Direct and Telemetered Lead Impedance

Objectives: We undertook this study to determine whether telemetered lead impedance measurements (LIM) can be correlated with direct LIM and to determine the stability of LIM over time when measured directly and via telemetry. Methods: Direct LIM and telemetered LIM were measured in 91 patients; 101 leads during initial implantation and 40 leads during pulse generator replacement. Differences in direct LIM measured during initial implant and pulse generator replacement (direct-direct) were compared in 41 patients (28 atrial leads and 37 ventricular leads). The stability of telemetered LIM obtained immediately postoperatively, at 1 month and 1 year, postimplantation was assessed in 50 patients (23 atrial and 49 ventricular leads). Results: In atrial leads acute direct LIM was 633.9 ± 18.4 Ω versus 575.8 ± 18.5 Ω for telemetered LIM (r = 0.58), and chronic direct LIM was 670.9 ± 49.3 Ω versus 607.0 ± 36.3 Ω for telemetered LIM (r = 0.87). In ventricular leads acute direct LIM was 747.3 ± 16.9 Ω and 684.7 ± 16.4 Ω for telemetered LIM (r = 0.69), and chronic direct LIM was 674.8 ± 29.9 Ω and 625.2 ± 28.5 Ω for telemetered LIM (r = 0.68). The mean direct–direct UM rose 124 Ω (P < 0.001) in atrial leads and 10 Ω (P = NS) in ventricular leads. Telemetered LIM for atrial leads was 581.0 ± 27.6 Ω immediately postimplantation compared to 625.7 ± 34.8 Ω at 1 month and 754.1 ± 43.0 Ω at 1 year. Telemetered LIM for ventricular leads was 661.3 ± 17.5 Ω at implant, 684.6 ± 20.7 Ω at 1 month and 724.7 ± 22.7 Ω at 1 year. Conclusions: There is a good but limited correlation between direct and telemetered LIM. Mean direct LIM obtained at initial implantation is similar to that measured at pulse generator replacement. The telemetered LIM is stable over the first month postimplantation but tends to rise during the first year of follow-up and substantial changes in impedance are not uncommon in individuals with normal function. There is a tendency for LIM to rise with lead maturation. If telemetered LIM is to be followed over time, a baseline telemetered value should be obtained immediately postoperatively.     

H-Y Antigen Expression Patterns in Human X- and Y-Chromosome-Bearing Spermatozoa

PROBLEM: Restricted expression of H-Y antigen on Y-chromosome-bearing sperm has been reported in some species, although such preferential expression for H-Y antigen in human sperm has yet to be described. In this study, an immunomagnetic approach was used to characterize antigen expression patterns as a function of sex-chromosome content. METHOD OF STUDY: Human sperm was treated with monoclonal immunoglobulin (Ig) M antibodies directed against H-Y antigen. This preparation then was incubated with sheep antimouse IgM antibody affixed to paramagnetic beads, which then were exposed to a magnetic field and sorted. X- and Y-chromosome frequencies in the two subgroups of sperm were assayed by multiprobe fluorescent in situ hybridization (FISH). RESULTS: Sperm were immunomagnetically separated into two populations: a reactive group (presumably, H-Y Ag+); and a nonreactive group (presumably, H-Y Ag-). Triple-color FISH analysis of 1,600 spermatozoa (800 in each group) showed the antigen's expression to be somewhat more prevalent among Y-chromosome-bearing sperm (54.1%), but a large proportion of Y-chromosome-bearing sperm (49.0%) did not express this antigen. The difference was not significant (P = 0.43). CONCLUSIONS: The expression of H-Y antigen has a slightly higher frequency in human sperm containing the Y-chromosome, but its expression among X-chromosome-bearing sperm also is considerable. Current immunologic techniques relying on this antigen are unlikely to effect the sex selection of human sperm.     

Exercising attention within the classroom

Aim To investigate whether increased physical exercise during the school day influenced subsequent cognitive performance in the classroom. Method A randomized, crossover‐design trial (two weeks in duration) was conducted in six mainstream primary schools (1224 children aged 8–11y). No data on sex was available. Children received a teacher‐directed, classroom‐based programme of physical exercise, delivered approximately 30 minutes after lunch for 15 minutes during one week and no exercise programme during the other (order counterbalanced across participants). At the end of each school day, they completed one of five psychometric tests (paced serial addition, size ordering, listening span, digit‐span backwards, and digit‐symbol encoding), so that each test was delivered once after exercise and once after no exercise. Results General linear modelling analysis demonstrated a significant interaction between intervention and counterbalance group (p<0.001), showing that exercise benefitted cognitive performance. Post‐hoc analysis revealed that benefits occurred in participants who received the exercise intervention in the second but not the first week of the experiment and were also moderated by type of test and age group. Interpretation Physical exercise benefits cognitive performance within the classroom. The degree of benefit depends on the context of testing and participants’ characteristics. This has implications for the role that is attributed to physical exercise within the school curriculum.     

Serum ferritin in term and preterm infants

Serum ferritin levels were examined in maternal serum, In cord sera and at one, four, eight and twelve weeks in 19 term and 28 preterm infants. There was no correlation between maternal and cord ferritin levels. Mean serum ferritin concentration was lower in preterm infants, and both term and preterm Infants exhibited' an initial rise in serum ferritin concentration followed by a steady fall. Serum ferritin concentration showed a good correlation with calculated iron stores at twelve weeks of age suggesting that serum ferritin estimation is the method of choice for monitoring body iron stores in infants. No correlation was found between serum ferritin concentration and calculated iron intake at any age in either term or preterm infants. It is suggested that iron supplementation additional to that present in modified cow's milk is not necessary for the first twelve weeks of life in either term or preterm infants.     

Evaluation of Drug and Chemical Toxicity with Cell Culture Systems

Evaluation of Drug and Chemical Toxicity with Cell Culture Systems.BRADLAW, J. A. (1986). Fundam. Appl. Toxicol. 6, 598–606.Approaches to the evaluation of drug and other chemical toxicitywith mammalian cell culture systems are designed to enhancethe predictability of animal models. Identification of toxicagents by in vitro screening tests and studies of mechanismsthrough which chemicals induce critical lesions at the cellularand subcellular levels help to make those predictions soonerand perhaps single out those target sites and chemicals of mostconcern.     

Contradictory Shear Stress Distribution Prevents Restenosis after Provisional Stenting for Bifurcation Lesions

Background: Endothelial shear stress is one of the local hemodynamic factors suspected in the development of coronary atherosclerosis in bifurcation lesions. In patients with provisional stenting, the endothelial shear stress (SS) distribution is unknown. Objective: The aim of this study was to investigate the magnitude and distribution of the SS of coronary bifurcation lesions stenting by the provisional approach. Methods: Ten consecutive patients were included in this study. Quantitative coronary analysis, flow study, and three‐dimensional computational analysis with the aid of the commercial software CD STAR‐CCM+ were done before and after the provisional stenting procedure and also 8 months later. Results: Clinical and angiographic follow‐up were available in all patients. No patient had a side branch (SB) stent. At the 8‐month follow‐up, no major adverse cardiac event (MACE) occurred. There was also no clinical and angiographic restenosis. Before PCI, the distal main vessel (MV)‐lateral, and the SB‐lateral subsegments had relative nonsignificant lower SS value (4.08 ± 2.78 Pa and 4.35 ± 5.04 Pa, respectively) when compared to other segments. After 8‐month follow‐up, sustained decreased SS value was shown in the distal MV‐lateral segment (4.08 ± 2.78–1.68 ± 1.65 Pa), when compared with significantly increased SS value in the SB‐lateral subsegment 4.35 ± 5.04–16.50 ± 40.45 Pa). The explanation is that after stenting in the MV, the flow was redistributed immediately after percutaneous coronary intervention (PCI) and reversed back to its original 8 months later. However, the growth of the fibrous tissue causing in‐stent restenosis (ISR) is prohibited by sirolimus on the stent struts. In contrast, in a branch opened up by plain old balloon angioplasty (POBA), the flow did not change much, the flow could even be worse because it is shifted to the MV after the cross‐sectional area of the MV improved by stenting. However, thanks to POBA, there is increased fibrous tissue formation, enough to increase the SS and prevent further accumulation of cell and cholesterol needed for more restenosis. Conclusion: In the provisional approach, low endothelial SS correlated with no restenosis for patients who underwent stenting of the MV, while a contradictory combination of high SS and no restenosis was seen in the SB after only POBA. The mechanism of prevention of restenosis in the SB is by increasing the SS while in the MV, the mechanism of prevention of ISR is secondary to sirolimus on the stents struts. (J Interven Cardiol 2010;23:319–329)     

The New Genetics

Genetic factors are responsible for 30% of pediatric hospital admissions. They also contribute to birth defects in 4% of newborns and chronic diseases in 10% of adults. Nurses working in maternal-child health need to have current information on the new genetics. With knowledge of the tools, applications, and implications of genetic engineering, nurses can be resources to families at risk for heritable diseases.     

Is interstitial cystitis an allergic disorder?: A case of interstitial cystitis treated successfully with anti-IgE

Interstitial cystitis (IC) is a chronic disorder diagnosed by symptomatology of pelvic pain and urinary frequency, which are extremely variable and unpredictable fluctuating among patients. IC has recently been found combined with some allergic disorders and histopathologic abnormalities resembling that of allergic disorders, including mast cell activation, histamine release and eosinophil infiltration. Therefore, it could be cautiously postulated that IC is one of the allergic disorders of the urogenital system. A 28-year-old Caucasian female patient, who was diagnosed with asthma and allergic rhinitis, suffered from bladder symptoms of frequency, urgency and pelvic pain for the past 3 years. The symptoms disturbed her every day and were intractable for treatment. Urologists concluded that she had interstitial cystitis. Specific immunotherapy (SIT) was recommended for her allergic symptoms. While taking specific immunotherapy, she had anaphylaxis. She still had the reaction even with the 1000-fold diluted shot of SIT. Omalizumab was used for her allergic symptoms and possible prevention of anaphylactic reaction to SIT. Interestingly, she reported that her urogenital symptoms had subsided since omalizumab had been started. According to the published literature, we postulate that interstitial cystitis might be one of the IgE mediated, mast cell driven allergic disorders of the urogenital system. Therefore, in this case, the patient's bladder symptoms are successfully controlled primarily by anti-IgE therapy and the improvement could be maintained by SIT. We report, for the first time, a case of interstitial cystitis with allergic rhinitis and asthma, successfully treated by anti-IgE therapy and specific immunotherapy.     

Development og Kidney Tumors in the Male F344/N Rat after Treatment with Dimtheyl Methylphosphonate

Development of Kidney Tumors in the Male F344/N Rat after Treatmentwith Dimethyl Methylphosphonate. Dunnick, J. K., Eusns, S. L.,and Haseman, J. K. Fundam. Appl. Toxi-col. 11,91 -99. Dimethylmethylphosphonate (DMMP), a chemical that has been used as aflame retardant and as a nerve gas simulant to mimic the physicalbut not biologic properties of nerve gases, was administeredby gavage in corn oil for up to 2 years at doses of 0, 500,or 1000 mg/ kg/day to male and female F344/N rats and at dosesof 0, 1000, or 2000 mg/kg/day to male and female B6C3F, mice.Survival in dosed male rats was reduced, due in part to kidneytoxicity, and lesions in the kidney included increased severityof spontaneous nephropathy, calcification, hyperplarium, tubularcell adenocarcinomas, and transitional cell papillomas and carcinomas.Survival in female rats was similar among groups; survival inmice was reduced and this reduced survival decreased the sensitivityfor detecting a carcinogenic response. There were no dose relatedneoplastic responses in female rats or male or female mice.The spectrum of kidney lesions seen in the male rat given DMMPis similar to that seen after the long-term administration ofa variety of other chemicals including unleaded gasoline, hydrocarbonsolvents, and 1,4-dichlorobenzene.     

L.E. Cells in Lymphoma

Two elderly women suffering from lymphoma—lymphosarcoma and Hodgkin’s disease respectively—had positive L.E. cell tests.

In one case the L.E. phenomenon was strongly and consistently positive,as were tests for thyroglobulin antibody and rheumatoid factor; treatmentwith radioactive phosphorus was beneficial.

The origin of antinuclear and other autoantibodies in lymphoma could beattributed to (a) the development of self-reactivity by the neoplasticlymphoid cells themselves, (b) to weakness of homeostatic control over otherself-reactive cells in neoplastic lymphoid tissue, or (c) to the release of arange of abnormal clones, possibly as a consequence of a combination ofgerminal and somatic mutation.

Submitted on December 18, 1962 Accepted on April 3, 1962