Thermistor Guided Radiofrequency Ablation of Atrial Insertion Sites in Patients with Accessory Pathways

Radiofrequency ablation has gained acceptance in the treatment of patients with symptomatic Wolff-Parkinson-White syndrome. The purpose of this study was to characterize the relation between temperature and other electroconductive parameters in patients undergoing atrial insertion accessory pathway ablation utilizing a thermistor equipped catheter. The mean temperature and power at sites of atrial insertion ablation are lower than has been previously associated with creation of radiofrequency lesions in the ventricle. While high cavitary blood flow in the atrium may result in cooling, the thinner atrial tissue may require less energy to achieve adequate heating than ventricular myocardium.     

Prevention of Human Recombinant Intei leukin-1β (rhIL-1β) Embryolethality with Progesterone or Indomethacin

PROBLEM : Bropirimine and tilorone were found in earlier studies to be embryolethal when administered to Crl:TUC(SD)spf (TUC) rats on gestation day 10. Progesterone or indomethacin could, at least partially, prevent this effect. The immunomodulators appeared to mimic the luteolytic effects of PGF_2α, resulting in a shutdown in progesterone release by the corpora lutea, followed by a disruption in maternal support to the pregnant uterus and embryolethality. Since bropirimine has been shown to induce interleukin-1, and since this cytokine has been found to increase PGF2_α levels in human decidual cells, the decision was made to investigate whether human interleukin-1β might act in an analogous manner to bropirimine and tilorone. METHOD : Bropirimine (400 mg/kg, p.o.) or rhIL-1β (20, 30, or 40 μg/kg, s.c.) was administered on gestation day 10 to Crl:CD[BR] (CD) or TUC rats, alone and in combination with progesterone (2 mg/kg/day, s.c.) or indomethacin (0.6 mg/day, s.c, days 9–11). On gestation day 14 the dams were killed and their uterine contents examined. RESULTS : rhIL-1β (30–40 μg/kg) was embryolethal when administered to CD or TUC rats on gestation day 10. Progesterone or indomethacin coadministration prevented, at least partially, the embryolethality seen when rhIL-1β was administered (30 μg/kg) to TUC rats. CONCLUSION : Evidence was obtained in support of the hypothesis that interleukin-1 is involved in the embryolethal actions of the immunomodulators bropirimine and tilorone.     

Biochemical responses to sediment-associated contaminants in brown bullhead (Ameriurus nebulosus) from the Niagara River ecosystem

Brown bullhead (Ameriurus nebulosus) were collected from three sites in the Niagara River ecosystem in June and September of 1991, and sediment samples from these sites were obtained in July 1991. The sites were located in the Buffalo River, the Niagara River adjacent to the Love Canal dump site, and in Black Creek, a Canadian tributary of the Niagara River which served as a reference site. Sediment samples from these sites contained measurable concentrations of various polycyclic aromatic hydrocarbons (PAHs) and chlorinated hydrocarbons (CHs). However, the Buffalo River and Love Canal samples were significantly more contaminated than those from Black Creek. Moreover, Buffalo River samples contained greater PAH concentrations than samples from the Love Canal, while the reverse was observed for CHs. Bile and liver of bullhead were used for the following analyses: fluorescent aromatic compounds in bile, a measure of exposure to PAHs, microsomal cytochrome P450 (CYP) and P450IA (CYP1A) contents and ethoxyresorufin-O-deethylase (EROD) activities, total glutathione (TH-GSH) concentrations, concentrations of 8- oxodeoxyguanosine (8-oxo-dG), and concentrations of hydrophobic DNA adducts (as measured by 32P-postlabelling). Additionally, a laboratory experiment was performed to examine CYP1A-associated responses in bullhead exposed to the model inducer, - naphthoflavone (BNF). Results from the laboratory induction study were generally consistent with those observed in the field study, but the field study results suggested induction of CYP1A in bullhead from the reference site (Black Creek). For both field collections, fish from the Buffalo River displayed the greatest concentrations of fluorescent compounds in bile and hepatic DNA adducts, whilst fish from the Love Canal site displayed the greatest microsomal CYP1A concentrations and EROD activities. TH- GSH concentrations were significantly greater in Buffalo River fish versus Black Creek only for the June sampling. No statistically significant differences in 8-oxo-dG concentrations in bullhead hepatic DNA were observed among the sites at either sampling date. The different patterns in biochemical responses observed were consistent with sediment chemistries, and these results suggest that exposure of feral teleosts to different suites of bioavailable contaminants can be associated with expression of a characteristic array of biochemical responses     

Catheter Ablation of the Atrioventricular Junction Using a Helical Microwave Antenna: A Novel Means of Coupling Energy to the Endocardium

Catheter ablation with either direct current defibrillator discharges or radiofrequency energy produces tissue injury via current flow from an electrode into the adjacent myocardium. In order to affect tissue at a distance, excessive power density may be produced at the electrode-tissue interface with the possibility of explosive gas formation or coagulum formation. A novel microwave catheter was developed with a helical antenna distally. This coil, although not in direct contact with the endocardium, radiates an electromagnetic field into the tissue that, in turn, causes thermal injury. The utility of this system for ablation was assessed in six dogs. The antenna catheter was introduced percutaneously and positioned so as to record the largest His electrogram. Microwave power (50 watts at 2,450 MHz) was applied for 114 +/- 118 seconds. Complete AV block was produced in all six animals with 1.8 +/- 1.2 applications. There was no ventricular ectopy or change in blood pressure during microwave ablation. One dog died 6 days after ablation. The remaining five dogs had persistent, complete AV block during 6 weeks of follow-up. Pathological analysis at 6 weeks revealed a large (mean 2.8 x 4.7 mm) fibrovascular scar in the region of the AV junction. Percutaneous microwave ablation of the endocardium appears feasible. By radiating an electromagnetic field without direct contact, this system can produce large lesions without being limited by desiccation of tissue and impedance rise.     

High Vegetable and Fruit Diet Intervention in Premenopausal Women with Cervical Intraepithelial Neoplasia

OBJECTIVE: To examine whether diet intervention can promote increased vegetable and fruit intake, as reflected in increased plasma carotenoid and decreased plasma total homocysteine concentrations, in premenopausal women with cervical intraepithelial neoplasia, a precancerous condition. DESIGN: Randomized controlled diet intervention study. SUBJECTS: Fifty-three free-living premenopausal women who had been diagnosed with cervical intraepithelial neoplasia, were randomly assigned to an intervention (n = 27) or a control (n = 26) group. INTERVENTION: Individualized dietary counseling to increase vegetable and fruit intake. MAIN OUTCOME MEASURES: Diet was assessed by food frequency questionnaire. Plasma carotenoids and total homocysteine were measured at enrollment and at 6 months follow up. ANALYSIS: Associations between baseline plasma concentrations of carotenoids and homocysteine and influencing factors were examined with multiple regression analysis. Repeated measures analysis of variance was used to test for group by time effects in these plasma concentrations. Plasma carotenoids at baseline and 6 months in the study groups, and differences in homocysteine concentrations from baseline to 6 months, were compared with independent sample t tests. RESULTS: Repeated measures analysis of variance showed significant group by time effects (P<.01) in plasma carotenoid and homocysteine concentrations. In the intervention group, total plasma carotenoids increased by an average of 91%, from 2.04+/-0.13 (mean+/-standard error of the mean) to 3.90+/-0.56 micromol/L and plasma total homocysteine was reduced by 11%, from 9.01+/-0.40 to 8.10+/-0.44 micromol/L (P<.003). Neither changed significantly in the control group. APPLICATIONS: Individualized dietary counseling can effectively promote increased vegetable and fruit intake in premenopausal women. This dietary pattern may reduce risk for cancer and other chronic diseases and also promote an improvement in folate status.     

Long-term Stability of Endocardial Left Ventricular Pacing Leads Placed via the Coronary Sinus

Background: Left ventricular endocardial pacing leads placed via the coronary sinus (CS) are increasingly implanted to achieve cardiac resynchronization therapy (CRT); however, the long-term stability of these leads is unknown. We sought to determine the implant success and long-term stability of CS leads in our single center experience.
Methods: All consecutive patients who underwent CRT via implantation of the CS lead between January 1999 and December 2005 were included. Pacing thresholds at implant and during long-term follow-up were reviewed and the rate of acute (within 24 hours of implant) and chronic (>24 hours) lead failure was determined.
Results: A total of 512 patients (mean age 68 ± 12 years; 409 [80%] male) underwent CRT device implantation and were included. The CS lead implantation was successful on the initial implantation in 487 patients (95%) and subsequently successful in six patients (24%) in whom initial attempts were unsuccessful. Acute lead failure occurred in 25 patients (5.1%) and was most commonly due to persistent extra-cardiac stimulation. The rate of chronic lead failure was 4% in the first year and remained stable during long-term follow-up. The CS lead pacing thresholds remained stable with only minimal increase (1.42 ± 0.85 V/0.42 ± 0.25 ms vs 1.51 ± 1.05 V/0.47 ± 0.29 ms; P = 0.04).
Conclusions: Placement of a left ventricular pacing lead via the CS is feasible and safe in the vast majority of patients. Once placed, the CS leads remain stable with excellent pacing thresholds over the longer term.     

LACK OF ASSOCIATION OF PROSTATE CARCINOMA NUCLEAR GRADING WITH PROSTATE SPECIFIC ANTIGEN RECURRENCE AFTER RADICAL PROSTATECTOMY

PURPOSE: Grading prostate cancer using the Gleason system relies only on architectural tumor growth, in contrast to other systems, such as the WHO system, which grade prostate carcinoma based on nuclear features as well as architectural patterns. The prognostic significance of nuclear grading remains controversial since most studies were performed before prostate specific antigen (PSA) screening became widely available. We evaluated the significance of nuclear grade for predicting PSA recurrence in a contemporary cohort of patients treated with radical prostatectomy for clinically localized prostate carcinoma. MATERIALS AND METHODS: Nuclear grades 1 to 3 were determined in 141 consecutive radical prostatectomies in 1995. Predominant and worst nuclear grade was determined by a consensus of 3 pathologists. Statistical analysis compared nuclear grade with Gleason score using the chi-square test. The Cox proportional hazards analysis was performed to calculate the ability of nuclear grade, Gleason score and other variables to predict PSA recurrence. RESULTS: We identified a significant association of Gleason score with worst nuclear grade (p = 0.007). All 6 cases with a Gleason score of 8 or greater had a worst nuclear grade of 3, in contrast to 36 of 60 (60%) with a score 6 or less, in which the worst nuclear grade was 3. Of the 141 patients 31 (21.9%) had PSA recurrence at a median followup of 3.7 years. The univariate Cox model revealed significant associations of PSA recurrence with Gleason score 8 or greater (hazards ratio 5.5, p = 0.005), extraprostatic extension (hazards ratio 3.4, p = 0.001), positive surgical margin (hazards ratio 2.6, p = 0.009), seminal vesicle involvement (hazards ratio 7.3, p <0.001), preoperative serum PSA (hazards ratio 1.03, p = 0.007), tumor stage (hazards ratio 3.6, p = 0.001) and maximal tumor dimension (hazards ratio 2.4, p <0.001). However, overall and worst nuclear grade did not predict PSA recurrence (p = 0.89 and 0.13, respectively). Nuclear grade did not fit any multivariate model tested, which otherwise included Gleason score, log(PSA), surgical margin status, extraprostatic extension, seminal vesicle status, tumor size and pathological stage. By varying sample fixation time we also showed that benign prostate tissue in the same section as prostate carcinoma had grade 2 or 3 nuclear changes, that is moderate to marked anaplasia. CONCLUSIONS: High nuclear grade is associated with high Gleason score. However, prostate carcinoma with a Gleason score of 6 or less shows extreme variability. Nuclear grade determined by light microscopy failed to predict PSA recurrence in a contemporary series of men with clinically localized prostate cancer treated with radical prostatectomy. Nuclear morphology is subject to tissue fixation and processing artifact. Any nuclear morphometric study must consider this artifact.     

CRP gene variation and risk of community-acquired pneumonia

Background and objective: CRP has several potentially antibacterial effects, and variation in the CRP gene is known to influence CRP levels. Whether this variation influences risk of infection, and hence whether CRP has anti‐infective activity in humans, is uncertain. Methods: We evaluated a series of haplotype‐tagging single nucleotide polymorphisms among 5374 individuals in the Cardiovascular Health Study, a cohort of older adults from four communities, who were followed for community‐acquired pneumonia for 12–13 years. Secondarily, we evaluated whether these polymorphisms varied among men in the Health Professionals Follow‐up Study who self‐reported pneumonia on biennial questionnaires. Results: There were 581 (507 white and 74 black) Cardiovascular Health Study participants with incident hospitalizations for pneumonia. No single nucleotide polymorphism or haplotypes were associated with risk among white Cardiovascular Health Study participants. Among black participants, the haplotype tagged by A790T was associated with lower risk of incident pneumonia (hazard ratio 0.5; 95% confidence interval: 0.3–0.9) and with higher CRP levels. In Health Professionals Follow‐up Study, a separate haplotype was associated with less frequent self‐reported pneumonia but not with circulating CRP levels. Conclusions: Some genetic variants in CRP may be associated with risk of pneumonia, but haplotypes associated with risk are variably associated with baseline CRP levels. If CRP is a relevant component of innate immunity in humans, the inducibility or tissue‐specificity of expression may be at least as important as chronic circulating levels.     

A longitudinal study of enuresis from five to nine years

The prevalence of primary and secondary enuresis was examined longitudinally in a large sample of New Zealand children at ages 5, 7, and 9 years. While the prevalence of primary enuresis fell over time, secondary enuresis increased in prevalence between 5 and 7 years. There were no sex differences. An examination of some of the developmental and background characteristics of the sample indicated that enuresis was not associated with neurodevelopmental delay or 'psychosocial' factors. However, there were strong, long term associations between secondary enuresis and behavioural deviance. The behavioural results suggested that behaviour problems did not arise as a consequence of enuresis, but rather preceded it.