Dual Chamber Pacing with a Single-Lead DDD Pacing System

The successful application of single-lead VDD pacing during the last few years has generated the idea of single-lead DDD pacing. Preliminary data from several single-lead VDD studies attempting to pace the atrium by a floating atrial dipole are unsatisfactory, causing an unacceptably high current drain of the device. We studied the feasibility as well as the short- and long-term stability of atrioventricular sequential pacing, using a new single-pass, tined DDD lead. In eight consecutive patients (age 73+/-16 years) with symptomatic higher degree AV block and intact sinus node function, this new single-pass DDD lead was implanted in combination with a DDDR pacemaker. Correct VDD and DDD function was studied at implantation; at discharge; and at 1, 3, and 6 months of follow-up. At implant, the atrial stimulation threshold was 0.6+/-0.1 V/0.5 ms. During follow-up, the atrial pacing thresholds in different every day positions averaged 2.1+/-0.5 V at discharge, 2.9+/-0.5 V at 1 month, 3.8+/-0.4 V at 3 months, and 3.4+/-0.4 V at 6 months (pulse width always 0.5 ms). The measured P wave amplitude at implantation was 4.5+/-2.2 mV; during follow-up the telemetered atrial sensitivity thresholds averaged 2.1+/-0.3 mV. Phrenic nerve stimulation at high output pacing (5.0 V/0.5 ms) was observed in three (38%) patients at discharge and in one (13%) patient during follow-up; an intermittent unmeasurable atrial lead impedance at 3 and 6 months follow-up was documented in one (13%) patient. This study confirms the possibility of short- and long-term DDD pacing using a single-pass DDD lead. Since atrial stimulation thresholds are still relatively high compared to conventional dual-lead DDD pacing, further improvements of the atrial electrodes are desirable, enabling lower pacing thresholds and optimizing energy requirements as well as minimizing the potential disadvantage of phrenic nerve stimulation.     

Nursing leadership style and psychosocial work environment

malloy t. & penprase b. (2010) Journal of Nursing Management  18 , 715–725
Nursing leadership style and psychosocial work environment Aim This study examines the relationship between leadership style and the psychosocial work environment of registered nurses. Background Research consistently supports the positive relationship between transformational leadership style and job satisfaction. There is less evidence, which identifies the relationship between leadership style and psychosocial work environment. Method The Multifactor Leadership Questionnaire 5× was used to identify the leadership style. The Copenhagen Psychosocial Questionnaire was used to measure psychosocial work environment dimensions. Statistical analysis included Pearson’s r correlation between leadership style and psychosocial work environment and anova to analyse group means. Results There is a significant correlation between leadership style and 22 out of the 37 dimensions of the psychosocial work environment. This correlation was significant ranging from r = 0.88, P < 0.01 to r = 0.18, P < 0.05. Nurses divided into groups based on transformational leadership scores of the immediate supervisor report significant differences in their psychosocial work environment. Conclusion This study supports the significant correlation between leadership style and psychosocial work environment for registered nurses. Implications for nursing management The results of this study suggest that there would be an improvement in the nursing psychosocial work environment by implementation of transformational and contingent reward leadership behaviours.     

Granulomatous hypersensitivity to Schistosoma mansoni EGG antigens in human schistosomiasis. IV. A role for prostaglandin-induced inhibition of in vitro granuloma formation

The prostaglandins (PG) are known to regulate immune cell function(s) and participate in the progression of both acute and chronic inflammatory reactions. Using an in vitro model of Schistosoma mansoni egg-induced hypersensitivity granulomas, we have delineated the role of immune complexes (IC) in the induction and release of PG and their inhibitory effects on granuloma development. The hypersensitivity-type granuloma reaction to soluble egg antigen (SEA) was examined using a model of in vitro granuloma formation. Our results show that granuloma formation was dramatically suppressed by the addition to the granuloma cultures of IC, PGE¹, PGE², while PGF₂ alpha had no significant effect. The inhibition of the PG function was achieved by the introduction of anti-PG antibodies that blocked suppression of granuloma formation. It appears in this model system that IC may inhibit the activity of granuloma formation by stimulating the monocyte-macrophage lineage to release inhibitory mediators. Our results suggest that the prostaglandins E series may be important in the generation and maintenance of suppression of the granulomatous inflammatory response to S. mansoni egg antigens.     

Medical evacuations from the region of former Yugoslavia: The experience of 2 years

In September 1992, the International Organization for Migration(IOM), an intergovernmental humanitarian organization basedin Geneva, Switzerland, implemented the special medical programme(SMP) for the medical evacuation of war victims in former Yugoslavia.For inclusion into the SMP, patients must be victims of war,suffer from a serious medical condition with a favourable prognosis,not treatable locally, be stable enough to survive air traveland withstand delay between medical documentation and actualevacuation. As of August 1994,1,484 patients In need of secondarytreatment not locally available were evacuated to hospitalsin 31 countries. Most patients suffered from fractures, amputationsand nerve injuries. Seventy-two per cent originated from Bosnia-Herzegovina.This paper discusses various problems encountered, such as bureaucraticobstacles, ongoing armed conflict hampering humanitarian activities,lack of funding and the effects of the sustained media attention.     

Taurine Failed to Protect against the Embryotoxic Effects of Isotretinoin in the Rat

Taurine Failed to Protect against the Embryotoxic Effects ofIsotretinoin in the Rat AGNISH, N. D., RUSIN, G., AND DINARDO,B. (1990). Fundam. Appl. To.xicol. 15, 249–257. Experimentalevidence exists to indicate that retinoids may act as detergentsto disrupt biological membranes. Taurine, an amino sulfonicacid, has been shown to possess membrane-stabilizing and cytoprotectiveproperties. This study was undertaken to test whether taurinecoadministered with isotretinoin might be able to protect againstthe teratogenic effects of the retinoid. Our study failed tofind any support for this speculation. Whether challenged againsta 75 (mildly teratogenic) or 150 (very teratogenic) mg/kg/daydose of isotretinoin, taurine for the most part worsened theretinoid embryotoxicity. While in a few combinations taurinedecreased the re-sorption or malformation rate associated withisotretinoin, the decrease was, at best, marginal. In no casewas taurine able to decrease these rates to those noted in thecontrols.     

Accountability,Standards and Accreditation: Exploring the Link

In this paper, the author explores accountability, standards and acreditation as issues affecting health care professionals. The role of accreditation as a mechanism for accountability is described and the notion that accountability is a vital component of quality assurance discussed. The initiatives of particular health care professions in setting standards and promoting quality assurance amongst their members are explored. The author concludes that the health care professions have much to gain from involvement in the process of review and evaluation.     

Histochemical and morphological studies on mammalian epidermal peridermal granules

We performed morphological studies on the epidermal peridermal granules (PG) of newborn mice using histological, fluorescent and electron microscopic methods. PG appeared during the 17th to 18th day of foetal life, and remained in the outermost epidermal layers until 5 days after birth. PG were evenly distributed over the entire cutaneous surface of the mouse, except the tail. PG were found to contain protein and corresponded to sites of transglutaminase activity, but they were devoid of lipids and nucleic acids. They could be differentiated clearly from keratohyalin granules. Together, these studies suggest that PG represent a unique epidermal protein product that serves as a marker of late foetal development.     

Anaesthesia for emergency caesarean section

Summary. The Report on Confidential Enquiries into Maternal Deaths in England and Wales 1982–84 (Department of Health 1989) recommends early involvement of the anaesthetist in women having emergency caesarean sections and the use of epidural anaesthesia in preference to general anaesthesia. In an observational prospective study the need for emergency abdominal delivery could be anticipated in 87% of 360 consecutive emergency caesarean sections. Early establishment of epidural analgesia allowed extension, to an appropriate level for the surgery, in 70%. The duty anaesthetist accompanying the obstetric team on three wardrounds a day could be forewarned of anticipated problems in most women who are eventually delivered abdominally.     

Efficacy of Heparin in Peripheral Venous Infusion in Neonates

OBJECTIVE: To determine the efficacy of continuous, low-dose heparin infusion in prolonging peripheral venous catheter patency in neonates. DESIGN: Randomized, prospective study. SETTING: Level III neonatal intensive-care unit. PARTICIPANTS: 113 neonates requiring i.v. therapy. INTERVENTIONS: The neonates were randomly assigned to heparin (n = 63). The heparin group received 1/2 unit of heparin per milliliter of continuous intravenous infusate or intermittent heparin flush. MAIN OUTCOME MEASURES: Low-dose heparin infusion does not make a difference in the duration of peripheral venous catheter patency. The incidence of catheter-related complications in the heparin group is the same as for those receiving no heparin. RESULTS: The mean duration of catheter patency was 62.75 hours in the heparin group and 27.3 hours in the no-heparin group (p = .0001). The occurrence of infection, bleeding, and extravasation injury was zero in the sample studied. The incidence of phlebitis was 18 cases in 132 (13%) in the heparin group and 13 cases in 122 (10%) in the no-heparin group. According to chi-square analysis, the difference between groups was not statistically significant (p greater than .05). CONCLUSION: Low-dose heparin infusion in peripheral venous catheters in neonates increased the duration of intravenous catheter patency (p = .0001) without increased risks of bleeding, infection, phlebitis, or extravasation injury.