclude that DNA fingerprinting is a powerful tool, in addition to phage typing and plasmid profile analysis, for strain differentiation of S. aureus.     

Selective monoamine oxidase inhibitors. 4. 4-Aminophenethylamine derivatives with neuron-selective action

Nine 4-aminophenethylamine derivatives were synthesized and tested for monoamine oxidase (MAO) inhibitory effects with particular attention to their selectivity for MAO within monoaminergic neurons in the rat brain. All compounds selectively inhibited the A form of MAO in vitro. Some of the compounds inhibited the MAO within the monoaminergic neurons at much lower doses than those required for inhibition of MAO within other cells in vivo. The most potent compounds in this respect were 4-amino-2-fluoro-alpha-methylphenethylamine (5) and 4-amino-2-chloro-alpha-methylphenethylamine (4).     

Pediatric cardiac output measurement using surface integration of velocity vectors: an in vivo validation study

OBJECTIVE: To test the accuracy and reproducibility of systemic cardiac output (CO) measurements using surface integration of velocity vectors (SIVV) in a pediatric animal model with hemodynamic instability and to compare SIVV with traditional pulsed-wave Doppler measurements. DESIGN: Prospective, comparative study. SETTING: Animal research laboratory at a university medical center. SUBJECTS: Eight piglets weighing 10-15 kg. INTERVENTIONS: Hemodynamic instability was induced by using inhalation of isoflurane and infusions of colloid and dobutamine. MEASUREMENTS: SIVV CO was measured at the left ventricular outflow tract, the aortic valve, and ascending aorta. Transit time CO was used as the reference standard. RESULTS: There was good agreement between SIVV and transit time CO. At high frame rates, the mean difference +/- 2 SD between the two methods was 0.01+/-0.27 L/min for measurements at the left ventricular outflow tract, 0.08+/-0.26 L/min for the ascending aorta, and 0.06+/-0.25 L/min for the aortic valve. At low frame rates, measurements were 0.06+/-0.25, 0.19+/-0.32, and 0.14+/-0.30 L/min for the left ventricular outflow tract, ascending aorta, and aortic valve, respectively. There were no differences between the three sites at high frame rates. Agreement between pulsed-wave Doppler and transit time CO was poorer, with a mean difference +/- 2 SD of 0.09+/-0.93 L/min. Repeated SIVV measurements taken at a period of relative hemodynamic stability differed by a mean difference +/-2 SD of 0.01+/-0.22 L/min, with a coefficient of variation = 7.6%. Intraobserver coefficients of variation were 5.7%, 4.9%, and 4.1% at the left ventricular outflow tract, ascending aorta, and aortic valve, respectively. Interobserver variability was also small, with a coefficient of variation = 8.5%. CONCLUSIONS: SIVV is an accurate and reproducible flow measurement technique. It is a considerable improvement over currently used methods and is applicable to pediatric critical care.     

Pressure half-time does not always predict mitral valve area correctly

A theory is presented elucidating factors that influence the pressure half-time. By combining the Bernoulli and continuity equations and making certain assumptions about the shape of the atrioventricular pressure difference decay, it can be shown that valve area, volume transported across that area, and initial pressure difference influence the pressure half-time according to a formula in which the pressure half-time is related to V/(Ao square root of delta po), where V is the transported volume across the orifice with the area Ao, and delta po is the initial pressure difference across that area. In a subsequent hydraulic model experiment pressure half-time was determined for three different hole areas, with various initial volumes and initial pressure gradients. We did not obtain a unique relation between the pressure half-time and area. Instead the results supported our theory, and we found a close linear relationship between area and V/(T0.5 square root of delta po) (correlation coefficient [r] = 0.998), as predicted in the theory (T0.5 = pressure half-time). Clinical examples in which the pressure half-time may be misleading in the assessment of severity of mitral stenosis are presented.