Hemodynamic comparison of ventricular pacing, atrioventricular sequential pacing, and atrial synchronous ventricular pacing using radionuclide ventriculography

To assess the hemodynamic effects of physiologic pacing, 13 patients with DDD pacemakers who had varying degrees of atrioventricular (AV) block were studied with radionuclide ventriculography during VVI, DVI and VDD modes. Radionuclide ventriculography was performed with patient in the supine position at rest 5 to 10 minutes after the pacing mode and AV delay were changed. The AV delays selected were short (mean 147 +/- 4.8 ms) and long (mean 197 +/- 4.8 ms), with a constant difference of 50 ms. During VVI, 6 patients (group 1) had a left ventricular ejection fraction of 40% or less (mean 22 +/- 11) and 7 patients (group 2) had an ejection fraction of more than 40% (mean 59 +/- 11). Comparisons of ejection fraction, end-diastolic volume and cardiac index between VVI and both modes of AV pacing (VDD and DVI) and between long and short AV delays led to the following conclusions: DVI or VDD pacing produces more beneficial hemodynamic effects than VVI, and these effects are more pronounced in patients with low ejection fraction if longer AV delay is used. The VDD mode significantly improves ventricular function over the DVI mode in patients with an ejection fraction of more than 40% independent of heart rate. Longer AV delay is essential in patients with an ejection fraction of 40% or less to improve ventricular function with physiologic pacing.     

Differential effects of G-CSF mobilisation on dendritic cell subsets in normal allogeneic donors and patients undergoing autologous transplantation

It has been suggested that the immunological properties of cytokine primed PBSC may reflect the presence of altered levels of cellular components. In this study the changes induced in blood dendritic cell (DC) subsets following G-CSF mobilisation are analysed. Analysis of normal donors (n = 64) demonstrated considerable individual variation in the absolute numbers (x10(6)/l) of resting blood CD11c(-) DC (1.2-26.2) and CD11c(+) DC (0.9-34.7) as well as in the CD11c(-)/CD11c(+) DC ratio (0.29-4.13). G-CSF therapy increased CD11c(-) DC numbers to above the normal range in all normal donors analysed (n = 6) and the CD11c(-)/CD11c(+) ratio was also increased to >2.0 in all donors. Patients undergoing autologous PBSCT showed a heterogeneous response to mobilisation and although total DC and CD11c(-) DC numbers were increased in the majority (8/14), they remained within the normal range post mobilisation. The CD11c(-)/CD11c(+) ratio decreased in 5/15 patients and only three patients had ratios >2.0 post mobilisation. Post G-CSF the DC from all normal donors and 13/14 patients had an immature phenotype. These results demonstrate that G-CSF mobilisation induces relatively consistent changes in the number and ratio of DC subsets in normal donors, but considerable variation is seen in the response of patients undergoing mobilisation for autologous PBSCT.     

The effect of intraluteal infusion of deglycosylated human chorionic gonadotropin on the corpus luteum in rhesus monkeys

Removal of the carbohydrates from hCG results in an antagonist (degly-hCG) that competitively inhibits hCG/LH-stimulated adenylate cyclase in macaque luteal tissue in vitro, but its effect in vivo is controversial. To examine the effect of degly-hCG on the lifespan and steroidogenic activity of the primate corpus luteum, the antagonist was administered to female rhesus monkeys (n = 7) beginning at the midluteal phase of the menstrual cycle. In a control cycle the saline vehicle was infused via an osmotic minipump directly into the corpus luteum. In a subsequent cycle, one of three dose rates of degly-hCG (0.001, 0.009, and 0.09 nmol/h) was infused into the corpus luteum. Pump implantation and infusion began 5-9 days after the midcycle LH surge and continued for 7 days. Peripheral venous blood was collected daily from day 8 of the cycle until menses, and serum progesterone levels were determined by RIA. Progesterone levels and patterns were similar in animals that received either the saline vehicle or degly-hCG, and the length of the luteal phase in monkeys receiving any dose of degly-hCG (16.4 +/- 0.5 days) was not different from that in animals receiving a control infusion (16.1 +/- 0.9 days). In a corollary study, an intraluteal infusion of degly-hCG (0.009 nmol/h) in the midluteal phase did not prevent stimulation of progesterone levels after im injection of hCG (15 IU/day for 5 days). We conclude that whereas degly-hCG is a useful tool to examine gonadotropin action in vitro, it is not a potent gonadotropin antagonist in vivo.     

Borrelia burgdorferi bba66 Gene Inactivation Results in Attenuated Mouse Infection by Tick Transmission

The impact of the Borrelia burgdorferi surface-localized immunogenic lipoprotein BBA66 on vector and host infection was evaluated by inactivating the encoding gene, bba66, and characterizing the mutant phenotype throughout the natural mouse-tick-mouse cycle. The BBA66-deficient mutant isolate, Bb^ΔA66, remained infectious in mice by needle inoculation of cultured organisms, but differences in spirochete burden and pathology in the tibiotarsal joint were observed relative to the parental wild-type (WT) strain. Ixodes scapularis larvae successfully acquired Bb^ΔA66 following feeding on infected mice, and the organisms persisted in these ticks through the molt to nymphs. A series of tick transmission experiments (n = 7) demonstrated that the ability of Bb^ΔA66-infected nymphs to infect laboratory mice was significantly impaired compared to that of mice fed upon by WT-infected ticks. trans-complementation of Bb^ΔA66 with an intact copy of bba66 restored the WT infectious phenotype in mice via tick transmission. These results suggest a role for BBA66 in facilitating B. burgdorferi dissemination and transmission from the tick vector to the mammalian host as part of the disease process for Lyme borreliosis.     

eHealth for neonatal nurse education despite Covid-19

AimThe aim of this contemporary issue paper is to challenge the premise that the term “eHealth” is relatable to patient or service users only. It will be critically explored if the term can be broadened to include neonatal nurse education interventions.DesignA review of current literature will form the basis for the critical discussion of the term eHealth, and why it can be associated with neonatal nurse education.MethodsThe critical discussion will identify and review past and current literature relating to eHealth and its origins. It will portray the viability of the term eHealth as more than just a patient associated intervention, and why it should also be encompassed as a neonatal nurse education option.ConclusioneHealth is traditionally identifiable as a service user intervention or source of information. The term should be broadened to encompass neonatal nurse education and used as a resource that is easily accessible and user friendly. This will in turn encourage the personal and professional development of neonatal nurses and should ultimately contribute to evidence based best practices in the clinical environment, despite the current global pandemic.     

Menstrual Cycle Effects on Psychological Symptoms in Women With PTSD

The menstrual cycle has been implicated as a sex‐specific biological process influencing psychological symptoms across a variety of disorders. Limited research exists regarding the role of the menstrual cycle in psychological symptoms among women with posttraumatic stress disorder (PTSD). The current study examined the severity of a broad range of psychological symptoms in both the early follicular (Days 2–6) and midluteal (6–10 days postlutenizing hormone surge) phases of the menstrual cycle in a sample of trauma‐exposed women with and without PTSD (N = 49). In the sample overall, total psychological symptoms (d = 0.63), as well as depression (d = 0.81) and phobic anxiety (d = 0.81) symptoms, specifically, were increased in the early follicular compared to midluteal phase. The impact of menstrual cycle phase on phobic anxiety was modified by a significant PTSD × Menstrual Phase interaction (d = 0.63). Women with PTSD reported more severe phobic anxiety during the early follicular versus midluteal phase, whereas phobic anxiety did not differ across the menstrual cycle in women without PTSD. Thus, the menstrual cycle appears to impact fear‐related symptoms in women with PTSD. The clinical implications of the findings and future research directions are discussed.     

Myocardial disarray in Noonan syndrome

Objective—To characterise the histopathology of the left ventricular hypertrophy commonly associated with Noonan syndrome by assessing the extent of myocyte disarray and therefore to define one aspect of the relation between this disease and idiopathic hypertrophic cardiomyopathy.

Design—Blinded histological analysis.

Setting—Hospital medical school.

Patients—Six hearts of children with the Noonan phenotype and isolated ventricular hypertrophy were compared with age and sex matched controls.

Methods—Histological analysis was performed with an image analyser under light microscopy. Representative sections from the entire left ventricular free wall were examined. Results were expressed as the percentage of fields showing disarray related to the number of fields evaluated: 100 fields were examined for each patient.

Results—In the patients with Noonan syndrome myocardial disarray was present in the ventricular septum in 24 (5·7)% (mean (SD)) of fields and in the free wall in 22·2 (6·8)%. In the controls disarray was present in the septum in 3·8 (2·3)% of fields and in the free wall in 2·4 (2·8)%. In both regions the extent of disarray was significantly greater in patients with Noonan syndrome (p < 0·0005; 95% confidence interval 14 to 26·3 for the septum: p < 0·005, 95% confidence interval 11·4 to 28·2 for the free wall).

Conclusions—The ventricular hypertrophy associated with Noonan syndrome is histologically similar to hypertrophic cardiomyopathy but whether the two diseases are the expression of the same genetic defect remains to be determined.