Cell Type-Specific Decomposition of Gingival Tissue Transcriptomes.

Genome-wide transcriptomic analyses in whole tissues reflect the aggregate gene expression in heterogeneous cell populations comprising resident and migratory cells, and they are unable to identify cell type-specific information. We used a computational method (population-specific expression analysis [PSEA]) to decompose gene expression in gingival tissues into cell type-specific signatures for 8 cell types (epithelial cells, fibroblasts, endothelial cells, neutrophils, monocytes/macrophages, plasma cells, T cells, and B cells). We used a gene expression data set generated using microarrays from 120 persons (310 tissue samples; 241 periodontitis affected and 69 healthy). Decomposition of the whole-tissue transcriptomes identified differentially expressed genes in each of the cell types, which mapped to biologically relevant pathways, including dysregulation of Th17 cell differentiation, AGE-RAGE signaling, and epithelial-mesenchymal transition in epithelial cells. We validated selected PSEA-predicted, differentially expressed genes in purified gingival epithelial cells and B cells from an unrelated cohort (n = 15 persons), each of whom contributed with 1 periodontitis-affected and 1 healthy gingival tissue sample. Differential expression of these genes by quantitative reverse transcription polymerase chain reaction corroborated the PSEA predictions and pointed to dysregulation of biologically important pathways in periodontitis. Collectively, our results demonstrate the robustness of the PSEA in the decomposition of gingival tissue transcriptomes and its ability to identify differentially regulated transcripts in particular cellular constituents. These genes may serve as candidates for further investigation with respect to their roles in the pathogenesis of periodontitis.

FoxO1-dependent induction of acute myeloid leukemia by osteoblasts in mice.

Osteoblasts, the bone forming cells, affect self-renewal and expansion of hematopoietic stem cells (HSCs), as well as homing of healthy hematopoietic cells and tumor cells into the bone marrow. Constitutive activation of ß-catenin in osteoblasts is sufficient to alter the differentiation potential of myeloid and lymphoid progenitors and to initiate the development of acute myeloid leukemia (AML) in mice. We show here that Notch1 is the receptor mediating the leukemogenic properties of osteoblast-activated ß-catenin in HSCs. Moreover, using cell-specific gene inactivation mouse models, we show that FoxO1 expression in osteoblasts is required for and mediates the leukemogenic properties of ß-catenin. At the molecular level, FoxO1 interacts with ß-catenin in osteoblasts to induce expression of the Notch ligand, Jagged-1. Subsequent activation of Notch signaling in long-term repopulating HSC progenitors induces the leukemogenic transformation of HSCs and ultimately leads to the development of AML. These findings identify FoxO1 expressed in osteoblasts as a factor affecting hematopoiesis and provide a molecular mechanism whereby the FoxO1/activated ß-catenin interaction results in AML. These observations support the notion that the bone marrow niche is an instigator of leukemia and raise the prospect that FoxO1 oncogenic properties may occur in other tissues.

Lung adenocarcinoma invasion in TGFbetaRII-deficient cells is mediated by CCL5/RANTES.

Recently, we identified a lung adenocarcinoma signature that segregated tumors into three clades distinguished by histological invasiveness. Among the genes differentially expressed was the type II transforming growth factor-beta receptor (TGFbetaRII), which was lower in adenocarcinoma mixed subtype and solid invasive subtype tumors compared with bronchioloalveolar carcinoma. We used a tumor cell invasion system to identify the chemokine CCL5 (RANTES, regulated on activation, normal T-cell expressed and presumably secreted) as a potential downstream mediator of TGF-beta signaling important for lung adenocarcinoma invasion. We specifically hypothesized that RANTES is required for lung cancer invasion and progression in TGFbetaRII-repressed cells. We examined invasion in TGFbetaRII-deficient cells treated with two inhibitors of RANTES activity, Met-RANTES and a CCR5 receptor-blocking antibody. Both treatments blocked invasion induced by TGFbetaRII knockdown. In addition, we examined the clinical relevance of the RANTES-CCR5 pathway by establishing an association of RANTES and CCR5 immunostaining with invasion and outcome in human lung adenocarcinoma specimens. Moderate or high expression of both RANTES and CCR5 was associated with an increased risk for death, P=0.014 and 0.002, respectively. In conclusion, our studies indicate RANTES signaling is required for invasion in TGFbetaRII-deficient cells and suggest a role for CCR5 inhibition in lung adenocarcinoma prevention and treatment.

Can pediatric residents interpret electrocardiograms?

The purpose of this study was to assess the electrocardiogram (ECG) interpretation skills of pediatric residents in a controlled environment and determine if the level of residency training (intern vs senior) improves accuracy. A list of ECG diagnoses was provided to four pediatric residency educators with instructions to categorize each diagnosis as follows: I, all residents; II, the majority of residents, including all senior residents; III, less than the majority of residents; and IV, few residents should be able to interpret correctly. Only those categories that the entire panel believed all residents (category I) or all senior residents (category II) should be able to interpret correctly were included. The test included 17 ECGs: 14 category I and 3 category II. A total of 132 residents participated: 78 interns and 54 seniors. Both groups scored below expected levels. Mean correct score among seniors was 10.9 out of the expected 17 (p < 0.001). Mean correct score for interns was 7.7 out of the expected 14 (p < 0.00l). No difference in ECG interpretation accuracy was found between residency programs. In general, pediatric residents' ECG interpretation skills are less accurate than expected. Although there is a trend toward improvement during training, senior residents fell short of the expectations of the panel. We speculate that focused education in this area will improve resident ECG interpretation and benefit patient care by (1) facilitating referral and treatment of patients with cardiovascular disease and (2) decreasing referrals for erroneous interpretations.

Long-term follow-up of arrhythmias in pediatric orthotopic heart transplant recipients: incidence and correlation with rejection.

BACKGROUND: Arrhythmias in adult orthotopic heart transplant (OHT) recipients are common and have been used as predictors of rejection. Because of the paucity of information in pediatric OHT recipients, the purpose of this study was to determine the incidence and correlation of arrhythmias with rejection or with coronary artery disease (CAD) in children. METHODS: We retrospectively reviewed the records, electrocardiograms (ECGs), and 24-hour ambulatory ECGs of patients who underwent OHT from January 1984 to December 1999. We excluded arrhythmias occurring in the first 2 weeks after OHT. RESULTS: Sixty-nine patients underwent OHT, received triple-immunosuppression therapy, were discharged home, and have been followed for a mean of 4.7 years (0.3-13 years). Each patient had an average of 10 ECGs and three 24-hour ECGs. Twenty-six patients had 33 arrhythmias: sinus bradycardia (n = 9), atrial tachycardia (n = 9), ventricular tachycardia (n = 3), and Wenckebach periodicity (n = 6). Sinus bradycardia was treated with theophylline in 8 patients, and 2 required pacemakers. Atrial tachycardias (atrial flutter in 4 patients and atrial ectopic tachycardia in 5) were treated with digoxin, propranolol, or procainamide. Ventricular tachycardia was treated with mexiletine, lidocaine, and amiodarone. There were 65 episodes of rejection, 20 of which were moderate/severe (> or =3B). Only Wenckebach was associated with the presence of either rejection or CAD (p < 0.05). CONCLUSIONS: We noted clinically significant arrhythmias in 38% of the pediatric OHT recipients. Sinus bradycardia, atrial tachyarrhythmias, and ventricular tachycardia occurred with the same frequency. Only new-onset Wenckebach periodicity was noted in the presence of either CAD or rejection. No arrhythmia was of negative predictive value for rejection or CAD. From this data, we suggest that new-onset Wenckebach prompt evaluation for rejection or CAD.

The emergency department versus the computer: which is the better electrocardiographer?

Electrocardiograms (ECGs) are frequently ordered in the pediatric emergency department (ED). Pediatric cardiologists are generally not asked to interpret every ECG; thus, ED patient management is often guided by the ED physicians' ECG interpretation. The objective of this study was to analyze the accuracy of ECG interpretation by ED physicians and a computer-generated interpretation and compare the two. A 12-month prospective study was performed in a pediatric ED. All patients (<22 years) who had an ECG in the ED were included. The ED physicians and the computer interpretation were compared to a reference standard. Each electrocardiographic diagnosis, as well as the ECG as a whole, was assigned to one of the following predetermined classes: I, normal sinus rhythm; II, minimal clinical significance; III, indeterminate clinical significance; IV, those of definite clinical significance. Both groups correctly interpreted all normal (class I) ECGs. The computer correctly interpreted approximately 75% of the class II and class III ECGs, whereas the ED physicians correctly interpreted 36% of both groups. For the class IV ECGs, both the computer and the ED physicians performed poorly, correctly interpreting just 14% and 28%, respectively. The computer proved to be more accurate than the ED physicians in interpreting ECGs of less than critical significance (classes II and III), but neither group was able to correctly interpret even a simple majority of the most significant abnormalities (class IV). We speculate that distributing the computer-generated interpretation to the ED physicians and formal review of all ED ECGs by a skilled interpreter may decrease the number of missed diagnoses.

Use of intravenous amiodarone for postoperative junctional ectopic tachycardia in children.

To assess the efficacy and safety of intravenous (IV) amiodarone for the treatment of postoperative junctional ectopic tachycardia (JET) in children, we retrospectively reviewed 11 patients treated with IV amiodarone for JET between 1/92 and 2/00. Data included heart rate and hemodynamics pre- and post-amiodarone, drug dosage, duration of therapy, and effect. Success was defined as reversion to sinus rhythm or slowing to a hemodynamically stable rate. The mean heart rate prior to amiodarone was 203 bpm, and the mean systolic blood pressure was 64 mmHg. Mean IV amiodarone loading dose was 8.2 +/- 4.0 mg/kg, followed by an infusion in 7 patients at a dose of 12.9 +/- 3.9 mg/kg/day for a duration of 74.3 +/- 46.9 hours. At 1 hour post-load, mean heart rate was 147 bpm and mean systolic blood pressure was 88 mmHg for the group. Three patients were in sinus rhythm, 4 in intermittent sinus rhythm with accelerated junctional rhythm, and 4 patients solely accelerated junctional rhythm. Control of JET persisted in 9 patients. Of the two patients requiring additional treatment, both had received a 5 mg/kg load and neither was on an infusion. Five patients were paced at some point following amiodarone: four to improve hemodynamics and one for late sinus bradycardia. Side effects included hypotension with loading (1) and late sinus bradycardia (1). One patient was discharged on oral amiodarone. Intravenous amiodarone given in doses of 10 mg/kg in two 5 mg/kg increments, followed by an infusion of 10-15 mg/kg/day for 48-72 hours, appears to be safe and effective for postoperative JET in patients who fail conventional therapy or who are hemodynamically unstable. Long-term oral therapy is usually not necessary.

Hearing preservation in patients with vestibular schwannomas with sudden sensorineural hearing loss.

OBJECTIVE: We evaluated hearing outcomes in patients with sudden hearing loss and vestibular schwannoma who underwent a hearing preservation operation for tumor resection in an effort to determine whether a history of sudden sensorineural hearing loss has an impact on subsequent hearing preservation surgery. METHODS: Retrospective chart review of 45 patients operated between 1990 and 1998. Patients were divided into "Recovery" (n = 22) and "No Recovery" (n = 23) groups based on preoperative hearing recovery. Hearing preservation was assessed using the AAO-HNS hearing classification system. RESULTS: Measurable hearing was preserved in 73% of patients, with 47% having good postoperative hearing (AAO-HNS Classes A-B). There was no significant difference in hearing outcome from patients presenting with progressive hearing loss (45% Classes A-B). There was also no difference in postoperative hearing between the "Recovery" and "No Recovery" groups. CONCLUSIONS: Patients with sudden hearing loss and vestibular schwannoma have the same chance of hearing preservation after tumor removal as those with progressive loss. Preoperative recovery of hearing is not predictive of hearing preservation. Available data support the nerve compression theory as the mechanism of sudden hearing loss in patients with vestibular schwannoma.

Early proactive management of vestibular schwannomas in neurofibromatosis type 2.

OBJECTIVE: The treatment of patients with neurofibromatosis Type 2 has always been challenging for neurosurgeons and neurotologists. Guidelines for appropriate management of this devastating disease are controversial. METHODS: A retrospective study of 28 patients with neurofibromatosis Type 2 who underwent 40 middle fossa craniotomies for excision of their acoustic tumors is reported. Eleven patients underwent bilateral procedures. The study focused on hearing preservation and facial nerve results for this group of patients. The 16 male patients and 12 female patients ranged in age (at the time of surgery) from 10 to 70 years, with a mean age of 22.6 years. The mean tumor size was 1.1 cm (range, 0.5-3.2 cm), and the majority of tumors were less than 1.5 cm. RESULTS: Measurable hearing was preserved in 28 ears (70%), with 42.5% being within 15 dB pure-tone average and 15% speech discrimination score of preoperative levels. In 55% of cases there was no change in the hearing class, as defined by the American Academy of Otolaryngology-Head and Neck Surgery. Of the 11 patients who underwent bilateral operations, 9 (82%) retained some hearing bilaterally. After 1-year follow-up periods (mean, 12.8 mo), 87.5% of patients exhibited normal facial nerve function (House-Brackmann Grade I). CONCLUSION: Early surgical intervention to treat acoustic tumors among patients with neurofibromatosis Type 2 is a feasible treatment strategy, with high rates of hearing and facial nerve function preservation.

Sertraline versus imipramine to prevent relapse in chronic depression.

BACKGROUND: Chronic depressions are common, disabling and under-treated, and long-term treatment is little studied. We report the continuation phase results from a long-term treatment study. METHODS: After 12 weeks of acute phase treatment in a double-blind, randomized, parallel-group, multi-center trial of sertraline or imipramine, patients with chronic depression (> or = 2 years in major depression, or major depression superimposed on dysthymia) continued study drug for 16 weeks. Initially, 635 patients were randomized to sertraline or imipramine in a 2:1 ratio. Nonresponders after 12 weeks entered a 12-week double-blind crossover trial of the alternate medication. Entry into continuation treatment required at least a satisfactory response (partial remission) to initial or crossover treatment. RESULTS: Of 239 acute or crossover responders to sertraline, 60% entered continuation in full remission and 40% with a partial remission. These proportions were identical for imipramine patients (n = 147). For both drug groups, over two-thirds of those entering in full remission retained it. For those entering in partial remission, over 40% achieved full remission. Patients requiring crossover treatment were less likely to maintain or improve their response during continuation treatment. The two drugs did not differ significantly in response distribution, drop out rates or discontinuation due to side effects during continuation treatment. LIMITATIONS: The absence of a placebo group constrains interpretation of our results, but chronic depressions have low placebo response rates. CONCLUSIONS: Most chronic depression patients who remit with 12 weeks of sertraline or imipramine treatment maintain remission during 16 weeks of continuation treatment. Most patients with a satisfactory therapeutic response (partial remission) after 12 weeks of treatment maintain it or further improve. Patients treated with imipramine experienced more side effects, but both drugs were well tolerated.

Use of tissue plasminogen activator in a stroke after radiofrequency ablation of a left-sided accessory pathway.

We describe the case of a 12-year-old girl who had a thromboembolic stroke after radiofrequency ablation of a left posterior accessory pathway involving a transseptal procedure. Symptoms of a stroke occurred 7 hours 15 minutes after completion of the procedure. Tissue plasminogen activator (tPA) was given 2 hours 30 minutes after the onset of symptoms, with complete resolution of her neurologic symptoms. No adverse effects from the tPA were seen. Because of the late onset of symptoms in this case, overnight in-hospital observation is warranted for patients who undergo radiofrequency ablation of a left-sided accessory pathway or an accessory pathway in a patient with the ability to shunt right to left. In this case, tPA was an effective and safe drug to use following a cerebral thromboembolic event occurring after a cardiac catheterization procedure.

Congenital heart block: development of late-onset cardiomyopathy, a previously underappreciated sequela.

OBJECTIVE: We report 16 infants with complete congenital heart block (CHB) who developed late-onset dilated cardiomyopathy despite early institution of cardiac pacing. BACKGROUND: Isolated CHB has an excellent prognosis following pacemaker implantation. Most early deaths result from delayed initiation of pacing therapy or hemodynamic abnormalities associated with congenital heart defects. METHODS: A multi-institutional study was performed to identify common clinical features and possible risk factors associated with late-onset dilated cardiomyopathy in patients born with congenital CHB. RESULTS: Congenital heart block was diagnosed in utero in 12 patients and at birth in four patients. Ten of 16 patients had serologic findings consistent with neonatal lupus syndrome (NLS). A pericardial effusion was evident on fetal ultrasound in six patients. In utero determination of left ventricular (LV) function was normal in all. Following birth, one infant exhibited a rash consistent with NLS and two had elevated hepatic transaminases and transient thrombocytopenia. In the early postnatal period, LV function was normal in 15 patients (shortening fraction [SF] = 34 +/- 7%) and was decreased in one (SF = 20%). A cardiac pacemaker was implanted during the first two weeks of life in 15 patients and at seven months in one patient. Left ventricular function significantly decreased during follow-up (14 days to 9.3 years, SF = 9% +/- 5%). Twelve of 16 patients developed congestive heart failure before age 24 months. Myocardial biopsy revealed hypertrophy in 11 patients, interstitial fibrosis in 11 patients, and myocyte degeneration in two patients. Clinical status during follow-up was guarded: four patients died from congestive heart failure; seven required cardiac transplantation; one was awaiting cardiac transplantation; and four exhibited recovery of SF (31 +/- 2%). CONCLUSIONS: Despite early institution of cardiac pacing, some infants with CHB develop LV cardiomyopathy. Patients with CHB require close follow-up not only of their cardiac rate and rhythm, but also ventricular function.

Recommendations for extraction of chronically implanted transvenous pacing and defibrillator leads: indications, facilities, training. North American Society of Pacing and Electrophysiology Lead Extraction Conference Faculty.

The procedure of lead removal has recently matured into a definable, teachable art with its own specific tools and techniques. It is now time to recognize and formalize the practice of lead removal according to the current methods of medicine and the health care industry. In addition, since at this time the only prospective scientific study of lead extraction is the PLEXES trial, we suggest that studies relating to the techniques of and indications for lead extraction be designed. Recommendations for a common set of definitions, for a framework of training and reviewing physicians in the art, for general methods of reimbursement, and for consistency among clinical trials have been made. Implementation of these recommendations will require additional effort and cooperation from practicing physicians, medical societies, hospital administrations, and industry.

Prognostic factors for hearing preservation in vestibular schwannoma surgery.

OBJECTIVE: To determine whether prognostic indicators for hearing preservation could be identified in patients with vestibular schwannoma undergoing middle fossa craniotomy resection. STUDY DESIGN: Prospective case review. SETTING: Private practice tertiary referral center. PATIENTS: 333 patients with serviceable hearing and vestibular schwannoma resected by middle fossa craniotomy from 1992 to 1998. MAIN OUTCOME MEASURES: Potential prognostic indicators, including tumor size and nerve of origin, preoperative pure-tone average, speech discrimination, distortion product otoacoustic emission testing, age, auditory brainstem response (ABR), and electronystagmography. RESULTS: Postoperative hearing near preoperative levels was attained in 167 patients (50%), with an American Academy of Otolaryngology-Head and Neck Surgery Class A hearing result in 33% and a Class B result in 26%. Comparison of potential prognostic indicators between groups with hearing preserved and the group with no measurable hearing revealed significant differences in preoperative hearing, ABR, and tumor origin data. Better preoperative hearing, shorter intraaural wave V latency, shorter absolute wave V latency, and superior vestibular nerve origin were associated with higher rates of hearing preservation. CONCLUSIONS: Preoperative hearing status, ABR, and intraoperative tumor origin data were shown to be of value as prognostic indicators.

A transgenic insertional inner ear mutation on mouse chromosome 1.

OBJECTIVES/HYPOTHESIS: To clone and characterize the integration site of an insertional inner ear mutation, produced in one of fourteen transgenic mouse lines. The insertion of the transgene led to a mutation in a gene(s) necessary for normal development of the vestibular labyrinth. STUDY DESIGN: Molecular genetic analysis of a transgene integration site. METHODS: Molecular cloning, Southern and northern blotting, DNA sequencing and genetic database searching were the methods employed. RESULTS: The integration of the transgene resulted in a dominantly inherited waltzing phenotype and in degeneration of the pars superior. During development, inner ear fluid homeostasis was disrupted. The integration consisted of the insertion of a single copy of the transgene. Flanking DNA was cloned, and mapping indicated that the genomic DNA on either side of the transgene was not contiguous in the wild-type mouse. Localization of unique markers from the two flanks indicated that both were in the proximal region of mouse chromosome 1. However, in the wild-type mouse the markers were separated by 6.3 cM, indicating a sizable rearrangement. Analysis of the mutant DNA indicated that the entire region between the markers was neither deleted nor simply inverted. CONCLUSIONS: These results are consistent with a complex rearrangement, including at least four breakpoints and spanning at least 6.3 cM, resulting from the integration of the transgene. This genomic rearrangement disrupted the function of one or more genes critical to the maintenance of fluid homeostasis during development and the normal morphogenesis of the pars superior.

Profound hearing loss associated with hydrocodone/acetaminophen abuse.

OBJECTIVES: To describe profound hearing loss associated with hydrocodone overuse and the successful rehabilitation of these patients with cochlear implantation. STUDY DESIGN: Retrospective review. SETTING: A tertiary otologic referral center. PATIENTS: Twelve patients with rapidly progressive hearing loss and a concurrent history of hydrocodone overuse. INTERVENTIONS: Comprehensive medical histories, physical findings, audiometric tests, and, in those patients undergoing cochlear implantation, postimplantation performance data were reviewed. MAIN OUTCOME MEASURES: Clinical characteristics of hydrocodone-related hearing loss and open set word and sentence performance in those patients undergoing cochlear implantation. RESULTS: Hydrocodone overuse was associated with rapidly progressive sensorineural hearing loss in 12 patients. In four patients the initial presentation was unilateral, and two of the patients experienced vestibular symptoms. None of the 12 patients experienced improved thresholds after high-dose prednisone. Seven of the eight patients undergoing cochlear implantation have demonstrated early success with their devices. CONCLUSIONS: Hydrocodone is frequently prescribed in combination with acetaminophen for the relief of pain and has a side effects profile similar to other medications in its class. Although not described previously, overuse or abuse can be associated with a rapidly progressive sensorineural hearing loss. These patients can be successfully rehabilitated with cochlear implantation.

The surgical management of Bell's palsy: a review.

Facial nerve paralysis is a devastating problem for those affected. Few areas in otolaryngology have been as controversial as the management of Bell's palsy. The past several decades have witnessed many theories about the etiology and pathogenesis of Bell's palsy. In concert with each of these theories has been an appropriate management scheme. Because of the nature of the literature, it has been difficult for clinicians to unequivocally outline management algorithms. In the forefront of this debate is the issue of surgical therapy for a subset of these patients. Recent technology has provided some concrete insights into the mechanisms underlying Bell's palsy. Further, new clinical studies, albeit retrospective, support the need to re-evaluate surgery in the treatment of selected patients. The literature regarding the pathophysiology of Bell's palsy and the history of facial nerve surgery for this disease are reviewed.

Six months of desipramine for dysthymia: can dysthymic patients achieve normal social functioning?

BACKGROUND: There is evidence that antidepressant medication improves social dysfunction during acute treatment in dysthymic patients but it is unknown if the gain in social functioning persists or progresses with longer-term antidepressant treatment. We examine the effect of 6 months of desipramine treatment on social functioning in dysthymic patients. METHODS: Forty-six subjects with DSM-III-R dysthymia (70% with superimposed major depression) who had responded to 10 weeks of open-label desipramine (DMI) treatment received 16 additional weeks of continuation DMI. Social functioning was measured at weeks 0, 10 and 26 with the Social Adjustment Scale-Self Report. RESULTS: Euthymia was maintained and a marginally significant trend for further improvement in overall social functioning appeared during continuation treatment. Only 24% of subjects achieved normative level of social adjustment after 6 months of DMI treatment. LIMITATIONS: The main limitation was the lack of a placebo control group. CONCLUSION: Acute improvement in social functioning persists during continuation treatment. However, most dysthymic patients did not achieve a community level of social adjustment. Significant social dysfunction persists in dysthymic patients with low levels of depressive symptomatology after 6 months of intense DMI treatment.