Success rate of orthograde endodontic retreatment after failed apicectomy - a retrospective study

INTRODUCTION

Orthograde retreatment after failed apicectomy maybe a treatment alternative to endodontic resurgery. The purpose of this study was to examine the clinical outcome of orthograde endodontic retreatment after failed apicectomy.

METHODOLOGY

Success was rated radiographically in 191 cases of orthograde retreatment after failed apicectomy that were treated in a private practice with a documented recall of at least 12 months. The radiographs were rated individually by two observers, in cases of disagreement a consensus was reached by joint discussion with a third observer. Success or failure were evaluated according to previously described criteria. The success rate and the median survival were calculated using the Kaplan-Meier survival analysis. The log rank test was used to evaluate the effect of prognostic factors/predictors. Hazard ratios of predictors were analyzed using Univariate Cox Proportional Hazard regression analysis.

RESULTS

The mean follow-up of the included 191 patients (124 females, 67 males) was 32.13 (± 23.68) months and the median was 25 months. The overall recall rate was 54%. Cohen Kappa analysis revealed nearly perfect agreement between both observers (k=0.81; P=1.0). The overall percentage of success was 84.82% (complete healing 79.06%, incomplete healing 5.76%). The median survival was 86 months (95% CI: 56-86). None of the selected predictors had an influence on the treatment outcome (P>0.05).

CONCLUSIONS

Orthograde retreatment should be considered a valuable treatment option after failed apicectomy. A surgical endodontic retreatment can still be a treatment option after orthograde retreatment to obtain outcome for the patient.

System impacts of the COVID-19 pandemic on New York City's emergency medical services

OBJECTIVES

To describe the impact of the COVID-19 pandemic on New York City's (NYC) 9-1-1 emergency medical services (EMS) system and assess the efficacy of pandemic planning to meet increased demands.

METHODS

Longitudinal analysis of NYC 9-1-1 EMS system call volumes, call-types, and response times during the COVID-19 peak-period (March 16-April 15, 2020) and post-surge period (April 16-May 31, 2020) compared with the same 2019 periods.

RESULTS

EMS system received 30,469 more calls from March 16-April 15, 2020 compared with March 16-April 15, 2019 (161,815 vs 127,962; P < 0.001). On March 30, 2020, call volume increased 60% compared with the same 2019 date. The majority were for respiratory (relative risk [RR] = 2.50; 95% confidence interval [CI] = 2.44-2.56) and cardiovascular (RR = 1.85; 95% CI = 1.82-1.89) call-types. The proportion of high-acuity, life-threatening call-types increased compared with 2019 (42.3% vs 36.4%). Planned interventions to prioritize high-acuity calls resulted in the average response time increasing by 3 minutes compared with an 11-minute increase for low low-acuity calls. Post-surge, EMS system received fewer calls compared with 2019 (154,310 vs 193,786; P < 0.001).

CONCLUSIONS

COVID-19-associated NYC 9-1-1 EMS volume surge was primarily due to respiratory and cardiovascular call-types. As the pandemic stabilized, call volume declined to below pre-pandemic levels. Our results highlight the importance of EMS system-wide pandemic crisis planning.

World Trade Center exposure, post-traumatic stress disorder, and subjective cognitive concerns in a cohort of rescue/recovery workers

OBJECTIVE

To determine whether World Trade Center (WTC)-exposure intensity and post-traumatic stress disorder (PTSD) are associated with subjective cognitive change in rescue/recovery workers.

METHOD

The population included 7875 rescue/recovery workers who completed a subjective cognition measure, the Cognitive Function Instrument (CFI), between 3/1/2018 and 2/28/2019 during routine monitoring, indicating whether they had experienced cognitive and functional difficulties in the past year. Higher scores indicated greater self-perceived cognitive change. Probable PTSD, depression, and alcohol abuse were evaluated by validated mental health screeners. Logistic regression assessed the associations of WTC exposure and current PTSD with top-quartile (≥2) CFI score, and of early post-9/11 PTSD with top-quartile CFI in a subpopulation (N = 6440). Models included demographics, smoking, depression, and alcohol abuse as covariates.

RESULTS

Mean age at CFI completion was 56.7 ± 7.7 (range: 36-81). Participants with high-intensity WTC exposure had an increased likelihood of top-quartile CFI score (odds ratio[OR] vs. low exposure: 1.32, 95%CI: 1.07-1.64), controlling for covariates. Current and early PTSD were both associated with top-quartile CFI (OR: 3.25, 95%CI: 2.53-4.19 and OR: 1.56, 95%CI: 1.26-1.93) respectively.

CONCLUSIONS

High-intensity WTC exposure was associated with self-reported cognitive change 17 years later in rescue/recovery workers, as was PTSD. Highly WTC-exposed subgroups may benefit from additional cognitive evaluation and monitoring of cognition over time.

Unusual Repair of Aortic Coarctation: Transcatheter Intervention Implications

A 56-year old male was evaluated for exertional dyspnea. He had previously undergone mechanical aortic valve replacement and aortic coarctation repair. Following uncomplicated coronary angiography using Judkins left and right catheters, aortography revealed that the loud murmur was related to an unusual, extra-anatomic surgical repair: transverse aorta to descending aorta bypass. Recognition of an extra-anatomic surgical bypass of coarctation is important, as this repair would leave a continuous murmur on exam.

Post-intervention coronary pseudoaneurysm treated with a covered stent

WEBSITE FEATURE

Effect of Beta-blocker therapy on survival in patients with severe mitral regurgitation and normal left ventricular ejection fraction

Chronic volume overload from chronic severe mitral regurgitation (MR) results in neuroendocrine activation similar to the heart failure syndrome despite normal left ventricular (LV) ejection fraction (EF). Hence, the hypothesis that beta-blocker (BB) therapy may have a beneficial effect in these patients was tested using a large observational cohort. Our echocardiographic database was searched for patients with severe MR and normal LVEF. Full chart reviews were conducted for clinical and pharmacologic data. Survival was analyzed as a function of BB therapy. The search produced 895 patients aged 68 +/- 17 years, 44% men, with LVEF 66 +/- 7%. Of these, 32% were on BB therapy. Use of a BB was associated with a significantly decreased mortality hazard of 0.62 (95% confidence interval 0.46 to 0.83, p = 0.002), which was unchanged after adjusting for age, gender, LVEF, coronary artery disease, diabetes mellitus, hypertension, and cardiac valve surgery. The independent beneficial effect of BBs was seen in patients with or without coronary artery disease, those with or without hypertension, and patients managed both medically and surgically. In conclusion, use of BB therapy was associated with a significant independent survival benefit in patients with chronic severe MR with normal LVEF. This benefit was seen in patients with or without coronary artery disease, as well as patients managed both medically and surgically. Use of BBs in patients with severe MR despite normal LVEF is suggested.

“Tobacco Free With FDNY”

CONTEXT

After the World Trade Center (WTC) collapse, 15% (1,767) of rescue workers from the Fire Department of the City of New York (FDNY) considered themselves to be current cigarette smokers. Post-WTC collapse, 98% reported acute respiratory symptoms, and 81% reported health concerns. Nonetheless, 29% of current smokers increased tobacco use, and 23% of ex-smokers resumed cigarette smoking.

OBJECTIVE

To determine the effect of a comprehensive tobacco-cessation program using combination tobacco-dependency treatment medications adjusted to the individual's daily tobacco use.

DESIGN

FDNY cigarette smokers enrolled in "Tobacco Free With FDNY," a no-cost quit-smoking program providing counseling, support, and medications. At the end of the 3-month treatment phase and at the 6-month and 12-month follow-up visits, abstinence rates were confirmed by expired carbon monoxide levels or by the verification of a household member.

SETTING

FDNY Bureau of Health Services between August 1, 2002 and October 30, 2002.

PARTICIPANTS

A total of 220 current cigarette smokers from the FDNY.

RESULTS

At study enrollment, the mean (+/- SD) tobacco use was 20 +/- 7 cigarettes per day, and the mean tobacco dependency, as assessed by a modified Fagerstrom test score, was 6.7 +/- 2.5 (maximum score, 10). Based on tobacco use, 20% of enrollees used three types of nicotine medications, 64% used two types, 14% used one type, and 3% used no medications. Additionally, 14% of enrollees used bupropion sustained release. The confirmed continuous abstinence rates were 47%, 36%, and 37%, respectively, after 3 months of treatment and at the 6-month and 12-month follow-up. Abstinence rates did not correlate with the history of tobacco use but correlated inversely with tobacco dependency. Adverse events and maximal nicotine medication use were unrelated, and no one experienced a serious adverse event.

CONCLUSION

Tobacco dependency treatment using combination nicotine medications is effective and safe. Future studies should consider the following: (1) both history of tobacco use and withdrawal symptoms to determine the number and dose of nicotine medications; and (2) continuing combination treatment for > 3 months.

Impact of asthma intervention in two elementary school-based health centers in the Bronx, New York City

This study examines healthcare utilization over time in Bronx, New York schoolchildren with asthma who were previously identified via parent surveys in six elementary schools. Four of the schools have on-site school-based health centers (SBHCs), and two do not have on-site health services (control schools). At baseline, we reported an asthma prevalence of 20%, and high rates of emergency department (ED) use (46%) in the previous year. To determine if asthma morbidity (specifically, ED use, community provider use, and hospitalizations for asthma) could be reduced by incorporating an aggressive intervention at two schools with SBHCs, we prospectively followed children for up to 3 years. Parents were scheduled for interviews every 6 months, and were queried about their children's use of health services for asthma in the prior 6 months. In multivariate models, children in the two intervention SBHC schools were less likely to have visited a community provider for asthma (relative rate ratio, 0.52; 95% confidence interval (CI), 0.30-0.88) or an emergency department for asthma (odds ratio, 0.44; 95% CI, 0.14-1.38; P = 0.059) in the prior 6 months compared to children attending control schools. There was no difference in community provider use or emergency department use for asthma between children attending nonintervention SBHCs and control schools. However, school type did not affect asthma hospitalization rates, which declined in all groups. Our findings support the effectiveness of aggressive school-based asthma services provided by SBHCs to reduce asthma morbidity and complement community health services.

A P450 BM-3 mutant hydroxylates alkanes, cycloalkanes, arenes and heteroarenes

P450 monooxygenases from microorganisms, similar to those of eukaryotic mitochondria, display a rather narrow substrate specificity. For native P450 BM-3, no other substrates than fatty acids or an indolyl-fatty acid derivative have been reported (Li, Q.S., Schwaneberg, U., Fischer, P., Schmid, R.D., 2000. Directed evolution of the fatty-acid hydroxylase P450BM-3 into an indole-hydroxylating catalyst. Chem. Eur. J. 6 (9), 1531-1536). Engineering the substrate specificity of Bacillus megaterium cytochrome P-450 BM3: hydroxylation of alkyl trimethylammonium compounds. Biochem. J. 327, 537-544). We thus were quite surprised to observe, in the course of our investigations on the rational evolution of this enzyme towards mutants, capable of hydroxylating shorter-chain fatty acids, that a triple mutant P450 BM-3 (Phe87Val, Leu188-Gln, Ala74Gly, BM-3 mutant) could efficiently hydroxylate indole, leading to the formation of indigo and indirubin (Li, Q.S., Schwaneberg, U., Fischer, P., Schmid, R.D., 2000. Directed evolution of the fatty-acid hydroxylase P450BM-3 into an indole-hydroxylating catalyst. Chem. Eur. J. 6 (9), 1531-1536). Indole is not oxidized by the wild-type enzyme; it lacks the carboxylate group by which the proper fatty acid substrates are supposed to be bound at the active site of the native enzyme, via hydrogen bonds to the charged amino acid residues Arg47 and Tyr51. Our attempts to predict the putative binding mode of indole to P450 BM-3 or the triple mutant by molecular dynamics simulations did not provide any useful clue. Encouraged by the unexpected activity of the triple mutant towards indole, we investigated in a preliminary, but systematic manner several alkanes, alicyclic, aromatic, and heterocyclic compounds, all of which are unaffected by the native enzyme, for their potential as substrates. We here report that this triple mutant indeed is capable to hydroxylate a respectable range of other substrates, all of which bear little or no resemblance to the fatty acid substrates of the native enzyme.

An evaluation of Open Airways for Schools: using college students as instructors

Fifteen years ago, Open Airways for Schools (OAS) was found to be an effective asthma education program for elementary school children when taught by professionals. To determine whether OAS is effective when taught by college students and whether it could withstand potential cohort effects, 54 inner-city fourth and fifth graders were taught OAS. Paired t-tests revealed that OAS improved asthma knowledge, self-efficacy, self-management skills, social support, and perception of well-being (p < 0.05). Fifteen years later OAS continues to improve children's self-management skills. Facilitators with little prior experience who received brief training in asthma knowledge and group leadership skills can effectively teach OAS.

P450 in biotechnology: zinc driven omega-hydroxylation of p-nitrophenoxydodecanoic acid using P450 BM-3 F87A as a catalyst

Cytochrome P450 enzymes require the delivery of two electrons to the heme protein for their enzymatic function. NADPH or NADH are usually used as reduction equivalents. In the absence of a substrate, NADPH may inactivate P450 enzymes. Furthermore, it is expensive, making it unsuitable for the preparative synthesis of fine chemicals. Approaches for replacing NADPH with an electrochemically generated reduction by using platinum-electrodes and different mediators are known. In the present study, NADPH was substituted by the mediator cobalt(III)sepulchrate and zinc dust that serves as an electron source. The mutated fatty acid hydroxylase P450 BM-3 F87A from Bacillus megaterium was chosen as a catalyst, since it shows a three-fold higher sensitivity and a nearly five-fold higher activity for p-nitrophenoxydodecanoic acid (12-pNCA) than the wild-type enzyme. The formation of p-nitrophenolate can easily be monitored using a photometer at 410 nm. The turnover rate of the zinc/cobalt(III)sepulchrate system reaches 20% of the NADPH activity. Compared to the electrochemical approaches the activity is at least 77% higher (turnover 125 eq min-1). The presented alternative cofactor system can be used instead of NADPH or expensive electrochemical devices (platinum electrodes) for fine chemical synthesis.

A high-density integrated genetic linkage and radiation hybrid map of the laboratory rat

The laboratory rat (Rattus norvegicus) is a key animal model for biomedical research. However, the genetic infrastructure required for connecting phenotype and genotype in the rat is currently incomplete. Here, we report the construction and integration of two genomic maps: a dense genetic linkage map of the rat and the first radiation hybrid (RH) map of the rat. The genetic map was constructed in two F2 intercrosses (SHRSP x BN and FHH x ACI), containing a total of 4736 simple sequence length polymorphism (SSLP) markers. Allele sizes for 4328 of the genetic markers were characterized in 48 of the most commonly used inbred strains. The RH map is a lod >/= 3 framework map, including 983 SSLPs, thereby allowing integration with markers on various genetic maps and with markers mapped on the RH panel. Together, the maps provide an integrated reference to >3000 genes and ESTs and >8500 genetic markers (5211 of our SSLPs and >3500 SSLPs developed by other groups). [Bihoreau et al. (1997); James and Tanigami, RHdb (http:www.ebi.ac.uk/RHdb/index.html); Wilder (http://www.nih.gov/niams/scientific/ratgbase); Serikawa et al. (1992); RATMAP server (http://ratmap.gen.gu.se)] RH maps (v. 2.0) have been posted on our web sites at http://goliath.ifrc.mcw.edu/LGR/index.html or http://curatools.curagen.com/ratmap. Both web sites provide an RH mapping server where investigators can localize their own RH vectors relative to this map. The raw data have been deposited in the RHdb database. Taken together, these maps provide the basic tools for rat genomics. The RH map provides the means to rapidly localize genetic markers, genes, and ESTs within the rat genome. These maps provide the basic tools for rat genomics. They will facilitate studies of multifactorial disease and functional genomics, allow construction of physical maps, and provide a scaffold for both directed and large-scale sequencing efforts and comparative genomics in this important experimental organism.

Glycolipid-independent sorting of a secretory glycoprotein to the apical surface of polarized epithelial cells

Proteins attached to the membrane by a glycosylphosphatidylinositol (GPI)-anchor cluster together with glycolipids in detergent-insoluble complexes at the site of sorting in the trans-Golgi network. This process has been shown to be critical for the targeting of these proteins to the apical cell surface in polarized epithelial cells. We show in this study that gp80 (clusterin), an apically secreted glycoprotein, is not included in detergent-insoluble complexes in Madin-Darby canine kidney cells. Furthermore in Fisher rat thyroid cells, which target GPI-anchored proteins preferentially to the basolateral cell surface, gp80 is secreted apically. Together these results suggest that this secretory glycoprotein and GPI-linked proteins use different mechanisms to reach the apical membrane.

Sorting of gp80 (GPIII, clusterin), a marker protein for constitutive apical secretion in Madin-Darby canine kidney (MDCK) cells, into the regulated pathway in the pheochromocytoma cell line PC12

We have studied the biogenesis and transport of a marker protein for constitutive apical secretion in Madin-Darby canine kidney (MDCK) cells, the gp80 glycoprotein complex (clusterin, apolipoprotein J, complement lysis inhibitor), in the rat pheochromocytoma cell line, PC12, by pulse-chase analysis of the endogeneously expressed complex. We demonstrate that in PC12 cells, gp80 is secreted via the regulated pathway, although sorting into that pathway is inefficient. Of the newly synthesized complex, 50% is released constitutively during a 2.5 h chase, 15% is released by depolarization-induced secretion, 35% stay associated with the cells. In contrast to their pivotal role in the constitutive apical exocytosis of the gp80 complex in MDCK cells, the N-linked carbohydrate moieties are dispensible for the sorting of this protein into the regulated pathway in PC12 cells, suggesting that distinct signals and sorting mechanisms are involved in these pathways.

Sorting of a secretory protein (gp80) to the apical surface of Caco-2 cells

We have investigated the synthesis and polarized secretion of the exogenous gp80 glycoprotein complex in the human epithelial adenocarcinoma cell line, Caco-2. gp80 is secreted at the apical surface of Madin-Darby canine kidney (MDCK) cells and should, therefore, display the signal(s) required for sorting into the apical exocytic pathway. In Caco-2 cells, no bona fide secretory protein released preferentially at the apical surface has been described so far. To address the question of whether Caco-2 cells possess a machinery capable of delivery of secretory proteins at the apical surface, we stably transfected the cells with a recombinant gene coding for the gp80 glycoprotein complex. Pulse-chase analysis showed that stably transfected Caco-2 cells secrete gp80 quantitatively into the medium. In polarized layers of filter-grown Caco-2 cells, the protein was secreted predominantly at the apical surface, demonstrating the ability of the cells to efficiently sort secretory proteins directly into the apical exocytic pathway. Our results further demonstrate that the apical targeting information of gp80 recognized by MDCK cells is also recognized by Caco-2 cells.

Molecular cloning of gp 80, a glycoprotein complex secreted by kidney cells in vitro and in vivo. A link to the reproductive system and to the complement cascade

cDNA clones coding for the gp 80 heterodimeric glycoprotein complex secreted constitutively at the apical surface of Madin-Darby canine kidney (MDCK) cells have been isolated from MDCK cDNA libraries in lambda gt11 and lambda gt10. The cloned sequences encode a polypeptide chain of 445 amino acids. The deduced amino acid sequence of the gp 80 protein reveals 80% homology to rat SGP-2, a major secretory protein of the testes epithelium and 83% homology to SP-40,40, a human complement-associated protein. SGP-2 and SP-40,40 have been proposed to be serum and seminal forms of the same protein. The sequence homology as well as the results of Southern and Northern blot analyses and immunological studies suggest that gp 80 is the canine homolog of the rat SGP-2 and the human SP-40,40. The protein is expressed in the embryonic kidney already early during organogenesis. In the adult kidney the protein has been localized along the luminal surfaces of the proximal and distal tubule and the collecting duct cells.

Epinephrine improves expiratory flow rates in patients with asthma who do not respond to inhaled metaproterenol sulfate

One hundred patients with acute asthma and peak expiratory flow rates (PEFR) less than 150 L/min were randomized and treated in a double-blind treatment protocol with either metaproterenol sulfate aerosol (MPA) inhalation and placebo injection or epinephrine injection (EPI) and inhaled placebo at entry and at 30 and 60 minutes, and then were treated with the crossover comparison regimen at 120, 150, and 180 minutes. The two groups had similar entry PEFRs and FEV1 (MPA, 112 L/min; 0.94 L, respectively; EPI, 111 L/min; 0.85 L, respectively) and similar plasma theophylline levels (MPA, 12.2 micrograms/ml; EPI, 13.8 micrograms/ml). PEFR and FEV1 were measured every 30 minutes for 4 hours. Mean expiratory flow rates among both groups were similar at entry and at 120 and 240 minutes. At 120 minutes, flow rates had improved in 28/46 MPA-treated patients (61%) and 48/54 EPI-treated patients (89%). Among these improved patients, flow rates were significantly higher in the MPA-treated group. At 120 minutes, 18/46 MPA-treated patients (39%) and 6/54 EPI-treated patients (11%) had PEFRs less than 120 L/min and PEFR and FEV1 less than 120% of baseline values (p less than 0.01). In 13 of these 18 MPA-treated patients who did not improve compared to 1/6 EPI-treated patients who did not improve, PEFRs were greater than 120 L/min, and PEFR and FEV1 had increased 20% or more above baseline values after treatment with the crossover comparison regimen (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of atropine sulfate and metaproterenol sulfate in the emergency treatment of asthma

Twenty-one patients presenting to an emergency room with moderate to severe asthma were entered into the following double-blind, crossover study. First, patients inhaled twice at 30-min intervals either atropine sulfate (AS) (3.2 mg and 3.2 mg; total dose, 6.4 mg) or metaproterenol sulfate (MP) (15 mg and 15 mg; total dose, 30 mg). Then after 80 min (crossover), they inhaled either AS (3.2 mg) or MP (15 mg). FEV1 was measured before treatment and at 30, 40, 70, 80, 110, and 120 min after the start of the study. FEV1 from 20 patients who completed the protocol were compared (Student's paired t test), and the values are presented as mean +/- SEM. Both groups began with equally severe airways obstruction (AS versus MP: 1.02 +/- 0.07 L and 0.92 +/- 0.15 L, respectively; p greater than 0.05). After 120 min, when all had received both medications, FEV1 had improved significantly and similarly among both groups, indicating that initially they had equivalent bronchodilator capacities. Atropine sulfate produced small but significant changes in FEV1 at 30 and 70 min, but not at 80 min nor after crossover. In contrast, MP both alone and after crossover significantly improved FEV1. The difference in improvement among the groups was significant at 80 min and after crossover. Atropine sulfate produced multiple adverse effects in all patients. We conclude that during acute severe asthma, AS (6.4 mg) does not produce clinically significant bronchodilation either alone or in combination with MP.

Bullous pulmonary damage in users of intravenous drugs

Among a large group of users of illicit intravenous drugs, the incidence of bullous pulmonary damage was noted to be 2 percent (6/387). Bullous damage was significantly different in the drug users than in those who did not use drugs. The drug users were significantly younger than the nonusers, their bullae were large and confined to the upper lobes, and alpha 1-antitrypsin deficiency was very unlikely. These features strongly implicate intravenous drug abuse in the pathogenesis of these patients' bullous pulmonary damage.

Diaphragm fatigue induced by inspiratory resistive loading in spontaneously breathing rabbits

Diaphragmatic contractility was assessed in spontaneously breathing ketamine-anesthetized rabbits by measuring the strength of diaphragmatic contraction in response to bilateral supramaximal phrenic nerve stimulation at frequencies between 10 and 100 Hz. During 10-180 min of inspiratory resistive loading, contractility decreased by approximately 40%, and hypoxemia and both respiratory and lactic acidosis developed. After 10 min of recovery, both the response to high-frequency stimulation (100 Hz) and the arterial PO2 and PCO2 returned to base-line levels, whereas metabolic acidosis and reduced response to low-frequency stimulation (10-20 Hz) persisted. Similar levels of hypoxemia and respiratory acidosis in the absence of inspiratory resistive loading did not alter diaphragmatic contractility. We conclude that in anesthetized rabbits excessive inspiratory resistive loading results in partially reversible diaphragm fatigue of the high- and low-frequency types, accompanied by hypoventilation and lactic acidosis.

Lactic acidosis in severe asthma

Twelve patients with severe asthma in whom lactic acidosis developed are presented. All had an arterial blood pH level lower than that expected for the measured partial pressure of arterial carbon dioxide, all had an abnormally large anion gap, and the blood lactate level exceeded 2.8 mmol/liter. Respiratory acidosis subsequently developed in eight patients, and six required intubation. Lactic acidosis can develop in patients with severe asthma. Such patients are in danger of the development of respiratory failure and must be treated vigorously and observed closely.